The malleability of uranium: manipulating the charge-density wave in epitaxial films

We report x-ray synchrotron experiments on epitaxial films of uranium, deposited on niobium and tungsten seed layers. Despite similar lattice parameters for these refractory metals, the uranium epitaxial arrangements are different and the strains propagated along the a-axis of the uranium layers are of opposite sign. At low temperatures these changes in epitaxy result in dramatic modifications to the behavior of the charge-density wave in uranium. The differences are explained with the current theory for the electron-phonon coupling in the uranium lattice. Our results emphasize the intriguing possibilities of producing epitaxial films of elements that have complex structures like the light actinides uranium to plutonium.Comment: 6 pages, 6 figure

Simultaneous dynamic electrical and structural measurements of functional materials

A new materials characterization system developed at the XMaS beamline, located at the European Synchrotron Radiation Facility in France, is presented. We show that this new capability allows to measure the atomic structural evolution (crystallography) of piezoelectric materials whilst simultaneously measuring the overall strain characteristics and electrical response to dynamically (ac) applied external stimuli

Distinct order of Gd 4f and Fe 3d moments coexisting in GdFe4Al8

Single crystals of flux-grown tetragonal GdFe4Al8 were characterized by thermodynamic, transport, and x-ray resonant magnetic scattering measurements. In addition to antiferromagnetic order at TN ~ 155 K, two low-temperature transitions at T1 ~ 21 K and T2 ~ 27 K were identified. The Fe moments order at TN with an incommensurate propagation vector (tau,tau,0) with tau varying between 0.06 and 0.14 as a function of temperature, and maintain this order over the entire T<TN range. The Gd 4f moments order below T2 with a ferromagnetic component mainly out of plane. Below T1, the ferromagnetic components are confined to the crystallographic plane. Remarkably, at low temperatures the Fe moments maintain the same modulation as at high temperatures, but the Gd 4f moments apparently do not follow this modulation. The magnetic phase diagrams for fields applied in [110] and [001] direction are presented and possible magnetic structures are discussed.Comment: v2: 14 pages, 12 figures; PRB in prin

Antiferromagnetic order and domains in Sr3Ir2O7 probed by x-ray resonant scattering

This article reports a detailed x-ray resonant scattering study of the bilayer iridate compound, Sr3Ir2O7, at the Ir L2 and L3 edges. Resonant scattering at the Ir L3 edge has been used to determine that Sr3Ir2O7 is a long-range ordered antiferromagnet below TN 230K with an ordering wavevector, q=(1/2,1/2,0). The energy resonance at the L3 edge was found to be a factor of ~30 times larger than that at the L2. This remarkable effect has been seen in the single layer compound Sr2IrO4 and has been linked to the observation of a Jeff=1/2 spin-orbit insulator. Our result shows that despite the modified electronic structure of the bilayer compound, caused by the larger bandwidth, the effect of strong spin-orbit coupling on the resonant magnetic scattering persists. Using the programme SARAh, we have determined that the magnetic order consists of two domains with propagation vectors k1=(1/2,1/2,0) and k2=(1/2,-1/2,0), respectively. A raster measurement of a focussed x-ray beam across the surface of the sample yielded images of domains of the order of 100 microns size, with odd and even L components, respectively. Fully relativistic, monoelectronic calculations (FDMNES), using the Green's function technique for a muffin-tin potential have been employed to calculate the relative intensities of the L2,3 edge resonances, comparing the effects of including spin-orbit coupling and the Hubbard, U, term. A large L3 to L2 edge intensity ratio (~5) was found for calculations including spin-orbit coupling. Adding the Hubbard, U, term resulted in changes to the intensity ratio <5%.Comment: 9 pages, 9 figure

A DNA barcode reference library for Swiss butterflies and forester moths as a tool for species identification, systematics and conservation.

Butterfly monitoring and Red List programs in Switzerland rely on a combination of observations and collection records to document changes in species distributions through time. While most butterflies can be identified using morphology, some taxa remain challenging, making it difficult to accurately map their distributions and develop appropriate conservation measures. In this paper, we explore the use of the DNA barcode (a fragment of the mitochondrial gene COI) as a tool for the identification of Swiss butterflies and forester moths (Rhopalocera and Zygaenidae). We present a national DNA barcode reference library including 868 sequences representing 217 out of 224 resident species, or 96.9% of Swiss fauna. DNA barcodes were diagnostic for nearly 90% of Swiss species. The remaining 10% represent cases of para- and polyphyly likely involving introgression or incomplete lineage sorting among closely related taxa. We demonstrate that integrative taxonomic methods incorporating a combination of morphological and genetic techniques result in a rate of species identification of over 96% in females and over 98% in males, higher than either morphology or DNA barcodes alone. We explore the use of the DNA barcode for exploring boundaries among taxa, understanding the geographical distribution of cryptic diversity and evaluating the status of purportedly endemic taxa. Finally, we discuss how DNA barcodes may be used to improve field practices and ultimately enhance conservation strategies

A drop-in clinic for patients with poorly-controlled diabetes: a community pharmacy feasibility study

Background Preparatory work suggests that there may be a role for the pharmacist in managing sub-optimal medication adherence and dose titration of prescribed medicines in patients with type 2 diabetes. Patients have reported that they are receptive towards pharmacists becoming involved in their care providing that this is integrated into the care received from their medical practice. Objective To determine whether a community pharmacy diabetes drop-in clinic is feasible and acceptable to patients with poorly controlled type 2 diabetes. Setting Five community pharmacies in Norfolk, UK. Method Poorly controlled patients, as defined by a national General Practitioner incentive scheme, were invited to participate in the study by a letter posted by their medical practice. One four-hour, pharmacist clinic, where participants were able to "drop-in", was conducted in five pharmacies every week for four to six weeks. Questionnaires before and after the consultation were used to determine the clinic's effect on satisfaction with, and beliefs about, medicines and adherence along with participant satisfaction. Pharmacists had the opportunity to provide feedback via "debrief" interviews. Main outcome measure As a feasibility study, a combination of outcomes were explored including informationsatisfaction and adherence. Results Thirty-three (9.6%) of the 342 patients with type 2 diabetes posted letters were recruited from four pharmacies. Follow-up questionnaire completion rate was 88%. The clinic demonstrated little change in the parameters measured over three months. All of the participants rated their general impression of the service as good or very good and all would be happy to recommend the service to others with diabetes. Sixteen participants (59%) stated that it would make them more likely to consult their pharmacist in the future. Pharmacists enjoyed providing the service as it allowed them to interact more formally, and for longer, with patients. Conclusion This research has demonstrated that a community pharmacy drop-in clinic is feasible and likely to be acceptable to both patients and pharmacists; however, cost effectiveness of such a service should be explored in future studies. Further thought should also be given to how this service can complement that provided by a nurse in the medical practice and how the pharmacist can provide additional benefit to the NHS

Magnetic structure of GdAgSb2 determined by x-ray resonant exchange scattering

X-ray resonant exchange-scattering experiments were performed on a single crystal of GdAgSb2 to determine the magnetic structure. Long-range antiferromagnetic ordering, characterized by a wave vector of (tau) over right arrow= (1/2 00), develops below the Neel temperature (T-N=13 K), consistent with the dc susceptibility measurements. For the scattering geometry employed in these measurements, the resonant enhancement at the (1/2 08) magnetic peak arises from electric quadrupole transitions only while the resonant enhancement at the (0-1/2 8) magnetic peak arises from electric dipole transitions. Q-dependent integrated intensity measurements were carried out, along with polarization analysis of the scattered beam, and demonstrated that the moments lie in the tetragonal basal plane and are perpendicular to the magnetic wave vector.This article is published as Song, C., W. Good, D. Wermeille, A. I. Goldman, S. L. Bud’ko, and P. C. Canfield. "Magnetic structure of GdAgSb 2 determined by x-ray resonant exchange scattering." Physical Review B 65, no. 17 (2002): 172415. DOI: 10.1103/PhysRevB.65.172415. Copyright 2002 American Physical Society. Posted with permission

Lactitol: gastrointestinal absorption and effect on blood lactate in healthy volunteers and patients with cirrhosis.

The gastrointestinal absorption of lactitol has been studied in 6 healthy volunteers and 8 patients with cirrhosis. Following administration of lactitol 0.5 g/kg, no lactitol was found in serum. The urinary excretion of lactitol over 24 h ranged from 0.1 to 1.4% of the administered dose (0.46% in cirrhotics and 0.35% in healthy volunteers). Blood D- and L-lactate and plasma glucose did not increase following lactitol. The data indicate that lactitol was poorly absorbed from the gastrointestinal tract in healthy volunteers and patients with cirrhosis, and that the disaccharide did not disturb glucose or lactate homeostasis