bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of environmental factors on food intake and choice of beverage during meals in teenagers: a laboratory study
Authors: Péneau Sandrine , Mekhmoukh Amira , Chapelot Didier , Dalix Anne-Marie , Airinei Gheorghe , Hercberg Serge , Bellisle France
Published: August 2009

Environmental conditions influence meal size in adults and children. Intake of sweet drinks could contribute significantly to energy intake and potentially affect body weight, particularly in young individuals. The objectives of the present study were to measure the lunch intake of food and drinks under controlled laboratory settings in teenagers and to compare the influence of different meal conditions. Normal-weight adolescents (fourteen males and fifteen females) participated in four standardised lunches, scheduled 1 week apart. The same popular items (meat dish, dessert, water, juice, soda) were served at all meals.Ad libitumintake was measured under four conditions: subjects ate alone; in groups; alone while viewing television; alone while listening to music. Visual analogue scales were used to assess pre- and post-meal hunger and thirst and meal palatability. Energy, solid food and fluid intake was different (significantly lower) only in the ‘eating in group’ condition, in spite of identical intensity of pre-meal hunger. More soda was consumed when participants were watching television, and more water was consumed while listening to music. Across all conditions, more soda than water was consumed. Post-meal ratings of hunger, thirst and palatability did not differ between conditions. We concluded that, in teenagers, a ‘social inhibition’ effect appears rather than the ‘social facilitation’ previously reported in adults. Although teenagers do not respond to the presence of television or another ‘distractor’ such as music by eating more, they do ingest more soda when the television is on. The social significance of meals, conditioned responses and habituation to ‘distractors’ may be different between adolescents and adults.
Relationship between animal protein intake and muscle mass index in healthy women
Authors: Aubertin-Leheudre Mylène , Adlercreutz Herman
Published: August 2009

The amount and the type of dietary protein could play a role in determining the quantity of skeletal muscle mass. The aim was to examine the relationship between the type of protein intake and the level of muscle mass in healthy omnivorous and vegetarian Caucasian women. The design of the present study was an observational and cross-sectional study. Twenty-one omnivores (Om) and nineteen vegetarians (Ve) were recruited. Muscle mass index (urinary creatinine), dietary intake (5 d dietary records) and biochemical analyses (hormone, phyto-oestrogen and lipid profiles) were obtained. We found differences between groups for muscle mass (Ve: 18 kgv.Om: 23 kg;P = 0·010), muscle mass index (Ve: 6·7 kg/m2v.Om: 8·3 kg/m2;P = 0·002), animal protein intake in g/d (P = 0·001) and in g/kg body weight per d (P = 0·003), plant protein intake in g/d (P = 0·015) and in g/kg body weight per d (P = 0·007), the animal:plant protein intake ratio (P = 0·001) and sex hormone-binding globulin (SHBG) (P = 0·001). Muscle mass index still correlated with animal protein intake in g/d (P = 0·001) and in g/kg body weight per d (P = 0·008), and the animal:plant protein intake ratio (P = 0·007) even after controlling for SHBG and plant protein intake. Finally, animal protein intake (g/d) was the independent predictor of muscle mass index (adjustedr20·42). Thus, a vegetarian diet is associated with a lower muscle mass index than is an omnivorous diet at the same protein intake. A good indicator of muscle mass index in women seems to be animal protein intake.
FONIO MILLET (DIGITARIA EXILIS) RESPONSE TO N, P AND K FERTILIZERS UNDER VARYING CLIMATIC CONDITIONS IN WEST AFRICA
Authors: GIGOU J. , STILMANT D. , DIALLO T. A. , CISSÉ N. , SANOGO M. D. , VAKSMANN M. , DUPUIS B.
Published: August 2009

Fonio millet (Digitaria exilis), a small-grained cereal, plays an important role in food security in West Africa. As part of efforts to increase its productivity, we studied the effects of moderate levels of nitrogen (0, 15.0 and 30.0 kg N ha−1), phosphorus (0, 6.6 and 13.2 kg P ha−1) and potash (0, 12.5 and 25.0 kg K ha−1) fertilizers under varying climatic conditions. The three experimental sites at Bareng and Bordo in Guinea, and Cinzana in Mali, are representative of the distribution of fonio millet in West Africa. The average recorded grain yields were 1.51 ± 0.229, 1.08 ± 0.141 and 0.47 ± 0.182 t ha−1 in Bareng, Bordo and Cinzana, respectively. We observed a marginal to significant impact of N fertilization coupled, in Bordo, with a significant interaction with the P and K response. This interaction was highlighted by the limited effect of N without P or K fertilization or with the application of only one of these two major elements. Overall, N application as low as 15 kg ha−1 led to a 12–22% increase in production if the P and K applications were not limited. For better control over the risks associated with poor soil fertility and limited rainfall, it appeared to be more effective to apply moderate levels of N, P and K fertilizers to the fonio millet crop than a large amount of one of these nutrients.
Palaeoenvironmental reconstruction of the Sarmatian (Middle Miocene) Central Paratethys based on palaeontological and geochemical analyses of foraminifera, ostracods, gastropods and rodents
Authors: TÓTH EMŐKE , GÖRÖG ÁGNES , LÉCUYER CHRISTOPHE , MOISSETTE PIERRE , BALTER VINCENT , MONOSTORI MIKLÓS
Published: August 2009

Palaeoenvironmental changes in the upper Middle Miocene Central Paratethys were reconstructed by using qualitative and quantitative palaeontological analyses of foraminifera and ostracods, coupled with trace elemental (Mg/Ca) and stable isotope (δ18O and δ13C) analyses of their carbonate skeletons and of gastropod shells. Mean annual air temperatures were estimated using the oxygen isotope composition of contemporaneous rodent teeth. The studied aquatic fossils come from two boreholes in the Zsámbék Basin (northern central Hungary), while the terrestrial ones are from localities in NE Hungary and E Romania. In the studied Sarmatian successions, three zones could be distinguished, based on palaeontological and geochemical results. At the Badenian/Sarmatian boundary, faunal diversity decreased markedly. In the lower zone a transgressive event culminated in a seawater incursion into the semi-open basin system of the Central Paratethys. Stable bottom-water temperature (~15 °C) and variable salinities (20–32 ‰) are estimated for the Early Sarmatian Sea. The faunal changes (notably a strong reduction in biodiversity) occurring at the boundary between the lower and the middle zone can be explained by a sea-level highstand with dysoxic conditions. A relative sea-level fall is documented at the end of this middle zone. After a short regressive event, a marine connection between the Paratethys and the Mediterranean was established at the beginning of the upper zone. This is indicated by an increased microfaunal diversity and the re-appearance of marine Badenian ostracods and foraminifera, which are completely absent from the older Sarmatian series. During the upper zone, the temperatures and salinities are estimated to have fluctuated from 15 °C to 21 °C and from 15 ‰ to 43 ‰, respectively.
The genus Boccardia (Polychaeta: Spionidae) associated with mollusc shells on the south coast of South Africa
Authors: Simon C.A. , Worsfold T.M. , Lange L. , Sterley J.
Published: August 2009

Three species of Boccardia (B. polybranchia, B. pseudonatrix and B. proboscidea) were associated with mollusc shells on the south and south-east coasts of South Africa. Boccardia polybranchia was widely distributed along the coast and falls within the known distribution range of this species. Comparisons with material from other, international, locations showed that some specimens have been misidentified. No characters could be found to characterize distinct species for different regions within the range of B. polybranchia, as currently recognized. Boccardia pseudonatrix was found only at the most eastern site, increasing its known distribution range. Boccardia proboscidea, a non-indigenous species, was found only on abalone farms and was most abundant in the west.
Three new species of remosiid siphonophore (Siphonophora: Physonectae)
Authors: Pugh P.R. , Haddock S.H.D.
Published: August 2009

Three new species belonging to the family Resomiidae (Siphonophora: Physonectae) are described from material mainly collected by ROVs in the vicinity of Monterey Bay, California, USA, with some additional submersible-collected specimens from The Bahamas. Although these species,Resomia ornicephala,R. persica, andR. dunni, show some differences from those previously described, particularly in the shape of the nectophores, they have all been placed in the genusResomia. They retain the basic characteristic of having two forms of tentilla on the same tentacle, the more proximal form, with a spirally coiled cnidoband, becoming reconfigured into the more distal form, usually with a zigzagged cnidoband, although in one of the new species the zigzagging of the cnidoband is less well-defined.
Recognising and supporting self in dementia: a new way to facilitate a person-centred approach to dementia care
Authors: KELLY FIONA
Published: August 2009

This paper reports findings from a three-year study which integrated Kitwood's (1997) person-centred and Sabat's (2001) selfhood approaches in the design, fieldwork and analysis of a multi-method observational study that explored the social worlds of 14 people with dementia in continuing-care. The types of interactions that participants experienced in everyday ward life and during creative sessions were identified by observing, video-recording and engaging with them and by Dementia Care Mapping. The participants' responses to such interactions in terms of their well- or ill-being and expressions of self were identified and documented. The findings indicate that in the wards, staff interactions were often limited and sometimes abusive and that participants experienced ill-being, whereas during creative sessions, interactions were generally facilitatory and celebratory with the participants experiencing wellbeing. By developing the selfhood approach and integrating it with the person-centred approach, I argue that recognising and supporting selfhood (or not) during interactions can lead to qualitatively different staff behaviours, with consequences for the well- or ill-being of people with dementia. There is scope for incorporating this developed selfhood framework into staff training, for it has the potential to transform practice and the experiences of people with dementia in receipt of care.
Older people's needs following major disasters: a qualitative study of Iranian elders' experiences of the Bam earthquake
Authors: ARDALAN ALI , MAZAHERI MONIR , NAIENI KOUROSH HOLAKOUIE , REZAIE MOHSEN , TEIMOORI FARIBA , POURMALEK FARSHAD
Published: August 2009

Elders have long been recognised as among the most vulnerable people in disaster events. This paper reports a qualitative study of the self-perceived needs of older people in the aftermath of the Bam earthquake in Iran in 2003. A total of 56 people aged from 65 to 88 years were recruited to the study using purposive sampling, including 29 men and 27 women. Six focus group discussions and ten semi-structured individual interviews were conducted. Each focus group involved six to ten people from the cities of Bam and Baravat and their rural suburbs. Content analysis was used to analyse the transcribed data. The analysis identified four major themes among the informants' concerns: inappropriate service delivery, affronts to dignity, feeling insecure and emotional distress. A disaster-prone country like Iran needs to be appropriately prepared with culturally sensitive plans to meet the needs of those who suffer from their effects, not least older people. Emergency relief managers should note that for many older people in a disaster zone, customary forms of relief are neither required nor appropriate, and that their distinctive immediate and long-term needs should be assessed and met. Relief agencies need to be trained to be age-sensitive and should mainstream older people's rights in the planning and implementation of both the response and recovery phases of assistance.
The impact of sheep breed on the risk of classical scrapie
Authors: McINTYRE K. M. , TREWBY H. , GUBBINS S. , BAYLIS M.
Published: August 2009

The risk of classical scrapie in sheep is associated with polymorphisms in the prion protein (PrP) gene. In recent years, large-scale selective breeding programmes for sheep at lower risk of disease have been undertaken across the European Union. We analysed large-scale datasets on scrapie and sheep demography to investigate additional effects of sheep breed on scrapie risk. There was evidence for variation between certain breeds in the scrapie risk of some PrP genotypes, which could be caused by innate breed differences or distinct scrapie strains circulating within them. While the PrP genotypes of cases are generally consistent across breeds, some exceptions provide evidence that scrapie strain may influence affected PrP genotypes to a greater extent than innate breed differences. There was a significant association between the breed-level incidence of scrapie and the frequency of susceptible PrP genotypes in breeds. Our results lend support to selective breeding programmes which aim to reduce the frequency of high-risk PrP genotypes with measures not varying by sheep breed.
El Tor cholera with severe disease: a new threat to Asia and beyond
Authors: SIDDIQUE A. K. , NAIR G. B. , ALAM M. , SACK D. A. , HUQ A. , NIZAM A. , LONGINI I. M. , QADRI F. , FARUQUE S. M. , COLWELL R. R. , AHMED S. , IQBAL A. , BHUIYAN N. A. , SACK R. B.
Published: August 2009

During epidemics of cholera in two rural sites (Bakerganj and Mathbaria), a much higher proportion of patients came for treatment with severe dehydration than was seen in previous years. V. cholerae O1 isolated from these patients was found to be El Tor in its phenotype, but its cholera toxin (CT) was determined to be that of classical biotype. Whether the observed higher proportion of severe dehydration produced by the El Tor biotype was due to a shift from El Tor to classical CT or due to other factors is not clear. However, if cholera due to strains with increased severity spread to other areas where treatment facilities are limited, there are likely to be many more cholera deaths.
The CIFF proof procedure for abductive logic programming with constraints: Theory, implementation and experiments
Authors: MANCARELLA PAOLO , TERRENI GIACOMO , SADRI FARIBA , TONI FRANCESCA , ENDRISS ULLE
Published: August 2009

We present the CIFF proof procedure for abductive logic programming with constraints, and we prove its correctness. CIFF is an extension of the IFF proof procedure for abductive logic programming, relaxing the original restrictions over variable quantification (allowedness conditions) and incorporating a constraint solver to deal with numerical constraints as in constraint logic programming. Finally, we describe the CIFF system, comparing it with state-of-the-art abductive systems and answer set solvers and showing how to use it to program some applications.
ThepCO2dynamics in lakes in the boreal region of northern Québec, Canada
Authors: Roehm Charlotte L. , Prairie Yves T. , del Giorgio Paul A.
Published: August 2009

In this study, we examine the magnitude and temporal variability of surface waterpCO2in a set of lakes in boreal Québec, and explore the links between lake and catchment properties. The study lakes were consistently supersaturated in CO2, with the mean lakepCO2ranging from 400 to over 1800μatm. There was significant interannual variability inpCO2, apparently driven by regional patterns in precipitation. The best multivariate model of averagepCO2included dissolved organic carbon (DOC), lake area and chlorophyll as independent variables, suggesting that external carbon (C) loading to lakes plays a central role in lake CO2dynamics and that lake trophic status may modulate the influence of external C loading. We show that even if the key drivers of lakepCO2are similar, they interact differently among regions and the resulting models may be dramatically different. In particular, we show that althoughpCO2is invariably correlated to DOC, the shape of this relationship varies greatly among regions, suggesting large‐scale regional differences in C delivery, quality, and in‐lake processing. As a consequence, current models cannot be extrapolated across regions unless we apply region‐specific variables.
Heavy pollution suppresses light rain in China: Observations and modeling
Authors: Qian Yun , Gong Daoyi , Fan Jiwen , Leung L. Ruby , Bennartz Ralf , Chen Deliang , Wang Weiguo
Published: August 2009

Long‐term observational data reveal that both the frequency and amount of light rain have decreased in eastern China (EC) for 1956–2005 with high spatial coherency. This is different from the trend of total rainfall observed in EC, which decreases in northern EC and increases in southern EC. To examine the cause of the light rain trends, we analyzed the long‐term variability of atmospheric water vapor and its correlation with light rain events. Results show very weak relationships between large‐scale moisture transport and light rain in EC. Because of human activities, pollutant emission has increased dramatically in China for the last few decades, leading to a significant reduction in visibility between 1960 and 2000. Cloud‐resolving model simulations over EC show that aerosols corresponding to polluted conditions can significantly increase the cloud droplet number concentration (CDNC) and reduce droplet sizes compared to pristine conditions. This can lead to a significant decline in raindrop concentration and delay raindrop formation because smaller cloud droplets are less efficient in the collision and coalescence processes. Together with weaker convection, the precipitation frequency and amount are significantly reduced in the polluted case in EC. Satellite data also reveal higher CDNC and smaller droplet size over polluted land in EC relative to pristine regions, which is consistent with the model results. Observational evidences and simulations results suggest that the significantly increased aerosol concentrations produced by air pollution are at least partly responsible for the decreased light rain events observed in China over the past 50 years.
Flow and mixing dynamics in a patterned wetland: Kilometer‐scale tracer releases in the Everglades
Authors: Variano Evan A. , Ho David T. , Engel Victor C. , Schmieder Paul J. , Reid Matthew C.
Published: August 2009

Surface water flow dynamics in the Florida Everglades were investigated using sulfur hexafluoride tracer releases, from which advection and dispersion were determined. Several sites were studied, each characterized by different vegetation patterns and proximity to hydrologic control structures. The measured flow directions suggest that basin‐scale forcing from water management structures and operations can override the effects of local landscape features in guiding the flow. Management effects were particularly evident in two regions where the historic, natural landscape patterning has degraded. The large spatial scale over which tracer data were collected allows the dispersion rate to be determined at unprecedented spatial scales. These measurements showed much larger dispersion coefficients than reported by previous experiments at smaller scales. This finding and a measurement of the drag due to vegetation over large scales are of interest to Everglades water resource managers concerned with the transport of sediment and biologically active solutes such as phosphorous.
Leaching systematics and matrix elimination for the determination of high‐precision Pb isotope compositions of ocean island basalts
Authors: Nobre Silva Inês Garcia , Weis Dominique , Barling Jane , Scoates James S.
Published: August 2009

Ocean island basalts from Hawaii and Kerguelen were analyzed for their Pb isotopic compositions to assess the effect of acid leaching and matrix elimination by Pb anion exchange columns on reproducibility and accuracy. Unleached samples consistently yield Pb isotopic ratios that reflect the incorporation of foreign material. Leaching removes up to 70–80% of the total Pb content of the samples with corresponding weight losses between 35 and 60%. The older and more altered Kerguelen basalts show better external reproducibility than the Hawaiian basalts, which appears to be due to the presence in the Hawaiian samples of more radiogenic contaminants (e.g., seawater Pb, drilling mud, and related alteration phases). All leached samples purified twice on anion exchange columns show more radiogenic Pb isotopic ratios than those processed once. The difference is larger for tholeiitic basalts (Hawaiian and Kerguelen Plateau) than for transitional to alkalic basalts (Kerguelen Archipelago). The small differences in measured ratios of total procedural triplicates reflect differential elimination of residual alteration via leaching and matrix effects. The effectiveness of matrix elimination depends on the specific basalt composition, and tholeiitic basalts (i.e., low Pb concentrations) require two passes on anion exchange columns. This study shows that all steps in sample processing are critical for achieving accurate high‐precision Pb isotopic compositions of ocean island basalts.
O2(a1Δg, υ = 0) chemical loss coefficients determined from SABER sunset measurements
Authors: Nair Hari , Yee Jeng‐Hwa
Published: August 2009

Retrievals of mesospheric O3 using the 1.27 μm emission of O2(a1Δg, υ = 0) are critically dependent on the O2(1Δg) loss rate, which remains an uncertain parameter. We have analyzed the loss of O2(1Δg) after sunset using measurements of its 1.27 μm emission by the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) experiment aboard the Thermosphere Ionosphere Mesosphere Energetics and Dynamics (TIMED) spacecraft. The observed loss rates in the 70 to 90 km altitude region were fit using the Einstein A‐Coefficient at 1.27 μm and O2 collisional quenching rate coefficient as parameters. Our results agree well with currently accepted values, and confirm the only existing laboratory measurement of the quenching rate coefficient at mesospheric temperatures.
Ratio of coccolith CaCO3 to foraminifera CaCO3 in late Holocene deep sea sediments
Authors: Broecker Wallace , Clark Elizabeth
Published: August 2009

On the basis of measurements of the relative amounts of CaCO3 in the less than 20‐μm and the greater than 20‐μm size fractions in open ocean core tops, we find that the coccoliths contribute about half the calcite present in late Holocene deep sea sediments which have experienced little or no dissolution. Although this ratio is of importance to the understanding of the ocean's CaCO3 cycle, we can find only a few quantitative estimates of their relative contribution to currently forming marine sediments. As dissolution of foraminifera calcite takes place more rapidly than that of coccolith calcite, coccoliths dominate the CaCO3 in sediments which have experienced sizable dissolution. Although coccoliths contribute 40–60 of the CaCO3 in tropical sediments, higher‐latitude sediments and those adjacent to continental margins often have larger proportions of coccolith CaCO3.
On neutral metacommunity patterns of river basins at different scales of aggregation
Authors: Convertino Matteo , Muneepeerakul Rachata , Azaele Sandro , Bertuzzo Enrico , Rinaldo Andrea , Rodriguez‐Iturbe Ignacio
Published: August 2009

Neutral metacommunity models for spatial biodiversity patterns are implemented on river networks acting as ecological corridors at different resolution. Coarse‐graining elevation fields (under the constraint of preserving the basin mean elevation) produce a set of reconfigured drainage networks. The hydrologic assumption made implies uniform runoff production such that each link has the same habitat capacity. Despite the universal scaling properties shown by river basins regardless of size, climate, vegetation, or exposed lithology, we find that species richness at local and regional scales exhibits resolution‐dependent behavior. In addition, we investigate species‐area relationships and rank‐abundance patterns. The slopes of the species‐area relationships, which are consistent over coarse‐graining resolutions, match those found in real landscapes in the case of long‐distance dispersal. The rank‐abundance patterns are independent of the resolution over a broad range of dispersal length. Our results confirm that strong interactions occur between network structure and the dispersal of species and that under the assumption of neutral dynamics, these interactions produce resolution‐dependent biodiversity patterns that diverge from expectations following from universal geomorphic scaling laws. Both in theoretical and in applied ecology studying how patterns change in resolution is relevant for understanding how ecological dynamics work in fragmented landscape and for sampling and biodiversity management campaigns, especially in consideration of climate change.
Induction of RNA‐directed DNA methylation upon decondensation of constitutive heterochromatin
Authors: Schoft Vera K , Chumak Nina , Mosiolek Magdalena , Slusarz Lucyna , Komnenovic Vukoslav , Brownfield Lynette , Twell David , Kakutani Tetsuji , Tamaru Hisashi
Published: August 2009

Centromeric constitutive heterochromatin is marked by DNA methylation and dimethylated histone H3 Lys 9 (H3K9me2) in Arabidopsis. RNA‐directed DNA methylation (RdDM) is a process that uses 24‐nucleotide (nt) small interfering RNAs (siRNAs) to induce de novo methylation to its homologous DNA sequences. Despite the presence of centromeric 24‐nt siRNAs, mutations in genes required for RdDM do not appreciably influence the methylation of centromeric repeats. The mechanism by which constitutive heterochromatin is protected from RdDM remains puzzling. Here, we report that the vegetative cell nuclei (VN) of the male gametophyte (pollen) invariably undergo extensive decondensation of centromeric heterochromatin and lose centromere identity. VN show greatly reduced H3K9me2, phenocopying nuclei carrying a mutation in the chromatin remodeller DECREASE IN DNA METHYLATION 1 (DDM1). However, unlike the situation in ddm1 nuclei, the decondensed heterochromatin retains dense CG methylation and transcriptional silencing, and, unexpectedly, is subjected to RdDM‐dependent hypermethylation in non‐CG contexts. These findings reveal two assembly orders of silent heterochromatin and implicate the condensed form in blocking the RdDM machinery.
Bub1 and Bub3 promote the conversion from monopolar to bipolar chromosome attachment independently of shugoshin
Authors: Windecker Hanna , Langegger Maria , Heinrich Stephanie , Hauf Silke
Published: August 2009

The eukaryotic spindle assembly checkpoint (SAC) delays anaphase in the presence of chromosome attachment errors. Bub3 has been reported to be required for SAC activity in all eukaryotes examined so far. We find that Bub3, unlike its binding partner Bub1, is not essential for the SAC in fission yeast. As Bub3 is needed for the efficient kinetochore localization of Bub1, and of Mad1, Mad2 and Mad3, this implies that most SAC proteins do not need to be enriched at the kinetochores for the SAC to function. We find that Bub3 is also dispensable for shugoshin localization to the centromeres, which is the second known function of Bub1. Instead, Bub3, together with Bub1, has a specific function in promoting the conversion from chromosome mono‐orientation to bi‐orientation.
Coexistence by recruitment variation: How large is the contribution of relative nonlinearity?
Authors: Yuan Chi , Chesson Peter
Published: August 2009

*Background/Question/Methods*

Recruitment variation is believed to be an important mechanism of species coexistence in variable environments. This mechanism, however, is a composite of two other mechanisms: the storage effect, and relative nonlinearity. The storage effect is a formalization of the concept of temporal environmental niche differentiation. It is well-understood theoretically and has been tested in natural systems such as forests and annual plant communities. Relative nonlinearity results from species differences in nonlinear responses to fluctuations in competition. Such differences arise whenever species differ in life-history traits such as mean longevity. While the storage effect is assumed to be the stronger mechanism, no studies have compared the relative magnitudes of the storage effect and relative nonlinearity in the same system, and so there has been no rigorous justification for the neglect of relative nonlinearity in theoretical and empirical studies of coexistence by recruitment variation. Our research uses analytical modeling and simulation tools to quantify the magnitude of these two mechanisms for iteroparous organisms coexisting by recruitment variation.

*Results/Conclusions*

Our results show that the strength of relative nonlinearity increases with species differences in longevity, and is larger with larger environmental variation. However, the storage effect is also larger with larger environmental variation, and in most cases, is much stronger than relative nonlinearity. Nevertheless, there are circumstances where relatively nonlinearity is predicted to be stronger than the storage effect. We find this is outcome in two-species cases where species have strong differences in their sensitivities to environmental fluctuations, as well as having different longevities. Indeed, it is possible for the storage effect to make no contribution to stabilization of coexistence, leaving relative nonlinearity as the only stabilizing mechanism. However, this outcome occurs only in a narrow range of circumstances. We conclude that under most circumstances, relative nonlinearity contributes little to the overall stabilizing effect and the neglect of relative nonlinearity in previous work is justified in those cases. Nevertheless, relative nonlinearity has the potential to make substantial contributions to species coexistence when species differ in their sensitivities to environmental variation.
The significance of ponds in maintaining biodiversity in an intensively farmed landscape
Authors: Gioria Margherita , Feehan John
Published: August 2009

*Background/Question/Methods*

Ponds are amongst the most diverse freshwater habitats and have been recently found to support more species, as well as more uncommon, rare, and threatened species compared to lakes, rivers, and streams. The conservation of ponds represents a cost-effective way of maintaining or enhancing biodiversity, because of the typical small size of pond catchment areas. Moreover, ponds may be effectively used as models systems because of their small size and large number compared to lakes. At present, there is an urgent need to collect data on the ecological quality of freshwater bodies to develop programmes aimed at meeting defined water quality targets by the year 2015, in fulfillment of obligations deriving from the European Water Framework Directive (Directive 2000/60/EC). In this study, we used ponds to make a rapid assessment of the ecological quality of an intensively farmed region in Ireland. Such an assessment was based on an investigation of the aquatic Coleoptera and wetland plant assemblages of 25 farmland ponds, in June and July 2008. The relationships between Coleoptera and wetland plants with 20 habitat characteristics and water chemistry variables were also investigated, in order to improve our understanding of the factors that are important in determining patterns in pond diversity. *Results/Discussion*Gamma diversity was high, with 63 aquatic Coleoptera species recorded between June and July 2008, although alpha diversity ranged widely (4-33, mean = 15). Overall, pond water quality was poor and high levels of nitrates and phosphates were recorded. However, patterns in pond diversity were complex and no single factor was determinant. PCA, MDS, BIOENV, and regression analyses showed that habitat variables such as pond size, habitat complexity, wetland plant richness (68 species, range: 1-26, mean = 13), permanency, and grazing intensity were more important than water chemistry variables in determining patterns in Coleoptera assemblages. Permanency, pond depth, conductivity, and dissolved oxygen were the variables that best explained patterns in the taxonomic composition of wetland plants. Overall, this study confirmed the importance of ponds in supporting biodiversity even within intensively farmed regions and where reference sites are not available. Aquatic Coleoptera proved to be a useful group for assessing the ecological quality of ponds. The results of this study are important to improve our understanding of the relationship between patterns of pond diversity and environmental variables, as well as to integrate existing large-scale datasets on pond diversity.
Individual and seasonal variation in the diet of the endangered Barton Springs Salamander (Eurycea sosorum): An application of stable isotope analysis to the conservation of an endangered species
Authors: Gillespie J. Hayley
Published: August 2009

It is well known that many species show strong temporal variation in diet. Long-term dietary trends may be important in assessing the effects of ecological change such as global warming, land use change, or introductions of invasive species. Short-term variation in food sources or prey selection may be crucial for understanding population dynamics in poorly understood species. The Barton Springs Salamander (Eurycea sosorum) is an endangered species endemic to four small spring outflows in downtown Austin, Texas. This species remains aquatic throughout life and inhabits benthic rocky substrate. While little is known about its foraging ecology, E. sosorum is assumed to be a generalist predator with the abundant amphipod Hyalella azteca as its primary food source. The salamander’s secretive behavior and obscure microhabitat make direct foraging observations impossible. Thus, stable isotope applications may be the only feasible means of estimating diet in these animals. Measurements of [delta]^13^C and [delta]^15^N for wild-caught Eurycea sosorum and a suite of potential invertebrate prey (amphipods, chironomids and planarians) were taken in November 2007, February 2008, May 2008 and August 2008. Quantitative invertebrate censuses track seasonal changes in invertebrate relative abundance. A multi-source mixing model is applied to field isotope data, and a distribution of likely prey item contributions to salamander diet is obtained for each season. Measurement of [delta]^13^C and [delta]^15^N from captive-bred E. sosorum raised on a constant diet indicate minimal fractionation of [delta]^13^C (<1‰) and approximately 2.3‰ enrichment in [delta]^15^N per trophic level. Mixing model results show that salamanders feed nearly equally on planarians (53-57% of diet) and amphipods (43-47% of diet) during the course of the study, and that chironomids do not contribute to the diet of E. sororum. The relative isotopic relationship between the three prey items and salamander tissue remains constant over the course of the study. Furthermore, individual variation in salamander diet is large in all seasons (range of 6-8‰ of [delta]^13^C values for individual salamanders), potentially reflecting the highly clumped prey item distributions or individual specialization on different food resources.Stable isotope techniques allow investigation of how diet composition responds to temporal changes in prey availability in field populations and the degree to which intrapopulation diet variation influences overall population diet estimates. This work provides conservation biologists at Barton Springs with essential information on the diet and ecology of E. sosorum, which is being used to improve species management plans that will be applicable to other spring systems.
Urban Ecosystems: Alterations to Peakflow, Microclimate and the Natural Environment
Authors: Hubbart Jason
Published: August 2009

More than half of the world’s population now lives in urbanized ecosystems. Continued human population growth over the next several decades will place unprecedented demand on urban water resources, resulting in escalating water quality and supply challenges. Urbanization exacts significant impacts on stream ecosystems including increased magnitude and frequency of peak flows, altered microclimates and reduced biodiversity. Increased impervious surface area in urban settings reduces or eliminates soil infiltration and increases the amount of stormwater runoff delivered to stream channels. Stormwater routing networks in urban areas channelize runoff, reducing stormwater transit time. Stormwater flow serves as an important transport mechanism for non-point source pollutants, and impervious surfaces serve as conduits to flow, replacing soils and vegetation that would otherwise attenuate runoff and transport of pollutants. Stream channels typically broaden and deepen in response to increased volume, velocity and frequency of peak flows, leading to increased channel instability, accelerated erosion, and subsequent loss of habitat. Given these scenarios, urbanization can degrade freshwater resources, detrimentally impact in-stream and riparian biota, and destroy riparian wetland form and function. The following work quantifies peak flow and microclimate alteration due to urbanization in a large, multi-use watershed of the central U.S. A long-term stream flow monitoring program was established in the Hinkson Creek Watershed located in Boone County, mid-Missouri during the fall of 2008. Hydroclimate stations were installed at five locations along Hinkson Creek within predominantly forest, cropland, and urban environments. Continuous stream stage and flow data from these sites were used to quantify peak flow in different environments of the watershed. Preliminary results indicate that forested environments tend to attenuate peak flows from small precipitation events (< 0.80 mm), whereas events of similar magnitude in urban settings cause spikes in flow and a flashier hydrograph. With larger precipitation events (> 1.0 mm), the time from peak rainfall to peak flow is decreased by as much as 13% in urban settings accompanied by at least 4 cm higher peak flows and 15-20% greater flow volume. Average air temperatures in the urban region exceed the forested region by at least 15% during winter months, holding important implications for snow melt and runoff, peak flow and ecosystem processes. Continued monitoring and analyses will more precisely quantify the effects of urbanization on these phenomena and will provide critical information for the sustainable management of urban natural resources.
Using SeaWiFS and In Situ Data for HAB Prediction in the Northern Gulf of Mexico: Decision Tree Analysis
Authors: Holiday Dan , Carter Greg
Published: August 2009

To date, 13 potential HAB species have been detected in coastal waters of Mississippi and Alabama, including representatives of the diatom genera Pseudo-nitzschia and Chaetoceros, and dinoflagellate genera Karenia, Gonyaulax, Akashiwo, Karlodinium, and Prorocentrum. This study investigates the potential of satellite remote sensing (SeaWiFS) to predict environmental conditions leading to the formation of HABs in these turbid coastal waters. Phytoplankton populations and water quality were monitored in situ at 3 to 6 week intervals and 17 locations in Mobile Bay and the Mississippi Sound from December, 2004, through June, 2006. SeaWiFS imagery corresponding with in situ collections was acquired. Non-parametric multivariate analyses determined relationships between phytoplankton cell counts and in situ or satellite-derived water properties, including surface temperature, salinity, concentrations of chlorophyll, total suspended solids, colored dissolved organic material, and nutrient levels. This paper will describe an expert system decision tree analysis approach to prediction of ecological conditions necessary for the formation of HABs. The model assumes unique ranges of remote sensing reflectance ratios, Chl a, and total suspended solids must exist within the environment are conducive for the formation of HABs.
Use of single-molecule spectroscopy to tackle fundamental problems in biochemistry: using studies on purple bacterial antenna complexes as an example
Authors: Cogdell Richard J. , Köhler Jürgen
Published: August 2009

Optical single-molecule techniques can be used in two modes to investigate fundamental questions in biochemistry, namely single-molecule detection and single-molecule spectroscopy. This review provides an overview of how single-molecule spectroscopy can be used to gain detailed information on the electronic structure of purple bacterial antenna complexes and to draw conclusions about the underlying physical structure. This information can be used to understand the energy-transfer reactions that are responsible for the earliest reactions in photosynthesis.
Synthesis and Properties of Novel 'Ethyne-linked' Compounds Containing Carbazole and 1, 8-naphthalimide Groups
Authors: Liu Yu , Wang Hai-Ying , Chen Gang , Xu Xiao-Ping , Ji Shun-Jun
Published: August 2009

A series of the novel ‘ethyne-linked’ compounds containing carbazole and 1,8-naphthalimide groups have been synthesized by Pd/Cu-catalyzed Sonogashira reaction. These compounds were fully characterized by means of Fourier-transform IR, 1H, 13C NMR, and high resolution mass spectroscopy. The thermal, optical, and electrochemical properties were also investigated. As we expected, the results indicated that these compounds could improve charge-transport ability and fluorescent quantum yield by introducing the electron-transporting emitting moieties naphthalimide and the alkyne group to carbazole moieties.
Poly(ethylene glycol): an Alternative Solvent for the Synthesis of Cyclic Carbonate from Vicinal Halohydrin and Carbon Dioxide
Authors: Wang Jing-Lun , He Liang-Nian , Dou Xiao-Yong , Wu Fang
Published: August 2009

Poly(ethylene glycol) (PEG) in this work proved to be an efficient reaction medium for the reaction of vicinal halohydrin with carbon dioxide in the presence of a base to synthesise cyclic carbonates. Notably, PEG-400 as an environmentally friendly solvent exhibits a unique influence on reactivity compared with conventional organic solvents. Various cyclic carbonates were prepared in high yield employing this protocol. The process presented here has potential applications in the industrial production of cyclic carbonates because of its simplicity, cost benefits, ready availability of starting materials, and mild reaction conditions.
Termination in Semi-Dilute and Concentrated Polymer Solutions
Authors: Johnston-Hall Geoffrey , Monteiro Michael J.
Published: August 2009

The aim of the present work was to develop a deeper understanding into termination processes in the semi-dilute and concentrated regimes. The study was carried out to examine the effect of termination between linear polystyrene radical chains in linear, four-arm star, and six-arm star polymer systems using the reversible addition–fragmentation chain transfer chain length-dependent termination method. In particular, the power-law dependencies of both chain length and polymer concentration were evaluated in the semi-dilute and concentrated regimes. We found that theoretical predictions based on the blob model were in good agreement with the experimentally observed evolution of the rate coefficient for biomolecular termination, kti,i(x), in the semi-dilute solution regime. In addition, solvent quality was found to decrease with increasing chain length, increasing polymer concentration and as a function of the matrix topology (i.e. for star polymer solutions). In the concentrated solution regime, the role of chain entanglements became evident by determining the conversion-dependent power-law exponent, βgel (where kt ≈ x–βgel), which increased in the order: linear < four-arm star < six-arm star polymer systems. Above the critical chain length ic, termination was found to be primarily conversion-dependent, implying entanglements dominated termination between linear polymeric radicals. Although this may suggest that reptation plays an important role, our data are in disagreement with this theory, suggesting that the polymer matrix cannot be regarded as static or immobile on the diffusion time scales for bimolecular termination.
Polydimethylsiloxane-Based Polyurethanes: Phase-Separated Morphology and In Vitro Oxidative Biostability
Authors: Choi Taeyi , Weksler Jadwiga , Padsalgikar Ajay , Hernéndez Rebeca , Runt James
Published: August 2009

Three series of segmented polyurethane block copolymers were synthesized using 4,4′-methylenediphenyl diisocyanate (MDI) and 1,4-butanediol (BDO) or 1,3-bis(4-hydroxybutyl)tetramethyl disiloxane (BHTD) as the hard segments, and soft segments composed of poly(dimethyl siloxane) (PDMS)-based and poly(hexamethylene oxide) (PHMO) macrodiols. Copolymers synthesized with the PDMS macrodiol and PDMS and PHMO macrodiol mixtures consist of three microphases: a PDMS phase, hard domains, and a mixed phase of PHMO (when present), PDMS ether end-group segments and some dissolved hard segments. Degrees of phase separation were characterized using small-angle X-ray scattering by applying a pseudo two-phase model, and the morphology resulting from unlike segment demixing was found to be closely related to the in vitro oxidative biostability of these segmented polyurethanes.
Supramolecular BioNanocomposites: Grafting of Biobased Polylactide to Carbon Nanoparticle Surfaces
Authors: Sobkowicz Margaret J. , Dorgan John R. , Gneshin Keith W. , Herring Andrew M. , McKinnon J. Thomas
Published: August 2009

Novel carbon nanostructures are attracting increasing interest and the combination of graphitic substrates with grafted biodegradable polymers may ultimately be of interest in a variety of biomedical and sensing applications. Here, a novel graphitic nanosubstrate, carbon nanospheres derived from cellulose, is functionalized with polylactides (PLA) using an established thionyl chloride intermediate scheme; the resulting supramolecular bionanocomposite is 97% from renewable resources. In addition, a direct ‘grafting from’ approach is utilized to grow polylactide chains on multi-walled carbon nanotubes (MWCNT). In the latter case, unlike previous approaches, the ring-opening polymerization is initiated directly from a hydroxyl bearing surface. Verification of the covalent attachment and characterization of the grafted layer are accomplished via a variety of techniques and methods. Even after repeated washing, thermal gravimetric analysis clearly shows the presence of a grafted layer, which decomposes at approximately 300°C, a value characteristic of PLA; it is found that 20 mg m–2 of PLA is grafted to the MWCNT and 3.9 mg m–2 of PLA is grafted to the carbon nanospheres. Solubility tests clearly show the graphitic structures have been fundamentally altered in their physiochemical properties; they become highly soluble in chloroform after the grafting reaction is complete. Transmission electron microscopy provides evidence of a 2–3 nm thick polymer layer. Finally, Fourier transform infrared spectroscopy shows several characteristic peaks of PLA including the ester group at 1760 cm–1.