The contributions of enchytraeids and earthworms to the soil mineralization process in soils with fungicide.

Pesticides may harm soil organisms such as earthworms and enchytraeids, but knowledge is lacking on their relative sensitivity to these chemicals and the consequences on soil functions. The aim of this study was to assess the impact of exposure to a commercial fungicide formulation (Swing® Gold, containing dimoxystrobin and epoxiconazole) on the function of earthworms (Aporrectodea caliginosa) and enchytraeids (Enchytraeus buchholzi) in soil organic matter (SOM) mineralization. The soil organisms were incubated alone and together in a 26-day laboratory experiment. At the recommended field rate, the fungicide induced a decrease in the SOM mineralization and a delay in the maximum daily CO2 emissions compared to the control soil without fungicide. Soil fauna also influenced SOM mineralization with a higher cumulated CO2 release after 26 days in the control soil with earthworms (by 21%) than without fauna. When both earthworms and enchytraeids were present, SOM mineralization did not increase, and there was a negative effect on earthworm weight gain. Finally, an alteration of fauna influence with treatment was observed from day 19, meaning that the effect of fauna on SOM mineralization changed with fungicide treatment. Earthworms no longer promoted SOM mineralization when fungicide was present at three-fold the recommended field rate. The effects of enchytraeids on SOM mineralization were similar with and without fungicide exposure. This study underlines the importance of considering the relative sensitivity of soil organisms to environmental factors and interactions between them when assessing soil functioning.

Identification of Au-S complexes on Au(100).

Using a combination of scanning tunneling microscopy and density functional theory (DFT) calculations, we have identified a set of related Au-S complexes that form on Au(100), when sulfur adsorbs and lifts the hexagonal surface reconstruction. The predominant complex is diamond-shaped with stoichiometry Au4S5. All of the complexes can be regarded as combinations of S-Au-S subunits. The complexes exist within, or at the edges of, p(2 × 2) sulfur islands that cover the unreconstructed Au regions, and are observed throughout the range of S coverage examined in this study, 0.009 to 0.12 monolayers. A qualitative model is developed which incorporates competitive formation of complexes, Au rafts, and p(2 × 2) sulfur islands, as Au atoms are released by the surface structure transformation.

[Contract Conditions for GPs in Training while Working in Ambulatory Care]. / Vertragsbedingungen von ambulant tätigen Ärzten in Weiterbildung zum Facharzt für Allgemeinmedizin.

BACKGROUND: In Germany, the situation of GPs in training has received growing attention. Central funding of GPs in training who are working in ambulatory care has been increased up to 3 500 Euros/month. However, the contract conditions of GPs in training who are working in ambulatory care have been unknown as yet. METHODS: An online survey was undertaken. We recruited GPs in training by snowball sampling making use of national and local organisations of GPs and GPs in training. Our questionnaire consisted of questions concerning sociodemographic variables, gross wage, working hours, holidays and free days for educational purposes. Data were analysed by descriptive statistical methods. RESULTS: 152 participants fulfilled the inclusion criteria. 127 were full time GPs in training. The median of gross wage was 3 500 Euros/month, the mean gross wage was 3 878 Euros/month. The gross wage per hour was lower than that for GPs in training who are working in hospitals. Especially part time GPs in training had a lower gross wage per hour. One third of the GPs in training had no free days for educational purposes. More than half of the GPs in training had a weekly meeting with their supervisor, however, more than one third of GPs in training had no or only irregular meetings with their supervisor. CONCLUSIONS: In Germany, GPs in training earn in ambulatory care less than in hospital care. They do not have sufficient free days for educational purposes and often there is a lack of supervision. This seems to indicate that GPs in training are mainly considered as cheap coworkers instead of trainees.

Reconstruction of steps on the Cu(111) surface induced by sulfur.

A rich menagerie of structures is identified at 5 K following adsorption of low coverages (≤0.05 monolayers) of S on Cu(111) at room temperature. This paper emphasizes the reconstructions at the steps. The A-type close-packed step has 1 row of S atoms along its lower edge, where S atoms occupy alternating pseudo-fourfold-hollow (p4fh) sites. Additionally, there are 2 rows of S atoms of equal density on the upper edge, bridging a row of extra Cu atoms, together creating an extended chain. The B-type close-packed step exhibits an even more complex reconstruction, in which triangle-shaped groups of Cu atoms shift out of their original sites and form a base for S adsorption at (mostly) 4fh sites. We propose a mechanism by which these triangles could generate Cu-S complexes and short chains like those observed on the terraces.

Self-organization of S adatoms on Au(111): √3R30° rows at low coverage.

Using scanning tunneling microscopy, we observe an adlayer structure that is dominated by short rows of S atoms, on unreconstructed regions of a Au(111) surface. This structure forms upon adsorption of low S coverage (less than 0.1 monolayer) on a fully reconstructed clean surface at 300 K, then cooling to 5 K for observation. The rows adopt one of three orientations that are rotated by 30° from the close-packed directions of the Au(111) substrate, and adjacent S atoms in the rows are separated by √3 times the surface lattice constant, a. Monte Carlo simulations are performed on lattice-gas models, derived using a limited cluster expansion based on density functional theory energetics. Models which include long-range pairwise interactions (extending to 5a), plus selected trio interactions, successfully reproduce the linear rows of S atoms at reasonable temperatures.

Nonclassical "explosive" nucleation in Pb/Si(111) at low temperatures.

Classically, the onset of nucleation is defined in terms of a critical cluster of the condensed phase, which forms from the gradual aggregation of randomly diffusing adatoms. Experiments in Pb/Si(111) at low temperature have discovered a dramatically different type of nucleation, with perfect crystalline islands emerging "explosively" out of the compressed wetting layer after a critical coverage Θ_{c}=1.22 ML is reached. The unexpectedly high island growth rates, the directional correlations in the growth of neighboring islands and the persistence in time of where mass is added in individual islands, suggest that nucleation is a result of the highly coherent motion of the wetting layer, over mesoscopic distances.

Towards a high thermoelectric performance in rare-earth substituted SrTiO3: effects provided by strongly-reducing sintering conditions.

Donor-substituted strontium titanate ceramics demonstrate one of the most promising performances among n-type oxide thermoelectrics. Here we report a marked improvement of the thermoelectric properties in rare-earth substituted titanates Sr0.9R0.1TiO3±Î´ (R = La, Ce, Pr, Nd, Sm, Gd, Dy, Y) to achieve maximal ZT values of as high as 0.42 at 1190 K < T < 1225 K, prepared via a conventional solid state route followed by sintering under strongly reducing conditions (10%H2-90%N2, 1773 K). As a result of complex defect chemistry, both electrical and thermal properties were found to be dependent on the nature of the rare-earth cation and exhibit an apparent correlation with the unit cell size. High power factors of 1350-1550 µW m(-1) K(-2) at 400-550 K were observed for R = Nd, Sm, Pr and Y, being among the largest reported so far for n-type conducting bulk-ceramic SrTiO3-based materials. Attractive ZT values at high temperatures arise primarily from low thermal conductivity, which, in turn, stem from effective phonon scattering in oxygen-deficient perovskite layers formed upon reduction. The results suggest that highly-reducing conditions are essential and should be employed, whenever possible, in other related micro/nanostructural engineering approaches to suppress the thermal conductivity in target titanate-based ceramics.

Self-assembly of metal nanostructures on binary alloy surfaces.

Deposition of metals on binary alloy surfaces offers new possibilities for guiding the formation of functional metal nanostructures. This idea is explored with scanning tunneling microscopy studies and atomistic-level analysis and modeling of nonequilibrium island formation. For Au/NiAl(110), complex monolayer structures are found and compared with the simple fcc(110) bilayer structure recently observed for Ag/NiAl(110). We also consider a more complex codeposition system, (Ni + Al)/NiAl(110), which offers the opportunity for fundamental studies of self-growth of alloys including deviations for equilibrium ordering. A general multisite lattice-gas model framework enables analysis of structure selection and morphological evolution in these systems.

Rabies vaccinations: are abbreviated intradermal schedules the future?

Rabies is a deadly disease, and current preexposure vaccination schedules are lengthy and expensive. We identified nine studies investigating abbreviated schedules. Although initial responses were lower, accelerated adequate immune responses were elicited after booster vaccinations. Lower-dose (and therefore cheaper) vaccination schedules may constitute a valid alternative to current vaccination schedules.

The tropics and the crime they did not commit.

Travellers to tropical destinations who seek medical attention after returning to their home country often present with fever, frequently as a result of an imported infectious disease. For this reason, clinicians initially focus on an infectious cause when a clear relationship in time exists between travel and disease onset. We present a case of a patient, who developed fever 2 weeks after his return from Ghana and who was finally diagnosed with an auto-immune disease: arteritis of the large arteries. This case illustrates that broad differential diagnostic thinking is paramount in the assessment of returned travellers.

Communication: Structure, formation, and equilibration of ensembles of Ag-S complexes on an Ag surface.

We have utilized conditions of very low temperature (4.7 K) and very low sulfur coverage to isolate and identify Ag-S complexes that exist on the Ag(111) surface. The experimental conditions are such that the complexes form at temperatures above the temperature of observation. These complexes can be regarded as polymeric chains of varying length, with an Ag4S pyramid at the core of each monomeric unit. Steps may catalyze the formation of the chains and this mechanism may be reflected in the chain length distribution.

First case of Echinococcus vogeli infection imported to the Netherlands, January 2013.

In January 2013 in the Netherlands, a man in his 50s from Suriname underwent hemihepatectomy because of a cystic liver mass, assumed to be a cystadenoma. Pathology revealed an echinococcal infection. PCR analysis of cyst material identified Echinococcus vogeli, causing polycystic hydatid disease. This echinococcus species is rarely diagnosed outside South America. The patient received adequate treatment, but this case emphasises the importance of awareness of this infection when treating patients with cystic tumours from endemic areas.

Imported leishmaniasis in the Netherlands from 2005 to 2012: epidemiology, diagnostic techniques and sequence-based species typing from 195 patients.

Leishmaniasis is an imported disease in the Netherlands. We report data for the period between 2005 and 2012, on clinical presentation, country where leishmaniasis was acquired, and causative species, for 195 civilian and military patients who had travelled abroad. Most patients were affected by cutaneous leishmaniasis (CL) (n=185 patients), while visceral leishmaniasis (VL) (n=8 patients) and mucocutaneous leishmaniasis (n=2 patients) were less frequently observed. All VL patients had been infected in Europe. CL was mainly acquired in Afghanistan, Surinam, Morocco and Spain. The majority of CL patients consisted of military personnel (55%, 102/185), 78 of whom had been infected during an outbreak in Afghanistan. Parasitological diagnosis was made by a combination of polymerase chain reaction (PCR), microscopy and culture. Compared to a standard of parasitological proof by any method other than the one under consideration, sensitivities of the individual methods ranged from 73% to 98%. Microscopy was least sensitive, but is fast and cheap. Mini-exon repeat PCR combines high sensitivity and specificity, and allows differentiation between species by sequencing of the PCR product. Eight different species or species complexes were identified, allowing species-specific therapy. Four patients proved infected with Leishmania naiffi, a hitherto rarely described cause of leishmaniasis. In comparison to previous decennia, an increase in cutaneous leishmaniasis was observed in our hospital, both in civilian and military patients who had travelled abroad. This calls for increased awareness among clinicians, availability of diagnostic tests and species-specific treatment guidelines in non-endemic countries.

High island densities and long range repulsive interactions: Fe on epitaxial graphene.

The understanding of metal nucleation on graphene is essential for promising future applications, especially of magnetic metals which can be used in spintronics or computer storage media. A common method to study the grown morphology is to measure the nucleated island density n as a function of growth parameters. Surprisingly, the growth of Fe on graphene is found to be unusual because it does not follow classical nucleation: n is unexpectedtly high, it increases continuously with the deposited amount θ and shows no temperature dependence. These unusual results indicate the presence of long range repulsive interactions. Kinetic Monte Carlo simulations and density functional theory calculations support this conclusion. In addition to answering an outstanding question in epitaxial growth, i.e., to find systems where long range interactions are present, the high density of magnetic islands, tunable with θ, is of interest for nanomagnetism applications.

Nanodomains due to phason defects at a quasicrystal surface.

Among the three coexisting types of terraces found on the twofold surface of the d-Al-Cu-Co quasicrystal, nanodomains are essentially observed on the transition-metal rich ones, with a coherent interface boundary. Both clean surface and Ag growth analyses, demonstrate that nanodomain surfaces are structurally identical to one of the two other terraces, which contains 85 at. % Al. We provide evidence that the nanodomains are a manifestation of phason defects that extend downward toward the bulk, and state that nanodomains develop because the energetic cost of creating the phason is outweighed by the change in surface energy. Consequently, the formation of nanodomains involves more than just the surface layer, but is driven by surface energetics.

Temperature-dependent growth shapes of Ni nanoclusters on NiAl(110).

Scanning tunneling microscopy studies reveal that two-dimensional nanoscale Ni islands formed by deposition of Ni on NiAl(110) between 200-400 K exhibit far-from-equilibrium growth shapes which change systematically with temperature. Island structure reflects the two types of adsorption sites available for Ni adatoms, and island shapes are controlled by the details of adatom diffusion along island edges accounting for numerous local configurations. The temperature dependence of the island shapes is captured and elucidated by kinetic Monte Carlo simulation of a realistic atomistic-level multisite lattice-gas model incorporating precise diffusion barriers. These barriers are obtained by utilizing density functional theory to probe energetics not just at adsorption sites but also at transition states for diffusion. This success demonstrates a capability for predictive atomistic-level modeling of nanocluster formation and shape selection in systems that have a high level of energetic and kinetic complexity.

Miltefosine treatment of Leishmania major infection: an observational study involving Dutch military personnel returning from northern Afghanistan.

In a retrospective, observational study involving 34 patients with Leishmania major infection, 31 of whom had experienced unsuccessful treatment with intralesional antimony (ilSb(v)), miltefosine proved effective. Thirty patients experienced cure after receipt of miltefosine, 3 after receipt of additional ilSb(v), and 1 after 28 daily intravenous injections of antimony. Temporary diminution of ejaculate volume was reported by 21 patients.

Low-temperature adsorption of H2S on Ag(111).

H(2)S forms a rich variety of structures on Ag(111) at low temperature and submonolayer coverage. The molecules decorate step edges, exist as isolated entities on terraces, and aggregate into clusters and islands, under various conditions. One type of island exhibits a (√37×√37)R25.3° unit cell. Typically, molecules in the clusters and islands are separated by about 0.4 nm, the same as the S-S separation in crystalline H(2)S. Density functional theory indicates that hydrogen-bonded clusters contain two types of molecules. One is very similar to an isolated adsorbed H(2)S molecule, with both S-H bonds nearly parallel to the surface. The other has a S-H bond pointed toward the surface. The potential energy surface for adsorption and diffusion is very smooth.

High Layer Uniformity of Two-Dimensional Materials Demonstrated Surprisingly from Broad Features in Surface Electron Diffraction.

Paradoxically, a very broad diffraction background, named the bell-shaped-component (BSC), has been established as a feature of graphene growth. Recent diffraction studies as a function of electron energy have shown that the BSC is not related to scattering interference. Here, additional experiments are carried out as a function of temperature over the range in which single-layer graphene (SLG) grows. Quantitative fitting of the profiles shows that the BSC follows the increase of the Gr(10) spot, proving directly that the BSC indicates high-quality graphene. Additional metal deposition experiments provide more information about the BSC. The BSC is insensitive to metal deposition, and it increases with metal intercalation, because a more uniform interface forms between graphene and SiC. These experiments support the conclusion that the BSC originates from electron confinement within SLG, and surprisingly, it is an excellent measure of graphene uniformity.

Accelerated coarsening of Ag adatom islands on Ag(111) due to trace amounts of S: mass-transport mediated by Ag-S complexes.

Scanning tunneling microscopy studies reveal that trace amounts of adsorbed S below a critical coverage on the order of 10 mML have little effect on the coarsening and decay of monolayer Ag adatom islands on Ag(111) at 300 K. In contrast, above this critical coverage, decay is greatly accelerated. This critical value appears to be determined by whether all S can be accommodated at step edges. Accelerated coarsening derives from the feature that the excess S (above that incorporated at steps) produces significant populations on the terraces of metal-sulfur complexes, which are stabilized by strong Ag-S bonding. These include AgS(2), Ag(2)S(2), Ag(2)S(3), and Ag(3)S(3). Such complexes are sufficiently populous and mobile that they can potentially lead to greatly enhanced metal mass transport across the surface. This picture is supported by density functional theory analysis of the relevant energetics, as well as by reaction-diffusion equation modeling to assess the mechanism and degree of enhanced coarsening.