bluuebunny/crossref_metadata_2025 huggingface dataset:
Allometric Scaling and Resource Limitations Model of Tree Heights: Part 2. Site Based Testing of the Model
Authors: Choi Sungho , Ni Xiliang , Shi Yuli , Ganguly Sangram , Zhang Gong , Duong Hieu , Lefsky Michael , Simard Marc , Saatchi Sassan , Lee Shihyan , Ni-Meister Wenge , Piao Shilong , Cao Chunxiang , Nemani Ramakrishna , Myneni Ranga
Published: January 2013

The ultimate goal of this multi-article series is to develop a methodology to generate continuous fields of tree height and biomass. The first paper demonstrated the need for Allometric Scaling and Resource Limitation (ASRL) model optimization and its ability to generate spatially continuous fields of tree heights over the continental USA at coarse (1 km) spatial resolution. The objective of this second paper is to provide an assessment of that approach at site scale, specifically at 12 FLUXNET sites where more accurate data are available. Estimates of tree heights from the Geoscience Laser Altimeter System (GLAS) waveform data are used for model optimization. Amongst the five possible GLAS metrics that are representative of tree heights, the best metric is selected based on how closely the metric resembles field-measured and Laser Vegetation Imaging Sensor tree heights. In the optimization process, three parameters of the ASRL model (area of single leaf, α; exponent for canopy radius, η; and root absorption efficiency, γ) are simultaneously adjusted to minimize the difference between model predictions and observations at the study sites (distances to valid GLAS footprints ≤ 10 km). Performance of the optimized ASRL model was evaluated through comparisons to the best GLAS metric of tree height using a two-fold cross validation approach (R2 = 0.85; RMSE = 1.81 m) and a bootstrapping approach (R2 = 0.66; RMSE = 2.60 m). The optimized model satisfactorily performed at the site scale, thus corroborating results presented in part one of this series. Future investigations will focus on generalizing these results and extending the model formulation using similar allometric concepts for the estimation of woody biomass.
STOCK SPLITS AND LIQUIDITY FOR TWO MAJOR CAPITAL MARKETS FROM CENTRAL–EASTERN EUROPE
Authors: Rudnicki Józef
Published: January 2013

In the stock market there occur some events that contradict the efficient market hypothesis therefore they are called anomalies. One of the mysterious corporate events which has attracted the attention of numerous researchers is a stock split. I perform the review of implications of splitting the stock for market liquidity of companies listed on the Warsaw Stock Exchange and the Vienna Stock Exchange. I use event study, in particular Market model method and Market adjusted return method, to inspect the behavior of abnormal changes in daily trading volume for stock splits performed between 2000 through 2011 over a short run and assuming a longer time interval. Moreover, I juxtapose the results for both stock exchanges to examine whether the stock split phenomenon for two major capital markets from this part of Europe can be better explained by means of existing theories on stock splits. The research is aimed at analyzing the implications of the split for market liquidity, i.e. whether there occurs an immediate effect following the split as well as whether this corporate event improves the level of market liquidity over long run. Furthermore, the goal of the paper is to investigate whether the investors can cash in on the stock split, more specifically, whether they can profit from lower transaction costs. I document a significant growth in the market liquidity of stock splitting firms over 36 months following the split for both capital markets what is indicative of lower transaction costs for investors. The 1–percent significant results are consistent with the liquidity hypothesis on stock splits.
BANK LIQUIDITY RISK: ANALYSIS AND ESTIMATES
Authors: Jasienė Meilė , Martinavičius Jonas , Jasevičienė Filomena , Krivkienė Gražina
Published: January 2013

In today’s banking business, liquidity risk and its management are some of the most critical elements that underlie the stability and security of the bank’s operations, profit-making and clients confidence as well as many of the decisions that the bank makes. Managing liquidity risk in a commercial bank is not something new, yet scientific literature has not focused enough on different approaches to liquidity risk management and assessment. Furthermore, models, methodologies or policies of managing liquidity risk in a commercial bank have never been examined in detail either. The goal of this article is to analyse the liquidity risk of commercial banks as well as the possibilities of managing it and to build a liquidity risk management model for a commercial bank. The development, assessment and application of the commercial bank liquidity risk management was based on an analysis of scientific resources, a comparative analysis and mathematical calculations.
USING SOCIAL NETWORK AND DROPBOX IN BLENDED LEARNING: AN APPLICATION TO UNIVERSITY EDUCATION
Authors: Moreno Justo de Jorge
Published: January 2013

The main objective of this study is to analyze the use of the Social Networking and dropbox in blended learning by University students. We try identifying this method, over the student’s performance. The results show that the implementation of blended learning has a positive effect on in learning outcomes. The use of the Knowledge Management process has enabled captures a three-factor structure that reflected the five types of knowledge. The segmentation of the student sample analyzed using cluster technique, has established a clear typology of four groups. Students with higher levels of learning are related to the increased use of resources used and more proactive in blended learning.
BIOACCUMULATION OF LEAD IN BODY TISSUES OF ATLANTIC SALMON (SALMO SALAR L): EXPERIMENTAL INVESTIGATION AND COMPARATIVE ANALYSIS / ŠVINO BIOAKUMULIACIJOS ATLANTINIŲ LAŠIŠŲ (SALMO SALAR L.) KŪNO AUDINIUOSE EKSPERIMENTINIS TYRIMAS IR LYGINAMOJI ANALIZĖ
Authors: Idzelis Raimondas , Sauliutė Gintarė , Grigelevičiūtė Joana , Svecevičius Gintaras
Published: January 2013

The article presents tests on one-year artificially bred Atlantic salmon. For 14 days, fish were exposed to lead nitrate Pb (NO3)2 under concentration corresponding to the highest allowable standard of inland water making 0.005 mg Pb/l. Lead (Pb) in fish tissues (muscle and gills) was determined applying atomic absorption spectrophotometry (AAS). The obtained results have showed that the maximum-permissible-amount of lead in fish (MPA = 0.2 mg Pb/kg) (Lithuanian Hygiene Standard HN 54:2003) slightly exceeds in salmon gills (0.237 mg/kg), whereas in muscles, it exceeds more than twice (0.4 mg/kg). The received data have been compared with the results of the previous studies, where under the same experimental conditions, the bioaccumulation of lead in five types of fish, including roach, perch, rainbow trout, stone loach and gibel carp has been investigated. The conducted research has also revealed that different fish species quite differently accumulate lead while MPA has exceeded in the body tissues of a number of fish, i.e., in the majority of cases, it can be attributed to salmon and stone loach muscles and gills. When observing water bodies, the collected experimental data completely coincide with the results of studies on lead bioaccumulation in fish.

Santrauka

Bandymai buvo atliekami su dirbtinai veistų Atlantinių lašišų metinukais. 14 parų žuvys buvo veikiamos švino nitratu Pb(NO3)2 esant koncentracijai, atitinkančiai didžiausią leidžiamą koncentraciją paviršiniuose vandenyse (0,005 mg Pb/l). Švino (Pb) kiekis kūno audiniuose (raumenyse ir žiaunose) buvo nustatytas atominės absorbcijos spektrofotometriniu (AAS) būdu. Tyrimo rezultatai parodė, kad didžiausias leidžiamas švino kiekis žuvyje (DLK = 0,2 mg Pb/kg, Lietuvos higienos norma HN 54:2003) nežymiai buvo viršytas lašišos žiaunose (0,237 mg/kg), o raumenyse viršytas net 2 kartus (0,4 mg/kg). Gauti rezultatai buvo palyginti su ankstesniųjų metų tyrimų duomenimis, kur analogiškomis eksperimentinėmis sąlygomis buvo tirtos penkios žuvų rūšys: kuoja, ešerys, vaivorykštinis upėtakis, šlyžys bei sidabrinis karosas. Buvo nustatyta, kad skirtingos žuvų rūšys labai skirtingai kaupia šviną, o DLK buvo viršytas daugelio žuvų kūno audiniuose. Daugiausiai švino DLK buvo viršyta lašišos ir šlyžio raumenyse ir žiaunose. Eksperimentiniai duomenys sutampa su švino kaupimosi žuvyse iš stebimų vandens telkinių tyrimų duomenimis.
La représentation du village dans la revendication berbériste
Authors: Amrouche Nassim
Published: January 2013

Résumé En Algérie, le mouvement des aarch de 2001 s’inscrit dans la continuité du Printemps berbère d’avril 1980 à travers une organisation faisant référence au contexte tribal local, qui fut lui-même porté par le pouvoir colonial français. Cette revendication culturelle berbère met en scène une « culture » où le village imaginé tient une place fondamentale dans le militantisme urbain. En recréant, dans leur discours politique, des espaces ruraux et montagneux, les militants pensent un passé essentialisé dans sa pureté culturelle comme un outil d’opposition contemporaine.
Un Tour sur soi. Les bons usages de la nostalgie en compagnonnage
Authors: Adell Nicolas
Published: January 2013

Résumé Ce texte traite des usages et des représentations de la nostalgie au sein des sociétés compagnonniques. Celle-ci se déploie sur deux registres. Par-delà la nostalgie de la région d’origine, provoquée par le départ sur le Tour de France, on trouve une nostalgie du Tour lui-même que suscitent les compagnons. L’auteur montre que ce redoublement nostalgique fait des pratiques, discours et objets qui la construisent des ressorts puissants de la construction identitaire des individus.
Le bébé et les figurations corporelles présymboliques
Authors: Golse Bernard
Published: January 2013

Résumé Après avoir évoqué la question de la présence et de l’absence au regard de la psychanalyse et de la théorie de l’attachement, ce travail précise les deux grands systèmes de symbolisation en présence de l’objet (symbolisation primaire, surtout préverbale) et en absence de l’objet (symbolisation secondaire, surtout verbale). Pour conceptualiser le passage d’un système à l’autre, il semble nécessaire, aujourd’hui, de prendre en compte un gradient spatio-temporel de symbolisation qui fait une place à la question de l’écart, en deçà de l’absence.
Le présent des odeurs
Authors: Nakov Anastasia
Published: January 2013

Résumé La présence du corps dans le cadre psychanalytique s’affirme de différentes manières. Les odeurs « diffusées » par les patients n’ont pratiquement jamais retenu l’attention des psychanalystes. Hormis Didier Anzieu, qui consacre un chapitre à ce problème dans le Moi-Peau, cette question ne semble pas avoir fait l’objet d’une conceptualisation particulière. À l’aide d’exemples cliniques nous pouvons voir combien ces émanations archaïques du corps sont porteuses de sens et combien leur rôle est important dans notre élaboration contre-transférentielle. Les odeurs ont un rôle défensif contre les mouvements pulsionnels d’agressivité et d’angoisse de mort, ainsi que dans les manœuvres défensives complexes de séduction.
La lecture citationnelle ou l' ars legendi comme ars excerpendi
Authors: Minzetanu Andrei
Published: January 2013

Résumé Cet article s’intéresse à une méthode (appelée à la Renaissance, ars excerpendi ) et à un régime de lecture, à la fois très scolaire et très créatif, qui présuppose un prélèvement systématique de citations, un intérêt très significatif pour la Phrase, et des interférences avec d’autres régimes très similaires : la lecture consultation, la lecture « anthologisante » et l’« ego-surfing ». Si, dans ce cadre, l’écriture peut être envisagée comme une « science de la composition », la lecture y sera une « science de la décomposition », une décomposition en fleurs et fragments citables. Au sein de cette dialectique de la lecture et de l’écriture, le lettré « excerpteur » apprend l’art et la vocation citationnels, il apprend à faire des citations : des extraits de lecture et des fragments appelés à devenir des citations.
Going for Gold
Authors: Khan B. Zorina
Published: January 2013

Résumé Dans cet article, on se propose de comparer l’attribution de prix au système des brevets d’invention. Les données comprennent un échantillon de produits exposés et primés aux expositions de l’industrie organisées par la Massachusetts Charitable Mechanic Association, entre 1837 et 1874. Les résultats révèlent les facteurs qui ont conduit des auteurs d’inventions particulières soit à tenter de bénéficier de retours grâce aux droits de propriété intellectuelle, soit à chercher des institutions alternatives. Les lauréats de prix tendent à appartenir aux classes plus privilégiées que l’ensemble des détenteurs de brevets, comme on peut l’évaluer à partir de la fortune et du statut des inventeurs lors des expositions. De plus, l’octroi de prix est moins systématique que celui de brevets, et n’est pas lié à des critères de productivité de l’innovation comme le capital inventif ou le succès commercial de l’invention. JEL Code: N 71, O31, O 34
Are You Open?
Authors: Pénin Julien
Published: January 2013

Résumé Cet article s’interroge sur la signification et l’importance du concept d’ « ouverture » lorsqu’il est appliqué au processus de production de connaissances. Nous proposons deux définitions d’une innovation ou technologie ouverte : une forte et une faible. Le point commun entre les deux est qu’elles soulignent chacune l’importance des conditions d’accès à la connaissance produite : une connaissance est ouverte lorsqu’elle est rendue disponible à tous, sous des conditions à la fois non discrétionnaires et raisonnables. Notre définition permet ainsi de mettre en avant la différence entre ouverture et gratuité : une technologie peut être considérée comme ouverte même si elle est payante. De surcroît, cette définition permet également d’établir une distinction claire entre le concept d’innovation ouverte à la Chesbrough [2003], qui ne satisfait pas nos conditions d’ouverture, et les concepts d’invention collective (Allen [1983]; Nuvolari [2004]) et, plus généralement, de modèles de production de connaissances dits « open source », qui les satisfont. Nous terminons en discutant des implications managériales et politiques de notre recherche. JEL Code: O34
Spatio-temporal variability of inorganic and organic nutrients in five Galician rias (NW Spain)
Authors: Doval María Dolores , López Adela , Madriñán Milagros
Published: January 2013

The spatial variability of inorganic (nitrate, nitrite, ammonium, phosphate and silicate) and organic (dissolved organic carbon) nutrients in five Galician rias (Vigo, Pontevedra, Arousa, Muros and Ares-Betanzos) was assessed by considering average values for the upwelling and downwelling periods. Inner stations were significantly different from middle and outer stations, especially during the downwelling period. Spatial differences between the five rías, tested by means of a multivariate analysis, were found in both periods. The behaviour of inorganic and organic nutrient variables was also significantly different between periods with and without shellfish harvesting closures due to the occurrence of toxic phytoplankton species.
Interspecific variability of endocrine disruption and oxidative stress in two bivalve species from the Ria Formosa Lagoon (south coast of Portugal)
Authors: Pereira Catarina , Gomes Tânia , Cardoso Cátia , Almeida Ana Catarina , Araújo Olinda , Bebianno Maria João , Cravo Alexandra
Published: January 2013

Estuaries are highly productive ecosystems that have been increasingly affected by anthropogenic activities. In this study, the presence of endocrine disrupting compounds (EDCs) and their relation to oxidative stress were assessed in two bivalve species (mussels Mytilus galloprovincialis and clams Ruditapes decussatus) from the Ria Formosa Lagoon (south Portugal). We applied the alkali-labile phosphate (ALP) assay to determine vitellogenin-like protein levels, and the lipid peroxidation (LPO) method to assess oxidative damage. Mussels and clams exhibited the same pattern of ALP concentrations, with no differences between genders and higher levels in winter. R. decussatus showed higher ALP values than M. galloprovincialis, possibly associated with a stronger responsiveness of clams to EDCs or due to the influence of the reproductive cycle. Mussels exhibited a more evident seasonal effect for LPO, indicating that these organisms are more influenced by seasonal fluctuations in the water column compared to the sediment-associated clams. Both species appear to be under the influence of EDC exposure (which could induce Vg-like protein synthesis) and oxidative stressors (leading to lipid peroxidation) in the Ria Formosa Lagoon, particularly in winter, reflecting the presence of different contaminants in Ria Formosa and environmental changes, as well as complex interactions between them.
Evolution of lead concentrations in the Nervión Estuary, southeastern Bay of Biscay
Authors: Larreta Joana , Franco Javier , Valencia Victoriano
Published: January 2013

Over many years the Nervión estuary has received an intense lead input from various sources in relation to different human activities. This input has produced lead accumulation in some compartments of the estuarine system, which is mainly reflected in the sediments. In recent years, the closure and/or transformation of some contaminating industries, in addition to the implementation of a sewerage scheme, have considerably reduced these inputs into the system. The lead concentration in the sediments has shown a general decreasing trend since 1995. Although this trend is neither progressive nor statistically significant for all the studied stations, lead concentrations in surficial sediment are significantly lower in recent years than at the beginning of the study period. Regarding potential adverse effects on biota, although one third of the values measured during the study period are above concentrations associated with toxicity, in recent years very few values exceed these references. Time series of lead concentrations in biomonitors (mussels) do not show statistically significant temporal trends, and most of the values fulfil the quality objective proposed for this region.
Biomarkers in Nereis diversicolor (Polychaeta: Nereididae) as management tools for environmental assessment on the southwest Iberian coast
Authors: Gomes Tânia , Gonzalez-Rey Maria , Rodríguez-Romero Araceli , Trombini Chiara , Riba Immaculada , Blasco Julián , Bebianno Maria João
Published: January 2013

The environmental quality of the southwest Iberian coast was assessed in different areas (Ria Formosa Lagoon, Guadiana Estuary and Cádiz Bay) focusing on metal contamination (Cd, Cu, Ni, Pb and Zn) in Nereis diversicolor whole tissues. In addition, associated toxicological effects were assessed using a multibiomarker approach combining several conventional biomarkers. The set of biomarkers selected included antioxidant enzymes (catalase, superoxide dismutase and glutathione peroxidase), metallothionein and lipid peroxidation. N. diversicolor from the Ria Formosa Lagoon, Guadiana River and Cádiz Bay responded differently to metal contamination with different biomarker responses showing a clear site trend, suggesting different sources and/or magnitudes of contamination. Cadmium was a source of oxidative stress in polychaetes, mainly in Cádiz Bay, with a significant influence on antioxidant enzymes and enhancement of lipid peroxidation. The highest MT concentrations were in the Ria Formosa Lagoon and in the Guadiana River, where there was a direct relationship with high nickel concentrations. Biomarker responses of N. diversicolor are useful tools for environmental quality assessment on the southwest Iberian coast, and more specific metal biomarkers should be included in future assessments.
Synaptotagmin XI Regulates Phagocytosis and Cytokine Secretion in Macrophages
Authors: Arango Duque Guillermo , Fukuda Mitsunori , Descoteaux Albert
Published: January 2013

Synaptotagmins (Syts) are a group of type I membrane proteins that regulate vesicle docking and fusion in processes such as exocytosis and phagocytosis. All Syts possess a single transmembrane domain, and two conserved tandem Ca2+-binding C2 domains. However, Syts IV and XI possess a conserved serine in their C2A domain that precludes these Syts from binding Ca2+ and phospholipids, and from mediating vesicle fusion. Given the importance of vesicular trafficking in macrophages, we investigated the role of Syt XI in cytokine secretion and phagocytosis. We demonstrated that Syt XI is expressed in murine macrophages, localized in recycling endosomes, lysosomes, and recruited to phagosomes. Syt XI had a direct effect on phagocytosis and on the secretion of TNF and IL-6. Whereas small interfering RNA–mediated knockdown of Syt XI potentiated secretion of these cytokines and particle uptake, overexpression of an Syt XI construct suppressed these processes. In addition, Syt XI knockdown led to decreased recruitment of gp91phox and lysosomal-associated membrane protein–1 to phagosomes, suggesting attenuated microbicidal activity. Remarkably, knockdown of Syt XI ensued in enhanced bacterial survival. Our data reveal a novel role for Syt XI as a regulator of cytokine secretion, particle uptake, and macrophage microbicidal activity.
High-Affinity IgG Antibodies Develop Naturally in Ig-Knockout Rats Carrying Germline Human IgH/Igκ/Igλ Loci Bearing the Rat CH Region
Authors: Osborn Michael J. , Ma Biao , Avis Suzanne , Binnie Ashleigh , Dilley Jeanette , Yang Xi , Lindquist Kevin , Ménoret Séverine , Iscache Anne-Laure , Ouisse Laure-Hélène , Rajpal Arvind , Anegon Ignacio , Neuberger Michael S. , Buelow Roland , Brüggemann Marianne
Published: January 2013

Mice transgenic for human Ig loci are an invaluable resource for the production of human Abs. However, such mice often do not yield human mAbs as effectively as conventional mice yield mouse mAbs. Suboptimal efficacy in delivery of human Abs might reflect imperfect interaction between the human membrane IgH chains and the mouse cellular signaling machinery. To obviate this problem, in this study we generated a humanized rat strain (OmniRat) carrying a chimeric human/rat IgH locus (comprising 22 human VHs, all human D and JH segments in natural configuration linked to the rat CH locus) together with fully human IgL loci (12 Vκs linked to Jκ-Cκ and 16 Vλs linked to Jλ-Cλ). The endogenous Ig loci were silenced using designer zinc finger nucleases. Breeding to homozygosity resulted in a novel transgenic rat line exclusively producing chimeric Abs with human idiotypes. B cell recovery was indistinguishable from wild-type animals, and human V(D)J transcripts were highly diverse. Following immunization, the OmniRat strain performed as efficiently as did normal rats in yielding high-affinity serum IgG. mAbs, comprising fully human variable regions with subnanomolar Ag affinity and carrying extensive somatic mutations, are readily obtainable, similarly to conventional mAbs from normal rats.
Primary malignant melanoma of the vagina: A case report and review of literature
Authors: Chaudhuri Snehamay , Das Diptimay , Chowdhury Soham , Gupta Anjan Das
Published: January 2013

A 60 year old woman presented in gynecology department with bleeding per vagina and subsequently histotpathologically, it was diagnosed as malignant melanoma of the vagina. She underwent excision biopsy. On metastatic work-up, Positron emission tomography (PET) scan proved that she had distant metastasis and received palliative radiotherapy and chemotherapy, with temozolamide. She is alive after one year.
Identification and Insilico Analysis of Retinoblastoma Serum microRNA Profile and Gene Targets towards Prediction of Novel Serum Biomarkers
Authors: Beta Madhu , Venkatesan Nalini , Vasudevan Madavan , Vetrivel Umashankar , Khetan Vikas , Krishnakumar Subramanian
Published: January 2013

Retinoblastoma (RB) is a malignant tumor of the retina seen in children, and potential non invasive biomarkers are in need for rapid diagnosis and for prognosticating the therapy. This study was undertaken to identify the differentially expressed miRNAs in the serum of children with RB in comparison with the normal age matched serum, to analyze its concurrence with the existing RB tumor miRNA profile, to identify its novel gene targets specific to RB, and to study the expression of a few of the identified oncogenic miRNAs in the advanced stage primary RB patient's serum sample. MiRNA profiling was performed on 14 pooled serum from children with advanced RB and 14 normal age matched serum samples, wherein 21 miRNAs were found to be upregulated (fold change ≥ +2.0, P ≤ 0.05) and 24 to be downregulated (fold change ≤ –2.0, P ≤ 0.05). Furthermore, intersection of 59 significantly deregulated miRNAs identified from RB tumor profiles with that of miRNAs detected in serum profile revealed that 33 miRNAs had followed a similar deregulation pattern in RB serum. Later we validated a few of the miRNAs (miRNA 17-92) identified by microarray in the RB patient serum samples (n = 20) by using qRT-PCR. Expression of the oncogenic miRNAs, miR-17, miR-18a, and miR-20a by qRT-PCR was significant in the serum samples exploring the potential of serum miRNAs identification as noninvasive diagnosis. Moreover, from miRNA gene target prediction, key regulatory genes of cell proliferation, apoptosis, and positive and negative regulatory networks involved in RB progression were identified in the gene expression profile of RB tumors. Therefore, these identified miRNAs and their corresponding target genes could give insights on potential biomarkers and key events involved in the RB pathway.
The marine inorganic carbon system along the Gulf of Mexico and Atlantic coasts of the United States: Insights from a transregional coastal carbon study
Authors: Wang Zhaohui Aleck , Wanninkhof Rik , Cai Wei-Jun , Byrne Robert H. , Hu Xinping , Peng Tsung-Hung , Huang Wei-Jen
Published: January 2013

Distributions of total alkalinity (TA), dissolved inorganic carbon (DIC), and other parameters relevant to the marine inorganic carbon system were investigated in shelf and adjacent ocean waters during a U.S. Gulf of Mexico and East Coast Carbon cruise in July–August 2007. TA exhibited near‐conservative behavior with respect to salinity. Shelf concentrations were generally high in southern waters (Gulf of Mexico and East Florida) and decreased northward from Georgia to the Gulf of Maine. DIC was less variable geographically and exhibited strongly nonconservative behavior. As a result, the ratio of TA to DIC generally decreased northward. The spatial patterns of other CO2 system parameters closely followed those of the TA : DIC ratio. All sampled shelf waters were supersaturated with respect to aragonite (saturation state ΩA > 1). The most intensely buffered and supersaturated waters (ΩA > 5.0) were in northern Gulf of Mexico river‐plume waters; the least intensely buffered and least supersaturated waters (ΩA < 1.3) were in the deep Gulf of Maine. Due to their relatively low pH, ΩA, and buffer intensity, waters of the northeastern U.S. shelves may be more susceptible to acidification pressures than are their southern counterparts. In the Mid‐Atlantic Bight, alongshore mixing tended to increase DIC concentrations southward, but this effect was largely offset by the opposing effects of biogeochemical processing. In the Gulf of Mexico, downstream increases in Loop Current DIC suggested significant contributions from shelf and gulf waters, estimated at 9.1 × 109 mol C d−1. Off the southeastern U.S., along‐flow chemical changes in the Florida Current were dominated by mixing associated with North Atlantic subtropical recirculation.
Disentangling the origins of branched tetraether lipids and crenarchaeol in the lower Amazon River: Implications for GDGT‐based proxies
Authors: Zell Claudia , Kim Jung-Hyun , Moreira-Turcq Patricia , Abril Gwenaël , Hopmans Ellen C. , Bonnet Marie-Paule , Sobrinho Rodrigo Lima , Damsté Jaap S. Sinninghe
Published: January 2013

To trace the origin of branched glycerol dialkyl glycerol tetraethers (brGDGTs), their distribution in soils and suspended particulate matter (SPM) of Amazonian rivers and floodplain lakes (várzeas) was studied. Differences in distribution between river SPM and surrounding (lowland) soils suggests an additional brGDGT source to eroded soils in the lowland drainage basin. Erosion of high Andean soils (above 2500 m in altitude) has no major influence because its brGDGT distribution differs substantially from that in river SPM. Furthermore, SPM in the Tapajós River, a tributary that does not derive from the Andes, has a virtually identical brGDGT distribution to that of the Amazon main stem. The higher proportion of phospholipid‐derived brGDGTs in river SPM compared to soils indicates that in situ production in the Amazon is an additional source for riverine brGDGTs. This affects the methylation and cyclization index of brGDGTs (MBT‐CBT), resulting in slightly lower MBT‐CBT‐derived temperatures and slightly higher CBT‐derived pH values, i.e., between the pH of the basin soil and that of the river. Since the difference between MBT‐CBT‐derived temperatures of Amazon River SPM and the surrounding soils is relatively small (2°C) compared to other aquatic systems (for lakes a difference of ∼ 10°C has been observed), it might still be possible to trace large climate changes in the Amazon basin with the MBT‐CBT using river fan cores. However, variations in in situ production of brGDGTs in the Amazon River over time and space have to be evaluated in the future. Likewise, in situ production may affect the application of the MBT‐CBT paleothermometer in other river systems. Our results also show that crenarchaeol is primarily produced in the Amazon River and that its varying production influences the branched vs. isoprenoid tetraether (BIT) index. This indicates that the BIT index not only represents the input of soil organic carbon to the river but is also affected by in situ production of brGDGTs and crenarchaeol.
The responses of eight coral reef calcifiers to increasing partial pressure of CO2 do not exhibit a tipping point
Authors: Comeau S. , Edmunds P. J. , Spindel N. B. , Carpenter R. C.
Published: January 2013

The objective of this study was to investigate whether a tipping point exists in the calcification responses of coral reef calcifiers to CO2. We compared the effects of six partial pressures of CO2 (PCO2) from 28 Pa to 210 Pa on the net calcification of four corals (Acropora pulchra, Porites rus, Pocillopora damicornis, and Pavona cactus), and four calcified algae (Hydrolithon onkodes, Lithophyllum flavescens, Halimeda macroloba, and Halimeda minima). After 2 weeks of acclimation in a common environment, organisms were incubated in 12 aquaria for 2 weeks at the targeted PCO2 levels and net calcification was quantified. All eight species calcified at the highest PCO2 in which the calcium carbonate aragonite saturation state was ∼1. Calcification decreased linearly as a function of increasing partial PCO2 in three corals and three algae. Overall, the decrease in net calcification as a function of decreasing pH was ∼10% when ambient PCO2 (39 Pa) was doubled. The calcification responses of P. damicornis and H. macroloba were unaffected by increasing PCO2. These results are inconsistent with the notion that coral reefs will be affected by rising PCO2 in a response characterized by a tipping point. Instead, our findings combined among taxa suggest a gradual decline in calcification will occur, but this general response includes specific cases of complete resistance to rising PCO2. Together our results suggest that the overall response of coral reef communities to ocean acidification will be monotonic and inversely proportional to PCO2, with reef‐wide responses dependent on the species composition of calcifying taxa.
Examining shifts in zooplankton community variability following biological invasion
Authors: Mines Conor H. , Ghadouani Anas , Legendre Pierre , Yan Norman D. , Ivey Gregory N.
Published: January 2013

We examined 20 yr of zooplankton samples from Harp Lake for shifts in zooplankton variability following invasion by zooplankton predator Bythotrephes longimanus, using organism body size—as measured at high resolution by Laser Optical Plankton Counter (LOPC)—as the primary metric of investigation. A period of transitory high variability in the 2 yr post‐invasion was observed for both body size compositional variability and aggregate variability metrics, with both measures of variability shifting from low or intermediate to high variability immediately following invasion, before shifting again to intermediate variability ∼ 2 yr post‐invasion. Aggregate and compositional variability dynamics were also considered in combination over the study period, revealing that the period of transitory high variability coincided with a shift from a community‐wide stasis variability pattern to one of asynchrony, before a shift back to stasis 2 yr post‐invasion. These dynamics were related to changes in the significant zooplankton species within the Harp Lake community over the pre‐ and post‐invasion periods, and are likely to be indicative of changes in the stability in the zooplankton community following invasion by Bythotrephes. The dual consideration of aggregate and compositional variability as measured by LOPC was found to provide a valuable means to assess the ecological effects of biological invasion on zooplankton communities as a whole, extending our knowledge of the effects of invasion beyond that already revealed through more traditional taxonomic investigation.
An in vivo Study Comparing the Characteristics of Esthetic, Self-ligating and Metallic Brackets
Authors: Mhatre Amol , Deshpande Ashwin , Doshi Sachin S , Gaikwad Shashank Sharad
Published: January 2013

The aim of thisin vivostudy was to compare the characteristics of esthetic, self-ligating brackets (SLBs) and metallic brackets, to find bracket bond failures with SLBs and manually ligating brackets (MLBs), bracket breakages with SLBs and MLBs and staining with the SLBs. Seven patients were compared in each group. Standard light curing bonding methods were used in both the groups. Chairside time saving, appliance efficiency and bracket bond failures were compared among the groups whereas staining was observed with the SLBs. Appliance efficiency was evaluated by peer assessment rating (PAR) scores. Results showed significant chairside time being saved in SLBs, whereas the appliance efficiency was not significant. Bond failures were found only in SLBs as well as breakages along with staining. Henceforth, we could conclude that though SLBs had advantage of saving chairside time but also had disadvantage of losing more time with bond failures.

Materials and Methods

Two groups of seven patients were created: First group (seven patients) received treatment with OPAL SLBs (Ultradent products, USA) and second group (seven patients) received treatment with MLBs manually ligating metal brackets (Nu-Edge, TP Orthodontics, USA). Case selection was done for both the groups. Bonding procedure was done in both groups in which primer application was done on both tooth surface and bracket base in case of OPAL SLB's while in case of MLBs, primer was applied only on tooth surface. A questionnaire was evaluated for knowing patients comfort.

Results

Comparison of mean values of PAR scores in both the groups for pre-, post-treatment and in the reduction of PAR scores was done.

It showed that SLBs were 6.5 times quicker than the MLBs during the archwire changes, thus saving considerable chairside time. Treatment outcome after 120 days, in both groups was almost the same. The SLBs had many bracket bond failures while MLBs had none. SLBs had other shortcomings, such as bracket breakage, staining, cap opening, etc.

How to cite this article

Gaikwad SS, Deshpande A, Doshi SS, Mhatre A, Sonawane M. Anin vivoStudy Comparing the Characteristics of Esthetic, Self-ligating and Metallic Brackets. J Contemp Dent 2012;2(3):73-77.
Cone Beam Computed Tomography: Adding the Third Dimension
Authors: Gadda Rohit B , Salvi Rohini , Patil Neha Anil
Published: January 2013

Cone beam computed tomography is a comparatively new threedimensional imaging technology, which has been specially developed for imaging of the maxillofacial complex. The aim of this paper is to accustom the dental fraternity with the wide and potential applications of cone beam computed tomography in dentistry.

How to cite this article

Patil NA, Gadda R, Salvi R. Cone Beam Computed Tomography: Adding the Third Dimension. J Contemp Dent 2012;2(3):84-88
Retreatment of Silver Point Obturation: A Case Report and an Overview
Authors: Shenoy Vanitha , Gulati Shikha
Published: January 2013

Clinicians frequently encounter endodontically treated teeth that contain silver points within their roots. If endodontic treatment is failing, the need arises to remove this metallic obstruction to facilitate successful nonsurgical retreatment. For the retrieval of these obstructions, most of the methods suggest creating and enlarging a space around the obstruction to loosen it before its retrieval. A large number of removal techniques exists including use of a variety of appropriate burs, specialized forceps, ultrasonic instruments in direct or indirect contact, peripheral filing techniques in the presence of solvents, chelators, or irrigants and microtube delivery using mechanical, adhesion techniques. This case report involves the use of several Hedstrom files, inserted and twisted along the length of silver point to entangle the point and withdraw it, with an overview of other techniques of removal of silver point.

How to cite this article

Gulati S, Sumanthini MV, Shenoy V. Retreatment of Silver Point Obturation: A Case Report and an Overview. J Contemp Dent 2012;2(3):114-118.
Fluorescent biological aerosol particles measured with the Waveband Integrated Bioaerosol Sensor WIBS-4: laboratory tests combined with a one year field study
Authors: Toprak E. , Schnaiter M.
Published: January 2013

Abstract. In this paper bioaerosol measurements conducted with the Waveband Integrated Bioaerosol Sensor mark 4 (WIBS-4) are presented. The measurements comprise aerosol chamber characterization experiments and a one-year ambient measurement period at a semi-rural site in South Western Germany. This study aims to investigate the sensitivity of WIBS-4 to biological and non-biological aerosols and detection of biological particles in the ambient aerosol. Several types of biological and non-biological aerosol samples, including fungal spores, bacteria, mineral dust, ammonium sulphate, combustion soot, and fluorescent polystyrene spheres, were analyzed by WIBS-4 in the laboratory. The results confirm the sensitivity of the ultraviolet light-induced fluorescence (UV-LIF) method to biological fluorophores and show the good discrimination capabilities of the two excitation wavelengths/detection wavebands method applied in WIBS-4. However, a weak cross-sensitivity to non-biological fluorescent interferers remains and is discussed in this paper. All the laboratory studies have been undertaken in order to prepare WIBS-4 for ambient aerosol measurements. According to the one-year ambient aerosol study, number concentration of fluorescent biological aerosol particles (FBAP) show strong seasonal and diurnal variability. The highest number concentration of FBAP was measured during the summer term and decreased towards the winter period when colder and drier conditions prevail. Diurnal FBAP concentrations start to increase after sunset and reach maximum values during the late night and early morning hours. On the other hand, the total aerosol number concentration was almost always higher during daytime than during nighttime and a sharp decrease after sunset was observed. There was no correlation observed between the FBAP concentration and the meteorological parameters temperature, precipitation, wind direction and wind speed. However, a clear correlation was identified between the FBAP number concentration and the relative humidity. Humidity-controlled release mechanisms of some fungal spore species are discussed as a possible explanation.
Extreme winds over Europe in the ENSEMBLES regional climate models
Authors: Outten S. D. , Esau I.
Published: January 2013

Abstract. Extreme winds cause vast amounts of damage every year and represent a major concern for numerous industries including construction, afforestation, wind energy and many others. Under a changing climate, the intensity and frequency of extreme events are expected to change, and accurate predictions of these changes will be invaluable to decision makers and society as a whole. This work examines four regional climate model downscalings over Europe from the "ENSEMBLE-based Predictions of Climate Changes and their Impacts" project (ENSEMBLES), and investigates the predicted changes in the 50 yr return wind speeds and the associated uncertainties. This is accomplished by employing the peaks-over-threshold method with the use of the Generalised Pareto Distribution. The models show that for much of Europe the 50 yr return wind is projected to change by less than 2 m s−1, while the uncertainties associated with the statistical estimates are larger than this. In keeping with previous works in this field, the largest source of uncertainty is found to be the inter-model spread, with some locations showing differences in the 50 yr return wind of over 20 m s−1 between two different downscalings.
Profiling tropospheric CO2 using Aura TES and TCCON instruments
Authors: Kuai L. , Worden J. , Kulawik S. , Bowman K. , Lee M. , Biraud S. C. , Abshire J. B. , Wofsy S. C. , Natraj V. , Frankenberg C. , Wunch D. , Connor B. , Miller C. , Roehl C. , Shia R.-L. , Yung Y.
Published: January 2013

Abstract. Monitoring the global distribution and long-term variations of CO2 sources and sinks is required for characterizing the global carbon budget. Total column measurements are useful for estimating regional-scale fluxes; however, model transport remains a significant error source, particularly for quantifying local sources and sinks. To improve the capability of estimating regional fluxes, we estimate lower tropospheric CO2 concentrations from ground-based near-infrared (NIR) measurements with space-based thermal infrared (TIR) measurements. The NIR measurements are obtained from the Total Carbon Column Observing Network (TCCON) of solar measurements, which provide an estimate of the total CO2 column amount. Estimates of tropospheric CO2 that are co-located with TCCON are obtained by assimilating Tropospheric Emission Spectrometer (TES) free tropospheric CO2 estimates into the GEOS-Chem model. We find that quantifying lower tropospheric CO2 by subtracting free tropospheric CO2 estimates from total column estimates is a linear problem, because the calculated random uncertainties in total column and lower tropospheric estimates are consistent with actual uncertainties as compared to aircraft data. For the total column estimates, the random uncertainty is about 0.55 ppm with a bias of −5.66 ppm, consistent with previously published results. After accounting for the total column bias, the bias in the lower tropospheric CO2 estimates is 0.26 ppm with a precision (one standard deviation) of 1.02 ppm. This precision is sufficient for capturing the winter to summer variability of approximately 12 ppm in the lower troposphere; double the variability of the total column. This work shows that a combination of NIR and TIR measurements can profile CO2 with the precision and accuracy needed to quantify lower tropospheric CO2 variability.
Downward fluxes of sinking particulate matter in the deep Ionian Sea (NESTOR site), Eastern Mediterranean: seasonal and interranual variability
Authors: Stavrakakis S. , Gogou A. , Krasakopoulou E. , Karageorgis A. P. , Kontoyiannis H. , Rousakis G. , Velaoras D. , Perivoliotis L. , Kambouri G. , Stavrakaki I. , Lykousis V.
Published: January 2013

Abstract. In order to assess seasonal and interranual variability in the export of particulate matter and its main constituents, sediment traps were deployed at five successive depths from February 2006 to March 2010 in the deepest basin of the Mediterranean (SE Ionian Sea, NESTOR site). The average total mass fluxes were 66, 58, 54, 34, and 52 mg m−2 d−1, at 700, 1200, 2000, 3200, and 4300 m, respectively. The interranual variability generally witnesses a gradual increase of fluxes during the experiment. The temporal variations of the mass flux showed similar seasonal signal at all sampling depths with higher values in spring–summer and lower in autumn–winter. Changes in the main constituents of the mass flux (organic carbon, carbonates, opal, and lithogenic matter) largely followed the same temporal variability with mass flux, revealing mechanisms of rapid vertical (top-down) transport from 700 m down to 4300 m-depth. Lateral inputs at the deepest trap are probably of importance, attributed to the influence of the deep Adriatic water, characterized by relatively higher turbidity than overlying water masses. The Ionian Sea displays high seasonal variability with maximum productivity rates observed during the late winter/spring convective mixing period. Our flux study proposes two additional processes, potentially of high importance for fuelling surface waters with nutrients at the NESTOR site: (1) the upwelling of intermediate waters in late spring-early summer, causing nutrient inputs in the surface layer which may lead to episodes of increased productivity, as witnessed by the organic carbon, carbonate, and opal fluxes in the mesopelagic and bathypelagic layers and (2) the influence of episodic dust input events, leading to enhanced fluxes of lithogenic matter.
Mesospheric CO above Troll station, Antarctica observed by a ground based microwave radiometer
Authors: Straub C. , Espy P. J. , Hibbins R. E. , Newnham D. A.
Published: January 2013

Abstract. This paper presents mesospheric carbon monoxide (CO) data acquired by the ground-based microwave radiometer of the British Antarctic Survey (BAS radiometer) stationed at Troll station in Antarctica (72° S, 2.5° E, 1270 a.m.s.l.). The data set covers the period from February 2008 to January 2010, however, due to very low CO concentrations below approximately 80 km altitude in summer, profiles can only be retrieved during Antarctic winter. CO is measured for approximately 2 h each day and profiles are retrieved approximately every half hour. The retrieved profiles, covering the pressure range from 1 to 0.01 hPa (approximately 48 to 80 km), are compared to measurements from Aura/MLS and SD-WACCM. This intercomparison reveals a low bias of 0.5 to 1 ppmv at 0.1 hPa (approximately 64 km) and 2.5 to 3.5 ppmv at 0.01 hPa (approximately 80 km) of the BAS microwave radiometer compared to both reference datasets. One explanation for this low bias could be the known high bias of MLS which is in the same order of magnitude. The ground based radiometer shows high and significant correlation (coefficients higher than 0.9/0.65 compared to MLS/SD-WACCM) at all altitudes compared with both reference datasets. doi:10.5285/DE3E2092-406D-47A9-9205-3971A8DFB4A9