Permanent deactivation of boron-oxygen-related recombination centres in crystalline silicon

[no abstract

Charge density wave and charge pump of interacting fermions in circularly shaken hexagonal optical lattices

We analyze strong correlation effects and topological properties of interacting fermions with a Falicov-Kimball type interaction in circularly shaken hexagonal optical lattices, which can be effectively described by the Haldane-Falicov-Kimball model, using the real-space Floquet dynamical mean-field theory (DMFT). The Haldane model, a paradigmatic model of the Chern insulator, is experimentally relevant, because it has been realized using circularly shaken hexagonal optical lattices. We show that in the presence of staggering a charge density wave emerges, which is affected by interactions and resonant tunneling. We demonstrate that interactions smear out the edge states by introducing a finite life time of quasiparticles. Even though a general method for calculating the topological invariant of a nonequilibrium steady state is lacking, we extract the topological invariant using a Laughlin charge pump set-up. We find and attribute to the dissipations into the bath connected to every lattice site, which is intrinsic to real-space Floquet DMFT methods, that the pumped charge is not an integer even for the non-interacting case at very low reservoir temperatures. Furthermore, using the rate equation based on the Floquet-Born-Markov approximation, we calculate the charge pump from the rate equations for the non-interacting case to identify the role of the spectral properties of the bath. Starting from this approach we propose an experimental protocol for measuring quantized charge pumping.Comment: 13 pages, 12 figures, published versio

Stability of the hard and soft tissue profile after mandibular advancement in sagittal split osteotomies: a longitudinal and long-term follow-up study

The aim of the study was to conduct a long-term follow-up investigation of the stability of hard and soft tissues after bilateral sagittal split osteotomy (BSSO) with rigid internal (RIF) fixation to advance the mandible. Sixteen consecutive patients (12 females and 4 males, mean age 21.4 years) were available for re-examination 12.7 years (T5) after surgery. The preceding follow-ups were before (T1), and 5 days (T2), 7.3 months (T3), and 13.9 months (T4) after surgery. Lateral cephalograms were traced by hand, digitized, and evaluated with the Dentofacial Planner® program. The x-axis for the system of co-ordinates ran through sella (point zero) and the line NSL -7 degrees. Thus, the program determined the x- and y-values of each variable and the usual angles and distances. Statistical analysis was carried out using Wilcoxon's matched-pair signed-ranks test with Bonferroni adjustments. The relationships between the examined variables were analysed by Spearman rank correlation coefficients. The backward relapse at point B (T5) was 2.42 mm, or 50 per cent, and at pogonion 3.21 mm, or 60 per cent of the initial advancement. The mean net effect at T5 on the labial fold (soft tissue point B) was 94 per cent of the advancement at point B. For the soft tissue chin (soft tissue pogonion), it was 119 per cent of the advancement at pogonion. The net effect on the lower lip (labrale inferior) was 55 per cent of the advancement at incision inferior. The amount of the surgical advancement of the mandible was correlated with the long-term relapse in point B. Among possible reasons for this relapse are the initial soft tissue profile, the initial growth direction, and the remodelling processes of the hard tissu

Stability of hard tissue profile after mandibular setback in sagittal split osteotomies: a longitudinal and long-term follow-up study

The aim of the study was to conduct a long-term follow-up on the stability of the hard tissues after bilateral sagittal split osteotomy (BSSO) with rigid internal fixation (RIF)to set back the mandible and to compare it with that of mandibular advancement performed by the same team of surgeons and with the same examination protocol. Seventeen consecutive patients (6 females and 11 males) could be re-examined 12.7 years (T5) after surgery. The previous examinations were before surgery (T1), 5 days (T2), and 6.6 (T3) and 14.4 (T4) months after surgery. Lateral cephalograms were traced by hand, digitized, and evaluated with the Dentofacial Planner® software program. The x-axis for the system of co-ordinates ran through sella (point zero) and the line nasion-sella-line minus 7 degrees. The program determined the x- and y-values of each variable and the usual angles and distances. The effects of treatment were determined with Wilcoxon matched pairs, signed ranks test, with Bonferroni adjustment, and the relationship between variables with Spearman rank correlation coefficient. Relapse at point B was 0.94 mm or 15 per cent and at pogonion 1.46 mm or 21 per cent of the initial setback at T5. Relapse was mainly short-term (T4-T2), 13 per cent for point B and 17 per cent for pogonion. Gender correlated significantly with relapse (T5-T2) at point B (P = 0.002) and pogonion (P = 0.021), i.e. females in contrast to males showed further distalization of the mandible instead of relapse. No correlations were seen for age or the amount of surgical setback. The long-term results in mandibular setback patients were more stable when compared with the mandibular advancement patients examined previously. The initial soft tissue profile, the initial growth direction, and the remodelling processes of the hard tissues must be considered as reasons for long-term relapse. Growth direction positively influenced the long-term results in females: further distalization of the mandible occurre

Shear-Stress Partitioning in Live Plant Canopies and Modifications to Raupach's Model

The spatial peak surface shear stress $${\tau _S^{\prime\prime}}$$ on the ground beneath vegetation canopies is responsible for the onset of particle entrainment and its precise and accurate prediction is essential when modelling soil, snow or sand erosion. This study investigates shear-stress partitioning, i.e. the fraction of the total fluid stress on the entire canopy that acts directly on the surface, for live vegetation canopies (plant species: Lolium perenne) using measurements in a controlled wind-tunnel environment. Rigid, non-porous wooden blocks instead of the plants were additionally tested for the purpose of comparison since previous wind-tunnel studies used exclusively artificial plant imitations for their experiments on shear-stress partitioning. The drag partitioning model presented by Raupach (Boundary-Layer Meteorol 60:375-395, 1992) and Raupach etal. (J Geophys Res 98:3023-3029, 1993), which allows the prediction of the total shear stress τ on the entire canopy as well as the peak $${(\tau _S ^{\prime\prime}/\tau )^{1/2}}$$ and the average $${(\tau _S^{\prime}/\tau )^{1/2}}$$ shear-stress ratios, is tested against measurements to determine the model parameters and the model's ability to account for shape differences of various roughness elements. It was found that the constant c, needed to determine the total stress τ and which was unspecified to date, can be assumed a value of about c =0.27. Values for the model parameter m, which accounts for the difference between the spatial surface average $${\tau _S^{\prime}}$$ and the peak $${\tau _S ^{\prime\prime}}$$ shear stress, are difficult to determine because m is a function of the roughness density, the wind velocity and the roughness element shape. A new definition for a parameter a is suggested as a substitute for m. This a parameter is found to be more closely universal and solely a function of the roughness element shape. It is able to predict the peak surface shear stress accurately. Finally, a method is presented to determine the new a parameter for different kinds of roughness element

Neurosensory and functional impairment in sagittal split osteotomies: a longitudinal and long-term follow-up study

The aim was to conduct a long-term follow-up study on the function and sensitivity of the mandible in advancement and setback patients after bilateral sagittal split osteotomy (BSSO) with rigid internal fixation. The advancement and setback groups consisted of 16 (12 females and 4 males, mean age: 21.4 and 21.3 years, respectively) and 17 (11 females and 6 males, mean age: 27.1 and 27.7 years, respectively). The final follow-up was a mean of 12.7 years (T4) post-operatively. The other follow-up examinations were before surgery (T1) and 7.3/6.6 (T2) and 13.9/14.4 (T3) months after surgery. To evaluate craniomandibular function, mouth-opening capacity, laterotrusion, protrusion, deviations during opening, pain and clicking of the temporomandibular joint (TMJ), muscular pain, and the retruded contact position-intercuspal position (RC-IP) distance were examined. A questionnaire was used to record subjective reports. The neurosensory status was determined with two-point discrimination (2-pd), the pointed, blunt, and light-touch tests. Statistical analysis included the following tests: Wilcoxon signed ranked matched pairs, Mann-Whitney U, paired t, and Fisher's exact test. Bonferroni's adjustments were made for evaluation of the questionnaire and Spearman's rank correlation coefficients to determine the interdependence of selected variables. Craniomandibular function showed restitution at T4 after 12.7 years. The 2-pd at the lip and chin had largely normalized in the two groups at T3. At T4, there was a significant increase of 2-pd at the lip and chin in both groups. The discrimination between sharp and blunt was limited in both groups in 25 per cent of patients at T4. Dysfunctions such as TMJ clicking, bruxism, and pain in the TMJ and muscles were neither increased nor decreased after BSSO. The initial post-surgical neurosensory impairment was barely detectable 1 year post-surgery. The new neurosensory impairment manifested at T4 was probably due to the normal human process of ageing. Neither age, gender, surgical advancement, nor setback showed any significant correlation

Sustainability assessment of land use systems

[no abstract

Biofumigation auch gegen pflanzenparasitische Nematoden?

Biofumigation refers to a biological method to reduce diseases, pests and weeds in the soil which is suitable for organic production systems. Cruciferous plants with a high level of Glucosinolates are grown for about two months in the field. To achieve the biofumigation effect, the intercrop is mulched during full bloom and rapidly incorporated into the soil. The Gluconisolates are converted during biological degradation into volatile substances toxic for certain diseases or pests. Nematodes are also sensitive to these substances and are reduced thereby. Besides using the incorporation of fresh plant material, pellets made of dried cruciferous plants and sold as fertilizer might be an alternative approach for nematode control. The pellets are incorporated into the soil before planting, avoiding the cultivation of plants for several months as in conventional biofumigation. First results from pot and greenhouse experiments show effects on plant growth, galling index and reproduction rate of root knot nematodes (Meloidogyne spp.). Further studies conducted at the Agroscope Changins-Wädenswil Research Station ACW are underway to evaluate the potential of this method for the control of different Meloidogyne-species and host plants

Stimulus Encoding and Feature Extraction by Multiple Sensory Neurons

Neighboring cells in topographical sensory maps may transmit similar information to the next higher level of processing. How information transmission by groups of nearby neurons compares with the performance of single cells is a very important question for understanding the functioning of the nervous system. To tackle this problem, we quantified stimulus-encoding and feature extraction performance by pairs of simultaneously recorded electrosensory pyramidal cells in the hindbrain of weakly electric fish. These cells constitute the output neurons of the first central nervous stage of electrosensory processing. Using random amplitude modulations (RAMs) of a mimic of the fish’s own electric field within behaviorally relevant frequency bands, we found that pyramidal cells with overlapping receptive fields exhibit strong stimulus-induced correlations. To quantify the encoding of the RAM time course, we estimated the stimuli from simultaneously recorded spike trains and found significant improvements over single spike trains. The quality of stimulus reconstruction, however, was still inferior to the one measured for single primary sensory afferents. In an analysis of feature extraction, we found that spikes of pyramidal cell pairs coinciding within a time window of a few milliseconds performed significantly better at detecting upstrokes and downstrokes of the stimulus compared with isolated spikes and even spike bursts of single cells. Coincident spikes can thus be considered “distributed bursts.” Our results suggest that stimulus encoding by primary sensory afferents is transformed into feature extraction at the next processing stage. There, stimulus-induced coincident activity can improve the extraction of behaviorally relevant features from the stimulus