Some aspects of the biology of Dermestes maculatus Degeer (Coleoptera,Dermestidae) in dried fish

The development of Dermestes maculatus Deg. in dried fish has been studied under uncontrolled laboratory conditions. Females laid eggs within 12 hr of copulation, and oviposition was improved by the presence of free water. Hatching occurred about 48 hr after oviposition. The characteristic appearance of the egg and the changes that occurred during incubation and hatching are described. Larval development was completed in 33·5 days during which seven moults occurred and a body length of 14 mm was attained. Larval life was prolonged by crowding. When intact pieces of fish were available, the last instar larva bored into one of them and pupated within the hardened larval skin, but when ground fish was provided, a quiescent prepupal stage was observed. The adult emerged about 11 days after the last instar larval stage, irrespective of the mode of pupation.     

Small and large polarons in nickelates, manganites, and cuprates

By comparing the optical conductivities of La_1.67Sr_0.33NiO₄ (LSNO), Sr_1.5La_0.5MnO₄ (SLMO), Nd₂CuO_4-y (NCO), and Nd_1.96Ce_0.04CuO₄ (NCCO), we have identified a peculiar behavior of polarons in this cuprate family. Whereas in LSNO and SLMO small polarons localize into ordered structures below a transition temperature, in these cuprates the polarons appear to be large, and at lowT their binding energy decreases. This reflects an increase of the polaron radius, which may trigger coherent transport.     

Short-Period GaMnAs/GaAs Superlattices: Optical and Magnetic Characterization

Superlattices with magnetic layers containing from 8 to 16 GaMnAs monolayers corresponding to the mixed crystal composition between 5 and 6% of Mn and from 4 to 10 GaAs monolayers were grown by the low temperature MBE technique and characterized by Raman scattering. Folded acoustic phonons were observed for all superlattices in the Raman scattering spectra. The interlayer exchange coupling, found previously by the wide-angle neutron diffraction in selected superlattices was investigated by the spin-polarized neutron reflectometry. It was always of ferromagnetic type, no trace of antiferromagnetic coupling was found.     

3D-Druck für Hochvakuumanwendungen

To mark our anniversary, we are presenting articles that have been particularly appreciated by readers of our online edition once again in print. Here: 3D-Printing for High Vacuum Applications 3D printing technology has made the leap from a home-based private practice to industrial manufacturing. Due to the increasing reliability of printers and increasing material diversity, especially in the metal sector, double-digit percentage growth rates are possible in the coming years. This thesis deals with the manufacture of parts made by 3D printing for high vacuum application. Different components are printed and examined for their vacuum compatibility. As shown furthermore, conventionally made standard components can be vacuum sealed to printed parts, which enables cost-effective production of more complex components, such as e.g. a vacuum chamber allows. In addition, functional components can already be realized in the manufacturing process. The integration of a system of flow channels directly into the wall of a chamber is just one example. Thus, such a chamber can be heated during evacuation and effectively cool in later operation.     

Relaxing high-dimensional constraints in the direct solution space method for early phase development

Early phase distributed system design can be accomplished using solution spaces that provide an interval of permissible values for each functional parameter. The feasibility property guarantees fulfillment of all design requirements for all possible realizations. Flexibility denotes the size measure of the intervals, with higher flexibility benefiting the design process. Two methods are available for solution space identification. The direct method solves a computationally cheap optimization problem. The indirect method employs a sampling approach that requires a relaxation of the feasibility property through re-formulation as a chance constraint. Even for high probabilities of fulfillment, \(P>0.99\), this results in substantial increases in flexibility, which offsets the risk of infeasibility. This work implements the chance constraint formulation into the direct method for linear constraints by showing that its problem statement can be understood as a linear robust optimization problem. Approximations of chance constraints from the literature are transferred into the context of solution spaces. From this, we derive a theoretical value for the safety parameter \(\varOmega\). A further modification is presented for use cases, where some intervals are already predetermined. A problem from vehicle safety is used to compare the modified direct and indirect methods and discuss suitable choices of \(\varOmega\). We find that the modified direct method is able to identify solution spaces with similar flexibility, while maintaining its cost advantage.     

Conduction in thin polymer films

Thin polymer films have been made from a variety of starting monomers and their electrical conduction has been studied.The films are produced both by ultraviolet surface photolysis and by a cold-cathode glow-discharge technique. The samples are made in the form of a capacitor sandwich on a glass substrate with aluminium electrodes. The whole sample is made in a high-vacuum system, without breaking vacuum, using out-of-contact masking techniques.Generally, depending on the starting monomer, the polymer films are short-free down to a thickness of about 100 Å, and electric fields up to 10⁷ V/cm may be sustained.The current/voltage characteristics of the films have been investigated as a function of temperature and thickness. One theory to account for the conduction in these materials is presented and compared with other approaches to the problem.     

Ultrasound‒Mediated Synthesis of High‒Molecular Weight Polystyrene‒Grafted Silver Nanoparticles by Facile Ligand Exchange Reactions in Suspension

Ultrasound mediated facile ligand exchange method in suspension for the formation of polystyrene?grafted silver nanoparticles is reported. Amazingly, this method allows even grafting of very high molecular weight polystyrenes (up to 217 200 g mol^?1) having a single terminal thiol group at the chain end. Detailed studies are carried out to gain insights in the role of molecular weight of the ligands and the mechanism of the ligand exchange reactions. Key factors are determined to be the droplet formation by ultrasonification and low silver content, which enhances the availability of the terminal thiol end group significantly. The extraordinary compatibility of the ligand exchange method in particular regarding high molecular weights is attributed to hydrophilic orientation of the terminal thiol groups at the liquid?liquid interphase. This is proved conclusively by using an in situ method as a reference approach in which agglomeration occurs at considerably lower molecular weights due to the absence of preferred end group orientation within the polymer coil. In homogeneous phase only the chain length is found to be the crucial factor in stabilization of silver nanoparticles.     

Modelling HIV-1 2-LTR dynamics following raltegravir intensification

A model of reservoir activation and viral replication is introduced accounting for the production of 2-LTR HIV-1 DNA circles following antiviral intensification with the HIV integrase inhibitor raltegravir, considering contributions of de novo infection events and exogenous sources of infected cells, including quiescent infected cell activation. The model shows that a monotonic increase in measured 2-LTR concentration post intensification is consistent with limited de novo infection primarily maintained by sources of infected cells unaffected by raltegravir, such as quiescent cell activation, while a transient increase in measured 2-LTR concentration is consistent with significant levels of efficient (R₀ > 1) de novo infection. The model is validated against patient data from the INTEGRAL study and is shown to have a statistically significant fit relative to the null hypothesis of random measurement variation about a mean. We obtain estimates and confidence intervals for the model parameters, including 2-LTR half-life. Seven of the 13 patients with detectable 2-LTR concentrations from the INTEGRAL study have measured 2-LTR dynamics consistent with significant levels of efficient replication of the virus prior to treatment intensification.