bluuebunny/crossref_metadata_2025_split huggingface dataset:
Stream fish assemblage and habitat structure in a tropical African river basin (Nyagui River, Zimbabwe)
Authors: Kadye Wilbert T. , Moyo Ngonidzashe A. G. 
Published: October 2007

AbstractFew studies have been carried out on stream ecology in southern Africa although many species are endangered. This study investigated the stream fish assemblage and their habitat associations over a period of 3 months (October 2004 to January 2005), in view of the proposal to build a dam across the Nyagui River. Twenty‐four fish species were collected and were separated into groups based on preferred microhabitats. The first group, dominated by Barbus paludinosus, comprised species collected from the upstream stations with slow flow, shallow depth (pools) and fine substrate type. Species associated with riffles, which included Chiloglanis neumanni, Labeobarbus marequensis and Opsaridium zambezense, comprised the second group on the downstream. The last group comprised species preferring pools with rock substrate and slow flow such as Pharyngochromis acuticeps and Pseudocranilabrus philander. The species were consistently associated with their habitat types throughout the sampling period. This relationship may be explained by the fish’s morphological adaptations. Species richness increased from nine in the upstream section to twenty in the downstream section and this was related to increasing habitat complexity downstream. The construction of the Kunzvi Dam across the Nyagui River is likely to lead to loss of rheophilic species while cichlids and introduced species may increase.
Contrasting transient and steady‐state rivers crossing active normal faults: new field observations from the Central Apennines, Italy
Authors: Whittaker Alexander C. , Cowie Patience A. , Attal Mikaël , Tucker Gregory E. , Roberts Gerald P. 
Published: October 2007

ABSTRACTWe present detailed data on channel morphology, valley width and grain size for three bedrock rivers crossing active normal faults which differ in their rate, history and spatial distribution of uplift. We evaluate the extent to which downstream changes in unit stream power correlate with footwall uplift, and use this information to identify which of the channels are likely to be undergoing a transient response to tectonics, and hence clarify the key geomorphic features associated with this signal. We demonstrate that rivers responding transiently to fault slip‐rate increase are characterised by significant long‐profile convexities (over‐steepened reaches), a loss of hydraulic scaling, channel aspect ratios which are a strong non‐linear function of slope, narrow valley widths, elevated coarse‐fraction grain‐sizes and reduced downstream variability in channel planform geometry. We are also able to quantify the steady‐state configurations of channels, that have adjusted to differing spatial uplift fields. The results challenge the application of steady‐state paradigms to transient settings and show that assumptions of power‐law width scaling are inappropriate for rivers, that have not reached topographic steady state, whatever exponent is used. We also evaluate the likely evolution of bedrock channels responding transiently to fault acceleration and show that the headwaters are vulnerable to beheading if the rate of over‐steepened reach migration is low. We estimate that in this setting the response timescale to eliminate long‐profile convexity for these channels is ∼1 Myr, and that typical hydraulic scaling is regained within 3 Myr.
Gene expression profiling of CD34+ cells in patients with the 5q− syndrome
Authors: Boultwood Jacqueline , Pellagatti Andrea , Cattan Helen , Lawrie Charles H. , Giagounidis Aristoteles , Malcovati Luca , Porta Matteo G. Della , Jädersten Martin , Killick Sally , Fidler Carrie , Cazzola Mario , Hellström‐Lindberg Eva , Wainscoat James S. 
Published: October 2007

SummaryThe transcriptome of the CD34+ cells was determined in a group of 10 patients with the 5q− syndrome using a comprehensive array platform, and was compared with the transcriptome of CD34+ cells from 16 healthy control subjects and 14 patients with refractory anaemia and a normal karyotype. The majority of the genes assigned to the commonly deleted region (CDR) of the 5q− syndrome at 5q31–q32 showed a reduction in expression levels in patients with the 5q− syndrome, consistent with the loss of one allele. Candidate genes showing haploinsufficiency in the 5q− syndrome included the tumour suppressor gene SPARC and RPS14, a component of the 40S ribosomal subunit. Two genes mapping to the CDR, RBM22 and CSNK1A1, showed a >50% reduction in gene expression, consistent with the downregulation of the remaining allele. This study identified several significantly deregulated gene pathways in patients with the 5q− syndrome and gene pathway analysis data supports the proposal that SPARC may play a role in the pathogenesis of the 5q− syndrome. This study suggests that several of the genes mapping to the CDR of the 5q− syndrome play a role in the pathogenesis of this disorder.
The plant mannose‐binding lectin NTL preserves cord blood haematopoietic stem/progenitor cells in long‐term culture and enhances their ex vivo expansion
Authors: Li Karen , Ooi Vincent E. C. , Chuen Carmen Ka Yee , Lam Audrey Carmen , Ooi Linda Shiou Mei , Zhang Xiao Bing , Tsang Kam Sze , Chiu Lawrence Chi Ming , Chan Kathy Yuen Yee , Li Chi Kong , Fok Tai Fai , Yuen Patrick Man Pan , Ng Pak Cheung 
Published: October 2007

Summary Ex vivo expansion of haematopoietic stem and progenitor cells in cytokine combinations is effective in promoting differentiation and proliferation of multilineage progenitor cells, but often results in reduction of self‐renewable stem cells. This study investigated the effect of a mannose‐binding lectin, NTL, purified from Narcissus tazetta var. chinensis, on prolonged maintenance and expansion of cord blood CD34+ cells. Our results showed that the presence of NTL or Flt‐3 ligand (FL) significantly preserved a population of early stem/progenitor cells in a serum‐ and cytokine‐free culture for 35 d. The effect of NTL on the ex vivo expansion of CD34+ cells in the presence of stem cell factor, thrombopoietin (TPO) and FL was also investigated. NTL‐enhanced expansion of early progenitors (CD34+, CD34+CD38−, mixed colony‐forming units and CFU‐GEMM) and committed progenitor cells (granulocyte CFU, erythroid burst‐forming units/CFU and megakayocyte CFU) after 8 and 12 d of culture. Six weeks after transplanting 12 d‐expanded cells to non‐obese diabetic severe combined immunodeficient mice, increased engraftment of human CD45+ cells was observed in the bone marrow of animals that received NTL‐treated cells. The dual functions of NTL on long‐term preservation and expansion of early stem/multilineage progenitor cells could be developed for applications in various cell therapy strategies, such as the clinical expansion of CD34+ cells for transplantation.
Impacts of Argentine ants on mealybugs and their natural enemies in California’s coastal vineyards
Authors: DAANE KENT M. , SIME KAREN R. , FALLON JULIE , COOPER MONICA L. 
Published: October 2007

Abstract 1. The Argentine ant, Linepithema humile, tends honeydew‐excreting homopterans and can disrupt the activity of their natural enemies. This mutualism is often cited for increases in homopteran densities; however, the ant’s impact on natural enemies may be only one of several effects of ant tending that alters insect densities. To test for the variable impacts of ants, mealybug and natural enemy densities were monitored on ant‐tended and ant‐excluded vines in two California vineyard regions.2. Ant tending increased densities of the obscure mealybug, Pseudococcus viburni, and lowered densities of its encyrtid parasitoids Pseudaphycus flavidulus and Leptomastix epona. Differences in parasitoid recovery rates suggest that P. flavidulus was better able to forage on ant‐tended vines than L. epona.3. Densities of a coccinellid predator, Cryptolaemus montrouzieri, were higher on ant‐tended vines, where there were more mealybugs. Together with behavioural observations, the results showed that this predator can forage in patches of ant‐tended mealybugs, and that it effectively mimics mealybugs to avoid disturbance by ants.4. Ant tending increased densities of the grape mealybug, Pseudococcus maritimus, by increasing the number of surviving first‐instar mealybugs. Parasitoids were nearly absent from the vineyard infested with P. maritimus. Therefore, ants improved either mealybug habitat or fitness.5. There was no difference in mealybug distribution or seasonal development patterns on ant‐tended and ant‐excluded vines, indicating that ants did not move mealybugs to better feeding locations or create a spatial refuge from natural enemies.6. Results showed that while Argentine ants were clearly associated with increased mealybug densities, it is not a simple matter of disrupting natural enemies. Instead, ant tending includes benefits independent of the effect on natural enemies. Moreover, the effects on different natural enemy species varied, as some species thrive in the presence of ants.
Change in the distribution of a member of the strand line community: the seaweed fly (Diptera: Coelopidae)
Authors: EDWARD DOMINIC A. , BLYTH JENNIFER E. , MCKEE RODERICK , GILBURN ANDRÉ SIMON 
Published: October 2007

Abstract 1. Coastal organisms are predicted to be particularly susceptible to the impact of global warming. In this study the distribution and relative abundance of two coastal invertebrates, Coelopa frigida (Fabricius) and C. pilipes are investigated.2. Coelopa pilipes has a more southerly distribution than C. frigida, and prefers a warmer climate. Coelopa pilipes is less resistant to sub‐zero temperatures than C. frigida and its northerly distribution is probably limited by cold winter days.3. The most recent distribution map of C. frigida and C. pilipes in northern Europe was published a decade ago and showed the northerly extent of the distribution of C. pilipes reaching the north coast of mainland Scotland but its complete absence from the Western and Northern Isles.4. C. pilipes has now spread throughout the Western Isles and the Orkney Islands but is still absent from Shetland. There has also been an increase in the relative frequency of C. pilipes at sites harbouring coelopids on the British mainland. A similar pattern of distribution change along the west coast of Sweden is reported.5. It is proposed that these changes have occurred primarily as a result of global warming and in particular due to the recent increase in winter temperatures. A number of other indirect effects may have also contributed to these changes, including a probable change in macroalgae distribution. The implications of these changes for the wrack bed ecosystem and at higher trophic levels are considered.
Nutrient dependent effects of consumer identity and diversity on freshwater ecosystem function
Authors: DZIALOWSKI ANDREW R. , SMITH VAL H. 
Published: October 2007

Summary1. Over the past decade, ecologists have tried to determine how changes in species composition and diversity affect ecosystem structure and function. Until recently, the majority of these studies have been conducted in terrestrial ecosystems and have not taken into account environmental variability. The purpose of this research was to determine how species identity and diversity in the freshwater zooplankton affected biomass of algae and zooplankton at two levels of nutrient enrichment.2. Several species of cladocerans were grown alone and together in microcosms at both ambient and raised phosphorus concentrations to determine if the effects of consumer identity and diversity were nutrient dependent.3. Total zooplankton biomass was greater, while algal biomass was lower, in mixed culture than in monoculture. The effects of zooplankton diversity on algal biomass, however, were only observed at raised phosphorus concentrations, suggesting that diversity effects were nutrient dependent. Specifically, diversity effects appeared to be related with biological mechanisms such as complementarity in resource use and/or facilitation.4. More diverse communities of zooplankton appear to be better able to control algae than single species of zooplankton at high nutrient concentrations; therefore, zooplankton diversity may provide a buffer against eutrophication in freshwater ecosystems.
Phosphorus and light colimit periphyton growth at subsaturating irradiances
Authors: HILL WALTER R. , FANTA SHARI E. 
Published: October 2007

Summary1. This study investigated the combined effects of light and phosphorus on the growth and phosphorus content of periphyton. To investigate the potential for colimitation of algal growth by these two resources, diatom‐dominated periphyton communities in large flow‐through laboratory streams were exposed under controlled conditions to simultaneous gradients of light and phosphorus.2. Periphyton growth rate was predictably light‐limited by the subsaturating irradiances (12–88 μmol photons m−2 s−1) used in this experiment. However, phosphorus concentration also limited growth rate: growth increased hyperbolically with increasing soluble reactive phosphorus (SRP), reaching a threshold of growth saturation between 22 and 82 μg L−1.3. Periphyton phosphorus content was strongly and nonlinearly related with SRP, reaching a maximum at 82 μg L−1SRP. Contrary to the Light : Nutrient Hypothesis, periphyton phosphorus content did not decrease with increasing light, even at the lowest concentrations of SRP. Periphyton phosphorus was highly correlated with periphyton growth rate (Spearman'sρ = 0.63,P < 0.005).4. Multiple regression analysis reinforced evidence of simultaneous light and phosphorus limitation. Both light and periphyton phosphorus content were significant variables in multiple regressions with growth parameters as dependent variables. Light alone accounted for 67% of the variance in periphyton biomass, and the addition of periphyton phosphorus as an additional independent variable increased the total amount of variance explained to 81%.5. Our results did not support the hypothesis that extra phosphorus is required for photoacclimation to low light levels. Rather, the effect of additional phosphorus may have been to accommodate increased requirements for P‐rich ribosomal RNA when growth was stimulated by increased light. The potential colimitation of periphyton growth by phosphorus and light at subsaturating irradiances has important implications in both theoretical and applied aquatic ecology.
European‐wide GIS‐based modelling system for quantifying the feedstock from Miscanthus and the potential contribution to renewable energy targets
Authors: STAMPFL PAUL F. , CLIFTON‐BROWN JOHN C. , JONES MICHAEL B. 
Published: October 2007

AbstractReliable estimates of feedstock resources are a prerequisite to the establishment of a biomass based‐industry for energy and non food products. Field trials in the European Union (EU) show that Miscanthus spp. can produce high yields. Here we use a model (MISCANMOD) coupled with a GIS environment to estimate the contribution that Miscanthus could make to projected national electricity consumption. We describe the integration of different data sets, transformation procedures, and spatial analyses using GIS to produce energy statistics for the EU‐25. Overall, Miscanthus grown on the 10% of arable land which is currently in set‐aside could generate 282 TWh yr−1 electricity. This would meet 39% of the EU‐25 target of 723 TWh yr−1 of electricity from renewable energy sources (RES) by 2010. As RES targets rise, land available for energy crops is also expected to increase. We consider three additional scenarios where Miscanthus could be grown on 10%, 20% and 35% of all agricultural land and we estimate it could generate respectively 345, 691 and 1209 TWh yr−1 of electrical energy. At a national scale France, Poland and Germany have the highest potentials for Miscanthus production based on agricultural land area (respectively 83, 52, 49 TWh yr−1 when 10% agricultural land is used). Finally, we reduced the scale to the EU NUTS2 (Nomenclature of Territorial Units for Statistics) regions to examine regional generation capacities. Key regions have been identified where national RES targets are exceeded. These regions could become net exporters of renewable energy.
Predicting potential impacts of climate change on the geographical distribution of enchytraeids: a meta‐analysis approach
Authors: BRIONES MARÍA JESÚS I. , INESON PHIL , HEINEMEYER ANDREAS 
Published: October 2007

AbstractThe expectation that atmospheric warming will be most pronounced at higher latitudes means that Arctic and montane systems, with predominantly organic soils, will be particularly influenced by climate change. One group of soil fauna, the enchytraeids, is commonly the major soil faunal component in specific biomes, frequently exceeding above‐ground fauna in biomass terms. These organisms have a crucial role in carbon turnover in organic rich soils and seem particularly sensitive to temperature changes. In order to predict the impacts of climate change on this important group of soil organisms we reviewed data from 44 published papers using a combination of conventional statistical techniques and meta‐analysis. We focused on the effects of abiotic factors on total numbers of enchytraeids (a total of 611 observations) and, more specifically, concentrated on total numbers, vertical distribution and age groupings of the well‐studied speciesCognettia sphagnetorum(228 observations). The results highlight the importance of climatic factors, together with vegetation and soil type in determining global enchytraeid distribution; in particular, cold and wet environments with mild summers are consistently linked to greater densities of enchytraeids. Based on the upper temperature distribution limits reported in the literature, and identified from our meta‐analyses, we also examined the probable future geographical limits of enchytraeid distribution in response to predicted global temperature changes using the HadCM3 model climate output for the period between 2010 and 2100. Based on the existing data we identify that a maximum mean annual temperature threshold of 16 °C could be a critical limit for present distribution of field populations, above which their presence would decline markedly, with certain key species, such asC. sphagnetorum, being totally lost from specific regions. We discuss the potential implications for carbon turnover in these organic soils where these organisms currently dominate and, consequently, their future role as C sink/source in response to climate change.
Climate change impacts on structure and diversity of fish communities in rivers
Authors: DAUFRESNE MARTIN , BOËT PHILIPPE 
Published: October 2007

AbstractIt is widely accepted that climate change constrains biota. Yet, because of the lack of consistent multisite and multitaxon surveys, few studies have addressed general rules about how climate change impacts on structure and diversity of animal communities. Especially, the relative influence of nonclimatic anthropogenic disturbances on this impact is fairly unknown. Here, we present for the first time a meta‐analysis assessing the effect of global warming on stream organisms. Fish communities of large rivers in France undergoing various anthropogenic pressures showed significant increase in proportions of warm‐water species and of specific richness during the last 15–25 years. Conversely, the equitability decreased, indicating a gradual decrease of the number of dominant species. Finally, the total abundance increased, coupled with rejuvenation and changes in size‐structure of the communities. Interestingly, most of these effects were not depressed by the strength of nonclimatic anthropogenic disturbances. Conversely, geographical location of communities and especially closeness of natural barriers to migration could influence their response to climate change. Indeed, increase in the proportion of southern species seemed hindered at sites located close to the southern limit of the European species' geographical ranges. This work provides new evidence that climate change have deep impacts on communities which, by overtaking the effects of nonclimatic anthropogenic disturbances, could be more substantial than previously thought. Overall, our results stress the importance of considering climate change impacts in studies addressing community dynamics, even in disturbed sites.
Energy feedbacks of northern high‐latitude ecosystems to the climate system due to reduced snow cover during 20th century warming
Authors: EUSKIRCHEN E. S. , McGUIRE A. D. , CHAPIN F. S. 
Published: October 2007

AbstractThe warming associated with changes in snow cover in northern high‐latitude terrestrial regions represents an important energy feedback to the climate system. Here, we simulate snow cover‐climate feedbacks (i.e. changes in snow cover on atmospheric heating) across the Pan‐arctic over two distinct warming periods during the 20th century, 1910–1940 and 1970–2000. We offer evidence that increases in snow cover–climate feedbacks during 1970–2000 were nearly three times larger than during 1910–1940 because the recent snow‐cover change occurred in spring, when radiation load is highest, rather than in autumn. Based on linear regression analysis, we also detected a greater sensitivity of snow cover–climate feedbacks to temperature trends during the more recent time period. Pan‐arctic vegetation types differed substantially in snow cover–climate feedbacks. Those with a high seasonal contrast in albedo, such as tundra, showed much larger changes in atmospheric heating than did those with a low seasonal contrast in albedo, such as forests, even if the changes in snow‐cover duration were similar across the vegetation types. These changes in energy exchange warrant careful consideration in studies of climate change, particularly with respect to associated shifts in vegetation between forests, grasslands, and tundra.
Use of the Interact Short Form as a tool to evaluate emotion of people with profound intellectual disabilities
Authors: Liu K. P. Y. , Lee T. , Yan A. , Siu C. W. M. , Choy F. W. Y. , Leung K. L. K. , Siu T. Y. , Kwan A. C. S. 
Published: October 2007

AbstractBackground  One of the essential purposes of intervention programmes for people with profound intellectual disabilities (ID) is to enhance the desirable mood and behaviour and decrease the undesirable ones through stabilizing their emotion. There is lack of validated instrument to offer a comprehensive measure that covers the mood and behaviour, both desirable and undesirable, appropriate for people with profound ID.Method  This study aimed to examine the validity and reliability of the Interact Short Form for evaluating the mood and behaviour of people with profound ID, and at the same time, review their emotional profile using the Interact Short Form. Both content validity using expert panel review and construct validity by means of factor analysis were investigated. A total of 75 people with profound ID were recruited. Inter‐rater reliability was tested. The results of the Interact Short Form were described to reflect the emotional profile of this group of participants.Results  Using the results of expert panel review and those from factor analysis, we found three subscales representing the mood and behaviour of people with profound ID. They were: ‘emotional expression’, ‘interests towards tasks’ and ‘behaviours to environment’. All three subscales were found to be internally consistent (α = 0.71–0.88). The Interact Short Form– People with profound ID version also showed good inter‐rater reliability (mean = 0.72). The results of the Interact Short Form showed that this group of participants had fairly stable emotion under the structured setting and activities in the residential institutions where data were collected.Conclusions  The Interact Short Form– People with profound ID version serves as a helpful tool for both clinical and research use in assessing the mood and behaviour of people with profound ID in a simple, comprehensive and systematic way.