Aspects of ethnicity on blood pressure regulating mechanisms and kidney function in a defined population

Background: Middle Eastern immigrants represent a growing population in Sweden today. This group are at higher risk for type 2 diabetes than the native population, but are also shown to exhibit unique properties; despite an abundance in traditional cardiometabolic risk factors such as obesity, dearranged blood lipids and diminished physical acitivity, this group seem to exhibit lower blood pressure levels. Further, people with type 2 diabetes of Middle Eastern descent have lower all cause and cardiovascular mortality rates, as compared to the native Swedish population. This indicates that Middle Eastern immmigrants may exhibit protective mechanisms towards cardiovascular diseases (CVD) that remain to be unravelled. Renal function is closely related to blood pressure. Further, new evidence on mechanisms in relation to blood pressure regulation and renal function has emerged, including vascular ageing, i.e. gradual change in the vascular structure and the endogenous opioid marker Pro-Enkephalin (PENK), which is shown to exhibit a direct cardiodepressive effect on the kidneys.Aims: The general aim was to study potential differences across ethnicities on renal function, blood pressure and its regulating mechanisms as well as characteristics on diabetes and its complications - all of them, strongly associated with CVD. In specific, the aims were to study the contributing role of ethnicity (born in Iraq or Sweden) in each paper on: Renal function and its association with blood pressure (paper I), diabetes traits and incidence in diabetic complications (paper II), the biomarker PENK and its association with renal function (paper III) and arterial stiffness as an indicator of vascular ageing (paper IV). In this paper the aim was further to validate eGFR equations across a Middle Eastern ethnicity. Methods: The thesis is based on data from three different cohorts comparing Iraqi and Swedish born subjects: the MEDIM study (paper I and III), a population-based cross-sectional study, conducted in 2010-2012. The study included physical examinations, blood sampling and collection of information on lifestyle, comorbidity and medication. The ANDIS study (paper II), a longitudinal follow-up study, recruiting patients diagnosed with diabetes during 2008-2016 and followed for complications until 2017. The MEDIM 2019 population-based study (paper IV), a cross-sectional study conducted in 2019-2020 assessing iohexol clearance for determining measured GFR (mGFR), pulse wave velocity (PWV) as measurement of arterial stiffness, physical examinations, blood sampling and information on comorbidity, lifestyle and medication.Results: In paper I, Iraqi-born immigrants (n=1214) exhibited a better renal function as described by higher levels of estimated GFR (eGFR) in comparison to the Swedish-born control group (n=659) (96.5 vs 93.6 mL/min/1.73m2, p=0.009). Further, the association between blood pressure and renal function was significantly weaker in the Iraqi group as confirmed by a signification interaction (Pinteractino = Country of birth x eGFRCAPA=0.004). In paper II, a larger proportion of Iraqi-born immigrants (n=183) had insulin-deficient diabetes in comparison to the Swedish-born control group (n=7044) (27.9 vs. 16.2%, p<0.001) and a lower proportion had insulin-resistant diabetes (5.5 vs. 16.3%, p<0.001). The risk for chronic kidney disease (CKD) among diabetes patients was lower in the Iraqi-born group (HR 0.26, 95% CI 0.08-0.8). In paper III, levels of PENK did not differ between Iraqi-born immigrants (n=1263) and the Swedish-born control group (n=680), despite higher eGFR in the Iraqi group. The association between PENK and renal function was weaker in the Iraqi group as supported by a significant interaction (Pinteractino = Country of birth x PENK=0.031). In paper IV, PWV did not differ between Iraqi-born immigrants (n=31) and the Swedish-born control group (n=32). When comparing mGFR to eGFR based on various equations, the commonly used CAPA equation was less accurate in the Iraqi group. The results indicated that the CKD-EPI equations could be accurate equations in the Iraqi group.Conclusion: Iraqi born immigrants had a more favorable renal function, an insulin deficient diabetes trait and considerably lower risk for diabetic kidney disease, than for the native Swedish population. The impact on renal function of blood pressure as well as of the cardiodepressive opioid PENK was weaker among Iraqi-born immigrants, which may contribute to a preserved renal function in the Iraqi-born group. In the long run, a more favorable renal function and less susceptible kidneys could serve as an important advantageous mechanism in the protection against CVD among Iraqi-born immigrants

Transition Probabilities Of Astrophysical Interest In The Niobium Ions Nb+ And Nb2+

Aims. We attempt to derive accurate transition probabilities for astrophysically interesting spectral lines of Nb II and Nb III and determine the niobium abundance in the Sun and metal-poor stars rich in neutron-capture elements. Methods. We used the time-resolved laser-induced fluorescence technique to measure radiative lifetimes in Nb II. Branching fractions were measured from spectra recorded using Fourier transform spectroscopy. The radiative lifetimes and the branching fractions were combined yielding transition probabilities. In addition, we calculated lifetimes and transition probablities in Nb II and Nb III using a relativistic Hartree-Fock method that includes core polarization. Abundances of the sun and five metal-poor stars were derived using synthetic spectra calculated with the MOOG code, including hyperfine broadening of the lines. Results. We present laboratory measurements of 17 radiative lifetimes in Nb II. By combining these lifetimes with branching fractions for lines depopulating the levels, we derive the transition probabilities of 107 Nb II lines from 4d(3)5p configuration in the wavelength region 2240-4700 angstrom. For the first time, we present theoretical transition probabilities of 76 Nb III transitions with wavelengths in the range 1430-3140 angstrom. The derived solar photospheric niobium abundance log epsilon(circle dot) = 1.44 +/- 0.06 is in agreement with the meteoritic value. The stellar Nb/Eu abundance ratio determined for five metal-poor stars confirms that the r-process is a dominant production method for the n-capture elements in these stars.Integrated Initiative of Infrastructure RII3-CT-2003-506350Swedish Research CouncilKnut and Alice Wallenberg FoundationBelgian FRS-FNRSFRIAUS National Science Foundation AST-0607708, AST-0908978Astronom

Repetitive DNA is associated with centromeric domains in Trypanosoma brucei but not Trypanosoma cruzi

Centromeres in Trypanosoma cruzi and Trypanosoma brucei can be localised to regions between directional gene clusters that contain degenerate retroelements, and in the case of T. brucei, repetitive DNA

Adult-onset diabetes in Middle Eastern immigrants to Sweden : Novel subgroups and diabetic complications-The All New Diabetes in Scania cohort diabetic complications and ethnicity

Background Middle Eastern immigrants to Europe represent a high risk population for type 2 diabetes. We compared prevalence of novel subgroups and assessed risk of diabetic macro- and microvascular complications between diabetes patients of Middle Eastern and European origin. Methods This study included newly diagnosed diabetes patients born in Sweden (N = 10641) or Iraq (N = 286), previously included in the All New Diabetes in Scania cohort. The study was conducted between January 2008 and August 2016. Patients were followed to April 2017. Incidence rates in diabetic macro- and microvascular complications were assessed using cox-regression adjusting for the confounding effect of age at onset, sex, anthropometrics, glomerular filtration rate (eGFR) and HbA1c. Findings In Iraqi immigrants versus native Swedes, severe insulin-deficient diabetes was almost twice as common (27.9 vs. 16.2% p <0.001) but severe insulin-resistant diabetes was less prevalent. Patients born in Iraq had higher risk of coronary events (hazard ratio [HR] 1.84, 95% CI 1.06-3.12) but considerably lower risk of chronic kidney disease (CKD) than Swedes (HR 0.19; 0.05-0.76). The lower risk in Iraqi immigrants was partially attributed to better eGFR. Genetic risk scores (GRS) showed more genetic variants associated with poor insulin secretion but lower risk of insulin resistance in the Iraqi than native Swedish group. Interpretation People with diabetes, born in the Middle East present with a more insulin-deficient phenotype and genotype than native Swedes. They have a higher risk of coronary events but lower risk of CKD. Ethnic differences should be considered in the preventive work towards diabetes and its complications.Peer reviewe

A deep search for planets in the inner 15 au around Vega

We present the results of a deep high-contrast imaging search for planets around Vega. Vega is an ideal target for high-contrast imaging because it is bright, nearby, and young with a face-on two-belt debris disk which may be shaped by unseen planets. We obtained $J-$ and $H-$band data on Vega with the coronagraphic integral-field spectrograph Project 1640 (P1640) at Palomar Observatory. Two nights of data were obtained in 2016, in poor seeing conditions, and two additional nights in more favorable conditions in 2017. In total, we obtained 5.5 hours of integration time on Vega in moderate to good seeing conditions (<1.5"). We did not detect any low mass companions in this system. Our data present the most sensitive contrast limits around Vega at very small separations (2-15 au) thus far, allowing us to place new constraints on the companions which may be sculpting the Vega system. In addition to new constraints, as the deepest data obtained with P1640, these observations form the final legacy of the now decommissioned instrument.Comment: Accepted for publication in A

A Library of Late Transition Metal Alloy Dielectric Functions for Nanophotonic Applications

Accurate complex dielectric functions are critical to accelerate the development of rationally designed metal alloy systems for nanophotonic applications, and to thereby unlock the potential of alloying for tailoring nanostructure optical properties. To date, however, accurate alloy dielectric functions are widely lacking. Here, a time-dependent density-functional theory computational framework is employed to compute a comprehensive binary alloy dielectric function library for the late transition metals most commonly employed in plasmonics (Ag, Au, Cu, Pd, Pt). Excellent agreement is found between electrodynamic simulations based on these dielectric functions and selected alloy systems experimentally scrutinized in 10 at% composition intervals. Furthermore, it is demonstrated that the dielectric functions can vary in very non-linear fashion with composition, which paves the way for non-trivial optical response optimization by tailoring material composition. The presented dielectric function library is thus a key resource for the development of alloy nanomaterials for applications in nanophotonics, optical sensors, and photocatalysis

Copper catalysis at operando conditions - bridging the gap between single nanoparticle probing and catalyst-bed-averaging

In catalysis, nanoparticles enable chemical transformations and their structural and chemical fingerprints control activity. To develop understanding of such fingerprints, methods studying catalysts at realistic conditions have proven instrumental. Normally, these methods either probe the catalyst bed with low spatial resolution, thereby averaging out single particle characteristics, or probe an extremely small fraction only, thereby effectively ignoring most of the catalyst. Here, we bridge the gap between these two extremes by introducing highly multiplexed single particle plasmonic nanoimaging of model catalyst beds comprising 1000 nanoparticles, which are integrated in a nanoreactor platform that enables online mass spectroscopy activity measurements. Using the example of CO oxidation over Cu, we reveal how highly local spatial variations in catalyst state dynamics are responsible for contradicting information about catalyst active phase found in the literature, and identify that both surface and bulk oxidation state of a Cu nanoparticle catalyst dynamically mediate its activity