Density-dependent prophylaxis and condition-dependent immune function in Lepidopteran larvae: a multivariate approach

1. The risk of parasitism and infectious disease is expected to increase with population density as a consequence of positive density-dependent transmission rates. Therefore, species that encounter large fluctuations in population density are predicted to exhibit plasticity in their immune system, such that investment in costly immune defences is adjusted to match the probability of exposure to parasites and pathogens (i.e. density-dependent prophylaxis).

Distribution of the Demmel Condition Number of Wishart Matrices

This paper studies the Demmel condition number of Wishart matrices, a quantity which has numerous applications to wireless communications, such as adaptive switching between beamforming and diversity coding, link adaptation, and spectrum sensing. For complex Wishart matrices, we give an exact analytical expression for the probability density function (p.d.f.) of the Demmel condition number, and also derive simplified expressions for the high tail regime. These results indicate that the condition of complex Wishart matrices is dominantly decided by the difference between the matrix dimension and degree of freedom (DoF), i.e., the probability of drawing a highly ill conditioned matrix decreases considerably when the difference between the matrix dimension and DoF increases. We further investigate real Wishart matrices, and derive new expressions for the p.d.f. of the smallest eigenvalue, when the difference between the matrix dimension and DoF is odd. Based on these results, we succeed to obtain an exact p.d.f. expression for the Demmel condition number, and simplified expressions for the high tail regime.

The assimilation and chronic effects of sub-lethal concentrations of Endosulfan on condition and spawning in the common mussel Mytilus edulis

The rate of uptake of Endosulfan by Mytilus edulis L. exposed to pesticide concentrations of 0.1, 0.5, and 1.0 mg/l, and its subsequent elution on removal to clean sea water, was investigated. Higher residue levels were recorded for mussels exposed to higher concentrations of the pesticide, but concentration factors were reduced. There was a rapid initial fall in tissue residue levels on transfer to clean sea water due, it is suggested, to elution of Endosulfan adsorbed on particulate matter assimilated in the gut. The spawning period was prolonged at higher concentrations and, at 1.0 mg/l, the onset of spawning was delayed, possibly due to interference with gamonic action. At 0.1 mg/l, the minor protraction of the spawning period may reflect the effect of experimental tank conditions. No seasonal trend was obvious, and there was an exaggeration of the expected fall in condition in mussels exposed to higher concentrations of Endosulfan. In controls, the expected seasonal trend was reduced.

The Contemporary Urban Condition: Understanding the Globalizing City as Informal, Contested, and Anchored.

In attempting to expand the vocabulary of urban description and understanding, and to offer a new composite conceptual framework for a more integrated urban planning and policy, this essay addresses the informal, contested, and anchored dimensions of the urban in turn; second, it seeks to increasingly link the three within the new global context; and finally, it attempts to draw these strands together in a proposed reconceptualization of the contemporary city within a world where the global is urbanizing and the urban is globalizing.

Building Stone Condition Monitoring Using Specially Designed Compensated Optical Fiber Humidity Sensors

This paper presents the design and implementation of a novel optical fiber temperature compensated relative humidity (RH) sensor device, based on fiber Bragg gratings (FBGs) and developed specifically for monitoring water ingress leading to the deterioration of building stone. The performance of the sensor thus created, together with that of conventional sensors, was first assessed in the laboratory where they were characterized under experimental conditions of controlled wetting and drying cycles of limestone blocks, before being employed “in-the-field” to monitor actual building stone in a specially built wall. Although a new construction, this was built specifically using conservation methods similar to those employed in past centuries, to allow an accurate simulation of processes occurring with wetting and drying in the historic walls in the University of Oxford.

Fibre-optic strain sensor system with temperature compensation for arch bridge condition monitoring

This paper presents an innovative sensor system, created specifically for new civil engineering structural monitoring applications, allowing specially packaged fiber grating-based sensors to be used in harsh, in-the-field measurement conditions for accurate strain measurement with full temperature compensation. The sensor consists of two fiber Bragg gratings that are protected within a polypropylene package, with one of the fiber gratings isolated from the influence of strain and thus responding only to temperature variations, while the other is sensitive to both strain and temperature. To achieve this, the temperature-monitoring fiber grating is slightly bent and enclosed in a metal envelope to isolate it effectively from the strain. Through an appropriate calibration process, both the strain and temperature coefficients of each individual grating component when incorporated in the sensor system can be thus obtained. By using these calibrated coefficients in the operation of the sensor, both strain and temperature can be accurately determined. The specific application for which these sensors have been designed is seen when installed on an innovative small-scale flexi-arch bridge where they are used for real-time strain measurements during the critical installation stage (lifting) and loading. These sensors have demonstrated enhanced resilience when embedded in or surface-mounted on such concrete structures, providing accurate and consistent strain measurements not only during installation but subsequently during use. This offers an inexpensive and highly effective monitoring system tailored for the new, rapid method of the installation of small-scale bridges for a variety of civil engineering applications.

Epitaxial strain and electric boundary condition effects on the structural and ferroelectric properties of BiFeO3 films

The influence of both compressive and tensile epitaxial strain along with the electrical boundary conditions on the ferroelastic and ferroelectric domain patterns of bismuth ferrite films was studied. BiFeO3 films were grown on SrTiO3(001), DyScO3(110), GdScO3(110), and SmScO3(110) substrates to investigate the effect of room temperature in-plane strain ranging from -1.4% to +0.75%. Piezoresponse force microscopy, transmission electron microscopy, x-ray diffraction measurements, and ferroelectric polarization measurements were performed to study the properties of the films. We show that BiFeO3 films with and without SrRuO3 bottom electrode have different growth mechanisms and that in both cases reduction of the domain variants is possible. Without SrRuO3, stripe domains with reduced variants are formed on all rare earth scandate substrates because of their monoclinic symmetry. In addition, tensile strained films exhibit a rotation of the unit cell with increasing film thickness. On the other side, the presence of SrRuO3 promotes step flow growth of BiFeO3. In case of vicinal SrTiO3 and DyScO3 substrates with high quality SrRuO3 bottom electrode and a low miscut angle of approximate to 0.15 degrees we observed suppression of the formation of certain domain variants. The quite large in-plane misfit of SrRuO3 with GdScO3 and SmScO3 prevents the growth of high quality SrRuO3 films and subsequent domain variants reduction in BiFeO3 on these substrates, when SrRuO3 is used as a bottom electrode.