| 1. |
- Gunnarsson, Fredrik, et al.
(författare)
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Channel Characterization and HSDPA Bit Rate Prediction of a Dense City Network
- 2009
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Ingår i: Proceedings of the 69th IEEE Vehicular Technology Conference. - 9781424425174
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Konferensbidrag (refereegranskat)abstract
- In radio network simulations, the channel model is one of the key inputs and it has a large impact on the network performance, especially for HSDPA. When evaluating the benefits of different features in system simulations it is therefore important that the chosen channel model is a good approximation of the radio environment of the evaluated type of area. In this paper an assessment of the radio channel characteristics in a densely planned European city center is presented. Live traffic measurements are compared to "real network" simulations results using a range of different channel models. The results show that the 3GPP Typical Urban channel model does not reproduce the measured performance from the dense urban environment in a good way; only half the capacity compared to what was calculated from the measurements was achieved. Instead, ITU Pedestrian A models the environment in a better way.
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| 2. |
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| 3. |
- Johansson Borg, Anette
(författare)
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Effects and mechanisms of actions of cyclosporin, FK506 and 15-deoxyspergualin
- 1995
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Immunosuppressive drugs can be used to deal with unwanted or inappropriate immune reactions, such as the rejection of a transplanted organ. However, treatment with these drugs are often associated with serious adverse effects, and therefore less toxic immunosuppressants are desired. The aims of the present study were to evaluate the immunologic effects of cyclosporin-sulphate, FK506 and 15-deoxy-spergualin (DSG). CsA-sulphate, a previously unidentified CsA metabolite, is present in high concentration in the bile and plasma of transplanted patients. In vitro and in vivo studies showed that this metabolite has limited immunosuppressive effects. It is likely that the mother compound is responsible for both the immunosuppressive and adverse effects associated with treatment. FK506 is structurally completely distinct from CsA, but was found to have identical immunosuppressive effects in vitro, although at l0-l00 times lower concentrations. Based on studies of combinations of the two drugs, the effects CsA and FK506 are stipulated to be additive. The similar and additive effects of the drugs indicate that they share a common mechanism of action. The prevailing theory is that the drugs first bind to their respective immunophilin. The drug-immunophilin complexes inhibit the calcineurin-mediated dephosphorylation and thus the translocation to the nucleus of the cytoplasmic component of the transcription factor NF-AT. DSG have immunosuppressive properties that are distinct from CsA and FK506, but its mechanism of action remains elusive. In a safety-study, where DSG was given in combination with methyl-prednisolone as treatment of acute graft rejection in kidney transplant recipients, the effects of DSG on blood mononuclear cells were studied. DSG decreased the number of leukocytes, and results indicated that DSG may affect B-cells and perhaps also CD4+ cells. Our in vitro studies confirmed an effect of DSG on the development of cytotoxic T cells. DSG also suppressed the proliterative responses to S. aureus and PHA, if added within 24 hours after stimulation. These effects could be explained by a DSG-dependent reduced Il-6 production. However, addition of recombinant Il-6 only partly restored the development of cytotoxic T-cells, and thus, additional Il-6 independent steps should be DSG-sensitive in the differentiation of CTL. In the transplantation of fetal porcine islet cells, reactivity against the graft is likely to have been induced via the indirect activation pathway of immune recognition. CsA was found to be less efficient in inhibiting the cytotoxicity induced by xenogeneic porcine Iymphocytes via the indirect as compared to the direct pathway. In contrast, DSG inhibited the induction of cytotoxicity equally, irrespective of activation pathway. Although DSG did not suppress antibody production to pig PBL in mice completely, it was more efficient than CsA. DSG may act by modulating the activities of the heat shock proteins Hsc70 and Hsp90. This thesis adds to the knowledge of the effects and mechanisms of action of cyclosporin, FK506 and DSG, knowledge that may be valuable for the optimal treatment of transplant recipients, and in the further development of immuno-suppressive drugs.
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| 4. |
- Lohmander, Anette, et al.
(författare)
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Reliability of auditory perceptual assessment of hypernasality in speech using different scales
- 2018
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Ingår i: Fechner Day 2018. - : International Society for Psychophysics. ; , s. 43-44
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Auditory-perceptual assessment has been criticized because of its inherent subjectivity. However, perceptual judgments are the primary tool in the clinical assessment of voice and resonance parameters and a key task for the speech–language pathologist/therapist (SLP/T). Decision on treatment or further examination is based on the perceptual speech assessment which need to be reliable. Of all perceptual dimensions used to distinguish normal from abnormal speech the most difficult to judge reliably is hypernasality (Watterson et al., 2017). Nevertheless, the final decision regarding whether an individual has nasality or other speech problems is based on the listener’s subjective measurement (Moll, 1λ64). Nasality is present in normal voice production and refers to perceived nasal sounds arising from the coupling of the oral and nasal resonating cavities. Nasal consonants are common in the languages. Normal nasal resonance has a range of acceptability and is perceived along a continuum, while nasal resonance disorders are associated with defects or dysfunction in the palate. In the current study the reliability of perceptual assessment of hypernasality with three different methods were compared. Standardised audio recordings of 5-year-old Swedish-speaking children with repaired cleft palate consisting of 73 stimuli in three different randomised orders were perceptually assessed by four experienced speech-language pathologists using three different methods: a sort and rate procedure (VISOR) allowing comparison between and ordering stimuli along a visual analogue scale; a 2- step method beginning with determination whether the speech resonance is within normal range or not. If not, the stimulus is rated along a 3 point ordinal category scale; a combined category-ratio scale (Borg centiMax®(cM)), where verbally well-defined categories are levelanchored to a ratio scale. Each listener completed a total of 657 hypernasality ratings (73 stimuli in 3 orders by 3 methods) for the rating task. Good to excellent intra-rater reliability was found within each listener for all methods. The highest inter-rater reliability was demonstrated for VISOR and the Borg cM. High consistency within each method was found with the highest for the Borg cM. In conclusion, both the VISOR and the Borg centiMax® seem appropriate for auditory-perceptual assessment of hypernasality with similar and high reliability. However, the Borg cM showed slightly better consistency and seems easiest to use in a clinical setting. Further research should aim for valid definitions of how hypernasality corresponds to the categories along the scale.
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| 5. |
- Paciello Yamashita, Renata, et al.
(författare)
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Reliability of Hypernasality Rating : Comparison of 3 Different Methods for Perceptual Assessment
- 2018
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Ingår i: The Cleft Palate-Craniofacial Journal. - : SAGE Publications. - 1055-6656 .- 1545-1569. ; 55:8, s. 1060-1071
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Tidskriftsartikel (refereegranskat)abstract
- Objective: To compare reliability in auditory-perceptual assessment of hypernasality for 3 different methods and to explore the influence of language background.Design: Comparative methodological study. Participants and Materials: Audio recordings of 5-year-old Swedish-speaking children with repaired cleft lip and palate consisting of 73 stimuli of 9 nonnasal single-word strings in 3 different randomized orders. Four experienced speech-language pathologists (2 native speakers of Brazilian-Portuguese and 2 native speakers of Swedish) participated as listeners. After individual training, each listener performed the hypernasality rating task. Each order of stimuli was analyzed individually using the 2-step, VISOR and Borg centiMax scale methods.Main Outcome Measures: Comparison of intra- and inter-rater reliability, and consistency for each method within language of the listener and between listener languages (Swedish and Brazilian-Portuguese).Results: Good to excellent intra-rater reliability was found within each listener for all methods, 2-step:kappa = 0.59-0.93; VISOR: intraclass correlation coefficient (ICC) = 0.80-0.99; Borg centiMax (cM) scale: ICC = 0.80-1.00. The highest inter-rater reliability was demonstrated for VISOR (ICC = 0.60-0.90) and Borg cM-scale (ICC = 0.40-0.80). High consistency within each method was found with the highest for the Borg cM scale (ICC = 0.89-0.91). There was a significant difference in the ratings between the Swedish and the Brazilian listeners for all methods.Conclusions: The category-ratio scale Borg cM was considered most reliable in the assessment of hypernasality. Language background of Brazilian-Portuguese listeners influenced the perceptual ratings of hypernasality in Swedish speech samples, despite their experience in perceptual assessment of cleft palate speech disorders.
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