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The creation and manipulation of optical vortices, both in free space and in two-dimensional systems such as surface plasmon polaritons (SPPs), has attracted widespread attention in nano-optics due to their robust topological structure. Coupled with strong spatial confinement in the case of SPPs, these plasmonic vortices and their underlying orbital angular momentum (OAM) have promise in novel light-matter interactions on the nanoscale with applications ranging from on-chip particle manipulation to tailored control of plasmonic quasiparticles. Until now, predominantly integer OAM values have been investigated. Here, we measure and analyze the time evolution of fractional OAM SPPs using time-resolved two-photon photoemission electron microscopy and near-field optical microscopy. We experimentally show the field’s complex rotational dynamics and observe the beating of integer OAM eigenmodes at fractional OAM excitations. With our ability to access the ultrafast time dynamics of the electric field, we can follow the buildup of the plasmonic fractional OAM during the interference of the converging surface plasmons. By adiabatically increasing the phase discontinuity at the excitation boundary, we track the total OAM, leading to plateaus around integer OAM values that arise from the interplay between intrinsic and extrinsic OAM., QN/Kuipers Lab, QN/Quantum Nanoscience

Background: The foot progression angle is an important measure used to help patients reduce their knee adduction moment. Current measurement systems are either lab-bounded or do not function in all environments (e.g., magnetically distorted). This work proposes a novel approach to estimate foot progression angle using a single foot-worn inertial sensor (accelerometer and gyroscope). Methods: The approach uses a dynamic step frame that is recalculated for the stance phase of each step to calculate the foot trajectory relative to that frame, to minimize effects of drift and to eliminate the need for a magnetometer. The foot progression angle (FPA) is then calculated as the angle between walking direction and the dynamic step frame. This approach was validated by gait measurements with five subjects walking with three gait types (normal, toe-in and toe-out). Results: The FPA was estimated with a maximum mean error of ~ 2.6° over all gait conditions. Additionally, the proposed inertial approach can significantly differentiate between the three different gait types. Conclusion: The proposed approach can effectively estimate differences in FPA without requiring a heading reference (magnetometer). This work enables feedback applications on FPA for patients with gait disorders that function in any environment, i.e. outside of a gait lab or in magnetically distorted environments., Biomechatronics & Human-Machine Control

Despite aerobic granular sludge wastewater treatment plants operating around the world, our understanding of internal granule structure and its relation to treatment efficiency remains limited. This can be attributed in part to the drawbacks of time-consuming, labor-intensive, and invasive microscopy protocols which effectively restrict samples sizes and may introduce artefacts. Time-domain nuclear magnetic resonance (NMR) allows non-invasive measurements which describe internal structural features of opaque, complex materials like biofilms. NMR was used to image aerobic granules collected from five full-scale wastewater treatment plants in the Netherlands and United States, as well as laboratory granules and control beads. T1 and T2 relaxation-weighted images reveal heterogeneous structures that include high- and low-density biofilm regions, water-like voids, and solid-like inclusions. Channels larger than approximately 50 μm and connected to the bulk fluid were not visible. Both cluster and ring-like structures were observed with each granule source having a characteristic structural type. These structures, and their NMR relaxation behavior, were stable over several months of storage. These observations reveal the complex structures within aerobic granules from a range of sources and highlight the need for non-invasive characterization methods like NMR to be applied in the ongoing effort to correlate structure and function., Sanitary Engineering

Hippocampal volume and shape are known magnetic resonance imaging biomarkers of neurodegeneration. Recently, hippocampal texture has been shown to improve prediction of dementia in patients with mild cognitive impairment, but it is unknown whether texture adds prognostic information beyond volume and shape and whether the predictive value extends to cognitively healthy individuals. Using 510 subjects from the Rotterdam Study, a prospective, population-based cohort study, we investigated if hippocampal volume, shape, texture, and their combination were predictive of dementia and determined how predictive performance varied with time to diagnosis and presence of early clinical symptoms of dementia. All features showed significant predictive performance with the area under the receiver operating characteristic curve ranging from 0.700 for texture alone to 0.788 for the combination of volume and texture. Although predictive performance extended to those without objective cognitive complaints or mild cognitive impairment, performance decreased with increasing follow-up time. We conclude that a combination of multiple hippocampal features on magnetic resonance imaging performs better in predicting dementia in the general population than any feature by itself., ImPhys/Quantitative Imaging

Methane is a potent greenhouse gas, which can be converted by microorganism at the expense of oxygen, nitrate, nitrite, metal-oxides or sulfate. The bacterium 'Candidatus Methylomirabilis oxyfera,' a member of the NC10 phylum, is capable of nitrite-dependent anaerobic methane oxidation. Prolonged enrichment of 'Ca. M. oxyfera' with cerium added as trace element and without nitrate resulted in the shift of the dominant species. Here, we present a high quality draft genome of the new species 'Candidatus Methylomirabilis lanthanidiphila' and use comparative genomics to analyze its metabolic potential in both nitrogen and carbon cycling. To distinguish between gene content specific for the 'Ca. Methylomirabilis' genus and the NC10 phylum, the genome of a distantly related NC10 phylum member, CSP1-5, an aerobic methylotroph, is included in the analysis. All genes for the conversion of nitrite to N2 identified in 'Ca. M. oxyfera' are conserved in 'Ca. M. lanthanidiphila,' including the two putative genes for NO dismutase. In addition both species have several heme-copper oxidases potentially involved in NO and O2 respiration. For the oxidation of methane 'Ca. Methylomirabilis' species encode a membrane bound methane monooxygenase. CSP1-5 can act as a methylotroph, but lacks the ability to activate methane. In contrast to 'Ca. M. oxyfera,' which harbors three methanol dehydrogenases (MDH), both CSP1-5 and 'Ca. M. lanthanidiphila' only encode a lanthanide-dependent XoxF-type MDH, once more underlining the importance of rare earth elements for methylotrophic bacteria. The pathways for the subsequent oxidation of formaldehyde to carbon dioxide and for the Calvin-Benson-Bassham cycle are conserved in all species. Furthermore, CSP1-5 can only interconvert nitrate and nitrite, but lacks subsequent nitrite or NO reductases. Thus, it appears that although the conversion of methanol to carbon dioxide is present in several NC10 phylum bacteria, the coupling of nitrite, BT/Management Office, BT/Environmental Biotechnology

Accumulating evidence suggests that genetic variants in the SORL1 gene are associated with Alzheimer disease (AD), but a strategy to identify which variants are pathogenic is lacking. In a discovery sample of 115 SORL1 variants detected in 1908 Dutch AD cases and controls, we identified the variant characteristics associated with SORL1 variant pathogenicity. Findings were replicated in an independent sample of 103 SORL1 variants detected in 3193 AD cases and controls. In a combined sample of the discovery and replication samples, comprising 181 unique SORL1 variants, we developed a strategy to classify SORL1 variants into five subtypes ranging from pathogenic to benign. We tested this pathogenicity screen in SORL1 variants reported in two independent published studies. SORL1 variant pathogenicity is defined by the Combined Annotation Dependent Depletion (CADD) score and the minor allele frequency (MAF) reported by the Exome Aggregation Consortium (ExAC) database. Variants predicted strongly damaging (CADD score >30), which are extremely rare (ExAC-MAF <1 × 10 '5) increased AD risk by 12-fold (95% CI 4.2-34.3; P=5 × 10 '9). Protein-truncating SORL1 mutations were all unknown to ExAC and occurred exclusively in AD cases. More common SORL1 variants (ExAC-MAF≥1 × 10 '5) were not associated with increased AD risk, even when predicted strongly damaging. Findings were independent of gender and the APOE-I 4 allele. High-risk SORL1 variants were observed in a substantial proportion of the AD cases analyzed (2%). Based on their effect size, we propose to consider high-risk SORL1 variants next to variants in APOE, PSEN1, PSEN2 and APP for personalized risk assessments in clinical practice., Pattern Recognition and Bioinformatics

The inherent stochasticity of molecular reactions prevents us from predicting the exact state of single-cells in a population. However, when a population grows at steady-state, the probability to observe a cell with particular combinations of properties is fixed. Here we validate and exploit existing theory on the statistics of single-cell growth in order to predict the probability of phenotypic characteristics such as cell-cycle times, volumes, accuracy of division and cell-age distributions, using real-time imaging data for Bacillus subtilis and Escherichia coli. Our results show that single-cell growth-statistics can accurately be predicted from a few basic measurements. These equations relate different phenotypic characteristics, and can therefore be used in consistency tests of experimental single-cell growth data and prediction of single-cell statistics. We also exploit these statistical relations in the development of a fast stochastic-simulation algorithm of single-cell growth and protein expression. This algorithm greatly reduces computational burden, by recovering the statistics of growing cell-populations from the simulation of only one of its lineages. Our approach is validated by comparison of simulations and experimental data. This work illustrates a methodology for the prediction, analysis and tests of consistency of single-cell growth and protein expression data from a few basic statistical principles., BN/Marileen Dogterom Lab

Climate change is expected to cause higher discharge levels in the river Rhine at the Dutch-German border. In this study group project that was commissioned by Rijkswaterstaat , we investigate the possibility of flooding the Rijnstrangen area as a protective measure. We identify three subproblems. We first analyze the data recorded by Rijkswaterstaat and estimate the likelihood and the duration of extremely large discharges at the German border into the river. Next, we investigate how a change in discharge levels affects the water height in the first 35 kilometer section in the Netherlands. Finally we study the design of weirs and floodgates to allow diverting a sufficiently large amount of water flow from the river into the retention area. Our statistical analysis shows that an extreme discharge level is expected to occur once every 1250 years and to last for about three and a half days. Our numerical flow model shows the water height reaches equilibrium on a time scale that is much smaller than the one on which flooding occurs. The flow can thus be considered quasi-stationary. Passive weirs finally are shown to be too long to be feasible. Actively controlled floodgates are therefore recommended., Delft Institute of Applied Mathematics, Electrical Engineering, Mathematics and Computer Science

Applied Sciences

The invention relates to a method of the dosed application of a liquid onto to selected portion of the surface of a substrate (A) by means of spraying under the influence of an electric current. According to the invention the liquid is fed at a flow rate between 0.01 pl/s and 1 ml/s to a distal tip ( 3 ) of a capillary ( 1 ) having an inside diameter of less than 150 mum, wherein the distance between the distal tip and the surface (A) is less than 2 mm. Surprisingly it has been shown that it is possible in this manner to apply liquid to a restricted surface of a defined size., Applied Sciences

Electrical Engineering, Mathematics and Computer Science

Applied Sciences

This project dissertation entitled 'Death and Grief: A Proposed 'Cycle of Compassion'' hinged on two hypotheses which received a favorable hearing at the Lakeside United Methodist Church in Huntsville, Alabama January 1990. The first hypothesis stated that the church is the important place for teaching grief awareness and resolution. Hypothesis Two asserted that a cycle of compassion is a process that the minister can develop with the congregation to overcome death and grief. There were several reasons why these hypotheses were operant in this project dissertation. Hypothesis One was validated because people do gather at church and problems with grief will always be a part of the human predicament. Moreover, this hypothesis espoused the belief that grief has to become a conscious reality before it can be resolved. Hypothesis Two rightly assumed that the minister and congregation are human agents of divine comparison to the bereaved. The significance of this study for other congregations lay in the fact that it brought together a coalition of several ministry emphases---evangelism, missions, worship and Christian education---through which the cycle of compassion may find development and fruition. The cycle of compassion fills the void after the crowd thins out and the banquet is over. It also moves immediately to settle down with the griever in an extended period of grief sharing and healing. Through it all, God takes the initiative in putting our shattered lives back together again.