bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of Polymer and Fiber on the Properties of Special Plaster Mortar for Aerated Concrete
Authors: Xiao Li Guang , Liu Gang , Yan Cun You , Xu Xiao Xian
Published: April 2013

As a new self-Insulation wall material, the autoclaved aerated concrete block has many advantages such as lightweight, thermal insulation, waste recycling, low energy consumption, friendly to environment, etc. It is gaining favors in the construction market day by day, and has been more and more widely used in construction engineering program. However, aerated concrete block faces disadvantages, e.g. large volume deformation coefficient, high water absorption, low strength, brittle character, etc. When aerated concrete block is used in combination with plain mortar, many problems may appear due to the incompatibility between them, for example crevices on the wall, large cracking, hollowing and exfoliation on the plaster layer, which become more serious on the north-facing wall in the cold region. These problems greatly hinder the wide application of aerated concrete block. Therfore, it is critical to develop a special plaster mortar that is compatible with the aerated concrete block. This paper concentrates on the chemical admixtures such as polymer and fiber, and studies their influences on the performance of the special plaster mortar. The experimental results show that polymer powder can significantly improve the properties of plaster mortar such as bonding strength, absorption performance and cohesive quality. Also, it prevents the bleeding and segregation of the paste, prevents the hollowing and exfoliation of plaster mortar layer on aerated concrete block wall. Polypropylene fiber has been revealed to increase the fracture toughness and cracking resistance of plaster mortar, thus preventing the cracking of plaster mortar layer on aerated concrete block wall. Additionally, this paper presents the microstructure of plaster mortar and discusses the working mechanism of admixtures in the mortar.
Performance of Low Modulus Fibers in Engineered Cementitious Composites (ECCs): Flexural Strength and Pull out Resistance
Authors: Halvaei Mana , Jamshidi Masoud , Latifi Masoud , Behdouj Zahra
Published: April 2013

Cement based materials are brittle in nature. Fibers have been used to improve flexural/tensile behaviors of the cementitious materials from one hundred years ago. Recently, a new generation of high performance fiber reinforced cementitious composites (HPFRCCs) has been introduced by Professor V.C. Li which was called Engineered Cementitious Composite (ECC). ECC showed incredible flexural and tensile strengths as it was called as flexible concrete by some researchers. Usually, high modulus fibers have been used in ECCs as reinforcement. In this research, homemade low modulus fibers (acrylic, nylon 66 and polypropylene) were used as reinforcement in ECC. Flexural strength test were performed on the ECC sheets. Also, Pull out test was performed to determine adhesion energy and toughness between the fibers and the matrix. It was found that low modulus fibers caused lower flexural strength and bonding to matrix than PVA fibers. However, they were found as suitable fibers for products with good cost-quality balance especially for construction purposes.
Influences of Processing and Testing Conditions on Flexural Behavior of Fiber-Reinforced Polymer-Modified Cement Mortar
Authors: Chen Wei Deng , Zhong Shi Yun
Published: April 2013

In order to evaluate the flexural behavior of fiber-reinforced polymer cement mortar, three-point bending test is used. Compared with different test modes and different test rates of loading, 0.1 mm/min in displacement mode is the most suitable, under which the obtained data are stable and sensitive to the micro-crack formation. Besides, tests show that mixing fiber-reinforced polymer cement mortar at slow speed and curing specimens in dry condition benefit the behavior under flexural load of the mortar.
Driving Forces Concrete-Polymer Composites
Authors: Czarnecki Lech , Özkul Hulusi , Wang Ru
Published: April 2013

The aim of the paper is an attempt to prepare draft about the matrix: drivers and research area in the C-PC with an intension to identify future research needs and priorities with relevance to C-PC development. The approach adopted in the paper is limited to the two terms: “drivers” and “research area”. Drivers have been selected to the research areas defined on the base of the 14th ICPIC which reflect general scope of the C-PC domain. However, the identification and prioritization is not yet precise and do not define the result but try to establish the starting point. The purpose is that the paper is going to be used as a catalyst to guide discussion among the members of the C-PC community and to maximise the output in C-PC.
Study on the Structure and Vibrational Spectra of Functionalized Au Nanoparticles: Theoretical and Experimental Results
Authors: Rodríguez-Ortiz G. , Téllez-Vázquez O. , Gutiérrez-Wing C. , Esparza Muñoz Rodrigo Alonso , Pérez R.
Published: April 2013

Structural and spectral characteristics of functionalized Au nanoparticles have been studied by electron microscopy, vibrational spectroscopy and quantum chemical methods. Gold nanoparticles were synthesized through a microwave induced reaction, starting with a two phase system using 1-dodecanethiol as passivating agent. The nanoparticles were structurally characterized using aberration-corrected scanning transmission electron microscopy (Cs-STEM) equipped with a high-angle annular dark field (HAADF) detector. The main structures of the nanoparticles were fcc-like and icosahedrons. Density functional theory (DFT) calculations, optimized geometries and vibrational spectra, have been carried out using 6-31G* basis sets and B3LYP functional. The experimental and theoretical infrared spectra of the functionalized Au nanoparticles show the main absorption peaks from 1-dodecanethiol, C-H stretch from CH2 at 2917, 2848 and from CH3 at 2954 and 2872 cm-1, C-H from-CH2 deformation at 1467 and from CH3 at 1376 cm-1. Infrared spectra of octanethiol and gold nanoparticles functionalized with octanethiol were also obtained. These nanostructures can be used in applications such as diagnostics, biosensing, therapeutics, and drug delivery.
Synthesis of Ag Nanoparticles-Clinoptilolite Composite by Homogeneous and Heterogeneous Nucleation
Authors: Ruíz-Baltazar A. , Esparza Muñoz Rodrigo Alonso , Pérez R. , Rosas Trejo Gerardo Antonio
Published: April 2013

In this study, a natural zeolite clinoptilolite-type was impregnated through homogeneous and heterogeneous nucleation with silver nanoparticles. The synthesis of Ag nanoparticles was carried out by chemical reduction of silver nitrate (AgNO3) with sodium borohydride (NaBH4). In the case of homogeneous nucleation, colloidal solution of Ag nanoparticles at concentrations of 1, 2 and 4 parts per million was added and magnetically mixed with the porous material. With respect to heterogeneous nucleation, a solution of clinoptilolite and silver nitrate (0.01 M) was prepared and stirred; subsequently, the reduction of Ag was possible due to the addition of an aqueous solution of sodium borohydride. For the structural characterization, transmission electron microscopy (TEM), X-ray diffraction (XRD) and infrared spectroscopy (IR) techniques were carried out. The results were compared and discussed in both types of nucleation.
Galectin 1 Modulates Plasma Cell Homeostasis and Regulates the Humoral Immune Response
Authors: Anginot Adrienne , Espeli Marion , Chasson Lionel , Mancini Stéphane J. C. , Schiff Claudine
Published: April 2013

Galectin-1 (GAL1) is an S-type lectin with multiple functions, including the control of B cell homeostasis. GAL1 expression was reported to be under the control of the plasma cell master regulator BLIMP-1. GAL1 was detected at the protein level in LPS-stimulated B cells and was shown to promote Ig secretion in vitro. However, the pattern of GAL1 expression and function of GAL1 in B cells in vivo are still unclear. In this study, we show that, among B cells, GAL1 is only expressed by differentiating plasma cells following T-dependent or T-independent immunization. Using GAL1-deficient mice we demonstrate that GAL1 expression is required for the maintenance of Ag-specific Ig titers and Ab-secreting cell numbers. Using an in vitro differentiation assay we find that GAL1-deficient plasmablasts can develop normally but die rapidly, through caspase 8 activation, under serum starvation–induced death conditions. TUNEL assays show that in vivo–generated GAL1-deficient plasma cells exhibit an increased sensitivity to apoptosis. Taken together, our data indicate that endogenous GAL1 supports plasma cell survival and participates in the regulation of the humoral immune response.
Programmed Death Receptor-1/Programmed Death Receptor Ligand-1 Blockade after Transient Lymphodepletion To Treat Myeloma
Authors: Kearl Tyce J. , Jing Weiqing , Gershan Jill A. , Johnson Bryon D.
Published: April 2013

Early phase clinical trials targeting the programmed death receptor-1/ligand-1 (PD-1/PD-L1) pathway to overcome tumor-mediated immunosuppression have reported promising results for a variety of cancers. This pathway appears to play an important role in the failure of immune reactivity to malignant plasma cells in multiple myeloma patients, as the tumor cells express relatively high levels of PD-L1, and T cells show increased PD-1 expression. In the current study, we demonstrate that PD-1/PD-L1 blockade with a PD-L1–specific Ab elicits rejection of a murine myeloma when combined with lymphodepleting irradiation. This particular combined approach by itself has not previously been shown to be efficacious in other tumor models. The antitumor effect of lymphodepletion/anti–PD-L1 therapy was most robust when tumor Ag–experienced T cells were present either through cell transfer or survival after nonmyeloablative irradiation. In vivo depletion of CD4 or CD8 T cells completely eliminated antitumor efficacy of the lymphodepletion/anti–PD-L1 therapy, indicating that both T cell subsets are necessary for tumor rejection. Elimination of myeloma by T cells occurs relatively quickly as tumor cells in the bone marrow were nearly nondetectable by 5 d after the first anti–PD-L1 treatment, suggesting that antimyeloma reactivity is primarily mediated by preactivated T cells, rather than newly generated myeloma-reactive T cells. Anti–PD-L1 plus lymphodepletion failed to improve survival in two solid tumor models, but demonstrated significant efficacy in two hematologic malignancy models. In summary, our results support the clinical testing of lymphodepletion and PD-1/PD-L1 blockade as a novel approach for improving the survival of patients with multiple myeloma.
Human Fc Receptor–Like 5 Binds Intact IgG via Mechanisms Distinct from Those of Fc Receptors
Authors: Franco Andrea , Damdinsuren Bazarragchaa , Ise Tomoko , Dement-Brown Jessica , Li Huifang , Nagata Satoshi , Tolnay Mate
Published: April 2013

Fc receptor–like (FCRL) 5 regulates B cell Ag receptor signaling and has been reported to bind aggregated IgG. Using surface plasmon resonance, we analyzed the interaction of native IgG samples with FCRL5, revealing a complex binding mechanism, where isotype is just one factor. FCRL5 bound IgG1 and IgG4 with ∼1 μM KD, whereas the interaction with IgG3 was a magnitude weaker. However, IgG2 samples displayed a wide range of affinities, indicating that additional factors affect binding. We used a panel of 19 anti-FCRL5 mAbs with defined reactivity to identify domains involved in ligand binding. Six mAbs blocked IgG binding, indicating critical roles of FCRL5 domains 1 and 3, as well as epitopes at the domain 1/2 and domain 2/3 boundaries. We found that only glycosylated IgG containing both Fab arms and the Fc region bound with high affinity. Furthermore, the presence of sialic acid in the IgG carbohydrate altered FCRL5 binding. The interaction of IgG and FCRL5 consisted of two kinetic components, suggesting a complex binding mechanism. We established that the IgG-Fc and IgG-F(ab′)2 fragments bind FCRL5 independently but with low affinity, revealing the mechanism behind the two-step binding of whole IgG. This complex binding mechanism is distinct from that of Fc receptors, which bind through the Fc. We propose that FCRL5 is a new type of receptor that recognizes intact IgG, possibly enabling B cells to sense Ig quality. Recognition of undamaged IgG molecules by FCRL5 could allow B cells to engage recently produced Abs.
Genome-wide Analysis of Immune System Genes by Expressed Sequence Tag Profiling
Authors: Giallourakis Cosmas C. , Benita Yair , Molinie Benoit , Cao Zhifang , Despo Orion , Pratt Henry E. , Zukerberg Lawrence R. , Daly Mark J. , Rioux John D. , Xavier Ramnik J.
Published: April 2013

Profiling studies of mRNA and microRNA, particularly microarray-based studies, have been extensively used to create compendia of genes that are preferentially expressed in the immune system. In some instances, functional studies have been subsequently pursued. Recent efforts such as the Encyclopedia of DNA Elements have demonstrated the benefit of coupling RNA sequencing analysis with information from expressed sequence tags (ESTs) for transcriptomic analysis. However, the full characterization and identification of transcripts that function as modulators of human immune responses remains incomplete. In this study, we demonstrate that an integrated analysis of human ESTs provides a robust platform to identify the immune transcriptome. Beyond recovering a reference set of immune-enriched genes and providing large-scale cross-validation of previous microarray studies, we discovered hundreds of novel genes preferentially expressed in the immune system, including noncoding RNAs. As a result, we have established the Immunogene database, representing an integrated EST road map of gene expression in human immune cells, which can be used to further investigate the function of coding and noncoding genes in the immune system. Using this approach, we have uncovered a unique metabolic gene signature of human macrophages and identified PRDM15 as a novel overexpressed gene in human lymphomas. Thus, we demonstrate the utility of EST profiling as a basis for further deconstruction of physiologic and pathologic immune processes.
Cd72c Is a Modifier Gene that Regulates Faslpr-Induced Autoimmune Disease
Authors: Xu Miduo , Hou Rong , Sato-Hayashizaki Aya , Man Rongyong , Zhu Chenghua , Wakabayashi Chisato , Hirose Sachiko , Adachi Takahiro , Tsubata Takeshi
Published: April 2013

Although modifier genes are extensively studied in various diseases, little is known about modifier genes that regulate autoimmune diseases. Autoimmune disease caused by the Faslpr mutation depends on the genetic background of mouse strains, suggesting a crucial role of modifier genes. MRL/MpJ-Faslpr (MRL/lpr) and AKR/lpr mice develop severe and mild lupus-like autoimmune disease, respectively, whereas this mutation does not cause disease on C57BL/6 (B6) or C3H background. Both MRL and AKR carry the same haplotype of the Cd72 gene encoding an inhibitory BCR coreceptor (CD72c), and CD72c contains several amino acid substitutions and a deletion in the extracellular region compared with CD72a and CD72b. To address the role of Cd72c locus in the regulation of Faslpr-induced autoimmune disease, we generated B6.CD72c/lpr and MRL.CD72b/lpr congenic mice. Introduction of the chromosomal interval containing Cd72c did not cause disease in B6 mice by itself, but caused development of lupus-like disease in the presence of Faslpr on B6 background, clearly demonstrating that this interval contains the modifier gene that regulates Faslpr-induced autoimmune disease. Conversely, MRL.CD72b/lpr congenic mice showed milder disease compared with MRL/lpr mice. We further demonstrated that Cd72c is a hypofunctional allele in BCR signal inhibition and that CD72 deficiency induces severe autoimmune disease in the presence of Faslpr. These results strongly suggest that the Cd72c is a crucial modifier gene that regulates Faslpr-induced autoimmune disease due to its reduced activity of B cell signal regulation.
Lithostratigraphy, sedimentology, paleontology, organic petrology, and organic geochemistry of the Middle Devonian Ashern, Winnipegosis, and Eyot formations in east-central Alberta and west-central Saskatchewan
Authors: Meijer Drees N C , Nowlan G S , Fowler M G , Stasiuk L
D , McGregor D C , Palmer B R , Addison G
D
Published: April 2013

The Middle Devonian succession in the subsurface of east-central Alberta and west-central Saskatchewan unconformably overlies Cambrian and Ordovician strata. It locally onlaps the Red River subcrop ridge along the Ordovician subcrop edge, which extends into
west-central Saskatchewan as the Meadow Lake Escarpment. The succession includes the basal transgressive clastic rocks of the Ashern Formation, overlain by a shelf-like wedge of carbonate deposits that forms the Winnipegosis Formation. The Winnipegosis Formation increases in thickness to the east
and is in lateral contact with the lower part of the Prairie evaporite deposits of west-central Saskatchewan. In central Alberta the upper part of the Prairie evaporite deposits overlies the Winnipegosis Formation and changes laterally into dolomitic shale and siltstone of the newly proposed Eyot
Formation. Because the informal subdivision in the basinal part of the Winnipegosis Formation in Manitoba and Saskatchewan is not useful in the marginal part of west-central Alberta, four new members are introduced in Alberta. In ascending order they are the Eyehill, Cutknife, Killam, and Bawif. The
Eyehill Member is in mappable continuity with the lower Winnipegosis member of southern Saskatchewan and extends westward into east-central Alberta. The Cutknife is in mappable continuity with the upper Winnipegosis member of southwestern Saskatchewan and extends westward beyond the depositional
limit of the Eyehill. In west-central Saskatchewan both the Killam and the Bawif members are in lateral facies contact with the upper part of the Shell Lake Member of the Prairie Formation. They extend westward into east-central Alberta beyond the depositional limit of the Eyehill Formation. Thin
carbonaceous and bituminous shale interbeds are present in the clastic and shelf carbonate deposits. Carbonaceous shale contains up to 54% total organic carbon (TOC), and hydrogen indices (HI) range between 170 and 367 mg hydrocarbons (HC) per gram (g) TOC. Bituminous shale contains up to
12% TOC and HI range up to 744 mg HC/g TOC. Organic-rich units in the lower part of the Ashern Formation include organic matter derived from land plants, while those in the upper part also include organic material derived from marine organisms. The carbonaceous material in beds associated with
marginal-marine and marine carbonate of the Winnipegosis contains mostly Type III kerogen, and that in the anhydritic carbonate includes Type II and Type III kerogens.
Several of the carbonaceous shale samples yielded well-preserved spores and other microfossils. Spores diagnostic of the Givetian Stage were obtained from the Ashern, Winnipegosis, and Eyot formations. The Cutknife Member includes Stringocephalus brachiopods, also diagnostic for the
Givetian.
Constructing ancient slavery as socio-historic context of the New Testament
Authors: Goede Hendrik
Published: April 2013

Considering the vast scope of material on slavery in antiquity, this article aimed to design a search filter that delimits the scope of socio-historical aspects specifically relevant to the New Testament passages dealing with slavery. The term ‘search filter’ was borrowed from Information Technology, denoting defined search terms aimed at more efficient and effective searches of vast amounts of data. The search filter designed in this article made use of the following search terms: the period under investigation; the geographical region under investigation; various definitions of slavery; ancient terminology for slavery; and aspects arising from the New Testament passages themselves. Each of these criteria were considered in turn, and the results were used to define the search filter. Finally, the search filter was represented schematically.
The role of the Jotello F. Soga Library in the digital preservation of South African veterinary history
Authors: Breytenbach Amelia , Lourens Antoinette , Marsh Susan
Published: April 2013

The history of veterinary science in South Africa can only be appreciated, studied, researched and passed on to coming generations if historical sources are readily available. In most countries, material and sources with historical value are often difficult to locate, dispersed over a large area and not part of the conventional book and journal literature. The Faculty of Veterinary Science of the University of Pretoria and its library has access to a large collection of historical sources. The collection consists of photographs, photographic slides, documents, proceedings, posters, audio-visual material, postcards and other memorabilia. Other institutions in the country are also approached if relevant sources are identified in their collections. The University of Pretoria’s institutional repository, UPSpace, was launched in 2006. This provided the Jotello F. Soga Library with the opportunity to fill the repository with relevant digitised collections of diverse heritage and learning resources that can contribute to the long-term preservation and accessibility of historical veterinary sources. These collections are available for use not only by historians and researchers in South Africa but also elsewhere in Africa and the rest of the world. Important historical collections such as the Arnold Theiler collection, the Jotello F. Soga collection and collections of the Onderstepoort Journal of Veterinary Research and the Journal of the South African Veterinary Association are highlighted. The benefits of an open access digital repository, the importance of collaboration across the veterinary community and other prerequisites for the sustainability of a digitisation project and the importance of metadata to enhance accessibility are covered.
Fertility Preservation Options after Gonadotoxic Chemotherapy
Authors: Hyman Jordana Hadassah , Tulandi Togas
Published: April 2013

Chemotherapy has the potential to deplete and destroy a woman's reproductive potential. Although many oncologists are referring women for fertility preservation before chemotherapy, in many cases there is limited time for fertility preservation. This review provides an overview of the impact of cancer and chemotherapy on the ovarian reserve, a summary of methods of fertility preservation prior to chemotherapy, and current knowledge of fertility preservation techniques after gonadotoxic chemotherapy.
Spatial and temporal variability of soil horizons and long-term solute transport under semi-arid conditions
Authors: Woods S. A. , Dyck M. F. , Kachanoski R. G.
Published: April 2013

Woods, S. A., Dyck, M. F. and Kachanoski, R. G. 2013. Spatial and temporal variability of soil horizons and long-term solute transport under semi-arid conditions. Can. J. Soil Sci. 93: 173–191. Characterizing the spatial and temporal variability of deep drainage is required for quantifying risks to groundwater resources associated with chemicals released into the soil. A variety of approaches are available to characterize the spatial variability of deep drainage, including complex, spatially explicit hydrological models or simpler, distributed soil water balance models. There is no clear understanding which approach is most appropriate for a given landscape. In this paper we compare the spatial distribution of an applied chloride tracer to pedogenic nitrate and sulphate salts, subject to transport in the soil over decadal to millennial time scales, to characterize the relative spatial and temporal differences in deep drainage at a site in southern Saskatchewan. Comparison of the spatial distribution of the salts with differing soil residence times showed that the soil water balance and deep drainage fluxes have changed significantly over time in some parts of the landscape because of infilling of surface depressions as indicated by the presence of buried A horizons. At larger scales, the distribution of the salts showed very little correspondence to the spatial distribution and thicknesses of soil horizons (often used to infer spatial variability in soil water balance), but was more consistent with the scale of the surface topography. Thus it was concluded that spatial and temporal changes in surface topography (i.e., catchment area) were the primary factors responsible for the observed transport of the salts. We propose that this site is representative of the cold, semi-arid prairies and that these conclusions likely apply to this region.
Ammonia volatilization losses were small after mowing field peas in dry conditions
Authors: Engel Richard , Jones Clain , Wallander Rosie
Published: April 2013

Engel, R., Jones, C. and Wallander, R. 2013. Ammonia volatilization losses were small after mowing field peas in dry conditions. Can. J. Soil Sci. 93: 239–242. Ammonia losses following termination of peas (Pisum sativum L.) by mowing were measured using a micrometeorological mass-balance approach. Field trials were conducted during two seasons in a semiarid climate. Plant N in the above ground biomass was 105 and 79 kg N ha−1 in 2011 and 2012, respectively. Vertical NH3 flux estimates were nominal (0.3 to 1.7 g N ha−1 h−1) in the 2 wk following mowing. Cumulative NH3 loss represented 0.3 to 0.5% of the N in plant biomass, indicating that N fertility was not diminished by NH3 volatilization in this dry climate.
Effects of flow rates and composition of the filter, and decay/ingrowth correction factors involved with the determination of in situ particulate 210Po and 210Pb in seawater
Authors: Baskaran Mark , Church Thomas , Hong Gi , Kumar Anupam , Qiang Ma , Choi Hiu , Rigaud Sylvain , Maiti Kanchan
Published: April 2013

Accurate measurements of particulate 210Po (210Pop) and 210Pb (210Pbp) are required in the investigation of (i) partitioning of Po and Pb between particulate and dissolved phases and (ii) export estimates of carbon and other key trace metals from the euphotic zone via sinking particulate matter. Based on the intercomparison of different composition of the filter material (QMA, Supor, Millipore, and Pall GN6) and flow rates (2 to 8 L min), we show how these factors affect the measured concentrations of 210Pop and 210Pbp and their activity ratios (AR). As such, we recommend using Supor 0.4 µm filter and a flow rate of up to 8 L/min for the measurements of 210Pop and 210Pbp. Furthermore, we inter‐compared 210Pop and 210Pbp obtained by small‐volume McLane and large‐volume MULVFS pumps. The activities of 210Pop in MULVFS filter samples are somewhat higher than that of McLane filter samples, whereas the 210Po/210Pb AR collected by McLane pump is distinctly lower, suggesting some fractionation in the collection process by the pumping systems. Likewise comparison of vertical profiles of 210Pop and 210Pbp obtained using McLane pumps by two independent research groups at the two intercalibration stations in the Pacific Ocean show quite similar values except in the mesopelagic waters, suggesting possible uneven loading and presence of larger gelatinous plankton in the filter. Finally, we append a detailed analysis of various correction factors for the accurate calculation of in situ 210Po and 210Pb. Presented results are relevant to the worldwide community that uses 210Po‐210Pb as tracers in aquatic systems.
Three‐dimensional tracking of multiple aquatic organisms with a two camera system
Authors: Noss C. , Lorke A. , Niehaus E.
Published: April 2013

A new constraint assignment algorithm and a two‐perspective tracking method are presented for three‐dimensional tracking of motile aquatic organisms. The method aims at providing preferably long tracks of multiple, simultaneously swimming individuals. As an extension to existing tracking and assignment methods, the presented algorithm takes background knowledge about maximum swimming speed and size of the organisms into account. Two strategies, both using the constraint assignment algorithm, were applied to track either a fixed number of objects or to track as many objects as possible in frame‐to‐frame transitions. Whereas the first strategy provides continuous and distinct tracks of all individuals for the entire measurement sequence, the second strategy does not require interpolation of unresolved positions and is more robust to disappearance or reappearance of organisms within the field of view. Two sets of video records of freely swimming Daphnia magna, differing in abundance, image quality, and record length, are analyzed to assess the tracking success of the proposed algorithm. Although both strategies provide better results for a higher detection rate of organisms, the first strategy is preferable for tracking individuals in tests with smaller organism abundance and higher signal‐to‐noise ratio, whereas the second strategy also provides reasonable pathways under less optimal conditions. Spectral analysis of observed swimming velocities is applied to demonstrate the advantage of obtaining long, continuous, and three‐dimensional tracks of moving organisms.
High‐resolution analysis of shoreline change and application of balloon‐based aerial photography, Albemarle‐Pamlico Estuarine System, North Carolina, USA
Authors: Eulie Devon Olivola , Walsh J.P. , Corbett D. Reide
Published: April 2013

Previous studies of shorelines have relied on satellite imagery or airplane‐based aerial photography, which can be costly, of limited availability, and of restricted resolution. These factors limit the usefulness of such imagery for detailed shoreline‐change measurements that require frequent observations with high spatial accuracy. Easily deployed balloon‐based photography systems can provide high spatial and temporal resolution images at relatively low cost. This study used an Aerostat balloon photography system along with real‐time kinematic (RTK) GPS to observe subannual changes in the shoreline position of the Albemarle‐Pamlico Estuarine System (APES), North Carolina, USA. The fine (0.03 m‐pixel) resolution of Aerostat images is ideal for mapping shoreline areas although limited in spatial extent. Features digitized from these images compare well in position (0.5 ± 0.5 m) and accuracy (± 0.4 m) to in situ RTK‐GPS surveys. The balloon system is best used concurrently with RTK‐GPS surveys to obtain the highest possible georectification accuracy. Results demonstrate that this method is well suited to high‐accuracy analysis of shoreline positions over short timescales (annual to subannual), and that the balloon images provide a valuable spatial context for any measured changes. Preliminary analysis of shoreline change across the APES highlights great spatial and temporal complexity. Annualized rates of change reached >30 m/y, but average net changes were modest for survey periods (−0.5 m to 0.04 m). Tropical systems (e.g., Hurricane Earl) can be key drivers of the observed shoreline response, and the associated sediment dynamics likely have important ecological (e.g., submerged‐aquatic‐vegetation and water quality) ramifications.
Different mixing techniques in experimental mesocosms—does mixing affect plankton biomass and community composition?
Authors: Striebel Maren , Kirchmaier Leo , Hingsamer Peter
Published: April 2013

Over the past four decades, mesocosm studies have been successfully used for a wide range of applications and have provided a lot of information on trophic interactions and biogeochemical cycling of aquatic ecosystem. However, the setup of such mesocosms (e.g., dimensions and duration of experiments) needs to be adapted to the relevant biological processes being investigated. Mixing of the water column is an important factor to be considered in mesocosm experiments because enclosing water in an artificial chamber always alters the mixing regime. Various approaches have been applied to generate mixing in experimental ecosystems, including pure mechanical mixing (e.g., using a disc), airlifts, bubbling with compressed air, and pumping. In this study, we tested different mixing techniques for outdoor mesocosms and their impact on plankton biomass and community composition. We compared mesocosms mixed with a disc, an airlift‐system, and bubbling, and used a nonactively mixed mesocosm as a control. We investigated phytoplankton, ciliate, and zooplankton communities during a 19‐d mesocosm experiment. Based on our results, we concluded that mechanical mixing with a disc was the most effective technique due to the undertow produced by lowering and lifting the disc. While no mixing technique affected seston biomass, zooplankton biomass was highest in the treatments mixed with the disc. The airlift treatments had the lowest relative share of small flagellates. However, no further differences in phytoplankton community composition occurred and no differences in zooplankton community composition existed between all actively mixed treatments.
O exercício da arquitetura da informação na Web: reflexões relativas à Lei dos Direitos Autorais
Authors: Sousa Rosilene Paiva Marinho de , Dias Guilherme Ataíde , Oliveira Bernardina , Sousa Marckson
Published: April 2013

Apresenta uma reflexão sobre a Arquitetura da Informação (AI) e a Lei nº 9.610, de 19 de fevereiro de 1998, que regula os Direitos Autorais, considerando-se o livre acesso à informação, sem esquecer as questões éticas e legais. A metodologia aplicada é de natureza qualitativa, bibliográfica e de caráter exploratório. São abordados os componentes da Arquitetura da Informação, além de tecer uma discussão sobre os direitos autorais pertinentes aos referidos componentes da AI existentes nos websites. O livre acesso à informação é um fator primordial, mas devem ser impostas exigências que regulamentem projetos derivados, atentando-se para as leis que regulamentam os direitos autorais e produtos de software, levando em consideração o conteúdo neles expostos, para possíveis modificações.
Estudo sociocultural da comunidade discursiva do tratamento temático da informação em bibliotecas universitárias
Authors: Dal' Evedove Paula Regina , Fujita Mariângela Spotti Lopes
Published: April 2013

Parte-se da prerrogativa de que o conhecimento individual é socialmente condicionado e, por isso, torna-se necessário investigar o conhecimento dos profissionais que influenciam direta ou indiretamente os produtos gerados no tratamento temático da informação em contexto de bibliotecas universitárias. Para tanto, analisa-se a comunidade discursiva do tratamento temático da informação a partir do contexto institucional e interação social por meio de entrevista estruturada. Os resultados revelaram a necessidade da Ciência da Informação avançar no estabelecimento de estudos que cerquem questões que envolvam a ação humana a partir da realidade social objetiva, a fim de aprimorar as concepções teóricas e metodológicas do tratamento temático da informação em contexto de bibliotecas universitárias.
A macro-level study of science in Brazil: seven years later
Authors: Leta Jacqueline , Thijs Bart , Glänzel Wolfgang
Published: April 2013

Following earlier studies by the authors published in 2006, the evolution of publication activity and citation impact in Brazil is studied for more recent years up to 2011. Similarly to these studies, an analysis of publication and citation patterns and of national publication profiles is conducted to make it possible to compare recent trends with patterns found earlier. An attempt is made to find also statistical evidences of the relation between international co-authorship and both research profile and citation impact in the Latin American region. The authors compare their results with finding from other bibliometric studies of BRICS and N-11 countries. The enormous growth of Brazilian publication output forms the largest potential reaching far beyond the Latin American world region.
Key Sectors in the Moroccan Economy: An Application of Input-Output Analysis
Authors: Tounsi Said , Ezzahid El hadj , Alaoui Aicha El , Nihou Abdelaziz
Published: April 2013

The exploration of the structural features and sectoral interdependences of and in an economy is fundamental for the understanding of its modes of functioning and of its transformations over time. Input-output analysis is largely used to fulfill this objective. Furthermore, information provided by the Leontief inverse matrix is useful for the identification of key sectors. This identification may guide policy makers in setting an adequate industrial strategy. In this paper, the classification of productive sectors is performed by using the Unweighted Rassmussen Approach. The ordering of sectors depends on the intensity of their links with other sectors. Two results ought to be highlighted. First, key sectors of the Moroccan economy (sectors that are classified in category II) reduced to two sectors in 2007 instead of four sectors in 1998. Second, the ordering of sectors is highly sensitive to the precision of the data and to the year in which the classification is realized.
The 2007–2011 evolution of tropical methane in the mid-troposphere as seen from space by MetOp-A/IASI
Authors: Crevoisier C. , Nobileau D. , Armante R. , Crépeau L. , Machida T. , Sawa Y. , Matsueda H. , Schuck T. , Thonat T. , Pernin J. , Scott N. A. , Chédin A.
Published: April 2013

Abstract. Since July 2007, monthly averages of mid-tropospheric methane have been retrieved in the tropics over land and sea, by day and night, from IASI onboard MetOp-A, yielding a complete view of the geographical distribution, seasonality and long-term tendency of methane in the mid-troposphere. Retrieved methane displays a clear seasonal cycle of ~25 ppbv in the northern tropics, with a maximum in November and a minimum in April–May, a more complex cycle of ~15 ppbv in the southern tropics, and a south-to-north latitudinal variation of ~30 ppbv – in good agreement with regular aircraft measurements of the CONTRAIL program. Comparisons with CARIBIC aircraft measurements made at ~11 km yield an averaged difference between collocated IASI estimates and CARIBIC measurements of 7.2 ppbv with a standard deviation of 13.1 ppbv. Comparisons with aircraft measurements made above 6 km during five HIPPO campaigns give an averaged difference between collocated IASI estimates and HIPPO measurements of 5.1 ppbv with a standard deviation of 16.3 ppbv. These comparisons show that IASI captures well the evolution of mid-tropospheric methane. In particular, in 2007 and 2008, IASI shows an increase of mid-tropospheric methane in the tropical region of 9.5 ± 2.8 and 6.3 ± 1.7 ppbv yr−1, respectively – in excellent agreement with the rate of increase measured at the surface after almost a decade of near-zero growth. IASI also indicates a slowing down of this increase in the following years to ~2 ppbv yr−1, with the highest increase in 2010. Assuming that the recent evolution of methane is mostly due to an increase in surface emissions, IASI might indicate a decrease in tropical wetland emissions for the period 2009–2011 compared to 2007–2008, in agreement with decreasing tropical precipitation over this period, together with an increase in biomass burning emissions in 2010 in the southern tropics.
Volatile organic compounds in the western Mediterranean basin: urban and rural winter measurements during the DAURE campaign
Authors: Seco R. , Peñuelas J. , Filella I. , Llusia J. , Schallhart S. , Metzger A. , Müller M. , Hansel A.
Published: April 2013

Abstract. Atmospheric volatile organic compounds (VOCs) have key environmental and biological roles, but little is known about the daily VOC mixing ratios in Mediterranean urban and natural environments. We measured VOC mixing ratios concurrently at an urban and a rural site during the winter DAURE campaign in the northeastern Iberian Peninsula, by means of PTR-MS at both locations: a PTR-Quad-MS at the urban site and a PTR-ToF-MS at the rural site. All VOC mixing ratios measured were higher at the urban site (e.g. acetaldehyde, isoprene, benzene, and toluene with averages up to 1.68, 0.31, 0.58 and 2.71 ppbv, respectively), with the exception of some short-chain oxygenated VOCs such as acetone (with similar averages of 0.7–1.6 ppbv at both sites). The average diurnal pattern also differed between the sites. Most of the VOCs at the urban location showed their highest mixing ratios in the morning and evening. These peaks coincided with traffic during rush hour, the main origin of most of the VOCs analyzed. Between these two peaks, the sea breeze transported the urban air inland, thus helping to lower the VOC loading at the urban site. At the rural site, most of the measured VOCs were advected by the midday sea breeze, yielding the highest daily VOC mixing ratios (e.g. acetaldehyde, isoprene, benzene, and toluene with averages up to 0.65, 0.07, 0.19, and 0.41 ppbv, respectively). Only biogenic monoterpenes showed a clear local origin at this site. In addition, the concentrations of fine particulate matter observed at both sites, together with the synoptic meteorological conditions and radio-sounding data, allowed the identification of different atmospheric scenarios that had a clear influence on the measured VOC mixing ratios. These results highlight the differences and relationships in VOC mixing ratios between nearby urban and rural areas in Mediterranean regions. Further research in other urban-rural areas is warranted to better understand the urban-rural influence on atmospheric VOC mixing ratios under different atmospheric conditions.
Seasonal and spatial variability of the OM/OC mass ratios and high regional correlation between oxalic acid and zinc in Chinese urban organic aerosols
Authors: Xing L. , Fu T.-M. , Cao J. J. , Lee S. C. , Wang G. H. , Ho K. F. , Cheng M.-C. , You C.-F. , Wang T. J.
Published: April 2013

Abstract. We calculated the organic matter to organic carbon mass ratios (OM/OC mass ratios) in PM2.5 collected from 14 Chinese cities during summer and winter of 2003 and analyzed the causes for their seasonal and spatial variability. The OM/OC mass ratios were calculated two ways. Using a mass balance method, the calculated OM/OC mass ratios averaged 1.92 ± 0.39 year-round, with no significant seasonal or spatial variation. The second calculation was based on chemical species analyses of the organic compounds extracted from the PM2.5 samples using dichloromethane/methanol and water. The calculated OM/OC mass ratio in summer was relatively high (1.75 ± 0.13) and spatially-invariant due to vigorous photochemistry and secondary organic aerosol (OA) production throughout the country. The calculated OM/OC mass ratio in winter (1.59 ± 0.18) was significantly lower than that in summer, with lower values in northern cities (1.51 ± 0.07) than in southern cities (1.65 ± 0.15). This likely reflects the wider usage of coal for heating purposes in northern China in winter, in contrast to the larger contributions from biofuel and biomass burning in southern China in winter. On average, organic matter constituted 36% and 34% of Chinese urban PM2.5 mass in summer and winter, respectively. We report, for the first time, a high regional correlation between Zn and oxalic acid in Chinese urban aerosols in summer. This is consistent with the formation of stable Zn oxalate complex in the aerosol phase previously proposed by Furukawa and Takahashi (2011). We found that many other dicarboxylic acids were also highly correlated with Zn in the summer Chinese urban aerosol samples, suggesting that they may also form stable organic complexes with Zn. Such formation may have profound implications for the atmospheric abundance and hygroscopic properties of aerosol dicarboxylic acids.
Dynamic evaluation of a multi-year model simulation of particulate matter concentrations over Europe
Authors: Lecœur È. , Seigneur C.
Published: April 2013

Abstract. A 9 yr air quality simulation is conducted from 2000 to 2008 over Europe using the Polyphemus/Polair3D chemical-transport model (CTM) and then evaluated against the measurements of the European Monitoring and Evaluation Programme (EMEP). The spatial distribution of PM2.5 over Europe shows high concentrations over northern Italy (36 μg m−3) and some areas of Eastern Europe, France, and Benelux, and low concentrations over Scandinavia, Spain, and the easternmost part of Europe. PM2.5 composition differs among regions. The operational evaluation shows satisfactory model performance for ozone (O3). PM2.5, PM10, and sulfate (SO4=) meet the performance goal of Boylan and Russell (2006). Nitrate (NO3−) and ammonium (NH4+) are overestimated, although NH4+ meets the performance criterion. The correlation coefficients between simulated and observed data are 63% for O3, 57% for PM10, 59% for PM2.5, 57% for SO4=, 42% for NO3−, and 58% for NH4+. The comparison with other recent 1 yr model simulations shows that all models overestimate nitrate. The performance of PM2.5, sulfate, and ammonium is comparable to that of the other models. The dynamic evaluation shows that the response of PM2.5 to changes in meteorology differs depending on location and the meteorological variable considered. Wind speed and precipitation show a strong negative day-to-day correlation with PM2.5 and its components (except for sea salt, which shows a positive correlation), which tends towards 0 as the day lag increases. On the other hand, the correlation coefficient is near constant for temperature, for any day lag and PM2.5 species, but it may be positive or negative depending on the species and, for sulfate, depending on the location. The effects of precipitation and wind speed on PM2.5 and its components are better reproduced by the model than the effects of temperature. This is mainly due to the fact that temperature has different effects on the PM2.5 components, unlike precipitation and wind speed, which impact most of the PM2.5 components in the same way. These results suggest that state-of-the-science air quality models reproduce satisfactorily the effect of meteorology on PM2.5 and therefore are suitable to investigate the effects of climate change on particulate air quality, although uncertainties remain concerning semivolatile PM2.5 components.
Emission ratio and isotopic signatures of molecular hydrogen emissions from tropical biomass burning
Authors: Haumann F. A. , Batenburg A. M. , Pieterse G. , Gerbig C. , Krol M. C. , Röckmann T.
Published: April 2013

Abstract. In this study, we identify a biomass-burning signal in molecular hydrogen (H2) over the Amazonian tropical rainforest. To quantify this signal, we measure the mixing ratios of H2 and several other species as well as the H2 isotopic composition in air samples that were collected in the BARCA (Balanço Atmosférico Regional de Carbono na Amazônia) aircraft campaign during the dry season. We derive a relative H2 emission ratio with respect to carbon monoxide (CO) of 0.31 ± 0.04 ppb/ppb and an isotopic source signature of −280 ± 41‰ in the air masses influenced by tropical biomass burning. In order to retrieve a clear source signal that is not influenced by the soil uptake of H2, we exclude samples from the atmospheric boundary layer. This procedure is supported by data from a global chemistry transport model. The ΔH2/ΔCO emission ratio is significantly lower than some earlier estimates for the tropical rainforest. In addition, our results confirm the lower values of the previously conflicting estimates of the H2 isotopic source signature from biomass burning. These values for the emission ratio and isotopic source signatures of H2 from tropical biomass burning can be used in future bottom-up and top-down approaches aiming to constrain the strength of the biomass-burning source for H2. Hitherto, these two quantities relied only on combustion experiments or on statistical relations, since no direct signal had been obtained from in-situ observations.