Where and how to manage: optimal selection of conservation actions for multiple species

Multiple alternative options are frequently available for the protection, maintenance or restoration of conservation areas. The choice of a particular management action can have large effects on the species occurring in the area, because different actions have different effects on different species. Together with the fact that conservation funds are limited and particular management actions are costly, it would be desirable to be able to identify where, and what kind of management should be applied to maximize conservation benefits. Currently available site-selection algorithms can identify the optimal set of sites for a reserve network. However, these algorithms have not been designed to answer what kind of action would be most beneficial at these sites when multiple alternative actions are available. We describe an algorithm capable of solving multi-species planning problems with multiple management options per site. The algorithm is based on benefit functions, which translate the effect of a management action on species representation levels into a value, in order to identify the most beneficial option. We test the performance of this algorithm with simulated data for different types of benefit functions and show that the algorithm¿s solutions are optimal, or very near globally optimal, partially depending on the type of benefit function used. The good performance of the proposed algorithm suggests that it could be profitably used for large multi-action multi-species conservation planning problems

Haptic feedback in a teleoperated box & blocks task

Haptic feedback is a desired feature in teleoperation as it can improve dexterous manipulation. Direct force feedback to the operator’s hand and fingers requires complex hardware and therefore substituting force by for instance vibration is a relevant topic. In this experiment, we tested performance on a Box &amp; Blocks task in a teleoperation set-up with no feedback, direct force feedback and substituted vibration feedback. Objective performance was the same in all conditions as was the learning effect over three sessions, but participants had a clear preference for haptic feedback over no haptic feedback. The preferred type of feedback (force or vibration or both) varied over participants. In general, this study showed that haptic feedback is preferred in teleoperation, the Box &amp; Blocks task seems not sensitive enough for our (and most) current teleoperation set-up(s), and vibration feedback as substitute for direct force feedback works well and can be used intuitively.</p

Optimization of sulfated cellulose membrane adsorbers for the purification of influenza virus

The impact of influenza virus worldwide drives significant efforts and resources into R&D of vaccine manufacturing processes. A major challenge is to improve the flexibility of these processes, without substantially compromising productivity. As in other biotechnological processes, implementation of a chromatographic capturing step is favored since it removes the majority of the impurities (host cell proteins and DNA) and concentrates the product before polishing. Over the last years, significant efforts towards the development of sulfated membrane adsorbers were made. An improved membrane structure and the direct sulfation of a cellulose matrix resulted in a membrane adsorber (SCMA) with pseudo-affinity characteristics which can be used in the main chromatographic separation step for influenza virus. Pore size and ligand density are structural characteristics critical for the performance of the SCMA. For the best combination tested, the dynamic binding capacity (DBC) of the SCMA was shown to be 5.6×106 HAU/mlmembrane, which corresponds to an approximately 5.5 times higher capacity than bead-based media. However, both SCMA and bead-based media show a similar performance in terms of product recovery (86%-96%) and contaminant removal. Experimental results revealed the importance of operational parameters like virus concentration, flow rate, conductivity and elution salt concentration. Therefore, a DoE was used to determine the optimal process conditions in terms of product losses in the flow through as well as overall product yield and purity for an optimized SCMA using an influenza H1N1 virus strain. Currently undergoing experiments aim the identification of the best operating conditions, reevaluation of the DBC and purification performance of the optimized SCMA for the same virus strain. The robustness of the process for other virus (e.g. influenza H3N2 and B) is also being considered. Combining the advantages of a membrane chromatographic support with a chemical modification that is shown to be specific for the purification of influenza virus is a significant technological advance. After optimization of the SCMA and the respective operating conditions significant improvements in the influenza vaccine production process are to be expected

The (cost) effectiveness of a very low-energy diet intervention with the use of eHealth in patients with type 2 diabetes and obesity:study protocol for a randomised controlled non-inferiority trial (E-diet trial)

BACKGROUND: Despite preventive measures, the number of people with type 2 diabetes and obesity is increasing. Obesity increases morbidity and mortality in people with type 2 diabetes, making weight loss a cornerstone of treatment. We previously developed a very low energy diet (VLED) intervention that effectively reduced weight in people with type 2 diabetes in the long term. However, this intervention requires considerable time and manpower, which reduces the number of people who can benefit from it. eHealth offers more efficient solutions but has proven to be less effective than face-to-face interventions. Therefore, we want to investigate whether a blended version of our VLED intervention (in which face-to-face contact is partly replaced by an eHealth (mobile) application (E-VLED)) would be more cost-effective than the current face-to-face intervention. METHODS: We will conduct a randomised, controlled trial with non-inferiority design in patients with type 2 diabetes and obesity (BMI &gt; 30 kg/m2), aged 18-75 years. The control group will receive the usual care VLED intervention, while the intervention group will receive the E-VLED intervention for 1 year, where face-to-face contact will be partly replaced by an eHealth (mobile) application. The main study endpoint is the difference in weight (% change) between the control and intervention group after 1 year, plus the difference between the total costs (euro) of the treatment in the control and intervention groups. The secondary aims are to investigate the effectiveness of the E-VLED diet intervention regarding cardiovascular risk factors, quality of life, patient satisfaction, compliance, and to study whether there is a difference in effectiveness in pre-specified subgroups. General linear models for repeated measurements will be applied for the statistical analysis of the data. DISCUSSION: We hypothesise that the E-VLED intervention will be equally effective compared to the usual care VLED but lower in costs due to less time invested by the dietician. This will enable to help more people with type 2 diabetes and obesity to effectively lose weight and improve their health-related quality of life. TRIAL REGISTRATION: Netherlands Trial Register, NL7832, registered on 26 June 2019.</p

Density functional theory of freezing for soft interactions in two dimensions

A density functional theory of two-dimensional freezing is presented for a soft interaction potential that scales as inverse cube of particle distance. This repulsive potential between parallel, induced dipoles is realized for paramagnetic colloids on an interface, which are additionally exposed to an external magnetic field. An extended modified weighted density approximation which includes correct triplet correlations in the liquid state is used. The theoretical prediction of the freezing transition is in good agreement with experimental and simulation data.Comment: 7 pages, 3 figures, submitted 200

Phase-field crystal modelling of crystal nucleation, heteroepitaxy and patterning

We apply a simple dynamical density functional theory, the phase-field-crystal (PFC) model, to describe homogeneous and heterogeneous crystal nucleation in 2d monodisperse colloidal systems and crystal nucleation in highly compressed Fe liquid. External periodic potentials are used to approximate inert crystalline substrates in addressing heterogeneous nucleation. In agreement with experiments in 2d colloids, the PFC model predicts that in 2d supersaturated liquids, crystalline freezing starts with homogeneous crystal nucleation without the occurrence of the hexatic phase. At extreme supersaturations crystal nucleation happens after the appearance of an amorphous precursor phase both in 2d and 3d. We demonstrate that contrary to expectations based on the classical nucleation theory, corners are not necessarily favourable places for crystal nucleation. Finally, we show that adding external potential terms to the free energy, the PFC theory can be used to model colloid patterning experiments.Comment: 21 pages, 16 figure

Influenza virus capture using membrane chromatography: Improving selectivity by matrix design and pseudo-affinity ligand interactions

Because next generation cell-based influenza vaccines have to be produced faster and in greater quantities than traditional vaccines, future purification processes will require more efficient unit operations for their isolation and purification. Membrane chromatography has already demonstrated a number of positive characteristics for the bind&elute purification of viral particles like e.g. adenoviruses or influenza viruses. The technology not only addresses the diffusion limitations of porous particle media but also offers dramatic advantages in binding capacity in a disposable format. Therefore, the last remaining challenge for the easy adoption of this technology in the vaccine industry represents selectivity and recovery. We present here a novel cellulose based stationary phase whose active specific surface area is designed for maximum virus accessibility. The resulting gain in selectivity and recovery but also in binding capacity is further maximized by using highly selective pseudo affinity ligands for influenza viruses

SPARC preserves endothelial glycocalyx integrity, and protects against adverse cardiac inflammation and injury during viral myocarditis

Myocardial damage as a consequence of cardiotropic viruses leads to a broad variety of clinical presentations and is still a complicated condition to diagnose and treat. Whereas the extracellular matrix protein Secreted Protein Acidic and Rich in Cysteine or SPARC has been implicated in hypertensive and ischemic heart disease by modulating collagen production and cross-linking, its role in cardiac inflammation and endothelial function is yet unknown. Absence of SPARC in mice resulted in increased cardiac inflammation and mortality, and reduced cardiac systolic function upon coxsackievirus-B3 induced myocarditis. Intra-vital microscopic imaging of the microvasculature of the cremaster muscle combined with electron microscopic imaging of the microvasculature of the cardiac muscle uncovered the significance of SPARC in maintaining endothelial glycocalyx integrity and subsequent barrier properties to stop inflammation. Moreover, systemic administration of recombinant SPARC restored the endothelial glycocalyx and consequently reversed the increase in inflammation and mortality observed in SPARC KO mice in response to viral exposure. Reducing the glycocalyx in vivo by systemic administration of hyaluronidase, an enzyme that degrades the endothelial glycocalyx, mimicked the barrier defects found in SPARC KO mice, which could be restored by subsequent administration of recombinant SPARC.In conclusion, the secreted glycoprotein SPARC protects against adverse cardiac inflammation and mortality by improving the glycocalyx function and resulting endothelial barrier function during viral myocarditis

Generation of defects and disorder from deeply quenching a liquid to form a solid

We show how deeply quenching a liquid to temperatures where it is linearly unstable and the crystal is the equilibrium phase often produces crystalline structures with defects and disorder. As the solid phase advances into the liquid phase, the modulations in the density distribution created behind the advancing solidification front do not necessarily have a wavelength that is the same as the equilibrium crystal lattice spacing. This is because in a deep enough quench the front propagation is governed by linear processes, but the crystal lattice spacing is determined by nonlinear terms. The wavelength mismatch can result in significant disorder behind the front that may or may not persist in the latter stage dynamics. We support these observations by presenting results from dynamical density functional theory calculations for simple one- and two-component two-dimensional systems of soft core particles.Comment: 25 pages, 11 figure