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Various Environments (various + environment)
Selected AbstractsRetrospective clinical study of 90 avulsed permanent teeth in 58 childrenDENTAL TRAUMATOLOGY, Issue 6 2008Vasileios Tzigkounakis We analyzed the documentations of a sample of patients containing 57 children who had a total of 90 avulsed teeth and were treated in Dentistry Department of Medical Faculty in Pilsen, Czech Republic, in the years between 1995 and 2005. We discovered that most frequently the children experience dental avulsion in the age between 8 and 11 years old, the most affected teeth are the upper central incisors and the most frequent causes are sports and games which are very common in these ages, in various environments, like schools, sport fields and home. The majority of the children were transferred to the Dentistry Department either quite long after the avulsion incident and without the avulsed teeth, or with the avulsed teeth which were carried in an inappropriate transport medium, indicating that there is insufficient knowledge of adult people, especially the ones who are in daily contact with children, on how to provide first aid in cases of dental avulsion. [source] A new genetic algorithm with diploid chromosomes using probability decoding for adaptation to various environmentsELECTRONICS & COMMUNICATIONS IN JAPAN, Issue 8 2010Manabu Kominami Abstract This paper proposes a new diploid operation technique using probability for function optimization in nonstationary environments and describes a feature of diploid genetic algorithms (GAs). The advantage of the technique over previous diploid GAs is that one genotype is transformed into many phenotypes based on probability. This transformation is not made at random. It has a certain range of probabilities. Each individual has a range. The range allows adaptation to various environments. The technique allows genes to give a probabilistic representation of dominance, and can maintain the diversity of individuals. The experimental results show that the technique can adapt to severe environmental changes where previous diploid GAs cannot adapt. This paper shows that the technique can find optimum solutions with high probability and that the distribution of individuals changes when the environment changes. In addition, by comparing the proposed diploid GA with a haploid GA whose chromosome is twice the length, the features of the diploid are described. © 2010 Wiley Periodicals, Inc. Electron Comm Jpn, 93(8): 38,46, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecj.10097 [source] Survival of human enteric viruses in the environment and foodFEMS MICROBIOLOGY REVIEWS, Issue 4 2004Artur Rze Abstract Human enteric pathogenic viruses can enter the environment through discharge of waste materials from infected persons, and be transmitted back to susceptible persons to continue the cycle of disease. Contamination of food with viruses may also promote disease outbreaks. A number of studies have investigated the survival characteristics of several enteric viruses in various environments and foodstuffs, to help explain the transmissibility of these pathogens. This review deals with published work on enteric virus survival on fomites, and in waters, soil, and foods; the results of these studies have illustrated the robust survival of viruses in these environments. Much information is lacking, however, especially for foodstuffs and soils, and no detailed information is available concerning the survival of noroviruses, the most significant foodborne type. [source] Ribosomal RNA gene fragments from fossilized cyanobacteria identified in primary gypsum from the late Miocene, ItalyGEOBIOLOGY, Issue 2 2010G. PANIERI Earth scientists have searched for signs of microscopic life in ancient samples of permafrost, ice, deep-sea sediments, amber, salt and chert. Until now, evidence of cyanobacteria has not been reported in any studies of ancient DNA older than a few thousand years. Here, we investigate morphologically, biochemically and genetically primary evaporites deposited in situ during the late Miocene (Messinian) Salinity Crisis from the north-eastern Apennines of Italy. The evaporites contain fossilized bacterial structures having identical morphological forms as modern microbes. We successfully extracted and amplified genetic material belonging to ancient cyanobacteria from gypsum crystals dating back to 5.910,5.816 Ma, when the Mediterranean became a giant hypersaline brine pool. This finding represents the oldest ancient cyanobacterial DNA to date. Our clone library and its phylogenetic comparison with present cyanobacterial populations point to a marine origin for the depositional basin. This investigation opens the possibility of including fossil cyanobacterial DNA into the palaeo-reconstruction of various environments and could also be used to quantify the ecological importance of cyanobacteria through geological time. These genetic markers serve as biosignatures providing important clues about ancient life and begin a new discussion concerning the debate on the origin of late Miocene evaporites in the Mediterranean. [source] Biogeochemistry of microbial mats under Precambrian environmental conditions: a modelling studyGEOBIOLOGY, Issue 2 2005E. K. HERMAN ABSTRACT Microbial mats have arguably been the most important ecosystem on Earth over its 3.5 Gyr inhabitation. Mats have persisted as consortia for billions of years and occupy some of Earth's most hostile environments. With rare exceptions (e.g. microbial mats developed on geothermal springs at Yellowstone National Park, USA), today's mats do not exist under conditions analogous to Precambrian habitats with substantially lower oxygen and sulphate concentrations. This study uses a numerical model of a microbial mat to investigate how mat composition in the past might have differed from modern mats. We present a numerical model of mat biogeochemistry that simulates the growth of cyanobacteria (CYA), colourless sulphur bacteria (CSB), and purple sulphur bacteria (PSB), with sulphate-reducing bacteria (SRB) and heterotrophic bacteria represented by parameterized sulphate reduction rates and heterotrophic consumption rates, respectively. Variations in the availability of light, oxygen, sulphide, and sulphate at the upper boundary of the mat are the driving forces in the model. Mats with remarkably similar biomass and chemical profiles develop in models under oxygen boundary conditions ranging from 2.5 × 10,13 to 0.25 mm and sulphate boundary concentrations ranging from 0.29 to 29 mm, designed to simulate various environments from Archean to modern. The modelled mats show little sensitivity to oxygen boundary conditions because, independent of the overlying oxygen concentrations, cyanobacterial photosynthesis creates similar O2 concentrations of 0.45,0.65 mm in the upper reaches of the mat during the photoperiod. Varying sulphate boundary conditions have more effect on the biological composition of the mat. Sulphide generated from sulphate reduction controls the magnitude and distribution of the PSB population, and plays a part in the distribution of CSB. CSB are the most sensitive species to environmental change, varying with oxygen and sulphide. [source] Rennin-like milk coagulant enzyme produced by a local isolate of MucorINTERNATIONAL JOURNAL OF DAIRY TECHNOLOGY, Issue 4 2003Z A Tubesha Among 20 isolates of Mucor isolated from various environments in Jordan and found to produce a rennin-like acid protease, known as Mucor rennin-like enzyme (MRE), Mucor J20 was found to produce the highest level of MRE. The optimum incubation conditions for enzyme production in a fortified wheat bran mixture using solid-state fermentation were 3,4 days at 30°C. The highest MRE activity (185,200 rennin units or RU) was produced in a medium containing wheat bran and lentil straw (1 : 1 w/w) moistened with whey, and incubated in clay pots at 30°C for 4 days. A slightly lower activity value (178 RU) was found when using a mineral salt solution or distilled water instead of whey, or when using wheat bran alone with whey. At pH 4, the MRE retained its complete activity (100%) for 6 weeks at 5°C and 10°C, and for 3 and 2 weeks at 20°C and 30°C, respectively. After heating at 60°C for 10 min, the enzyme lost its activity at all pH levels used (pH 2,8). The crude extract of MRE was successfully applied in the manufacture of a cheese curd. [source] Use of vibrational spectroscopy to study protein and DNA structure, hydration, and binding of biomolecules: A combined theoretical and experimental approachINTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY, Issue 5 2006K. J. Jalkanen Abstract We report on our work with vibrational absorption, vibrational circular dichroism, Raman scattering, Raman optical activity, and surface-enhanced Raman spectroscopy to study protein and DNA structure, hydration, and the binding of ligands, drugs, pesticides, or herbicides via a combined theoretical and experimental approach. The systems we have studied systematically are the amino acids (L -alanine, L -tryptophan, and L -histidine), peptides (N -4271 acetyl L -alanine N,-methyl amide, N -acetyl L -tryptophan N,-methyl amide, N -acetyl L -histidine N,-methyl amide, L -alanyl L -alanine, tri- L -serine, N -acetyl L -alanine L -proline L -tyrosine N,-methyl amide, Leu-enkephalin, cyclo-(gly- L -pro)3, N -acetyl (L -alanine)nN,-methyl amide), 3-methyl indole, and a variety of small molecules (dichlobenil and 2,6-dochlorobenzamide) of relevance to the protein systems under study. We have used molecular mechanics, the SCC-DFTB, SCC-DFTB+disp, RHF, MP2, and DFT methodologies for the modeling studies with the goal of interpreting the experimentally measured vibrational spectra for these molecules to the greatest extent possible and to use this combined approach to understand the structure, function, and electronic properties of these molecules in their various environments. The application of these spectroscopies to biophysical and environmental assays is expanding, and therefore a thorough understanding of the phenomenon from a rigorous theoretical basis is required. In addition, we give some exciting and new preliminary results which allow us to extend our methods to even larger and more complex systems. The work presented here is the current state of the art to this ever and fast changing field of theoretical spectroscopic interpretation and use of VA, VCD, Raman, ROA, EA, and ECD spectroscopies. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2006 [source] The nature of the Sloan Digital Sky Survey galaxies in various classes based on morphology, colour and spectral features , III.MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Issue 4 2010Environments ABSTRACT We present a study on the environments of the Sloan Digital Sky Survey (SDSS) galaxies divided into fine classes based on their morphology, colour and spectral features. The SDSS galaxies are classified into early-type and late-type; red and blue; passive, H ii, Seyfert and low-ionization nuclear emission-line region (LINER), which returns a total of 16 fine classes of galaxies. We estimate the local number density, target-excluded local luminosity density, local colour, close pair fraction and the luminosity and colour of the brightest neighbour, which are compared between the fine classes comprehensively. The morphology,colour class of galaxies strongly depends on the local density, with the approximate order of high-density preference: red early-type galaxies (REGs); red late-type galaxies (RLGs); blue early-type galaxies (BEGs) and blue late-type galaxies (BLGs). We find that high-density environments (like cluster environments) seem to suppress active galactic nucleus activity. The pair fraction of H ii REGs does not show a statistically significant difference from that of passive REGs, while the pair fraction of H ii BLGs is smaller than that of non-H ii BLGs. H ii BLGs show obvious double (red + blue) peaks in the distribution of the brightest neighbour colour, while red galaxies show a single red peak. The brightest neighbours of Seyfert BLGs tend to be blue, while those of LINER BLGs tend to be red, which implies that the difference between Seyfert and LINER may be related to the pair interaction. Other various environments of the fine classes are investigated, and their implications for galaxy evolution are discussed. [source] A new method to quantify crazing in various environmentsPOLYMER ENGINEERING & SCIENCE, Issue 3 2001Stephen B. Clay A new technique to quantify the rate of change of craze density in stressed transparent polymeric plates of polycarbonate was developed. The samples are placed under a creep load in a controlled temperature and humidity environment, during which the craze density is measured with a reflective imaging system at a defined rate. It has been shown that this unique method for crazy detection and quantification has sufficient repeatability to generate statistically acceptable data, obeying currently used, the method described in the present work is an in-situ, quantitative, non-subjective, direct measurement of craze density. [source] | ||||||||||