| 1. |
- Hjalmarsson, Anna, 1976-
(författare)
-
Being provided with a safe haven : Care-dependent older persons' participation in prehospital emergency care
- 2023
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Participation in care is a key concept in many welfare societies and serves to guide clinical practice and adapt care to personal preferences and needs in order to promote well-being and quality of life. Previous research has shown that practicing participation in care is complex due to the concept not being clearly defined. A significant risk is, therefore, that participation in care is practiced based on the professional caregivers' own definitions, which might be inconsistent with the cared-for persons' perceptions of what participation is.Older persons can continue to live in their own homes with the support of municipal home care services that meet everyday care needs. Care-dependent older persons are known to have increased emergency care needs, which in Sweden require inter-organizational and inter-professional collaboration involving a care transfer between welfare levels. This thesis aimed to deepen the understanding of care-dependent older persons' participation in prehospital emergency care from lifeworld and welfare perspectives. The inductive design was based on a lifeworld approach and included triangulation of the phenomenon of participation in care using descriptive, interpretative, and comparative methods.From the perspective of care-dependent older persons, participation in prehospital emergency care means a forced transfer of life responsibility to professional caregivers when being existentially unsafe and incapacitated due to acute illness. Through authorized representation, the professional caregivers act for the older person, with the power to bring about change and create opportunities for existence. Care-dependent older persons' participation in prehospital emergency care involves a deepened dependence that necessitates coexistence and being provided with a 'safe haven' through the entire emergency care chain. A 'safe haven' can be understood as an unconditional, calm, and sheltered interpersonal space for emotional rest that is provided to the older person during an existentially challenging situation. From the perspective of care-dependent older persons, the emergency care chain transcends organizational boundaries and includes mobile safety alarm services and emergency department attendance.The involved professionals must be supported in practicing participation in care based on a comprehensive understanding of the concept, and emergency care options must be aligned with the care-dependent older persons' need for coordinated and continuous care. Collaborative challenges related to unstructured collaboration and professional hierarchy need to be addressed to support well-functioning collaboration in situations involving acutely ill older persons. The involved organizations need to recognize care-dependent older persons' deepened dependence when acutely ill, as well as their extended view of the prehospital emergency care chain.
|
|
| 2. |
- Karlsson, Mattis, 1986-
(författare)
-
From Fossil To Fact : The Denisova Discovery as Science in Action
- 2022
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- From Fossil to Fact: The Denisova Discovery as Science in Action is a study of the (actor) networked relations that make and shape science through the case of the discovery of the Denisova human.In 2010, Nature published the article “The complete mitochondrial DNA genome of an unknown hominin from southern Siberia”, the article revealed the results of mtDNA sequencing of a fossilised finger bone excavated from the Denisova Cave in Siberia, showing that the fossil belonged to an individual of a previously unknown type of humans, the Denisovans. This thesis identifies, describes and analyses how a set of actors and actions – a network – made the Denisovan’s transformation(s) from fossil to fact happen. The study relies on materials regarding the Denisovan from multiple types of sources, such as scientific journals, news articles and Wikipedia entries, which make it possible to describe a collective process of knowledge production that surpasses a science community autonomy, and to highlight the diverse, multidimensional and sophisticated mesh of people, places and things that came together in the making of the Denisova human (as a) fact.Drawing on methodological guidelines and theoretical premises from actor network theory and Bruno Latour’s principles for science in action, this thesis deals with the Denisova discovery as a case of science in the making. The thesis traces actions of significance for the Denisovan’s representation, analysing them as part of a materialisation, to illustrate how the Denisova human was made, and made to fit the major paradigms and narratives of (a)DNA and evolutionary science. The thesis actualises questions about social influence in science, problematising imaginaries of science/non-science divides, and highlights how the authority of genetic science is subject to and dependent on dramatisation.This thesis lists actors and actions that were central to the discovery and the making of the fact. This list includes actors from various fields, showing how the Denisova human was designed to hold in accordance with the rules and cultures of a heterogenous network that includes scientists, experts, journalists and Wikipedia editors.This complicated network made the Denisova human through transformations and drove it to become a fact, allowing it to be written into the history of human evolution. Mapping this network provides an answer to how the Denisova human has been made and remade, but also provides insight into the relationship and roles of science, science news and Wikipedia in the representations of scientific results.
|
|
| 3. |
- Karlsson, Staffan, 1959-
(författare)
-
Older people`s public health care and social services : Functional ability, health complaints, agreement in needs assessment and care satisfaction
- 2008
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The overall aim was to describe and compare functional ability and health complaints of older people receiving municipal care in relation to housing and informal care, and factors associated with medical health care, municipal care and informal care. Further, the aim was to investigate agreement in needs assessments between personnel and older people and to investigate care satisfaction and health-related quality of life among older people receiving municipal care and services. Study I and II included 1958 persons aged 65 years and above, who were assessed for functional ability, health complaints, and level of informal and municipal care and service. Study II in addition included data from a register including medical health care. In study III (n=152), standardised needs assessments were performed by the staff. Later, the older person’s view was collected in a personal interview concerning functional ability, health complaints, public and informal care. In addition (Study IV, n=166), SF-12 was used for measuring health-related quality of life and for measuring care satisfaction. Cohabitation was a predictor of a combination of municipal and informal care at home (OR: 5.935), while assistance with Instrumental Activities of Daily Living (IADL) provided by municipal home care and services predicted municipal care only (OR: 0.344). Care in special accommodation was predicted by advanced age (OR: 1.051), dependency in IADL (OR: 19.883), Personal Activities of Daily Living (PADL) (OR: 02.695), and impaired cognitive ability (OR: 3.849) with receiving municipal care only as a reference. Living alone (OR: 0.106), dependency in IADL (OR: 11.348) and PADL (OR: 2.506), impaired cognitive ability (OR: 3.448), impaired vision or blindness (OR: 1.812) and the absence of slowly healing wounds (OR: 0.407) were predictors of special accommodation with a combination of informal and municipal care at home as a reference. 35% of those with public care at home were admitted to hospital and 76% had contact with outpatient care by physician compared to 26% and 87% respectively of those in special accommodation. Living in special accommodation was associated with more contacts with primary health care (B=0.643) and fewer contacts with specialist care (B=-0.722). Informal care was associated with more contacts with primary health care (B=0.413), specialist care (B=0.787), admissions to (B=0.265) and days in hospital (B=1.573). Agreement for dependency in IADL and PADL varied between good (κ=0.78) and moderate (κ=0.43). Poor agreement was found for dizziness (κw=0.17) and fair agreement for impaired hearing, urinary incontinence, pain, anxiety and depressed mood (κw between 0.21 and 0.37). Older persons reported more health complaints than were found in the personnel’s assessments, although significantly lower estimation was found only for incontinence and vision. Agreement for provided public care at home was poor, while for informal care it varied between very good and moderate. Low care satisfaction was associated with dependency in IADL (B=-1.338 and B=-1.630), impaired mobility (B=-12.579), blindness (B=-26.143), faeces incontinence (B=-11.898 and B=-17.529) and anxiety (B=-6.105 and B=-27.197), while high care satisfaction was associated with dependency in PADL (B=2.109) and receiving informal care with IADL from spouse (B=8.738). In special accommodation, low care satisfaction had to do with continuity, timing, the staff’s personal characteristics and with their ability to give service. At home, the older people were the least satisfied with the staff’s ability to do housework and to give medical care, with the staff’s amount of time and with their own influence over their care.
|
|
| 4. |
- Christiansen, Line, 1986-
(författare)
-
Using Mobile Health Technology to Support Health-related Quality of Life : From the Perspective of Older Adults with Cognitive Impairment
- 2022
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The prevalence of cognitive impairment and illness increases with age. For older adults, maintaining or improving health-related quality of life (HRQoL) in the early stages of cognitive impairment is important to prevent consequences related to the progression of the condition. This thesis aims to identify factors affecting HRQoL and describe how mHealth technology can support HRQoL in older adults with cognitive impairment.Four studies were conducted using quantitative and qualitative approaches. A cross-sectional design was used to identify factors affecting older adults’ HRQoL (Study I) and investigate the relationship between mHealth technology use and self-rated quality of life (QoL) (Study III). A phenomenographical design was used to describe variations in older adults’ perceptions of mHealth technology and its impact on HRQoL (Study II). A prospective longitudinal design was used to examine older adults’ HRQoL changes over time (Study IV).Participants were selected from two longitudinal population studies using a purposive sampling strategy to include those aged 55 years and above with mild cognitive impairment or mild dementia. Data were obtained from questionnaires and semi-structured interviews. Data from the quantitative studies were analysed using statistical analysis, including descriptive and comparative analysis and regression analysis, while data from the qualitative study were examined using phenomenographical analysis in consecutive steps.The results showed that most older adults experienced good HRQoL with regard to both physical and mental health. The likelihood of having good-to-excellent QoL increased with age and was higher among males and those with higher education levels. Those diagnosed with dementia reported poorer HRQoL. Factors associated with low HRQoL included dependency in activities of daily living, receiving informal care and feelings of loneliness and pain. The use of mHealth technology was perceived as supportive in maintaining social interactions and facilitating independent living. The technology literacy levels among the study sample varied significantly. Those who reported having moderate-to-high technical skills and using the internet regularly via mHealth technology had higher odds of experiencing good-to-excellent QoL. No significant changes were observed in the older adults’ HRQoL over time in relation to the non-use and use of a customized mHealth application.The indicators of HRQoL are clinically relevant for the secondary prevention of dementia to help maintain good HRQoL in older adults with incipient cognitive impairment. The technology-related differences reflect the risk of digital exclusion. To improve preconditions for being digitally involved in society, societal initiatives that aim to empower the technology literacy level of older adults are needed.
|
|
| 5. |
- Nord, Andreas, 1976-
(författare)
-
Trädgårdsboken som text 1643–2005
- 2008
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The aim of this thesis is to shed light on the handbook as a multimodal resource from a reader perspective, with the material consisting of 32 Swedish handbooks on gardening from 1643 to 2005. The study draws theoretically on social semiotics and multimodal discourse analysis, as well as dialogism. There is an emphasis on the addressivity of the text, which is taken as a starting point for tracing signs of the intended text use in the design of the texts. The analysis is meaning-based, with the focus placed on functional features in the design of the texts.The first part of the study considers the reading goals afforded by the thematizations conveyed in titles, headings and text type patterns. The core function of these texts turns out to be action orientation, although the more recent books often include sections oriented towards other goals, like shaping individual aesthetic taste. The second part illustrates how the multimodal cohesive patterns in the books afford non-linear reading paths and make the texts searchable, which is enhanced by the presence of devices such as indices and tables of contents. Concentrating on six of the books, the third part of the study maps out the role of the reader that is naturalized by the design of the text, drawing on appraisal theory, and shows the strong, authoritative role taken by the authorial voice. The evaluative patterns naturalize a fact-seeking reading. However, the most recent book, from 1996, emphasizes emotions to a greater extent, naturalizing a parallel reading that invokes sensory experience.The conclusion drawn is that the core characteristics of the handbooks are action orientation, searchability and factuality. As different parallel functions in recent books are discerned, a tendency towards diversity and multifunctionality is described. The range of semiotic resources has also expanded, it is noted, and there is growing support for the view of a tendency towards the visualisation of written texts.
|
|
| 6. |
- Karlsson, Linn
(författare)
-
The Internal Flow in Freezing Water Droplets
- 2020
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The aim of this work has been to study the internal flow in freezing water droplets on a cold surface and to investigate the different heat transfer mechanisms involved. This is an interesting topic with a great number of applications, specifically in areas where the prevention of unwanted icing is important, e.g. in the case of airplane wings and propellers, wind turbine rotor blades, and roads surfaces.Combining experimental and numerical methods, this study uses Computational Fluid Dynamics (CFD) to build a model of the freezing process and Particle Image Velocimetry (PIV) to aid for a better understanding of the freezing process. For the numerical part of the study, a model of a droplet with a rigid boundary was created where only the interior was of interest and different boundary conditions on the droplet surfaces were used to induce a flow inside the droplet. The heat transfer mechanisms studied was conduction, natural convection and Marangoni convection. For comparison, an experimental method was developed to visualize the movement of the water and to estimate the velocities inside the droplet. In order to compensate for the refraction at the droplet surface a velocity correction method was applied. The internal flow in freezing droplets was also compared to the internal flow in evaporating droplets. The results show that the freezing time is not affected considerably between experiments and the numerical model when including different heat transfer mechanisms, instead the size and contact angle to the surface as well as the substrate temperature are the largest contributors. The direction of the flow and the velocity of the water are highly dependent on the heat transfer mechanisms and these are more difficult to mimic in the numerical model. In the experimental work it was found that the flow is controlled by Marangoni convection for a short time period in the beginning of the freezing process. After this, natural convection instead dominates the flow. When including only conduction and natural convection in the numerical model it can be seen that the gravity effects are most pronounced around the density maximum for water (at T = 4°C). When introducing Marangoni convection in the model the highest velocities are seen in the beginning of freezing. It was found that neither only natural convection nor only Marangoni convection could in itself describe the flow seen in the experimental work. In previous research it has been shown that Marangoni convection is reduced approximately 100 times in the real water droplets compared to theory. This condition yields the best correspondence between numerical results to the experimental results, although there are still differences that have to be investigated further. For evaporating droplets, the Marangoni convection seems to have a little or no effect on the flow.The main conclusion is that it is possible to work with a simplified CFD model and still capture the main flow features and freezing characteristics in freezing water droplets. Furthermore, an experimental method for studying the freezing droplets and for comparison of the numerical work has also been constructed with good results. For the future it would be interesting to further develop the CFD model for even better correspondence with the experimental work and to unravel the differences between theory and real droplets.
|
|
| 7. |
- Persson, Mats, 1987-, et al.
(författare)
-
Subpixel x-ray imaging with an energy-resolving detector
- 2018
-
Ingår i: Journal of Medical Imaging. - : SPIE - International Society for Optical Engineering. - 2329-4302 .- 2329-4310. ; 5:1
-
Tidskriftsartikel (refereegranskat)abstract
- The detector pixel size can be a severe limitation in x-ray imaging of fine details in the human body. We demonstrate a method of using spectral x-ray measurements to image the spatial distribution of the linear attenuation coefficient on a length scale smaller than one pixel, based on the fact that interfaces parallel to the x-ray beam have a unique spectral response, which distinguishes them from homogeneous materials. We evaluate the method in a simulation study by simulating projection imaging of the border of an iodine insert with 200 mg/ml I in a soft tissue phantom. The results show that the projected iodine profile can be recovered with an RMS resolution of 5% to 34% of the pixel size, using an ideal energy-resolving detector. We also validate this method in an experimental study by imaging an iodine insert in a polyethylene phantom using a photon-counting silicon-strip detector. The results show that abrupt and gradual transitions can be distinguished based on the transmitted x-ray spectrum, in good agreement with simulations. The demonstrated method may potentially be used for improving visualization of blood vessel boundaries, e.g., in acute stroke care.
|
|
| 8. |
- Westman, Anna-Karin, 1967-
(författare)
-
Meningsskapande möten i det naturvetenskapliga klassrummet
- 2016
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Bakgrund Syftet med denna avhandling är att få veta mer om hur elever skapar mening i mötet med innehållet i skolans naturvetenskap. De resultat som presenteras i avhandlingen är resultat som visar hur eleverna uttrycker sig under utvalda interaktioner från naturvetenskaplig undervisning. Elevernas uttryck för meningsskapande jämförs också med vad som tidigare forskning rapporterat som svårt i skolans naturvetenskap. Lärandet betraktas genomgående som en sociokulturell aktivitet.Metoder För att kunna besvara frågan om hur ett meningsskapande uttrycks har elevernas uttalanden under interaktioner karaktäriserats kvalitativt och med objektet för undervisningen i förgrunden. Datainsamlingen har gjorts med ljud- eller videoinspelningar. Ämnesinnehållet i interaktionerna är i fokus och hur eleverna samtalar om genetik, cellandning, blodomlopp eller genomförandet av en laboration är centralt i avhandlingens delstudier. De deltagande eleverna är från grundskolans årskurs fem, årskurs nio och från gymnasiet.Resultat Resultaten visar en variation i hur ofta elever diskuterar och uttrycker någon egen mening om de naturvetenskapliga förklaringsmodellerna. När elever konstruerar begreppskartor med utvalda begrepp uttrycker gruppen sitt meningsskapande på sätt som många gånger närmar sig det vetenskapliga. En undervisningsfilm presenterar många vetenskapliga förklaringsmodeller av blodomloppets funktion, men få av dem används av eleverna i det efterföljande samtalet. I interaktioner under laborationer uttrycker elever inte så ofta ett meningsskapande av de naturvetenskapliga förklaringsmodellerna.Sammanfattning Avhandlingens delstudier ger prov på flera tillfällen när eleverna diskuterar ett meningsskapande av de naturvetenskapliga förklaringsmodellerna. Det finns också exempel när förklaringsmodellerna inte diskuteras, även om de för en skolad naturvetare helt uppenbart presenteras. En viktig faktor för att elevernas naturvetenskapliga meningsskapande ska ske är i studierna om undervisningen uppmärksammar hur naturvetenskapliga förklaringsmodeller knyter samman synliga fenomen med molekylära förklaringar och symboler. En annan faktor är om undervisningen lyfter fram naturvetenskapens sätt att kommunicera. Ytterligare en viktig faktor för att de naturvetenskapliga förklaringsmodellerna ska bli ett verktyg för elevernas meningsskapande är om det nya innehållet knyter an till elevernas tidigare vardagserfarenheter eller erfarenheter från tidigare undervisning.
|
|
| 9. |
- Öberg, Sandra, 1974-
(författare)
-
The Hit-IT project : The development and evaluation of an internet-based complex intervention for primary healthcare patients with cardiovascular disease and insomnia
- 2022
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- There is a need to explore insomnia among patients with cardiovascular disease (CVD), since they have increased risk for disease deterioration, poor quality of life and a shorter lifetime expectancy. Cognitive behavioral therapy (CBT) is the main recommended insomnia treatment, although it is a rare treatment choice in the healthcare due to lack of certified CBT therapists.The aim of the thesis was therefore to investigate a nurse-led internet-based CBT for insomnia (I-CBTI) tailored for patients with CVD, that includes qualitative and quantitative measures to explore the patients’ characteristics and treatment motive, insomnia experience, treatment effect, adherence and the usability of a complex intervention called the Hit-IT program.The first paper had a mixed study design to investigate the participants (n=126) sleep, physical and psychological characteristics in relation to insomnia via baseline questionnaires, as well as interviews (n=19) covering their motivation and expectations when participating in the Hit-IT treatment study. The second paper was a qualitative study using a Critical incident technique, to capture the experience of the participants (n=20) with CVD and insomnia sleep situation, and determine how they managed their insomnia. The third paper included 48 participants who were randomised to test the nine-week nurse-led I-CBTI treatment, tailored for patients with CVD or a three-week of self-studies (control group) without support. Paper four was a qualitative study to explore the experience and management of the Hit-IT program.The thesis findings showed that the participants were primarily male participants of older age, and that insomnia symptoms were significantly associated with worse somatic symptom severity, reduced physical quality of life, increased levels of depressive symptoms and cardiac anxiety. The participants were motivated to engage in the Hit-IT study, but were concerned the comorbid condition would be a hindering factor for the required behavioral change if randomized to the nine-week Hit-IT program. The participants also experience physical and cognitive insomnia triggers caused by cardiac symptoms at night. However, the participants in the Hit-IT program group significantly improved their insomnia symptoms compared to the three-week self-study control group. Also, the participants adherent to the Hit-IT program significantly increased their physical quality of life compared to those not adherent to treatment. Moreover, the results showed that the participants had trust in the Hit-IT program and experienced the intervention as very interesting yet challenging. The major treatment adherence facilitator was to experience improved sleep during the course of treatment.The thesis findings conclude that nurses have the skills to deliver a nurse-led I-CBTI treatment, tailored for patients’ with CVD with a sleep improvement outcome. The findings also confirm that primary healthcare patients of older age living with CVD and insomnia, are interested in and able to use internet-based complex interventions to improve their sleep.
|
|
| 10. |
- Danielsson, Mats, Professor, et al.
(författare)
-
Detector for x-ray imaging
- 2019
-
Patent (populärvet., debatt m.m.)abstract
- Disclosed is an edge-on photon counting detector and a method for manufacturing a charge collecting side of such detector. The edge-on photon counting detector comprises a semi-conducting substrate. The semi-conducting substrate comprises, a first end adapted to face an x-ray source and a second end opposite the first end in the direction of incoming x-rays, and at least one strip having N depth segments, N≥2, each of the depth segments comprising a charge collecting metal electrode and a charge collecting side comprising doped regions and insulating regions, wherein each of the charge collecting metal electrodes is arranged over a corresponding doped region and is connected to a respective routing trace arranged on the insulating regions, the respective routing trace being adapted to conduct signals from the charge collecting metal electrode to a read-out pad E, connectable to front-end electronics, arranged at the second end.
|
|
| 11. |
|
|
| 12. |
- Danielsson, Mats, Professor, et al.
(författare)
-
Modular x-ray detector
- 2019
-
Patent (populärvet., debatt m.m.)
|
|
| 13. |
|
|
| 14. |
|
|
| 15. |
|
|
| 16. |
|
|
| 17. |
|
|
| 18. |
|
|
| 19. |
- Grenklo, Staffan, 1959-
(författare)
-
Cross-linked Profilin:actin - A tool to study actin dynamics in non-muscle cells
- 2004
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The microfilament system, consisting of actin and a number of auxiliary proteins, is fundamental for cell motility. Its dynamic organization depends on receptor-mediated signals, leading to rapid polymerizations and depolymerizations of actin. Profilin binds to non-filamentous actin, inhibits spontaneous filament formation, and functions as a regulator of actin polymerization. The profilin:actin complex, is thought to be the principal source of actin for filament formation although the role of profilin is not fully elucidated. In this thesis, a cross-linked profilin:actin complex (PxA), that retains the properties of ordinary profilin:actin, except for being non-dissociable, has been used to characterize the role of profilin and profilin:actin in non-muscle cells. A rapid screening method, employing PxA and based on the far western technique and mass-spectrometry, was designed to identify cellular components that specifically bind profilin:actin. Microinjection of PxA into cells infected with the bacteria Listeria monocytogenes impaired bacterial motility but a mutant PxA, unable to bind proline-rich sequences had no effect, demonstrating that profilin:actin is vital for the activity of the actin polymer-forming complex that the pathogen recruits to its surface upon infection. Fluorescence microscopy using two distinct sets of affinity-purified actin and profilin antibodies generated against PxA enabled localization of monomeric actin in cells. One of the actin and both profilin antibodies resulted in a dotted pattern of fluorescence partially aligning with microtubules whereas the other actin antibody detected filamentous actin. The result demonstrates extensive variability in epitope recognition, and indicates that unpolymerized actin, i.e. profilin:actin and maybe other complex-bound forms of actin, distributes in small packages that might be transported along microtubules. Microinjection of PxA into lamprey axons demonstrated the involvement of actin polymerization during synaptic signaling.
|
|
| 20. |
- Karlsson, Urban, 1967-
(författare)
-
GABA-, glycine- and glutamate-induced currents in rat medial preoptic neurons : functional interactions and modulation by capsaicin
- 2007
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The medial preoptic nucleus (MPN) of the hypothalamus plays a major role in many functions involved in maintaining bodily homeostasis, such as thermoregulation and osmoregulation, as well as in the control of complex behaviours, e.g. sexual behaviour. A fundamental basis for the control and execution of these functions is the synaptic communication between neurons of the MPN. However, the functional properties of the synapses involved are largely unknown. The present thesis is a study of ligand-gated ion channels involved in the pre- and post-synaptic aspects of neuronal communication in the MPN of rat. The aim was to clarify synaptic properties in the MPN, to identify the major channel types involved and to obtain a better understanding of their functional properties. By fast application of agonists to isolated neurons, it was first demonstrated that all neurons responded to glutamate with currents mediated by α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors, and a majority of neurons also with currents mediated by N-Methyl-D-aspartate (NMDA) receptors. All neurons also responded to γ-aminobutyric acid (GABA) and glycine with currents mediated by GABAA receptors and glycine receptors, respectively. These findings show that fast-acting excitatory and inhibitory amino-acid transmitters are most likely important for communication between hypothalamic neurons. Application of agonists to isolated neurons revealed cross-talk, detected as an apparent cross-desensitization, between the responses to GABA and those to glycine. Parallel analysis of current and conductance, using gramicidin-perforated patches to avoid perturbing intracellular chloride concentration, showed that the cross-talk was not dependent on a direct interaction between the receptors as previously suggested, but was a consequence of the change in the intracellular chloride concentration during receptor activation. Strengthened by a computer model, the analysis also showed that the current decay in the presence of GABA or glycine was mainly due to a change in the chloride driving force and that receptor desensitization played a minor role only. The role of thermo-sensitive transient receptor potential TRPV1 channels in the regulation of glutamate- and GABA-mediated transmission was studied in the slice preparation, where much of the synaptic connections between neurons are preserved. It was shown that application of the TRPV1 agonist capsaicin increased the frequency of excitatory AMPA receptor- mediated as well as inhibitory GABAA receptor-mediated postsynaptic currents. This effect was partly presynaptic and demonstrates that TRP channels play a role in regulating synaptic transmission in the MPN. The results imply that such mechanisms may possibly contribute to the thermoregulation by MPN neurons.
|
|
| 21. |
- Liu, Xuejin, et al.
(författare)
-
Count rate performance of a silicon-strip detector for photon-counting spectral CT
- 2016
-
Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - : Elsevier. - 0168-9002 .- 1872-9576. ; 827, s. 102-106
-
Tidskriftsartikel (refereegranskat)abstract
- A silicon-strip detector is developed for spectral computed tomography. The detector operates in photon counting mode and allows pulse-height discrimination with 8 adjustable energy bins. In this work, we evaluate the count-rate performance of the detector in a clinical CT environment. The output counts of the detector are measured for x-ray tube currents up to 500 mA at 120 kV tube voltage, which produces a maximum photon flux of 485 Mphotons/s/mm(2) for the unattenuated beam. The corresponding maximum count-rate loss of the detector is around 30% and there are no saturation effects. A near linear relationship between the input and output count rates can be observed up to 90 Mcps/mm(2), at which point only 3% of the input counts are lost. This means that the loss in the diagnostically relevant count rate region is negligible. A semi-nonparalyzable dead-time model is used to describe the count-rate performance of the detector, which shows a good agreement with the measured data. The non-paralyzable dead time tau(n) for 150 evaluated detector elements is estimated to be 20.2 +/- 5.2 ns. (C) 2016 Elsevier B.V. All rights reserved.
|
|
| 22. |
- Peterson, Tomas, senior professor, 1950-, et al.
(författare)
-
Changes in Athletic Performance in Children Attending a Secondary School with a Physical Activity Profile
- 2022
-
Ingår i: Sports. - : MDPI. - 2075-4663. ; 10:5, s. 71-71
-
Tidskriftsartikel (refereegranskat)abstract
- The longitudinal and multidisciplinary research project Malmö Youth Sport Study measured the sports results achieved by two cohorts of pupils using a variable named ACHIEVE, dividing the pupils into three categories (an elite group competing at the national or international level, a group competing at the district level, and a third group either not competing at all or below district level). This was assessed three and six years after baseline at age 13. An additional hypothetical measure, based on information from the athletes’ trainers, predicted the category the pupils were expected to belong to after twelve years (age 25). Social variables related to the ACHIEVE variable are sex, socio-economic position of the parents, ethnicity, completed secondary sports school, sports capital, and quartile of birth. After three years, 28% of the pupils belonged to the elite group and after six years, 26%. Thirty-two and 48%, respectively, had abandoned their elite efforts. The elite group remained fairly stable over time but fewer girls than boys advanced to the elite group. The pupils at the school have a homogenous middle-class background. We found little evidence that socio-economic factors affected ACHIEVE. Nearly all parents had been engaged in sports, either competing or as coaches. On admission to the school, there was a pronounced relative age effect (RAE). This remained after three years as the age was significantly different between the three groups but was reduced after six years. According to the prognosis made by the coaches, the elite group would be considerably smaller when the subjects reached the age of 25. The RAE was again significant in the prognosis. A further follow-up when the subjects are 25 years old will reveal not only what proportion of subjects are actively competing, but also if they are engaged in recreational sports, to what extent the RAE is present, and how accurately coaches can predict success.
|
|
| 23. |
- Svenmarker, Staffan, 1951-
(författare)
-
Heparin coating and cardiotomy suction in cardiopulmonary bypass
- 2003
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The present thesis addresses various means of reducing inflammatory responses associated with cardiopulmonary bypass (CPB) and retransfusion of pericardial suction blood (PSB) during cardiac surgery. Four (I-IV) prospective randomised controlled clinical trials comprising 475 patients were performed in the following areas: effects of heparin coating on measures of clinical outcome and memory function (I, II), inflammatory reactions in PSB and its systemic effects after retransfusion using cardiotomy suction or cell salvage (III) and effects of retransfusion of PSB on memory function and release patterns of protein S100B (IV). The use of heparin coated CPB-circuits was associated with a decrease of postoperative blood loss (I, II), transfusion requirements (II), shorter stay in hospital (I) decreased postoperative ventilator time (I), lower incidences of atrial fibrillation (II) and neurological deviations (I), reduction in releases of protein S100B (I, II) and lower postoperative creatinine elevation (I, II). PSB contained high concentrations of cytokines, complements, myeloperoxidase, free plasma haemoglobin and protein S100B (III, IV). Retransfusion using cardiotomy suction increased the systemic concentrations of free plasma haemoglobin and protein S100B, whereas retransfusion using cell salvage caused no detectable systemic effects (III, IV). CPB was associated with a small but significant release of protein S100B, despite elimination of PSB-contained protein S100B using cell salvage (IV). Subtle signs of impaired memory function were identified that were not associated with the use of heparin coated CPB-circuits (I, II) or retransfusion of PSB (IV). Key words: cardiopulmonary bypass, oxygenators, heparin, S100 proteins, blood loss, haemostasis, memory, outcome and process assessment.
|
|
| 24. |
- Wiklund, Karin, 1957-
(författare)
-
Establishment, Growth and Population Dynamics in two Mosses of Old-growth Forests
- 2004
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Biodiversity in forests depends on long canopy continuity and existence of different elements which function as substrates for varying organisms. Bryophytes often occupy specific substrates with a patchy distribution. The aim of this thesis was to increase the ecological knowledge about two threatened moss species; Buxbaumia viridis, inhabiting decaying wood, and Neckera pennata, inhabiting bark of base-rich deciduous trees. Establishment from spores was investigated in Buxbaumia viridis and Neckera pennata and models were created to predict germination of spores as a function of pH and water potential. The effects of pH, phosphorus and nitrogen concentration were studied in Buxbaumia viridis, both on spore germination and on sporophyte occurrences in the field. Colony growth in relation to precipitation and microhabitat variables was studied in Neckera pennata, and a model was used to predict growth of colonies over time. Metapopulation dynamics of Buxbaumia viridis were analyzed as an effect of precipitation, habitat quality and patch quantity. A spatial explicit patch occupancy model was constructed to simulate metapopulation sizes and extinction risk over 100 years.The quality of the substrate was very important for spore establishment. Germination success increased with increasing pH in both species. Buxbaumia viridis was less sensitive to low pH than Neckera pennata when water was freely available. However, there was a strong interaction between pH and water potential in prediction of the final cumulative germination: the spores reacted positively to one factor only when the other factor was in a favourable range.Precipitation, moisture holding capacity and interference competition were the main factors affecting colony growth of Neckera pennata. Buxbaumia viridis showed large fluctuations in number of occupied patches among years. Both colonizations and extinctions were highly related to precipitation. Spore germination and sporophyte occurrences in the field were positively related to phosphorus concentration and pH of the substrate.
|
|
