The variable polarization undulator beamline UE52 SGM at BESSY II

UE52 SGM is an open port beamline with a monochromator containing 3 spherical gratings covering the energy range of 100 to 1500 eV and allows for variable polarization (circular and in any orientation linear) with a focus of about 20 - 60 μm (horizontal) x beamline slit (vertical) spot in focus

Web-based studies of lifestyle factors and immune function

Upper respiratory tract infection (URTI), is estimated to cost $40 billion per year in the US, not including the cost of influenza, and is the most common reason for seeking primary care in many countries. Despite this, little is known about how to decrease susceptibility. Lifestyle factors such as physical activity, stress, sleep, and diet are important modulators of immune function and in this thesis, five papers evaluating the use of Internet for data collection, and the association of lifestyle factors to URTI and immune function in blood, are described. In Paper I, the feasibility of using Web questionnaires compared with traditional paper questionnaires in a population-based setting was investigated. The use of interactive Web-based questionnaires resulted in lower initial response rate but similar total response-rates on follow-up questionnaires. Based on these findings, we conducted a population-based Web cohort study of 1509 Swedish men and women aged 20-60 with a follow-up period of four months (Papers II-IV). Participants reported a total of 1181 occurrences of URTI. In Paper II, results show that high levels of physical activity (≥55 MET-hours/d, MET, metabolic equivalent task) were associated with an 18% reduced risk of self-reporting URTI compared with low levels of physical activity (<45 MET-hours/d) (IRR 0.82, 95% CI 0.69-0.98). In addition, highly stressed people, particularly men, appeared to benefit more from physical activity than those reporting lower stress levels. When studying intake of antioxidants and URTI risk in Paper III, we found that a high intake of vitamin C from food (>200 mg/d) was associated with a 31% lower risk of URTI compared with a low intake (<100 mg/d) (IRR 0.69, 95% CI 0.49-0.98) among women. This association was not seen among men, who overall had a lower intake of vitamin C than women. In Paper IV, we assessed adherence to the Nordic Nutrition Recommendations (NNR) as a measure of an overall healthy diet. The NNR include recommendations on macronutrients (e.g. saturated fat), micronutrients (vitamins and minerals), fiber, sodium, alcohol, and physical activity. Good adherence versus poor adherence to the NNR was not associated with risk of URTI in this study. In Paper V the natural variations of sleep duration, stress, physical activity, leukocyte numbers, and their function was examined in 36 men and women, aged 20-54. Results show that short sleep duration (<7h) prior to blood draw was associated with a 49% higher T cell function (95% CI 7/109%) in response to phytohemagglutinin (PHA) and 30% lower natural killer cell activity (NKCA) (95% CI -46/-8%) compared with normal prior sleep (7-9h). Results also indicate that high general perceived stress was associated with a 39% higher T cell function in response to PHA (95% CI 0/94%), and that high general physical activity was associated with an increased number of B cells and T cells, but general physical activity was not clearly associated with immune cell function. In conclusion, we found that Web questionnaires can be useful for research purposes in populations with high proportion of Internet users, especially when multiple follow-ups are needed. Paper II and III conclude that lifestyle factors such as physical activity, stress, and diet are associated with risk of self-reported URTI. However, no association was seen between good adherence to the NNR and URTI, which may be explained by the fact that the participants were generally very well-nourished and with a limited variation in the NNR score (Paper IV). In Paper V, we found that lifestyle factors were related to immunological markers in blood. Natural short sleep duration was associated with lower NKCA, which might impair ability to fight infections

Locating Nests of Birds in Grasslands From a Mobile Tower Blind

Locating nests of grassland passerines can be difficult, labor intensive, and disruptive to birds and vegetation. We developed a mobile tower blind for observing adult bird behavior and used it to locate nests in a western Montana grassland. We compared nest-search efficiency of behavioral observations from the tower versus the ground. Nests of savannah sparrow (Passerculus samhvichensis) were found in a higher proportion of territories searched from the tower (13/16 = 82%) than from the ground (4113 = 3 1%). Average search time for each nest found was lower from the tower (44 min) than from the ground (127 min). Both were lower than when we used drags made of rope or cable and chain (411 min). but nests were found earlier in the nesting cycle when we used drags. Adult birds were agitated and reluctant to approach and reveal their nests whenever an unconcealed observer was present in or near their territory. In contrast, normal behavior resumed within a few minutes after an observer entered the tower, even when the tower blind was within 10m of the nest. Observing behavioral cues from a tower blind provides substantial advantages for locating nests of savannah sparrows and probably other grassland birds. but effectiveness of the approach likely varies among species and habitats

PRIC295, a Nuclear Receptor Coactivator, Identified from PPARα-Interacting Cofactor Complex

The peroxisome proliferator-activated receptor-α (PPARα) plays a key role in lipid metabolism and energy combustion. Chronic activation of PPARα in rodents leads to the development of hepatocellular carcinomas. The ability of PPARα to induce expression of its target genes depends on Mediator, an evolutionarily conserved complex of cofactors and, in particular, the subunit 1 (Med1) of this complex. Here, we report the identification and characterization of PPARα-interacting cofactor (PRIC)-295 (PRIC295), a novel coactivator protein, and show that it interacts with the Med1 and Med24 subunits of the Mediator complex. PRIC295 contains 10 LXXLL signature motifs that facilitate nuclear receptor binding and interacts with PPARα and five other members of the nuclear receptor superfamily in a ligand-dependent manner. PRIC295 enhances the transactivation function of PPARα, PPARγ, and ERα. These data demonstrate that PRIC295 interacts with nuclear receptors such as PPARα and functions as a transcription coactivator under in vitro conditions and may play an important role in mediating the effects in vivo as a member of the PRIC complex with Med1 and Med24

Quantitative evaluation of transient valence orbital occupations in a 3d transition metal complex as seen from the metal and ligand perspective

It is demonstrated for the case of photo excited ferrocyanide how time resolved soft X ray absorption spectroscopy in transmission geometry at the ligand K edge and metal L3 edge provides quantitatively equivalent valence electronic structure information, where signatures of photo oxidation are assessed locally at the metal as well as the ligand. This allows for a direct and independent quantification of the number of photo oxidized molecules at two soft X ray absorption edges highlighting the sensitivity of X ray absorption spectroscopy to the valence orbital occupation of 3d transition metal complexes throughout the soft X ray rang

Probing Solute Solvent Interactions of Transition Metal Complexes Using L Edge Absorption Spectroscopy

In order to tailor solution phase chemical reactions involving transition metal complexes, it is critical to understand how their valence electronic charge distributions are affected by the solution environment. Here, solute amp; 8722;solvent interactions of a solvatochromic mixed ligand iron complex were investigated using X ray absorption spectroscopy at the transition metal L2,3 edge. Due to the selectivity of the corresponding core excitations to the iron 3d orbitals, the method grants direct access to the valence electronic structure around the iron center and its response to interactions with the solvent environment. A linear increase of the total L2,3 edge absorption cross section as a function of the solvent Lewis acidity is revealed. The effect is caused by relative changes in different metal amp; 8722;ligand bonding channels, which preserve local charge densities while increasing the density of unoccupied states around the iron center. These conclusions are corroborated by a combination of molecular dynamics and spectrum simulations based on time dependent density functional theory. The simulations reproduce the spectral trends observed in the X ray but also optical absorption experiments. Our results underscore the importance of solute amp; 8722;solvent interactions when aiming for an accurate description of the valence electronic structure of solvated transition metal complexes and demonstrate how L2,3 edge absorption spectroscopy can aid in understanding the impact of the solution environment on intramolecular covalency and the electronic charge distributio

DNA-Induced Unfolding of the Thyroid Hormone Receptor a A/B Domain through Allostery

The A/B domains of nuclear receptors such as thyroid receptor a (TRa) are considered to be conformationally flexible and can potentially adopt multiple structural conformations. We used intrinsic tryptophan fluorescence quenching and circular dichroism spectroscopy to characterize the unfolding of this A/B domain upon DNA binding to the contiguous DNA binding domain (DBD). We propose that this allosteric change in A/B domain conformation can allow it to make the multiple interactions with distinct molecular factors of the transcriptional preinitiation complex. We further suggest that by influencing the affinity of the DBD for DNA, A/B domain can fine-tune the recognition of promotor DNA by TRa

Metal water covalency in the photo aquated ferrocyanide complex as seen by multi edge picosecond X ray absorption

In this work, we investigate the photo aquation reaction of the ferrocyanide anion with multi edge picosecond soft X ray spectroscopy. Combining the information of the iron L edge with nitrogen and oxygen K edges, we carry out a complete characterization of the bonding channels in the [Fe CN 5 H2O ]3 amp; 8722; photo product. We observe clear spectral signatures of covalent bonding between water and the metal, reflecting the mixing of the Fe dz2 orbital with the 3a1 and 4a1 orbitals of H2O. Additional fingerprints related to the symmetry reduction and the resulting loss in orbital degeneracy are also reported. The implications of the elucidated fingerprints in the context of future ultra fast experiments are also discusse