bluuebunny/crossref_metadata_2025 huggingface dataset:
Dynamic Modelling of Biofilm Reactors with Immobilised Sulfate-Reducing Bacteria
Authors: Hatzikioseyian Artin , Kousi Pavlina , Remoundaki Emmanouella , Tsezos Marios
Published: December 2015

This paper presents a simple, reliable and extensible dynamic biofilm model. The model simulates the case of Sulfate-Reducing Bacteria (SRB) grown as biofilm on the surface of an inert support material in a completely mixed bioreactor. The principles of microbial stoichiometry and thermodynamics combined with microbial kinetic equations and chemical reactions have been implemented in AQUASIM software. Simulation results predict the biofilm growth, the reactor bulk volume solute concentrations and their corresponding profiles in the biofilm layer. The interaction of metal ions with biogenic sulfide is also discussed as decontamination means for a wastewater stream containing high metal and sulfate concentrations.
Study on As Uptake and Rhizobacteria of Two as Hyperaccumulators Forward to As Phytoremediation
Authors: Chien Mei Fang , Makita Ryota , Sugawara Kazuki , Inoue Chihiro
Published: December 2015

As a strategy of arsenic-containing mine tailing soil, the application of arsenic hyper-accumulator plants such as Pteris vittata shows high potential. Previous studies suggest that the arsenic uptake by P. vittata is largely determined by arsenic speciation, which is strongly influenced by microbial activities. In this study, two arsenic hyper-accumulators, P. vittata that is a subtropical plant and Pteris multifida that has been found in northeastern Japan, were selected and the their rhizobacteria were investigated. Pot experiments of P. vittata and P. multifida cultivation were performed. The concentration of total arsenic in the plant samples was monitored by inductively coupled plasma - mass spectrometry. Microbes in the rhizosphere samples were investigated by 16S rDNA library analysis and arsenic resistant bacteria isolation. The results showed that both ferns accumulated As, while P. multifida was more resistant to cold weather. Two ferns presented different rhizobacterial communities and cultivatable bacteria number, but bacteria that contain As(III) oxidase gene or As(III) oxidation activity were confirmed in both rhizosphere samples. The results of present study suggested that the cultivation of ferns changed the microbial communities in soil (rhizosphere), and microbial activity in the rhizosphere played a role in As(III) oxidation. Since ferns absorbs As(III) and As(V) in different efficiency, this study provided hints when linking microbial As transformation to As uptake by ferns which is important when designing pre-treatment procedures of phytoremediation.
Phytoremediation of Heavy Metal Contaminated Soil by Selection of Plant Species
Authors: Luo Ting , Chan Brenda K.C. , Wang Rui Yong
Published: December 2015

Contamination of heavy metals in soil has raised potential long term environmental and health concerns due to its accumulation and possibility of entering the food chain. Being cost effective and simple operation, phytoremediation is seen as an emerging technology and promising solution to remediate polluted soils. In recent years, great effort has been concentrated on screening a variety of hyperaccumulators. This paper evaluates four plant species Solanumnigrum L.PterismultifidaPois, Pterisvittata L and Brassicajuncea grown under different heavy metal (Cu, Cd, Pb and Zn) concentration in greenhouse pot trial. From pot experiment, the mobility of contaminants (Cd and Zn) in soil were reduced by being concentrated and absorbed onto root tissues and stems in Solanumnigrum L. and Brassicajuncea whereas Cu and Pb were stabilized in the root tissues of all four plant species. The different transport phenomena towards different contaminants and the phytostablization ability makes these four plants suitable pioneer species in remediation and revegetation in abandoned copper, lead and zinc mine.
Ruthenium Recovery from Acetic Acid Waste Solution by Using PEI-Coated Biomass-Chitosan Composite Fiber
Authors: Kim Jeong Ae , Song Myung Hee , Yun Yeoung Sang
Published: December 2015

Polyethylenimine (PEI)-coated biomass-chitosan composite fiber (PBCF) was fabricated to recover Ru from acetic acid waste solution. The present work aimed to understand the effects of molecular weight of chitosan and drying method on stability and sorption performance of the PBCF. For this, the PBCF was prepared by extruding the mixed solutions of chitosan and Corynebacteriumglutamicum to form the composite fibers which were modified with ionic polymer, PEI. The degree of swelling of PBCFs prepared by hot-air, natural, and freeze drying methods were 1.25, 1.34, and 1.07 %, respectively, indicating that the freeze-drying method was the best. Batch biosorption studies showed that the maximum Ru uptake could be achieved with PBCF prepared with medium molecular weight chitosan, and could reach 34.1 mg/g, which was 7.9 times higher than that of the commercial ion exchange resin, LEWATIT® MonoPlus M 500 (4.3 mg/g). Therefore, PBCF can be considered as an alternative sorbent to synthetic resin for recovery of Ru form industrial acetic acid waste solution.
Organotrophic and Mixotrofic Sulfur Oxidation in an Acidic Salt Flat in Northern Chile
Authors: Escudero Lorena , Bijman Jonathan , Mariela Guajardo M. , Pueyo Mur Juan José , Chong Guillermo , Demergasso Cecilia
Published: December 2015

To understand the microbial community inhabiting in an acidic salt flat the phylogenetic diversity and the geochemistry of this system was compared to acid mine drainage (AMD) systems. The microbial community structure was assessed by DNA extraction/PCR/DGGE and secuencing for the 16S rRNA gene and the geochemistry was analyzed using several approaches. Prediction of metagenome functional content was performed from the 16S rRNA gene survey using the bioinformatics software package Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt). The geochemical results revealed a much lower iron concentration in the salt flat than in AMD systems (39 and 21804 mg L-1, respectively) and a significant difference in chloride levels. Sequences inferred to be from potential sulfur metabolizing organisms constituted up to 70% of the microbial community in the acidic salt flat meanwhile predominat iron-metabolizing acidophile populations were reported in AMD systems. Interestingly, the microbial assemblage in the acidic salt flat was dominated by mixotrophic and organotrophic sulfur oxidizers as well as by photoautotrophic acidophiles. Our results suggests that the salt concentration in Salar de Gorbea (average Cl-= 40 gL-1) is in the limit for the occurrence of chemolithotrophic oxidation of sulfur compounds. In addition, the investigation allows concluding that salinity rather than extremes of pH is the major environmental determinant of microbial community composition.
Bioremediation of Steel Plant Wastewater and Improved Electricity Generation in Bio-Electrochemical Desalination Cell
Authors: Pradhan Harapriya , Shinde Omkar A. , Ghangrekar Makarand M. , Sarkar Supriya
Published: December 2015

A new technology called microbial desalination cell (MDC) approaches a comprehensive way to design an innovative system for removal of organic matter and dissolved solids from wastewater. In this study, two laboratory scale MDCs having three chambered (3C-MDC) and five chambered (5C-MDC) configuration were developed for integrated biodegradation of steel plant wastewater. The 3C-MDC have anodic, middle desalination and cathodic chamber; while 5C-MDC have anodic, cathodic, middle desalination and two concentrate chambers separated by ion exchange membranes. Using synthetic saline water with 8 and 30 g/L of TDS and steel plant wastewater (3.74 g TDS/L) in desalination chamber, the TDS removal of 64 ± 2.3%, 75 ± 1.8%, and 58 ± 1.3% were observed in 3C-MDC, while in 5C-MDC, those were 58 ± 1.5%, 71 ± 2.1%, and 64 ± 2.4%, respectively in 96 h of fed batch operation. With 30 g/L of TDS concentration, the power generation observed in 3C-MDC and 5C-MDCs were (81 mW/m2 and 78 mW/m2) higher than the power observed with 8 g/L (56 mW/m2 and 45 mW/m2). However, with steel plant wastewater in desalination chamber the power density increased to 76 mW/m2 in 5C-MDC and significantly decreased to 39 mW/m2 in 3C-MDC.
Gold Biodissolution from Electronic Scrap and Biomineralization of Bacterial Gold Nanoparticles
Authors: Das Subhabrata , Dong Bin , Ting Yen Peng
Published: December 2015

Gold nanoparticles (GNPs) have shown great promises in biomedical applications due to their distinct dimensions, non-toxicity, regulated drug release capability and adjustable surface functionalities. This study illustrates a green method for GNPs synthesis from electronic scrap material (ESM) usingCupriavidus metalliduransandDelftia acidovorans.Leaching of pre-treated electronic scrap materials at 0.5 % (w/v) pulp density using spent medium genetically from modifiedChromobacterium violaceumpBAD strain recovered 37.8% of gold. The recovered gold in solution was converted in GNPs usingC. metalliduransandD. acidovorans. The synthesized GNPs were mostly spherical in shape and crystalline in nature.
Adsorption and Desorption Potential of Cadmium Using Green Algae: Equilibrium and Kinetic Studies
Authors: Birungi Z.S. , Chirwa E.M.N.
Published: December 2015

Microalgae has a diversity of species found in freshwater bodies but only a few have been explored for their biosorption potential as compared to macro algae (sea weed). Equilibrium and kinetic experiments were used to estimate sorption capacity and rate of reaction respectively. Chloroidium saccharophilum had the highest sorption capacity (qmax) of 200 mg/g and lower affinity (b) of 0.0095 L/g for removal of Cd. However, Stichococcus bacillaris was the best adsorbent for Cd as it had both a higher qmaxand higher b of 125 and 0.049 L/g. The Langmuir and Pseudo-second order models performed better than the Freundlich and First-order models with a regression coefficient (R2) > 0.9. Adsorption and desorption efficiency was achieved highest for Stichococcus bacillaris at 95.8% and 73.49% respectively.
The Production of Soluble Ferric Sulfate via Biological and Chemical Processing of Iron Sulfides
Authors: Dreisinger David , Dreisinger Amanda , Dreisinger Caleb
Published: December 2015

Ferric sulfate is a very useful reagent for mineral leaching and metal recovery. Ferric sulfate may be used as an oxidative leaching agent for uranium, zinc, copper, nickel and other ores. Ferric ion is a modestly strong oxidant. Similarly, the use of ferric co-precipitation to stabilize arsenic, selenium and other species is in wide use. The demand for ferric sulfate for this application is increasing. Pyrite and pyrrhotite represent minerals that are widely available as sources of soluble iron to provide ferric sulfate for leaching and for iron co-precipitation. The use of biological processes for oxidation of pyrite is well established. However, the common goal is to use biological oxidation to liberate a valuable material (eg. Gold locked in arsenopyrite or pyrite). Much less attention has been paid to production of soluble iron for leaching of other minerals or for use as a precipitant. The use of chemical processes such as atmospheric and pressure oxidation may also be used to generate ferric sulfate from iron sulfide minerals. In this paper the use of biological and chemical processing for production of ferric sulfate will be reviewed and discussed.
Apparent Absence of Microbial Life inside an Alkaline Slag Dump
Authors: Schippers Axel , Rammlmair Dieter
Published: December 2015

An extremely alkaline slag dump in Germany was investigated for its mineralogy and colonization with microorganisms. The dump material originated from a metallurgical processing plant for steel production and consisted of a magnetic concentrate of cohenite, metallic iron and magnetite interwoven or associated with various slag related phases such as glasses of variable chemistry, RO-, C2F- and C4AF- phases, and phases originating from the ovens, steel additives, sand and construction fragments. After deposition, reactions in the surface layer generated a number of secondary phases such as gels (NaCO3-rich or -poor), calcite, mirabilite, natron, and others. To explore the microbiology inside the approximately 15 m high dump, 35 samples were taken over the whole depth range via core drilling. Total cell counts were determined via acridine orange staining and living cells were enumerated on R2 agar plates for heterotrophs. Both methods allowed for the detection of microbial life on the dump surface down to about 1 m depth. In this depth range the pH values were between 8 and 12. Below, microbial life was not detected, most likely because of the high pH values of 12 and the low availability of organic carbon inside the dump. In contrast to all previously studied sulfidic dumps the interior of the alkaline slag dump did not appear to be a habitat for microorganisms.
A First Principle Approach to Design Gated p-i-n Nanodiode
Authors: Dey Debarati , Roy Pradipta , Purkayastha Tamoghna , De Debashis
Published: December 2015

Thanks to the world of nanotechnology; it is possible to build molecular nanodevices. In this paper, GaAs single nanowire molecular p-i-n diode is designed and its electronic transmission properties, Local Device Density of States, Highest Occupied Molecular Orbital-Lowest Unoccupied Molecular Orbital plot and Negative Differential Resistance property are investigated from the atomic perspective using first principle Density Functional Theory-Non Equilibrium Green Function approach. This molecular structure is built and simulated in Virtual nanoLab atmosphere. The Negative Differential Resistance of the device is revealed through the current-voltage characteristics of the nanowire. The band-to-band tunneling current is observed for this p-i-n junction nanodiode. Thermal coefficient, Peltier co-efficient, and Seebeck coefficients at different gate bias are obtained. This nanowire GaAs molecular diode is attractive for the next generation low power nanodevice design. Electrical doping effect has been introduced in the wire without adding unambiguous dopants to the molecular wire.
Effects of prey resource fluctuation on predation attributes of two sympatric Coccinellidae (Coleoptera)
Authors: Chaudhary Desh Deepak , Kumar Bhupendra , Mishra Geetanjali , Omkar
Published: December 2015

Under natural conditions, prey resources may fluctuate considerably in space and time; and predators are continuously faced with challenges of resource availability and use. In this study, effects of fluctuations (scarce/optimal/abundant) in biomass of pea aphid (Acyrthosiphon pisum (Harris); Hemiptera: Aphididae) during rearing and experimental conditions on certain predatory attributes (consumption rate/conversion, efficiency/growth rate) of two sympatric aphidophagous Coccinellidae (Coleoptera) were evaluated. Results revealed significant influence of rearing conditions on conversion efficiency and growth rate; and experimental conditions on all three predation attributes of Menochilus sexmaculatus (Fabricius) (Coleoptera: Coccinellidae). Larvae/adults of M. sexmaculatus had similar consumption rates per rearing condition, but exhibited highest and lowest consumption rates when abruptly shifted to abundant and scarce prey experimental conditions. Further, scarce prey reared larvae/adults of M. sexmaculatus displayed highest conversion efficiency and growth rate on optimal/abundant prey experimental condition(s). However, all three predation attributes of larvae/adults of Propylea dissecta (Mulsant) (Coleoptera: Coccinellidae) were influenced substantially by both the rearing and experimental conditions; and scarce prey reared larvae/adults exhibited highest predation attributes on optimal/abundant prey experimental condition(s). Moreover, predation attributes of M. sexmaculatus were higher than P. dissecta on the three experimental conditions. Therefore, this study suggests that M. sexmaculatus has a better compensatory ability to overcome prey resource fluctuation than P. dissecta.
Report of activities for the Core Zone and bounding orogens: The New Quebec Orogen and its relationship with the Core Zone in the Kuujjuaq area
Authors: Corrigan D , Van Rooyen D , Morin A , Houlé M G , McNicoll V J
Published: December 2015

Foreword
The Geo-mapping for Energy and Minerals (GEM) program is laying the foundation for sustainable economic development in the North. The Program provides modern public geoscience that will set the stage for long-term decision making related to investment in responsible resource development. Geoscience
knowledge produced by GEM supports evidence-based exploration for new energy and mineral resources and enables northern communities to make informed decisions about their land, economy and society. Building upon the success of its first five-years, GEM has been renewed until 2020 to continue
producing new, publically available, regional-scale geoscience knowledge in Canada's North.
During the summer of 2015, the GEM program successfully carried out 17 research activities that include geological, geochemical and geophysical surveying. These activities have been undertaken in collaboration with provincial and territorial governments, northerners and their institutions, academia
and the private sector. GEM will continue to work with these key collaborators as the program advances.
Иерархии конечномерных уравнений Лакса со спектральным параметром на римановой поверхности и полупростые алгебры Ли
Authors: Sheinman Oleg Karlovich
Published: December 2015

Исходя из $\mathbb Z$-градуировок полупростых алгебр Ли и инвариантных полиномов на последних построены иерархии уравнений Лакса со спектральным параметром на римановой поверхности. Доказана коммутативность соответствующих потоков.
Колчанные переменные и квантовые уравнения Книжника-Замолодчикова
Authors: Zinn-Justin Paul
Published: December 2015

Показано, как эквивариантные объемы тензорных произведений колчанных переменных типа A задаются матричными элементами вершинных операторов центрально расширенных янгианных дублей и как эти элементы удовлетворяют в некоторых случаях рациональному квантовому уравнению Книжника-Замолодчикова уровня один.
Твистованные множества характеров, накрывающие пространства и пучки
Authors: Wu Siye
Published: December 2015

Для подгруппы $\widetilde\Pi$ конечного индекса конечнопорожденной группы $\Pi$ установлены различные соотношения между (твистованными) множествами характеров групп $\Pi$ и $\widetilde\Pi$. Дана геометрическая интерпретация результатов в терминах пространств модулей плоских связностей на главных расслоениях, твистованных пучком плоской связности над многообразием с фундаментальной группой $\Pi$.
Enhanced Diagnosis of Pneumococcal Bacteremia Using Antigen- and Molecular-Based Tools on Blood Specimens in Mali and Thailand: A Prospective Surveillance Study
Authors: Moïsi Jennifer C. , Moore Matthew , Carvalho Maria da Gloria , Sow Samba O. , Siludjai Duangkamon , Knoll Maria Deloria , Tapia Milagritos , Baggett Henry C. , _ _
Published: December 2015

Prior antibiotic use, contamination, limited blood volume, and processing delays reduce yield of blood cultures for detection of Streptococcus pneumoniae. We performed immunochromatographic testing (ICT) on broth from incubated blood culture bottles and real-time lytA polymerase chain reaction (PCR) on broth and whole blood and compared findings to blood culture in patients with suspected bacteremia. We selected 383 patients in Mali and 586 patients in Thailand based on their blood culture results: 75 and 31 were positive for pneumococcus, 100 and 162 were positive for other pathogens, and 208 and 403 were blood culture negative, respectively. ICT and PCR of blood culture broth were at least 87% sensitive and 97% specific compared with blood culture; whole blood PCR was 75–88% sensitive and 96–100% specific. Pneumococcal yields in children < 5 years of age increased from 2.9% to 10.7% in Mali with > 99% of additional cases detected by whole blood PCR, and from 0.07% to 5.1% in Thailand with two-thirds of additional cases identified by ICT. Compared with blood culture, ICT and lytA PCR on cultured broth were highly sensitive and specific but their ability to improve pneumococcal identification varied by site. Further studies of these tools are needed before widespread implementation.
Chikungunya Virus Sequences Across the First Epidemic in Nicaragua, 2014–2015
Authors: Wang Chunling , Saborio Saira , Gresh Lionel , Eswarappa Meghana , Wu Diane , Fire Andrew , Parameswaran Poornima , Balmaseda Angel , Harris Eva
Published: December 2015

Chikungunya is caused by the mosquito-borne arthrogenic alphavirus, chikungunya virus (CHIKV). Chikungunya was introduced into the Americas in late 2013 and Nicaragua in mid-2014. Here, we sequenced five imported and 30 autochthonous Nicaraguan CHIKV from cases identified in the first epidemic in the country between August 2014 and April 2015. One full-length and two partial genomic sequences were obtained by deep sequencing; Sanger methodology yielded 33 E1 sequences from five imported and 28 autochthonous cases. Phylogenetic analysis indicates that Nicaraguan CHIKV all belonged to the Asian genotype, Caribbean clade. Moreover, E1 gene sequences revealed accumulation of mutations in later months of the epidemic, including four silent mutations in 11 autochthonous cases and three non-synonymous mutations in three autochthonous cases. No mutations contributing to increased transmissibility by Aedes albopictus were identified in the E1 gene. This represents the most comprehensive set of CHIKV sequences available from the Americas to date.
Clinical and Epidemiological Characterization of the First Recognized Outbreak of Dengue Virus-Type 2 in Mozambique, 2014
Authors: Massangaie Marilia , Pinto Gabriela , Padama Fernando , Chambe Geraldo , da Silva Mariana , Mate Inocêncio , Chirindza Celia , Ali Sadia , Agostinho Sãozinha , Chilaule Daniel , Weyer Jacqueline , le Roux Chantel , Abilio Ana Paula , Baltazar Cynthia , Doyle Timothy J. , Cliff Julie , Paweska Janusz , Gudo Eduardo Samo
Published: December 2015

Since the first reported epidemic of dengue in Pemba, the capital of Cabo Delgado province, in 1984–1985, no further cases have been reported in Mozambique. In March 2014, the Provincial Health Directorate of Cabo Delgado reported a suspected dengue outbreak in Pemba, associated with a recent increase in the frequency of patients with nonmalarial febrile illness. An investigation conducted between March and June detected a total of 193 clinically suspected dengue patients in Pemba and Nampula, the capital of neighboring Nampula Province. Dengue virus-type 2 (DENV-2) was detected by reverse transcriptase polymerase chain reaction in sera from three patients, and 97 others were classified as probable cases based on the presence of DENV nonstructural protein 1 antigen or anti-DENV immunoglobulin M antibody. Entomological investigations demonstrated the presence of Aedes aegypti mosquitos in both Pemba and Nampula cities.
Observations of the spectral dependence of linear particle depolarization ratio of aerosols using NASA Langley airborne High Spectral Resolution Lidar
Authors: Burton S. P. , Hair J. W. , Kahnert M. , Ferrare R. A. , Hostetler C. A. , Cook A. L. , Harper D. B. , Berkoff T. A. , Seaman S. T. , Collins J. E. , Fenn M. A. , Rogers R. R.
Published: December 2015

Abstract. Linear particle depolarization ratio is presented for three case studies from the NASA Langley airborne High Spectral Resolution Lidar-2 HSRL-2). Particle depolarization ratio from lidar is an indicator of non-spherical particles and is sensitive to the fraction of non-spherical particles and their size. The HSRL-2 instrument measures depolarization at three wavelengths: 355, 532, and 1064 nm. The three measurement cases presented here include two cases of dust-dominated aerosol and one case of smoke aerosol. These cases have partial analogs in earlier HSRL-1 depolarization measurements at 532 and 1064 nm and in literature, but the availability of three wavelengths gives additional insight into different scenarios for non-spherical particles in the atmosphere. A case of transported Saharan dust has a spectral dependence with a peak of 0.30 at 532 nm with smaller particle depolarization ratios of 0.27 and 0.25 at 1064 and 355 nm, respectively. A case of aerosol containing locally generated wind-blown North American dust has a maximum of 0.38 at 1064 nm, decreasing to 0.37 and 0.24 at 532 and 355 nm, respectively. The cause of the maximum at 1064 nm is inferred to be very large particles that have not settled out of the dust layer. The smoke layer has the opposite spectral dependence, with the peak of 0.24 at 355 nm, decreasing to 0.09 and 0.02 at 532 and 1064 nm, respectively. The depolarization in the smoke case may be explained by the presence of coated soot aggregates. We note that in these specific case studies, the linear particle depolarization ratio for smoke and dust-dominated aerosol are more similar at 355 nm than at 532 nm, having possible implications for using the particle depolarization ratio at a single wavelength for aerosol typing.
Degree of ice particle surface roughness inferred from polarimetric observations
Authors: Hioki S. , Yang P. , Baum B. A. , Platnick S. , Meyer K. G. , King M. D. , Riedi J.
Published: December 2015

Abstract. The degree of surface roughness of ice particles within thick, cold ice clouds is inferred from multi-directional, multi-spectral satellite polarimetric observations over oceans, assuming a column-aggregate particle habit. An improved roughness inference scheme is employed in the analysis that provides a more noise-resilient roughness estimate than the conventional best-fit approach. The improvements include the introduction of a quantitative roughness parameter based on empirical orthogonal function analysis and proper treatment of polarization due to atmospheric scattering above clouds. A global one-month data sample supports the use of a severely roughened ice habit to simulate the polarized reflectivity associated with ice clouds over ocean. The density distribution of the roughness parameter inferred from the global one-month data sample and further analyses of a few case studies demonstrate the significant variability of ice cloud single-scattering properties. The present theoretical results are in close agreement with observations in the extratropics but not in the tropics. Potential improvements are discussed to enhance the depiction of the natural variability on a global scale.
Lidar-Radiometer Inversion Code (LIRIC) for the retrieval of vertical aerosol properties from combined lidar/radiometer data: development and distribution in EARLINET
Authors: Chaikovsky A. , Dubovik O. , Holben B. , Bril A. , Goloub P. , Tanré D. , Pappalardo G. , Wandinger U. , Chaikovskaya L. , Denisov S. , Grudo Y. , Lopatin A. , Karol Y. , Lapyonok T. , Amiridis V. , Ansmann A. , Apituley A. , Allados-Arboledas L. , Binietoglou I. , Boselli A. , D'Amico G. , Freudenthaler V. , Giles D. , Granados-Muñoz M. J. , Kokkalis P. , Nicolae D. , Oshchepkov S. , Papayannis A. , Perrone M. R. , Pietruczuk A. , Rocadenbosch F. , Sicard M. , Slutsker I. , Talianu C. , De Tomasi F. , Tsekeri A. , Wagner J. , Wang X.
Published: December 2015

Abstract. This paper presents a detailed description of LIRIC (LIdar-Radiometer Inversion Code) algorithm for simultaneous processing of coincident lidar and radiometric (sun photometric) observations for the retrieval of the aerosol concentration vertical profiles. As the lidar/radiometric input data we use measurements from European Aerosol Research Lidar Network (EARLINET) lidars and collocated sun-photometers of Aerosol Robotic Network (AERONET). The LIRIC data processing provides sequential inversion of the combined lidar and radiometric data by the estimations of column-integrated aerosol parameters from radiometric measurements followed by the retrieval of height-dependent concentrations of fine and coarse aerosols from lidar signals using integrated column characteristics of aerosol layer as a priori constraints. The use of polarized lidar observations allows us to discriminate between spherical and non-spherical particles of the coarse aerosol mode. The LIRIC software package was implemented and tested at a number of EARLINET stations. Intercomparison of the LIRIC-based aerosol retrievals was performed for the observations by seven EARLNET lidars in Leipzig, Germany on 25 May 2009. We found close agreement between the aerosol parameters derived from different lidars that supports high robustness of the LIRIC algorithm. The sensitivity of the retrieval results to the possible reduction of the available observation data is also discussed.
Stable isotope study of a new chondrichthyan fauna (Kimmeridgian, Porrentruy, Swiss Jura): an unusual freshwater-influenced isotopic composition for the hybodont shark Asteracanthus
Authors: Leuzinger L. , Kocsis L. , Billon-Bruyat J.-P. , Spezzaferri S. , Vennemann T.
Published: December 2015

Abstract. Chondrichthyan teeth (sharks, rays, and chimaeras) are mineralized in isotopic equilibrium with the surrounding water, and parameters such as water temperature and salinity can be inferred from the oxygen isotopic composition (δ18Op) of their bioapatite. We analysed a new chondrichthyan assemblage, as well as teeth from bony fish (Pycnodontiformes). All specimens are from Kimmeridgian coastal marine deposits of the Swiss Jura (vicinity of Porrentruy, Ajoie district, NW Switzerland). While the overall faunal composition and the isotopic composition of bony fish are generally consistent with marine conditions, unusually low δ18Op values were measured for the hybodont shark Asteracanthus. These values are also lower compared to previously published data from older European Jurassic localities. Additional analyses on material from Solothurn (Kimmeridgian, NW Switzerland) also have comparable, low-18O isotopic compositions for Asteracanthus. The data are hence interpreted to represent a so far unique, freshwater-influenced isotopic composition for this shark that is classically considered a marine genus. While reproduction in freshwater or brackish realms is established for other hybodonts, a similar behaviour for \\textit{Asteracanthus} is proposed here. Regular excursions into lower salinity waters can be linked to the age of the deposits and correspond to an ecological adaptation, most likely driven by the Kimmeridgian transgression and by the competition of the hybodont shark Asteracanthus with the rapidly diversifying neoselachians (modern sharks).
Impact of forest harvesting on water quality and fluorescence characteristics of dissolved organic matter in eastern Canadian Boreal Shield lakes in summer
Authors: Glaz P. , Gagné J.-P. , Archambault P. , Sirois P. , Nozais C.
Published: December 2015

Abstract. Forestry activities in the Canadian Boreal region have increased in the last decades, raising concerns about their potential impact on aquatic ecosystems. Water quality and fluorescence characteristics of dissolved organic matter (DOM) were measured over a 3-year period in eight eastern Boreal Shield lakes: four lakes were studied before, 1 and 2 years after forest harvesting (perturbed lakes) and compared with four undisturbed reference lakes (unperturbed lakes) sampled at the same time. ANOVAs showed a significant increase in total phosphorus (TP) in perturbed lakes when the three sampling dates were considered and in DOC concentrations when considering 1 year before and 1 year after the perturbation only. At 1 year post-clear cutting DOC concentrations were about 15 % greater in the perturbed lakes at ~ 15 mgC L−1 compared to 12.5 mgC L−1 in the unperturbed lakes. In contrast, absorbance and fluorescence measurements showed that all metrics remained within narrow ranges compared to the range observed in natural waters, indicating that forest harvesting did not affect the nature of DOM characterized with spectroscopic techniques. These results confirm an impact of forestry activities 1 year after the perturbation. However, this effect seems to be mitigated 2 years after, indicating that the system shows high resilience and may be able to return to its original condition in terms of water quality parameters assessed in this study.
Carbon dynamics in boreal peatlands of the Yenisey region, western Siberia
Authors: Schulze E. D. , Lapshina E. , Filippov I. , Kuhlmann I. , Mollicone D.
Published: December 2015

Abstract. Here we investigate the vegetation history and peat accumulation at the eastern boarder of the West Siberian Plain, near the Yenisey River, south of permafrost. In this region, peat started to accumulate 15 000 years ago as gyttja of shallow lakes in ancient river valleys. This peat is older than previously reported, mainly due to separating particulate organic carbon (POC) from dissolved organic carbon (DOC), which was 1900–6500 years younger than POC. The probability of finding peat layers older than 12 000 years is about 2 %. Peat accumulated as fen peat at a constant rate of 0.2 mm yr−1 and 0.01 kg C m−2 yr−1. The accumulation was higher in ancient river valley environments. Over the last 2000 years these bogs changed into Sphagnum mires which have accumulated up to about 0.1 kg C m−2 yr−1 until present. The long-lasting fen stage, which makes the Yenisey bogs distinct from the western Siberian bogs, is discussed as a consequence of the local hydrology. The high accumulation rate of peat in unfrozen mires is taken as an indication that thawing of permafrost peat may also change northern peatlands into long-lasting carbon sinks.
The contribution of trees and grasses to productivity of an Australian tropical savanna
Authors: Moore C. E. , Beringer J. , Evans B. , Hutley L. B. , McHugh I. , Tapper N. J.
Published: December 2015

Abstract. Savanna ecosystems cover 20 % of the global land surface and account for 25 % of global terrestrial carbon uptake. They support one fifth of the world's human population and are one of the most important ecosystems on our planet. Savanna productivity is a product of the interplay between trees and grass that co-dominate savanna landscapes and are maintained through interactions with climate and disturbance (fire, land use change, herbivory). In this study, we evaluate the temporally dynamic partitioning of overstory and understory carbon dioxide fluxes in Australian tropical savanna using overstory and understory eddy covariance measurements. Over a two year period (September 2012 to October 2014) the overall net ecosystem productivity (NEP) of the savanna was 506.2 (±22 SE) g C m−2 yr−1. The total gross primary productivity (GPP) was 2267.1 (±80 SE) g C m−2 yr−1, of which the understory contributed 32 %. The understory contribution was strongly seasonal, with most GPP occurring in the wet season (40 % of total ecosystem in the wet season and 18 % in the dry). This study is the first to elucidate the temporal dynamics of savanna understory and overstory carbon flux components explicitly using observational information. Understanding grass productivity is crucial for evaluating fuel loads, as is tree productivity for quantifying the tree carbon sink. This information will contribute to a significant refinement of the representation of savannas in models, as well as improved understanding of relative tree-grass productivity and competition for resources.
Windthrows increase soil carbon stocks in a Central Amazon forest
Authors: dos Santos L. T. , Magnabosco Marra D. , Trumbore S. , Camargo P. B. , Chambers J. Q. , Negrón-Juárez R. I. , Lima A. J. N. , Ribeiro G. H. P. M. , dos Santos J. , Higuchi N.
Published: December 2015

Abstract. Windthrows change forest structure and species composition in Central Amazon forests. However, the effects of widespread tree mortality associated with wind-disturbances on soil properties have not yet been described. In this study, we investigated short-term effects (seven years after disturbance) of a windthrow event on soil carbon stocks and concentrations in a Central Amazon terra firme forest. The soil carbon stock (averaged over a 0–30 cm depth profile) in disturbed plots (61.4 ± 4.18 Mg ha−1, mean ± standard error) was marginally higher (p = 0.009) than that from undisturbed plots (47.7 ± 6.95 Mg ha−1). The soil organic carbon concentration in disturbed plots (2.0 ± 0.08 %) was significantly higher (p < 0.001) than that from undisturbed plots (1.36 ± 0.12 %). Moreover, soil carbon stocks were positively correlated with soil clay content (r = 0.575 and p = 0.019) and with tree mortality intensity (r = 0.493 and p = 0.045). Our results indicate that large inputs of plant litter associated with large windthrow events cause a short-term increase in soil carbon content, and the degree of increase is related to soil clay content and tree mortality intensity. Higher nutrient availability in soils from large canopy gaps created by wind disturbance may increase vegetation resilience and favor forest recovery.
Expansion and diversification of high-latitude radiolarian assemblages in the late Eocene linked to a cooling event in the southwest Pacific
Authors: Pascher K. M. , Hollis C. J. , Bohaty S. M. , Cortese G. , McKay R. M. , Seebeck H. , Suzuki N. , Chiba K.
Published: December 2015

Abstract. The long-term cooling trend from middle to late Eocene was punctuated by several large-scale climate perturbations that culminated in a shift to "icehouse" climates at the Eocene–Oligocene transition. We present radiolarian micro-fossil assemblage and foraminiferal oxygen and carbon stable isotope data from Deep Sea Drilling Project (DSDP) sites 277, 280, 281, and 283 and Ocean Drilling Project (ODP) Site 1172 to identify significant oceanographic changes in the southwest Pacific through this climate transition (~ 40–30 Ma). We find that the Middle Eocene Climatic Optimum at ~ 40 Ma, which is truncated but identified by a negative shift in foraminiferal δ18O values at Site 277, is associated with a small increase in radiolarian taxa with low-latitude affinities (5 % of total fauna). In the early late Eocene at ~ 37 Ma, a positive oxygen isotope shift at Site 277 is correlated with the Priabonian Oxygen Isotope Maximum (PrOM). Radiolarian abundance, diversity, and preservation increase within this cooling event at Site 277 at the same time as diatom abundance. A negative δ18O excursion above the PrOM is correlated with a late Eocene warming event (~ 36.4 Ma). Radiolarian abundance and diversity decline within this event and taxa with low-latitude affinities reappear. Apart from this short-lived warming event, the PrOM and latest Eocene radiolarian assemblages are characterised by abundant high-latitude taxa. High-latitude taxa are also abundant during the late Eocene and early Oligocene (~ 38–30 Ma) at DSDP sites 280, 281, 283 and 1172 and are associated with very high diatom abundance. We therefore infer a northward expansion of high-latitude radiolarian taxa onto the Campbell Plateau in the latest Eocene. In the early Oligocene there is an overall decrease in radiolarian abundance and diversity at Site 277, and diatoms are scarce. These data indicate that, once the Antarctic Circumpolar Current was established in the early Oligocene (~ 30 Ma), a frontal system similar to present day developed, with nutrient-depleted Subantarctic waters bathing the area around DSDP Site 277, resulting in a more restricted siliceous plankton assemblage.
South Asia river-flow projections and their implications for water resources
Authors: Mathison C. , Wiltshire A. J. , Falloon P. , Challinor A. J.
Published: December 2015

Abstract. South Asia is a region with a large and rising population, a high dependence on water intense industries, such as agriculture and a highly variable climate. In recent years, fears over the changing Asian summer monsoon (ASM) and rapidly retreating glaciers together with increasing demands for water resources have caused concern over the reliability of water resources and the potential impact on intensely irrigated crops in this region. Despite these concerns, there is a lack of climate simulations with a high enough resolution to capture the complex orography, and water resource analysis is limited by a lack of observations of the water cycle for the region. In this paper we present the first 25 km resolution regional climate projections of river flow for the South Asia region. Two global climate models (GCMs), which represent the ASM reasonably well are downscaled (1960–2100) using a regional climate model (RCM). In the absence of robust observations, ERA-Interim reanalysis is also downscaled providing a constrained estimate of the water balance for the region for comparison against the GCMs (1990–2006). The RCM river flow is routed using a river-routing model to allow analysis of present-day and future river flows through comparison with available river gauge observations. We examine how useful these simulations are for understanding potential changes in water resources for the South Asia region. In general the downscaled GCMs capture the seasonality of the river flows but overestimate the maximum river flows compared to the observations probably due to a positive rainfall bias and a lack of abstraction in the model. The simulations suggest an increasing trend in annual mean river flows for some of the river gauges in this analysis, in some cases almost doubling by the end of the century. The future maximum river-flow rates still occur during the ASM period, with a magnitude in some cases, greater than the present-day natural variability. Increases in river flow could mean additional water resources for irrigation, the largest usage of water in this region, but has implications in terms of inundation risk. These projected increases could be more than countered by changes in demand due to depleted groundwater, increases in domestic use or expansion of water intense industries. Including missing hydrological processes in the model would make these projections more robust but could also change the sign of the projections.
GB-InSAR monitoring and observational method for landslide emergency management: the Montaguto earthflow (AV, Italy)
Authors: Ferrigno F. , Gigli G. , Fanti R. , Casagli N.
Published: December 2015

Abstract. On 10 March 2010, due to the heavy rainfall that occurred on the previous days, the Montaguto earthflow reactivated, involving the road SS 90 "Delle Puglie", as had happened previously in May 2005 and in September 2009, and reaching the Roma–Bari railway. This determined a special attention of the National Civil Protection Department and a widespread monitoring and analysis program was initiated. A monitoring activity using GB-InSAR (Ground Based Interferometric Synthetic Aperture Radar) system began, in order to investigate the landslide kinematics, to plan urgent safety measures for risk mitigation and to design long term stabilization work. In this paper the GB-InSAR monitoring system results and its applications in the Observational Method (OM) approach are presented. The paper also highlights how the OM based on the GB-InSAR technique can produce savings in cost and time on engineering projects, without compromising safety, and how it can also benefit the geotechnical community by increasing scientific knowledge. This study focuses on the very much active role played by the monitoring activities, in both the design and plan modifications; with a special consideration for the emergency phase.
A local particle filter for high dimensional geophysical systems
Authors: Penny S. G. , Miyoshi T.
Published: December 2015

Abstract. A local particle filter (LPF) is introduced that outperforms traditional ensemble Kalman filters in highly nonlinear/non-Gaussian scenarios, both in accuracy and computational cost. The standard Sampling Importance Resampling (SIR) particle filter is augmented with an observation-space localization approach, for which an independent analysis is computed locally at each gridpoint. The deterministic resampling approach of Kitagawa is adapted for application locally and combined with interpolation of the analysis weights to smooth the transition between neighboring points. Gaussian noise is applied with magnitude equal to the local analysis spread to prevent particle degeneracy while maintaining the estimate of the growing dynamical instabilities. The approach is validated against the Local Ensemble Transform Kalman Filter (LETKF) using the 40-variable Lorenz-96 model. The results show that: (1) the accuracy of LPF surpasses LETKF as the forecast length increases (thus increasing the degree of nonlinearity), (2) the cost of LPF is significantly lower than LETKF as the ensemble size increases, and (3) LPF prevents filter divergence experienced by LETKF in cases with non-Gaussian observation error distributions.
Technical note: Could benzalkonium chloride be a suitable alternative to mercuric chloride for preservation of seawater samples?
Authors: Gloël J. , Robinson C. , Tilstone G. H. , Tarran G. , Kaiser J.
Published: December 2015

Abstract. Instrumental equipment unsuitable or unavailable for fieldwork as well as lack of ship space can necessitate the preservation of seawater samples prior to analysis in a shore-based laboratory. Mercuric chloride (HgCl2) is routinely used for such preservation, but its handling and subsequent disposal incur environmental risks and significant expense. There is therefore a strong motivation to find less hazardous alternatives. Benzalkonium chloride (BAC) has been used previously as microbial inhibitor for freshwater samples. Here, we assess the use of BAC for marine samples prior to the measurement of oxygen-to-argon (O2 / Ar) ratios, as used for the determination of biological net community production. BAC at a concentration of 50 mg dm−3 inhibited microbial activity for at least 3 days in samples tested with chlorophyll a (Chl a) concentrations up to 1 mg m−3. BAC concentrations of 100 and 200 mg dm−3 were no more effective than 50 mg dm−3. With fewer risks to human health and the environment, and no requirement for expensive waste disposal, BAC could be a viable alternative to HgCl2 for short-term preservation of seawater samples, but is not a replacement for HgCl2 in the case of oxygen triple isotope analysis, which requires storage over weeks to months. In any event, further tests on a case-by-case basis should be undertaken if use of BAC was considered, since its inhibitory activity may depend on concentration and composition of the microbial community.