| 1. |
- Nilsson, Lena Maria, 1965-
(författare)
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Sami lifestyle and health : epidemiological studies from northern Sweden
- 2012
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The aim of this PhD thesis was to expand the current knowledge of “traditional Sami” diet and lifestyle, and to test aspects of the Sami diet and lifestyle, specifically dietary pattern, macronutrient distribution and coffee consumption, in population-based epidemiological studies of mortality and incident cardiovascular disease and cancer in a general population.In Paper I, semi-structured interviews were conducted with 20 elderly Sami concerning their parent’s lifestyle and diet 50-70 years ago. Questionnaire data from 397 Sami and 1842 matched non-Sami were also analyzed, using non-parametric tests and partial least square methodology. In Papers II-IV, mortality data and incident cancer data for participants in the Västerbotten Intervention Program (VIP) cohort were used for calculations of hazard ratios by Cox regression. In Paper II, a Sami diet score (0-8 points) was constructed by adding one point for each intake above the median for red meat, fatty fish, total fat, berries and boiled coffee, and one point for each intake below the median for vegetables, bread and fibre. In Paper III, deciles of energy-adjusted carbohydrate (descending) and protein (ascending) intake were added to create a Low-Carbohydrate, High-Protein (LCHP) score (2-20 points). In Paper IV, filtered and boiled coffee consumption was studied in relation to incident cancer. In Paper V, a nested case-control study of filtered and boiled coffee consumption and acute myocardial infarction, risk estimates were calculated by conditional logistic regression.Surprisingly, fatty fish may have been more important than reindeer meat for the Sami of southern Lapland in the 1930’s to 1950’s, and it is still consumed more frequently by reindeer-herding Sami than other Sami and non-Sami. Other dietary characteristics of the Sami 50-70 years ago and present-day reindeer-herding Sami were high intakes of fat, blood, and boiled coffee, and low intakes of bread, fibre and cultivated vegetables (Paper I). Stronger adherence to a “traditional Sami” diet, i.e. a higher Sami diet score, was associated with a weak increase in all-cause mortality, particulary apparent in men (Paper II). A diet relatively low in carbohydrates and high in protein, i.e. a high LCHP score, did not predict all-cause mortality compared with low LCHP score, after accounting for saturated fat intake and established risk factors (Paper III). Neither filtered nor boiled coffee consumption was associated with cancer for all cancer sites combined, or for prostate or colorectal cancer. For breast cancer, consumption of boiled coffee ≥4 versus <1 occasions/day was associated with a reduced risk. An increased risk of premenopausal and a reduced risk of postmenopausal breast cancer were found for both total and filtered coffee. Boiled coffee was positively associated with the risk of respiratory tract cancer, a finding limited to men (Paper IV). A positive association was found between consumption of filtered coffee and the risk of acute myocardial infarction in men (Paper V).In conclusion, the findings of Paper I, in particular the relative importance of fatty fish compared to reindeer meat in the “traditional Sami” diet of the 1930’s-1950’s, suggest that aspects of cultural importance may not always be of most objective importance. The findings of Papers II-V generally did not support health benefits for the factors studied. The relatively good health status of the Sami population is therefore probably not attributable to the studied aspects of the “traditional Sami” lifestyle, but further investigation of cohorts with more detailed information on dietary and lifestyle items relevant for “traditional Sami” culture is warranted.
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| 2. |
- Sjölander, Daniel
(författare)
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Luminescent molecular recognition of pathognomonic and aging associated protein aggregates
- 2014
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Various protein inclusions have been recognized to be associated with aging and pathogenic conditions, such as in Alzheimer’s disease, Parkinson’s disease, Type 2 diabetes, and the prionoses Creutzfeldt-Jakob disease, Chronic wasting disease (CWD), and Mad cow disease. The causative transition of protein aggregation is the alteration in the conformation of the protein that renders the protein susceptible towards self-assembly. Variations in the physico-chemical ultrastructure of the protein deposit, i.e. the conformation and the chemical nature of the fibril constituent protein monomers, translate into specific structure-property phenotype, hence clinicopathology. Upon transmission and/or propagation this phenomenon gives rise to specific protein aggregate strains. Today most potential treatments of the protein conformational diseases have been a huge failure, effectively due to late diagnosis and subsequent therapeutic intervention. An imperative for efficient treatment is early detection and accurate identification for proper clinical diagnosis.The purpose of the studies in this thesis was to develop highly sensitive methods for detection and discrimination of age- and disease associated protein deposits both for in vitro and ex vivo utilization.Herein we have shown that, for in vitro usage, Nile red will bind to amyloid-like protein aggregates derived from a plethora of precursor proteins. It was also found that the fluorescence was insensitive to acidic assay conditions in contrast to the standard in vitro dye Thioflavin T (ThT). Further, Nile red was shown to discriminate between conformational isoforms thus enabling conformational typing of amyloid structures.For the development of ex vivo detection methods we employed luminescent conjugated oligothiophenes (LCOs) and utilized the structure-conformation induced optical properties of this class of protein aggregate ligands. The heptameric oligothiophene h-FTAA was successfully used to detect, with high sensitivity, protein deposits from various systemic amyloidoses (ATTR, AA, AL-λ/κ, and the local amyloidosis AIAPP) derived from biopsy specimens. Also aging-associated protein deposits were detected which was found promising for early detection of potentially pathogenic protein inclusions. Further, LCO staining of tissue sections was found compatible with immunolabeling enabling subtyping of involved proteins. Early detection of amyloidosis also requires relatively non-invasive methods, why h-FTAA staining was directed towards fine-needle-aspirated (FNA) abdominal fat tissue smears. Staining of protein deposits and detection with high sensitivity was also found in the fat tissue smears.In addition to the relatively rare prionoses it has lately been shown that Alzheimer’s, Parkinson’s diseases share similar properties as the prion pathologies. Hence the urgent need for ligands that will recognize specific disease specific strain aggregates. Using an established murine model for prion strain propagation we were able to discriminate two different prion strains, murine adapted Sheep Scrapie (mSS) and murine adapted Chronic wasting disease (mCWD) from each other by using multimodal fluorescence microscopy entailing emission/excitation spectral imaging and fluorescent lifetime imaging (FLIM).In conclusion we have shown that the LCOs will recognize protein aggregates with high sensitivity and selectivity. In addition we have shown that the LCOs detect protein aggregates that Congo red failed to recognize thus allowing potentially early diagnosis. Last, we show that the LCOs will recognize and discriminate between different protein aggregate strains which potentially will allow disease specific therapeutic targeting.
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| 3. |
- Eckeskog, Linn, 1984-
(författare)
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Kommunikation i förskolan : förskollärares och barnskötares kommunikation med föräldrar i ett digitaliserat medielandskap
- 2019
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The overall aim of this doctoral thesis is to study communication work among personnel in Swedish pre-schools, with a particular focus on mediated communication with parents. The purpose is also to analyse what roles are given to the professionals in this communication, to identify what subject positions are constructed and to identify how boundaries are managed within the communication practices.The primary theoretical framework of the thesis is social constructivism and symbolic interactionism. The pre-school organisation and identities are regarded as in a perpetual state of becoming and changes in the media landscape are viewed as rearranging the preconditions for communication practices. Technical innovations are regarded as social products at both ends. Results build upon observations in five pre-schools, interviews with 32 pre-school employees and multimodal analysis of communication material directed to parents. Additional interviews and document studies were conducted in the form of a case study, in order to gain knowledge of the implementation of a digital learning platform.The study shows that the communication environments differ between pre-schools, e.g. concerning how and which mediums are used. Several obstacles to communication are identified, of which many (but not all) are related to the socioeconomic status of parents. Within the mediated communication, pre-school personnel to some extent position themselves as experts concerning practical and pedagogical questions, whilst parents are positioned as actors in need of guidance. A major function of mediated communication is assigning parents’ responsibilities in relation to the pre-school, along with norms regarding what constitutes the “good” (pre-school) parent. Boundary work in relation to parents is conducted using different modalities, used for hedging but also for establishing professional positions. Digitalisation appears as a negative force when introduced top-down, without regards to the needs, previous practices and preconditions within a particular pre- school; but as a positive force when initiated by the professionals themselves and when responding to particular needs within specific pre-schools. As expectations on digitalisation in pre-schools increase, questions of preconditions and communication skills grow in prominence.Although expectations on pre-school professionals’ communication skills are high, communication with parents is not sufficiently acknowledged as part of the actual work in pre-schools. A sign of (and reasons for) the under prioritisation of communication work is the uneven and arbitrary preconditions for communicating, in the forms of relevant education, time and technical equipment. The lack of resources can be connected to three issues: A working environment issue (discrepancy between expectations and preconditions), a democratic issue (communication being random rather than planned/ considered) and a professional issue (multimodal communication not reflecting the professional identity that informants strive towards).Communication with parents (and surrounding society) needs to be acknowledged as part of the work in pre-school, and the personnel need to be given the necessary skills and conditions for communication, in order to provide equality of ac- cess to the parents, but also to give personnel the possibilities of communicating about and reflecting the pre-school organisation as they know it.
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| 4. |
- Sjölander, Jens
(författare)
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Improving Forming of Aerospace Composite Components through Process Modelling
- 2018
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In the aerospace industry there is a constant effort to reduce the weight of aircraft. Since weight reduction has a direct impact on fuel consumption. Reducing the fuel consumption leads to botheconomical benefits through less money spent on fuel and environmental benefits through reduced CO2 emissions. One way that weight savings have been achieved in the last couple of decades is by replacing metals with carbon fiber composites in structural components, where a common choice is unidirectional pre-impregnated (UD prepreg) carbon fiber. Traditionally manufacturing is done by hand lay-up where one ply at a time is laid up on a tool. However the need to make large production volumes feasible has led to a need of automated manufacturing processes. One way to rationalize production is to form the whole laminate at once instead of layer by layer. This is done presently with the single and double diaphragm forming techniques. The challenge with forming of stacked laminates is that the individual plies interact with each other as they conform to the geometry increasing the likelihood of defects to develop. This thesis investigates the effect of forming method and process parameters on the development of manufacturing faults and on the geometry of the finished formed part and studies if these faults can be predicted in numerical simulations. First a method for forming stacked laminates using an industrial robot with methods inspired by human forming techniques is presented. Using this system the effect of different forming sequences on the appearance of wrinkles can be investigated. Forming simulations were done to relate the appearance of wrinkles to ply strains detected in the simulated forming process. The method is used to manufacture joggled spars with a length of 1.4 m and a laminate consisting of 20 plies. Thereafter process simulation of hot drape forming (HDF) is used to determine why wrinkling occurs when plies with specific fiber directions are combined with each other in a stack. This study is supported by an experimental study where plies using two different material systems were mixed in the stack to promote or suppress different types of wrinkles. This leads to the discovery that the wrinkles observed could be divided into two main types: global wrinkles were the whole laminate is under compression due to the geometry, and local wrinkling were wrinkling is initiated by compression of one layer due to interaction with surrounding layers. In the fifth paper the impact of forming method on radius thinning is investigated. By comparing hand lay-up and HDF it is shown that a majority of radius thinning of a laminate can occur already in the forming step if HDF is used. In the last study inter-ply shear of prepreg under a variety of different testing parameters is investigated, including different relative fiber directions between the plies. The study shows that the relative fiber direction is an important parameter to take into account when characterizing inter-ply shear as the force required to shear an interface that has a difference of fiber direction of 0° is significantly higher than the force required to shear interfaces with a difference of 45° and 90°. Taking the difference into account also has a significant impact on the results of forming simulations where models that included the difference in inter-ply shear behavior showed a higher tendency for in-plane wrinkling.
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| 5. |
- Sjölander, Per, 1959-
(författare)
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A sensory role for the cruciate ligaments : regulation of joint stability via reflexes onto the γ-muscle-spindle system
- 1989
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Reflex effects evoked by graded electrical stimulation of the posterior articular nerves (PAN) of the ipsi- and contralateral knee joints were investigated using both micro-electrode recordings from 7 - motoneurones and recordings from single muscle muscle spindle afferents. Spindle afferent responses were also recorded using natural stimulation of different types of receptors, to elucidate if the articular reflexes onto the y -motoneurones were potent enough to significantly alter the muscle spindle afferent activity. Stretches of the ipsilateral posterior (PCL) and anterior (ACL) cruciate ligaments, pressure on the ipsi- and contralateral knee and ankle joint capsules, and passive flexion/extension movements of the joints in the contralateral hind limb were performed. The occurrance of different sensory endings in the ACL and PCL was examined using gold chloride staining for neuronal elements. All experiments were performed on chloralose anaesthetized cats.More than 90% of the static and dynamic y -motoneurones were responsive to electrical stimulation of the PAN. Most 7-cells responded to low intensity electrical stimulation. Excitatoiy reflex effects predominated on both static and dynamic posterior biceps-semitendinosus (PBSt) 7 -cells, while excitatory and inhibitory effects occurred with an about equal frequency on triceps-plantaris (GS) 7-cells. The fastest segmental route for excitatory PAN effects on hind limb 7-motoneurones seems to be di- or trisynaptic, while the path for inhibitory effects seems to be at least one synaps longer.Physiological stimulations of ipsi- and contralateral joint capsules and of ipsilateral cruciate ligaments were all found to evoke frequent and potent changes in spindle afferent responses from the GS and PBSt muscles. It was shown that these effects were due to reflexes onto dynamic and static fusimotor neurones caused by physiological activation of articular sensory endings. Both ipsi- and contralateral joint receptor stimulation evoked excitatory as well as inhibitory fusimotor effects. The highest responsiveness was found during stimulation of the cruciate ligaments, i.e. 58% for GS and 47% for PBSt primary spindle afferents to PCL stimulation, and 73% for GS and 55% for PBSt primary spindle afferents to ACL stimulation. Significant alterations in spindle afferent activity was encountered at very low traction forces applied to the cruciate ligaments (5-10 N). The low thresholds, the tonic character of the stimuli, and the fact that different types of sensory endings were demonstrated in the cruciate ligaments (i.e. Ruffini endings, Pacinian corpuscles, Golgi tendon organ like endings and free nerve endings), indicate that the fusimotor effects observed were caused by activation of slowly adapting mechanoreceptors, most likely Ruffini endings and/or Golgi tendon organ like endings.The potent reflex effects on the muscle spindle afferents elicited by increased tension in the cruciate ligaments indicate that these ligaments may play a more important sensory role that hitherto believed, and it is suggested that they may be important in the regulation of the stiffness of muscles around the knee joint, and thereby for the joint stability. The possible clinical relevance and the mechanisms by which joint receptor afferents, via adjustment of the muscle stiffness, may control joint stability are discussed.
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| 6. |
- Hassler, Sven, 1963-
(författare)
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The health condition in the Sami population of Sweden, 1961-2002 : Causes of death and incidences of cancer and cardiovascular diseases
- 2005
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The Sami people are the Natives of northern Scandinavia. The knowledge of the health and living conditions of the Swedish Sami is extremely limited which is in contrast to the large amount of detailed information on health and socioeconomic issues that is available for other circumpolar Natives. The encounter with the western society and the acculturation process has for many native populations had serious health consequences, causing a dramatic increase of lifestyle related diseases such as cancer, diabetes, stroke, obesity and hypertension as well as a dramatic increase of suicide and drug abuse. The overall objective of this thesis was to investigate the health conditions of the Sami population of Sweden using causes of death and incidences of cancer and cardiovascular diseases (CVD) as health indicators, and to evaluate their possible association with acculturative factors such as assimilation, integration, separation and marginalization. A Sami population was identified containing a total of 41 721 individuals. Specific cohorts were selected from this population for the different studies. A four times as large demographically matched non-Sami control population was used for comparisons. A study of causes of death, 1961-2000, showed small differences in overall mortality and life expectancy between the Sami and the non-Sami. However, Sami men showed significantly lower mortality risks for cancers but higher for external cause of injury and Sami women higher risks for diseases of the circulatory system (CVD) and of the respiratory system. An increased risk of dying from subarachnoid haemorrhage (SAH) was observed among both Sami men and women. The increased risk of dying from accidents among male reindeer herders is suggested to be caused by the increased socioeconomic pressure and the extensive use of terrain vehicles. It is concluded that commercial reindeer management is one of the most dangerous occupations in Sweden. In a study of the cancer risk among the reindeer herding Sami between 1961-1997, an overall lower risk to develop cancers, particularly prostate and malignant lymphoma was observed among the reindeer herding Sami. The risk for stomach cancer was significantly higher in relation to their non-Sami neighbours. The Sami and the non-Sami had similar risk factor-patterns for CVD. The main differences were related to working conditions and lifestyle factors of the reindeer herding Sami - the women showed a more unfavourable risk factor pattern than the men. Higher incidences of stroke were observed among Sami men and women compared to their non-Sami neighbours while the mortality rates of stroke were similar. The mortality ratio of AMI was increased for Sami women in spite of similar incidence ratios. A higher risk of SAH was observed among all groups of Sami. According to traditional socioeconomic risk factors, the differences in the levels of income and education observed between the Sami and the non-Sami, were poorely associated with the disparities of CVD. As has been shown, only minor differences in the health indicators were found between the Sami and their non-Sami neighbours. This is in clear contrast to several other native populations for which the health situation is largely unfavourable in comparison with that of the general population. The observed differences between the Sami and the non-Sami probably reflect differences in lifestyle, psychosocial and genetic factors. The relation between these factors and the acculturation process is dicussed, and it is suggested that separation or segregation of the reindeer herding Sami and the assimilation of the other Sami have influenced the health condition of the Sami, but with the largest impact probably prior to 1961 and the earliest start of follow-up for the studies in this thesis. Thus, the similarities in health between the Sami and the non-Sami 1961-2002, are probably a result of centuries of close interaction that has caused similarities in culture, attitudes and lifestyle, as well as equal accessibility to the health care services and the social security systems.
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| 7. |
- Wiesinger, Birgitta, 1963-
(författare)
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On the relationship between spinal pain and temporomandibular disorders
- 2010
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Both spinal pain and temporomandibular disorders (TMD) commonly occur in the general population. Previous studies demonstrate neurophysiologic and biomechanical couplings between the trigeminal and cervical regions. This investigation tested the null hypothesis of no relationship between spinal pain (neck, shoulder and/or low back) and TMD, by using questionnaires and clinical examinations of the jaw function. In an age- and sex-matched case-control study, the specific aim was to compare the prevalence of signs and symptoms of TMD among cases with long-term spinal pain and controls without spinal pain. The results showed that subjects with spinal pain had signs and symptoms of TMD significantly more often than did controls. The associations remained after excluding all participants with jaw pain. Furthermore, the comorbidity pattern was similar, regardless of location of spinal pain. In a cross-sectional study, the specific aim was to test whether there is a reciprocal cross-sectional dose-response-like relationship between spinal pain and TMD. Two different designs were used, one with frequency/severity of spinal pain as independent variable, and the other, with frequency/severity of TMD symptoms as independent variable. The analysis showed increasing odds for presence of TMD symptoms with increasing frequency/severity of spinal pain, and increasing odds for presence of spinal pain with increasing frequency/severity of TMD symptoms. In a case-control study within a 2-year prospective cohort, the specific aim was to test whether there is a reciprocal temporal relationship between signs and symptoms in trigeminally, and symptoms in spinally, innervated areas. Incidence of symptoms in these areas was analyzed in relation to presence of spinal pain, headaches, and signs and symptoms of TMD at baseline. The main findings were that presence of signs of TMD at baseline increased the onset of spinal pain and symptoms in the trigeminal area, and that spinal pain increased the onset of symptoms in the trigeminal area. An augmentation effect between the significant baseline variables was observed for the incidence of headaches and jaw pain. In conclusion, the investigation demonstrated a cross-sectional and temporal relationship between spinal pain and TMD; thus, the null hypothesis was rejected. The results indicate common pathophysiological mechanisms in the development of spinal pain and TMD. The comorbidity and reciprocal influence that were found call for an integrated and multidimensional approach in the management of individuals with long-term spinal pain and TMD.
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