A plane wave impinges on a perfectly conducting thick screen perforated with a periodic array of apertures with arbitrary cross-section. The transmission and reflection coefficients are determined by a mode matching technique, earlier used by other authors for the case where the apertures have the geometry of a classical waveguide. The fields outside the screen are expanded in Floquet modes, while

High-speed communication using the copper network, originally installed for telephony, is one of the dominant Internet access techniques. Several variants of a technology referred to as digital subscriber line (DSL) have been developed, standardized and installed during the last two decades. Essentially, DSL achieves high rates by exploiting wide bands of the copper cable channel. The shorter the

During glacial periods, dust deposition rates and inferred atmospheric concentrations were globally much higher than present. According to recent model results, the large enhancement of atmospheric dust content at the last glacial maximum (LGM) can be explained only if increases in the potential dust source areas are taken into account. Such increases are to be expected, due to effects of low prec

The PCR-mediated plasmid DNA deletion method is a simple approach to delete DNA sequences from plasmids using only one round of PCR, with two primers, and without ligation or purification prior to in vivo recombination. By using only PCR, the method is sequence independent and, as shown in this study, is applicable to various sizes of plasmids and deletions using minimal primer design.

The present study was designed to determine the interrelationships between sex, weaning age, and weaning weight on aspects of physiological and gastrointestinal development in pigs. Forty-eight Large White x Landrace pigs were used in a factorial arrangement with the respective factors being: age at weaning ( 14 or 28 days), weight at weaning ( heavy or light), sex ( boar or gilt), and time after

In this paper, a high-resolution finite volume method for calculating solutions to a hyperbolic conservation law is presented. The method works in two space dimensions on general domains and uses curvilinear meshes. A non-trivial estimation of gradients needed for the reconstructions is presented. The paper contains examples of numerical solutions of the Enter gas dynamics equations.

Aim. This paper reports a study investigating quality of life in relation to loneliness, caregiving, social network, gender, age and economic status among caregiving men and women in a population-based sample aged 75 years or older.Background. Because of demographic changes, in the future more care for older people will be given by informal caregivers who are themselves older. Being old and caring

To develop PDT beyond treatment of thin superficial tumours, to also be an efficient treatment alternative for deeply located and/or thick tumours, a system based on interstitial illumination using multiple fibres has been developed. Conditions that could benefit from such a treatment modality are for instance malignant brain tumours and tumours in the oral cavity. In interstitial PDT one needs to

Three intermediate to rhyolitic Icelandic Holocene tephra horizons (Hekla-3, Kebister, and Hekla-4) have been identified in annually laminated (varved) lake sediments in the Province of Varmland, west central Sweden. Calendar year ages were obtained from varve counts and are supported by additional C-14 dating based on terrestrial plant macrofossils. The varve ages of the three tephras are 3295 +/

InAs nanowire samples grown by metal-organic chemical vapor deposition present a significant amount of wurtzite structure, while the zincblende lattice is known to be the stable crystal structure for the bulk material. The question of the wurtzite distribution in the sample is addressed using phase-sensitive coherent X-ray diffraction with a micro-focused beam at a synchrotron source. The simultan

The island of Isla de los Estados is situated at 54.5 degrees S, 64 degrees W, east of Argentinian Tierra del Fuego, and is located in a sensitive geographic position in relation to the zonal circulation between Antarctica and South America. Its terrestrial records of the last deglaciation, recording atmospheric conditions but within an oceanic setting, can help to clarify changes of regional circ

In a distribution-wide phylogeographic survey of the field vole (Microtus agrestis), 75 specimens from 56 localities across Eurasia were examined for DNA sequence variation along the whole 1140 base pair (bp) mitochondrial (mt) cytochrome b gene. The species is subdivided into three main mtDNA phylogeographic groups - western, eastern and southern - with largely allopatric distributions. The weste

Swedish biomass production potential could be increased significantly if new production methods, such as optimised fertilisation, were to be used. Optimised fertilisation on 25% of Swedish forest land and the use of stem wood could almost double the biomass potential from forestry compared with no fertilisation, as both logging residues and large quantities of excess stem wood not needed for indus

This article links up with the debate in economic geography on "local buzz" and "global pipelines" as two distinct forms of interactive knowledge creation among firms and related actors and argues for a rethinking of the way social scientists should approach interactive knowledge creation. It highlights the importance of combining the insights from studies of clusters and innovation systems with a

The duration of breastfeeding has attracted much interest, as a prolonged period of breastfeeding has been shown to reduce the risk of developing obesity. The mechanism behind the reduced risk is, however, poorly understood. The novel hormone ghrelin augments appetite, promotes body. weight increase and increases adiposity. The majority of circulating ghrelin emanates from endocrine cells in the o

Mercury (Hg) is regarded as a major environmental concern in many regions, traditionally because of high concentrations in freshwater fish, and now also because of potential toxic effects on soil microflora. The predominant source of Hg in most watersheds is atmospheric deposition, which has increased 2- to >20-fold over the past centuries. A promising approach for supporting current European effo

The authors report the fabrication of gallium phosphide nanowire arrays that can be used for cellular force measurements. The nanowire positions are defined using electron beam lithography and the nanowires are grown using metal organic vapor phase epitaxy. By varying the nanowire diameter, length, and spacing from substrate to substrate, they can expect to probe cell forces over several orders of

The reversible effect of an induction dose of thiopental on the cerebral blood flow (CBF) was characterized by repeated 133Xe washout measurements during stable physiological conditions in anaesthetized pigs. A thiopental effect corresponding to induction of light and transient anaesthesia was confirmed by electroencephalography (EEG). The concentration (arterial plasma) -effect (-% CBF) relations