bluuebunny/crossref_metadata_2025 huggingface dataset:
Social Constructions of GIS in China's Changing Urban Governance: The Case of Shenzhen
Authors: Lin Wen , Ghose Rina
Published: June 2010

GIS technologies have developed rapidly in urban China, particularly within local governments, over the past decade. However, such GIS practices in non-Western contexts have not been investigated in depth. The present study attempts to address this gap, drawing on insights from critical GIS and political economy. Scholarship in critical GIS has underlined the importance of power relations in constituting organizational GIS practices, and vice versa. Moreover, perspectives from scalar politics and network analysis provide a useful way to delineate and analyse the spatialized social relations shaping and embedded in GIS constructions. In particular, scaled networks conceptualize social connections and power relations in terms of networks of actors embedded in different spatial extents; within this synthesized framework, we contend, local government organizations serve as both sites and nodes in developing and employing GIS. Through an in-depth case study of the city of Shenzhen, we investigate in what ways both territorial conditions and interrelations across organizational and city boundaries influence governmental GIS development. Such an investigation helps to politicize the constructions of GIS in China's changing urban governance, which will contribute to ongoing discussions in critical GIS aimed at understanding the mutual constitution of GIS and society.
Freud in Trieste: Journey to an Ambiguous City
Authors: Gandolfi Laura
Published: June 2010

This article provides an insightful exploration of the relationship between Sigmund Freud and the city of Trieste. Through an analysis of the correspondence between Freud and his friend Eduard Silberstein, Gandolfi follows those places visited by the future father of psychoanalysis and analyses their link to Freud's life. The journey to Trieste is considered as an experience that played a fundamental role in his future decisions as well as in the development of some of his psychoanalytic theories. The article eventually relates the ambiguous nature of the city – a peculiar space in which North and South, East and West converge – to Freud's own Triestine experience, that not only remits to his initial scientific researches, but also symbolizes a first significant contact with the world of sexuality.
Towards a History of Operatic Psychoanalysis
Authors: Carpenter Alexander
Published: June 2010

This paper examines the history of the trope of psychoanalytic therapy in musical dramas, from Richard Wagner to Kurt Weill, concluding that psychoanalysis and the musical drama are, in some ways, companions and take cues from each other, beginning in the mid-19th century. In Wagner's music dramas, psychoanalytic themes and situations – specifically concerning the meaning and analysis of dreams – are presaged. In early modernist music dramas by Richard Strauss and Arnold Schoenberg (contemporaries of Freud), tacit representations of the drama of hysteria, its aetiology and ‘treatment’ comprise key elements of the plot and resonate with dissonant musical soundscapes. By the middle of the 20th century, Kurt Weill places the relationship between analyst and patient in the foreground of his musical Lady in the Dark, thereby making manifest what is latent in a century-spanning chain of musical works whose meaning centres, in part, around representations of psychoanalysis.
How Sex Became Gender
Authors: Nye Robert A.
Published: June 2010

This article argues that ‘sex’ which had been commonly assumed in the West to refer to a permanent set of biological and behavioural traits particular to men and women, is gradually being replaced in general usage by ‘gender’. Though feminist theorists attempted to attach a constructivist meaning to gender, a generation of developmental theorists, clinicians and analysts has imbued the term with the determinism and biological qualities formerly ascribed to ‘sex’. The triumph of this materialist conception of gender is not assured, but it threatens our ability to think about gender identity as a historically-constructed category.
Information – A New Open Access Scientific Journal on Information Science, Information Technology, Data, Knowledge and Communication
Authors: Lin Shu-Kun
Published: June 2010

We plan to expand our Open Access publishing project to encompass additional fundamental areas in science and technology and to provide publication opportunities for scientists working in these areas. To achieve these goals, we are in the process of launching new journals. [...]
Research and Application of Marine Microbial Enzymes: Status and Prospects
Authors: Zhang Chen , Kim Se-Kwon
Published: June 2010

Over billions of years, the ocean has been regarded as the origin of life on Earth. The ocean includes the largest range of habitats, hosting the most life-forms. Competition amongst microorganisms for space and nutrients in the marine environment is a powerful selective force, which has led to evolution. The evolution prompted the marine microorganisms to generate multifarious enzyme systems to adapt to the complicated marine environments. Therefore, marine microbial enzymes can offer novel biocatalysts with extraordinary properties. This review deals with the research and development work investigating the occurrence and bioprocessing of marine microbial enzymes.
Experimental Test of L- and D-Amino Acid Binding to L- and D-Codons Suggests that Homochirality and Codon Directionality Emerged with the Genetic Code
Authors: Root-Bernstein Robert
Published: June 2010

L-amino acids bind preferentially to their D-codons, but almost nothing is known about whether D-amino acids correspondingly prefer L-codons, or how codon directionality affects amino acid binding. To investigate these issues, two D-RNA-oligonucleotides having inverse base sequences (D-CGUA and D-AUGC) and their corresponding L-RNA-oligonucleotides (L-CGUA and L-AUGC) were synthesized and their affinity determined for Gly and eleven pairs of L- and D-amino acids. The data support the hypothesis (Root-Bernstein, Bioessays 2007; 29: 689–698) that homochirality and codon directionality emerged as a function of the origin of the genetic code itself. Further tests involving amplification methods are proposed.
Facts and Perspectives of Water Reservoirs in Central Asia: A Special Focus on Uzbekistan
Authors: Rakhmatullaev Shavkat , Huneau Frédéric , Le Coustumer Philippe , Motelica-Heino Mikael , Bakiev Masharif
Published: June 2010

The political transformation of the Central Asian region has induced the implosion of the interconnected physical hydraulic infrastructure and its institutional management system. Land-locked Central Asian countries, with their climatic conditions and transboundary water resources, have been striving to meet their food security, to increase agricultural production, to sustain energy sectors, and to protect the environment. The existing water reservoirs are strategic infrastructures for irrigation and hydropower generation. Upstream countries (Tajikistan and Kyrgyzstan) favor the reservoirs’ operation for energy supply, while downstream countries (Uzbekistan, Turkmenistan and Kazakhstan) push for irrigation use. This paper provides an overview of the current challenges and perspectives (technical, institutional, and legal regulations) and presents recommendations for the sustainable management of man-made water reservoirs in Uzbekistan.
Species boundaries and frequency of hybridization in the Dryopteris carthusiana (Dryopteridaceae) complex: A taxonomic puzzle resolved using genome size data
Authors: Ekrt Libor , Holubová Renata , Trávníček Pavel , Suda Jan
Published: June 2010

• Premise of the study: Genome duplication and interspecific hybridization are important evolutionary processes that significantly influence phenotypic variation, ecological behavior, and reproductive biology of land plants. These processes played a major role in the evolution of the Dryopteris carthusiana complex. This taxonomically intricate group composed of one diploid (D. expansa) and two allotetraploid (D. carthusiana and D. dilatata) species in Central Europe. Overall phenotypic similarity, great plasticity, and the incidence of interspecific hybrids have led to a continuous dispute concerning species circumscription and delimitation.

• Methods: We used flow cytometry and multivariate morphometrics to assess the level of phenotypic variation and the frequency of hybridization in a representative set covering all recognized species and hybrids.

• Key results: Flow cytometric measurements revealed unique genome sizes in all species and hybrids, allowing their easy and reliable identification for subsequent morphometric analyses. Different species often formed mixed populations, providing the opportunity for interspecific hybridization. Different frequencies of particular hybrid combinations depended primarily on evolutionary relationships, reproductive biology, and co‐occurrence of progenitors.

• Conclusions: Our study shows that genome size is a powerful marker for taxonomic decisions about the D. carthusiana complex and that genome size data may help to resolve taxonomic complexities in this important component of the temperate fern flora.
Upper Cretaceous woods from the Olmos Formation (late Campanian–early Maastrichtian), Coahuila, Mexico
Authors: Estrada‐Ruiz Emilio , Martínez‐Cabrera Hugo I. , Cevallos‐Ferriz Sergio R. S.
Published: June 2010

•Premise of the study: The Olmos Formation was part of a system of deltas that existed in the southern portion of the Western Interior of North America during the Campanian‐Maastrichtian. The paleofloristic composition from the northern portions of the Epicontinental Sea is relatively well known, but less intensive exploration in the south has precluded more detailed floristic comparison across the entire latitudinal span of the Sea. The Olmos Formation flora, with more than 100 different leaf morphotypes so far recognized and several wood types, has the most diverse Cretaceous fossil plant assemblage in Mexico and represents a valuable opportunity for comparative studies.

•Methods: The fossil woods here described were collected in the Coahuila State, Mexico. The samples were studied using standard thin section technique and identified by comparison with fossil and extant material.

•Key results: We described four new genera (Olmosoxylon, cf. Lauraceae;Coahuiloxylon, ?Anacardiaceae, ?Burseraceae;Muzquizoxylon, Cornaceae; andWheeleroxylon, Malvaceae s.l.) and three xylotypes of angiosperms.

•Conclusions: Some of the genera present in the Olmos Formation such asJavelinoxylonandMetcalfeoxylonhave been described from geologic units in the USA (San Juan Basin, New Mexico and Big Bend National Park, Texas), suggesting similarity in the taxonomic composition of the floras that inhabited southern portions of the western margin of the Campanian‐Maastrichtian Epicontinental Sea. Other species, however, have only been reported for the Olmos Formation, indicating some degree of local floristic differentiation among the assemblages that inhabited the southern portion of the Western Interior.
Ten microsatellite markers in endangered species Sauvagesia rhodoleuca (Ochnaceae)
Authors: Li Xiao‐Yi , Wang Zheng‐Feng , Zhu Peng , Ye Wan‐Hui , Huang Xiao‐Feng , Wu Lin‐Fang , Chai Sheng‐Feng , Cao Hong‐Lin
Published: June 2010

• Premise of the study: We developed microsatellite markers to investigate the level of genetic diversity within and among populations of the endemic shrub Sauvagesia rhodoleuca in China.

• Methods and Results: Ten polymorphic microsatellite loci were identified in five populations. The number of alleles per locus varied from 2 to 16. Observed and expected heterozygosities ranged from 0.000 to 1.000 and from 0.000 to 0.726, respectively.

• Conclusions: The results provide basic information on genetic diversity for future studies of population genetics in S. rhodoleuca.
A set of microsatellite markers for Arrabidaea chica (Bignoniaceae), a medicinal liana from the Neotropics
Authors: Figueira Glyn M. , Ramelo Pamela R. , Ogasawara Daniela C. , Montanari Ilio , Zucchi Maria I. , M.Cavallari Marcelo , Foglio Mary A.
Published: June 2010

• Premise of the study: Microsatellite markers were developed, optimized, and characterized for Arrabidaea chica (Humb. & Bonpl.) Verl. (Bignoniaceae), a Neotropical liana extensively used in folk medicine. The aim of this study was to develop molecular tools to investigate the genetic structure and diversity of natural populations and germplasm collections of this species.

• Methods and Results: Eight highly polymorphic microsatellite markers revealed a multibanded pattern, suggesting that the species is polyploid. The total number of bands per locus ranged from 9 to 17, revealing high levels of polymorphism.

• Conclusions: The high level of polymorphism detected with these markers indicates their utility in devising conservation strategies and rational exploitation of A. chica.
Synbiotic effects of lactitol and Lactobacillus acidophilus NCFM™ in a semi-continuous colon fermentation model
Authors: Mäkivuokko H. , Forssten S. , Saarinen M. , Ouwehand A. , Rautonen N.
Published: June 2010

The effects of Lactobacillus acidophilus NCFM™, lactitol, and the combination of lactitol and L. acidophilus NCFM™ were studied with a semi-continuous colon fermentation simulation; consisting of compartments mimicking, ascending, transverse, descending and sigmoid colon and their conditions with faecal inoculation. L. acidophilus NCFM™ was detected throughout the colon simulator. Lactitol was utilised early on by the microbes in the proximal part of the simulator. Lactitol increased the total numbers of microbes and bifidobacteria, and decreased clostridia cluster IV, while L. acidophilus NCFM™ alone decreased the numbers of clostridia cluster XIV. Combination treatment increased the numbers of bifidobacteria. Furthermore, concentrations of acetic acid, butyric acid and the sum of total short-chain fatty acids were increased by both lactitol-including treatments. The treatment with L. acidophilus NCFM™ alone increased the concentration of propionic acid and butyric acid. L. acidophilus NCFM™ tended to increase the total concentrations of biogenic amines, while lactitol suppressed production of biogenic amines also in the presence of L. acidophilus NCFM™. True synergistic effects are suggested in stimulation of the production of butyrate, an important microbial metabolite for colon health. In conclusion, lactitol as well as the combination of lactitol and L. acidophilus NCFM™ were found to exhibit complementary beneficial effects on the colon microbial composition and activity.
Greenroads: A Sustainability Performance Metric for Roadways
Authors: Muench Stephen T , Anderson Jeralee L , Söderlund Martina
Published: June 2010

Greenroads ( www.greenroads.us ) is a performance metric for sustainable practices associated with the design and construction of roads. It assigns points for approved sustainable choices/practices and can be used to assess roadway project sustainability measures based on total points. Such a metric can (1) provide a quantitative means of sustainability assessment, (2) allow informed sustainability decisions, (3) provide baseline sustainability standards, and (4) stimulate improvement and innovation in integrated roadway sustainability. This paper describes Greenroads version 1.0, which consists of 11 requirements and 37 voluntary practices that can be used as a project-level sustainability performance metric. Development efforts and a Washington State Department of Transportation (WSDOT) case study suggest (1) existing project data can serve as the data source for performance assessment, (2) some requirements and voluntary actions need refinement, (3) projects need to treat sustainability in a holistic manner to meet a reasonable sustainability performance standard, (4), the financial impact of Greenroads use must be studied, and (5) several pilot projects are needed. The Greenroads sustainability performance metric can be a viable means of project-level sustainability performance assessment and decision support.
Net Zero Energy Homes: An Evaluation of Two Homes in the Northeastern United States
Authors: Hoque Simi
Published: June 2010

This paper will discuss two Net Zero Energy homes in the United States. The aim is to discuss the differences and similarities in the construction type, energy use, active and renewable systems of the two homes. While each of the homes is designed to achieve net zero site energy use, the design and systems are very different. Furthermore, the measure that is used to qualify a home as net zero energy does not account for the full scope of work on each home. It is suggested that a new set of metrics be developed to allow for a more robust understanding of net zero energy buildings, one that integrates passive design strategies, occupant health and comfort, and durability. The objective is to facilitate a broader understanding of efficient and sustainable residential design. This understanding is critical to bringing Net Zero Energy Buildings to the public.
Interaction Per Se
Authors: Wiberg Mikael
Published: June 2010

Interaction is a core concept in the fields of Ubiquitous computing, Ambient systems design, and generally in the fields of HCI and Interaction Design. Despite this, a lack of knowledge about the fundamental character of interaction still exists. Researchers have explored interaction from the viewpoints of user-centered design and design of graphical user interfaces, where interaction stands for the link between technology and humans or denotes the use aspect. A framework is proposed for exploring interaction as a design space in itself between a human and the technology. It is proposed that this framework for interaction as a design space for Interaction Design, in which the very form of the in-between, the interaction, be explicitly targeted. It is an opportunity to go beyond user and usability studies to seek answers to fundamental questions concerning the form and character of interaction as implemented in today’s interactive systems. Moreover, this framework is an opportunity to expand and explain a new design space for Interaction Design. The proposed framework, anchored in two exemplifying cases, illustrates the character and the form of interaction as it situates itself in online, ubiquitous and everyday IT use.
Supporting Ontology-Based Semantic Annotation of Business Processes with Automated Suggestions
Authors: Di Francescomarino Chiara , Tonella Paolo
Published: June 2010

Annotation of Business Processes with semantic tags taken from a domain ontology is beneficial to several activities conducted on Business Processes, such as comprehension, documentation, analysis and evolution. On the other hand, the task of semantically annotating Business Processes is time-consuming and far from trivial. The authors support Business Process designers in the annotation of process elements by automatically suggesting candidate concepts. The annotation suggestions are computed on the basis of a similarity measure between the text information associated with process element labels and the ontology concepts. In turn, this requires support for the disambiguation of terms appearing in ontology concepts, which admit multiple linguistic senses, and for ontology extension, when the available concepts are insufficient.
Modeling and Simulation of a Six-Leg-Wheel Hybrid Mobile Robot Based on ADAMS
Authors: Li Yan Jie , Wu Zhen Wei
Published: June 2010

The dynamic modeling of a six-leg-wheel hybrid mobile robot was built using ADAMS software in this paper. Using the ADAMS model, the kinematic simulation, including the displacement, velocity and acceleration of each part of the robot, can be carried out and the dynamic simulation, including driving torque of joints, contact force and torque between the wheels with ground and the ability of obstacle negotiation, can also be achieved. The simulation examples were presented. The simulation analyses provide the theory basis for the design of the robot control system based on dynamics.
Numerical Simulation and Experiment of a New Drive Device of High-Temperature Magnetic Pump
Authors: Yuan Dan Qing , He You Quan , Li Jian Ping , Zhang He , Chang Chun Fang
Published: June 2010

To resolve the problem of degaussing of the magnetic pump, a new drive device is designed, consist of external magnetic rotor,isolation units and torque ring. Based on ANSYS12.0 analysis software, electromagnetic coupling method is firstly adopted on the simulation of this drive device. The comparison of simulation value and experimental data indicates that this method is feasible. For the purpose to provide evidence for more in-depth study of high temperature magnetic pump. Especialy,some key factors effecting on torque are considered, and this will provide references for further study of high-temperature magnetic pump.
Durability of Wood-PMMA Composite
Authors: Li Jian , Li Yong Feng , Meng Xin , Liu Yi Xing
Published: June 2010

Wood-PMMA composite was manufactured by impregnating methyl methacralyte (MMA) monomers into wood porous structure, followed by in-situ polymerization through catalyst-thermal treatment. The structure was simply analyzed by SEM and FTIR, and its durability was also examined. The results indicate that PMMA polymer generated in wood cellular structure, and interacted with wood cell walls, resulting in chemical combination between them. The durability involving dimensional stability, water repellency, decay resistance as well as acid resistance was whole improved over untreated wood. Such composite enhancing wood values can be used as structural furniture material and traffic material.
Preparation and Characterization of Nano-Calcium Titanate-Based Coated Silica Gel G and the Application in Adsorption of Heavy Metals
Authors: Zhang Dong , Liu Zhi Jiang
Published: June 2010

Nano-calcium titanate-based coated silica gel G (GCTO) was prepared by the citric acid sol–gel method and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and Fourier transform infrared spectrophotometry (FTIR). Its lead, cadmium and nickel ions adsorption properties from water were studied. Adsorption and elution were investigated under different conditions. The results showed that the nanometer calcium titanate was immobilized on the silica gel G firmly, becoming a new composite adsorbent. The lead, cadmium and nickel ions were quantitatively retained at pH 5-9; their adsorption capacities of GCTO were 114 mg•g－1, 11.2 mg•g－1 and 20.1 mg•g－1, respectively. The adsorbent can be regenerated completely by elution with 1 mol•L－1 HNO3. The adsorbent has a promising prospect in removal or enriching and separation of heavy metals in water.
Transverse Vibration Analysis of Euler-Bernoulli Beams Carrying Concentrated Masses with Rotatory Inertia at Both Ends
Authors: Zhang Yu , Xie Li Yang , Zhang Xiao Jin
Published: June 2010

Transverse vibration analysis is presented for Euler-Bernoulli beams carrying concentrated masses and taking into account their rotatory inertia at both ends. The dimensionless eigenfunctions for the problems are first obtained using the differential equations of motion and considering translational and rotatory springs at both ends. A numerical technique, the Newton–Raphson algorithm, is then used to solve vibration eigenfunctions of the beams. Finally, the influences of different non-dimensional parameters on frequencies are discussed.
Slitting Criterion for Various Slitting Roll Geometry in MSR Rolling Process
Authors: Stefanik Andrzej , Szota Piotr , Mróz Sebastian , Dyja Henryk
Published: June 2010

The main idea of multi slit rolling (MSR) technology is the capability of producing two, three, four and even five rods simultaneously from a single strip in a hot rolling process. Correct separation of the joined strips is one of the major problems in the MSR process. High tensile stresses (perpendicular to the rolling direction) are generated during movement of the band by the slitting rolls in the joining bridge. Critical value of the slitting criterion is mainly affected by geometry of the slitting rolls (angle, dimension and mass of the slitting rolls), temperature of the band and rolling speed. This paper presents results of numerical analysis of influence of the slitting roll angle on value of normalized Cockroft – Latham criterion during double slitting rolling process.
Objective Quantification of Neuromotor Symptoms in Parkinson's Disease: Implementation of a Portable, Computerized Measurement Tool
Authors: Papapetropoulos Spyridon , Katzen Heather L. , Scanlon Blake K. , Guevara Alexandra , Singer Carlos , Levin Bonnie E.
Published: June 2010

Quantification of neuromotor symptoms with device-based measures provides a useful supplement to clinical evaluation. Research using the CATSYS has established its utility as a computerized measurement system to quantify neuromotor function. The primary objective of this study is to provide technical guidance on the use of the CATSYS in Parkinson's disease (PD). Forty-four patients with idiopathic PD and 28 healthy controls were prospectively recruited and evaluated with CATSYS, a portable, Windows-based system consisting of a data logger and four different sensors (tremor pen, touch recording plate, reaction time handle, and force plate for balance recording) for quantification of neuromotor functions. CATSYS discriminated between PD and controls on measurements of rest/postural tremor, pronation/supination, finger tapping, simple reaction time, and postural sway intensity and velocity. CATSYS measurements using the proposed test battery were associated with relevant clinician-rated Unified Parkinson's disease rating scale (UPDRS) items assessing tremor and bradykinesia. More work is warranted to establish CATSYS as a diagnostic/monitoring instrument in movement disorders using the proposed technical approaches.
Die Skrif is aan ons toevertrou: Die implikasie van τὰ λόγια τοῦ θεοῦ in Romeine 3:2
Authors: Zuiddam Benno A.
Published: June 2010

In Paul’s Epistle to the Romans, the expression τὰ λόγια τοῦ θεοῦ refers to speech of God that was entrusted to the Jews as a people. This includes everything He spoke through Moses and the prophets. The apostle presents this as a matter of the greatest privilege to his readers, both for its authoritative contents and the personal involvement of the God of the Covenant it represents. Paul uses these ‘oracles’ or ‘very words of God’ as a collective reference (indicated by τὰ) to all divine speech that was entrusted to the Jews before the revelation of God’s righteousness in Christ, to which these λόγια τοῦ θεοῦ bore witness in advance. This article consequently argues that τὰ λόγια τοῦ θεοῦ refers to the Bible as phenomenon, the revealed Word of God that was entrusted to the Jewish people.
Trace Operators in Besov and Triebel–Lizorkin Spaces
Authors: Schneider Cornelia
Published: June 2010

We determine the trace of Besov spaces

\mathfrak B^s_{p,q}(\mathbb R^n)

and Triebel–Lizorkin spaces

\mathfrak F^s_{p,q}(\mathbb R_n)

– characterized via atomic decompositions – on hyperplanes

\mathbb R^m

,

n>m \in \mathbb N

, for parameters

0 < p, q \leq \infty

and

s > \frac{n−m}p

. The limiting case

s = \frac{n−m}p

is investigated as well. Our results remain valid considering the classical spaces

\bm B^s_{p,q}

,

\bm F^s_{p,q}

– deﬁned via differences. Finally, we include some density assertions, which imply that the trace does not exist when

s<\frac{n−m}p

.
Commutativity up to a Factor: More Results and the Unbounded Case
Authors: Mortad Mohammed Hichem
Published: June 2010

We give more results on the question of commutativity up to a factor for bounded operators and which has been recently of interest to a number of mathematicians. We also give some generalizations to unbounded operators.
Non-Local Hamilton-Jacobi Equations Arising in Dislocation Dynamics
Authors: Ishii Hitoshi , Matsumura Yutaka
Published: June 2010

We investigate a class of non-local Hamilton–Jacobi equations arising in dislocation dynamics. The class of Hamilton–Jacobi equations treated here is a variation of those studied by N. Forcadel, C. Imbert and R. Monneau in [Discrete Contin. Dyn. Syst. 23 (2009)(3), 785 – 826], and the new feature lies in the singularity at the origin of the kernel functions which describe non-local eﬀects. For the class of Hamilton–Jacobi equations, we establish some stability properties of (viscosity) solutions, comparison theorems between subsolutions and supersolutions and existence theorems of solutions.
La didactique a-t-elle raison de s'intéresser à l'histoire des sciences?
Authors: Raichvarg Daniel
Published: June 2010

Should didactics be interested in the history of sciences ?

The relationship between historical and individual construction of knowledge is inevitably a field of investigation for didactics. A particular conception, however, "le récapitulationnisme", born in the 19th century, seems to constitute a screen which prevents heuristic approach to the question. We analyse here the recapitulationist model as a Science historian, pointing out the conditions of its emergence and the modifications of its intension and extension ; we try in this way to overcome this obstacle. While outlining the epistemological history of this concept, we signal the elements which, from Baldwin to Bachelard, including Haeckel, Freud and Piaget, may help to ground didactical investigations.
Reworking of amino acid in marine sediments: Stable carbon isotopic composition of amino acids in sediments along the Washington coast
Authors: Keil Richard G. , Fogel Marilyn L.
Published: June 2010

The stable carbon isotopic composition of nine individual amino acids were investigated in phytoplankton and zooplankton, estuarine plankton, terrigenous material, marine fecal material, and clay mineral isolates collected along the Washington coast. The clay fraction was isolated from suspended sediments of the Columbia River (the mineral source) and three shelf and slope stations (mineral deposition sites). In the sediments, terrigenous amino acids were replaced by those of marine origin, and microbial reworking of the amino acids further influenced their d13C compositions. Based on changes in isotopic composition, individual amino acids could be roughly divided into three groups. (1) Leucine and proline had isotopic shifts similar to bulk organic matter. On average, 80% of these river‐delivered amino acids were replaced by marine‐derived material. (2) Alanine, isoleucine, glutamic acid, aspartic acid, and phenylalanine had intermediate isotopic shifts. These isotopic compositions are consistent with both the expected isotopic fractionation associated with microbial resynthesis of amino acids using marine substrates and/or preservation of ~50% of the terrigenous component in the marine environment. (3) Glycine and valine exhibited isotopic values outside the range of our sampled end members. Their unusual isotopic compositions are attributed to reworking of their isotopic signal during diagenesis. Microbial resynthesis of amino acids during growth on mixed substrates may account for nearly all the observed variation in amino acid isotopic composition. Similarity between the amino acid isotopic composition of the fecal material and that of the clay isolates suggests that alterations of the isotopic composition of the amino acids might occur while the amino acids are in distinct organic‐rich debris, prior to long‐term association with the sediment.
Chemoautotrophy in the redox transition zone of the Cariaco Basin: A significant midwater source of organic carbon production
Authors: Taylor Gordon T. , Iabichella Maria , Ho Tung-Yuan , Scranton Mary I. , Thunell Robert C. , Muller-Karger Frank , Varela Ramon
Published: June 2010

During the CARIACO time series program, microbial standing stocks, bacterial production, and acetate turnover were consistently elevated in the redox transition zone (RTZ) of the Cariaco Basin, the depth interval (~240–450 m) of steepest gradient in oxidation‐reduction potential. Anomalously high fluxes of particulate carbon were captured in sediment traps below this zone (455 m) in 16 of 71 observations. Here we present new evidence that bacterial chemoautotrophy, fueled by reduced sulfur species, supports an active secondary microbial food web in the RTZ and is potentially a large midwater source of labile, chemically unique, sedimenting biogenic debris to the basin's interior. Dissolved inorganic carbon assimilation (27–159 mmol C m−2 d−1) in this zone was equivalent to 10%–333% of contemporaneous primary production, depending on the season. However, vertical diffusion rates to the RTZ of electron donors and electron acceptors were inadequate to support this production. Therefore, significant lateral intrusions of oxic waters, mixing processes, or intensive cycling of C, S, N, Mn, and Fe across the RTZ are necessary to balance electron equivalents. Chemoautotrophic production appears to be decoupled temporally from short‐term surface processes, such as seasonal upwelling and blooms, and potentially is more responsive to long‐term changes in surface productivity and deep‐water ventilation on interannual to decadal timescales. Findings suggest that midwater production of organic carbon may contribute a unique signature to the basin's sediment record, thereby altering its paleoclimatological interpretation.
Species and epilimnion/hypolimnion‐related differences in size at larval settlement and metamorphosis in Dreissena (Bivalvia)
Authors: Martel André L. , Baldwin Brad S. , Dermott Ronald M. , Lutz Richard A.
Published: June 2010

Recently settled postlarval quagga mussels (Dreissena bugensis) and zebra mussels (D. polymorpha) were examined using optic microscopy to determine planktonic shell growth and size at settlement and metamorphosis from two habitats in Eastern Lake Erie: nearshore epilimnion and offshore hypolimnion. Postlarvae (shell length ~400‐2000 µm) were collected from various substrates between 1992 and 1995. Planktonic shell growth and size at settlement and metamorphosis were determined by measuring height of the prodissoconch I (PI) and prodissoconch II (PII) on right valves. Mean PI height was 79.07 (SD = 4.64) and 79.62 µm (SD = 4.28) for the quagga and zebra mussel, respectively, and did not differ between species or across habitats. There was, however, a distinct between‐species difference in size at settlement and metamorphosis (PII size), with larvae of the quagga mussel settling at significantly larger sizes than those of the zebra mussel (nearshore/epilimnion data: quagga PII means, 256‐284 µm; zebra PII means, 236‐249 µm). In addition, quagga mussel larvae settled at a greater size in the offshore hypolimnion habitat (PII mean = 313.64 µm, SD = 24.69, n = 320) compared to nearshore epilimnion habitat (mean = 261.89 µm, SD = 19.41, n = 207). The additional 28% of larval shell (PII) secreted by offshore hypolimnion quagga mussels may be linked to several factors, including a prolonged planktonic period. This study is the first to document the relationship between offshore distance and size at settlement in a bivalve.
Modeling detailed sedimentary 210Pb and fallout 239,240Pu profiles to allow episodic events: An application in Chesapeake Bay
Authors: Nie Yonghong , Suayah Ismail B. , Benninger Larry K. , Alperin Marc J.
Published: June 2010

Dependable sediment chronologies are essential to the interpretation of the sedimentary record of past environmental change. In the present article, we use high‐resolution chemical and radiochemical data as the basis for a numerical simulation of sediment accumulation, bioturbation, and episodic deposition or erosion in a dynamic estuary. We simulate episodic events by employing a time dependent sedimentation rate that we solve by finding a set of model parameters that describes depth profiles of both excess 210Pb and fallout 239,240Pu. We apply the model to depth distributions of these tracer nuclides in cores from upper‐, mid‐ and lower‐Bay sites in Chesapeake Bay. At the upper‐Bay site, combining chemical and radiochemical data permits us to recognize and to quantify the sediment deposition due to tropical storm Agnes (1972). At the lower‐Bay site, we demonstrate nonsteady sedimentation and propose plausible scenarios to account for it. Given adequate data, our model can provide information that is not available from steady‐state models.
Seasonal dynamics of coastal ecosystems and export production at high latitudes: A modeling study
Authors: Tian Ru Cheng , Vézina Alain F. , Starr Michel , Saucier François
Published: June 2010

Export of organic matter from the surface to deeper waters often shows much smaller seasonal variations than primary production or nitrate‐based new production in mid‐ to high‐latitude marine systems. The mechanisms underlying this pattern remain poorly understood, but seasonal shifts in food web structure and dynamics have been implicated. We report here on an ecosystem modeling analysis of a high‐resolution (biweekly) time series of biomass, production, and export flux (sediment trap) measurements conducted in 1991 in Bonne Bay (Newfoundland). This time series shows the classical pattern of a spring bloom followed by a summer low biomass period, yet export is bimodal, with maxima during spring and late summer. The ecosystem model was forced by diagnostic vertical mixing calculations based on temperature and salinity records taken every 3 d and hourly wind data. The physical analysis indicated that the nitrate flux into the euphotic zone during summer was equivalent to that during the spring and fall seasons and accounted for half of the summer export. Statistical adjustments of the parameters of the ecosystem model indicated that strong production of dissolved organic carbon during the spring bloom, high temperature dependence of microbial activity, and physico‐chemical particle aggregation played key roles in explaining the remainder of the summer export. Seasonal changes in trophic pathways between spring and summer, such as a shift from a herbivorous to a microbial food web, played a comparatively smaller role. Our modeling analysis suggests that physical mixing processes and physico‐chemical aggregation processes are at least as important as shifts in food web trophic pathways in explaining the postbloom export flux in mid‐ to high‐latitude marine systems.
Dynamics of phytoplankton succession coupled to species diversity as a system‐level tool for study of Microcystis population dynamics in eutrophic lakes
Authors: Roelke Daniel , Buyukates Yesim
Published: June 2010

Many of the processes that influence initiation and development of harmful algal blooms (HABs) in lake ecosystems also affect the nature of phytoplankton population overturnߞhere referred to as the dynamics of succession ߞand species diversity. Consequently, the dynamics of succession and species diversity might reflect the lake's resistance to HABs. We explored this idea by developing a potential systemߚlevel tool based on the coupling of these two characters, where the dynamics of succession were quantified using a first derivative index, and tested it in a single lake plagued by recurrent blooms of Microcystis aeruginosa. Our analysis showed that if nonbloom periods were characteristic of either low succession dynamics or low species diversity, M. aeruginosa blooms followed. However, when succession dynamics and species diversity were both high for an extended period, a M. aeruginosa bloom did not follow. Should this relationship hold true in other lakes and when blooms are not as severe, a coupling of succession dynamics to species diversity might prove useful as a tool to evaluate M. aeruginosa population dynamics at the system level. Data at the species level were needed to elucidate this inverse relationship between M. aeruginosa bloom initiation and the dynamics of succession coupled to species diversity. When species data were grouped into coarse taxonomic categories (i.e., groups discernable using in vivo absorption spectra) the relationship was not detectable.
Fundamental changes in light scattering associated with infection of marine bacteria by bacteriophage
Authors: Balch William M. , Vaughn James M. Jr , Novotny James F. , Drapeau David T. , Goes Joaquim I. , Booth Emily , Lapierre Janeen M. , Vining Cathy L. , Ashe Amanda , Vaughn James M. Jr
Published: June 2010

Bacteria and phytoplankton are key determinants of the ocean's inherent optical properties. Despite their high abundance, marine viruses have generally been thought to play a minor role in ocean optics because of their small scattering cross‐sections. Nevertheless, the role of specific viral infection on the optical properties of bacteria and phytoplankton has remained unknown (i.e., as viruses disrupt micron‐sized host cells to produce submicron cell debris). Here, we used laboratory and mesocosm cultures of marine bacteria for virus infection experiments in which growth conditions and host‐virus specificity were controlled. We report that the chief optical impact of viruses is associated with infection and lysis of their hosts. We quantitatively describe, for the first time, two optical changes associated with infection and lysis of marine bacteria by bacteriophage: (1) rapid, strong shifts in the magnitude and shape of the optical volume scattering function and (2) rapid production of colored dissolved organic material. Qualitatively, these changes result in nearly complete clearing of turbid host bacterial suspensions. Although some optical differences would be expected between infection of bacteria in laboratory cultures versus field populations (mainly because of differences in cell size), these results are applicable to the field, especially for dense host suspensions such as in blooms. Even in nonbloom situations, as long as the host bacteria contribute a significant amount of the total particle backscattering, we expect that virus‐induced backscattering changes would be detectable by use of satellite or aircraft remote‐sensing techniques.
Seasonal and interannual variability in sources of nitrogen supporting export in the oligotrophic subtropical North Pacific Ocean
Authors: Dore John E. , Brum Jennifer R. , Tupas Luis M. , Karl David M.
Published: June 2010

Over timescales of months to years, the export of organic nitrogen from the oceanic euphotic zone (principally as sinking particulate nitrogen, PN) is believed to balance the input of exogenous combined inorganic nitrogen (i.e., export production balances new production). In the oligotrophic North Pacific subtropical gyre, there are two significant sources of new nitrogen: the upward flux of nitrate from deep water and the biological fixation of dissolved N2 in near‐surface waters. Because these sources have distinct stable isotopic signatures, we were able to use the total PN and Δ15N measurements of sinking particles and an isotopic mass balance model to deconvolute the relative and absolute contributions of the nitrate flux and nitrogen fixation to the gravitational export of PN. The sinking flux of PN and its isotopic composition both varied widely between 1989 and 2001. Seasonally, N2 fixation correlated inversely with mixed‐layer depth, reaching a maximum in June‐August, whereas nitrate‐supported export correlated inversely with sea surface temperature, reaching a maximum in February‐March. These patterns were consistent with summertime increases in diazotroph biomass and water column N2 fixation rates, as indicated by phycoerythrin pigment concentrations and 15N2 tracer studies. Annually, the relative contribution of N2 fixation to N export varied from 36 to 69% (mean = 48%) and showed a significant increasing trend over the period of observation. Although total PN export correlated with the Southern Oscillation Index, the nitrate‐ and nitrogen fixation‐based components appeared to respond to climate forcing in distinct ways, complicating our interpretation of the mechanisms of climate‐induced changes in particle export.
Extreme water velocities: Topographical amplification of wave‐induced flow in the surf zone of rocky shores
Authors: Denny M. W. , Miller L. P. , Stokes M. D. , Hunt L. J. H. , Helmuth B. S. T.
Published: June 2010

Water velocities as high as 25 m s−1 have been recorded in the surf zone of wave‐swept rocky shores—velocities more than twice the phase speed of the breaking waves with which they are associated. How can water travel twice as fast as the waveform that initially induces its velocity? We explore the possibility that the interaction of a wave with the local topography of the shore can greatly amplify the water velocities imposed on intertidal plants and animals. Experiments in a laboratory wave tank show that interactions between bores refracted by a prowlike beach can produce jets in which the velocity is nearly twice the bore's phase speed. This velocity can be further amplified by a factor of 1.3–1.6 if the jet strikes a vertical wall. This type of topographically induced amplification of water velocity could result in substantial spatial variation in wave‐induced hydrodynamic forces and might thereby help to explain the patchwork nature of disturbance that is characteristic of intertidal communities.
Source identification and budget analysis on elevated levels of formaldehyde within ship plumes: a photochemical/dynamic model analysis
Authors: Song C. H. , Kim H. S. , von Glasow R. , Brimblecombe P. , Kim J. , Park R. J. , Woo J. H.
Published: June 2010

Abstract. Elevated levels of formaldehyde (HCHO) along the ship corridors have been observed by satellite sensors, such as ESA/ERS-2 GOME (Global Ozone Monitoring Experiment), and were also predicted by global 3-D chemistry-transport models. In this study, three likely sources of the elevated HCHO levels were investigated to identify the detailed sources and examine the contributions of the sources (budget) of the elevated levels of HCHO in the ship corridors using a newly-developed ship-plume photochemical/dynamic model: (1) primary HCHO emission from ships; (2) secondary HCHO production via the atmospheric oxidation of Non-methane volatile organic compounds (NMVOCs) emitted from ships; and (3) atmospheric oxidation of CH4 within the ship plumes. From multiple ship-plume model simulations, CH4 oxidation by elevated levels of in-plume OH radicals was found to be the main factor responsible for the elevated levels of HCHO in the ship corridors. More than ~91% of the HCHO for the base ship plume case (ITCT 2K2 ship-plume case) is produced by this atmospheric chemical process, except in the areas close to the ship stacks where the main source of the elevated HCHO levels would be primary HCHO from the ships (due to the deactivation of CH4 oxidation from the depletion of in-plume OH radicals). Because of active CH4 oxidation (chemical destruction of CH4) by OH radicals, the instantaneous chemical lifetime of CH4 (τ CH4) decreased to ~0.45 yr inside the ship plume, which is in contrast to τ CH4 of ~1.1 yr in the background (up to ~41% decrease). A variety of likely ship-plume situations at three locations at different latitudes within the global ship corridors was also studied to determine the extent of the enhancements in the HCHOlevels in the marine boundary layer (MBL) influenced by ship emissions. It was found that the ship-plume HCHO levels could be 20.5–434.9 pptv higher than the background HCHO levels depending on the latitudinal locations of the ship plumes (i.e., intensity of solar radiation and temperature), MBL stability and NOx emission rates. On the other hand, NMVOC emissions from ships were not found to be a primary source of photochemical HCHOproduction inside ship plumes due to their rapid and individual dilution. However, the diluted NMVOCs would contribute to the HCHO productions in the background air. The greater impact of ship-plume photochemistry on the atmospheric MBL oxidation cycles, global climate, and marine eco-system in the global ship corridors are also discussed based on the results in this study.