bluuebunny/crossref_metadata_2025 huggingface dataset:
Numerical simulation of detonation structures using a thermodynamically consistent and fully conservative reactive flow model for multi-component computations
Authors: Cael Giuki , Ng Hoi Dick , Bates Kevin R. , Nikiforakis Nikos , Short Mark
Published: April 2009

This paper presents a simplified reactive multi-gas model for the numerical simulation of detonation waves. The mathematical model is formulated based on a thermodynamically consistent and fully conservative formulation, and is extended to model reactive flow by considering the reactant and product gases as two constituents of the system and modelling the conversion between these by a simple one-step reaction mechanism. This simplified model allows simulations using more appropriate chemico-thermodynamic properties of the combustible mixture and yields close Chapman–Jouguet detonation parameters from detailed chemistry. The governing equations are approximated using a high-resolution finite volume centred scheme in an adaptive mesh refinement code, permitting high-resolution simulations to be performed at flow regions of interest. The algorithm is tested and validated by comparing results to predictions of the one-dimensional linear stability analysis of the steady detonation and through the study of the evolution of two-dimensional cellular detonation waves in gaseous hydrogen-based mixtures.
The physical character of information
Authors: Karnani Mahesh , Pääkkönen Kimmo , Annila Arto
Published: April 2009

The mathematical theory of communication defines information in syntax without reference to its physical representation and semantic significance. However, in an everyday context, information is tied to its representation and its content is valued. The dichotomy between the formal definition and the practical perception of information is examined by the second law of thermodynamics that was recently formulated as an equation of motion. Thermodynamic entropy shows that the physical representation of information is not inconsequential in generation, transmission and processing of information. According to the principle of increasing entropy, communication by dissipative transformations is a natural process among many other evolutionary phenomena that level energy-density differences between components of a communication system and its surroundings. In addition, information-guided processes direct down along descents on free energy landscapes. The non-integrable equation for irreversible processes reveals that there is no universal analytical algorithm to match source to channel. Noise infiltration is also regarded by the second law as an inevitable consequence of energy transduction between a communication system and its surroundings. Communication is invariably associated with misunderstanding because mechanisms and means of information processing at the receiver differ from those at the sender. The significance of information is ascribed to the increase in thermodynamic entropy in the receiver system that results from execution of the received message.
The first-digit frequencies of prime numbers and Riemann zeta zeros
Authors: Luque Bartolo , Lacasa Lucas
Published: April 2009

Prime numbers seem to be distributed among the natural numbers with no law other than that of chance; however, their global distribution presents a quite remarkable smoothness. Such interplay between randomness and regularity has motivated scientists across the ages to search for local and global patterns in this distribution that could eventually shed light on the ultimate nature of primes. In this paper, we show that a generalization of the well-known first-digit Benford's law, which addresses the rate of appearance of a given leading digitdin datasets, describes with astonishing precision the statistical distribution of leading digits in the prime number sequence. Moreover, a reciprocal version of this pattern also takes place in the sequence of the non-trivial Riemann zeta zeros. We prove that the prime number theorem is, in the final analysis, responsible for these patterns.
A new tarkadectine primate from the Eocene of Inner Mongolia, China: phylogenetic and biogeographic implications
Authors: Ni Xijun , Meng Jin , Beard K. Christopher , Gebo Daniel L. , Wang Yuanqing , Li Chuankui
Published: April 2009

TarkaandTarkadectesare Middle Eocene mammals known only from the Rocky Mountains region of North America. Previous work has suggested that they are members of the Plagiomenidae, an extinct family often included in the order Dermoptera. Here we describe a new primate,Tarkops mckennaigen. et sp. nov., from the early Middle Eocene Irdinmanha Formation of Inner Mongolia, China. The new taxon is particularly similar toTarkaandTarkadectes, but it also displays many features observed in omomyids. A phylogenetic analysis based on a data matrix including 59 taxa and 444 dental characters suggests thatTarkops,TarkaandTarkadectesform a monophyletic group—the Tarkadectinae—that is nested within the omomyid clade. Within Omomyidae, tarkadectines appear to be closely related toMacrotarsius. Dermoptera, including extant and extinct flying lemurs and plagiomenids, is recognized as a clade nesting within the polyphyletic group of plesiadapiforms, therefore supporting the previous suggestion that the relationship between dermopterans and primates is as close as that between plesiadapiforms and primates. The distribution of tarkadectine primates on both sides of the Pacific Ocean basin suggests that palaeoenvironmental conditions appropriate to sustain primates occurred across a vast expanse of Asia and North America during the Middle Eocene.
A new basal hadrosauroid dinosaur from the Late Cretaceous of Uzbekistan and the early radiation of duck-billed dinosaurs
Authors: Sues Hans-Dieter , Averianov Alexander
Published: April 2009

Levnesovia transoxianagen. et sp. nov., from the Late Cretaceous (Middle–Late Turonian) of Uzbekistan, is the oldest well-documented taxon referable to HadrosauroideasensuGodefroitet al. It differs from a somewhat younger and closely relatedBactrosaurusfrom Inner Mongolia (China) by a tall sagittal crest on the parietals and the absence of club-shaped dorsal neural spines in adult specimens.Levnesovia,Bactrosaurusand possiblyGilmoreosaurusrepresent the earliest radiation of Hadrosauroidea, which took place during the Cenomanian–Turonian and possibly in North America. The second, Santonian-age radiation of Hadrosauroidea includedAralosaurus, Hadrosauridae and lineages leading toTanius(Campanian) andTelmatosaurus(Maastrichtian). Hadrosauridae appears to be monophyletic, but Hadrosaurinae and Lambeosaurinae originated in North America and Asia, respectively.
A giant ornithomimosaur from the Early Cretaceous of China
Authors: Makovicky Peter J. , Li Daqing , Gao Ke-Qin , Lewin Matthew , Erickson Gregory M. , Norell Mark A.
Published: April 2009

Ornithomimosaurs (ostrich-mimic dinosaurs) are a common element of some Cretaceous dinosaur assemblages of Asia and North America. Here, we describe a new species of ornithomimosaur,
Beishanlong grandis
, from an associated, partial postcranial skeleton from the Aptian-Albian Xinminpu Group of northern Gansu, China.
Beishanlong
is similar to another Aptian-Albian ornithomimosaur,
Harpymimus
, with which it shares a phylogenetic position as more derived than the Barremian
Shenzhousaurus
and as sister to a Late Cretaceous clade composed of
Garudimimus
and the Ornithomimidae.
Beishanlong
is one of the largest definitive ornithomimosaurs yet described, though histological analysis shows that the holotype individual was still growing at its death. Together with the co-eval and sympatric therizinosaur
Suzhousaurus
and the oviraptorosaur
Gigantraptor
,
Beishanlong
provides evidence for the parallel evolution of gigantism in separate lineages of beaked and possibly herbivorous coelurosaurs within a short time span in Central Asia.
Bmi-1 regulates the Ink4a/Arf locus to control pancreatic β-cell proliferation
Authors: Dhawan Sangeeta , Tschen Shuen-Ing , Bhushan Anil
Published: April 2009

The molecular mechanisms that regulate the age-induced increase of p16INK4a expression associated with decreased β-cell proliferation and regeneration are not well understood. We report that in aged islets, derepression of the Ink4a/Arf locus is associated with decreased Bmi-1 binding, loss of H2A ubiquitylation, increased MLL1 recruitment, and a concomitant increase in H3K4 trimethylation. During β-cell regeneration these histone modifications are reversed resulting in reduced p16INK4a expression and increased proliferation. We suggest that PcG and TrxG proteins impart a combinatorial code of histone modifications on the Ink4a/Arf locus to control β-cell proliferation during aging and regeneration.
Compromised stability of DNA methylation and transposon immobilization in mosaic Arabidopsis epigenomes
Authors: Reinders Jon , Wulff Brande B.H. , Mirouze Marie , Marí-Ordóñez Arturo , Dapp Mélanie , Rozhon Wilfried , Bucher Etienne , Theiler Grégory , Paszkowski Jerzy
Published: April 2009

Transgenerational epigenetic inheritance has been defined by the study of relatively few loci. We examined a population of recombinant inbred lines with epigenetically mosaic chromosomes consisting of wild-type and CG methylation-depleted segments (epiRILs). Surprisingly, transposons that were immobile in the parental lines displayed stochastic movement in 28% of the epiRILs. Although analysis after eight generations of inbreeding, supported by genome-wide DNA methylation profiling, identified recombined parental chromosomal segments, these were interspersed with unexpectedly high frequencies of nonparental methylation polymorphism. Hence, epigenetic inheritance in hybrids derived from parents with divergent epigenomes permits long-lasting epi-allelic interactions that violate Mendelian expectations. Such persistently “unstable” epigenetic states complicate linkage-based epigenomic mapping. Thus, future epigenomic analyses should consider possible genetic instabilities and alternative mapping strategies.
Chloroplast Photooxidation-Induced Transcriptome Reprogramming in ArabidopsisimmutansWhite Leaf Sectors
Authors: Aluru Maneesha R. , Zola Jaroslaw , Foudree Andrew , Rodermel Steven R.
Published: April 2009

Arabidopsis (Arabidopsis thaliana) immutans (im) has green and white sectoring due to the action of a nuclear recessive gene, IMMUTANS. The green sectors contain normal-appearing chloroplasts, whereas the white sectors contain abnormal chloroplasts that lack colored carotenoids due to a defect in phytoene desaturase activity. Previous biochemical and molecular characterizations of the green leaf sectors revealed alterations suggestive of a source-sink relationship between the green and white sectors of im. In this study, we use an Affymetrix ATH1 oligoarray to further explore the nature of sink metabolism in im white tissues. We show that lack of colored carotenoids in the im white tissues elicits a differential response from a large number of genes involved in various cellular processes and stress responses. Gene expression patterns correlate with the repression of photosynthesis and photosynthesis-related processes in im white tissues, with an induction of Suc catabolism and transport, and with mitochondrial electron transport and fermentation. These results suggest that energy is derived via aerobic and anaerobic metabolism of imported sugar in im white tissues for growth and development. We also show that oxidative stress responses are largely induced in im white tissues; however, im green sectors develop additional energy-dissipating mechanisms that perhaps allow for the formation of green sectors. Furthermore, a comparison of the transcriptomes of im white and norflurazon-treated white leaf tissues reveals global as well as tissue-specific responses to photooxidation. We conclude that the differences in the mechanism of phytoene desaturase inhibition play an important role in differentiating these two white tissues.
Variations in the Composition of Gelling Agents Affect Morphophysiological and Molecular Responses to Deficiencies of Phosphate and Other Nutrients
Authors: Jain Ajay , Poling Michael D. , Smith Aaron P. , Nagarajan Vinay K. , Lahner Brett , Meagher Richard B. , Raghothama Kashchandra G.
Published: April 2009

Low inorganic phosphate (Pi) availability triggers an array of spatiotemporal adaptive responses in Arabidopsis (Arabidopsis thaliana). There are several reports on the effects of Pi deprivation on the root system that have been attributed to different growth conditions and/or inherent genetic variability. Here we show that the gelling agents, largely treated as inert components, significantly affect morphophysiological and molecular responses of the seedlings to deficiencies of Pi and other nutrients. Inductively coupled plasma-mass spectroscopy analysis revealed variable levels of elemental contaminants not only in different types of agar but also in different batches of the same agar. Fluctuating levels of phosphorus (P) in different agar types affected the growth of the seedlings under Pi-deprivation condition. Since P interacts with other elements such as iron, potassium, and sulfur, contaminating effects of these elements in different agars were also evident in the Pi-deficiency-induced morphological and molecular responses. P by itself acted as a contaminant when studying the responses of Arabidopsis to micronutrient (iron and zinc) deficiencies. Together, these results highlighted the likelihood of erroneous interpretations that could be easily drawn from nutrition studies when different agars have been used. As an alternative, we demonstrate the efficacy of a sterile and contamination-free hydroponic system for dissecting morphophysiological and molecular responses of Arabidopsis to different nutrient deficiencies.
Advances in the understanding of congenital amegakaryocytic thrombocytopenia
Authors: Ballmaier Matthias , Germeshausen Manuela
Published: April 2009

Congenital amegakaryocytic thrombocytopenia (MIM #604498) is an extremely rare inherited bone marrow failure syndrome, usually presenting as a severe thrombocytopenia at birth due to ineffective megakaryocytopoiesis and no characteristic physical anomalies. Usually the isolated thrombocytopenia progresses to pancytopenia during the first years of life. The only curative therapy to date is haematopoietic stem cell transplantation. Most of the cases of congenital amegakaryocytic thrombocytopenia are caused by defective expression or function of the thrombopoietin receptor due to homozygous or compound heterozygous mutations in the gene MPL. The essential roles of thrombopoietin as a lineage specific regulator of platelet production and as a regulator of haematopoietic stem cell function are reflected in the haematological defects seen in affected individuals.
Physicochemical properties of ferumoxytol, a new intravenous iron preparation
Authors: Balakrishnan V. S. , Rao M. , Kausz A. T. , Brenner L. , Pereira B. J. G. , Frigo T. B. , Lewis J. M.
Published: April 2009

Background  Intravenous iron is a critical component of anaemia management. However, currently available preparations have been associated with the release of free iron, a promoter of bacterial growth and oxidative stress.

Materials and methods  We determined the molecular weight, dialysability and capacity for free iron release of ferumoxytol, a semi‐synthetic carbohydrate‐coated superparamagnetic iron oxide nanoparticle. Ferumoxytol was compared with three intravenous iron preparations in clinical use: iron dextran (low molecular weight), sodium ferric gluconate and iron sucrose. Intravenous iron preparations were also incubated in rat, and pooled human sera (at concentrations of 600 μM and 42 μg mL−1 respectively) from healthy subjects.

Results  The molecular weight of ferumoxytol was 731 kDa. The relative order of molecular weight was as follows: ferumoxytol > iron dextran > iron sucrose > sodium ferric gluconate. The least ultrafilterable iron was observed with ferumoxytol and the most with ferric gluconate. The least dialysable free iron was observed with ferumoxytol and the most with ferric gluconate. Incubation of intravenous iron preparations in rat or pooled human sera demonstrated minimal free iron release with ferumoxytol. The order of catalytic iron release as detected by the bleomycin detectable iron assay was as follows: ferumoxytol < iron dextran < iron sucrose < ferric gluconate. A similar trend was observed for the in vivo serum concentration of free iron in rats.

Conclusions  In vitro observations from these experiments suggest that ferumoxytol has a favourable profile in terms of tendency to release free iron, in comparison with currently available intravenous iron preparations.
Triggering of suicidal erythrocyte death by radiocontrast agents
Authors: Föller M. , Sopjani M. , Schlemmer H. P. , Claussen C. D. , Lang F.
Published: April 2009

Background  According to in vitro observations, gadolinium‐containing magnetic resonance (MRT) contrast agents stimulate suicidal cell death or apoptosis. Similar to nucleated cells, erythrocytes may undergo suicidal death or eryptosis, characterized by cell shrinkage and cell membrane scrambling with phosphatidylserine (PS) exposure at the erythrocyte surface. Eryptosis is triggered by increased cytosolic Ca2+‐activity. This study explored whether gadolinium‐containing MRT contrast agents stimulate eryptosis.

Materials and methods  Annexin V‐binding reflecting PS exposure and forward scatter reflecting cell volume were determined in erythrocytes within freshly drawn blood from patients (8♀, 3♂, 29–72 years) prior to and 10 min after administration of gadoterate meglumine (0·1 mmol kg−1 b.w. Dotarem®; six patients) or gadobenate dimeglumine (0·05 mmol kg−1 bw Multi Hance®; five patients). In a separate series, eryptosis was determined prior to and following in vitro incubation of erythrocytes from 16 blood donors for 4 h with gadoterate meglumine (5 mM Dotarem®) or gadobenate dimeglumine (5 mM Multi Hance®). Finally, eryptosis and Fluo3 fluorescence reflecting cytosolic Ca2+ were determined in vitro following exposure to Gd3+. Data were analysed using paired t‐test or anova with Tukey’s test as post‐test.

Results  The MRT contrast agents such as gadoterate meglumine (Dotarem®) and gadobenate dimeglumine (Multi Hance®) significantly increased the percentage of eryptotic cells. Moreover, in vitro exposure to gadoterate meglumine (5 mM), gadobenate dimeglumine (5 mM) or Gd3+ (1·9 μM) stimulated eryptosis in vitro. The effect of Gd3+ was paralleled by increase in cytosolic Ca2+‐activity.

Conclusions  MRT contrast agents may stimulate suicidal erythrocyte death or eryptosis in vitro and in vivo.
Effect of polymerized‐type I collagen in knee osteoarthritis. II. In vivo study
Authors: Furuzawa‐Carballeda J. , Muñoz‐Chablé O. A. , Macías‐Hernández S. I. , Agualimpia‐Janning A.
Published: April 2009

Background  Polymerized‐Type I Collagen (Polymerized‐Collagen) is an anti‐inflammatory and a tissue regenerator biodrug. The aim of the study was to evaluate the efficacy and safety of intra‐articular injections of Polymerized‐Collagen in patients with knee osteoarthritis (OA).

Methods and design  Patients (n = 53) were treated with 12 intra‐articular injections of 2 mL of Polymerized‐Collagen (n = 27) or 2 mL of placebo (n = 26) during 6 months. Follow up period was 6 months. The primary endpoints included Western Ontario and McMaster University Osteoarthritis Index, Lequesne index, and pain intensity on a visual analogue scale (VAS). Secondary outcomes were patient global score, investigator global score and drug evaluation. Clinical improvement was determined if the decrease in pain exceeds 20 mm on a VAS and patients achieved at least 20% of improvement from baseline. Urinary levels of C‐terminal crosslinking telopeptide of collagen type II (CTXII) and serum high‐sensitivity C‐reactive protein (hsCRP) were determined by enzyme immunoassays. Statistical analysis was performed by intention to treat.

Results  Polymerized‐Collagen was safe and well tolerated. Patients had a statistically significant improvement (P < 0·05) from baseline vs. Polymerized‐Collagen and vs. placebo at 6 months in: Lequesne Index (13·1 ± 0·5 vs. 7·1 ± 0·7 vs. 9·6 ± 0·8; P = 0·027), WOMAC (9·0 ± 0·5 vs. 4·0 ± 0·6 vs. 5·80 ± 0·8; P = 0·032), patient VAS (60·0 ± 2·6 vs. 20·6 ± 2·4 vs. 36·1 ± 4·5; P = 0·003), physician VAS (49·8 ± 1·9 vs. 16·8 ± 2·9 vs. 29·8 ± 2·9; P = 0·002), patient global score (1·08 ± 0·1 vs. 2·7 ± 0·1 vs. 1·9 ± 0·2; P = 0·028) and analgesic usage (30·1 ± 9·4 vs. 11·0 ± 3·4 vs. 17·9 ± 4·9; P = 0·001). This improvement was persistent during the follow up. A threefold increase in CTXII was determined in placebo group. No differences were found on hs CRP and incidence of adverse events between groups.

Conclusion  Polymerized‐Collagen is safe and effective in the treatment of knee OA.
Stocking strategies
Authors: COWX I.G.
Published: April 2009

Abstract  Stocking, transfer and introduction of fish are commonly used to mitigate loss of stocks, enhance recreational or commercial catches, restore fisheries or to create new fisheries. However, many stocking programmes are carried out without definition of objectives or evaluation of the potential or actual success of the exercise. This paper describes a strategic approach to stocking aimed at maximizing the potential benefits. A protocol is discussed which reviews factors such as source of fish, stocking density, age and size of fish at stocking, timing of stocking and mechanism of stocking. The potential genetic, ecological and environmental impacts of stocking are described.
Models for comparing average first‐year growth in length of freshwater fish
Authors: KUBECKA J.
Published: April 2009

Abstract  Logistic curves of the average growth in length were elaborated for young‐of‐the‐year perch, Perca fluviatilis L., zander. Stizostedion lucioperca (L.), ruffe, Gymnocephalus cernua (L.), bream, Abramis brama (L.), and roach, Rutilus rutilus (L.), using data from 62 localities. Mean relative deviation from this average growth (MRDAG) is proposed as a simple and reliable indicator of growth rate. The MRDAG for perch, zander, bream and roach showed a significant negative linear relationship with the geographical latitude.
Short‐term habitat use by young grayling, Thymallus thymallus L., under variable flow conditions in an experimental stream
Authors: VALENTIN S. , SEMPESKI P. , SOUCHON Y. , GAUDIN P.
Published: April 2009

Abstract  In an experimental stream containing available refuge zones, moderate and instantaneous flow variations did not cause high mortality or substantial increase in downstream migration of 2‐month‐old grayling, Thymallus thymallus L. Fish were able to react rapidly to spate simulations by a change in space utilization determined by changes in water velocity patterns. Reaction of fish to these experimental flow variations corresponded to a refuge strategy, i.e. seeking shelter and minimizing the distance to find it.
Sea‐ranching of brown trout,Salmo truttaL.
Authors: JONSSON N. , JONSSON B. , HANSEN L.P.
Published: April 2009

Abstract In total, 8211 1‐year‐old and 14839 2‐year‐old hatchery‐reared brown trout,Salmo truttaL., from 11 stocks were released at the mouth of the River Imsa, southwestern Norway. The recapture rates and total estimated yield were higher for 2‐ than 1‐year‐old trout, although recapture rates varied between years of release and stocks. The recapture rate increased with mean individual weight at time of release. Total estimated yield from the individual groups of 1+ trout ranged from 2 to 20 kg per 1000 trout released and for 2+ trout between 11 and 250 kg per 1000 fish released. In all cases, yields were lower than the economic break‐even yield. Most fish were recaptured the year of release (89.2% of 2+ and 76.2% of 1+ trout). Almost 31% of the recaptures were caught at sea and 69% in fresh water; 95.8% of the latter were taken in the River Imsa trap.
Diet and food utilization in Oreochromis esculentus (Graham) in Lake Kanyaboli, Kenya
Authors: OPIYO S. V. , DADZIE S.
Published: April 2009

Abstract  Blue‐green algae (Cyanophyta) and green algae (Chlorophyta) were the principal food items ingested by Oreochromis esculentus (Graham) in Lake Kanyaboli. Diatoms (Bacillariophyta), euglenoids (Euglenophyta) and zooplankton were also consistently present in the diet in small quantities. O. esculentus of different sizes fed on similar food items in the lake. The species fed actively during the day, from 0700 h until 1700 h when peak feeding activity occurred. Thereafter, digestion took place steadily until 0600 h, when 90% of the fish had empty stomachs. The diet composition remained the same throughout the year, as did the composition of phytoplankton in the lake. O. esculentus tended to select and digest the diatoms and zooplankton and, to some extent, the euglenoids. Blue‐green and green algae were the least utilized food items and passed through the gut undigested.
Discrimination of Norwegian farmed, ranched and wild‐origin Atlantic salmon, Salmo salar L., by image processing
Authors: FRIEDLAND K.D. , ESTEVES C. , HANSEN L. P. , LUND R. A.
Published: April 2009

Abstract  A method of distinguishing between farmed, ranched and wild‐origin Atlantic salmon, Salmo salar L., using scale morphology is proposed. Circuli spacing and scale texture data, as expressed as a Fourier transform of transmission luminescent patterns. were extracted by image processing. Spacing patterns and texture features were most distinct for wild salmon compared with the other two groups. Three‐group quadratic discriminant function models were developed using different combinations of data types. The most efficient model to separate the three groups had a classification efficiency of 74%. When models were simplified to two groups, farmed and wild, efficiency increased to 90%, thus reflecting the feature overlap between farmed and ranched groups. The method may be a useful tool for more objective and efficient classification of wild versus husbandry‐origin salmon. However, it should be stressed that farmed salmon that escape at the smolt stage are still problematic.
Invasions and niche width: does niche width of an introduced crayfish differ from a native crayfish?
Authors: OLSSON KARIN , STENROTH PATRIK , NYSTRÖM PER , GRANÉLI WILHELM
Published: April 2009

1. Human activities have promoted the spread of species worldwide. Several crayfish species have been introduced into new areas, posing a threat to native crayfish and other biota. Invader success may depend on the ability to utilise a wide variety of habitats and resources. Successful invaders are generally expected to have broader niches and to be more plastic than non‐invasive species.

2. Using stable isotope ratios of carbon and nitrogen we compared the niche widths of native noble crayfish and introduced signal crayfish, a successful invader of Swedish streams. The calculation of niche width took account of between‐site differences in basal resource isotope signature ranges. We also assessed whether population density, prey biomass or prey diversity affected niche width.

3. At the species level, signal crayfish had twice the niche width of noble crayfish. However, individual populations of noble crayfish and signal crayfish in Swedish streams had similar niche widths. This suggests that signal crayfish has greater plasticity with respect to habitat utilisation and feeding than noble crayfish. Niche width in both species correlated positively with benthic invertebrate biomass and diversity, indicating that animal food sources are important for crayfish.

4. We find that assessing niche width in relation to invader success can be a useful tool trying to predict the impact of invasions on different scales. The findings in this study suggest that invaders and natives will have a similar impact on the stream scale whereas the invader will have a larger impact on the regional scale due to the ability to utilise a wider range of streams.
Effects of macrophytes on feeding and life‐history traits of the invasive apple snail Pomacea canaliculata
Authors: QIU JIAN‐WEN , KWONG KING‐LUN
Published: April 2009

1. Biological invasions have become a serious threat to ecosystems worldwide. Various factors can contribute to the success of biological invasion. We examined how different macrophyte food affected feeding and life‐history traits of the invasive herbivorous snail Pomacea canaliculata, and whether differences in snail life‐history traits could explain its successful infestation of agricultural and non‐agricultural wetlands in Asia.

2. We tested five cultivated and five wild semi‐aquatic macrophytes. Snail daily feeding rate varied substantially with plant species, ranging from 1.3% to 22% of its body mass. Snails fed with four (Amaranthus gangeticus, Apium graveolens dulce, Ipomoea aquatica and Nasturtium officinale) of the five cultivated macrophyte species exhibited high survivorship, fast growth and high fecundity. Snails fed with Colocasia esculenta, however, grew poorly, did not reproduce and eventually died.

3. Of the five wild species (Eichhornia crassipes, Ludwigia adscendens, Murdannia nudiflora, Myriophyllum aquaticum and Polygonum hydropiper), M. nudiflora supported a high snail survival, but snails had slower growth and lower fecundity than those reared on the four palatable cultivated species. Snails fed with L. adscendens grew substantially slower than those fed with M. nudiflora, and produced only a small clutch of eggs. Snails fed with E. crassipes, M. aquaticum and P. hydropiper had very low survivorship, grew very little and did not reproduce.

4. We determined six plant properties and their correlation with the feeding, growth and reproduction of the apple snails. Cultivated macrophytes in general had a higher nutritional value and lower physical and chemical defences. Phenolic content was negatively correlated with snail feeding rate, while plant nitrogen and phosphorus contents were positively correlated with snail egg production and growth, respectively.

5. These results indicate that, due to their higher nutritional value and lower chemical and physical defences, cultivated macrophytes are in general desirable for the apple snail which may partly explain its successful invasion into wet agricultural areas in Asia. This snail may also selectively graze poorly defended wild macrophytes in non‐agricultural wetlands, leading to changes in floral diversity and wetland functioning. Management of this and other apple snails with similar life‐history traits should thus focus on the prevention of their further spread.
The sensitive hare: sublethal effects of predator stress on reproduction in snowshoe hares
Authors: Sheriff Michael J. , Krebs Charles J. , Boonstra Rudy
Published: April 2009

1. Prey responses to high predation risk can be morphological or behavioural and ultimately come at the cost of survival, growth, body condition, or reproduction. These sub‐lethal predator effects have been shown to be mediated by physiological stress. We tested the hypothesis that elevated glucocorticoid concentrations directly cause a decline in reproduction in individual free‐ranging female snowshoe hares,Lepus americanus. We measured the cortisol concentration from each dam (using a faecal analysis enzyme immunoassay) and her reproductive output (litter size, offspring birth mass, offspring right hind foot (RHF) length) 30 h after birth.

2. In a natural monitoring study, we monitored hares during the first and second litter from the population peak (2006) to the second year of the decline (2008). We found that faecal cortisol metabolite (FCM) concentration in dams decreased 52% from the first to the second litter. From the first to the second litter, litter size increased 122%, offspring body mass increased 130%, and offspring RHF length increased 112%. Dam FCM concentrations were inversely related to litter size (r2 = 0·19), to offspring birth mass (r2 = 0·32), and to offspring RHF length (r2 = 0·64).

3. In an experimental manipulation, we assigned wild‐caught, pregnant hares to a control and a stressed group and held them in pens. Hares in the stressed group were exposed to a dog 1–2 min every other day before parturition to simulate high predation risk. At parturition, unsuccessful‐stressed dams (those that failed to give birth to live young) and stressed dams had 837% and 214%, respectively, higher FCM concentrations than control dams. Of those females that gave birth, litter size was similar between control and stressed dams. However, offspring from stressed dams were 37% lighter and 16% smaller than offspring from control dams. Increasing FCM concentration in dams caused the decline of offspring body mass (r2 = 0·57) and RHF (r2 = 0·52).

4. This is the first study in a free‐ranging population of mammals to show that elevated, predator‐induced, glucocorticoid concentrations in individual dams caused a decline in their reproductive output measured both by number and quality of offspring. Thus, we provide evidence that any stressor, not just predation, which increases glucocorticoid concentrations will result in a decrease in reproductive output.
Differentiating characteristics of deafblindness and autism in people with congenital deafblindness and profound intellectual disability
Authors: Hoevenaars‐van den Boom M. A. A. , Antonissen A. C. F. M. , Knoors H. , Vervloed M. P. J.
Published: April 2009

Background  In persons with deafblindness, it is hard to distinguish autism spectrum disorders from several deafblind specific behaviours caused by the dual sensory impairments, especially when these persons are also intellectually disabled. As a result, there is an over‐diagnosis of autism in persons who are deafblind leading to unsuitable interventions.

Methods  Autism as specified by the DSM‐IV was studied in 10 persons with congenital deafblindness with profound intellectual disabilities. Behaviours of people with deafblindness and autism (n = 5) and of people with deafblindness without autism (n = 5) were observed in a semi‐standardised assessment.

Results  All people with deafblindness showed impairments in social interaction, communication and language. In contrast to persons without autism, people with deafblindness and autism showed significantly more impairments in reciprocity of social interaction, quality of initiatives to contact and the use of adequate communicative signals and functions. No differences between the groups were found for quantity and persistence of stereotyped behaviour, quality of play and exploration and adequate problem‐solving strategies.

Conclusions  This study indicates that there are some possibilities to differentiate autism from behaviours specific for deafblindness. It also confirms the large overlap in overt behaviours between people with deafblindness and persons with autism.
Persistent parvovirus B19 infection detected by specific CD4+ T‐cell responses in a patient with hepatitis and polyarthritis
Authors: Pongratz G. , Lindner J. , Modrow S. , Schimanski S. , Schölmerich J. , Fleck M.
Published: April 2009

We, here, report the case of a parvovirus B19 infection in an immunocompetent male patient presenting with acute hepatitis and polyarthritis. To follow the course of infection, we used a previously established enzyme‐linked immunosorbent spot assay (ELISPOT) technique to detect CD4+ T cells specific for viral proteins. Even though symptoms of arthritis and hepatitis resolved in the immunocompetent individual within a few weeks, viral DNA in serum and CD4+ T cells specific for the viral protein VP1 unique region were still detectable more than 6 month after the onset of symptoms, thus pointing to a persistent state of infection. On the basis of this observation, we hypothesize that the intensity of liver involvement correlates with the likelihood of developing persistent parvovirus B19 infection. The described ELISPOT technique to detect virus‐specific CD4+ T cells provides an excellent tool to analyse the state of parvovirus B19 infection for future studies to test this hypothesis.
Antagonism between local dispersal and self‐incompatibility systems in a continuous plant population
Authors: CARTWRIGHT REED A.
Published: April 2009

Many self‐incompatible plant species exist in continuous populations in which individuals disperse locally. Local dispersal of pollen and seeds facilitates inbreeding because pollen pools are likely to contain relatives. Self‐incompatibility promotes outbreeding because relatives are likely to carry incompatible alleles. Therefore, populations can experience an antagonism between these forces. In this study, a novel computational model is used to explore the effects of this antagonism on gene flow, allelic diversity, neighbourhood sizes, and identity by descent. I confirm that this antagonism is sensitive to dispersal levels and linkage. However, the results suggest that there is little to no difference between the effects of gametophytic and sporophytic self‐incompatibility systems (GSI and SSI) on unlinked loci. More importantly, both GSI and SSI affect unlinked loci in a manner similar to obligate outcrossing without mating types. This suggests that the primary evolutionary impact of self‐incompatibility systems may be to prevent selfing, and prevention of biparental inbreeding might be a beneficial side‐effect.
Colour variation is incongruent with mitochondrial lineages: cryptic speciation and subsequent diversification in a Gulf of California reef fish (Teleostei: Blennioidei)
Authors: LIN H‐C. , SÁNCHEZ‐ORTIZ C. , HASTINGS P. A.
Published: April 2009

The Gulf of California endemic reef fish, Acanthemblemaria crockeri (Blennioidei, Chaenopsidae), reportedly has two colour morphs, one with melanic lateral spots (‘Gulf’ morph) and one with orange spots (‘Cape’ morph). In this study, we recorded colour morph in both males and females and collected mitochondrial DNA sequence data for cytochrome c oxidase I (COI) and tRNA‐Pro/D‐loop of specimens from throughout the Gulf to explore the genetic basis of the colour morphs. Two highly divergent (HKY + I distance = 11.9% for COI), reciprocally monophyletic lineages were identified, consistent with the presence of two parapatric species. A 30‐km gap between the distributions of mitochondrial lineages roughly corresponds to a hypothesized former seaway across the Baja California peninsula north of La Paz, although the estimated divergence time (1.84 million years ago) is more recent than the hypothetical seaway (3–4 million years ago). Surprisingly, the distribution of mitochondrial species is not congruent with the distribution of either male or female colour morphs. Our analysis also revealed significant population differentiation within both species and no shared haplotypes among populations. The northern Gulf species includes four populations (NB, CB, NM and CM) corresponding to northern and central Baja and northern and central mainland sites, while the Cape species includes two populations (SB and SM) corresponding to the Baja and mainland sides of the southern Gulf. The NB/CB division corresponds to a hypothesized Plio–Pleistocene mid‐peninsular seaway. The level of genetic divergence documented in this lineage is extraordinary for a marine fish with a pelagic larval stage within a semi‐enclosed basin.
Multilocus heterozygosity, parental relatedness and individual fitness components in a wild mountain goat,Oreamnos americanuspopulation
Authors: MAINGUY JULIEN , CÔTÉ STEEVE D. , COLTMAN DAVID W.
Published: April 2009

Matings between relatives lead to a decrease in offspring genetic diversity which can reduce fitness, a phenomenon known as inbreeding depression. Because alpine ungulates generally live in small structured populations and often exhibit a polygynous mating system, they are susceptible to inbreeding. Here, we used marker‐based measures of pairwise genetic relatedness and inbreeding to investigate the fitness consequences of matings between relatives in a long‐term study population of mountain goats (Oreamnos americanus) at Caw Ridge, Alberta, Canada. We first assessed whether individuals avoided mating with kin by comparing actual and random mating pairs according to their estimated genetic relatedness, which was derived from 25 unlinked polymorphic microsatellite markers and reflected pedigree relatedness. We then examined whether individual multilocus heterozygosityH, used as a measure of inbreeding, was predicted by parental relatedness and associated with yearling survival and the annual probability of giving birth to a kid in adult females. Breeding pairs identified by genetic parentage analyses of offspring that survived to 1 year of age were less genetically related than expected under random matings. Parental relatedness was negatively correlated with offspringH, and more heterozygous yearlings had higher survival to 2 years of age. The probability of giving birth was not affected byHin adult females. Because kids that survived to yearling age were mainly produced by less genetically related parents, our results suggest that some individuals experienced inbreeding depression in early life. Future research will be required to quantify the levels of gene flow between different herds, and evaluate their effects on population genetic diversity and dynamics.
Glacial oceanographic contrasts explain phylogeography of Australian bull kelp
Authors: FRASER CERIDWEN I. , SPENCER HAMISH G. , WATERS JONATHAN M.
Published: April 2009

The evolutionary effects of Southern Hemisphere Pleistocene oceanographic conditions — marked by fluctuations in sea levels and water temperatures, and redirected currents — are poorly understood. The southeastern tip of Australia presents an intriguing model system for studying the biological impacts of palaeoceanography. In particular, contrasting oceanographic conditions that existed on eastern vs. western sides of the Bassian Isthmus during Pleistocene glacial periods allow for natural comparisons between putative refugial vs. re‐invading populations. Whereas many western Tasmanian marine taxa were likely eliminated by cold subantarctic water during the last glacial period, eastern Tasmanian populations would have persisted in relatively warm temperatures mediated by the ongoing influence of the East Australian Current (EAC). Here we test for the effects of contrasting palaeoceanographic conditions on endemic bull kelp, Durvillaea potatorum, using DNA sequence analysis (COI; rbcL) of more than 100 individuals from 14 localities in southeastern Australia. Phylogenetic reconstructions reveal a deep (maximum divergence 4.7%) genetic split within D. potatorum, corresponding to the ‘eastern’ and ‘western’ geographical regions delimited by the Bassian Isthmus, a vicariant barrier during low Pleistocene sea levels. Concordant with the western region's cold glacial conditions, samples from western Tasmania and western Victoria are genetically monomorphic, suggesting postglacial expansion from a mainland refugium. Eastern samples, in contrast, comprise distinct regional haplogroups, suggesting the species persisted in eastern Tasmania throughout recent glacial periods. The deep east–west divergence seems consistent with earlier reports of morphological differences between ‘western’ and ‘eastern’D. potatorum, and it seems likely that these forms represent reproductively isolated species.
Investigation of regulatory factors required for alternative oxidase production in Neurospora crassa
Authors: Chae Michael S. , Nargang Frank E.
Published: April 2009

Alternative oxidase (AOX) has been found in a large number of filamentous fungi and yeasts with the notable exceptions of Saccharomyces cerevisiae and Schizosaccharomyces pombe. In virtually all of these fungi, AOX is induced by stresses on the cell that compromise the efficiency of the standard mitochondrial electron transport chain. As AOX is encoded in the nucleus and the signals that induce its expression originate in mitochondria, induction of the enzyme provides a classic example of retrograde regulation where signals from mitochondria influence the expression of nuclear genes. We have previously isolated mutants in Neurospora crassa that are incapable of inducing AOX. The genes affected in two of these mutants, aod‐2 and aod‐5, encode zinc cluster transcription factors that act to control expression of the AOX by binding to an alternative oxidase induction motif (AIM) found in the promoter of the AOX structural gene. We have now used pull‐down assays and size‐exclusion chromatography to demonstrate that the AOD2 and AOD5 proteins physically interact in vitro. In addition, we have shown that a homolog of the RTG2 protein, which is part of a classic retrograde signaling pathway in S. cerevisiae, is not required for AOX regulation in N. crassa.
Proptosis in a post‐renal transplant patient with disseminated tuberculosis
Authors: Vishnubhotla S. , Siddhartha B. , Sivramakrishna G. , Lakshmi A.Y. , Kumaraswamy R.M.
Published: April 2009

Abstract: A 55‐year‐old male patient 13 years post living‐related renal transplant on immunosuppressives presented with prolonged fever and a recent protrusion of the right eyeball. Evaluation revealed disseminated tuberculosis with a tuberculoma in the right orbit.
Heritability, covariation and natural selection on 24 traits of common evening primrose (Oenothera biennis) from a field experiment
Authors: JOHNSON M. T. J. , AGRAWAL A. A. , MARON J. L. , SALMINEN J.‐P.
Published: April 2009

This study explored genetic variation and co‐variation in multiple functional plant traits. Our goal was to characterize selection, heritabilities and genetic correlations among different types of traits to gain insight into the evolutionary ecology of plant populations and their interactions with insect herbivores. In a field experiment, we detected significant heritable variation for each of 24 traits of Oenothera biennis and extensive genetic covariance among traits. Traits with diverse functions formed several distinct groups that exhibited positive genetic covariation with each other. Genetic variation in life‐history traits and secondary chemistry together explained a large proportion of variation in herbivory (r2 = 0.73). At the same time, selection acted on lifetime biomass, life‐history traits and two secondary compounds of O. biennis, explaining over 95% of the variation in relative fitness among genotypes. The combination of genetic covariances and directional selection acting on multiple traits suggests that adaptive evolution of particular traits is constrained, and that correlated evolution of groups of traits will occur, which is expected to drive the evolution of increased herbivore susceptibility. As a whole, our study indicates that an examination of genetic variation and covariation among many different types of traits can provide greater insight into the evolutionary ecology of plant populations and plant–herbivore interactions.
Getting in shape: adaptation and phylogenetic inertia in morphology of Australian anuran larvae
Authors: VAN BUSKIRK J.
Published: April 2009

The external morphology of frog larvae is predicted to vary among habitats, for a variety of functional reasons. I performed a phylogenetic comparative study to test whether correlations between habitat and the shape of the tadpole and its oral disc are adaptive in 82 species from south‐eastern Australia in the families Hylidae and Myobatrachidae. Habitat distributions and phylogenetic relationships were compiled from the literature and shape was quantified using geometric morphometric analysis of published drawings. Results indicate that shape evolved towards different optima in different habitats while also showing appreciable levels of phylogenetic inertia. Within myobatrachids, evolution of terrestrial tadpoles was associated with a short and shallow head/body and a shallow tail. In aquatic species, the use of benthic microhabitats was correlated with a long shallow tail, dorsal eye position, shallow head/body and ventral mouth with robust jaw sheaths. Even traits with evidence for adaptation evolved slowly in response to habitat shifts, usually requiring ≥10 million years to evolve half‐way to a new optimum. Although these findings support adaptive evolution of tadpole body form, they also highlight a strong influence of ancestral character states and indicate that phenotypes in extant species are partly maladaptive.