Effect of the Compositions of Sample and Polymer Sorbents on the Extraction of Volatile Compounds by Solid-Phase Microextraction

A comparative study was performed by solid phase microextraction and capillary gas chromatography to establish the ability of four polymer sorbents of different compositions to extract and concentrate volatile organic compounds from the gas phase above an aqueous solution. All polymer sorbents sorbed nonpolar monoterpene hydrocarbons via a cooperative mechanism with almost equal and high efficiency. Sorbents based on polymethyl disiloxane and its mixture with divinylbenzene were more effective in extracting acetates and sesquiterpenes. As the concentration of these compounds in the gas phase increased, their binding by sorbents decreased. It was found that the determination of polar compounds depended on the presence of a solvent in the system. Compounds that are highly soluble in water (alcohols, ketones, etc.) had low coefficients of distribution between gas and water phases. Consequently, their sorption to any of the polymer sorbents was negligible. In the absence of the solvent, the degree of their extraction from the gas phase above the sample was high. It was shown that the actual composition of compounds in the initial mixture of essential oils could significantly differ from their composition in the gas phase. This method is convenient and informative for the purpose of studying the composition of volatile compounds in the gas phase that determine the flavor of the product.     

Associations between PRLR/AluI gene polymorphism with reproductive,growth, and meat traits in pigs

The aim of this study was to determine the associations between genotypes of the prolactin receptor gene (PRLR) and reproductive, growth, and meat traits in pigs. Genetic groups of sows were used: Large White (LW), Danish Landrace (LD), and Landrace × Yorkshire × Duroc hybrids (L × Y × D). Reproductive traits studied were the total number of born (TNB) and the number born alive (NBA). The growth traits were the number of days to 100 kg and the average daily gains (ADG). The meat traits were the average backfat thickness (BFT), half carcass weight (HCW), area of M. longissimus dorsi (MLT), and lean meat content (LM). The polymorphism was detected using the polymerase chain reaction-restriction fragment-length polymorphism (PCR-RFLP) method. It was found that the genotype BB is associated with the best NBA. In sows LD, the AB genotype is associated with best number of days to 100 kg; in hybrids L × Y × D, the AA genotype is associated with better meat traits as compared to the genotype BB.     

Frequency of the F508 deletion in cystic fibrosis patients from the European part of the USSR

Summary The frequency of the F508 deletion (F508) has been analyzed in 189 cystic fibrosis (CF) patients from the European part of the USSR, viz. 127 nothern Slavonians (Leningrad region), 30 southern Slavonians (the Ukraine), 10 central Slavonians (Moscow region), 14 Moldavians (Kishenev region) and 8 Lithuanians (Vilnius region). The distribution of CF⁺ chromosomes with and without F508 varied significantly in the different ethnic groups studied and correlated with the clinical manifestation of CF. The overall frequency of F508 in Slavonian patients is equal to 62.5%, approximately 90% of them being heterozygous or homozygous for this mutation. The frequency of the deletion among 99 Slavonian patients with severe disease manifestation (pancreatic insufficiency, PI) is equal to 67.5%, only 12 patients having pancreatic sufficiency (PS, 17.5%). The highest value of F508 (77.4%) is registered in PI/CF patients of the southern Slavonian group; it is much less frequent (about 57%) in relevant groups of Slavonians from the northern and central parts of the country. Unusually low frequencies (24% and 26%) of F508 are detected in a few samples of Lithuanian and Moldavian CF patients, respectively. All F508⁺CF-chromosomes of Slavonian origin are associated with haplotypes 2.2.2. defined by the restriction fragment length polymorphism sites KM19/PstI, CS.7/Hin6I and MP6d-9/MspI, although a high proportion (about 25%) of unknown mutations is associated with the same haplotype. Haplotype B (allele 1XV2c/TaqI; allele 2 KM19/PstI) accounts for 91% of F508⁺CF chromosomes. Our data are consistent with the hypothesis of a single origin and subsequent diffusion of this major CF mutation; however, its interpopulational dissemination in Eastern Europe does not follow the suggested south-east to north-west gradient in Western Europe. The significance of these data for prenatal diagnosis and carrier screening of CF mutations is briefly discussed.     

A new method for hybrid seed production based on cytoplasmic male sterility combined with a lethal gene and a female sterile pollenizer in Capsicum annuum L.

Summary A new improved method for hybrid seed production was successfully tested. This method is based on using a cytoplasmic male sterile line possessing a lethal gene with action that can be easily inhibited and a female sterile pollenizer. The lethal gene ensures 100% purity of the F₁ crop. The female sterile pollenizer provides a permanent abundant flowering with excess of pollen grains that leads to increased hybrid seed production without additional labour expenses. The described scheme is applicable for other crops as well.     

Optical Spectra of High-Temperature Superconductors

This paper complements our recent survey [1] of experimental and theoretical work on the optical spectra of high-temperature superconductors. The emphasis is laid on experiments involving single crystals and good textured ceramic samples. Data have been collected on chemically doped samples, as well as on samples in which carriers are created by photodoping. One of the most remarkable consequences is the observation of a photoinduced superconductivity and a phase separation of photoexcited carriers. The theory has offered a few main suggestions but they have all failed to produce the magic formula for understanding the optical response. Nevertheless, bipolaron models seem somewhat closer to reality. Future experimental, theoretical, and practical developments are considered.     

Development of a single tube 640-plex genotyping method for detection of nucleic acid variations on microarrays

Detection of DNA sequence variation is critical to biomedical applications, including disease genetic identification, diagnosis and treatment, drug discovery and forensic analysis. Here, we describe an arrayed primer extension-based genotyping method (APEX-2) that allows multiplex (640-plex) DNA amplification and detection of single nucleotide polymorphisms (SNPs) and mutations on microarrays via four-color single-base primer extension. The founding principle of APEX-2 multiplex PCR requires two oligonucleotides per SNP/mutation to generate amplicons containing the position of interest. The same oligonucleotides are then subsequently used as immobilized single-base extension primers on a microarray. The method described here is ideal for SNP or mutation detection analysis, molecular diagnostics and forensic analysis. This robust genetic test has minimal requirements: two primers, two spots on the microarray and a low cost four-color detection system for the targeted site; and provides an advantageous alternative to high-density platforms and low-density detection systems.     

Will cognitive enhancement create post‐persons? The use(lessness) of induction in determining the likelihood of moral status enhancement

The prospect of cognitive enhancement well beyond current human capacities raises worries that the fundamental equality in moral status of human beings could be undermined. Cognitive enhancement might create beings with moral status higher than persons. Yet, there is an expressibility problem of spelling out what the higher threshold in cognitive capacity would be like. Nicholas Agar has put forward the bold claim that we can show by means of inductive reasoning that indefinite cognitive enhancement will probably mark a difference in moral status. The hope is that induction can determine the plausibility of post‐personhood existence in the absence of an account of what the higher status would be like. In this article, we argue that Agar's argument fails and, more generally, that inductive reasoning has little bearing on assessing the likelihood of post‐personhood in the absence of an account of higher status. We conclude that induction cannot bypass the expressibility problem about post‐persons.