| 1. |
- Aad, G., et al.
(författare)
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The ATLAS Experiment at the CERN Large Hadron Collider
- 2008
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Ingår i: Journal of Instrumentation. - 1748-0221. ; 3:S08003
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Forskningsöversikt (refereegranskat)abstract
- The ATLAS detector as installed in its experimental cavern at point 1 at CERN is described in this paper. A brief overview of the expected performance of the detector when the Large Hadron Collider begins operation is also presented.
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| 2. |
- Wahlund, Jan Erik, et al.
(författare)
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On the amount of heavy molecular ions in Titan's ionosphere
- 2009
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Ingår i: Planetary and Space Science. - : Elsevier BV. - 0032-0633 .- 1873-5088. ; 57:14-15, s. 1857-1865
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Tidskriftsartikel (refereegranskat)abstract
- We present observational evidence that the ionosphere of Titan below an altitude of 1150 km is a significant source of heavy (> 100 amu) molecular organic species. This study is based on measurements by five instruments (RPWS/LP, RPWS/E, INMS, CAPS/ELS, CAPS/IBS) onboard the Cassini spacecraft during three flybys (T17, T18, T32) of Titan. The ionospheric peaks encountered at altitudes of 950-1300 km had densities in the range 900-3000 cm(-3). Below these peaks the number densities of heavy positively charged ions reached 100-2000 cm(-3) and approached 50-70% of the total ionospheric density with an increasing trend toward lowest measured altitudes. Simultaneously measured negatively charged ion densities were in the range 50-150 cm(-3). These results imply that similar to 10(5)similar to 10(6) heavy positively charged ions/m(3)/s are continuously recombining into heavy neutrals and supply the atmosphere of Titan. The ionosphere may in this way produce 0.1-1 Mt/yr of heavy organic compounds and is therefore a sizable source for aerosol formation. We also predict that Titan's ionosphere is dominated by heavy (> 100 amu) molecular ions below 950 km.
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| 3. |
- Akkerman, V., et al.
(författare)
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Flow-flame interaction in a closed chamber
- 2008
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Ingår i: Physics of Fluids. - : AIP Publishing. - 1070-6631 .- 1089-7666. ; 20:5, s. 21-
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Tidskriftsartikel (refereegranskat)abstract
- Numerous studies of flame interaction with a single vortex and recent simulations of burning in vortex arrays in open tubes demonstrated the same tendency for the turbulent burning rate proportional to U-rms lambda(2/3), where U-rms is the root-mean-square velocity and lambda is the vortex size. Here, it is demonstrated that this tendency is not universal for turbulent burning. Flame interaction with vortex arrays is investigated for the geometry of a closed burning chamber by using direct numerical simulations of the complete set of gas-dynamic combustion equations. Various initial conditions in the chamber are considered, including gas at rest and several systems of vortices of different intensities and sizes. It is found that the burning rate in a closed chamber (inverse burning time) depends strongly on the vortex intensity; at sufficiently high intensities it increases with U-rms approximately linearly in agreement with the above tendency. On the contrary, dependence of the burning rate on the vortex size is nonmonotonic and qualitatively different from the law lambda(2/3). It is shown that there is an optimal vortex size in a closed chamber, which provides the fastest total burning rate. In the present work, the optimal size is six times smaller than the chamber height.
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| 4. |
- Carlström, Mattias, et al.
(författare)
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SOD1-Deficiency Causes Salt-Sensitivity and Aggravates Hypertension in Hydronephrosis
- 2009
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Ingår i: American Journal of Physiology. Regulatory Integrative and Comparative Physiology. - : American Physiological Society. - 0363-6119 .- 1522-1490. ; 297:1, s. R82-R92
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Tidskriftsartikel (refereegranskat)abstract
- Background: Hydronephrosis causes renal dysfunction and salt-sensitive hypertension, which is associated with NO-deficiency and abnormal tubuloglomerular feedback (TGF) response. We investigated the role of oxidative stress for salt-sensitivity and for hypertension in hydronephrosis. Methods: Hydronephrosis was induced in SOD1-transgenic (SOD1-tg), SOD1-deficient (SOD1-ko) and wild-type mice and in rats. In mice, telemetric measurements were performed during normal (0.7% NaCl) and high sodium (4% NaCl) diets and with chronic Tempol supplementation. 8-iso-prostaglandin-F2alpha (F2-IsoPs) and protein excretion profiles and histology were investigated. The acute effects of Tempol on blood pressure and TGF were studied in rats. Results: In hydronephrosis, wild-type mice developed salt-sensitive hypertension (114+/-1 to 120+/-2 mmHg) which was augmented in SOD1-ko (125+/-3 to 135+/-4 mmHg), but abolished in SOD1-tg (109+/-3 to 108+/-3 mmHg). SOD1-ko controls displayed salt-sensitive blood pressure (108+/-1 to 115+/-2 mmHg), which was not found in wild-types or SOD1-tg. Chronic Tempol treatment reduced blood pressure in SOD1-ko controls (-7 mmHg) and in hydronephrotic wild-types (-8 mmHg) and SOD1-ko mice (-16 mmHg), but had no effect on blood pressure in wild-type or SOD1-tg controls. SOD1-ko controls and hydronephrotic wild-type and SOD1-ko mice exhibited increased fluid excretion associated with increased F2-IsoPs and protein excretion. The renal histopathological changes found in hydronephrotic wild-types were augmented in SOD1-ko and diminished in SOD-tg mice. Tempol attenuated blood pressure and normalized TGF response in hydronephrosis (DeltaPSF: 15.2+/-1.2 to 9.1+/-0.6 mmHg, TP: 14.3+/-0.8 to 19.7+/-1.4 nl/min). Conclusion: Oxidative stress due to SOD1-deficiency causes salt-sensitivity and plays a pivotal role for the development of hypertension in hydronephrosis. Increased superoxide formation may enhance TGF response and thereby contribute to hypertension.
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| 5. |
- Hamad, R. Rafik, et al.
(författare)
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Increased thrombin generation in women with a history of preeclampsia
- 2009
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Ingår i: Thrombosis Research. - : Elsevier BV. - 1879-2472 .- 0049-3848. ; 123:4, s. 580-586
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: Women with a history of preeclampsia have an increased risk for cardiovascular disease in later Life. We evaluated thrombogenic characteristics of women with a previous history of preeclampsia, expressed in levels of thrombin generation, number of micropartictes and related to menstrual cycle and endothelial function, measured as flow-mediated dilatation. Materials and methods: We included 18 primipara women with a history of preeclampsia and 17 healthy primipara controls, 15 (+/- 3) months after the index pregnancy. Thrombin generation was measured by tissue factor triggered assay, microparticle levels were measured by flow cytometry and the endothelial function was previously examined by measuring flow-mediated dilatation by high-resotution ultrasound, during follicular and luteal phases of the menstrual cycle. Results: Women with previous preeclampsia produced more total amount of thrombin as calculated from thrombin max, thrombin potential and max slope levels p<0.05, 0.01 and 0.01 respectively. Platelet derived microparticle levels were higher in women with a history of preeclampsia, p=0.07. Flow-mediated dilatation was significantly decreased in comparison to healthy controls (p<0.0001). There were no variation in levels of thrombin, microparticies and flow-mediated dilatation during the menstrual phases. Conclusion: Women with a history of preectampsia show signs of hypercoagutability as indicated by higher thrombin generation and higher platelet derived microparticle levels. Since these women were investigated more than one year after delivery, these results may be indicative of an increased risk of cardiovascular events later in life. (c) 2008 Elsevier Ltd. Alt rights reserved.
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| 6. |
- Carlström, Mattias, et al.
(författare)
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Angiogenesis inhibition causes hypertension and placental dysfunction in a rat model of preeclampsia
- 2009
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Ingår i: Journal of Hypertension. - 0263-6352 .- 1473-5598. ; 27:4, s. 829-837
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Tidskriftsartikel (refereegranskat)abstract
- Background Preeclampsia is a serious pregnancy complication, accompanied by increased maternal and fetal morbidity. Different models have been used to study preeclampsia, but none of these display all the key features of the disease. Method We investigated the effects on maternal blood pressure and fetal outcome exerted by the angiogenesis inhibitor Suramin (1100 mg/kg i.p.) during early placentation. Blood pressure and heart rate were measured continuously with telemetry in Sprague - Dawley rats of four experimental groups: nonpregnant controls, Suramin-treated nonpregnant rats, pregnant controls and pregnant Suramin-treated rats. Blood samples were collected before pregnancy and at gestational day 20 for analysis of renin and sFIt-1. The fetal and placental morphology were evaluated after caesarian section on gestational day 20. Results The blood pressure of the pregnant Suramin-treated rats successively increased during pregnancy and differed by 17 mmHg at gestational day 20 compared with the pregnant control rats. In the pregnant Suramin-treated rats group, the renin levels increased (+122%) and the sFIt-1 levels decreased (-58%) during pregnancy. The pregnant Suramin-treated fetuses and placentae were smaller (2.8 g and 0.51 g) than the pregnant controls rats' fetuses and placentae (3.5g and 0.56g). Resorptions tended to be higher in the pregnant Suramin-treated rat litters compared with the pregnant control rat litters (P = 0.08). The area of the maternal blood vessels in the mesometrial triangle was smaller in the pregnant Suramin-treated rats group than in the pregnant control rats group. Conclusion The inhibition of uterine angiogenesis increases maternal blood pressure and compromises fetal and placental development. Placental hypoxia and subsequent activation of the renin-angiotensin system may play an important role for the hypertension. J Hypertens 27:829-837 (C) 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins.
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| 7. |
- Carlström, Mattias, et al.
(författare)
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Nitric oxide deficiency and increased adenosine response of afferent arterioles in hydronephrotic mice with hypertension
- 2008
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Ingår i: Hypertension. - : American Heart Association. - 0194-911X .- 1524-4563. ; 51:5, s. 1386-1392
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Forskningsöversikt (refereegranskat)abstract
- Afferent arterioles were used to investigate the role of adenosine, angiotensin II, NO, and reactive oxygen species in the pathogenesis of increased tubuloglomerular feedback response in hydronephrosis. Hydronephrosis was induced in wild-type mice, superoxide dismutase-1 overexpressed mice (superoxide-dismutase-1 transgenic), and deficient mice (superoxide dismutase-1 knockout). Isotonic contractions in isolated perfused arterioles and mRNA expression of NO synthase isoforms, adenosine, and angiotensin II receptors were measured. In wild-type mice, N(G)-nitro-L-arginine methyl ester (L-NAME) did not change the basal arteriolar diameter of hydronephrotic kidneys (-6%) but reduced it in control (-12%) and contralateral arterioles (-43%). Angiotensin II mediated a weaker maximum contraction of hydronephrotic arterioles (-18%) than in control (-42%) and contralateral arterioles (-49%). The maximum adenosine-induced constriction was stronger in hydronephrotic (-19%) compared with control (-8%) and contralateral kidneys (+/-0%). The response to angiotensin II became stronger in the presence of adenosine in hydronephrotic kidneys and attenuated in contralateral arterioles. L-NAME increased angiotensin II responses of all of the groups but less in hydronephrotic kidneys. The mRNA expression of endothelial NO synthase and inducible NO synthase was upregulated in the hydronephrotic arterioles. No differences were found for adenosine or angiotensin II receptors. In superoxide dismutase-1 transgenic mice, strong but similar L-NAME response (-40%) was observed for all of the groups. This response was totally abolished in arterioles of hydronephrotic superoxide dismutase-1 knockout mice. In conclusion, hydronephrosis is associated with changes in the arteriolar reactivity of both hydronephrotic and contralateral kidneys. Increased oxidative stress, reduced NO availability, and stronger reactivity to adenosine of the hydronephrotic kidney may contribute to the enhanced tubuloglomerular feedback responsiveness in hydronephrosis and be involved in the development of hypertension.
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| 8. |
- Eriksson, Anders, et al.
(författare)
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RPC-LAP : The Rosetta Langmuir probe instrument
- 2007
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Ingår i: Space Science Reviews. - : Springer Science and Business Media LLC. - 0038-6308 .- 1572-9672. ; 128:04-jan, s. 729-744
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Forskningsöversikt (refereegranskat)abstract
- The Rosetta dual Langmuir probe instrument, LAP, utilizes the multiple powers of a pair of spherical Langmuir probes for measurements of basic plasma parameters with the aim of providing detailed knowledge of the outgassing, ionization, and subsequent plasma processes around the Rosetta target comet. The fundamental plasma properties to be studied are the plasma density, the electron temperature, and the plasma flow velocity. However, study of electric fields up to 8 kHz, plasma density fluctuations, spacecraft potential, integrated UV flux, and dust impacts is also possible. LAP is fully integrated in the Rosetta Plasma Consortium (RPC), the instruments of which together provide a comprehensive characterization of the cometary plasma.
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| 9. |
- Eriksson, Erik J., et al.
(författare)
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Acoustic impact on decoding of semantic emotions
- 2007
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Ingår i: Speaker classification II. - Berlin : Springer. - 9783540741213 ; , s. 57-69
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- This paper examines the interaction between the emotion indicated by the content of an utternance and the emotion indicated by the acoustic of an utterance, and considers whether a speaker can hide their emotional state by acting an emotion even though being semantically honest. Three female and two male speakers of Swedish were recorded saying the sentences “Jag har vunnit en miljon pa° lotto” (I have won a million on the lottery), “Det finns böcker i bokhyllan” (There are books on the bookshelf) and “Min mamma har just dött” (my mother just died) as if they were happy, neutral (indifferent), angry or sad. Thirty-nine experimental participants (19 female and 20 male) heard 60 randomly selected stimuli randomly coupled with the question “Do you consider this speaker to be emotionally X?”, where X could be angry, happy, neutral or sad. They were asked to respond yes or no; the listeners’ responses and reaction times were collected. The results show that semantic cues to emotion play little role in the decoding process. Only when there are few specific acoustic cues to an emotion do semantic cues come into play. However, longer reaction times for the stimuli containing mismatched acoustic and semantic cues indicate that the semantic cues to emotion are processed even if they impact little on the perceived emotion.
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| 10. |
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