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Very High Degree (very + high_degree)
Selected AbstractsAn experimental study on the ripple,dune transitionEARTH SURFACE PROCESSES AND LANDFORMS, Issue 6 2001André Robert Abstract Flume experiments were conducted on different bed stages across the ripple,dune transition. As flow velocity increases, an initially flat bed surface (made of fairly uniform sandy material) is gradually transformed into a two-dimensional rippled bed. With further increase in velocity, two-dimensional ripples are replaced by irregular, linguoid ripples. As the average velocity necessary for the ripple,dune transition to occur is imposed on the bed surface, these non-equilibrium linguoid ripples are further transformed into larger, two-dimensional dunes. For each of these stages across the transition, a concrete mould of the bed was created and the flow structure above each fixed bed surface investigated. An acoustic Doppler velocimeter was used to study the flow characteristics above each bed surface. Detailed profiles were used along a transect located in the middle of the channel. Results are presented in the form of spatially averaged profiles of various flow characteristics and of contour maps of flow fields (section view). They clearly illustrate some important distinctions in the flow structure above the different bedform types associated with different stages during the transition. Turbulence intensity and Reynolds stresses gradually increase throughout the transition. Two-dimensional ripples present a fairly uniform spatial distribution of turbulent flow characteristics above the bed. Linguoid ripples induce three-dimensional turbulence structure at greater heights above the bed surface and turbulence intensity tends to increase steadily with height above bed surface in the wake region. A very significant increase in turbulence intensity and momentum exchange occurs during the transition from linguoid ripples to dunes. The turbulent flow field properties above dunes are highly dependent on the position along and above the bed surface and these fields present a very high degree of spatial variability (when compared with the rippled beds). Further investigations under natural conditions emphasizing sediment transport mechanisms and rates during the transition should represent the next step of analysis, together with an emphasis on quadrant analysis. Copyright © 2001 John Wiley & Sons, Ltd. [source] Is optimal foraging a realistic expectation in orb-web spiders?ECOLOGICAL ENTOMOLOGY, Issue 4 2009WILL EDWARDS Abstract 1.,Explanations for web relocation invoking optimal foraging require reliable differentiation between individual sites and overall habitat quality. We characterised natural conditions of resource variability over 20 days in artificial webs of the orb-web spider Gasteracantha fornicata to examine this requirement. 2.,Variability in catch success was high. Day-to-day catch success in 90% (18/20) catch sites fitted negative binomial distributions, whereas 10% fitted Poisson distributions. Considered across trap sites (overall habitat), variance in catch success increased proportionally faster than the mean (i.e. Taylor's Power Law, variance = 0.54mean1.764). 3.,We compared the confidence intervals for the expected cumulative catch in randomly drawn sequential samples from a frequency distribution representing the overall habitat (based on the parameters for Taylor's power law) and the frequency distribution of expected cumulative catch within each individual catch site [via randomisation based on the mean and negative binomial exponent (k)]. 4.,In all cases and across all sample sizes, median values for the power to differentiate habitat and catch sites never exceeded 0.2, suggesting that principles involved in optimal foraging, if operating, must be accompanied by a very high degree of uncertainty. 5.,Under conditions of high resource variability, many days must be spent in a single catch site if movement decisions are based on an ability to differentiate current catch site from overall habitat. Empirical evidence suggests this is never met. This may explain why proximal mechanisms that illicit quickly resolved behavioural responses have been more successful in describing web relocation patterns than those associated with optimal foraging. [source] Patterns of phenotypic and genetic variability show hidden diversity in Scottish Arctic charrECOLOGY OF FRESHWATER FISH, Issue 1 2007C. E. Adams Abstract,,, This study examined the degree and pattern of variability in trophic morphology in Arctic charr (Salvelinus alpinus L.) at three spatial scales: across 22 populations from Scotland and between and within two adjacent catchments (Laxford and Shin) in northern Scotland. In addition, the variability at six microsatellite loci between and within the Laxford and Shin systems was determined. Habitat use by charr differed significantly between populations. The pattern of variability in trophic morphology, known to influence foraging ability in charr, showed a very high degree of between-population variation with at least 52% of population pairs showing significant differences in head shape. Trophic morphology and genetic variation was also high over small geographical scales; variation being as high between charr from lakes within the same catchment, as between adjacent catchments. The pattern of both phenotypic and genotypic variation suggests a mosaic of variation across populations with geographically close populations often as distinct from each other as populations with much greater separation. Very low levels of effective migrants between populations, even within the same catchment, suggest that this variation is being maintained by very low straying rates between phenotypically and genetically distinct populations, even when there is no apparent barrier to movement. We conclude that the genetic and phenotypic integrity of charr populations across Scotland is high and that this adaptive radiation constitutes a ,hidden' element of diversity in northern freshwater systems. Two consequences of this are that the population (rather than the species) makes a more rational unit for the consideration of conservation strategies and that the habitat requirements and therefore management needs may differ significantly between populations. [source] Screening for resistance to Didymella bryoniae in rootstocks of melonEPPO BULLETIN, Issue 2 2000P. Trionfetti Nisini Glasshouse evaluations of rootstocks of melon for resistance to Didymella bryoniae were conducted on different cucurbits previously selected as resistant or partially resistant to race 1,2 of Fusarium oxysporum f. sp. melonis. Cucumis anguria, C. ficifolius, C. figarei, C. metuliferus, C. zeyheri and Benincasa hispida showed a very high degree of resistance to D. bryoniae both on leaves and stems. Among the commercial rootstocks, Cucurbita hybrids ELSI, ES 99-13, RS 841, displayed a similar level of resistance. Stem inoculation of three cucurbit species grafted with susceptible melon cv. Proteo determined the occurrence of limited symptoms, but the lesions remained confined in the rootstock not affecting the grafted plant. Cultivation of susceptible melon cultivars grafted on resistant rootstocks may represent an efficient method for controlling Didymella crown rot and Fusarium wilt. [source] A fractional adaptation law for sliding mode controlINTERNATIONAL JOURNAL OF ADAPTIVE CONTROL AND SIGNAL PROCESSING, Issue 10 2008Mehmet Önder Efe Abstract This paper presents a novel parameter tuning law that forces the emergence of a sliding motion in the behavior of a multi-input multi-output nonlinear dynamic system. Adaptive linear elements are used as controllers. Standard approach to parameter adjustment employs integer order derivative or integration operators. In this paper, the use of fractional differentiation or integration operators for the performance improvement of adaptive sliding mode control systems is presented. Hitting in finite time is proved and the associated conditions with numerical justifications are given. The proposed technique has been assessed through a set of simulations considering the dynamic model of a two degrees of freedom direct drive robot. It is seen that the control system with the proposed adaptation scheme provides (i) better tracking performance, (ii) suppression of undesired drifts in parameter evolution, (iii) a very high degree of robustness and improved insensitivity to disturbances and (iv) removal of the controller initialization problem. Copyright © 2008 John Wiley & Sons, Ltd. [source] THE EFFECT OF AIR-DRYING, FREEZE-DRYING AND STORAGE ON THE QUALITY AND ANTIOXIDANT ACTIVITY OF SOME SELECTED BERRIESJOURNAL OF FOOD PROCESSING AND PRESERVATION, Issue 1 2009MAGDALENA MICHALCZYK ABSTRACT The aim of this study was to analyze the effects of air-drying and freeze-drying and subsequent storage of dried products on the content of polyphenols, anthocyanins and the antioxidant properties of selected berry fruits. The material was raspberry (Rubus ideaus L.), strawberry (Fragaria ananassa Duch) and bilberry (Vaccinum myrtillus). Despite exposure to atmospheric oxygen, the stored freeze-dried fruit retained the properties of the raw material better than the air-dried product. In the case of the latter, there were considerable differences in the retention of total polyphenolic and anthocyanin content as well as antioxidant properties in the three fruit species examined. In particular, bilberry maintained a high polyphenol and anthocyanin content and high antioxidant potential despite the greatest losses of these compounds. PRACTICAL APPLICATIONS Consumer demand for food with health-promoting qualities is increasing. The food industry has intensified its efforts to provide high quality, semi-processed products that fulfil this requirement. The results presented in this work indicate that even after long-term storage and despite exposure to atmospheric oxygen, freeze-dried berries retain the antioxidant properties of the raw material to a very high degree. Therefore, lyophilisates can satisfy this particular need. Air-dried berries are much less stable during long-term storage. The dynamics of the changes occurring during the storage of both kinds of product are presented in detail. [source] Analysis of the VP6 gene of human and porcine group A rotavirus strains with unusual subgroup specificitiesJOURNAL OF MEDICAL VIROLOGY, Issue 1 2009Aksara Thongprachum Abstract Full-length VP6 amino acid sequences of human and porcine rotaviruses with subgroup (SG) (I,+,II) and SG non-(I,+,II) were analyzed in comparison with those of SG I and SG II. In human rotaviruses, the strains in the same SG shared a very high degree of amino acid identity, ranging from 97.4% to 99.4% for SG I, 95.9% to 100% for SG II, and 99.4% to100% for SG non-(I,+,II), while viruses in different SGs shared somewhat lower sequence identity at 90.4,93.1%. Conserved amino acids that distinguished the strains of SG I from SG II were observed at 21 positions. The viruses with SG non-(I,+,II) shared sequence identity with SG II as high as 97.2,99.7%, suggesting that they belonged to genogroup II. Similarly, porcine rotaviruses in the same SG shared 96.4,99.7% for SG I, 98.2,100% for SG II, 97.4,100% for SG (I,+,II), and 96.2,99.7% for SG non-(I,+,II), while strains in different SGs shared sequence identity ranging from 91.9% to 94.4%. Interestingly, the strains with SG (I,+,II) and SG non-(I,+,II) shared a high degree of sequence identity with SG I, at 96.4,100% and 94.7,99.7% respectively, suggesting that they are related to porcine SG I strains. The conserved amino acids which distinguished SG I from SG II were observed at 13 positions. The strains with SG I, SG (I,+,II), and SG non-(I,+,II) showed identical amino acid residues at these positions. Phylogenetic analysis strongly supported the findings of the sequence analysis. J. Med. Virol. 81:183,191, 2009. © 2008 Wiley-Liss, Inc. [source] Characterization of microsatellite markers in Fagus sylvatica L. and Fagus orientalis LipskyMOLECULAR ECOLOGY RESOURCES, Issue 1 2003R. Pastorelli Abstract Using an enrichment procedure, we cloned microsatellite repeats from European beech (Fagus sylvatica L.) and developed primers for the amplification of microsatellite markers. Six polymorphic loci were characterized which produced 3,21 alleles in 70 individuals from one Italian population, with an observed heterozygosity between 0.58 and 0.85. All six loci amplified fragments which were polymorphic in the closely related species, Fagus orientalis, also. Owing to their very high degree of variation, these markers should be very useful in gene flow studies of these species. [source] Decentralization in Kerala: Panchayat government discretion and accountability,PUBLIC ADMINISTRATION & DEVELOPMENT, Issue 4 2009Varsha Venugopal Kerala is regarded as one of the most decentralized states in India. Through a ,big bang' approach, Kerala implemented a significant fiscal decentralization program and then built the capacity of its local governments. We employ a diagnostic framework to analyze its local government discretion and accountability in political, administrative and fiscal domains. We find that Kerala's local governments have a very high degree of discretionary power accompanied by a high degree of accountability towards citizens. But the areas of administrative accountability and financial management need to be strengthened. Also there may have been excessive focus and investment on social accountability mechanisms at the cost of local government discretion and formal public sector accountability mechanisms. Copyright © 2009 John Wiley & Sons, Ltd. [source] Fenton and photo-Fenton treatment of distillery effluent and optimization of treatment conditions with response surface methodologyASIA-PACIFIC JOURNAL OF CHEMICAL ENGINEERING, Issue 3 2010Mojtaba Hadavifar Abstract Two chemical processes, Fenton and photo-Fenton, were tested separately for the treatment of vinasse, which was generated from an alcohol distillery process. In order to evaluate the processes effectiveness, four independent variables viz. SCOD concentration, initial pH, H2O2 and FeSO4 dosage were applied. Experiments were conducted based on a central composite design (CCD) and analyzed using response surface methodology (RSM). UV radiation for 80 min was applied in each experiment during the photo-Fenton process. Two modified quadratic equations were used for data fitting. The most significant model terms in the processes were found to be the initial chemical oxygen demand (COD) concentration and the initial pH. A higher removal efficiency was achieved in the photo-Fenton process compared to Fenton alone. The efficiency varied from 18 to 97% for the photo-Fenton process, while it was in the range of 5,47% for Fenton process. The R2 value of the models (R2 > 0.97) shows a very high degree of correlation between the parameters. Copyright © 2009 Curtin University of Technology and John Wiley & Sons, Ltd. [source] Pulsations and planets: The asteroseismology-extrasolar-planet connectionASTRONOMISCHE NACHRICHTEN, Issue 5 2010S. Schuh Abstract The disciplines of asteroseismology and extrasolar planet science overlap methodically in the branch of high-precision photometric time series observations. Light curves are, amongst others, useful to measure intrinsic stellar variability due to oscillations, as well as to discover and characterize those extrasolar planets that transit in front of their host stars, periodically causing shallow dips in the observed brightness. Both fields ultimately derive fundamental parameters of stellar and planetary objects, allowing to study for example the physics of various classes of pulsating stars, or the variety of planetary systems, in the overall context of stellar and planetary system formation and evolution. Both methods typically also require extensive spectroscopic follow-up to fully explore the dynamic characteristics of the processes under investigation. In particularly interesting cases, a combination of observed pulsations and signatures of a planet allows to characterize a system's components to a very high degree of completeness by combining complementary information. The planning of the relevant space missions has consequently converged with respect to science cases, where at the outset there was primarily a coincidence in instrumentation and techniques. Whether space- or ground-based, a specific type of stellar pulsations can themselves be used in an innovative way to search for extrasolar planets. Results from this additional method at the interface of stellar pulsation studies and exoplanet hunts in a beyond-mainstream area are presented (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] An overview of recent findings of the Stanley Foundation Bipolar Network (Part I)BIPOLAR DISORDERS, Issue 5 2003Robert M Post Aim and Methods: Selected recent findings of the Stanley Foundation Bipolar Network are briefly reviewed and their clinical implications discussed. Results: Daily prospective ratings on the NIMH-LCM indicate a high degree of residual depressive morbidity (three times that of hypomania or mania) despite active psychopharmacological treatment with a variety of modalities including mood stabilizers, antidepressants, and benzodiazepines, as well as antipsychotics as necessary. The rates of switching into brief to full hypomania or mania during the use of antidepressants is described, and new data suggesting the potential utility of continuing antidepressants in the small group of patients showing an initial acute and persistent response is noted. Bipolar patients with a history of major environmental adversities in childhood have a more severe course of illness and an increased incidence of suicide attempts compared with those without. Preliminary open data suggest useful antidepressant effects of the atypical antipsychotic quetiapine, while a double-blind randomized controlled study failed to show efficacy of omega-3 fatty acids (6 g of eicosapentaenoic acid compared with placebo for 4 months) in the treatment of either acute depression or rapid cycling. The high prevalence of overweight and increased incidence of antithyroid antibodies in patients with bipolar illness is highlighted. Conclusions: Together, these findings suggest a very high degree of comorbidity and treatment resistance in outpatients with bipolar illness treated in academic settings and the need to develop not only new treatment approaches, but also much earlier illness recognition, diagnosis, and intervention in an attempt to reverse or prevent this illness burden. [source] Effects of Isomerization on the Measured Thermochemical Properties of Deprotonated Glycine/Protic-Solvent ClustersCHEMPHYSCHEM, Issue 18 2008Robert J. Nieckarz Dr. Abstract The thermochemical properties associated with the formation of an isomeric distribution of ROH,,,NH2CH2COO, clusters (R=H, CH3, C2H5) are measured by using high-pressure mass spectrometry. A comparison of the measured properties with calculated values provides new insights into the thermochemical effects arising from the isomeric nature of this clustering system. When the distribution of isomers is correctly accounted for, the measured values of ,H°, ,S°, and ,G°298 consistently agree, to a very high degree of accuracy, with those predicted by MP2(full)/6-311++G(d,p)//B3LYP/6-311++G(d,p) calculations. [source] | |||||||||||||