| 252451. |
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| 252452. |
- Karlsson, Andreas
(författare)
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Bootstrap Methods for Bias Correction and Confidence Interval Estimation for Nonlinear Quantile Regression of Longitudinal Data
- 2006
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- This paper examines the use of bootstrapping for bias correction and confidence interval calculations for a weighted nonlinear quantile regression estimator, adjusted to the case of longitudinal data. Different weights, bootstrap methods and types of confidence intervals are used and compared by computer simulation using a four-parameter logistic growth function and error terms following an AR(1) model. Finally the methods are applied to a data set with growth patterns of two genotypes of soybean. It is found that the bias correction reduces the bias, but has the disadvantage of increasing the risk of getting crossing quantile regression curves, and that the bootstrap percentile method and the normal approximation method perform well when used without bias correction. When increasing the autocorrelation in the AR(1) model, the length of the confidence intervals decreases
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| 252453. |
- Karlsson, Anja
(författare)
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Boundary conditions for successful Urban Living Labs
- 2013
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Urban Living Labs are development environments that integrate residents and other stakeholders to develop and test new solutions in their daily life. The users of the new services or solutions are active partners in the whole development process, which happens in the real urban context. Urban Living Labs utilize various co-design methods for understanding the needs, generating solution ideas, presenting ideas and evaluating the solutions in practice. In addition, citizen participation methods are used for participation in decision making and taking action. Key success factors for Urban Living Labs are the early and continuous involvement of the affected people, clear goals and expectations, and acting instead of discussing. The methods must be adapted to the goals and participants. At its best, people can participate in the Urban Living Lab activities as a part of their other activities and see the effects of their participation shortly afterwards.
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| 252454. |
- Karlsson, Anastasia, et al.
(författare)
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Boundary signaling in tonal and non-tonal dialects of Kammu
- 2007
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Ingår i: Proceedings of Fonetik, TMH-QPSR. ; , s. 117-120
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Kammu, a Mon-Khmer language spoken in Northern Laos is a language that has developed lexical tones rather recently, from the point of view of language history. One of the main dialects of this language is a tone language of the “East Asian” type with (high or low) tone on each syllable, while the other main dialect lacks lexical tones. The dialects differ only marginally in other respects. This type of language material allows us to investigate how the existence of lexical tones in a given language influences the use of intonation in that language, especially as a signal for focus and phrasing. We performed an introductory study of phrase intonation in tonal vs. non-tonal dialects of Kammu. As awaited we do find differences in boundary signaling. In both types of dialects the differentiation between (pragmatically) marked and unmarked boundaries is relevant. At marked phrase boundaries we find signaling of focus and of some expressive meanings. The difference between the two types of dialects is in the functional load of the intonational gestures. Thus in the tone dialects pragmatically marked boundaries are assigned high pitch, while in nontonal dialect it is a pitch fall that has a high pragmatic load.
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| 252455. |
- Karlsson, Anna, et al.
(författare)
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Brachiopoda : Armfotingar - Brachiopods
- 2010
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Ingår i: The 2010 Red List of Swedish Species. Rödlistade arter i Sverige 2010. - Uppsala : ArtDatabanken, SLU. - 9789188506351 ; , s. 507 - 509
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 252456. |
- Karlsson, Ann-Christin, 1960-
(författare)
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Att vara vaken under operation i regional anestesi : Från patienters upplevelser till en vårdande modell
- 2013
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Aim: The overall aim of the thesis was to describe the experiences of awake patients during surgery under regional anesthesia. In addition, the aim was to develop a model for intraoperative care that can support and enhance patients’ well-being during the intraoperative period. Methods: Study I was a patient interview study guided by a reflective lifeworld approach. In study II a philosophical reflection of the findings from study I was carried out. In study III a hermeneutic approach inspired by Ricoeur and Gadamer was used in order to interpret video recorded material. In study IV a hermeneutic approach inspired by Gadamer was used to synthesize the findings in studies I-III transformed into an intraoperative caring model. Overall main findings: The analysis shows that being awake during surgery can be compared with walking a tightrope because of ambiguous feelings. The proximity and presence of the nurse anesthetist (NA) anchors the patient in the present and strengthens the patient’s feeling of trust. The temporary disruption in the relationship between the body and the world due to regional anesthesia means that the patient’s being in the world is exposed to revolutionary experiences. Gaps between the patient’s experiences and the situation can be bridged over when the NA acts as the patient’s bodily extension and links the patient as a subject to the world in the intraoperative situation. From the patient’s perspective this calls for the NA’s proximity and genuine presence in the ‘intraoperative caring space’. When the NA’s performance of his/her professional duties clashes with the patient’s existential being in the intraoperative situation the need of present presence from the NA is crucial.Conclusions: The findings contribute to knowledge development about intraoperative care and raise awareness that care for the awake patient cannot be performed on formal routines that might disregard the uniqueness of each patient’s situation. The model can be used as a tool to encounter awake patients’ existential needs in the intraoperative situation and to further enlighten NAs about the possible impact of their proximity, interaction and communication behavior in the delivery of intraoperative nursing care.
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| 252457. |
- Karlsson, Anna-Carin, 1983-
(författare)
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Effects of domestication related genes on behaviour, physiology and gene expression in chickens
- 2014
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Domestication, the process when animals adapt to captivity, tends to modify a whole array of traits towards what has been termed “the domesticated phenotype”, where the domesticated animal differs from its wild ancestor in morphology, physiology, development and behaviour. Physiological traits and behaviours are controlled by genes. One single gene can control several different traits (pleiotropy), be linked to a neighbouring gene on the chromosome, or interact with another gene that in turn controls another trait. This is the explanation why one can select for high egg production and at the same time get a change in the colour of the plumage. The aim of this thesis was to evaluate the effect of a mutation in two particular genes (PMEL17 and TSHR) related to domestication on behaviour, gene expression and other physiologial traits. The animals investigated were chickens from a cross between the ancestral Red Junglefowl (RJF) and the domesticated White Leghorn (WL) selected for high egg production traits. PMEL17 is a gene affecting plumage colour. A mutation in the gene causes a non-pigmented white plumage and has been shown to protect against feather pecking. Our studies showed that a mutation in the PMEL17 gene affects social, explorative and aggressive behaviour in chickens, but not visual ability. The thyroid stimulating hormone receptor (TSHR) plays an important role in the signal transduction of the hypothalamus-pituitary-thyroid axis that has general effects on development, behaviour and reproduction. A mutation in the TSHR gene affects incubation time, domestication related behaviours such as fear and aggression, gene expression, thyroid hormone levels and photoperiodic reproduction responses in chicken. The results from this thesis suggest that a mutation in the PMEL17 and TSHR genes have pleiotropic effects on behaviour and traits related to domestication, and it is therefore likely that both genes have been important for the domestication of the chicken.
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| 252458. |
- Karlsson, Anna-Carin, et al.
(författare)
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The effect of a domestication related mutation in the thyroid stimulating hormone receptor (TSHR) on photoperiodic response and reproduction in chicken
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- The thyroid stimulating hormone receptor (TSHR) has been suggested to be a “domestication locus” in the chicken. A strong selective sweep over the gene in domestic breeds of chicken, but not in the ancestral Red Junglefowl, and significant effects of a mutation in TSHR on domestication related traits in chicken, indicate that the gene has been important for the chicken domestication. The TSHR play a key role in the signal transduction of seasonal reproduction, which is characteristically less strict in domestic animals. We investigated the effect of the mutation on reproductive traits as well as TSHB, TSHR, DIO2 and DIO3 gene expression during altered day length (photoperiod) in females and males intercross chickens homozygous for the mutation (d/d) or wild type homozygotes (w/w). This allowed an assessment of the effect of genotype at this locus against a random mix of RJF and WL genotypes throughout the rest of the genome. The TSHR gene expression was significantly lower in both d/d females and males, in comparison to w/w individuals, indicating a strong effect of the “domestic” mutation on gene expression. The d/d females showed a faster increase in the onset of laying than w/w females, and d/d males showed a reduced response to altered day length in testicular size and significant lower levels of TSHB and DIO3 expression, in comparison to w/w males. Additionally, pure White Leghorn females kept under natural day length in Sweden during December showed active ovaries and significant lower levels of TSHR and DIO3 expression in comparison to Red Junglefowl females kept under similar conditions. Our study suggest that the TSHR mutation affects photoperiodic response in chicken in the direction of being less dependent on seasonal reproduction, a typical domestication feature, and may therefore have been important for the chicken domestication.
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| 252459. |
- Karlsson, Annika C
(författare)
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Viral dynamics and evolution following primary HIV-1 infection
- 2000
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The knowledge of the early events during primary HIV-1 infection (PER) is of great importance for the understanding of the pathogenesis of HIV-1. A major problem in studies on PHI is the limited amount of data accessible from the early time-points. In our study, frequent blood sampling was done during the first weeks at PHI and thereafter in the chronic phase of infection, from both untreated (n = 8) and treated (n = 15) patients. The overall aim of this thesis was to obtain insights in the dynamics of viral load, diversity and divergence during PHI and the subsequent events in the chronic phase of infection, including the conceivable persistence of earlier viral quasispecies in resting CD4+ T-lymphocytes, a proposed reservoir for HIV-1. In untreated patients, a novel four phase model of the HIV-1 RNA dynamics during PHI was described. The initial rapid increase reached a peak one week after onset of symptoms, thereafter a rapid decay was followed at the third week by a reduced viral clearance before a seemingly steady state was reached after about two months. The rapid decay most probably reflects the onset of HIV-1 specific immune activity. The phase of reduced viral clearance may be due to the appearance of escape mutants and/or outgrow of minor transmitted variants. Nevertheless, the decay continued although at a much lower rate suggesting that the immune system continues to respond to the new viral variants resulting in a steady state between replication and clearance. The virus population was characterized mainly by direct sequencing, but also by cloning, of the partial gag, pol, and env genes. Although a completely homogeneous viral population was uncommon the viral diversity was restricted in most patients. However, in some patients a more heterogeneous pattern was identified, which could reflect that several HIV-1 strains were transmitted and/or that an antiretroviral immune response caused a rapid selection of a fit master sequence. In the chronic phase, three patterns of viral sequence variation were identified; a successive replacement of the original major viral sequence due to an accumulating divergence; a highly restricted viral divergence; and a rapid shift to a new major sequence already during the first two months. In the latter case the original major sequence reappeared later simultaneously with clinical deterioration and increased viral load. The reappearance could possibly be due to activation of founder viral quasispecies during perturbation of the immune system or reverse mutations related to a constrained evolution. Independent on the reasons, our results showed that the temporal variation of the viral population differs substantially between individuals. In patients in whom treatment was initiated at a very early stage, only a minor increase of the viral divergence was found during the first six months. Thereafter, no further evolution was detected. Also, the viral quasispecies obtained from resting T-cells, two years after initiation of therapy, were identical to the founder plasma viral population. A continuous decline of the proviral load was found corresponding to a half-life of six months, close to the decay rate of human memory T-lymphocytes. These data suggest that it is possible by early successful antiretroviral intervention to inhibit any significant viral evolution. The reservoir of latently infected resting T-cells in optimally treated patients is considered to be stable, as also confirmed by us in one treated patient. However, there is no knowledge about the replenishment of these cells in untreated and suboptimally treated subjects. Cells were therefore obtained both from patients followed from PHI as well as from multi-therapy experienced patients who previously had developed antiretroviral resistance. In the two patients not receiving any therapy during or after PHI, no original viral sequences were present in the resting memory T-cells almost six years later. Also, only a minority of the earlier identified resistance associated mutations was found in this cellular population of multi-therapy experienced patients. Instead, the viral population in resting T-cells clustered with the plasma sequences obtained at the same occasion, or before initiation on potent antiviral therapy, in five of the seven patients. These results indicate that the pool of latently infected resting T-cells in peripheral blood is continuously replenished even though it is possible that resistant or founder viral strains still are present in a minority of these cells.
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| 252460. |
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