Genomics and proteomics of deleted ovine CSN1S11I

Ovine α_s1-casein (CSN1S1) allele I (CSN1S1¹I) was characterized at the molecular genetic and protein level. Sequencing of CSN1S1 cDNA and mature protein showed the absence of exon 7 from CSN1S1¹I in comparison with the C″ genetic variant of the C phenotype. This allelic aberration is correlated with a sequence difference in 5′-splice donor sequence of intron 7 (g.656T > A), leading to upstream skipping of exon 7. Consequently mRNA sequence of ovine CSN1S1¹I is 24 bp shorter than complete coding sequence leading to an abbreviation of eight amino acids in the mature protein, resulting in a lower degree of phosphorylation in comparison with CSN1S1¹C″. However CSN1S1¹I was expressed at a quantitative level similar to that for the C″ reference variant. Using amplified created restriction site polymerase chain reaction, a DNA-based test for identification of CSN1S1¹I was developed. Altogether six nucleotide substitutions were identified within intron 6 and intron 7 of CSN1S1 variants, forming three different haplotypes.     

Establishing baseline levels of trace elements in blood and skin of bottlenose dolphins in Sarasota Bay, Florida: implications for non-invasive monitoring

Several major unusual mortality events occurring in recent years have increased the level of concern for the health of bottlenose dolphin populations along the United States Atlantic and Gulf of Mexico coasts. Trace element concentrations were examined in a population of free-ranging dolphins in Sarasota Bay, Florida, in order to develop a benchmark for future comparisons within and between populations. Whole blood (n=51) and skin (n=40) samples were collected through capture and release health assessment events during 2002-2004. Samples were analyzed for Al, V, Cr, Mn, Cu, Zn, As, Se, Rb, Sr, Mo, Cd, and Pb by inductively coupled plasma mass spectrometry (ICPMS) and Hg via atomic fluorescence spectrometry (AFS). Trace element concentrations (wet mass) in skin were 2 to 45 times greater than blood, except Cu was approximately 1.5 times higher in blood. Statistically strong correlations (p<0.05) were found for V, As, Se, Rb, Sr, and Hg between blood and skin demonstrating that these tissues can be used as effective non-lethal monitoring tools. The strongest correlation was established for Hg (r=0.9689) and concentrations in both blood and skin were above the threshold at which detrimental effects are observed in other vertebrate species. Female dolphins had significantly greater Hg concentrations in blood and skin and Pb concentrations in skin, relative to males. Calves exhibited significantly lower V, As, and Hg concentrations in blood and V and Hg concentrations in skin, relative to other age classes. Rubidium and Cu concentrations in skin were greatest in subadults and calves, respectively. In blood, V, Zn, and As concentrations were significantly greater in winter, relative to summer, and the opposite trend was observed for Rb and Sr concentrations. In skin, Cu and Zn concentrations were significantly greater in winter, relative to summer, and the opposite trend was observed for Mn, Rb, Cd, and Pb concentrations. The baseline concentrations and trends established in this study will serve as a benchmark for comparison and aid in sampling design for future monitoring of this population and other coastal bottlenose dolphin populations.     

Development of Nano-Composite Microstructures in ZrO2-Al2O3 via the Solution Precursor Method

Aqueous mixtures of zirconium acetate and aluminum nitrate were pyrolyzed and crystallized to form a metastable solid solution, Zr_{1- x} Al _x O_{2− x /2} ( x < 0.57). The initial, metastable phase partitions at higher temperatures to form two metastable phases, viz., t −ZrO₂+γ-Al₂O₃ with a nano-scale microstructure. The microstructural observations associated with the γ- →α-Al₂O₃ phase transformation in the t -ZrO₂ matrix are reported for compositions containing 10, 20, and 40 mol% A1₂O₃. During this phase transformation, the α-Al₂O₃ grains take the form of a colony of irregular, platelike grains, all with a common crystallographic orientation. The plates contain ZrO₂ inclusions and are separated by ZrO₂ grains. The volume fraction of A1₂O₃ and the heat treatment conditions influence the final microstructure. At lower volume fractions of A1₂O₃, the colonies coarsen to single, irregular plates, surrounded by polycrystalline ZrO₂. Interpenetrating microstructures produced at high volume fractions of A1₂O₃ exhibit very little grain growth for periods up to 24 h at 1400°C.     

Occurrence of methyl triclosan, a transformation product of the bactericide triclosan, in fish from various lakes in Switzerland

The bactericide triclosan and methyl triclosan, an environmental transformation product thereof, have been previously detected in lakes and a river in Switzerland. Both compounds are emitted via wastewater treatment plants (WWTPs), with methyl triclosan probably being formed by biological methylation. Passive sampling with semi-permeable membrane devices (SPMDs) showed the presence of methyl triclosan in some lakes, suggesting some potential for bioaccumulation of the compound. In this study, we report the presence of methyl triclosan in fish (white fish, Coregonus sp.; roach, Rutilus rutilus) from various lakes in Switzerland receiving inputs from WWTPs. Identification of the compound was based on mass spectral (MS) evidence including MS/MS data. The concentrations of methyl triclosan in the fish were up to 35 ng g(-1) on a wet weight basis and up to 365 ng g(-1) on a lipid basis with concentrations in a relatively narrow range for fish from the same lake (Thunersee, 4-6 ng g(-1); Zürichsee, 32-62 ng g(-1); Pf?ffikersee, 43-56 ng g(-1); Greifensee, 165-365 ng g(-1), lipid basis). No methyl triclosan (<1 ng g(-1), lipid basis) was detected in fish (lake trout, Salmo trutta) from a remote lake in Sweden (H?bberstj?rnen) and in fish (roach) from a small lake in Switzerland with no input from WWTPs (Hüttnersee, <2-<5 ng g(-1), lipid basis). The concentrations of methyl triclosan in fish correlated (r2 = 0.85) with the ratio of population in the watershed to water throughflow of the lakes (P/Q ratio), which is considered to be a measure for the domestic burden from WWTPs to a lake. Passive sampling with SPMDs confirmed the presence of methyltriclosan in lakes and a river (Zürichsee and Greifensee; Limmat) but not in a remote mountain lake (J?risee) and in Hüttnersee. The bioconcentration factor (BCF) of methyl triclosan estimated from the fish data and SPMD-derived water concentrations was in the order of 1-2.6 x 10(5) (lipid basis) and thus in the range of other persistent organic pollutants. SPMDs were found to be reliable for monitoring low concentrations of methyl triclosan in surface water. Methyl triclosan appears to be a suitable marker for WWTP-derived lipophilic contaminants in the aquatic environment and fish.     

Optimization of photonic crystal structures

We report on the numerical structural optimization of two-dimensional photonic crystal (PhC) power dividers by using two different classes of optimization algorithms, namely, a modified truncated Newton (TN) gradient search as deterministic local optimization scheme and an evolutionary optimization representing the probabilistic global search strategies. Because of the severe accuracy requirements during optimization, the proper PhC device has been simulated by using the multiple-multipole program that is contained in the MaX-1 software package. With both optimizer classes, we found reliable and promising solutions that provide vanishing power reflection and perfect power balance at any specified frequency within the photonic bandgap. This outcome is astonishing in light of the discrete nature inherent in the underlying PhC structure, especially when the optimizer is allowed to intervene only within a very small volume of the device. Even under such limiting constraints structural optimization is not only feasible but has proven to be highly successful.     

Neodymium:YLF lasers at 1053 nm passively mode locked with a saturable Bragg reflector

We present the results obtained from three different setups of stable, diode-laser-pumped Nd:YLF lasers that operate in the TEM00 mode at 1053 nm and are passively mode locked by a saturable Bragg reflector. We obtained pulse widths tailored between approximately 70 ps and approximately 4 ns by using intracavity etalons of various thicknesses. With a maximum output power of 680 mW, we achieved an optical efficiency of 23%.     

Regulation of inorganic pigments used in plastics

Review of the government regulations of the major inorganic pigments used in plastics particularly of the metals involved in formation of color.     

Solid phase extraction and removal of 2,4-dichlorophenol from aqueous samples using magnetic graphene nanocomposite

A magnetic graphene nanocomposite (Fe₃O₄-GNC) was prepared and used for the solid phase extraction (SPE) and removal of 2,4-dichlorophenol from aqueous solutions. The physicochemical properties were investigated using SEM, EDX, FTIR, and TGA. Different factors affecting sorption capacity were studied systematically. Results for kinetics studies revealed that 2,4-dichlorophenol sorption followed pseudo-second-order kinetics and the q_e value (987.45 mg/g) was in close agreement with experimental value (1000 mg/g). Thermodynamic study showed that the sorption is endothermic (?Hº = +56.116 kJ/mol) and spontaneous. The desorption studies were carried out for the reusability and extraction of 2,4-dichlorophenol from aqueous samples and 94% recoveries were obtained. The method was found feasible for the removal and preconcentration of trace analysis of 2,4-dichlorophenol in environmental water samples.     

Proof Pearl: Mechanizing the Textbook Proof of Huffman’s Algorithm

Huffman’s algorithm is a procedure for constructing a binary tree with minimum weighted path length. Our Isabelle/HOL proof closely follows the sketches found in standard algorithms textbooks, uncovering a few snags in the process. Another distinguishing feature of our formalization is the use of custom induction rules to help Isabelle’s automatic tactics, leading to very short proofs for most of the lemmas. This work was supported by the DFG grant NI 491/11-1.