bluuebunny/crossref_metadata_2025_split huggingface dataset:
An Evaluation of Strategies and Professional Development Needs on Attendance Issues within an LEA
Authors: Reid Ken 
Published: February 2004

This is the first article to focus specifically on an evaluation of the existing strategic policies and related professional development needs on attendance within an LEA. Such evaluations are becoming more important as LEAs respond to their first ever OFSTED and prepare for follow‐up visits and/or second inspections. Recent evidence suggests that attendance issues are becoming central to overall outcomes in OFSTED visits and in their subsequent reports to LEAs.This paper outlines the evidence from recent international and British research, considers the national scene and role of the education welfare service and then examines existing practice on attendance within an LEA. The findings of an in‐depth investigation into attendance issues within the LEA are then presented followed by key recommendations, an analysis of professional training needs as well as providing evidence on the LEA's progress since these training needs have been fulfilled.
Movement and dispersal of the invasive signal crayfish Pacifastacus leniusculus in upland rivers
Authors: Bubb Damian H. , Thom Timothy J. , Lucas Martyn C. 
Published: February 2004

Summary1. The American signal crayfish Pacifastacus leniusculus, an invasive species widely introduced throughout Europe, is a major threat to native European crayfish species and is causing increasing concern because of its wide impact on aquatic ecosystems.2. Whilst various control and management methods have been proposed, very little is known about the factors influencing dispersal and movements of signal crayfish.3. Sixty‐four adult signal crayfish (carapace length 31.9–63.8 mm) were radiotagged in upland rivers in northern England, during four periods. Tracking was carried out at two sites, a low‐density establishing population and a high‐density established population. Tracking was carried out at both sites concurrently during midsummer (June to August 2002), during late summer (August to September 2001) at the low‐density population site and during autumn to winter (October to February 2000/01) at the high‐density population site.4. Maximum movement occurred during midsummer. Temperature appeared to be a major factor influencing the timing and extent of movements between tracking periods.5. The frequency distribution of the maximum distance moved upstream and downstream by radiotagged crayfish showed an inverse power relationship. The median maximal upstream and downstream distances moved were 13.5 m (range 0–283 m) and 15 m (range 0–417 m), respectively. There was a significant difference between the distributions of upstream and downstream ranges, with greater distances moved downstream.6. All downstream movements made by crayfish appeared to be active movements and not the result of passive movement during periods of high discharge. There was no apparent influence of size, sex or density on the amount of movement recorded.7. The study provides important information on the spatial and temporal behaviour of introduced crayfish in upland lotic systems. In contrast to lowland rivers, our results suggest that flow or gradient may influence the invasive potential of signal crayfish in an upstream direction in upland rivers.
Cyst bank life‐history model for a fairy shrimp from ephemeral ponds
Authors: Ripley Bonnie J. , Holtz Janette , Simovich Marie A. 
Published: February 2004

Summary1. Ephemeral wetland habitats provide a useful model system for studying how life‐history patterns enable populations to persist despite high environmental variation. One important life‐history trait of both plants and crustaceans in such habitats involves hatching/germination of only some of the eggs/seeds at any time. This bet‐hedging leads to the development of a bank composed of dormant propagules of many ages.2. The San Diego fairy shrimp, Branchinecta sandiegonensis (Crustacea: Anostraca), a dominant faunal element of ephemeral ponds in San Diego, California, is a suitable organism for studying the consequences of highly fluctuating environmental conditions. As a result of large‐scale habitat loss, the species is also endangered, and this motivated our specific study towards understanding the hatching dynamics of its egg bank for planning conservation efforts such as pool restoration and re‐creation.3. We formulated a matrix population model using egg age within the bank to study the relationship between adult survival and reproduction, and survival in and hatching from the egg bank. As vital rates for fairy shrimp are only poorly known, we generated 48 matrices with parameters encompassing ranges of likely values for the vital rates of B. sandiegonensis. We calculated population growth rates and eigenvalue elasticities both for a static model and a model with periodic reproductive failure.4. The model shows that in good filling events, population growth rate is very high and the egg bank is increased dramatically. While population growth rate is insensitive to long‐term survival in the egg bank in our static deterministic model, it becomes sensitive to survival in the egg bank when a regime of periodically failed reproductive events is imposed.5. Under favourable conditions, it was best for shrimp to hatch from eggs as soon as possible. However, under a regime where failed reproductive events were common, it was best to hatch after several pool fillings. Because conditions change from favourable to unfavourable unpredictably, variation in age within the egg bank appears to be critical for the persistence of the population. This attribute needs to be carefully considered when restoring or creating new pools for conservation purposes.
Dynamics and ecological significance of daily internal load of phosphorus in shallow Lake Balaton, Hungary
Authors: Istvánovics Vera , Osztoics András , Honti Márk 
Published: February 2004

Summary1. As supported by field data, turbidity recorded by light scattering sensors could reliably be converted into concentration of suspended particulate matter (SPM) and coefficient of vertical light attenuation (Kd) in Lake Balaton.2. Autocorrelation analysis revealed that proper determination of SPM concentration and Kd required daily sampling. To approximate daily rate of resuspension, 15 min or more frequent measurements were needed. Thus, routine monitoring provides very little insight into environmental variability of shallow lakes as habitats for phytoplankton.3. The internal P load was estimated from daily rate of resuspension and P desorption capacity of sediments. The latter was assumed to be proportionate to the potentially mobile inorganic P content of SPM. A comparison with net primary production and nutrient status of phytoplankton showed that the proposed method of estimating time series of internal P load captured seasonal trends.4. The daily rate of resuspension was high whereas that of internal P load was low in Lake Balaton relative to other shallow lakes. The latter reflects favourable behaviour of the calcite‐rich sediments. As a consequence, carrying capacity of Basin 1 of Lake Balaton was P‐determined.5. The timing of external and internal loads was radically different. While the former showed mostly seasonal changes, large pulses characterised the latter. As a consequence, internal load may supply more P to phytoplankton growth during the critical summer months than external load. However, the relative importance of these sources may show substantial interannual variability.6. Large resuspension events often followed each other during periods of 10–15 days. It has been shown that disturbances in this frequency range are of key importance in maintaining the diversity of phytoplankton. We propose that resuspension can be perceived not only as a disturbance factor but also as a factor that periodically relaxes nutrient stress. The former feature may dominate the instantaneous effect, whereas the latter may determine the persistent effect of resuspension on succession of phytoplankton.
Predation impact of Leptodora kindtii on population dynamics and morphology of Bosmina fatalis and B. longirostris in mesocosms
Authors: Chang Kwang‐Hyeon , Hanazato Takayuki 
Published: February 2004

Summary1. We assessed the impact of predation by the invertebrate predator Leptodora kindtii on Bosmina longirostris and B. fatalis, which show seasonal and reciprocal succession patterns in Lake Suwa, in a mesocosm experiment using 20‐L tanks with or without the predator under different food conditions. We also analysed morphological responses of the two Bosmina species to the predator in the tanks.2. Bosmina fatalis dominated B. longirostris regardless of predator presence under high food density. However, the presence of Leptodora induced the dominance of B. fatalis more rapidly than its absence. On the contrary, no dominance of B. fatalis was observed in tanks with low food density, irrespective of the presence of the predator. Only B. fatalis showed morphological changes in response to the presence of Leptodora.3. Mucrone length and antennule shape (angle between body and antennule and angle between antennules) showed marked responses at both high and low food densities, but antennule length responded only at high food density. Mucrone length seems to be a more effective defence against Leptodora.4. The results suggest that B. fatalis is a superior competitor against B. longirostris and is more resistant to Leptodora predation, especially in good food conditions. The repeatedly observed seasonal succession of the two Bosmina species in the eutrophic Lake Suwa – the replacement of B. longirostris by B. fatalis following the occurrence of abundant Leptodora– seems to be caused by the selective predation of Leptodora on B. longirostris as well as the competitive ability of B. fatalis.
Factors regulating recruitment from the sediment to the water column in the bloom‐forming cyanobacterium Gloeotrichia echinulata
Authors: Karlsson‐Elfgren Irene , Rengefors Karin , Gustafsson Susanne 
Published: February 2004

Summary1. The influence of light, temperature, sediment mixing and sediment origin (water depth) on the recruitment of the cyanobacterium Gloeotrichia echinulata was examined in the laboratory.2. Light and temperature were the most important factors initiating germination in G. echinulata.3. The extent of germination (recruited biovolume) was mainly regulated by temperature and sediment mixing. Furthermore, sediment mixing significantly enhanced the frequency of observed heterocysts and colonies.4. Despite the fact that the deep and shallow sediments contained a similar number of akinete colonies, the highest recruitment occurred from shallow sediments, indicating that akinetes from shallow sediments have a higher viability than those from deeper parts of the lake.5. Our results support the hypothesis that shallow sediments are more important than profundal sediments for the recruitment of G. echinulata to the pelagic zone.
An HPLC analysis of the summer phytoplankton assemblage in Lake Baikal
Authors: Fietz Susanne , Nicklisch Andreas 
Published: February 2004

Summary1. The enormous size and spatial heterogeneity of Lake Baikal require rapid methods for large sample sets. We therefore tested the applicability of a novel, high‐performance liquid chromatography (HPLC)‐based, combination of methods for analysing phytoplankton. In July 2001, samples were collected in a transect across the lake at various depths down to 30 m. Phytoplankton (>3 μm) and autotrophic picoplankton (APP) were counted under light and epifluorescence microscopes, respectively. Pigments were analysed with HPLC.2. The pigment data allowed the contributions of the dominant phytoplankton groups to the total chlorophylla(Chla) in the lake to be estimated by multiple linear regression and by the CHEMTAX matrix factorisation program. Three marker pigments, fucoxanthin, lutein and zeaxanthin, were shown to be useful indicators of the abundance and spatial distribution of certain phytoplankton groups. The relative contributions of the various phytoplankton groups to the total Chlain the lake determined using these marker pigments were similar, but not identical, to those determined by cell counts.3. Pigment analyses of isolated strains from Lake Baikal and some European lakes confirmed that phycoerythrin‐containing Cyanobacteria with very high amounts of zeaxanthin were responsible for the low Chla/zeaxanthin ratios of the water samples. A picoplanktonic species of Eustigmatophyceae was isolated from the lake. Its high violaxanthin content, responsible for very low Chla/violaxanthin ratios of some water samples, can be used to estimate the contribution of this group to total Chla.
Salinity tolerance of diapausing eggs of freshwater zooplankton
Authors: Bailey Sarah A. , Duggan Ian C. , van Overdijk Colin D.A. , Johengen Thomas H. , Reid David F. , MacIsaac Hugh J. 
Published: February 2004

Summary1. Many freshwater zooplankton produce diapausing eggs capable of withstanding periods of adverse environmental conditions, such as anoxia, drought and extreme temperature. These eggs may also allow oligostenohaline species to survive increased salinity during periods of tidal flux or evaporation, and here we test the ability of diapause eggs to withstand such conditions.2. Salinity tolerance may also enable organisms to invade new environments. The increased rate of introduction of non‐indigenous species to the Laurentian Great Lakes since 1989, when ballast water exchange regulations (to replace fresh/brackish water at sea with full seawater) were first implemented for transoceanic vessels, has stimulated studies that explore mechanisms of introduction, other than of active animals, in ballast water. One hypothesis proposes that freshwater organisms transported in ballast tanks as diapausing eggs may be partially responsible for the increased rate of species introduction, as these eggs may tolerate a wide array of adverse environmental conditions, including exposure to saline water.3. We collected ballast sediments from transoceanic vessels entering the Great Lakes, isolated diapausing eggs of three species (Bosmina liederi, Daphnia longiremis and Brachionus calyciflorus), and measured the effect of salinity on hatching rate. In general, exposure to salinity significantly reduced the hatching rate of diapausing eggs. However, as non‐indigenous species can establish from a small founding population, it is unclear whether salinity exposure will be effective as a management tool.
Salinity, depth and the structure and composition of microbial mats in continental Antarctic lakes
Authors: Sabbe Koen , Hodgson Dominic A. , Verleyen Elie , Taton Arnaud , Wilmotte Annick , Vanhoutte Koenraad , Vyverman Wim 
Published: February 2004

Summary1. Lakes and ponds in the Larsemann Hills and Bølingen Islands (East‐Antarctica) were characterised by cyanobacteria‐dominated, benthic microbial mats. A 56‐lake dataset representing the limnological diversity among the more than 150 lakes and ponds in the region was developed to identify and quantify the abiotic conditions associated with cyanobacterial and diatom communities.2. Limnological diversity in the lakes of the Larsemann Hills and Bølingen Islands was associated primarily with conductivity and conductivity‐related variables (concentrations of major ions and alkalinity), and variation in lake morphometry (depth, catchment and lake area). Low concentrations of pigments, phosphate, nitrogen, DOC and TOC in the water column of most lakes suggest extremely low water column productivity and hence high water clarity, and may thus contribute to the ecological success of benthic microbial mats in this region.3. Benthic communities consisted of prostrate and sometimes finely laminated mats, flake mats, epilithic and interstitial microbial mats. Mat physiognomy and carotenoid/chlorophyll ratios were strongly related to lake depth, but not to conductivity.4. Morphological‐taxonomic analyses revealed the presence of 26 diatom morphospecies and 33 cyanobacterial morphotypes. Mats of shallow lakes (interstitial and flake mats) and those of deeper lakes (prostrate mats) were characterised by different dominant cyanobacterial morphotypes. No relationship was found between the distribution of these morphotypes and conductivity. In contrast, variation in diatom species composition was strongly related to both lake depth and conductivity. Shallow ponds were mainly characterised by aerial diatoms (e.g. Diadesmis cf. perpusilla and Hantzschia spp.). In deep lakes, communities were dominated by Psammothidium abundans and Stauroforma inermis. Lakes with conductivities higher than ±1.5 mS cm−1 became susceptible to freezing out of salts and hence pronounced conductivity fluctuations. In these lakes P. abundans and S. inermis were replaced by Amphora veneta. Stomatocysts were important only in shallow freshwater lakes.5. Ice cover influenced microbial mat structure and composition both directly by physical disturbance in shallow lakes and by influencing light availability in deeper lakes, as well as indirectly by generating conductivity increases and promoting the development of seasonal anoxia.6. The relationships between diatom species composition and conductivity, and diatom species composition and depth, were statistically significant. Transfer functions based on these data can therefore be used in paleolimnological reconstruction to infer changes in the precipitation–evaporation balance in continental Antarctic lakes.
Seasonal patterns of sediment loading and benthic invertebrate community dynamics in Lake Tanganyika, Africa
Authors: Donohue Ian , Irvine Kenneth 
Published: February 2004

Summary1. This study investigated the spatiotemporal dynamics of benthic invertebrate communities located close to the mouths of the Kalambo and Lunzua Rivers, at the southern end of Lake Tanganyika, and subject to varying degrees of sediment load.2. Metrics of exposure to riverine sediments were associated inversely with abundance and diversity of benthic organisms at sampling locations adjacent to both river mouths, indicating a major effect of riverine sediments on the structure of near‐shore benthic communities.3. A lower abundance of benthos was found at the mouth of the Lunzua River, which exports significantly higher sediment loads than the Kalambo.4. Seasonal cycles of abundance and diversity in the benthos varied with distance from river mouths. This has important implications for monitoring programmes investigating benthic communities close to the mouths of rivers.5. Our findings suggest that recent increases in the sediment loading of Lake Tanganyika, owing to anthropogenic catchment disturbance, impact significantly on biological diversity throughout the lake littoral, which provides habitat for the majority of species in the lake.
Variation in P‐content in aquatic plant tissues offers an efficient tool for determining plant growth strategies along a resource gradient
Authors: Garbey C. , Murphy K.J. , Thiébaut G. , Muller S. 
Published: February 2004

Summary1. The application of functional ecology models to aquatic plants often relies on morphological and life‐history traits which may reflect, in part, the phenotypic plasticity displayed by aquatic plants. The present study was designed to evaluate the use of physiological traits, such as nutrition patterns, to describe aquatic plant strategies along a gradient of increasing resource availablity.2. Taking phosphorus (P) as an example, nutrition‐use efficiencies were evaluated in five species, through the P‐content in plant tissues, the variations in P‐content according to nutrient availability and the perenniality of P‐storage. Plasticity in P‐storage was also investigated in Ranunculus peltatus, a morphologically highly plastic species.3. In 2001, P‐content was analysed in Callitriche hamulata, C. obtusangula, C. platycarpa, Elodea nuttallii and R. peltatus tissue samples. These five species were sampled at nine different sites in streams along an increasing resource gradient in the Northern Vosges Biosphere Reserve (NE France). Variations of P‐content in the roots, stems and dissected and floating leaves of R. peltatus were also studied.4. Only C. platycarpa and R. peltatus were found to occur in low nutrient availability conditions. Callitriche hamulata, C. obtusangula and E. nuttallii were restricted to mesotrophic and eutrophic sites. The highest nutrient‐use efficiency was found for E. nuttallii which was able to adapt its P‐storage to varying resource availabilities. Ranunculus peltatus was able to store high concentrations of P, but its P‐integration within the vegetative structure was less efficient under eutrophic conditions. Callitriche spp. appeared to have relatively low nutrient‐use efficiencies, although C. obtusangula displayed a high P‐content. While P was stored preferentially in roots in R. peltatus populations occurring in nutrient‐rich sites, there was no particular P‐storage organ for populations from nutrient‐poor sites.5. On the basis of P‐usage, R. peltatus and E. nuttallii presented competitor traits, C. hamulata and C. platycarpa displayed stress‐tolerant nutrient signatures and for C. obtusangula, ruderal or competitor characteristics dominated. The use of physiological traits, such as nutrition patterns, may provide valuable, complementary information about aquatic plant strategies, independent from the influence of morphological trait plasticity often displayed by these plants.
Physico‐chemical properties of flour and starch from jackfruit seeds (Artocarpus heterophyllus Lam.) compared with modified starches
Authors: Mukprasirt Amornrat , Sajjaanantakul Kamontip 
Published: February 2004

SummaryJackfruit (Artocarpus heterophyllus Lam.) is one of the most popular tropical fruits grown in Asia. The objective of this study was to compare physico‐chemical properties of native flour and starch from jackfruit seeds (A. heterophyllus) to commercially modified starches (Novation 2300 and Purity 4). The colour of jackfruit seed starch was lighter than the Novation 2300 starch but darker than the Purity 4 starch. The jackfruit seed starch had a narrower gelatinization temperature range than Purity 4 and required less gelatinization energy compared with modified starches. The peak viscosity of jackfruit seed starch was lower than commercially modified starches. Likewise, setback viscosity, swelling power and solubility of jackfruit seed starch showed similar trends. Results from this study suggest that native starch from jackfruit seed could be used as an alternative for modified starches in a system needing starch with a high thermal and/or mechanical shear stability.
Pulsed‐vacuum immersion of chicken meat and skin in acid solutions. Effects on mass transfers, colour and microbial quality
Authors: Deumier François 
Published: February 2004

SummaryDecontaminating chicken skin by immersion in an organic acid solution at low temperature (7 °C) led to 3.7, 2.5, 2.4 and 2.0 decimal reductions in total viable counts, Enterobacteriaceae, total coliforms and Escherichia coli, respectively. Lactic acid was a more effective decontaminating agent than citric acid. This decontaminating effect was very closely correlated with solution pH and chicken‐skin pH variations. The use of pulsed vacuum immersion (PVI) increased mass transfers (water gain and acidification) and the decontamination effect, especially with respect to total viable counts. In PVI conditions, the skin‐solution contact area was increased as a result of solution infiltration into microfolds and feather follicles, but the skin colour was modified (yellowing and greening) as the intensity of the acid treatment increased. In contrast, the results of a triangular test revealed that chicken sausages produced with acid‐treated skins did not differ from those made with untreated skins.