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Theoretical study of electronic structure of silicon nanocrystals

We report on a theoretical study of the electronic structure of silicon nanocrystals with a shape of the regular rhombic dodecahedron, based on a tight-binding method. The energies of the lowest unoccupied state and the highest occupied state have been calculated. We have shown that the six-fold degenerate conduction band minima of the bulk silicon crystal are split into a non-degenerate A(1) stat

A phylogenetic study of the Lecanora rupicola group (Lecanoraceae, Ascomycota)

A molecular phylogeny of the Lecanora rupicola group is presented, based on ITS sequence analyses. The study includes saxicolous and corticolous members of the Lecanora rupicola group as well as other Lecanora species with pruinose apothecia. A phylogenetic hypothesis for species in Lecanora s. lat. and various other genera in Lecanoraceae, based on an alignment-free distance estimation technique,

Large eddy simulation and experimental studies of a confined turbulent swirling flow

Laser Doppler velocimetry (LDV) measurement and large eddy simulation (LES) were used to study confined isothermal turbulent swirling flows in a model dump combustor. The aim was to gain deeper understanding of the flow and turbulence structures in dump combustors and to examine the capability of LES for prediction of turbulent swirling flows. A refractive index matching technique is used in the L

Comparison of PMMA and SU-8 resist moulds for embossing of PZT to produce high-aspect-ratio microstructures using LIGA process

In this paper results are presented from a range of experiments to explore the feasibility of inserting a ceramic material PZT (lead zirconium titanate) into different kinds of high-aspect-ratio resist moulds. Polymethylmethacrylate (PMMA) and SU-8 on silicon substrates and free-standing SU-8 membranes with microcavities or through-holes (defined by X-ray lithography) have been used as moulding me

Compatibilizing effects of poly(styrene-graft-ethylene oxide) in blends of polystyrene and butyl acrylate polymers

The compatibilizing effect of poly(styrene-graft-ethylene oxide) in polystyrene (PS) blends with poly(n-butyl acrylate) (PBA) and poly(n-butyl acrylate-co-acrylic acid) (PBAAA) was investigated. No significant effects of the graft copolymer on the domain size were found in the PBA blends. By functionalizing PBA with acrylic acid, the average size of the polyacrylate domains was reduced considerabl

Endothelium-dependent relaxation in pulmonary arteries after lung preservation and transplantation

Pulmonary hypertension is frequently seen after lung transplantation. To study how the release of the endothelium-dependent relaxing factor is affected by lung preservation and transplantation, porcine pulmonary arteries were investigated in organ baths. The arteries (1 mm in diameter) were taken from fresh nonperfused lungs (group I), lungs immediately after flush-perfusion with a low-potassium-d

MHC class I variation associates with parasite resistance and longevity in tropical pythons

Using restriction fragment length polymorphism (RFLP) we identified 26 unique major histocompatibility complex (MHC) genotypes in 104 water pythons. We observed a significant independent association between reduced blood parasite load (Hepatozoon sp.) and python body length/age, presence of a specific RFLP fragment (C-fragment) and the overall number of fragments. The parasite has a negative impac

Fixation of microsporidian spores for electron microscopy

Fresh and frozen spores of the microsporidia Nosema apis and Nosema bombi were fixed using various fixatives at different times and temperatures. Paraformaldehyde and technical formaldehyde gave results comparable to or better than glutaraldehyde. Increased fixation temperature improved the fixation of spores from terrestrial hosts. Freezing did not destroy the cytology or the spore.

Discrepancy in mitochondrial and nuclear polymorphism in meadow vipers (Vipera ursinii) questions the unambiguous use of mtDNA in conservation studies

The sequence diversity of the entire mitochondrial control region (CR) of three meadow viper (Vipera ursinii) populations was analysed and compared to previously documented nuclear genetic variability at the major histocompatibility complex (MHC) Class I loci. One of the populations, a small and inbred Hungarian population, exhibited no MHC polymorphism, whereas the two other, sampled from large v

The effects of growth hormone (GH) deficiency and GH replacement on cognitive performance in adults: A meta-analysis of the current literature

Objective: There is growing evidence in the neuropsychological literature that growth hormone (GH) deficiency is associated with cognitive impairment. There is also evidence that this impairment may be ameliorated with GH replacement therapy. The current study assessed the nature and severity of cognitive impairment associated with growth hormone deficiency, as well as effect of GH replacement on

Variants in the SP110 gene are associated with genetic susceptibility to tuberculosis in West Africa

The sst1 locus has been identified in a mouse model to control resistance and susceptibility of Mycobacterium tuberculosis infection. Subsequent studies have now identified Ipr1 (intracellular pathogen resistance 1) to be the gene responsible. Ipr1 is encoded within the sst1 locus and is expressed in the tuberculosis lung lesions and macrophages of sst1-resistant, but not sst1-susceptible mice. We

Central venous oxygen saturation and thoracic admittance during dialysis: New approaches to hemodynamic monitoring

Intradialytic hypotension (IDH) is one of the most important short-term complications to hemodialysis (HD). Inadequate cardiac filling due to a reduction in the central blood volume is believed to be a major etiological factor. The aim of this study was to evaluate whether these pathophysiologic events are reflected in the central venous oxygen saturation (ScO2) and thoracic admittance (TA) during

Organizational Challenges to Sustainable Development

The concept of sustainable development at present permeates public discourse. An inter-organisational perspective can be used to analyse the processes through which this concept has found its way into policy and programme in four different settings: the United Nations, the European Communities, the government of Sweden and the city of Lund, Sweden. Although visible in treaties, laws and action pro

Encapsulation and selective recognition of molecularly imprinted theophylline and 17 ss-estradiol nanoparticles within electrospun polymer nanofibers

Molecularly imprinted nanoparticles are cross-linked polymer colloids containing tailor-made molecular recognition sites. In this study, molecularly imprinted nanoparticles were easily encapsulated within polymer nanofibers using an electrospinning technique to produce a new type of molecular recognition material. Poly(ethylene terephthalate) (PET) was used as the supporting nanofibers matrix to e

Taxonomic revision of the Pegomya meridiana species group (Diptera: Anthomyiidae) including natural enemies of invasive Hypericum spp. (Clusiaceae)

The Pegomya meridiana species group is established for three Palaearctic species that supposedly all as larvae attack seed-capsules of Hypericum spp. (Clusiaceae). Pegomya meridiana (Villeneuve) and P. provecta (Villeneuve) are widespread Eurasian species, while the third species, P. canariensis Michelsen, is endemic to the western Canary Islands. Synapomorphies for the Pegomya meridiana species g

Fluorescence studies on the interaction between pyrene-labelled poly(acrylic acid) and cyclodextrins

The interactions, in aqueous media, between a pyrene-labelled polyelectrolyte poly(acrylic acid) (PAAMePy) with two different degrees of labelling and beta- and gamma-cyclodextrins (beta- and gamma-CD) were studied using absorption and fluorescence (steady-state and time-resolved) techniques. In addition to qualitative and quantitative parameters obtained from absorption and steady-state fluoresce

Are incubation costs in female pied flycatchers expressed in humoral immune responsiveness or breeding success?

Although clutch size variation has been a key target for studies of avian life history theory, most empirical work has only focused on the ability of parents to raise their altricial young. In this study, we test the hypothesis that costs incurred during incubation may be an additional factor constraining clutch size in altricial birds. In the pied flycatcher (Ficedula hypoleuca), we manipulated t

Association between a variant in the 11 beta-hydroxysteroid dehydrogenase type 2 gene and primary hypertension

The enzyme 11 beta-hydroxysteroid dehydrogenase type 2 (11BHSD2) converts cortisol to cortisone in the kidney, thereby protecting the mineralocorticoid receptor from the mineralocorticoid actions of cortisol. The syndrome of Apparent Mineralocorticoid Excess (AME), a rare monogenic form of early onset hypertension with autosomal recessive inheritance, is caused by homozygous or compound heterozygo