bluuebunny/crossref_metadata_2025_split huggingface dataset:
Body size determines the outcome of competition for webs among alien and native sheetweb spiders (Araneae: Linyphiidae)
Authors: EICHENBERGER BEATA , SIEGENTHALER EVA , SCHMIDT‐ENTLING MARTIN H. 
Published: March 2009

Abstract 1. Biotic invasions are one of the most important reasons for changes in biodiversity. The alien sheetweb spider Mermessus trilobatus (Araneae: Linyphiidae) has become abundant in large parts of Central Europe within the past three decades. Its invasion might negatively influence native spiders, for instance via competition for webs.2. Laboratory experiments were developed to test if M. trilobatus is competitively superior to native spiders. The alien M. trilobatus and five native sheetweb spiders (Erigone dentipalpis, E. atra, Gnathonarium dentatum, Dicymbium nigrum and Micrargus herbigradus) were compared with respect to their success to take over occupied webs from E. dentipalpis.3. The rate of web takeover or defence was determined by body size, whereby individuals with a wider thorax invaded webs more successfully. After taking body size into account, the frequency of defence or web takeover did not differ between species. In 13% of all confrontations, predation against generally smaller opponents was recorded. Contrary to the predictions, raising the web value with food resources did not raise the effort expended on web defence but reduced predation by the web owner.4. The current study does not indicate that the invasion of the relatively small‐sized M. trilobatus is facilitated by strong competitiveness. Nevertheless, M. trilobatus may displace smaller‐sized immature specimens and thereby threaten native spiders. Still, other reasons are likely to underlie the success of M. trilobatus in Europe, such as rapid reproduction or release from natural enemies.
The double cloak of invisibility: phenotypic plasticity and larval decoration in a geometrid moth,Synchlora frondaria, across three diet treatments
Authors: CANFIELD MICHAEL R. , CHANG SUE , PIERCE NAOMI E. 
Published: March 2009

Abstract1. Crypsis is one of the main defences that insects use to avoid predators, and both the juveniles and adults of many geometrid moths are remarkable in their ability to blend into different host backgrounds. The larvae ofSynchlora frondariahave two methods to achieve crypsis: phenotypic plasticity in colouration that enable them to hide more effectively on their host plants, and a self‐decorating behaviour whereby the larvae camouflage themselves with materials from their host plants.2. Larvae ofSynchlora frondariareared on three different host plants showed systematic differences in relative growth rate, survivorship and larval colouration.3. Larval colouration varied across diet treatments in a way that was consistent with diet‐induced phenotypic plasticity, and larvae also exhibited characteristic decorating behaviour on all three hosts.4. Larvae showed highest survivorship onHeterotheca subaxillaris(Asteraceae), and had significantly higher relative growth rates onH. subaxillaris(Asteraceae) andLantana camara(Verbenaceae) than onBejaria racemosa(Ericaceae).5. Synchlora frondariaprovides an example of a species where both decorating behaviour and phenotypic plasticity in larval colouration produce a cryptic form that is remarkably responsive to its background.
Extreme longevity in freshwater mussels revisited: sources of bias in age estimates derived from mark–recapture experiments
Authors: HAAG WENDELL R. 
Published: March 2009

Summary1. There may be bias associated with mark–recapture experiments used to estimate age and growth of freshwater mussels. Using subsets of a mark–recapture dataset for Quadrula pustulosa, I examined how age and growth parameter estimates are affected by (i) the range and skew of the data and (ii) growth reduction due to handling. I compared predictions from von Bertalanffy growth models based on mark–recapture data with direct observation of mussel age and growth inferred from validated shell rings.2. Growth models based on a dataset that included observations from a wide range of length classes (spanning ≥ the upper 50% of the population length range) produced only slightly biased age estimates for small and medium‐sized individuals (overestimated by 1–2 years relative to estimates from validated shell rings) but estimates became increasingly biased for larger individuals. Growth models using data that included only observations of larger animals (< the upper 50% of length range) overestimated age for all length classes, and estimated maximum age was two to six times greater than the maximum age observed in the population (47 years). Similarly, growth models using a left‐skewed dataset overestimated age.3. Reductions of growth due to repeated handling also resulted in overestimates of age. The estimated age of mussels that were handled in two consecutive years was as much as twice that of mussels that were handled only once over the same period. Assuming a constant reduction in the annual rate of growth, handling an individual for five consecutive years could result in an estimated age that is five times too high.4. These findings show that mark–recapture methods have serious limitations for estimating mussel age and growth. A previous paper (Freshwater Biology, 46, 2001, 1349) presented longevity estimates for three mussel species that were an order of magnitude higher than estimates inferred from shell rings. Because those estimates of extreme longevity were based on mark–recapture methods and subject to multiple, additive sources of bias, they cannot be considered accurate representations of life span and cannot be used to conclude that traditional methods of bivalve ageing by interpretation of shell rings are flawed.
Impact of the fish Garra on the ecology of reservoirs and the occurrence of Microcystis blooms in semi‐arid tropical highlands: an experimental assessment using enclosures
Authors: DEJENIE TADESSE , ASMELASH TSEHAYE , ROUSSEAUX SARAH , GEBREGIORGIS TEKLIT , GEBREKIDAN ABREHA , TEFERI MEKONEN , NYSSEN JAN , DECKERS JOZEF , VAN DER GUCHT KATLEEN , VYVERMAN WIM , DE MEESTER LUC , DECLERCK STEVEN A. J. 
Published: March 2009

Summary1. Many man‐made reservoirs in the semi‐arid highlands of Northern Ethiopia (Tigray) are characterised by the occurrence of intensive blooms of cyanobacteria and a dominance of small riverine fishes belonging to the genus Garra.2. We carried out enclosure experiments to test for the effect of these small fish on abiotic characteristics, phytoplankton biomass and zooplankton community structure in the pelagic of two reservoirs (Gereb Awso and Tsinkanet). Two experiments were carried out in each of the reservoirs, one at the end of the rainy season (highest water level) and one at the end of the dry season (lowest water level).3. The presence of Garra in general increased the amount of suspended matter, nutrient concentrations (total nitrogen and total phosphorus), phytoplankton and Microcystis biomass (including the proportion of Microcystis in the phytoplankton community), and reduced water transparency. The positive effect of the presence of Garra on nutrient concentrations and phytoplankton productivity indicate that Garra has the potential to affect food web functioning indirectly through bottom‐up effects, by enhancing nutrient concentrations through sediment resuspension and excretion of nutrients. Indeed, population densities of the cladoceran zooplankton taxa Ceriodaphnia and Diaphanosoma also showed an overall increase in enclosures with Garra.4. However, our data also provide some evidence for a potential of Garra to exert top‐down control on large bodied daphnids (Daphnia carinata, D. barbata), although such effect varied among experiments. The limited capability of Garra to control zooplankton communities mainly reflects the low efficiency of these small, riverine and benthos‐oriented fish in foraging on zooplankton and suggests the existence of an unoccupied niche for zooplanktivorous fish in the majority of the reservoirs.5. Although the main effects of Garra on the pelagic food web seemed to be mediated by bottom‐up mechanisms, our results also indicate that one of the key variables, the relative abundance of Microcystis, was impacted by Daphnia‐mediated trophic cascade effects.
Mortality of developing floodplain forests subjected to a drying climate and water extraction
Authors: HORNER GILLIS J. , BAKER PATRICK J. , MAC NALLY RALPH , CUNNINGHAM SHAUN C. , THOMSON JAMES R. , HAMILTON FIONA 
Published: March 2009

AbstractRiver regulation and water extraction have altered the hydrology of rivers resulting in substantial changes to forest structure and the dieback of floodplain forests globally. Forest mortality, due to water extraction, is likely to be exacerbated by climate change‐induced droughts. In 1965, a plantation trial was established within a natural floodplain forest to examine the effect of planting density on timber production. We used data from this trial to investigate the effect of initial stand density on the structure and dynamics of Eucalyptus camaldulensis (Dehnh.) forests. Highest density stands (8000 trees ha−1) were dominated by many slender trees, mostly<10 cm in diameter, whereas the lowest density stands produced size distributions with a wider range of stem diameters and higher mean and maximum stem diameter. After 1996, the study area experienced a sharp decline in water availability due to a substantial lowering of the water table, reduced flooding frequency, a pronounced rainfall deficit and increased maximum temperatures. The drought coincided with a dramatic increase in mortality in the high‐density stands, yet remained little changed in low‐density treatments. Our results highlight the importance of initial stand density as a key determinant of the development of forest structure. Early thinning of high‐density stands is one component of a broader management approach to mitigate impacts of human‐induced drought and water extraction on developing floodplain forests.
Relative impacts of disturbance and temperature: persistent changes in microenvironment and vegetation in retrogressive thaw slumps
Authors: LANTZ TREVOR C. , KOKELJ STEVEN V. , GERGEL SARAH E. , HENRY GREG H. R. 
Published: March 2009

AbstractIn the Low Arctic, a warming climate is increasing rates of permafrost degradation and altering vegetation. Disturbance associated with warming permafrost can change microclimate and expose areas of ion‐rich mineral substrate for colonization by plants. Consequently, the response of vegetation to warming air temperatures may differ significantly from disturbed to undisturbed tundra. Across a latitudinal air temperature gradient, we tested the hypothesis that the microenvironment in thaw slumps would be warmer and more nutrient rich than undisturbed tundra, resulting in altered plant community composition and increased green alder (Alnus viridis subsp. fruticosa) growth and reproduction. Our results show increased nutrient availability, soil pH, snow pack, ground temperatures, and active layer thickness in disturbed terrain and suggest that these variables are important drivers of plant community structure. We also found increased productivity, catkin production, and seed viability of green alder at disturbed sites. Altered community composition and enhancement of alder growth and reproduction show that disturbances exert a strong influence on deciduous shrubs that make slumps potential seed sources for undisturbed tundra. Overall, these results indicate that accelerated disturbance regimes have the potential to magnify the effects of warming temperature on vegetation. Consequently, understanding the relative effects of temperature and disturbance on Arctic plant communities is critical to predicting feedbacks between northern ecosystems and global climate change.
Identification and function of Abdominal‐A in the silkworm, Bombyx mori
Authors: Pan M‐H. , Wang X‐Y. , Chai C‐L. , Zhang C‐D. , Lu C. , Xiang Z‐H. 
Published: March 2009

Abstract Abdominal‐A (adb‐A) is a key gene in the development of insects. To understand its function in the silkworm, we cloned 1193 bp of the abd‐A gene of Bombyx mori (Bmabd‐A), including the complete coding sequence and part of the 3′ untranslated region sequence. Bmabd‐A has at least three mRNA splice variants with coding sequences of lengths 1032, 1044 and 1059 bp, encoding 343, 347 and 352 amino acids, respectively. Each splice variant of Bmabd‐A has three exons and differs only in second exon size. Bmabd‐A was expressed at low levels in unfertilized eggs, but increased gradually in fertilized eggs after laying 22 h. Bmabd‐A expression decreased in ant silkworms (newly hatched silkworms). After RNA interference for Bmabd‐A, the embryos had two mutant phenotypes, either completely or partially absent abdominal feet from the third to sixth abdominal segments, suggesting that Bmabd‐A is responsible for normal development of the third to sixth abdominal segments during embryonic development.
Transcriptome analysis of the salivary glands of the female tick Amblyomma americanum (Acari: Ixodidae)
Authors: Aljamali M. N. , Hern L. , Kupfer D. , Downard S. , So S. , Roe B. A. , Sauer J. R. , Essenberg R. C. 
Published: March 2009

AbstractTicks infest a wide range of hosts while bypassing their immune, inflammatory and haemostatic responses during their extended feeding, which may last for more than two weeks. Here, we present a transcriptome analysis of 3868 expressed sequence tags (ESTs) from three cDNA libraries generated from the salivary glands of adult female Ambyomma americanum ticks at different stages of feeding. We applied a normalization step for one library, significantly decreasing the abundance of mitochondrial sequences amongst the 2292 sequences from the normalized library. Our ESTs include homologues that may modulate haemostatic, immune and inflammatory responses of the hosts. Other ESTs probably represent important components of the highly efficient secretory pathways for salivary proteins and concomitantly transmitted pathogens.
A venom metalloproteinase from the parasitic wasp Eulophus pennicornis is toxic towards its host, tomato moth (Lacanobia oleracae)
Authors: Price D. R. G. , Bell H. A. , Hinchliffe G. , Fitches E. , Weaver R. , Gatehouse J. A. 
Published: March 2009

AbstractThree genes encoding clan MB metalloproteinases (EpMP1–3) were identified from venom glands of the ectoparasitic wasp Eulophus pennicornis. The derived amino acid sequences predict mature proteins of approximately 46 kDa, with a novel two‐domain structure comprising a C‐terminal reprolysin domain, and an N‐terminal domain of unknown function. EpMP3 expressed as a recombinant protein in Pichia pastoris had gelatinase activity, which was inhibited by EDTA. Injection of recombinant EpMP3 into fifth instar Lacanobia oleracea (host) larvae resulted in partial insect mortality associated with the moult to sixth instar, with surviving insects showing retarded development and growth. EpMP3 is expressed specifically in venom glands. These results suggest that EpMP3 is a functional component of Eulophus venom, which is able to manipulate host development.
Two hsp23 genes in the Mediterranean fruit fly, Ceratitis capitata: structural characterization, heat shock regulation and developmental expression
Authors: Kokolakis G. , Kritsidima M. , Tkachenko T. , Mintzas A. C. 
Published: March 2009

AbstractIn the present study, we characterized a 3320‐bp genomic DNA fragment encoding two medfly (Ceratitis capitata) homologues of the Drosophila melanogaster heat shock protein 23 (hsp23) gene, named Cchsp23‐αand ‐β. The two medfly hsp23 genes are transcribed in opposite directions and encode two almost identical proteins. Furthermore, the two genes exhibit a very high degree of similarity in their 5′ untranslated and proximal promoter regions. Phylogenetic analysis indicated that the CcHsp23 proteins are orthologous to Drosophila Hsp23 and Sarcophaga crassipalpis Hsp23. Structural analysis of the 5′ flanking regions of the Cchsp23 genes revealed the presence of several putative heat shock elements. Both CcHsp23 genes are induced by heat in a similar manner. In addition to heat‐induction, the Cchsp23 genes are expressed at several stages of normal development as well as in ovaries and testes. In general, the developmental expression patterns of the medfly genes are similar, suggesting that they are under similar regulatory mechanisms. However, the expression of the Cchsp23 genes differs significantly from the expression of the Drosophila hsp23 gene in certain embryonic and larval stages, suggesting differential regulation of the hsp23 genes in the two dipteran species. The expression of both Cchsp23 genes in adult flies is increased with age, especially in males.
Molecular characterization and expression of three heat shock protein70 genes from the carmine spider mite, Tetranychus cinnabarinus (Boisduval)
Authors: Li M. , Lu W. C. , Feng H. Z. , He L. 
Published: March 2009

AbstractThree heat shock protein 70 (Hsp70) cDNAs were isolated from the carmine spider mite, Tetranychus cinnabarinus. They were tentatively named as TCHsp70‐1, TCHsp70‐2 and TCHsp70‐3. Structural analyses showed that all of the three TCHsp70 cDNAs held the full open reading frame (ORF). Putative protein sequences and a phylogenetic tree suggested that TCHsp70‐1 and TCHsp70‐3 were cytoplasm HSP70 and TCHsp70‐2 was endoplasmic reticulum HSP70. Comparison of deduced amino acid sequences of TCHsp70‐1 and TCHsp70‐3 showed 84.78% identity, TCHsp70‐1 and TCHsp70‐2 showed 57.33% identity, TCHsp70‐2 and TCHsp70‐3 showed 58.26% identity. Real‐time comparative quantitative PCR revealed that the relative expression of TCHsp70‐2 was lower than TCHsp70‐1 and TCHsp70‐3 at each temperature tested. TCHsp70‐1 and TCHsp70‐3 shared a similar expression pattern after cold and heat shock compared with their expression at normal temperature (26 °C), but the mRNA expression of TCHsp70‐1 was significantly higher and lower than that of TCHsp70‐3 at cold and heat shock temperatures (except for 34 °C), respectively. This result possibly indicated the expression patterns of TCHsp70 were affected by their location in different cellular compartments. The results also indicated that three TCHsp70s, especially TCHsp70‐1 and TCHsp70‐3, may play an important role in mediating tolerance to cold, thermal stress for Tetranychus cinnabarinus.
A shut‐down in expression of an insulin‐like peptide, ILP‐1, halts ovarian maturation during the overwintering diapause of the mosquito Culex pipiens
Authors: Sim C. , Denlinger D. L. 
Published: March 2009

AbstractShort day‐length is used to programme adult diapause in the mosquito, Culex pipiens. The downstream endocrine event that halts ovarian maturation is a shut‐down in juvenile hormone (JH) production, and recent evidence suggests that the insulin signalling pathway may be a key upstream player in executing this developmental arrest. Genes encoding insulin‐like peptides‐1, ‐2 and ‐5 were identified in C. pipiens, and we report that transcript levels of insulin‐like peptides‐1 and ‐5 were significantly lower in diapausing females than in their nondiapausing counterparts. Genes encoding both insulin‐like peptides‐1 and ‐5 were suppressed using RNA interference in mosquitoes programmed for nondiapause, and ovarian maturation was monitored. Knocking down insulin‐like peptide‐1 with RNAi in nondiapausing mosquitoes resulted in a cessation of ovarian development akin to diapause, and this arrest in development could be reversed with an application of JH. Knocking down insulin‐like peptide‐5 did not alter ovarian development. These results are consistent with a role for insulin‐like peptide‐1 in the signalling pathway leading from the perception of short day‐lengths to the shut‐down in JH production that characterizes adult diapause in C. pipiens.
Transcriptional diversity and allelic variation in nicotinic acetylcholine receptor subunits of the red flour beetle, Tribolium castaneum
Authors: Rinkevich F. D. , Scott J. G. 
Published: March 2009

AbstractSequence analysis of 168 cDNA clones encoding 12 nicotinic acetylcholine receptor subunits, Tcasα1–Tcasα11 and Tcasβ1, from the red flour beetle, Tribolium castaneum, revealed extensive post‐transcriptional modification and multiple alleles. The greatest diversity was found for Tcasa6, where 18 unique transcripts, as a result of alternative and optional exon usage, were seen. A novel alternative exon 8d was found in one Tcasα6 transcript. Tcasα5 transcripts did not contain previously reported exons 8–10. Six subunits had transcripts that contained unspliced introns, which introduced premature stop codons. Intron 3′ splice site variants were seen at six intron boundaries across five subunits. A‐to‐I RNA editing was seen only in Tcasα6. Alleles were found for all subunit genes, except Tcasα1 and Tcasα10. Transcriptional and allelic diversity are discussed with respect to receptor function and potential interactions with insecticides.
Elucidation of structural changes in soy protein isolate upon heating by Raman spectroscopy
Authors: Herrero A. M. , Jiménez‐Colmenero F. , Carmona P. 
Published: March 2009

SummaryChanges in protein secondary and tertiary structure of soy protein isolate (SPI) upon heating process were investigated by Raman spectroscopy. SPI refrigerated and heated at 70, 100 and 200 °C was analysed. Non‐significant differences in secondary structure (α‐helix, β‐sheet, unordered and turn) were observed in SPI upon heating at these temperatures. However, comparison of the Raman spectra of SPI refrigerated and heated at 70, 100 and 200 °C reveals changes in hydrophobic group environments. An intensity decreasing trend of the 1340 cm−1band attributable to tryptophan vibrations was observed, which involves an increase in solvent exposure of tryptophan residues. The spectral results also showed intensity increasing trends for the 1450 and 2935 cm−1bands of SPI upon heating, which can be ascribed to breaking of hydrophobic contacts and subsequent solvent exposure of the corresponding hydrophobic aliphatic groups. Finally, it was found tertiary structural transitions towards greater proportions of buried tyrosine residues upon heating of SPI.
Assessment of the microbiological conditions of red‐meat carcasses from bacterial counts recovered by sampling via excision or swabbing with cotton wool
Authors: Martínez Bernardo , Celda María Felicidad , Millán María Encarnación , Espacio Aurora , Cano Monserrat , López‐Mendoza María Carmen 
Published: March 2009

SummarySamples from 240 carcasses were collected from four animal species (porcine, ovine, bovine and equine). Two samples were taken from each carcass, one using the excision method (EX) and the other the wet–dry swabbing method (SW). Eight areas from each carcass were sampled. Most of the samples obtained by SW revealed total aerobic viable counts (TVC) levels of between 3.1 and 4.0 log CFU cm−2, while most of the values corresponding to excision were located between 4.1 and 5.0 log CFU cm−2. Moreover, Enterobacteriaceae (EC) counts were only detected above 3.0 log CFU cm−2 in 0.85% of the carcasses when the samples were collected by swabbing, while the excision method revealed that 13.75% of the carcasses presented EC greater than 3.0 log CFU cm−2. TVC and EC by EX revealed statistically significant differences compared to SW, while no significant linear relationship was found between carcass surface bacterial counts obtained by SW and EX.