Role of the exchange and correlation potential into calculating the x-ray absorption spectra of half-metallic alloys: the case of Mn and Cu K-edge XANES in Cu2_2MnM (M = Al, Sn, In) Heusler alloys

This work reports a theoretical study of the x-ray absorption near-edge structure spectra at both the Cu and the Mn K-edge in several Cu$_2$MnM (M= Al, Sn and In) Heusler alloys. Our results show that {\it ab-initio} single-channel multiple-scattering calculations are able of reproducing the experimental spectra. Moreover, an extensive discussion is presented concerning the role of the final state potential needed to reproduce the experimental data of these half-metallic alloys. In particular, the effects of the cluster-size and of the exchange and correlation potential needed in reproducing all the experimental XANES features are discussed.Comment: 15 pages, 5 figure

Fundamental Pyrolysis Studies

Progress on the direct mass spectrometric sampling of pyrolysis products from wood and its constituents is described for the period from June 1982 to February 1983. A brief summary and references to detailed reports, of the qualitative demonstration of our approach to the study of the separated processes of primary and secondary pyrolysis is presented. Improvements and additions to the pyrolysis and data acquisition systems are discussed and typical results shown. Chief of these are a heated-grid pyrolysis system for controlled primary pyrolysis and a sheathed flame arrangement for secondary cracking studies. Qualitative results of the secondary cracking of cellulose, lignin, and wood are shown as are comparisons with the literature for the pyrolysis spectra of cellulose, lignin, and levoglucosan. 'Fingerprints' for a number of materials are shown, with spectra taken under carefully controlled conditions so that sensitivity calibrations for different compounds, now being determined, can be applied

Upwelling events, coastal offshore exchange, links to biogeochemical processes - Highlights from the Baltic Sea Sciences Congress at Rostock University, Germany, 19-22 March 2007

The Baltic Sea Science Congress was held at Rostock University, Germany, from 19 to 22 March 2007. In the session entitled"Upwelling events, coastal offshore exchange, links to biogeochemical processes" 20 presentations were given,including 7 talks and 13 posters related to the theme of the session.This paper summarises new findings of the upwelling-related studies reported in the session. It deals with investigationsbased on the use of in situ and remote sensing measurements as well as numerical modelling tools. The biogeochemicalimplications of upwelling are also discussed.Our knowledge of the fine structure and dynamic considerations of upwelling has increased in recent decades with the advent ofhigh-resolution modern measurement techniques and modelling studies. The forcing and the overall structure, duration and intensity ofupwelling events are understood quite well. However, the quantification of related transports and the contribution to the overall mixingof upwelling requires further research. Furthermore, our knowledge of the links between upwelling and biogeochemical processes is stillincomplete. Numerical modelling has advanced to the extent that horizontal resolutions of c. 0.5 nautical miles can now be applied,which allows the complete spectrum of meso-scale features to be described. Even the development of filaments can be describedrealistically in comparison with high-resolution satellite data.But the effect of upwelling at a basin scale and possible changes under changing climatic conditions remain open questions

Гельмінтози диких копитних тварин: гельмінтофауна. Поширення та особливості профілактики

Ensuring the veterinary and sanitary welfare of animals is essential. Parasitic diseases are especially dangerous for deer. Helminths cause considerable material damage to deer farms, mainly decreasing the productive, trophy, and marketable qualities of animals. This article studies the distribution and features of preventing helminthiasis of wild ungulates. In ungulate populations settled in new ecological conditions, helminth fauna formation depends on many factors. In particular, this process is influenced by the correct selection of the settlement area, the physiological state of animals, the organization of animal feeding, medical and preventive measures, etc. Among the main measures for preventing helminthiasis in deer in the conditions of their semi-free keeping (farms, aviaries), those that reduce the possibility of infection of animals with parasites common to domestic animals are also vital. Wild animals are much more often infected with helminths of domestic animals, and the most dangerous parasitosis for them are fasciolosis, parafasciolopsosis, cysticercosis, trichostrongylidosis of ruminants. Infection with nematodes Capillaria spp. is characteristic exclusively for red deer, and the intensity of infestation is higher for this species of ruminant ungulates in free-range conditions. According to some researchers, mecystocirosis and strongyloidosis are among the most common helminthiasis in deer, the infection with pathogens of which is 74.5 and 73.3 %, respectively. Parafasciolopsoses (IE – 5.9 %), nematodirus (IE – 5.9 %), and paramphistomatids (IE – 2.8 %) are found somewhat less often. Thus, the study of helminth fauna, the development and implementation of adequate means, and methods of prevention of parasites in wild animals acquire considerable relevance. There are several ways to prevent helminthiasis in hunting and aviary deer farms; when examining the land and choosing an area for aviaries for deer, a helminthological assessment should be taken into account; it is mandatory to examine animals for helminthiasis (parasitocenoses) and carry out deworming of all imported animals; carry out annual disinfestation of feeders, watering holes, places for feeding, protective structures for animals; it is crucial to rationally place biotechnical facilities in areas safe from parasitosis; infected animals with characteristic clinical signs of the disease must be culled. There is quite a lot of information in the available literature regarding the group method of using anthelmintics for deer.Важливим є забезпечення ветеринарно-санітарного благополуччя тварин. Особливо небезпечним для оленів є паразитарні захворювання. Гельмінти завдають оленячим фермам значних матеріальних збитків, які в основному складаються із зниження продуктивних, трофейних та товарних якостей тварин. Дана стаття присвячена вивченню поширенню та особливостям профілактики гельмінтозів диких копитних тварин. У популяціях копитних, поселених в нові екологічні умови, процес формування гельмінтофауни залежить від багатьох чинників. Зокрема, на цей процес впливають правильність вибору території розселення, фізіологічний стан тварин і організація підгодівлі тварин, лікувально-профілактичні заходи тощо. Серед основних заходів профілактики гельмінтозів в оленів в умовах їх напіввільного утримання (ферми, вольєри) важливими є такі, що забезпечують зниження можливості зараження тварин паразитами, які є спільними і для домашніх тварин. Дикі тварини набагато частіше заражаються гельмінтами свійських тварин, і найбільш небезпечними паразитозами для них є фасціольоз, парафасціолопсоз, цистицеркози, трихостронгілідози жуйних. Зараженість нематодами Capillaria spp. є характерною виключно лише для благородного оленя, причому інтенсивність інвазії є вищою для цього виду жуйних копитних тварин в умовах вільного утримання. На думку окремих дослідників, до найпоширеніших гельмінтозів у оленів належать мецистоцироз і стронгілоїдоз, зараженість збудниками яких становить 74,5 і 73,3 % відповідно. Дещо рідше виявляють парафасціолопсози (ІЕ – 5,9 %), нематодіруси (ІЕ – 5,9 %) і парамфістоматиди (ІЕ – 2,8 %). Таким чином вивчення гельмінтофауни, розробка і впровадження ефективних засобів і способів профілактики паразитів у диких тварин набуває значної актуальності. Є кілька шляхів профілактики гельмінтозів у мисливських і вольєрних оленячих господарствах, а саме: при дослідженні угідь і виборі території під вольєри для оленів слід враховувати гельмінтологічну оцінку; обов’язково досліджувати тварин на гельмінтози (паразитоценози) і проводити дегельмінтизацію всіх завезених тварин; проводити щорічну дезінвазію годівниць, водопоїв, місць для годівлі, захисних для тварин споруд; важливо раціонально розміщувати біотехнічні споруди у безпечних по паразитозах угіддях; в обов’язковому порядку слід вибраковувати заражених звірів, що мають характерні клінічні ознаки захворювання. У доступній літературі доволі багато інформації щодо групового методу застосування антигельмінтиків оленям

Studies of viomycin, an anti-tuberculosis antibiotic: Copper(II) coordination, DNA degradation and the impact on delta ribozyme cleavage activity

Viomycin is a basic peptide antibiotic, which is among the most effective agents against multidrug-resistant tuberculosis. In this paper we provide the characteristics of its acid base properties, coordination preferences towards the Cu(II) ions, as well as the reactivity of the resulting complexes against plasmid DNA and HDV ribozyme. Careful coordination studies throughout the wide pH range allow for the characterisation of all the Cu(II)-viomycin complex species. The assignment of proton chemical shifts was achieved by NMR experiments, while the DTF level of theory was applied to support molecular structures of the studied complexes. The experiments with the plasmid DNA reveal that at the physiological levels of hydrogen peroxide the Cu(II)-viomycin complex is more aggressive against DNA than uncomplexed metal ions. Moreover, the degradation of DNA by viomycin can be carried out without the presence of transition metal ions. In the studies of antigenomic delta ribozyme catalytic activity, viomycin and its complex are shown to modulate the ribozyme functioning. The molecular modelling approach allows the indication of two different locations of viomycin binding sites to the ribozyme

Magnetic phase separation in ordered alloys

We present a lattice model to study the equilibrium phase diagram of ordered alloys with one magnetic component that exhibits a low temperature phase separation between paramagnetic and ferromagnetic phases. The model is constructed from the experimental facts observed in Cu$_{3-x}$AlMn$_{x}$ and it includes coupling between configurational and magnetic degrees of freedom which are appropriated for reproducing the low temperature miscibility gap. The essential ingredient for the occurrence of such a coexistence region is the development of ferromagnetic order induced by the long-range atomic order of the magnetic component. A comparative study of both mean-field and Monte Carlo solutions is presented. Moreover, the model may enable the study of the structure of the ferromagnetic domains embedded in the non-magnetic matrix. This is relevant in relation to phenomena such as magnetoresistance and paramagnetism.Comment: 12 pages, 11 figures, accepted in Phys. Rev.

Mitochondrial targeting adaptation of the hominoid-specific glutamate dehydrogenase driven by positive Darwinian selection

Many new gene copies emerged by gene duplication in hominoids, but little is known with respect to their functional evolution. Glutamate dehydrogenase (GLUD) is an enzyme central to the glutamate and energy metabolism of the cell. In addition to the single, GLUD-encoding gene present in all mammals (GLUD1), humans and apes acquired a second GLUD gene (GLUD2) through retroduplication of GLUD1, which codes for an enzyme with unique, potentially brain-adapted properties. Here we show that whereas the GLUD1 parental protein localizes to mitochondria and the cytoplasm, GLUD2 is specifically targeted to mitochondria. Using evolutionary analysis and resurrected ancestral protein variants, we demonstrate that the enhanced mitochondrial targeting specificity of GLUD2 is due to a single positively selected glutamic acid-to-lysine substitution, which was fixed in the N-terminal mitochondrial targeting sequence (MTS) of GLUD2 soon after the duplication event in the hominoid ancestor ~18–25 million years ago. This MTS substitution arose in parallel with two crucial adaptive amino acid changes in the enzyme and likely contributed to the functional adaptation of GLUD2 to the glutamate metabolism of the hominoid brain and other tissues. We suggest that rapid, selectively driven subcellular adaptation, as exemplified by GLUD2, represents a common route underlying the emergence of new gene functions

Technology of protection and control of printed products using application programs of digital introscopy

The article presents the basics of the method of correlation spatial-frequency filtering of maps of phase distributions of polyethylene films. Using the method of statistical analysis of the structure of spatial-frequency filtered polarization mapsof polymer films, a set of methods and criteria for diagnosingchanges in the birefringence of packaging materials has beensubstantiated and tested.У статті наведено основи методу кореляційної просторово-частотної фільтрації карток фазових розподілів поліетиленових плівок. Використовуючи метод статистичного аналізу структури просторово-частотних фільтрованих поляризаційних карт полімерних плівок, обґрунтовано та апробовано комплекс методів та критеріїв діагностики зміни двопроменеломлення пакувальних матеріалів

Applied computer polarization-singular analysis of polymer packaging materials

This manuscript discusses the development of a singular approach to analyzing polarization-inhomogeneous laser fields in order to improve the manufacturing technology of packaging printing products. The analysis is based on a model approach, which represents polyethylene polymer film networks as a two-component amorphous-crystallite matrix.У статті описана розробка та обґрунтування принципів сингулярного підходу до аналізу поляризаційно-неоднорідних лазерних полів з метою вдосконалення технології виготовлення пакувальної поліграфічної продукції. У статті наведено детальні теоретичні пояснення, які допомагають зрозуміти механізми формування поляризаційно- сингулярних структур у полімерних плівках