bluuebunny/crossref_metadata_2025_split huggingface dataset:
Waiting for service on the internet
Authors: Ryan Gerard , Valverde Mireia 
Published: April 2005

PurposeE‐consumers consistently complain that the internet is frustratingly slow. Most existing research on this phenomenon is based on the concept of “download delay”, that is, the time required for a web page to fully download to the e‐consumer's computer screen. This paper reports on an exploratory study of the phenomenon of waiting for service on the internet with the intention of extending the narrow conceptualisation of the phenomenon of “download delay” to a more user‐based perspective of waiting on the internet.Design/methodology/approachThe study is based on a qualitative research methodology. The research methods are seven asynchronous virtual focus groups involving 126 intensive internet users over 17 days and 92 participants who maintained personal diaries of waiting on the internet over a nine‐week period.FindingsA new definition of waiting on the internet is proposed based on extensive virtual focus group research. Subsequently, 14 distinct types of internet waiting situations are identified based on the analysis of a total of 1,041 waiting situations as reported by the participants in the study.Practical implicationsA number of practical implications for various functional areas of the business are outlined. Conceptual and methodological contributions are also made.Originality/valueThe study is the first to present a broader conceptualisation of waiting on the internet from an e‐consumer perspective and based on empirical research. All previous research has been based on just one type of online waiting, i.e. waiting for web pages to download to the user's screen. This paper presents 13 “new” types of waiting situations on the internet.
The effect of vertical migration strategy on retention and dispersion in the Irish Sea during spring–summer
Authors: EMSLEY S. M. , TARLING G. A. , BURROWS M. T. 
Published: April 2005

AbstractA biophysical model of the Irish Sea was produced to predict net horizontal movement of key taxa including small copepods (Acartia, Pseudocalanus), large copepod species (Calanus finmarchicus and C. helgolandicus), the euphausiid Meganyctiphanes norvegica, and the larval stages of commercially important fish and Nephrops. The model coupled biological information on the vertical distribution and diel vertical migration (DVM) of these taxa with temporally resolved flow fields generated by a baroclinic hydrodynamic model. The DVM of Calanus spp. and Meganyctiphanes was parameterized empirically from data provided by a biophysical campaign carried out in the nearby Clyde Sea. Small copepods and larvae remained within the layers above the thermocline. Model organisms, programmed with particular behavioural patterns, were spaced at regular intervals (1/20° longitude × 1/30° latitude) in the model grid, which extended from 53 to 54.5°N and 4.5 to 6.4°W. The model was run over the months of April, May and June. Model simulations showed that the movement of model organisms followed one of four characteristic patterns: containment along the coast, advection to the north or south, stagnation in the centre of the gyre or circulation around the periphery of the gyre. The latter pattern was apparent even in April, when gyral circulation was not expected because of a lack of stratification in the water column. Thirty‐day model runs in April, May and June showed that the number of organisms retained within the model grid varied between 23 and 49%. Those seeded close to the Irish coast had the highest probability of being retained within the model grid at the end of 90 days. DVM increased the probability of retention through improving the chances of organisms becoming entrained within the gyre circulation. This was especially true for Calanus spp., with those performing midnight sinking being the most likely to be retained out of any model organism. Meganyctiphanes showed comparatively lower levels of retention in deep regions, which suggests that they may have to swim against currents during certain phases of their DVM to avoid displacement. Overall, model results supported a number of hypotheses on the origin and fate of various taxa in the Irish Sea, as well as revealing some less expected distribution patterns.
Key factors influencing transport of white shrimp (Litopenaeus setiferus) post‐larvae into the Ossabaw Sound system, Georgia, USA
Authors: WENNER E. L. , KNOTT D. M. , BARANS C. A. , WILDE S. , BLANTON J. O. , AMFT J. 
Published: April 2005

AbstractWe examined conditions under which white shrimp (Litopenaeus setiferus) post‐larvae enter an estuarine channel receiving high freshwater discharge and one receiving negligible discharge in the Ossabaw Sound system of Georgia, USA, during 1997 and 1998. We used surface nets to collect plankton over several 14‐day periods, during which consecutive tows were made at night against the flooding current at stations in the inlet channels. During these sampling periods, additional intensive periods of around‐the‐clock surface and near‐bottom (using a bottom sled) plankton tows were made. Data on oceanographic conditions were obtained from moored instrument arrays and shipboard sampling. We identified three key factors that influenced the densities of post‐larval white shrimp in time and space within the Ossabaw inlet system. The first factor was a critical minimum temperature of coastal waters of 27–28°C. Once the threshold temperature was reached, lunar tidal stage became a key factor when the full duration of the flood tide coincided with darkness during peak ingress. This peak also coincided with an increase in water level within the system by more than 0.2 m, which induced an additional influx of water that reinforces the flood current over the ingress period. Our results suggest that the direction of subtidal currents (into or out of the system) becomes a significant factor in post‐larval ingress when influx of water coincides with the time of favorable temperature conditions and nighttime flood tides.
Trends in NE Atlantic landings (southern Portugal): identifying the relative importance of fisheries and environmental variables
Authors: ERZINI KARIM 
Published: April 2005

AbstractTime series of commercial landings from the Algarve (southern Portugal) from 1982 to 1999 were analyzed using min/max autocorrelation factor analysis (MAFA) and dynamic factor analysis (DFA). These techniques were used to identify trends and explore the relationships between the response variables (annual landings of 12 species) and explanatory variables [sea surface temperature, rainfall, an upwelling index, Guadiana river (south‐east Portugal) flow, the North Atlantic oscillation, the number of licensed fishing vessels and the number of commercial fishermen]. Landings were more highly correlated with non‐lagged environmental variables and in particular with Guadiana river flow. Both techniques gave coherent results, with the most important trend being a steady decline over time. A DFA model with two explanatory variables (Guadiana river flow and number of fishermen) and three common trends (smoothing functions over time) gave good fits to 10 of the 12 species. Results of other models indicated that river flow is the more important explanatory variable in this model. Changes in the mean flow and discharge regime of the Guadiana river resulting from the construction of the Alqueva dam, completed in 2002, are therefore likely to have a significant and deleterious impact on Algarve fisheries landings.
Effects of stream restoration on ecosystem functioning: detritus retentiveness and decomposition
Authors: LEPORI F. , PALM D. , MALMQVIST B. 
Published: April 2005

Summary

Increasing degradation of ecological conditions in streams because of human activities has prompted widespread restoration attempts; however, the ecological consequences of restoration remain poorly understood. We explored the effects of restoration through placement of boulders into the channel in the Ume River catchment in northern Sweden, where tributary streams were extensively channelized to facilitate the transport of timber in the 19th and early 20th centuries. Retentiveness and breakdown of coarse particulate organic matter (CPOM), two key ecological functions in low‐order streams most likely to be affected by channelization, were compared between restored, channelized and unimpacted reference stream sites.
Artificial leaves were used to assess short‐term CPOM retentiveness, while CPOM breakdown was estimated as the mass loss of alder (Alnus spp.) leaf packs placed in coarse mesh litter bags. Also, the taxonomic richness, abundance, biomass and evenness of the leaf‐eating invertebrates (shredders) on the retrieved leaf material were quantified. Detailed field measurements were carried out to identify geomorphological and hydraulic controls of CPOM retentiveness and breakdown at the study sites.
CPOM retentiveness reflected most strongly the density of boulders and submerged woody debris at the study sites. Restored sites were on average twice as retentive as channelized sites and significantly more retentive than reference sites when discharge was controlled.
Current velocity at bank‐full flow was the single most important predictor of CPOM mass loss, implying that mechanical fragmentation was substantial during high flows; other apparent controls of CPOM breakdown included water temperature and shredder abundance. CPOM mass loss was similar between restored and reference sites. However, breakdown was slightly faster at most channelized sites, consistent with higher hydraulic stress during high flow conditions. The shredder assemblages that colonized the litter bags were similar in richness, abundance, biomass and evenness between treatments.
Synthesis and applications. In channelized forest streams, low retentiveness and fast mechanical fragmentation during high flows contribute to the rapid depletion of benthic CPOM following leaf abscission in autumn, thereby weakening the heterotrophic energy pathways that probably support much of the biological production in these systems. Our results illustrate that restoration by replacement of boulders can successfully reverse these impacts of channelization and thus contribute to the efficient ecological functioning of impacted streams.
Succession of aquatic vegetation driven by reduced water‐level fluctuations in floodplain lakes
Authors: VAN GEEST G. J. , COOPS H. , ROIJACKERS R. M. M. , BUIJSE A. D. , SCHEFFER M. 
Published: April 2005

Summary

In recent years, interest has grown in restoring floodplain function of regulated rivers. Successful rehabilitation of riparian systems requires knowledge of how regulation of river flow affects biodiversity and ecosystem function. The effects of changes in the river's low water‐level regime on aquatic ecosystems in floodplains has received little attention so far.
The aquatic vegetation of 215 floodplain lakes along the Lower Rhine (the Netherlands) was analysed in relation to lake characteristics and lake water‐level fluctuations in 1999–2000.
Vegetation composition was related to lake morphology and age, cattle access to the shoreline, the amount of time the river was in flood, and lake sediment area exposed at low water level (drawdown). Surprisingly, vegetation composition was correlated more strongly with lake age and occurrence of drawdown than the amount of time the river was in flood.
In older lakes, water‐level fluctuations are reduced due to an accumulation of clay and silt that ‘seals’ sediment, preventing drawdown during periods of low river levels. Our results suggest that this clay sealing process is a major driving force for aquatic vegetation succession in floodplain lakes along the Lower Rhine, as succession drives from desiccation‐tolerant species (e.g. Chara spp.) in young lakes to desiccation‐sensitive species (e.g. Nuphar lutea) in old lakes.
Water levels were stable in lakes along a river branch that was impounded below mean flow only. Here, the original low water‐level regime has been replaced by an artificial regime with higher water levels than would be expected naturally. Consequently, in these lakes drawdown was rare or absent, and the aquatic macrophyte vegetation was characterized by low species richness and frequent dominance by the invasive species Elodea nuttallii.
Synthesis and applications. Our results show that stabilization of river water levels during low flow may negatively affect vegetation composition and succession in floodplain lakes adjacent to these rivers. A management scheme including incidental temporary lowering of the river water level, which results in drawdown of floodplain lakes, would enhance the ecological status of those rivers with stabilized water levels during low flow.
Population dynamics of brushtail possums subject to fertility control
Authors: RAMSEY DAVE 
Published: April 2005

Summary

Reducing the fertility of pest species using immunocontraceptive vaccines holds promise for the humane and effective control of vertebrate pest populations. However, despite much research into the development of contraceptive vaccines, there are few data illustrating the effectiveness of fertility control for managing wild populations of vertebrate pests.
In New Zealand, introduced brushtail possums Trichosurus vulpecula have been the focus for the development of contraceptive vaccines to provide a possible alternative to lethal control techniques.
The effect of fertility control on the population dynamics of brushtail possums was investigated experimentally using surgical sterilization to suppress breeding on six 12‐ha study sites between January 1996 and October 2000. Sterilization treatments, consisting of 0%, 50% and 80% of resident females sterilized, were applied at a particular site, with adjustments made annually on recruits to maintain levels of sterility. Mark–recapture trapping was used to estimate age‐specific demographic rates and their relative contribution to age‐specific population growth rates (λ).
Sterility treatments resulted in reductions to per capita rates of local recruitment (surviving young per adult female) of 60% and 74% on average for 50% and 80% levels of sterility, respectively. However, immigration by yearling‐aged possums compensated for reductions in local recruitment because of sterility treatments, leading to the stable (λ = 1) population trajectories on sterility treatment sites.
There was some evidence that sterilized females had higher annual survival rates than fertile females, but otherwise there was no evidence of any other compensatory responses to imposed sterility. However, additional studies are needed to clarify possible density‐dependent responses that could compensate for the effects of fertility control.
Synthesis and applications. Demographic compensation by pest populations can negate the effects of fertility control. Results from this study suggest that immigration can easily compensate for fertility control in pest species where adult survival is high and fecundity is low. This suggests that fertility control will need to be applied at large spatial scales to reduce this effect. Where adult survival makes a relatively high contribution to the population growth rate, the benefits of fertility control would be enhanced if integrated with conventional control to provide rapid initial population reduction.
Habitat selection by yellowhammers Emberiza citrinella on lowland farmland at two spatial scales: implications for conservation management
Authors: WHITTINGHAM MARK J. , SWETNAM RUTH D. , WILSON JEREMY D. , CHAMBERLAIN DAN E. , FRECKLETON ROBERT P. 
Published: April 2005

Summary

Yellowhammer Emberiza citrinella populations have declined rapidly in the UK over recent decades, and a clear understanding of their habitat requirements is important to help inform conservation schemes. We aimed to disentangle and rank the effects of winter versus breeding season habitat characteristics.
We used information theoretic methods to analyse the factors determining yellowhammer distribution across 26 sites in England and Wales. We did this at two spatial levels: individual field boundaries and individual territories, the latter consisting of spatial clusters of boundaries.
We considered the role of nine predictor variables, all of which have been suggested in the literature as potentially important. These comprised boundary height and width, and the presence of hedges, trees, ditches, boundary strips, tillage crops, winter set‐aside and winter stubbles.
The results of the statistical modelling showed that winter habitats play an important role in determining where birds locate territories in summer. In particular, the presence of rotational set‐aside fields in winter showed the strongest association with summer territories.
There were minor differences between the territory‐ and boundary‐based models. Most notably, the territory data demonstrated a strong preference for territories containing trees, but this was not observed in the boundary data set. We suggest that the differences between the models may reflect different scales of habitat selection. Boundary occupancy reflects broad distributions of habitat suitability; territory occupancy patterns better reveal detailed habitat requirements.
Regional densities were more closely correlated with the predictions of the boundary‐based model than those of the territory‐based model, and we discuss the implications of this for interpreting habitat association models.
Synthesis and applications. Provision of winter set‐aside fields for summer territory selection by yellowhammers is an important consideration for farm management where conservation is a priority. We show that models based on occupancy of individual boundary units (e.g. hedgerows) correlate with the density of territories at the farm scale; thus farm management practices link directly to population sizes through effects on the quality of breeding habitat.
Can we use the young : female ratio to infer ungulate population dynamics? An empirical test using red deerCervus elaphus as a model
Authors: BONENFANT CHRISTOPHE , GAILLARD JEAN‐MICHEL , KLEIN FRANÇOIS , HAMANN JEAN‐LUC 
Published: April 2005

SummaryManagement decisions for exploited species often rely on count ratios, such as the young to adult female ratio as a proxy of birth rate, and the decrease in the ratio between yearling and females in yeart+ 1 and the young : female ratio in yeartto obtain juvenile survival. However, the reliability of such estimates has yet to be demonstrated.We investigated the consistency of the young to female ratio method by using observations on individually marked female red deer. These females were known to have raised their calves to weaning successfully. We compared temporal variation in the proportion of females with a calf at heel from count ratios with the probability of observing a calf with its mother from marked animals.The proportion of females observed with a calf at heel decreased over time (from 0·43 early May to 0·15 early March). This measure was influenced by individual variation and by interactive effects of year and habitat type, although there was no direct relationship with the density of vegetation cover.The proportion of females seen with a calf at heel assessed from counts did not correspond with the probability of observing a female with a calf at heel, given that she successfully weaned a calf in autumn (estimated from direct observation). The probability of observing a female with a calf was highest in September (0·4) prior to the rut and lowest just after the birth season (0·08) and during the rut (0·18).The temporal pattern in the probability of observing a calf with its mother, given that she successfully weaned a calf, reflected changes in the mother–calf bond from birth to weaning, rather than changes in offspring mortality or changes in pregnancy rates. These variations in the probability of observing the mother–calf pair in the field may lead to strong biases in count ratio‐based methodologies.Synthesis and applications. This study has important implications for the management of ungulate populations when decisions are based on count ratios. Our results indicate that count‐based estimates of vital rates are misleading, especially in closed habitats. Pregnancy rate and juvenile survival rate are both key parameters in detecting density‐dependence responses. Reliable estimates of survival and pregnancy rates obtained from marked animals and foetus sampling are more accurate. Alternatively, yearly monitoring of young body mass or bone length coupled with an index of grazing pressure would improve the assessment of population dynamics.
Predicting plant species’ responses to river regulation: the role of water level fluctuations
Authors: LEYER ILONA 
Published: April 2005

Summary

One of the main targets of river regulation with dams and dykes is the stabilization of highly fluctuating water tables. While there is information about the overall impact of such regulation measures on plant species composition and richness, far less is known about specific species’ response patterns to reduced water level fluctuations.
The response of 30 common grassland species to soil moisture and water level fluctuations was assessed. Floristic data were collected from the floodplain of the Elbe River, Germany, from 182 plots, 99 within the recent floodplain and 83 in an older floodplain, separated from one another by dykes. Hydrological data were collected weekly over 2 years at 37 water level wells. Using logistic regression, the patterns of species’ responses to hydrological regulation were predicted.
The majority of species responded significantly to water level fluctuations. Species of high elevation habitats occurred at lower elevations where water level fluctuations were reduced, indicating increasing drought at high elevation habitats. However, species that occurred in floodplain depressions tended to shift from lower to higher elevations to avoid permanent inundation.
Almost half of the species showed a significant preference for either highly fluctuating water tables, characteristic of the recent floodplain, or for stable water tables, characteristic of the older floodplain. The probability of their occurrence was either reduced or increased along a gradient of reduced fluctuations. These species’ responses could be partly explained by altered flooding regimes, although other factors, such as disturbance and dispersal processes, were also involved.
Synthesis and applications. This study demonstrates that reduced water level fluctuations caused by the construction of dams and dykes lead to substantial changes in the spatial distribution of floodplain plant species and in species composition. The methodology reported here allows accurate prediction of shifts in floodplain vegetation in response to human‐induced alterations in floodplain landscapes. This can be used as a tool to assess river regulation measures and for floodplain restoration purposes, such as dyke relocations.