| 1. |
- Bengtsson, Per Erik, et al.
(författare)
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Dual-broadband rotational cars measurements in an IC engine
- 1994
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Ingår i: Symposium (International) on Combustion. - 0082-0784. ; 25:1, s. 1735-1742
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Tidskriftsartikel (refereegranskat)abstract
- This is the first report of pure rotational coherent anti-Stokes Raman spectroscopy (CARS) measurementsin an internal combustion (IC) engine. Single-shot, dual-broadband rotational CARS (DB-RCARS) spectra were recorded both prior to ignition and in the postcombustion gases. From these spectra, both temperature and relative oxygen concentrations were evaluated. The pressure was registered simultaneously with the CARS measurements in the spark-ignition engine burning natural gas and air. Prior to ignition, normally at temperatures below 1000 K and pressures below 2 MPa, a rotational CARS spectrum is very temperature sensitive, and the technique can be used for temperature measurements with high accuracy. Evaluated temperatures show a negligible dependence on uncertainties in parameters such as the nonresonant susceptibility of the gas and the slit width. Moreover, no collisional narrowing of the lines has to be taken into account. The relative standard deviation of evaluated temperatures and of relative oxygen concentrations from single-shot measurements were as low as 1, and 1.4-1.9%, respectively. In the postcombustion gases at temperatures above 2000 K and pressures above 1.5 MPa, the nonresonant CARS background gave a large contribution to the total spectrum. In this temperature and pressure range, the evaluated values of temperature and nonresonant susceptibility are not independent, and the nonresonant susceptibility had to be fixed at a precalculated value to get a reliable temperature evaluation. The avantages and disadvantages of rotational CARS in comparison with vibrational CARS for IC engine measurements are discussed.
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| 2. |
- Stiernström, Sara, et al.
(författare)
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Improved understanding of key elements governing the toxicity of energy ash eluates
- 2013
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Ingår i: Waste Management. - : Elsevier BV. - 0956-053X .- 1879-2456. ; 33:4, s. 842-849
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Tidskriftsartikel (refereegranskat)abstract
- Ash from incinerated waste consists mainly of a complex mixture of metals and other inorganic elements and should be classified based on its inherent hazardous effects according to EUs Waste Framework Directive. In a previous study, we classified eight eluates from ash materials from Swedish incineration plants, both chemically and ecotoxicologically (using bacteria, algae, crustacean and fish). Based on measured concentrations in the eluates together with literature acute toxicity data on the crustacean Nitocra spinipes we identified six elements (i.e. Zn, Cu, Pb, Al, K and Ca) potentially responsible for the observed ecotoxicity. However, comparing the used test methods with N. spinipes, the acute test was relatively insensitive to the eluates, whereas the (sub)chronic test (i.e. a partial life cycle test, investigating larval development ratio) was very sensitive. The overall aim of this follow-up study was to verify if the pinpointed elements could be responsible for the observed (sub)chronic toxicity of the eluates. Individual effect levels (i.e. NOEC values) for these six elements were therefore generated using the (sub)chronic test. Our results show that for six of the eight eluates, the observed ecotoxicity can be explained by individual elements not classified as ecotoxic (Al, K and Ca) according to chemical legislation. These elements will not be considered using summation models on elements classified as ecotoxic in solid material for the classification of H-14, but will have significant implications using ecotoxicological test methods for this purpose.
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| 3. |
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| 7. |
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| 8. |
- Berggren, Eric, et al.
(författare)
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Continuous Track Stiffness Measurement : An Effective Method To Investigate The Structural Conditions Of The Track
- 2002
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Ingår i: Railway Engineering Conference.
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Konferensbidrag (refereegranskat)abstract
- Vertical track stiffness and its variations along the track are important parameters that affect the conditionof the track, in particular the deterioration of track geometry and ballast degradation. The track stiffness isalso an important factor that has to be considered when upgrading the track for traffic of higher axle loads and higher speeds. Within the EU project EUROBALT II, Banverket (Swedish National Rail Administration) has developed a method to continuously measure the vertical track stiffness. Recently,Banverket has made further improvement of the method and carried out extensive measurements in Sweden using our track-loading test vehicle. Different combinations of excitation frequency and speedhave been tested. The measurement results have shown a significant correlation with actual geotechnical conditions and depth of soil layers. The measurement method has also shown very good repeatability. In this paper, we introduce the method of continuous track stiffness measurement and report the promising results we have obtained. It can be concluded that the continuous track stiffness measurement provides an effective way to investigate the structural condition of the track and should be a very useful tool for determining the cause of certain track problems.
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| 9. |
- Berglund, David, et al.
(författare)
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Screening of mortality in transplant patients using an assay for immune function
- 2011
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Ingår i: Transplant Immunology. - : Elsevier BV. - 0966-3274 .- 1878-5492. ; 24:4, s. 246-250
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: So far, the ImmuKnow Immune Cell Function Assay (Cylex, Inc., Columbia, MD, USA) has been used to assess risks of infection and rejection in transplant patients. We hypothesized that the ImmuKnow assay might be used for mortality screening in transplant patients overall. METHODS: In the period of February 2007 to December 2009, at the Uppsala University Hospital, 362 patients who received either kidney, kidney+pancreas, kidney+islet cells, liver or liver+kidney allografts were randomly screened using the ImmuKnow assay. All causes of mortality were compared between two groups: patients with at least one ImmuKnow assay below 175ng/mL and patients with all ImmuKnow assays from 175ng/mL and above. Subsequently, the frequency of rejection within thirty days of the ImmuKnow assay was compared between these two groups. RESULTS: The study included 1031 ImmuKnow assays obtained from the 362 patients. A total of 111 patients had at least one ImmuKnow below 175ng/mL and 251 patients had all their ImmuKnow assays from 175ng/mL and above. By January 31st 2010, 16 of 111 patients (14.4%) with at least one ImmuKnow assay below 175ng/mL were deceased, compared to 13 of 251 patients (5.2%) with all ImmuKnow assays from 175ng/mL and above (p=0.0053, Fisher's exact test). There was no difference in the frequency of rejection between the two groups (19.8% versus 17.5%, p=0.66). CONCLUSIONS: In addition to assessing relative risks of infection and rejection in transplant patients, the ImmuKnow assay may be used to identify patients with increased risk of short-term mortality. Transplant patients being highly overimmunosuppressed as assessed by the ImmuKnow assay do not seem to have a lower risk of short-term rejection.
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| 10. |
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| 11. |
- Faxén, Karl-Filip, et al.
(författare)
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Multicore computing--the state of the art
- 2009
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- This document presents the current state of the art in multicore computing, in hardware and software, as well as ongoing activities, especially in Sweden. To a large extent, it draws on the presentations given at the Multicore Days 2008 organized by SICS, Swedish Multicore Initiative and Ericsson Software Research but the published literature and the experience of the authors has been equally important sources. It is clear that multicore processors will be with us for the foreseeable future; there seems to be no alternative way to provide substantial increases of microprocessor performance in the coming years. While processors with a few (2–8) cores are common today, this number is projected to grow as we enter the era of manycore computing. The road ahead for multicore and manycore hardware seems relatively clear, although some issues like the organization of the on-chip memory hierarchy remain to be settled. Multicore software is however much less mature, with fundamental questions of programming models, languages, tools and methodologies still outstanding.
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| 12. |
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| 13. |
- Gardeström, Johanna, et al.
(författare)
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A multilevel approach to predict toxicity in copepod populations : Assessment of growth, genetics, and population structure
- 2006
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Ingår i: Aquatic Toxicology. - : Elsevier BV. - 0166-445X .- 1879-1514. ; 79:1, s. 41-48
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Tidskriftsartikel (refereegranskat)abstract
- One of the goals of environmental risk assessment (ERA) is to understand effects of toxicant exposure on individual organisms and populations. We hypothesized that toxicant exposure can reduce genetic diversity and alter genotype composition, which may ultimately lead to a reduction in the average fitness of the exposed population. To test this hypothesis, we exposed a copepod, Nitocra psammophila, to a toxic reference compound and assayed resulting alterations in genetic structure, i.e. expected heterozygosity and percent polymorphic loci, as well as other population- and fitness-related measures, i.e. population abundance, demographic structure and juvenile growth. The copepods were exposed to 0.11-1.1 mu g of the pentabromo-substituted diphenyl ether (BDE-47) mg(-1) freeze-dried algae for 24 days (i.e. > 1 generation). There was no significant decline in total population abundance. However, there were significant alterations in population structure, manifested as diminished proportion of nauplii and increased proportion of copepodites. In addition, individual RNA content in copepodites decreased significantly in exposed individuals, indicating declined growth. Finally, in the exposed populations, heterozygosity was lower and genotype composition was altered compared to the controls. These results therefore confirm the hypothesized reduction in overall genetic variability resulting from toxicant exposure. Multilevel approaches, such as the one used in the present study, may help unravel subtle effects on the population level, thus increasing the predictive capacity of future ERA.
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| 14. |
- Gardeström, Johanna, et al.
(författare)
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Evidence of population genetic effects of long-term exposure to contaminated sediments : A multi-endpoint study with copepods
- 2008
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Ingår i: Aquatic Toxicology. - : Elsevier BV. - 0166-445X .- 1879-1514. ; 86:3, s. 426-436
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Tidskriftsartikel (refereegranskat)abstract
- In the environment, pollution generally acts over long time scales and exerts exposure of multiple toxicants on the organisms living there. Recent findings show that pollution can alter the genetics of populations. However, few of these studies have focused on long-term exposure of mixtures of substances. The relatively short generation time (ca. 4–5 weeks in sediments) of the harpacticoid copepod Attheyella crassa makes it suitable for multigenerational exposure studies. Here, A. crassa copepods were exposed for 60 and 120 days to naturally contaminated sediments (i.e., Svindersviken and Trosa; each in a concentration series including 50% contaminated sediment mixed with 50% control sediment and 100% contaminated sediment), and for 120 days to control sediment spiked with copper. We assayed changes in FST (fixation index), which indicates if there is any population subdivision (i.e., structure) between the samples, expected heterozygosity, percent polymorphic loci, as well as abundance. There was a significant decrease in total abundance after 60 days in both of the 100% naturally contaminated sediments. This abundance bottleneck recovered in the Trosa treatment after 120 days but not in the Svindersviken treatment. After 120 days, there were fewer males in the 100% naturally contaminated sediments compared to the control, possibly caused by smaller size of males resulting in higher surface: body volume ratio in contact with toxic chemicals. In the copper treatment there was a significant decrease in genetic diversity after 120 days, although abundance remained unchanged. Neither of the naturally contaminated sediments (50 and 100%) affected genetic diversity after 120 days but they all had high within treatment FST values, with highest FST in both 100% treatments. This indicates differentiation between the replicates and seems to be a consequence of multi-toxicant exposure, which likely caused selective mortality against highly sensitive genotypes. We further assayed two growth-related measures, i.e., RNA content and cephalothorax length, but none of these endpoints differed between any of the treatments and the control. In conclusion, the results of the present study support the hypothesis that toxicant exposure can reduce genetic diversity and cause population differentiation. Loss of genetic diversity is of great concern since it implies reduced adaptive potential of populations in the face of future environmental change
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| 15. |
- Grandin, Börje, et al.
(författare)
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Heat Release in the End-Gas Prior to Knock in Lean, Rich and Stoichiometric Mixtures With and Without Egr
- 2002
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Ingår i: SAE Technical Papers. - 0148-7191.
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Tidskriftsartikel (refereegranskat)abstract
- SI Engine knock is caused by autoignition in the unburnt part of the mixture (end-gas) ahead of the propagating flame. Autoignition of the end-gas occurs when the temperature and pressure exceeds a critical limit when comparatively slow reactions - releasing moderate amounts of heat - transform into ignition and rapid heat release. In this paper the difference in the heat released in the end-gas - by low temperature chemistry - between lean, rich, stochiometric, and stoichiometric mixtures diluted with cooled EGR was examined by measuring the temperature in the end-gas with Dual Broadband Rotational CARS. The measured temperature history was compared with an isentropic temperature calculated from the cylinder pressure trace. The experimentally obtained values for knock onset were compared with results from a two-zone thermodynamic model including detailed chemistry modelling of the end-gas reactions.
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| 16. |
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| 19. |
- Hahlbeck, Edda, 1971-
(författare)
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The juvenile three-spined stickleback : model organism for the study of estrogenic and androgenic endocrine disruption in laboratory and field
- 2004
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Industrial and domestic sewage effluents have been found to cause reproductive disorders in wild fish, often as a result of the interference of compounds in the effluents with the endocrine system. This thesis describes laboratory-based exposure experiments and a field survey that were conducted with juveniles of the three-spined stickleback, Gasterosteus aculeatus. This small teleost is a common fish in Swedish coastal waters and was chosen as an alternative to non-native test species commonly used in endocrine disruption studies, which allows the comparison of field data with results from laboratory experiments.The aim of this thesis was to elucidate 1) if genetic sex determination and differentiation can be disturbed by natural and synthetic steroid hormones and 2) whether this provides an endpoint for the detection of endocrine disruption, 3) to evaluate the applicability of specific estrogen- and androgen-inducible marker proteins in juvenile three-spined sticklebacks, 4) to investigate whether estrogenic and/or androgenic endocrine disrupting activity can be detected in effluents from Swedish pulp mills and domestic sewage treatment plants and 5) whether such activity can be detected in coastal waters receiving these effluents.Laboratory exposure experiments found juvenile three-spined sticklebacks to be sensitive to water-borne estrogenic and androgenic steroid substances. Intersex – the co-occurrence of ovarian and testicular tissue in gonads – was induced by 17β-estradiol (E2), 17α-ethinylestradiol (EE2), 17α-methyltestosterone (MT) and 5α-dihydrotestosterone (DHT). The first two weeks after hatching was the phase of highest sensitivity. MT was ambivalent by simultaneously eliciting masculinizing and feminizing effects. When applying a DNA-based method for genetic sex identification, it was found that application of MT only during the first two weeks after hatching caused total and apparently irreversible development of testis in genetic females. E2 caused gonad type reversal from male to female. E2 and EE2 induced vitellogenin - the estrogen-responsive yolk precursor protein, while DHT and MT induced spiggin – the androgen-responsive glue protein of the stickleback.None of the effluents from two pulp mills and two domestic sewage treatment plants had any estrogenic or androgenic activity. Juvenile three-spined sticklebacks were collected during four subsequent summers at the Swedish Baltic Sea coast in recipients of effluents from pulp mills and a domestic sewage treatment plant as well as remote reference sites. No sings of endocrine disruption were observed at any site, when studying gonad development or marker proteins, except for a deviation of sex ratios at a reference site.The three-spined stickleback – with focus on the juvenile stage – was found to be a sensitive species suitable for the study of estrogenic and androgenic endocrine disruption.
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| 20. |
- Hahlbeck, Edda, et al.
(författare)
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The juvenile three-spined stickleback (Gasterosteus aculeatus L.) as a model organism for endocrine disruption I : Sexual differentiation
- 2004
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Ingår i: Aquatic Toxicology. - : Elsevier BV. - 0166-445X .- 1879-1514. ; 70:4, s. 287-310
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Tidskriftsartikel (refereegranskat)abstract
- Juvenile three-spined stickleback (Gasterosteus aculeatus L.) is introduced as a unique model organism for both androgenic and oestrogenic endocrine action. Intersex is often used as an indicator for disruption of sexual differentiation in fish exposed to different kinds of effluents from human activities. In wild fish it has exclusively been reported in terms of feminisation due to xenoestrogens in the environment. The assumption that the intersex individuals are feminised genetic males can only be proven by genetic sex identification of the intersexual individuals. Intersex and gonadal sex reversal were induced in three-spined sticklebacks by treatment with natural and synthetic steroid hormones. Juvenile sticklebacks were exposed to three nominal concentrations of 17β-oestradiol (E2); i.e. 0.01, 1.0 and 10.0 μg/L; which were administered to the water either continuously from hatching to the end of the experiment (39–58 days post hatch), during the first 2 weeks after hatching only, from 14 days after hatching onwards, or during the chorionated embryo stage until hatching. Other groups were exposed to 17α-ethinylestradiol (EE2) at 0.05 μg/L and 17α-methyltestosterone (MT) at 1.0 μg/L (nominal concentrations). MT was applied continuously, during the first 2 weeks post hatch only, or from 14 days after hatching onwards. Gonad histology was examined and the genetic sex was identified with male sex-linked PCR markers. Treatment with oestrogens caused feminisation at the two highest E2 concentrations and with EE2. Exposure to E2 before hatching had no effect. Intersexual individuals from oestrogen treatments were genetic males. The genetic sex marker identified apparent total reversal of the gonad type of genetic males. Treatment with MT did not reveal a clear picture, since intersex was observed in both genetic females and males. MT also caused severe testis abnormalities, mainly the development of large branched cavities with unidentified origin. The process of sex differentiation is most sensitive to the influence of external steroids during the first 2 weeks after hatching. A lower incidence of intersex could also be induced in sticklebacks exposed from 14 days after hatching by E2 treatment, but not with MT. The combination of gonad histopathology with genetic sex identification in juvenile sticklebacks is suggested as a tool for detecting endocrine disruption in laboratory studies, and might become very useful in field surveys.
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| 21. |
- Hahlbeck, Edda, et al.
(författare)
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The juvenile three-spined stickleback (Gasterosteus aculeatus L.) as a model organism for endocrine disruption II : kidney hypertrophy, vitellogenin and spiggin induction
- 2004
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Ingår i: Aquatic Toxicology. - : Elsevier B.V.. - 0166-445X .- 1879-1514. ; 70:4, s. 311-326
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Tidskriftsartikel (refereegranskat)abstract
- This study investigated the suitability of juvenile three-spined sticklebacks, Gasterosteus aculeatus L., for detecting both androgen- and oestrogen-induced endocrine disruption. The investigated endpoints were kidney hypertrophy and the induction of the protein markers spiggin and vitellogenin. Juveniles were exposed to steroid hormones 17β-oestradiol (E2: nominal 0.01, 1.0 and 10 μg/L), 17α-ethinylestradiol (EE2: nominal 0.05 μg/L) and 17α-methyltestosterone (MT: nominal 1.0 μg/L) from the day of hatching until the termination of the experiments between 39 and 58 days after hatching. E2 (10 μg/L) and MT were applied during different time windows: (a) 14 days after hatching only and (b) continuously with start 14 days after hatching. Kidney hypertrophy is an androgen-dependent secondary sexual character in adult male sticklebacks and corresponds to the production of the glue protein spiggin during the breeding season. The kidneys were hypertrophied and spiggin levels were elevated in juvenile sticklebacks after treatment with MT. Paradoxically, slightly elevated spiggin levels and kidney hypertrophy were observed also in fish treated with high dose E2. Levels of vitellogenin, the oestrogen-inducible yolk precursor protein, were elevated in juvenile sticklebacks after E2 medium and high dose and EE2 treatment. The tested endpoints are suitable for the study of endocrine disruption in juvenile sticklebacks, a fish species that is easy to handle in laboratory and relevant for temperate geographical regions.
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| 22. |
- Holmer, Helene, et al.
(författare)
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Fracture incidence in GH-deficient patients on complete hormone replacement including GH
- 2007
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Ingår i: Journal of Bone and Mineral Research. - : Wiley. - 0884-0431 .- 1523-4681. ; 22:12, s. 1842-1850
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Tidskriftsartikel (refereegranskat)abstract
- Fracture risk in GHD patients is not definitely established. Studying fracture incidence in 832 patients on GH therapy and 2581 matched population controls, we recorded a doubled fracture risk in CO GHD women, but a significantly lower fracture risk in AO GHD men. Introduction: The objective of this study was to evaluate fracture incidence in patients wilh confirmed growth hormone deficiency (GHD) on replacement therapy (including growth hormone [GH]) compared with population controls, while also taking potential confounders and effect modifiers into account. Materials and Methods: Eight hundred thirty-two patients with GHD and 2581 matched population controls answered a questionnaire about fractures and other background information. Incidence rate ratio (IRR) and 95% CI for first fracture were estimated. The median time on GH therapy for childhood onset (CO) GHD men and women was 15 and 12 yr, respectively, and 6 and 5 yr for adult onset (AO) GHD men and women, respectively. Results: A more than doubled risk (IRR, 2.29; 95% CI, 1.23-4.28) for nonosteoporotic fractures was recorded in women with CO GHD, whereas no risk increase was observed among CO GHD men (IRR. 0.61) and AO GHD women (IRR, 1.08). A significantly decreased incidence of fractures (IRR, 0.54; 95% CI 0.34-0.86) was recorded in AO GHD men. Conclusions: Increased fracture risk in CO GHD women can most likely be explained by interaction between oral estrogen and the GH-IGF-I axis. The adequate substitution rate of testosterone (90%) and GH (94%) may have resulted in significantly lower fracture risk in AO GHD men.
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| 23. |
- Holmer, Helene, et al.
(författare)
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Nonfatal stroke, cardiac disease, and diabetes mellitus in hypopituitary patients on hormone replacement including growth hormone
- 2007
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Ingår i: Journal of Clinical Endocrinology and Metabolism. - : The Endocrine Society. - 1945-7197 .- 0021-972X. ; 92:9, s. 3560-3567
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Tidskriftsartikel (refereegranskat)abstract
- Context: The impact of long-term GH replacement on cerebrovascular and cardiovascular diseases and diabetes mellitus in hypopituitary patients is unknown. Objective: The incidence of nonfatal stroke and cardiac events, and prevalence of type 2 diabetes mellitus ( T2D) and cardioprotective medication were compared between cohorts of GH-deficient (GHD) patients and population controls. Design and Participants: The incidence of nonfatal stroke and cardiac events was estimated retrospectively from questionnaires in 750 GHD patients and 2314 matched population controls. A prevalence of T2D and cardioprotective medication was recorded at the distribution of questionnaires. Time since first pituitary deficiency to start of GH therapy was 4 and 2 yr, and time on GH therapy was 6 yr for GHD women and men, respectively. Results: Lifelong incidence of nonfatal stroke was tripled in GHD women and doubled in GHD men, but a decline was seen in both genders during periods after first pituitary hormone deficiency and GHD, during which most patients had GH therapy. The lifelong incidence of nonfatal cardiac events declined in GHD men during first pituitary hormone deficiency and GHD periods. GHD women had a higher prevalence of T2D and lipid-lowering medication, whereas GHD men had a higher prevalence of antihypertensive medication. Conclusions: The declined risks of nonfatal stroke in both genders and of nonfatal cardiac events in GHD men during periods on GH replacement may be caused by prescription of cardioprotective drugs and 6-yr GH replacement. GHD women had an increased prevalence of T2D, partly attributed to higher body mass index and lower physical activity.
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| 24. |
- Holmer, Helene, et al.
(författare)
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Psychosocial health and levels of employment in 851 hypopituitary Swedish patients on long-term GH therapy
- 2013
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Ingår i: Psychoneuroendocrinology. - : Elsevier. - 0306-4530 .- 1873-3360. ; 38:6, s. 842-852
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Tidskriftsartikel (refereegranskat)abstract
- Context: The psychosocial health and working capacity in hypopituitary patients receiving long-term growth hormone (GH) therapy are unknown. less thanbrgreater than less thanbrgreater thanObjective: Psychosocial health and levels of employment were compared between GH deficient (GHD) patients on long-term replacement and the general population. less thanbrgreater than less thanbrgreater thanDesign and participants: In a Swedish nationwide study, 851 GHD patients [101 childhood onset (CO) and 750 adult onset (AO)] and 2622 population controls answered a questionnaire regarding current living, employment and educational level, alcohol consumption and smoking habits. The median time on GH therapy for both men and women with CO GHD was 9 years and for AO GHD 6 years, respectively. less thanbrgreater than less thanbrgreater thanResults: As compared to the controls, the GHD patients were less often working full time, more often on sick leave/disability pension, and to a larger extent alcohol abstainers and never smokers (all; P andlt; 0.05). Predominantly CO GHD women and men, but to some extent also AO GHD women and men, lived less frequently with a partner and more often with their parents. Particularly AO GHD craniopharyngioma women used more antidepressants, while AO GHD men with a craniopharyngioma used more analgesics. less thanbrgreater than less thanbrgreater thanConclusions: A working capacity to the level of the general population was not achieved among hypopituitary patients, although receiving long-term GH therapy. Patients were less likely to use alcohol and tobacco. The CO GHD population lived a less independent life.
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| 25. |
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| 26. |
- Karimi, Mahssa, et al.
(författare)
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Increased neck soft tissue mass and worsening of obstructive sleep apnoea after growth hormone treatment in men with abdominal obesity : Growth hormone and obstructive sleep apnoea in abdominally obese men
- 2010
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Ingår i: Journal of Clinical Sleep Medicine. - 1550-9389. ; 6:3, s. 256-263
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Tidskriftsartikel (refereegranskat)abstract
- Background Risk factors for obstructive sleep apnea (OSA) are male gender, obesity and abnormalities in neck soft tissue mass. OSA is associated with both growth hormone (GH) excess and severe GH deficiency in adults. Adults with abdominal obesity have markedly suppressed GH secretion. Aim To study the effect of GH treatment on OSA in abdominally obese men with impaired glucose tolerance. Patients and Methods Forty men with abdominal obesity and glucose intolerance were randomized in a prospective, 12-month, double-blind trial to receive either GH or placebo. The treatment groups had similar BMI and waist circumference. Overnight polysomnography and computed tomography to assess muscle and fat distribution in the neck and abdomen were performed at baseline and after 12 months. Results GH treatment increased insulin-like growth-factor-1 from (mean (SD)) 168(17) to 292(28) μg/L, the apnea-hypopnea index from (n/h) 31(20) to 43(25) and oxygen-desaturation index from (n/h) 18(14) to 29(21) (p=0.0001, 0.001, 0.002). Neck transverse diameter, circumference and total cross-sectional area (p=0.007, 0.01, 0.02) increased while abdominal visceral adipose tissue (p=0.007) was reduced. No between-group differences in total sleep time, REM sleep, non-REM sleep and time spent in supine position were found. The Epworth sleepiness scale score was unchanged. Conclusions GH treatment increased the severity of OSA in abdominally obese men. The possible mechanism appears to be reflected by the GH-induced increase of measures of neck volume. The present results, to some extent, argue against that low GH/IGF-I activity is a primary cause of OSA in abdominally obese men.
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| 27. |
- Olsson, Daniel S, 1983, et al.
(författare)
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Tumour recurrence and enlargement in patients with craniopharyngioma with and without GH replacement therapy during more than 10 years of follow-up.
- 2012
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Ingår i: European journal of endocrinology. - 1479-683X. ; 166:6, s. 1061-8
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Tidskriftsartikel (refereegranskat)abstract
- Most patients who have been treated for craniopharyngioma (CP) are GH deficient (GHD). GH replacement therapy (GHRT) may stimulate tumour regrowth; and one of the concerns with long-term GHRT is the risk of tumour progression. Therefore, the objective was to study tumour progression in CP patients on long-term GHRT.Case-control study.The criteria for inclusion of cases were: i) GHD caused by CP; ii) GHRT >3 years; and iii) regular imaging. This resulted in 56 patients (mean age at diagnosis 25±16 years) with a mean duration of GHRT of 13.6±5.0 years. As controls, 70 CP patients who had not received GHRT were sampled with regard to follow-up, gender, age at diagnosis and initial radiation therapy (RT).The 10-year tumour progression-free survival rate (PFSR) for the entire population was 72%. There was an association (hazard ratio, P value) between PFSR and initial RT (0.13, 0.001) and residual tumour (3.2, 0.001). The 10-year PFSR was 88% for the GHRT group and 57% for the control group. Substitution with GHRT resulted in the following associations to PFSR: GHRT (0.57, 0.17), initial RT (0.16, <0.001), residual tumour (2.6, <0.01) and gender (0.57, 0.10). Adjusted for these factors, the 10-year PFSR was 85% for the GHRT group and 65% for the control group.In patients with CP, the most important prognostic factors for the PFSR were initial RT and residual tumour after initial treatment. Long-term GHRT did not affect the PFSR in patients with CP.
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| 28. |
- Olsson, Jenny, et al.
(författare)
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Miljöövervakningsprojekt i Södertälje kanalområde för bedömning av effekterna från muddring och tippning av förorenade sediment. Multivariat utvärdering av toxiciteten mot brackvattenorganismer exponerade för sediment från Hallsfjärden - Delrapport 3
- 1999
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- I det kontrollprogram som har följt efter muddringen i Södertälje kanal har analyser gjorts av metaller och PAH i bottenvatten och sediment. Toxiciteten av ämnen i vattenfasen utlösta från sedimenten mot aborryngel, paddyngel, pungräka och dammsnäcka har analyserats. Dessa organismer ger en god bild av effekterna i ekosystemet eftersom de representerar djurgrupperna; fisk, groddjur, kräftdjur och snäckor. För att studera hur föroreningarna har påverkat toxiciteten i området har en multivariat utvärdering gjorts för att hitta eventuella korrelationer mellan toxicitet och föroreningar utlösta i vattenfasen. Datamaterialet baseras på sedimentdata från 5 provtagningspunkter varav 4 provtagningspunkter är belägna i Hallsfjärden, söder om Södertälje, och en referenspunkt i Forsmark, norra Uppland. De uppmätta effekterna på de olika organismerna ger en grov bild av det som lösts ut till vattenfasen från sedimenten. Det begränsade antalet provtagningspunkter innebär att resultaten av den multivariata utvärderingen måste beaktas med viss försiktighet. Resultatet av utvärderingen visade att toxiciteten är störst vid Fläsklösa och vid Halls Holme belägna i Hallsfjärden. Vid Halls Holme är toxiciteten i vattenfasen hög för abboryngel. Fläsklösa ger inte lika entydiga resultat vid jämförelse med Halls Holme. Utvärderingen visade att både utlösta metaller och PAH har en toxisk effekt på de undersökta organismerna. PAH påverkar främst abborryngel. Paddyngel påverkas både av metaller och PAH. Vissa variabler för pungräka påverkas av metaller och andra av PAH medan dammsnäckan inte verkar påverkas nämnvärt av de analyserade föroreningarna.
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| 29. |
- Olsson, Jenny, et al.
(författare)
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Miljöövervakningsprojekt i Södertälje kanalområde för bedömning av effekterna från muddring och tippning av förorenade sediment. Validering av spridningsmodell för kvicksilver i Hallsfjärden - delrapport 4
- 1999
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- SMHI har utarbetat en spridningsmodell för kvicksilver (Hg) i Hallsfjärden söder om Södertälje. Modellen baseras på omblandningsmekanismer i brackvattenmassan, sötvattenflödet från Mälaren samt kvicksilver-flödet från sedimenten. Modellen prognosticerar total kvicksilverhalter i vattenmassan och har kalibrerats med data från fältprovtagningar av vatten och laboratorieförsök med sediment. Det finns minst två möjliga källor till det kvicksilver som uppmätts i Hallsfjärden, kvicksilver som avgår från sediment i Hallsfjärden och kvicksilver som kommer med vattnet från Igelstaviken och Mälaren. Kvicksilverflöden från sediment för flera provtagningspunkter har använts vid utvärderingen. Modellen baseras på flödet vid tipplatsen direkt efter tippningarna av förorenade sediment avslutats. Övertäckningen av de förorenade sedimenten med renare sand har medfört att ytskiktet innehåller lägre koncentration Hg jämfört med andra lokaler i Hallsfjärden. Detta innebär att det finns provtagningspunkter i Hallsfjärden med större avgång av Hg från bottnarna. Modellens relevans för dessa lokaler har även studerats. För i stort sett samtliga värden på flödet från sedimenten gav SMHIs modell kvicksilverhalter i bottenvattnet som är lägre än uppmätta halter. Modellen kunde förklara ca 20-100% av Hg-halterna vid syrefattiga (anaeroba) förhållanden vid de olika lokalerna. Vid syrerika förhållanden vid omblandning vår och höst kunde endast 5-20% förklaras av modellen. Av det uppmätta kvicksilvret beräknas ca 15% härstamma från sediment i Hallsfjärden både under stagnation och omblandning i vattenmassan. Resterande kvicksilver antas komma från förorenade sediment norr om Halls holme alternativt via diffus spridning från atmosfären.
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| 30. |
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| 31. |
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| 32. |
- Preuss, Thomas G., et al.
(författare)
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AN INDIVIDUAL-BASED MODELING APPROACH FOR EVALUATION OF ENDPOINT SENSITIVITY IN HARPACTICOID COPEPOD LIFE-CYCLE TESTS AND OPTIMIZATION OF TEST DESIGN
- 2011
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Ingår i: Environmental Toxicology and Chemistry. - : Wiley. - 0730-7268 .- 1552-8618. ; 30:10, s. 2353-2362
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Tidskriftsartikel (refereegranskat)abstract
- In the present study, an individual-based model for Nitocra spinipes was developed and used to optimize the test design of a proposed Organisation for Economic Co-operation and Development test guideline for harpacticoid copepods. The variability between individuals was taken into account, based on measured data, leading to stochastic model output. Virtual experiments were performed with the model to analyze the endpoint sensitivity and the effect of number of replicates and inspection intervals on statistical power. The impact of mortality was evaluated; most sublethal effects could not be determined if the mortality was >= 70%. Most sensitive to mortality was the determination of effects on brood size, for which the statistical power was reduced at 10% mortality. Our simulations show that increasing the number of replicates from 72 to 96 or 144 has little impact on the statistical power, whereas 25 replicates disallow relevant endpoint detection. Furthermore, it was demonstrated that the proposed ID inspection interval can be shifted to a 3D interval, without losing statistical power. It was demonstrated that developmental endpoints have a higher statistical power than reproductive endpoints in the current test design. The present study highlights the usefulness of individual-based models for optimizing the experimental design. The use of such models in the development of standard test guidelines will lead to a faster and less resource-demanding process.
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| 33. |
- Ragnvaldsson, Daniel, 1976-
(författare)
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Hazard screening of contaminated sites : bioavailable fractions and biological in vitro tools
- 2007
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The environmental bioavailability of contaminants, rather than their total concentrations in the soil compartment play a decisive role for the risks associated with contaminated sites. Various soil constituents and abiotic conditions have strong influence on bioavailability, which may vary substantially between different locations. It is therefore necessary to site-specifically use tools that reflect the fractions of contaminants that are available to biota and pose the highest potential environmental risks. Bioassays provide integrated toxic responses which include effects from unknown contaminants or combinatory toxic effects from mixtures of contaminants. Thus, biological effect data greatly contribute to establish more realistic exposure and risk-scenarios at contaminated sites. The work underlying this thesis presents possible techniques for high capacity screening for site-specific hazards at contaminated areas. By combining rapid water extractions and cell-based in vitro designs measures of the toxic potential in soils was obtained. Toxicologically bioavailable fractions of mixed metal pollution, including arsenic, were primarily investigated in this thesis. In two of the studies, environmental availability and toxicological bioavailability of arsenic was explored in CCA-contaminated soils. Application of cell-based in vitro screening techniques was also conducted at a metal contaminated industrial site to obtain spatial distribution of toxicity. Multivariate association techniques were employed in the interpretation of environmental exposure and cytotoxicity data. It was shown that cell-based in vitro systems for both basal cytotoxicity and specific end-points targeting arsenic could assess the toxic potential from extracts obtained by several water-based extraction techniques including Pressurised Liquid Extraction (PLE). The cell-based in vitro systems were found to add important information on the site-specific differences in arsenics genotoxic potential from CCA-contaminated soils. The results highlight the importance of taking speciation and toxicological bioavailability into account in the risk analysis, rather than to base risk estimates on total load of contaminants. The presented screening approach was successfully applied at a metal polluted industrial site where spatial distribution of toxicity was obtained. PLE extraction also provided means for combined toxicological and chemical screening of explosives in soils from live-fire training ranges. Multivariate association techniques highly facilitated the interpretation of complex environmental data. The PLE was found to be a rapid extraction technique that has sufficient environmental relevance to be used in environmental impact analyses. It was also concluded that other cell-based in vitro systems that target specific toxic effects have large potential for being used in screening for a variety of environmental chemicals. Keywords: Environmental availability, Environmental bioavailability, Toxicological bioavailability, mixture toxicity, hazard screening, contaminated soils, heavy metals, arsenic, CCA, explosives, soil extraction, water extracts, cell-based in vitro tests, cytotoxicity, genotoxicity, PLE, MVDA, PCA, PLS.
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| 34. |
- Rajaei, Hossein, et al.
(författare)
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Catalogue of the lepidoptera of Iran
- 2023
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Ingår i: Integrative Systematics. - : Stuttgart State Museum of Natural History. - 2628-2380. ; 6:SP1, s. 121-459
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Tidskriftsartikel (refereegranskat)
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| 35. |
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| 36. |
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| 37. |
- Ulfsdotter Turesson, Eva, et al.
(författare)
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Development and reproduction of the freshwater harpacticoid copepod Attheyella crassa for assessing sediment-associated toxicity
- 2007
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Ingår i: Aquatic Toxicology. - : Elsevier BV. - 0166-445X .- 1879-1514. ; 83:3, s. 180-9
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Tidskriftsartikel (refereegranskat)abstract
- Both freshwater and marine sediments are sinks for many anthropogenic substances. This may pose a risk to benthic and epibenthic organisms and it is crucial that toxicity tests that are available for environmental risk assessment can identify potentially adverse effects of sediment-associated substances on benthic organisms, such as harpacticoid copepods. While marine harpacticoids have been protected via a number of acute and chronic sediment tests, the freshwater harpacticoid copepod community has so far been neglected in such activities. The main aim of the present study was therefore to (a) find a suitable freshwater harpacticoid copepod, (b) establish robust laboratory mass cultures and (c) develop a chronic test for assessment of sediment-associated toxicity using spiked sediments. After several cultivation trials with a number of potential test species, the choice fell on the benthic freshwater harpacticoid copepod Attheyella crassa, a species that possesses many of the characteristic features identified as prerequisites for toxicity test organisms, e.g. it has a sexual reproduction, it is relatively easy to grow and keep in mass cultures in the laboratory, and it has a small body size. Owing to the relatively long generation time of freshwater harpacticoids (in relation to many marine harpacticoids), it was decided that the test should be separated into a development part (21 days) and a reproduction part (14 days) running in parallel. As a reference substance we used the fungicide tebuconazole, which is currently subject to risk assessment and which partitions to soil and sediment. Clear concentration-related responses were observed for all endpoints analyzed. Nauplia body length was the most sensitive endpoint with a measured time weighted LOEC(water) of 20microg/L. The corresponding LOEC(water) for larval mortality and offspring production was 65 and 62microg/L, respectively. In conclusion, A. crassa is an ecologically relevant test species for freshwater ecosystems and particularly for the cold, oligotrophic and often acidic lakes of Northern Europe. Regardless of the relatively long generation time of this species, our results clearly show that sediment-associated toxicity related to development and sexual reproduction can be assessed within 2-3 weeks exposure with the developed bioassay.
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| 38. |
- Wiklund, Ann-Kristin Eriksson, et al.
(författare)
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Sucralose - An ecotoxicological challenger?
- 2012
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Ingår i: Chemosphere. - : Elsevier BV. - 0045-6535 .- 1879-1298. ; 86:1, s. 50-55
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Tidskriftsartikel (refereegranskat)abstract
- The non-calorie sweetener sucralose - sucrose containing three chlorine atoms - is intensively sweet and has become a popular substitute for sugar. Its widespread use, exceptional stability in combination with high water solubility have thus resulted in contamination of recipient waters. Earlier studies on sucralose in aquatic organisms indicate low bioaccumulation potential and negligible acute/chronic toxicity, but the close structural resemblance with sucrose in combination with the importance of sugar in nature, warrant a more detailed ecotoxicological assessment. The aim of this investigation was therefore to study behavioural and physiological effects of sucralose in crustaceans. Our results show that both physiology and locomotion behaviour were affected by exposure to sucralose. In Daphnia magna, the behavioural response was manifested as altered swimming height and increased swimming speed, whereas in gammarids the time to reach food and shelter was prolonged. Regardless if these behavioural responses were initiated via traditional toxic mechanisms or stimulatory effects, they should be considered as a warning, since exposed organisms may diverge from normal behaviour, which ultimately can have ecological consequences.
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