Pioniersgeest blijft: op het bedrijf van de Jonkmannen zorgen pompoenen voor continuïteit

Fokke Jonkman is opgegroeid in de (biologische) landbouw, hij maakte eerst de omschakeling naar biologisch-dynamisch mee en daarna de verhuizing vanuit Andijk naar de Bronsweg in Lelystad. Dat betekende veel improviseren en uitproberen. Het pionieren zit nog steeds in zijn bloed, al doet Fokke het intussen wat rustiger aan. De percelen en de schuur zien er overzichtelijk en strak uit. In de tuin rondom het woonhuis overheersen ronde vormen, vele soorten fruitbomen en inheemse plantensoorten groeien hier weelderig door elkaar

Surface-wave-enabled darkfield aperture for background suppression during weak signal detection

Sensitive optical signal detection can often be confounded by the presence of a significant background, and, as such, predetection background suppression is substantively important for weak signal detection. In this paper, we present a novel optical structure design, termed surface-wave-enabled darkfield aperture (SWEDA), which can be directly incorporated onto optical sensors to accomplish predetection background suppression. This SWEDA structure consists of a central hole and a set of groove pattern that channels incident light to the central hole via surface plasmon wave and surface-scattered wave coupling. We show that the surface wave component can mutually cancel the direct transmission component, resulting in near-zero net transmission under uniform normal incidence illumination. Here, we report the implementation of two SWEDA structures. The first structure, circular-groove-based SWEDA, is able to provide polarization-independent suppression of uniform illumination with a suppression factor of 1230. The second structure, linear-groove-based SWEDA, is able to provide a suppression factor of 5080 for transverse-magnetic wave and can serve as a highly compact (5.5 micrometer length) polarization sensor (the measured transmission ratio of two orthogonal polarizations is 6100). Because the exact destructive interference balance is highly delicate and can be easily disrupted by the nonuniformity of the localized light field or light field deviation from normal incidence, the SWEDA can therefore be used to suppress a bright background and allow for sensitive darkfield sensing and imaging (observed image contrast enhancement of 27 dB for the first SWEDA)

Oscillations of a gas pocket on a liquid-covered solid surface

The dynamic response of a gas bubble entrapped in a cavity on the surface of a submerged solid subject to an acoustic field is investigated in the linear approximation. We derive semi-analytical expressions for the resonance frequency, damping and interface shape of the bubble. For the liquid phase, we consider two limit cases: potential flow and unsteady Stokes flow. The oscillation frequency and interface shape are found to depend on two dimensionless parameters: the ratio of the gas stiffness to the surface tension stiffness, and the Ohnesorge number, representing the relative importance of viscous forces. We perform a parametric study and show, among others, that an increase in the gas pressure or a decrease in the surface tension leads to an increase in the resonance frequency until an asymptotic value is reached

Towards a Framework for Alignment Between Automotive Safety and Security Standards

Modern automotive systems increasingly rely on software and network connectivity for new functions and features. Security of the software and communications of the on-board system of systems becomes a critical concern for the safety of new generation vehicles. Besides methods and tools, safety and security of automotive systems requires frameworks of standards for holistic process and assurance. As a part of our ongoing work, this paper investigates the possibility of a combined safety and security approach to standards in the automotive domain. We examine existing approaches in the railway and avionics domain with similar challenges and identify speci c requirements for the automotive domain. We evaluate ISO 15408 as a potential candidate for a combined safety and security approach for complementing automotive safety standard ISO 26262, and discuss their points of alignment

The HLA diversity of the Anthony Nolan register

While the success of allogeneic stem cell transplantation depends on a high degree of HLA compatibility between donor and patient, finding a suitable donor remains challenging due to the hyperpolymorphic nature of HLA genes. We calculated high‐resolution allele, haplotype and phenotype frequencies for HLA‐A, ‐C, ‐B, ‐DRB1 and ‐DQB1 for 10 subpopulations of the Anthony Nolan (AN) register using an in‐house expectation‐maximisation (EM) algorithm run on mixed resolution HLA data, covering 676 155 individuals. Sample sizes range from 599 410 for British/Irish North West European (BINWE) individuals, the largest subpopulation in the United Kingdom to 1105 for the British Bangladeshi population. Calculation of genetic distance between the subpopulations based on haplotype frequencies shows three broad clusters, each following a major continental group: European, African and Asian. We further analysed the HLA haplotype and phenotype diversity of each subpopulation, and found that 35.52% of BINWE individuals ranging to 98.34% of Middle Eastern individuals on the register had a unique phenotype within their subpopulation. These analyses and the allele, haplotype and phenotype frequency data of the subpopulation on the AN register are a valuable resource in understanding the HLA diversity in the United Kingdom and can be used to improve the accuracy of match likelihoods and to inform future donor recruitment strategies

Most significant changes experienced by farmers from adopting rainforestation farming

The Visayas State University (VSU) developed the rainforestation farming (RF) system to replace the more destructive forms of kaingin or slash-and-burn practices commonly practiced by farmers and provide them with a stable and higher income. VSU disseminated the technology through training and establishment of demonstration farms coupled with various extension materials. The most important changes experienced by farmers from adopting RF were increase in income, greater social skills, improvement of their water and air conditions, and enhancement of biodiversity in their rainforestation farms

CD4+ T-cell responses to Epstein-Barr virus (EBV) latent-cycle antigens and the recognition of EBV-transformed lymphoblastoid cell lines

There is considerable interest in the potential of Epstein-Barr virus (EBV) latent antigen-specific CD4$^+$ T cells to act as direct effectors controlling EBV-induced B lymphoproliferations. Such activity would require direct CD4$^+$ T-cell recognition of latently infected cells through epitopes derived from endogenously expressed viral proteins and presented on the target cell surface in association with HLA class II molecules. It is therefore important to know how often these conditions are met. Here we provide CD4$^+$ epitope maps for four EBV nuclear antigens, EBNA1, -2, -3A, and -3C, and establish CD4$^+$ T-cell clones against 12 representative epitopes. For each epitope we identify the relevant HLA class II restricting allele and determine the efficiency with which epitope-specific effectors recognize the autologous EBV-transformed B-lymphoblastoid cell line (LCL). The level of recognition measured by gamma interferon release was consistent among clones to the same epitope but varied between epitopes, with values ranging from 0 to 35% of the maximum seen against the epitope peptide-loaded LCL. These epitope-specific differences, also apparent in short-term cytotoxicity and longer-term outgrowth assays on LCL targets, did not relate to the identity of the source antigen and could not be explained by the different functional avidities of the CD4$^+$ clones; rather, they appeared to reflect different levels of epitope display at the LCL surface. Thus, while CD4$^+$ T-cell responses are detectable against many epitopes in EBV latent proteins, only a minority of these responses are likely to have therapeutic potential as effectors directly recognizing latently infected target cells

Melting of olive oil in immiscible surroundings: experiments and theory

We report on the melting dynamics of frozen olive oil in quiescent water for Rayleigh numbers up to $10^9$. The density difference results in an upward buoyancy-driven flow of liquid oil forming a thin film around the frozen oil. We experimentally investigate flat, cylindrical, and spherical shapes and we derive theoretical expressions for the local film thickness, velocity, and the local melt rate for these three canonical geometries. Our theoretical models compare favourably with our experimental findings.Comment: 18 pages, 9 figures, to be submitte