42 research outputs found
On macrovascular and renal complications in type 1 diabetes : aspects on glycemic memory
No full textThere is a substantially increased risk of premature mortality and morbidity in cardiovascular disease (CVD) among type 1 diabetes individuals compared to individuals without diabetes. Development of microangiopathy and markers of macrovascular complications precedes these events. The SDIS and subsequent DCCT/EDIC trials conclusively established already in 1993 that early intensified insulin treatment halts microvascular complications. This has also been shown for macrovascular complications in the DCCT/EDIC trial, a finding suggested to be due to glycemic memory.In this thesis we first (Study I) aimed to investigate early signs of atherosclerosis, measured as carotid intima-media thickness (cIMT), and its relation to insulin sensitivity in young type 1 diabetes individuals.Then we compared (Study II) skin microvascular function in the foot and the time to first of hospitalization for ischemic foot ulcer in between the two groups in the SDIS cohort. We also investigated (Study III) long-term follow-up complications in the SDIS cohort, comparing incidence in all-cause mortality, mortality in CVD, as well as incidences in CVD events, i.e. myocardial infarction and stroke, and diabetic nephropathy, between patients earlier randomized for 7.5 years to intensive insulin treatment vs. standard treatment. Finally, we investigated (Study IV) long-term survival in individuals with type 1 diabetes, type 2 diabetes and without diabetes following coronary artery bypass grafting (CABG). In this study we combined the SWEDEHEART and the Swedish national diabetes registers. The outcome measures were all-cause mortality, mortality in CVD death and any major adverse coronary event, i.e. myocardial infarction, heart failure, stroke or need of revascularization.In study I, young type 1 diabetes individuals had an increased cIMT concomitant with insulin resistance compared to the non-diabetic group. In a multivariate analysis, insulin resistance was significantly associated to an increase in cIMT. In study II, 13 patients developed ischemic foot ulcer during the median 28 years of follow-up. Foot skin microcirculation blood flow was higher in the earlier intensively insulin-treated group compared with the standard treated group. Glycemic control measured as HbA1c levels was independently associated with endothelial-dependent vasodilatation and capsaicin-induced vasodilatation. In study III, during 28 years of follow-up 22 persons died. There was no significant difference between groups for all-cause mortality, mortality in myocardial infarction, stroke or ESRD, or for morbidity in myocardial infarction or stroke. One person in the ICT group compared with seven in the ST group developed ESRD. HbA1c did not differ between the two groups during the last 16 years of follow-up. In study IV, with a mean follow-up time of 5.9 years, a total of 6,765 out of 39,235 patients died: 17 % of whom had no diabetes, 21 % had type 1 diabetes, and 19 % had type 2 diabetes. The risk for all-cause mortality was doubled in type 1 diabetes, compared to type 2 diabetes. The risk of death was similar among type 1 diabetic men and women.Adolescents with type 1 diabetes show early signs of atherosclerosis compared to a matched control group. This was demonstrated together with insulin resistance. Earlier intensively insulin-treated type 1 individuals from the SDIS trial seem to have a favorable prognosis regarding the development of foot ulcers and diabetic nephropathy, compared to the standard treated individuals. This was demonstrated despite the same glycemic control for the last 16 years in the follow-up. Type 1 diabetes individuals have much poorer outcome after CABG intervention compared to type 2 diabetes individuals.List of scientific papersI. Rathsman B, Rosfors S, Sjöholm A, Nyström T. Early signs of atherosclerosis are associated with insulin resistance in non-obese adolescent and young adults with type 1 diabetes. Cardiovasc Diabetol. 2012 Nov 27;11:145 https://doi.org/10.1186/1475-2840-11-145 II. Rathsman B, Jensen-Urstad K, Nyström T. Intensified insulin treatment is associated with improvement in skin microcirculation and ischaemic foot ulcer in patients with type 1 diabetes mellitus: a long-term follow-up study. Diabetologia. 2014 Aug;57(8):1703-10 https://doi.org/10.1007/s00125-014-3248-2 III. Rathsman B, Donner M, Ursing C, and Nyström T. Intensified insulin treatment decreases the risk of end stage renal disease in type 1 diabetes: a long-term follow-up study. [Submitted]IV. Holzmann MJ, Rathsman B, Eliasson B, Kuhl J, Svensson AM, Nyström T, Sartipy U. Long-term Prognosis in Patients with Type 1 and Type 2 Diabetes Mellitus After Coronary Artery Bypass Grafting. J Am Coll Cardiol 2015;65:1644–52 https://doi.org/10.1016/j.jacc.2015.02.052 </p
Dagny : tidning för svenska kvinnorörelsen / (Årg. 3, N:r 33)
No full textNordiska skolmötet i Stockholm. Af A. S-m. 369
Svenska Hems nya lokaler. Af Elpis 371
Hvem är mördaren? Af A. K. 372
Kvinnoarbete och statsfinanser 373
Kvinnliga öfverlärare 373
Hedvig Charlotta Nordenflycht. Af Kerstin Rathsman 374
Rösträttsmötet i Stockholm för de nordiska skolkongressisterna 376
Notiser 377
Föreningsmeddelanden 37
SLAC-PUB-9801 hep-ph/9701300 Hints for Enhanced b → sg from Charm and Kaon Counting
No full textPreviously, motivation for enhanced b → sg from new flavor physics has centered on discrepancies between theory and experiment. Here two experimental hints are considered: (1) updated measurements of the charm multiplicity and B(B → Xc¯cs) at the Υ(4S) imply B(B → Xno charm) ≈ 12.4 ± 5.6%, (2) the B → K − X and B → K + /K − X branching fractions are in excess of conventional B → Xc → KX yields by about 16.9 ± 5.6% and 18 ± 5.3%, respectively. JETSET 7.4 was used to estimate kaon yields from s¯s popping in B → Xcūd decays. JETSET 7.4 Monte Carlos for B(B → Xsg) ∼ 15 % imply that the additional kaon production would lead to 1σ agreement with observed charged and neutral kaon yields. The Ks momentum spectrum would be consistent with recent CLEO bounds in the end point region. Search strategies for enhanced b → sg are discussed in light of large theoretical uncertainty in the standard model fast kaon background from b → s penguin operators. Work supported in part by Department of Energy Contract DE-AC03-76SF0051
Tests of models of color reconnection and a search for glueballs using gluon jets with a rapidity gap
No full textGluon jets with a mean energy of 22 GeV and purity of 95% are selected from hadronic Z0 decay events produced in e+e- annihilations. A subsample of these jets is identified which exhibits a large gap in the rapidity distribution of particles within the jet. After imposing the requirement of a rapidity gap, the gluon jet purity is 86%. These jets are observed to demonstrate a high degree of sensitivity to the presence of color reconnection, i.e. higher order QCD processes affecting the underlying color structure. We use our data to test three QCD models which include a simulation of color reconnection: one in the Ariadne Monte Carlo, one in the Herwig Monte Carlo, and the other by Rathsman in the Pythia Monte Carlo. We find the Rathsman and Ariadne color reconnection models can describe our gluon jet measurements only if very large values are used for the cutoff parameters which serve to terminate the parton showers, and that the description of inclusive Z0 data is significantly degraded in this case. We conclude that color reconnection as implemented by these two models is disfavored. The signal from the Herwig color reconnection model is less clear and we do not obtain a definite conclusion concerning this model. In a separate study, we follow recent theoretical suggestions and search for glueball-like objects in the leading part of the gluon jets. No clear evidence is observed for these objects.Gluon jets with a mean energy of 22 GeV and purity of 95% are selected from hadronic Z0 decay events produced in e+e- annihilations. A subsample of these jets is identified which exhibits a large gap in the rapidity distribution of particles within the jet. After imposing the requirement of a rapidity gap, the gluon jet purity is 86%. These jets are observed to demonstrate a high degree of sensitivity to the presence of color reconnection, i.e. higher order QCD processes affecting the underlying color structure. We use our data to test three QCD models which include a simulation of color reconnection: one in the Ariadne Monte Carlo, one in the Herwig Monte Carlo, and the other by Rathsman in the Pythia Monte Carlo. We find the Rathsman and Ariadne color reconnection models can describe our gluon jet measurements only if very large values are used for the cutoff parameters which serve to terminate the parton showers, and that the description of inclusive Z0 data is significantly degraded in this case. We conclude that color reconnection as implemented by these two models is disfavored. The signal from the Herwig color reconnection model is less clear and we do not obtain a definite conclusion concerning this model. In a separate study, we follow recent theoretical suggestions and search for glueball-like objects in the leading part of the gluon jets. No clear evidence is observed for these objects
Intensified insulin treatment is associated with improvement in skin microcirculation and ischaemic foot ulcer in patients with type 1 diabetes mellitus: a long-term follow-up study
No full textQCD evolution of jets in the quark–gluon plasma
No full textThe quark-gluon plasma (QGP) can be explored in relativistic heavy ion collisions by the jet quenching signature, i.e. by the energy loss of a high energy quark or gluon traversing the plasma. We introduce a novel QCD evolution formalism in the leading logarithm approximation, where normal parton radiation is interleaved with scattering on the plasma gluons occuring at a similar time scale. The idea is elaborated in two approaches. One extends the DGLAP evolution equations for fragmentation functions to include scatterings in the medium, which facilitates numerical solutions for comparison with data and provides a basis for a Monte Carlo implementation. The other approach is more general by including also the transverse momentum dependence of the jet evolution, which allows a separation of the scales also for the scattering term and provides a basis for analytical investigations. The two approaches are shown to be related and give the same characteristic softening of the jet depending on the temperature of the plasma. A substantial effect is found at the RHIC energy and is further enhanced at LHC. Systematic studies of data on the energy loss could, therefore, demonstrate the existence of the QGP and probe its properties.</p
Radiative B decay spectrum: DGE at NNLO.
No full textWe compute the differential ¯B → Xsγ decay width in the Standard Model as a
function of the photon energy using Dressed Gluon Exponentiation (DGE). The resummed
spectrum is matched with the fixed–order expansion, making use of the next–to–next–to–
leading order (NNLO) results for the matrix element of the magnetic dipole interaction O7
and NLO ones for other operators in the effective Weak Hamiltonian. We develop a new
technique to implement constraints on the analytic structure of the Sudakov factor in moment
space. This improves the behavior of the resummed spectrum away from the Sudakov
region. We also derive an analytic expression for the Borel transform of the perturbative
series for the O7 spectrum in the large–β0 limit. Using this example we demonstrate that
exponentiation in moment space is necessary for the calculation of the spectrum for E
>∼
2
GeV. Finally, we investigate numerically the relation between renormalons, power corrections
and support properties. We present predictions for the branching fraction and the
first few spectral moments as a function of a cut E
> E0 and estimate the theoretical
uncertainty
Parton Energy Loss Without Transverse Momentum Broadening
No full textThe JEWEL 1.0 Monte Carlo simulates jet evolution in a medium with a microscopic description of splitting and scattering processes. In the framework of this model we investigate the transverse momentum broadening due to medium effects in different scenarios. Depending on assumptions about hadronisation, we observe either a small increase or even a slight decrease of the mean transverse momentum, but no sizeable broadening. This appears to be a natural consequence of a model formulation which conserves energy and momentum microscopically at each splitting and at each scattering
A novel interplanetary communications relay
No full textA case study of a potential Earth-Mars interplanetary communications relay, designed to ensure continuous communications, is detailed. The relay makes use of orbits based on artificial equilibrium points via the application of continuous low thrust, which allows a spacecraft to hover above the orbital plane of Mars and thus ensure communications when the planet is occulted with respect to the Earth. The artificial equilibria of two different low-thrust propulsion technologies are considered: solar electric propulsion, and a solar sail/solar electric propulsion hybrid. In the latter case it is shown that the combination of sail and solar electric propulsion may prove advantageous, but only under specific circumstances of the relay architecture suggested. The study takes into account factors such as the spacecraft's power requirements and communications band utilized to determine the mission and system architecture. A detailed contingency analysis is considered for recovering the relay after increasing periods of spacecraft motor failure, and combined with a consideration for how best to deploy the relay spacecraft to maximise propellant reserves and mission duration
