bluuebunny/crossref_metadata_2025_split huggingface dataset:
Importance of nest attributes in the conservation of endemic birds of the Juan Fernández Archipelago, Chile
Authors: HAHN INGO J. , VERGARA PABLO M. , RÖMER UWE 
Published: May 2011

SummaryUnderstanding the particular nesting ecology of island endemic species represents the first step in identifying suitable micro-habitats and establishing efficient management programmes. This could become even more important when island bird assemblages are prone to invasion by ecologically similar species that may eventually cause niche compression or the extirpation of species already present on the island. In this study we describe the nesting ecology of both native and introduced landbird species of the Juan Fernández Islands and determine the extent to which native species could be negatively affected by alien competitors. A total of 119 nests belonging to the 11 resident landbird species were analysed. Landbirds exhibited a wide range of nesting habitat preferences on the different islands, covering different vegetation types, altitudes and ecosystems. By means of a cluster analysis we determined that competition between alien and endemic species apparently does not represent an important factor affecting resource use by endemic birds. Endemic landbirds preferred sites comparatively higher above the ground, with a greater slope and a larger level of shelter, than alien species. The introduced hummingbird, the Green-backed FirecrownSephanoides sephaniodes, had different nesting preferences to the endemic Juan Fernandez FirecrownS. fernandensis, whereas the House SparrowPasser domesticusselected nest sites located in populated areas, suggesting that both alien species may not be competing with endemic passerines for nest sites. However, urgent measures are necessary to reduce the potential predation risk on Juan Fernandez Firecrown nests by the alien Austral ThrushTurdus falcklandii.
New heterodontosaurid specimens from the Lower Jurassic of southern Africa and the early ornithischian dinosaur radiation
Authors: Porro Laura B. , Butler Richard J. , Barrett Paul M. , Moore-Fay Scott , Abel Richard L. 
Published: May 2011

ABSTRACTHeterodontosaurids are poorly understood early ornithischian dinosaurs with extensive geographic and stratigraphic ranges. The group is best known from the Lower Jurassic upper ‘Stormberg Group’ (upper Elliot and Clarens formations) of southern Africa, previously represented by at least three distinct species and ten described specimens. This paper describes four additional heterodontosaurid specimens from southern Africa. A partial skull of a large individual of Heterodontosaurus tucki (NM QR 1788) is approximately 70 longer than that of the type specimen of Heterodontosaurus, and provides new information on allometric changes in mandibular morphology during growth in this taxon. It is the largest known heterodontosaurid cranial specimen, representing an individual approximately 1·75 metres in length, and perhaps 10 kg in body mass. NHMUK R14161 is a partial skull that appears to differ from all other heterodontosaurids on the basis of the proportions of the dentaries, and may represent an unnamed new taxon. Two additional partial skulls (NHMUK RU C68, NHMUK RU69) are referred to cf. Lycorhinus. At least four, and possibly five or more, heterodontosaurid species are present in the upper ‘Stormberg’. This high diversity may have been achieved by dietary niche partitioning, and suggests an adaptive radiation of small-bodied ornithischians following the end Triassic extinctions.
A new dicynodont–archosaur assemblage from the Late Triassic (Carnian) of Poland
Authors: Sulej Tomasz , Bronowicz Robert , Tałanda Mateusz , Niedźwiedzki Grzegorz 
Published: May 2011

ABSTRACTThis paper reports a new assemblage from the Late Triassic (mid–late Carnian) at Woźniki near Częstochowa (Poland). The Woźniki vertebrate assemblage is similar to that of Lisowice–Lipie Śląskie, a new locality bearing vertebrates from latest Triassic (latest Norian–early Rhaetian) strata of southern Poland, in the presence of dicynodonts, shark spines, plagiosaurs and a cyclotosaur, but conchostracans and bivalves are similar to those from the Krasiejów site (late Carnian). The most complete specimen from Woźniki belongs to a dicynodont, and consists of cranial and postcranial bones of a single individual. It demonstrates that large dicynodonts were part of the Late Triassic vertebrate assemblage in Central Europe. Numerous tetrapod tracks and traces are associated with skeletal fossils at Woźniki.
Role of design complexity in technology improvement
Authors: McNerney James , Farmer J. Doyne , Redner Sidney , Trancik Jessika E. 
Published: May 2011

We study a simple model for the evolution of the cost (or more generally the performance) of a technology or production process. The technology can be decomposed into
n
components, each of which interacts with a cluster of
d
- 1 other components. Innovation occurs through a series of trial-and-error events, each of which consists of randomly changing the cost of each component in a cluster, and accepting the changes only if the total cost of the cluster is lowered. We show that the relationship between the cost of the whole technology and the number of innovation attempts is asymptotically a power law, matching the functional form often observed for empirical data. The exponent α of the power law depends on the intrinsic difficulty of finding better components, and on what we term the design complexity: the more complex the design, the slower the rate of improvement. Letting
d
as defined above be the connectivity, in the special case in which the connectivity is constant, the design complexity is simply the connectivity. When the connectivity varies, bottlenecks can arise in which a few components limit progress. In this case the design complexity depends on the details of the design. The number of bottlenecks also determines whether progress is steady, or whether there are periods of stasis punctuated by occasional large changes. Our model connects the engineering properties of a design to historical studies of technology improvement.
Impacts of a recent storm surge on an Arctic delta ecosystem examined in the context of the last millennium
Authors: Pisaric Michael F. J. , Thienpont Joshua R. , Kokelj Steven V. , Nesbitt Holly , Lantz Trevor C. , Solomon Steven , Smol John P. 
Published: May 2011

One of the most ominous predictions related to recent climatic warming is that low-lying coastal environments will be inundated by higher sea levels. The threat is especially acute in polar regions because reductions in extent and duration of sea ice cover increase the risk of storm surge occurrence. The Mackenzie Delta of northwest Canada is an ecologically significant ecosystem adapted to freshwater flooding during spring breakup. Marine storm surges during the open-water season, which move saltwater into the delta, can have major impacts on terrestrial and aquatic systems. We examined growth rings of alder shrubs (
Alnus viridis
subsp.
fruticosa
) and diatoms preserved in dated lake sediment cores to show that a recent marine storm surge in 1999 caused widespread ecological changes across a broad extent of the outer Mackenzie Delta. For example, diatom assemblages record a striking shift from freshwater to brackish species following the inundation event. What is of particular significance is that the magnitude of this recent ecological impact is unmatched over the > 1,000-year history of this lake ecosystem. We infer that no biological recovery has occurred in this lake, while large areas of terrestrial vegetation remain dramatically altered over a decade later, suggesting that these systems may be on a new ecological trajectory. As climate continues to warm and sea ice declines, similar changes will likely be repeated in other coastal areas of the circumpolar Arctic. Given the magnitude of ecological changes recorded in this study, such impacts may prove to be long lasting or possibly irreversible.
Agonist trapped in ATP-binding sites of the P2X2 receptor
Authors: Jiang Ruotian , Lemoine Damien , Martz Adeline , Taly Antoine , Gonin Sophie , Prado de Carvalho Lia , Specht Alexandre , Grutter Thomas 
Published: May 2011

ATP-gated P2X receptors are trimeric ion channels, as recently confirmed by X-ray crystallography. However, the structure was solved without ATP and even though extracellular intersubunit cavities surrounded by conserved amino acid residues previously shown to be important for ATP function were proposed to house ATP, the localization of the ATP sites remains elusive. Here we localize the ATP-binding sites by creating, through a proximity-dependent “tethering” reaction, covalent bonds between a synthesized ATP-derived thiol-reactive P2X2 agonist (NCS-ATP) and single cysteine mutants engineered in the putative binding cavities of the P2X2 receptor. By combining whole-cell and single-channel recordings, we report that NCS-ATP covalently and specifically labels two previously unidentified positions N140 and L186 from two adjacent subunits separated by about 18 Å in a P2X2 closed state homology model, suggesting the existence of at least two binding modes. Tethering reaction at both positions primes subsequent agonist binding, yet with distinct functional consequences. Labeling of one position impedes subsequent ATP function, which results in inefficient gating, whereas tethering of the other position, although failing to produce gating by itself, enhances subsequent ATP function. Our results thus define a large and dynamic intersubunit ATP-binding pocket and suggest that receptors trapped in covalently agonist-bound states differ in their ability to gate the ion channel.
Agreement Between Patient‐ and Physician‐completed Pediatric Ulcerative Colitis Activity Index Scores
Authors: Lee Jessica J , Colman Ruben J , Mitchell Paul D , Atmadja Melissa L , Bousvaros Athos , Lightdale Jenifer R 
Published: May 2011

ABSTRACTObjectives:Currently validated ulcerative colitis (UC) activity measures are physician based, but incorporate patient reports of symptoms. We aimed to assess whether patient‐completed Pediatric UC Activity Index (PUCAI) scores are comparable to those of physician scores.Patients and Methods:We performed a single‐center prospective study to assess agreement between patient‐ and physician‐completed PUCAI scores. Seventy patients with UC (ages 4–29) representative of all of the disease activity categories (inactive, mild, moderate, and severe) in the currently published physician‐completed scoring system were recruited. Agreement was analyzed for PUCAI scores both as continuous and categorical measures. To ascertain validity, we compared both patient‐ and physician‐completed PUCAI scores with the physician global assessment and serum inflammatory markers.Results:Patient‐ and physician‐completed PUCAI summary scores were identical 49% of the time, were different but within the minimal clinically important difference (MCID) of 20 points 48% of the time, and were at or beyond the MCID only 3% of the time. In general, patients reported higher mean disease severity on their questionnaires than did their physicians, with a mean difference in PUCAI scores of 3 ± 8 (95% confidence interval 2%–5%). A categorical comparison of the 2 sets of questionnaires using the disease activity groups demonstrated perfect agreement for 60 (86%) pairs (kappa coefficient 0.78; 95% confidence interval 0.65%–0.90%). Both patient‐ and physician‐completed PUCAI scores also correlated well with the physician global assessment and serum inflammatory markers.Conclusions:Our data indicate strong agreement between PUCAI scores obtained directly from patients and those completed by physicians. Hence, a patient‐based PUCAI could complement existing instruments in both clinical and research settings.
Use of Fluoroscopy to Study In Vivo Motility in Mouse Pups
Authors: Williams Kent , Koyama Tatsuki , Schulz Daryl , Kaluza Grzegorz L , Pautler Robia G , Weisbrodt Norman , Conner Margaret E 
Published: May 2011

ABSTRACTObjectives:Few methods exist to noninvasively study in vivo gastrointestinal motility in animal models of enteric infections. None have been used on mouse pups, which often display more severe symptoms during enteric infections than adult mice. This study sought to determine whether digital fluoroscopy could be used to evaluate gastrointestinal motility in mouse pups as well as adult mice.Materials and Methods:Fluoroscopic imaging studies were performed on normal 6‐ to 8‐week‐old adult mice and 12‐day‐old pups to develop protocols for evaluating gastric and intestinal wall movements and changes in stomach sizes. These protocols were then applied to evaluate motility in an established rotavirus mouse model. Imaging studies were performed on adult mice at 0, 2, and 4 days postinfection and on 12‐day‐old pups at 2 days postinfection.Results:Fluoroscopic studies revealed postnatal differences of gastric peristalsis and rates of intestinal contractions between normal mouse pups and adult mice. Studies of the rotavirus mouse model revealed that differences in gastric function occur between rotavirus‐infected and control mouse pups, but no discernible difference occurs between infected and control adult mice. In contrast, there were no detectable differences in rates of intestinal wall movements between control pups with normal stools and infected pups with loose stools.Conclusions:These results demonstrate that fluoroscopy can evaluate in vivo motility in mouse pups and by doing so provide findings that are clinically relevant to the study of enteric infections in young.
Physiological and Bifidogenic Effects of Prebiotic Supplements in Infant Formulae
Authors: Veereman‐Wauters G , Staelens S , Van de Broek H , Plaskie K , Wesling F , Roger LC , McCartney AL , Assam P 
Published: May 2011

ABSTRACTObjectives:This randomized controlled trial involving 110 healthy neonates studied physiological and bifidogenic effects of galactooligosaccharides (GOS), oligofructose, and long‐chain inulin (fructooligosaccharides, FOS) in formula.Methods:Subjects were randomized to Orafti Synergy1 (50 oligofructose:50 FOS) 0.4 g/dL or 0.8 g/dL, GOS:FOS (90:10) 0.8 g/dL, or a standard formula according to Good Clinical Practice guidelines. A breast‐fed group was included for comparison. Outcome parameters were weight, length, intake, stool characteristics, crying, regurgitation, vomiting, adverse events, and fecal bacterial population counts. Statistical analyses used nonparametric tests.Results:During the first month of life, weight, length, intake, and crying increased significantly in all of the groups. Regurgitation and vomiting scores were low and similar. Stool frequency decreased significantly and similarly in all of the formula groups but was lower than in the breast‐fed group. All of the prebiotic groups maintained soft stools, only slightly harder than those of breast‐fed infants. The standard group had significantly harder stools at weeks 2 and 4 compared with 1 (P < 0.001 and P = 0.0279). The total number of fecal bacteria increased in all of the prebiotic groups (9.82, 9.73, and 9.91 to 10.34, 10.38, and 10.37, respectively, log10 cells/g feces, P = 0.2298) and more closely resembled the breast‐fed pattern. Numbers of lactic acid bacteria, bacteroides, and clostridia were comparable. In the SYN1 0.8 g/dL and GOS:FOS groups, Bifidobacterium counts were significantly higher at D14 and 28 compared with D3 and were comparable with the breast‐fed group. Tolerance and growth were normal.Conclusions:Stool consistency and bacterial composition of infants taking SYN1 0.8 g/dL or GOS:FOS–supplemented formula were closer to the breast‐fed pattern. There was no risk of dehydration.
Immunogenicity of Hepatitis A Vaccine in Children With Celiac Disease
Authors: Sari Sinan , Dalgic Buket , Basturk Bilkay , Gonen Sevim , Soylemezoglu Oguz 
Published: May 2011

ABSTRACTObjectives:The response to hepatitis A vaccine has not been studied in children with celiac disease (CD). The aim of the present study was to evaluate the immunogenicity of an inactivated hepatitis A virus (HAV) vaccine and the effect of the human leukocyte antigen (HLA) type on immunogenicity in children with CD.Patients and Methods:Thirty‐three patients with CD and 62 healthy controls were enrolled in the study. Inactivated HAV vaccine (Havrix; GlaxoSmithKline Biologicals, Rixensart, Belgium) containing 720 enzyme‐linked immunosorbent assay units of alum‐adsorbed hepatitis A antigen was administered intramuscularly in a 2‐dose schedule at 0 and 6 months. Seroconversion rates and antibody titers of HAV were measured at 1 and 7 months.Results:At 1 month, seroconversion rates were 78.8% and 77.4% and geometric mean titers were 50.7 and 49.9 mIU/mL in the CD and control groups, respectively (P > 0.05). At 7 months, seroconversion rates were 97% and 98.4% and geometric mean titers were 138.5 and 133 mIU/mL in the CD and control groups, respectively (P > 0.05). The most frequent HLA types were HLA‐DQ2, ‐DR3, and ‐DR7 alleles in patients with CD and HLA‐DQ3, ‐DQ6, ‐DR11, and ‐DR14 in the controls. There was no association between HLA alleles and antibody titers of hepatitis A vaccine.Conclusion:Children with CD have a good immune response to hepatitis A vaccine, similar to healthy controls.
Inside the microcluster: antigen receptor signalling viewed with molecular imaging tools
Authors: Tolar Pavel 
Published: May 2011

SummaryOver the last decade, live cell imaging has revealed the surprisingly complex orchestration of antigen receptor signalling at the immunological synapse. The imaging studies showed that one of the earliest steps in antigen receptor activation is the formation of submicroscopic clusters, which regulate the early signalling events. However, the molecular mechanisms operating inside these microclusters have remained beyond the resolution of optical microscopy. Recent development of imaging techniques that approach molecular resolution in intact cells offers a first view of the molecular processes inside these structures. Here I review the contributions of molecular imaging of the immunological synapse to our understanding of antigen receptor clustering, binding to antigens, and recruitment of signalling molecules. Finally, I provide an outlook on the future prospects of this rapidly advancing technology.
Signature of selection on the rhodopsin gene in the marine radiation of American seven‐spined gobies (Gobiidae, Gobiosomatini)
Authors: LARMUSEAU M. H. D. , VANHOVE M. P. M. , HUYSE T. , VOLCKAERT F. A. M. , DECORTE R. 
Published: May 2011

AbstractIn comparison with terrestrial and freshwater ecosystems, information about speciation modes and the role of selection in marine environments is scarce. Recent studies have indicated that spectral adaptation could play an important role in the diversification of marine species flocks. Natural selection influences specific amino acids (AAs) that are involved in the spectral tuning mechanism of visual pigment genes. To study the wider occurrence and the characteristics of spectral adaptation in marine radiations, a reinterpretation of the rhodopsin (RH1) data of American seven‐spined gobies (genus Elacatinus; Gobiidae; Teleostei) was carried out. Reanalysis revealed that some AAs, which are well known in the literature as spectral tuning sites, are variable in Elacatinus. Those crucial AA substitutions originated polyphyletically, indicating convergent evolution within the genus Elacatinus. Moreover, statistical tests based on the dN/dS ratio detected selection in several phylogenetic lineages and at specific AAs. Many of these AAs were previously shown to be under selection in other marine radiations. Therefore, the current phylogenetic approach provided an extended list of AAs that are probably involved in spectral tuning, and which should be validated by mutagenic experiments.
Distinct modes of adventitious rooting in Arabidopsis thaliana
Authors: da Rocha Correa L. , Troleis J. , Mastroberti A. A. , Mariath J. E. A. , Fett‐Neto A. G. 
Published: May 2011

AbstractThe literature describes different rooting protocols for Arabidopsis thaliana as models to study adventitious rooting, and results are generally perceived as comparable. However, there is a lack of investigations focusing on the distinct features, advantages and limitations of each method in the study of adventitious rooting with both wild‐type (WT) ecotypes and their respective mutants. This investigation was undertaken to evaluate the adventitious rooting process in three different experimental systems, all using A. thaliana, analysing the same rooting parameters after transient exposure to auxin (indole‐3‐acetic acid) and control conditions: excised leaves, de‐rooted plants and etiolated seedlings. The founding tissues and sites of origin of roots differed depending on the system used, whereas all rooting patterns were of the direct type (i.e., without callus formation). None of the systems had an absolute requirement for exogenous auxin, although rooting was enhanced by this phytohormone, with the exception of de‐rooted plants, which had adventitious rooting strongly inhibited by exogenous auxin. Root elongation was much favoured in isolated leaves. Auxin‐overproducing mutants could not be used in the detached leaf system due to precocious senescence; in the de‐rooted plant system, these mutants had a WT‐like rooting response, whereas the expression of the ‘rooty’ phenotype was only evident in the etiolated seedling system. Adventitious rooting of etiolated WT seedlings in the presence of exogenous auxin was inhibited by exogenous flavonoids, which act as auxin transport inhibitors; surprisingly, the flavonoid‐deficient mutant chs had a lower rooting response compared to WT. Although Arabidopsis is an excellent model system to study adventitious rooting, physiological and developmental responses differed significantly, underlining the importance of avoiding data generalisation on rooting responses derived from different experimental systems with this species.
Floral ontogeny of Ruteae (Rutaceae) and its systematic implications
Authors: Wei L. , Wang Y.‐Z. , Li Z.‐Y. 
Published: May 2011

AbstractFloral development was investigated in Ruta graveolens and Psilopeganum sinense, representing two genera in the tribe Ruteae. Special attention was paid to the sequence of initiation of organ whorls in the androecium and gynoecium. The antepetalous stamens arise at the same level as the antesepalous stamens in both species. The carpels are antepetalous in both taxa, indicating the androecium in both genera is obdiplostemonous. Compared with floral ontogeny of the ancestral genus Phellodendron (Toddalioideae), the obdiplostemonous androecium is a derived condition. The floral apex in P. sinense is quadrangular before initiation of the two carpels. Additionally, there are four dorsal and four ventral traces in the ovary. Integrated morphological and anatomical evidence indicates that the bicarpellate gynoecium in Psilopeganum most likely evolved from a tetracarpellate ancestor. Considering the similarities in morphological, geographical and chromosomal features, the ancestor may be Ruta‐like. Further molecular phylogenetic and genetic studies are needed to verify this assumption.