The influence of ion implantation by phosphorous on structural changes in porous silicon

Structural changes in the surface layer of technologically treated silicon by ion implantation, chemical etching, and their combined action have been investigated by the X-ray diffractometry methods. The functional and quantitative differences in the thickness dependences of strains, values of maximum strain, level of lattice disturbance and extension of elastic strains nave been revealed after different steps of treatment. The essential modification of photoluminescence spectra was observed in the porous layer after implantation by phosphorus ions in the process of natural aging

Structural and magnetic properties of GaMnAs layers with high Mn content grown by Migration Enhanced Epitaxy on GaAs(100) substrates

We have grown the ferromagnetic semiconductor GaMnAs containing up to 10% Mn by migration enhanced epitaxy at a substrate temperature of 150^oC. The alternate supply of As2 molecules and Ga and Mn atoms made it possible to grow single crystalline GaMnAs layers at very low substrate temperature, at which conventional molecular beam epitaxial growth under excess As supply is not possible due to As condensation. Secondary ion mass spectroscopy and X-ray diffraction measurements confirmed a higher Mn content in the films grown by this method in comparison to the GaMnAs layers grown by low temperature molecular beam epitaxy. The lattice constant of hypothetical zinc-blende structure MnAs is determined to be 5.9 \AA, which deviates somewhat from previously reported values. This deviation is ascribed to growth-condition dependent density of point defects. It is stressed that this effect must be taken into account for any assessment of Mn content from X-ray diffraction data. Magnetization measurements showed an onset of ferromagnetic ordering around 75 K for the GaMnAs layer with 10% Mn. This means that the trend of falling Curie temperatures with increasing Mn concentrations above 5.5% is broken. We tentatively assign this to the variation of the carrier concentration, including contributions from donor and acceptor centers formed by antisite defects and Mn doping, and increased density of magnetically active Mn ions.Comment: No LaTeX source; gzipped postscript text + 3 gzipped postscript figure

Structural changes in Cz-Si single crystals irradiated with high-energy electrons from data of high-resolution X-ray diffractometry

Structural changes in silicon single crystals irradiated with high-energy electrons (Е = 18 MeV) were studied. The peculiarities of diffraction reflection curve behaviour and changes in the profiles of isodiffusion lines in high-resolution reciprocal space maps (HR-RSMs) were found as a function of the radiation dose. The generalized dynamic theory of X-ray Bragg-diffraction in crystals comprising defects of several types (spherical and disc-shaped clusters as well as dislocation loops) and a damaged nearsurface layer was used for explanation

Interactions between Casein Kinase Iε (CKIε) and Two Substrates from Disparate Signaling Pathways Reveal Mechanisms for Substrate-Kinase Specificity

Members of the Casein Kinase I (CKI) family of serine/threonine kinases regulate diverse biological pathways. The seven mammalian CKI isoforms contain a highly conserved kinase domain and divergent amino- and carboxy-termini. Although they share a preferred target recognition sequence and have overlapping expression patterns, individual isoforms often have specific substrates. In an effort to determine how substrates recognize differences between CKI isoforms, we have examined the interaction between CKIepsilon and two substrates from different signaling pathways.CKIepsilon, but not CKIalpha, binds to and phosphorylates two proteins: Period, a transcriptional regulator of the circadian rhythms pathway, and Disheveled, an activator of the planar cell polarity pathway. We use GST-pull-down assays data to show that two key residues in CKIalpha's kinase domain prevent Disheveled and Period from binding. We also show that the unique C-terminus of CKIepsilon does not determine Dishevelled's and Period's preference for CKIepsilon nor is it essential for binding, but instead plays an auxillary role in stabilizing the interactions of CKIepsilon with its substrates. We demonstrate that autophosphorylation of CKIepsilon's C-terminal tail prevents substrate binding, and use mass spectrometry and chemical crosslinking to reveal how a phosphorylation-dependent interaction between the C-terminal tail and the kinase domain prevents substrate phosphorylation and binding.The biochemical interactions between CKIepsilon and Disheveled, Period, and its own C-terminus lead to models that explain CKIepsilon's specificity and regulation

The Complete Genome Sequence of Thermoproteus tenax: A Physiologically Versatile Member of the Crenarchaeota

Here, we report on the complete genome sequence of the hyperthermophilic Crenarchaeum Thermoproteus tenax (strain Kra 1, DSM 2078(T)) a type strain of the crenarchaeotal order Thermoproteales. Its circular 1.84-megabase genome harbors no extrachromosomal elements and 2,051 open reading frames are identified, covering 90.6% of the complete sequence, which represents a high coding density. Derived from the gene content, T. tenax is a representative member of the Crenarchaeota. The organism is strictly anaerobic and sulfur-dependent with optimal growth at 86 degrees C and pH 5.6. One particular feature is the great metabolic versatility, which is not accompanied by a distinct increase of genome size or information density as compared to other Crenarchaeota. T. tenax is able to grow chemolithoautotrophically (CO2/H-2) as well as chemoorganoheterotrophically in presence of various organic substrates. All pathways for synthesizing the 20 proteinogenic amino acids are present. In addition, two presumably complete gene sets for NADH:quinone oxidoreductase (complex I) were identified in the genome and there is evidence that either NADH or reduced ferredoxin might serve as electron donor. Beside the typical archaeal A(0)A(1)-ATP synthase, a membrane-bound pyrophosphatase is found, which might contribute to energy conservation. Surprisingly, all genes required for dissimilatory sulfate reduction are present, which is confirmed by growth experiments. Mentionable is furthermore, the presence of two proteins (ParA family ATPase, actin-like protein) that might be involved in cell division in Thermoproteales, where the ESCRT system is absent, and of genes involved in genetic competence (DprA, ComF) that is so far unique within Archaea

Textural aspects of electrodeposition processes

Electrodeposition is the most widely used electrochemical surface treatment process for fabrication of functional and decorative coatings. Electrochemical and hydrodynamic parameters of the electrodeposition process and substrdte texture affect the formation of layers of texture and consequently, tbe pbysical and mechanical properties of coating associated with their anisotropy. The uniformity and structure of electroplated metals also strongly depend on the deposition kinetics (charge transfer reaction or mass transport conlrol), which detemlines the conditions of cathode deposit formation and consequently the crystallites orientation. The present work aims to investigate the influence of Cu substrate texture on developing of it in the copper coating electrodeposited under activation control as tbe simple model system for the first stage of thjs study. The texture analysis was performed on the basis of the back-renection pole figures and of ones with a constant information depth, measured by means of X-ray technique. The non-destructive method allowed to analyse the texture for different chosen areas of the deposited layer. The results show the existing texture inhomogenity. The texture of the substrate reveals a strong influence on the texture of the formed Cu layer in its near-interface area. As far as depositing from withdraws from the substrate surface, the texture proceeds to ,3 one component of axis type of (Ill)

Wpływ rasy oraz genu kodującego brązowe umaszczenie (TYRP-1) na barwę wełny i skóry u ras owcy żelaźnieńskiej i wrzosówki polskiej

Effect of the brown coat-coding gene (TYRP-1) on wool and skin color of Żelaźnieńska and Wrzosówka sheep. The study was conducted on randomly chosen ewes (Żelaźnieńska sheep – 93; Wrzosówka sheep - 133) during the shearing. Color of wool and skin was examined using device Chroma Mater CR-400 (Konica Minolta Sensing Inc., 2011). Taking into account the results of genotyping in order to the brown coat-coding gene (TYRP-1), 66 Żelaźnieska ewes and 74 Wrzosówka ewes were chosen to next stage of study where effect of the brown coat-coding gene (TYRP-1) on wool and skin color was assessed within breed and between breeds. Based on the results significant and highly significant differences in all color measurements of wool and skin between tested breeds were found, which should be connected with different wool color in each breed. However, there is striking difference in color of wool and skin regarding to a* color parameter, which were exactly opposite. It probably means that proportion of red or green color in skin is different than in wool. Differences in color values of wool depending on TYRP-1 gene genotypes were observed only for Wrzosówka sheep. The measurement of L* color parameter made on wool was highly significantly higher in the case of CC and CT genotypes in comparison to TT genotype. However, in the measurement of a* color parameter, the situation is opposite and homozygote TT had higher values compared to the others genotypes. No differences between wool and skin color of Żelaźnieńska sheep and no differences in skin color of Wrzosówka sheep were found. The results of studies on wool color, depending on genotype of the TYRP-1 gene in Wrzosówka sheep, make possibilities to conduct breeding work in order to develop standards for coat color for this breed.Wpływ rasy oraz genu kodującego brązowe umaszczenie (TYRP-1), na barwę wełny i skóry u owcy żelaźnieńskiej i wrzosówki polskiej. Badania przeprowadzono na maciorkach dorosłych i składał się z losowo wybranych w trakcie strzyży maciorek rasy żelaźnieńskiej (93) i wrzosówki (133). Wykonano pomiary wełny i skóry przy pomocy urządzenia Chroma Meter CR-400 (Konica Minolta Sensing Inc., 2011). Uwzględniając wyniki określania genotypu genu kodującego brązowe umaszczenie TYRP-1, wybrano do dalszych analiz 66 maciorek żelaźnieńskich i 74 rasy wrzosówka, na których oceniono wpływ genotypu TYRP-1 na cech barwy wełny i skóry w obrębie rasy i pomiędzy nimi. Na podstawie przeprowadzonych badań stwierdzono istotne bądź wysoko istotne różnice pomiędzy ocenianymi rasami owiec w zakresie wszystkich pomiarów barwy wełny i skóry, co należy wiązać z umaszczeniem u obu ras. Zastanawiający jest jednak fakt innego układu różnic w barwie wełny i skóry w odniesieniu do wartości pomiarów udziału barwy czerwonej „a”, które układały się dokładnie na odwrót w obu przypadkach. Oznacza to, że udział barwy czerwonej bądź zielonej w skórze jest inny jak w wełnie.Pomiar jasności barwy „L” wykonany na wełnie wykazał wysoko istotnie wyższe wartości w przypadku genotypów CC i CT w porównaniu do TT. Natomiast w przypadku pomiaru „a” sytuacja kształtowała się odwrotnie i to u osobników homozygotycznych TT osiągnęła wyższe wartości tej cechy w porównaniu do pozostałych. Brak zróżnicowania pomiarów barwy wełny i skóry u owcy żelaźnieńskiej oraz skóry u wrzosówki. Wyniki badań dotyczących rozkładu pomiarów barwy wełny w zależności od genotypu TYRP-1 u wrzosówki, stwarzają możliwość prowadzenia pracy hodowlanej w tym zakresie, co w konsekwencji może być wykorzystane w praktyce hodowlanej przy dążeniu do wypracowania skonsolidowanych standardów umaszczenia dla tej rasy