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Different Years (different + year)
Selected AbstractsCorrelation between Moisture and Water Activity of Honeys Harvested in Different YearsJOURNAL OF FOOD SCIENCE, Issue 5 2004M.M. Cavia ABSTRACT: For the 1st time, a relationship has been investigated between moisture percentage (M) and water activity (aW) in honeys from 2 different harvesting years and 2 different climatic areas. Moisture was determined by measuring refractive index at 20°C, according to official methods. At the same time, aW of the same samples was assessed at exactly 20°C. Influence on the relationship of the crop's year, aging, and induced fine granulation was evaluated. The results show that, independent of all factors studied, an excellent and statistically significant linear correlation between both parameters [aW = 0.3114 + (0.0170 × M)] was found in all samples with a regression coefficient of 0.8809. The measurement of aW of honey is interesting but time-consuming. This study concludes that this parameter can be easily calculated from the moisture percentage, thus avoiding the use of expensive and slow equipment for aW measurement. [source] Temporal variability of phytoplankton in a salt wedge estuary, the Swan,Canning Estuary, Western AustraliaHYDROLOGICAL PROCESSES, Issue 13 2001Peter A. Thompson Abstract The temporal cycles of variation in salinity, temperature and river flow in the Swan,Canning Estuary plus rainfall in the vicinity are examined. A ,normal' pattern is defined for rainfall and river flow based on long-term median monthly values from available historical data. Long-term monthly median rainfall and median monthly river flow were highly correlated. Deviations from the ,normal' patterns of rainfall and river flow are documented. Three years of detailed data on the temporal distribution of the algal biomass and phytoplankton community composition from the Swan,Canning Estuary are presented and discussed. Significant interannual variability in the phytoplankton biomass was observed with 1996 having a significantly lower median chlorophyll a concentration than 1995 or 1997. Different years also had pronounced differences in the timing, persistence and occurrence of algal blooms. Links with, and between, rainfall, river flow, nutrient concentrations and phytoplankton biomass are made by careful examination of the temporal patterns. Deviations from the proposed ,normal' temporal pattern of physical and chemical environmental factors relevant to the growth of phytoplankton biomass are assessed. Deviations from ,normal' rainfall and river flow, depending upon their timing and intensity, appear to be associated with occurrence of algal blooms. For example, the lack of a dinoflagellate bloom in December 1996 or January 1997 appears to be associated with a wetter than normal spring. Based upon the observed data, published reports and basic principles of algal ecology a set of predicted responses to variation in the major environmental variables (rainfall and river flow) are tabulated. The tabulated predictions are proposed as a useful tool for resource managers. Copyright © 2001 John Wiley & Sons, Ltd. [source] Epidemiology of invasive and other pneumococcal disease in children in England and Wales 1996,1998ACTA PAEDIATRICA, Issue 2000E Miller The results of enhanced national surveillance of pneumococcal disease in children <15y of age in England and Wales are reported for the period 1996,1998. Of the 1985 cases of laboratory-confirmed invasive disease (annual incidence 6.6 per 100000 overall and 39.7 per 100000 in infants <1 y of age), 485 (24%) were meningitis (annual incidence of 1.6 per 100000 overall and 15.7 per 100000 in infants <1 y of age). Fifty-nine deaths in children with invasive disease were identified-3% of the total reports. Thirty-one different serogroups/types were identified, with organisms in the 7-valent conjugate vaccine responsible for 69% of the infections in children <5 y of age; this rose to 77% and 82%, respectively, for the 9-and 11-valent vaccines. Resistance to penicillin varied from 2.3% to 6.2% in different years, but erythromycin resistance remained constant at 17%. The vast majority of resistant isolates were in vaccine serotype/groups. Computerized hospital admission records for all children <15 y of age with a discharge diagnosis code indicating probable pneumococcal disease were also analysed for 1997. The annual incidence for cases with a code specifically mentioning S. pneumoniae was 9.9 per 100000 compared with 71.2 per 100000 for lobar pneumonia; the mean duration of stay for both was < 1 wk. The incidence of admission for pneumococcal meningitis (1.9 overall and 19.6 for infants < 1 y of age) was similar to that derived from laboratory reports and resulted in an average duration of stay of 2 wk. Conclusion: This surveillance has confirmed the substantial burden of morbidity attributable to pneumococcal disease in British children and the potential public health benefits that could be achieved by the use of pneumococcal conjugate vaccines. [source] Learners' Descriptions of German Pronunciation, Vocabulary, and Grammar: A Folk Linguistic AccountDIE UNTERRICHTSPRAXIS/TEACHING GERMAN, Issue 1 2009Monika Chavez Following a folk linguistic approach, this investigation of first-, second- and fourth-year learners' accounts of German found that (1) few had held pre-conceived notions about German prior to language study; (2) most pre-conceived notions concerned German pronunciation; (3) pre-conceived notions about vocabulary were most likely to influence the decision to study German; and (4) among current perceptions of German, learners (a) believe German to be more "systematic" than English; (b) are virtually exclusively concerned with rules of "accuracy" (not appropriateness); (c) tend to judge the "merits" of German rules in comparison with English but also the Romance languages; (d) consider grammar more different between English and German than vocabulary and pronunciation; and (e) register no observable differences across different years of study or between German and non-German majors. [source] Recent channel adjustments in alluvial rivers of Tuscany, central ItalyEARTH SURFACE PROCESSES AND LANDFORMS, Issue 6 2003Massimo RinaldiArticle first published online: 19 JUN 200 Abstract Drastic channel adjustments have affected the main alluvial rivers of Tuscany (central Italy) during the 20th century. Bed-level adjustments were identified both by comparing available topographic longitudinal profiles of different years and through field observations. Changes in channel width were investigated by comparing available aerial photographs (1954 and 1993,98). Bed incision represents the dominant type of vertical adjustment, and is generalized along all the fluvial systems investigated. The Arno River system is the most affected by bed-level lowering (up to 9 m), whereas lower incision (generally less than 2 m) is observed along the rivers of the southern part of the region. Human disturbances appear to be the dominant factors of adjustments: the main phase of vertical change occurred during the period 1945,80, in concomitance with the phase of maximum sediment mining activity at the regional scale. The second dominant type of adjustment that involved most of the rivers in the region consists of a narrowing of the active channel. Based on measurements of channel width conducted on aerial photographs, 38% of the reaches analysed experienced a narrowing greater than 50% of the initial channel width. The largest values of channel narrowing were observed along initially braided or sinuous with alternate bars morphologies in the southern portion of the region. A regional scheme of channel adjustments is derived, based on initial channel morphology and on the amounts of incision and narrowing. Different styles of channel adjustments are described. Rivers that were originally sinuous with alternate bars to braided generally became adjusted by a moderate incision and a moderate to intense narrowing; in contrast, sinuous-meandering channels mainly adjusted vertically, with a minor amount of narrowing. Copyright © 2003 John Wiley & Sons, Ltd. [source] Density-dependent growth of young-of-the-year Atlantic salmon (Salmo salar) revisitedECOLOGY OF FRESHWATER FISH, Issue 1 2010I. Imre Imre I, Grant JWA, Cunjak RA. Density-dependent growth of young-of-the-year Atlantic salmon (Salmo salar) revisited. Ecology of Freshwater Fish 2010: 19: 1,6. © 2009 John Wiley & Sons A/S Abstract,,, The length of individual young-of-the-year (YOY) Atlantic salmon (Salmo salar) in Catamaran Brook decreases with increasing population density following a negative power curve. Because most of this decrease in growth rate occurs at low densities (<1 fish·m,2), (Imre et al. 2005; Journal of Animal Ecology, 74: 508,516) suggested that exploitation competition for drifting prey rather than space limitation might be responsible for this pattern. Recently, (Ward et al. 2007; Journal of Animal Ecology, 76: 135,138) showed that the negative power curve of growth rate versus density can be caused by other mechanisms and suggested that Imre et al.'s evidence for density-dependent growth would have been stronger if we had analysed final size versus initial density rather than final density. We examined (i) whether the negative power curve of size versus density was also apparent in an analysis of final size versus initial density and tested two predictions that emerge from Ward et al.'s model, (ii) the variance in body size increases with population density, and (iii) the maximum fish size at a site is density-independent. The final size of YOY salmon decreased with increasing initial density following a negative power curve. Our data did not provide strong support for the above predictions emerging from Ward et al.'s model. Our analyses of different years, sites and seasons were consistent with the hypothesis of density-dependent growth of YOY salmon. [source] Genetic variability in environmental isolates of Legionella pneumophila from Comunidad Valenciana (Spain)ENVIRONMENTAL MICROBIOLOGY, Issue 6 2006Mireia Coscollá Summary Legionella pneumophila is associated to recurrent outbreaks in several Comunidad Valenciana (Spain) localities, especially in Alcoi, where social and climatic conditions seem to provide an excellent environment for bacterial growth. We have analysed the nucleotide sequences of three loci from 25 environmental isolates from Alcoi and nearby locations sampled over 3 years. The analysis of these isolates has revealed a substantial level of genetic variation, with consistent patterns of variability across loci, and comparable to that found in a large, European-wide sampling of clinical isolates. Among the tree loci studied, fliC showed the highest level of nucleotide diversity. The analysis of isolates sampled in different years revealed a clear differentiation, with samples from 2001 being significantly distinct from those obtained in 2002 and 2003. Furthermore, although linkage disequilibrium measures indicate a clonal nature for population structure in this sample, the presence of some recombination events cannot be ruled out. [source] The influence of environment and spawning distribution on the survival of anchovy (Engraulis encrasicolus) larvae in the Bay of Biscay (NE Atlantic) investigated by biophysical simulationsFISHERIES OCEANOGRAPHY, Issue 6 2007GWENHAEL ALLAIN Abstract A growth and survival model of the early life stages was run along virtual drift trajectories tracked in a hydrodynamic model to simulate the annual recruitment process of anchovy (Engraulis encrasicolus) in the Bay of Biscay (NE Atlantic). These biophysical simulations concerning three different years were analysed in order to investigate the influence of environment and spawning dynamics on the survival of larvae and juveniles. The location of space,time survival windows suggested major environmental mechanisms involved in simulated recruitment variability at the different scales , retention of larvae and juveniles in favourable habitats over the shelf margins and turbulence effects. These small-scale and meso-scale mechanisms were related to the variations in wind direction and intensity during spring and summer. Survival was also variable according to the origin of the drift trajectories, that is spawning distribution in space and time. The observed spawning distribution (according to field surveys) was compared with the spawning distribution that would maximize survival (according to the biophysical model) on a seasonal scale, which revealed factors not considered in the biophysical model (e.g. spawning behaviour of the different age classes). The variation of simulated survival according to spawning distribution was examined on a multi-annual scale and showed a coherent pattern with past and present stock structures. The interaction processes between the population (influence on spawning) and its environment (influence on survival) and its implications on recruitment and stock dynamics are discussed. [source] Temporal coherence of two alpine lake basins of the Colorado Front Range, U.S.A.FRESHWATER BIOLOGY, Issue 3 2000J. I. L. L. S. Baron 1. Knowledge of synchrony in trends is important to determining regional responses of lakes to disturbances such as atmospheric deposition and climate change. We explored the temporal coherence of physical and chemical characteristics of two series of mostly alpine lakes in nearby basins of the Colorado Rocky Mountains. Using year-to-year variation over a 10-year period, we asked whether lakes more similar in exposure to the atmosphere be-haved more similarly than those with greater influence of catchment or in-lake processes. 2. The Green Lakes Valley and Loch Vale Watershed are steeply incised basins with strong altitudinal gradients. There are glaciers at the heads of each catchment. The eight lakes studied are small, shallow and typically ice-covered for more than half the year. Snowmelt is the dominant hydrological event each year, flushing about 70% of the annual discharge from each lake between April and mid-July. The lakes do not thermally stratify during the period of open water. Data from these lakes included surface water temper-ature, sulphate, nitrate, calcium, silica, bicarbonate alkalinity and conductivity. 3. Coherence was estimated by Pearson's correlation coefficient between lake pairs for each of the different variables. Despite close geographical proximity, there was not a strong direct signal from climatic or atmospheric conditions across all lakes in the study. Individual lake characteristics overwhelmed regional responses. Temporal coherence was higher for lakes within each basin than between basins and was highest for nearest neighbours. 4. Among the Green Lakes, conductivity, alkalinity and temperature were temporally coherent, suggesting that these lakes were sensitive to climate fluctuations. Water tem-perature is indicative of air temperature, and conductivity and alkalinity concentrations are indicative of dilution from the amount of precipitation flushed through by snowmelt. 5. In Loch Vale, calcium, conductivity, nitrate, sulphate and alkalinity were temporally coherent, while silica and temperature were not. This suggests that external influences are attenuated by internal catchment and lake processes in Loch Vale lakes. Calcium and sulphate are primarily weathering products, but sulphate derives both from deposition and from mineral weathering. Different proportions of snowmelt versus groundwater in different years could influence summer lake concentrations. Nitrate is elevated in lake waters from atmospheric deposition, but the internal dynamics of nitrate and silica may be controlled by lake food webs. Temperature is attenuated by inconsistently different climates across altitude and glacial meltwaters. 6. It appears that, while the lakes in the two basins are topographically close, geologically and morphologically similar, and often connected by streams, only some attributes are temporally coherent. Catchment and in-lake processes influenced temporal patterns, especially for temperature, alkalinity and silica. Montane lakes with high altitudinal gradients may be particularly prone to local controls compared to systems where coherence is more obvious. [source] The impact of groundwater,surface water interactions on the water balance of a mesoscale lowland river catchment in northeastern GermanyHYDROLOGICAL PROCESSES, Issue 2 2007Stefan Krause Abstract The glacially formed northeastern German lowlands are characterized by extensive floodplains, often interrupted by relatively steep moraine hills. The hydrological cycle of this area is governed by the tight interaction of surface water dynamics and the corresponding directly connected shallow groundwater aquifer. Runoff generation processes, as well as the extent and spatial distribution of the interaction between surface water and groundwater, are controlled by floodplain topography and by surface water dynamics. A modelling approach based on extensive experimental analyses is presented that describes the specific water balance of lowland areas, including the interactions of groundwater and surface water, as well as reflecting the important role of time-variable shallow groundwater stages for runoff generation in floodplains. In the first part, experimental investigations of floodplain hydrological characteristics lead to a qualitative understanding of the water balance processes and to the development of a conceptual model of the water balance and groundwater dynamics of the study area. Thereby model requirements which allow for an adequate simulation of the floodplain hydrology, considering also interactions between groundwater and surface water have been characterized. Based on these analyses, the Integrated Modelling of Water Balance and Nutrient Dynamics (IWAN) approach has been developed. This consists of coupling the surface runoff generation and soil water routines of the deterministic, spatially distributed hydrological model WASIM-ETH-I with the three-dimensional finite-difference-based numerical groundwater model MODFLOW and Processing MODFLOW. The model was applied successfully to a mesoscale subcatchment of the Havel River in northeast Germany. It was calibrated for two small catchments (1·4 and 25 km2), where the importance of the interaction processes between groundwater and surface waters and the sensitivity of several controlling parameters could be quantified. Validation results are satisfying for different years for the entire 198 km2 catchment. The model approach was further successfully tested for specific events. The experimental area is a typical example of a floodplain-dominated landscape. It was demonstrated that the lateral flow processes and the interactions between groundwater and surface water have a major importance for the water balance and periodically superimposed on the vertical runoff generation. Copyright © 2006 John Wiley & Sons, Ltd. [source] Multiple-brooding in birds of prey: South African Black Sparrowhawks Accipiter melanoleucus extend the boundariesIBIS, Issue 1 2005ODETTE CURTIS Multiple-brooding (raising more than one brood of young in quick succession) occurs infrequently in raptors and is generally restricted to either smaller species with shorter nesting periods, co-operative breeders or species capable of capitalizing on conditions of prolonged food abundance whenever they occur. This paper presents the first recorded cases of multiple-brooding in the Black Sparrowhawk Accipiter melanoleucus from two distinct locales in South Africa. In the Western Cape (Cape Peninsula), four attempts to multiple-brood were recorded in four different years, involving three distinct pairs of birds, and in KwaZulu,Natal (Eshowe), three distinct pairs of Sparrowhawks successfully multiple-brooded on several occasions over a 5-year study period. These results establish the Black Sparrowhawk as one of only two relatively large, monogamous raptor species, and the only specialist bird-eating raptor, in which multiple-brooding has been recorded with any frequency. The species' capacity to thrive in human-modified environments (i.e. alien plantations) and particularly to exploit associated foraging opportunities (e.g. high densities of doves and pigeons in suburban areas) may, at least partly, account for the instances of multiple-brooding reported here. We suggest that biologists be more vigilant for cases of multiple-brooding in raptors, as it is possible that this trait is more common than originally thought and has previously been overlooked. [source] Calculating census efficiency for river birds: a case study with the White-throated Dipper Cinclus cinclus in the PyrénéesIBIS, Issue 1 2003Frank D'Amico Using the binomial law we modelled field data to estimate the probability (p,) of detecting pairs of breeding White-throated Dippers, and the population size (N,± confidence limits). The model was divided into two parts according to whether the actual size of the population under study was known or not; in the latter case the truncated binomial model was used. Dipper abundance data were collected from three 4-km-long river tracts in the Pyrénées (France) during the breeding seasons of different years. Goodness-of-fit tests indicated that the binomial model fitted the data well. For a given visit during the survey, the estimated probability of detecting any pair of Dippers if they were present was always high (0.63,0.94) and constant from year to year but not between sites. Estimations (N,) of the size of the population provided by the binomial model were very close to that derived from mapping techniques. This study provides the first ever quantification of the number of visits required to detect birds on linear territories: three visits were necessary to detect the whole breeding population. [source] Phenotypic characteristics of novel swine-origin influenza A/California/07/2009 (H1N1) virusINFLUENZA AND OTHER RESPIRATORY VIRUSES, Issue 1 2010Irina Kiseleva Background, The 2009 novel A(H1N1) virus appears to be of swine origin. This strain causing the current outbreaks is a new virus that has not been seen previously either in humans or animals. We have previously reported that viruses causing pandemics or large outbreaks were able to grow at a temperature above the normal physiological range (temperature resistance, non-ts phenotype), were found to be inhibitor resistant and restricted in replication at suboptimal temperature (sensitivity to grow at low temperature, non-ca phenotype). In this study, we performed phenotypic analysis of novel A(H1N1) virus to evaluate its pandemic potential and its suitability for use in developing a live attenuated influenza vaccine. Objectives, The goal of this study is to identify phenotypic properties of novel A(H1N1) influenza virus. Methods, A/California/07/2009 (H1N1) swine-origin influenza virus was studied in comparison with some influenza A viruses isolated in different years with respect to their ability to grow at non-permissive temperatures. We also analyzed its sensitivity to gamma-inhibitors of animal sera and its ability to agglutinate chicken, human and guinea pig erythrocytes. Results, Swine-origin A/California/07/2009 (H1N1) virus was found to be non-ts and inhibitor resistant and was not able to grow at 25°C (non-ca). We did not find any difference in the ability of the hemagglutinin of A/California/07/2009 (H1N1) virus to bind to erythrocytes of different origin. Conclusion, The novel swine-origin A(H1N1) virus displays a phenotype typical of the past pandemic and epidemic viruses. This finding suggests that this virus might be a good wild type parental prototype for live vaccine for potential use for controlling pandemic influenza. [source] Conservation strategy maps: a tool to facilitate biodiversity action planning illustrated using the heath fritillary butterflyJOURNAL OF APPLIED ECOLOGY, Issue 2 2003G. J. Holloway Summary 1.,The UK Biodiversity Action Plan (UKBAP) identifies invertebrate species in danger of national extinction. For many of these species, targets for recovery specify the number of populations that should exist by a specific future date but offer no procedure to plan strategically to achieve the target for any species. 2.,Here we describe techniques based upon geographic information systems (GIS) that produce conservation strategy maps (CSM) to assist with achieving recovery targets based on all available and relevant information. 3.,The heath fritillary Mellicta athalia is a UKBAP species used here to illustrate the use of CSM. A phase 1 habitat survey was used to identify habitat polygons across the county of Kent, UK. These were systematically filtered using relevant habitat, botanical and autecological data to identify seven types of polygon, including those with extant colonies or in the vicinity of extant colonies, areas managed for conservation but without colonies, and polygons that had the appropriate habitat structure and may therefore be suitable for reintroduction. 4.,Five clusters of polygons of interest were found across the study area. The CSM of two of them are illustrated here: the Blean Wood complex, which contains the existing colonies of heath fritillary in Kent, and the Orlestone Forest complex, which offers opportunities for reintroduction. 5.,Synthesis and applications. Although the CSM concept is illustrated here for the UK, we suggest that CSM could be part of species conservation programmes throughout the world. CSM are dynamic and should be stored in electronic format, preferably on the world-wide web, so that they can be easily viewed and updated. CSM can be used to illustrate opportunities and to develop strategies with scientists and non-scientists, enabling the engagement of all communities in a conservation programme. CSM for different years can be presented to illustrate the progress of a plan or to provide continuous feedback on how a field scenario develops. [source] Microsatellites assessment of Chinese sturgeon (Acipenser sinensis Gray) genetic variabilityJOURNAL OF APPLIED ICHTHYOLOGY, Issue 1 2005N. Zhao Summary Four microsatellites were used to examine the genetic variability of the spawning stocks of Chinese sturgeon, Acipenser sinensis, from the Yangtze River sampled over a 3-year period (1999,2001). Within 60 individuals, a total of 28 alleles were detected over four polymorphic microsatellite loci. The number of alleles per locus ranged from 4 to 15, with an average allele number of 7. The number of genotypes per locus ranged from 6 to 41. The genetic diversity of four microsatellite loci varied from 0.34 to 0.67, with an average value of 0.54. For the four microsatellite loci, the deviation from the Hardy,Weinberg equilibrium was mainly due to null alleles. The mean number of alleles per locus and the mean heterozygosity were lower than the average values known for anadromous fishes. Fish were clustered according to their microsatellite characteristics using an unsupervised ,Artificial Neural Networks' method entitled ,Self-organizing Map'. The results revealed no significant genetic differentiation considering genetic distance among samples collected during different years. Lack of heterogeneity among different annual groups of spawning stocks was explained by the complex age structure (from 8 to 27 years for males and 12 to 35 years for females) of Chinese sturgeon, leading to formulate an hypothesis about the maintenance of genetic diversity and stability in long-lived animals. [source] Comparison of Salmonella enterica serotype Infantis isolates from a veterinary teaching hospitalJOURNAL OF APPLIED MICROBIOLOGY, Issue 6 2007M. Dunowska Abstract Aims:, To compare Salmonella enterica serotype Infantis isolates obtained from patients or the environment of a veterinary teaching hospital over a period of 9 years following a nosocomial outbreak to determine whether isolates were epidemiologically related or represented unrelated introductions into the hospital environment. Methods and Results:, Fifty-six S. Infantis isolates were compared based on their phenotypic (antimicrobial drug [AMD] susceptibility pattern) and genotypic (pulsed-field gel electrophoresis [PFGE] pattern and presence of integrons) characteristics. Epidemiologically unrelated S. Infantis isolates clustered separately from all but two of the hospital isolates, and several isolates from different years and various sources were indistinguishable from each other in cluster analysis of two-enzyme PFGE results. A high percentage of isolates (80·3%) were resistant to at least one AMD, with 67·8% showing resistance to >5 AMD. The majority (74·1%) of isolates tested contained type 1 integrons. Conclusion:, Results strongly suggest that there was nosocomial transmission of S. Infantis during the initial outbreak, and that contamination arising from this outbreak persisted across years despite rigorous hygiene and biosecurity precautions and may have led to subsequent nosocomial infections. Significance and Impact of the Study:, Evidence of persistence and transmission of Salmonella clones across years, even in the face of rigorous preventive measures, has important implications for other facilities that have experienced outbreaks of Salmonella infections. [source] Year-to-year variation in plant competition in a mountain grasslandJOURNAL OF ECOLOGY, Issue 1 2003Herben Summary 1We used a series of removal experiments to examine how species response to competition and climatic differences varied in three different years. We tested the interaction between removal of the dominant grass species, Festuca rubra, and year-to-year environmental variation in a mown mountain grassland. 2In each year, we quantified shoot frequency and above-ground biomass of all remaining plant species. Above-ground responses were tested both by analysis of covariance and by redundancy analysis with randomization tests of changes in total species composition. 3Analysis of above-ground biomass data showed that other species compensated for the removal of F. rubra biomass within 2 years and that the response in total biomass of the community did not differ among years in which the experiment was started. 4Multivariate tests showed that species composition changed as a result of the removal; grass biomass and frequency increased more than that of dicotyledons. However, response of species composition to removal of F. rubra was significantly different between onset years. Specific conditions in individual years thus affect the competitive ability of individual species in a non-additive way. 5Our results indicate that the year-to-year variation at the site has the potential to affect species coexistence and richness. As a consequence, year-to-year variation of climatic parameters may be an important driving factor in community dynamics and should be taken into account in studies of ecosystem response to climate. [source] Between-year variation of MHC allele frequencies in great reed warblers: selection or drift?JOURNAL OF EVOLUTIONARY BIOLOGY, Issue 3 2004H. Westerdahl Abstract The major histocompatibility complex (MHC) genes are extremely polymorphic and this variation is assumed to be maintained by balancing selection. Cyclic interactions between pathogens and their hosts could generate such selection, and specific MHC alleles or heterozygosity at certain MHC loci have been shown to confer resistance against particular pathogens. Here we compare the temporal variation in allele frequencies of 23 MHC class I alleles with that of 23 neutral microsatellite markers in adult great reed warblers (a passerine bird) in nine successive cohorts. Overall, the MHC alleles showed a significantly higher variation in allele frequencies between cohorts than the microsatellite alleles, using a multi-variate genetic analysis (amova). The frequency of two specific MHC alleles, A3e (P = 0.046) and B4b (P = 0.0018), varied more between cohorts than expected from random, whereas none of the microsatellite alleles showed fluctuations exceeding the expectation from stochastic variation. These results imply that the variation in MHC allele frequencies between cohorts is not a result of demographic events, but rather an effect of selection favouring different MHC alleles in different years. [source] CHARACTERISTICS OF FERMENTED NATTO PRODUCTS AS AFFECTED BY SOYBEAN CULTIVARSJOURNAL OF FOOD PROCESSING AND PRESERVATION, Issue 4 2004QUN WEI ABSTRACT The characteristics of four soybean cultivars, grown in the Northern plain region of the U.S.A. and harvested in different years were investigated. These soybeans were fermented into natto products. The characteristics of the intermediate and finished products were analyzed. Correlation coefficients among certain physical, chemical, sensory characteristics of raw soybeans, intermediate products and finished products were significant (P < 0.05). The ammonia content significantly correlated with firmness of the natto products made from these cultivars (r = 0.65). Minnatto and MN 91-468 cultivars were similar to the Danatto cultivar in objective measurements and sensory properties. Compared with the other cultivars, Natto King had a higher solid matter content (1.92%) in the soaking water, a higher broken bean ratio (22.71%) after steaming and the hardest texture of the finished natto products. The effect of harvest year of Danatto cultivars and the quality attributes of the finished natto products varied with Bacillus natto strains. [source] Design, validation, and use of an evaluation instrument for monitoring systemic reformJOURNAL OF RESEARCH IN SCIENCE TEACHING, Issue 6 2001Kathryn Scantlebury Over the past decade, state and national policymakers have promoted systemic reform as a way to achieve high-quality science education for all students. However, few instruments are available to measure changes in key dimensions relevant to systemic reform such as teaching practices, student attitudes, or home and peer support. Furthermore, Rasch methods of analysis are needed to permit valid comparison of different cohorts of students during different years of a reform effort. This article describes the design, development, validation, and use of an instrument that measures student attitudes and several environment dimensions (standards-based teaching, home support, and peer support) using a three-step process that incorporated expert opinion, factor analysis, and item response theory. The instrument was validated with over 8,000 science and mathematics students, taught by more than 1,000 teachers in over 200 schools as part of a comprehensive assessment of the effectiveness of Ohio's systemic reform initiative. When the new four-factor, 20-item questionnaire was used to explore the relative influence of the class, home, and peer environment on student achievement and attitudes, findings were remarkably consistent across 3 years and different units and methods of analysis. All three environments accounted for unique variance in student attitudes, but only the environment of the class accounted for unique variance in student achievement. However, the class environment (standards-based teaching practices) was the strongest independent predictor of both achievement and attitude, and appreciable amounts of the total variance in attitudes were common to the three environments. © 2001 John Wiley & Sons, Inc. J Res Sci Teach 38: 646,662, 2001 [source] Exploring spatiotemporal patterns in early stages of primary succession on former lignite mining sitesJOURNAL OF VEGETATION SCIENCE, Issue 2 2008Birgit Felinks Abstract Questions: 1. Does random colonization predominate in early stages of primary succession? 2. Do pioneer species facilitate the establishment of later arriving species? 3. Does an initially random distribution change to an aggregated pattern with ongoing succession? Location: Lignite mining region of Lower Lusatia, eastern Germany. Methods: Individual plants were mapped along a 2 m × 28 m transect during three successive years and classified into two groups (1) the pioneer Corynephorus canescens and (2),all other species'. Using the pair-correlation function, univariate point pattern analysis was carried out by applying a heterogeneous Poisson process as null model. Bivariate analysis and a toroidal shift null model were applied to test for independence between the spatial patterns of the two groups separately for each year, as well by exploring spatiotemporal patterns from different years. Results: In the first year Corynephorus and ,all other species' showed an aggregated pattern on a spatial scale > 40 cm and in the second and third years a significant attraction for distances between 4 and 12 cm, with an increasing radius in the third year. The analyses of interspecific spatiotemporal dynamics revealed a change from independence to attraction between distances of 4 cm and 16 cm when using Corynephorus as focal species. However, applying ,all other species' as focal points results in a significant attraction at distances up to 60 cm in the first year and a diminishing attraction in the second and third years with distances , 6 cm. Conclusions: Facilitative species-species interactions are present in early stages of primary succession, resulting mainly from pioneer species acting as physical barriers and their ability to capture diaspores being drifted by secondary dispersal along the substrate surface. However, due to gradual establishment of perennial species and their ability of lateral extension by vegetative dispersal, facilitation may influence spatial pattern formation predominantly on short temporal and fine spatial scales. [source] Rapid determination of rice seed vigour by spontaneous chemiluminescence and singlet oxygen generation during early imbibitionLUMINESCENCE: THE JOURNAL OF BIOLOGICAL AND CHEMICAL LUMINESCENCE, Issue 1 2003Wenli Chen Abstract Using a highly sensitive single photon counter, a spontaneous chemiluminescence (CL) study on rice (Oryza sativa L.) seeds stored in different years was carried out. We first observed that the degree of ageing in rice seeds was related to the intensity of spontaneous CL during early imbibition (0,30 min). Rice seeds stored for a shorter time had a stronger intensity of CL in early imbibition. The germination rate of rice seeds showed an obvious positive correlation with the intensity of spontaneous CL. Singlet oxygen (1O2) in rice seeds during early imbibition was investigated by a CL method using a cypridina luciferin analogue, 2-methyl-6-(p -methoxyphenyl)-3,7-dihydroimidazo [1,2,] pyrazin-3-one (MCLA), as a selective CL probe. Additional experimental evidence for the formation of 1O2 came from the quenching effect of sodium azide (NaN3) on MCLA-mediated rice seeds' CL. Analysis based on the experimental results demonstrated that spontaneous CL in rice seeds during early imbibition was mainly contributed by singlet oxygen (1O2). Copyright © 2002 John Wiley & Sons, Ltd. [source] Site fidelity and movements of humpback whales (Megaptera novaeangliae) on the Brazilian breeding ground, southwestern AtlanticMARINE MAMMAL SCIENCE, Issue 4 2010Leonardo L. Wedekin Abstract Site fidelity and movements were studied for humpback whales photo-identified from 1989 to 2006 in the Abrolhos Bank, southwestern Atlantic, Brazil. A total of 2,612 individuals were identified, 374 of which were observed on more than one occasion. The cumulative number of identified whales has increased since 1989. Recapture rate was low and varied among different years. A total of 33 whales was observed using the Abrolhos Bank for longer than 10 yr, up to a maximum of 16 yr. Our data suggest that different whales show distinct movement rates. Some whales used a large extent of the Abrolhos Bank region. Opportunistic photo-identification data (on the scale of the Brazilian coast from 4° to 23°S) revealed important information about stock identity. The longest distance between within-season resightings was over 600 km, while one whale was observed in two locations separated by more than 1,400 km in different years. Long-range movements within and between seasons support the single stock hypothesis for humpback whales wintering off the Brazilian coast. [source] Slipperiness on roads ,an expert system classificationMETEOROLOGICAL APPLICATIONS, Issue 1 2000Jonas Norrman A method for classifying different types of slipperiness on roads in Sweden is described. Using this method it is possible to survey road conditions in different areas and between different years to optimise winter road maintenance. Winter road maintenance in Sweden is generally undertaken by the national road administration to improve winter-time road conditions, thereby keeping up the traffic flow and decreasing the accident rate. As a number of different types of slipperiness may develop on roads in winter, each due to a specific set of meteorological variables, maintenance work can be a complicated task. With the proposed classification method it becomes easier for the winter maintenance personnel to analyse information on road conditions and survey the distribution of road slipperiness in a region. The classification is performed with an expert system using meteorological data from the Swedish Road Weather Information System. The road condition is classified as good or as one out of ten different types of slipperiness on roads. Road conditions during three different winter periods are analysed. The results show that variations in climate produce substantial differences in annual road condition characteristics. The output from the expert system classifying road slipperiness is compared with recorded winter road maintenance reports. Maintenance action took place on 49% of all occasions when road conditions were classified as slippery. Copyright © 2000 Royal Meteorological Society [source] Students' and Teachers' Assessments of the Need for Accuracy in the Oral Production of German as a Foreign LanguageMODERN LANGUAGE JOURNAL, Issue 4 2007MONIKA CHAVEZ Previous research indicates that foreign language learners are much more focused on accuracy, particularly grammatical accuracy, than their teachers are. The purpose of the current study was to gain a more detailed understanding of American learners' views of the need for accuracy in the oral production of a foreign language (German) by (a) distinguishing among 4 different purposes of language use (deriving a personal sense of accomplishment; being comprehensible to a native speaker [NS]; being pleasant to an NS; receiving an A in the course); (b) specifying 19 different language forms (grammatical, phonological, lexical, and pragmatic) of German; (c) asking the learners to assess the likelihood of ever attaining 90% or higher accuracy in each of these features; (d) examining learners in 4 different years of instruction; and (e) comparing the learners' beliefs to those of their teachers. The results revealed that (a) the learners in this study were not universally motivated toward accuracy in oral production generally or toward grammatical accuracy specifically; (b) they assumed that the grade requirements demanded much higher levels of accuracy than were necessary (as reported by the teachers) and were needed for communication with NSs or for their personal sense of accomplishment; (c) the year of instruction distinguished ratings of needed accuracy in specific forms, but not ratings of the overall degree of needed accuracy; and (d) the views of beginning learners especially and their teachers differed on the degree of accuracy needed to obtain a grade of A in the course, to derive a sense of accomplishment, and in the usage of specific language forms. Here, the learners appeared to construct unwarranted equivalencies between form-meaning relationships in the first language (L1) and the second language (L2) when they perceived that a low degree of accuracy was needed in certain German forms, particularly case endings and suprasegmental features. These findings suggest that judgments of required accuracy: (a) interact with the specific language-use purpose and specific language forms; (b) may vary by specific L1,L2 pairings; and (c) may have reflected in previous research the learners' perceptions of grade requirements rather than their true personal motivations. [source] Temporal patterns of genetic variation across a 9-year-old aerial seed bank of the shrub Banksia hookeriana (Proteaceae)MOLECULAR ECOLOGY, Issue 13 2005LUKE G. BARRETT Abstract The pattern of accumulation of genetic variation over time in seed banks is poorly understood. We examined the genetic structure of the aerial seed bank of Banksia hookeriana within a single 15-year-old population in fire-prone southwestern Australia, and compared genetic variation between adults and each year of a 9-year-old seed bank using amplified fragment length polymorphism (AFLP). B. hookeriana is well suited to the study of seed bank dynamics due to the canopy storage of its seeds, and because each annual crop can be identified. A total of 304 seeds from nine crop years and five maternal plants were genotyped, along with 113 plants from the adult population. Genetic variation, as assessed by the proportion of polymorphic markers (Pp) and Shannon's index (I), increased slightly within the seed bank over time, while gene diversity (Hj), did not change. Pp, I, and Hj all indicated that genetic variation within the seed bank quickly approached the maximal level detected. Analysis of molecular variance revealed that less than 4% of variation could be accounted for by variation among seeds produced in different years, whereas there was greater differentiation among maternal plants (12.7%), and among individual seeds produced by different maternal plants (83.4%). With increasing population age, offspring generated each year were slightly more outbred, as indicated by an increase in the mean number of nonmaternal markers per offspring. There were no significant differences for Hj or I between adults and the seed bank. Viability of seeds decreased with age, such that the viability of 9-year-old seeds was half that of 2-year-old seeds. These results suggest that variable fire frequencies have only limited potential to influence the amount of genetic variation stored within the seed bank of B. hookeriana. [source] Temporal and spatial variability in soil food web structureOIKOS, Issue 11 2007Matty P. Berg Heterogeneity is a prominent feature of most ecosystems. As a result of environmental heterogeneity the distribution of many soil organisms shows a temporal as well as horizontal and vertical spatial patterning. In spite of this, food webs are usually portrayed as static networks with highly aggregated trophic groups over broader scales of time and space. The variability in food web structure and its consequences have seldom been examined. Using data from a Scots pine forest soil in the Netherlands, we explored (1) the temporal and spatial variability of a detrital food web and its components, (2) the effect of taxonomic resolution on the perception of variability over time and across space, and (3) the importance of organic matter quality as an explanatory factor for variability in food web composition. Compositional variability, expressed using the Bray-Curtis similarity index, was measured over 2.5 years using a stratified litterbag design with three organic horizons per litterbag set. Variability in community composition and organic matter degradation increased over time in the litter horizon only. Seasonal variation in community composition was larger than variation between samples from the same season in different years. Horizontal spatial variability in community composition and organic matter degradation was relatively low, with no increase in variability with increasing distance between samples. Vertically, communities and organic matter degradation was more different between the non-adjacent litter and humus horizons than between adjacent layers. These findings imply that soil food webs, at least in temperate forest plantations, are more variable than is currently appreciated in experiments and model studies, and that organic matter turnover might be an important factor explaining variability in community composition. Species composition was more variable than functional group composition, which implies that aggregated food webs will seem less sensitive to local temporal and spatial changes than they in fact are. [source] The fluvial morphodynamics of two small permafrost drainage basins, Richardson Mountains, Northwestern CanadaPERMAFROST AND PERIGLACIAL PROCESSES, Issue 3 2002Dr Kuno Priesnitz Abstract Based on hydrological fieldwork in the tundra of northwestern Canada during the springs of 1986, 1990, 1992, and 1994 and the summers of 1998, 1999, and 2000 the paper deals with the fluvial processes induced by spring snowmelt and by summer rainfall in two small stream valleys. At the end of winter the floors of these flat-bottomed valleys are covered by icings (aufeis) over most of their length. The biggest quantity of meltwater runoff passes in an ice channel on top of the icing, with flow velocities up to 4.8 m/s. The main solid-sediment transport takes place through the short runoff interval, when the stream channel has entrenched the aufeis in some places. The calculated suspended load transport during snowmelt flood varied from 62,313 t/km2 in different years. In summer, suspended-sediment transport varies between 0.2,1.4 t/km2. There are no data about the frequency of exceptionally strong precipitation events, similar to those that occurred during the 1999 summer in the Douglas Creek basin that led to a suspended load transport of 153 t/km2 and a bedload transport of 444 t/km2 in about 12 days. The average annual suspended-sediment yield for Andy Creek is 71 t/km2/yr, and 328 t/km2/yr for Douglas Creek. The average annual solutes yield for Andy Creek is 19 t/km2/yr, and 52 t/km2/yr for Douglas Creek. If one includes the hardly-recordable bedload transport, the total equivalent surface lowering rate by fluvial solids transport is about 350 mm/1000yr for the Andy Creek basin and 850 mm/1000yr for the Douglas Creek basin. Copyright © 2002 John Wiley & Sons, Ltd. [source] Variation of Apigenin Quantity in Diploid and Tetraploid Chamomilla recutita (L.) RauschertPLANT BIOLOGY, Issue 4 2000vehlíková Abstract: Apigenin, a pharmacologically important flavonoid of the chamomile plant, was analyzed at two ploidy levels during a three-year period. This flavonoid accumulates in the ligulate florets of the anthodium. Higher percentages of apigenin were found in the ligulate florets of a diploid cultivar, in comparison with tetraploid plants. However, when the total apigenin (mg of compound) in the anthodium was evaluated, tetraploid individuals accumulated significantly more flavonoid. Moreover, in contrast to morphological quantitative characteristics of the anthodium, which varied significantly in different years, apigenin percentage in the ligulate florets was constant and not influenced by environmental conditions. Apigenin content was also found to change during inflorescence ontogeny. It represents the highest percentage of dry mass in young developing florets and anthodia of both cultivars. The total apigenin content of the anthodium, however, increases during flowering, although at later stages apigenin forms only a minor part of ligulate floret and anthodium dry mass. [source] A metabolomic study of substantial equivalence of field-grown genetically modified wheatPLANT BIOTECHNOLOGY JOURNAL, Issue 4 2006John M. Baker Summary The ,substantial equivalence' of three transgenic wheats expressing additional high-molecular-weight subunit genes and the corresponding parental lines (two lines plus a null transformant) was examined using metabolite profiling of samples grown in replicate field trials on two UK sites (Rothamsted, Hertfordshire and Long Ashton, near Bristol) for 3 years. Multivariate comparison of the proton nuclear magnetic resonance spectra of polar metabolites extracted with deuterated methanol,water showed a stronger influence of site and year than of genotype. Nevertheless, some separation between the transgenic and parental lines was observed, notably between the transgenic line B73-6-1 (which had the highest level of transgene expression) and its parental line L88-6. Comparison of the spectra showed that this separation resulted from increased levels of maltose and/or sucrose in this transgenic line, and that differences in free amino acids were also apparent. More detailed studies of the amino acid composition of material grown in 2000 were carried out using gas chromatography-mass spectrometry. The most noticeable difference was that the samples grown at Rothamsted consistently contained larger amounts of acidic amino acids (glutamic, aspartic) and their amides (glutamine, asparagine). In addition, the related lines, L88-6 and B73-6-1, both contained larger amounts of proline and ,-aminobutyric acid when grown at Long Ashton than at Rothamsted. The results clearly demonstrate that the environment affects the metabolome and that any differences between the control and transgenic lines are generally within the same range as the differences observed between the control lines grown on different sites and in different years. [source] | ||||||||||||||||||||||||||||||||||||||||