bluuebunny/crossref_metadata_2025 huggingface dataset:
Challenges in Implementing New Technology for Beach Water Quality Monitoring: Lessons From a California Demonstration Project
Authors: Griffith John F. , Weisberg Stephen B.
Published: October 2011

AbstractBeach water quality is currently monitored using culture methods that require 24 h, but quantitative polymerase chain reaction (qPCR) can be performed in 2 h. Efforts to date have focused on technology development, with less attention to practical challenges of method
implementation. Here, we present a demonstration project in which qPCR was used to make health protection decisions at nine beaches. Project goals were to assess success in technology transfer, consistency of results between culture-based and qPCR methods, and success in implementing health
protection decisions the same day the samples were collected. Technology transfer went smoothly, as laboratories routinely produced amplification efficiencies >90%, a high degree of repeatability between replicates, and results comparable to that of an experienced reference laboratory.
qPCR slightly overestimated levels of Enterococcus compared to culture-based methods, and some samples were rejected due to PCR inhibition. However, a stakeholder task force did not consider these an impediment to method adoption, because they were outweighed by the value of providing
same-day results. Providing warnings by noon was challenging, but was achieved by limiting the number of sites and using electronic means for communicating warnings. The task force concluded that capital and training costs were a smaller impediment to method adoption than the expectation for
more monitoring, as there is no benefit to rapidity if a result is extrapolated across a week. Cost and temporal logistics are likely to limit initial use of rapid methods, primarily at beaches that are heavily used and/or have the most variable water quality.
Chemical Spill Characteristics in the San Diego Bay
Authors: Chu Peter C. , Kyriakidis Kleanthis
Published: October 2011

AbstractDispersion of ocean pollutants in estuarine environments and bays (such as San Diego Bay) depends on the location of the source of the pollutants relative to the mouth and the tidal excursion, which is the net horizontal distance over which a pollutant particle moves
during one tidal cycle of flood and ebb. Pollutant dispersion was investigated using a coupled hydrodynamic and chemical discharge model in this study. The results show the existence of two distinct (northern and southern) spill patterns of pollutant dispersion. The northern spill pattern
is characterized by fast reduction of the pollutant concentration in the water column, rapid dispersion of pollutants to the San Diego port and to outside of the San Diego Bay, and slow dispersion of pollutants to the southern bay. The southern spill pattern is characterized by slow reduction
of the pollutant concentration in the water column, slow dispersion, and confinement of pollutants in the southern San Diego Bay. The results may be useful for ocean pollution control and management.
Development of a New Spilled Oil Tracking Autonomous Buoy
Authors: Senga Hidetaka , Kato Naomi , Suzuki Hiroyoshi , Yoshie Muneo , Fujita Isamu , Tanaka Toshinari , Matsuzaki Yoshitaka
Published: October 2011

AbstractOil spills cause tremendous damage to the ocean environment, which the unfettered drifting of spilled oil exacerbates. If the exact location of drifting oil could be identified in real time beginning when the oil spill first occured, then drifting oil could be recovered
at sea before washing ashore. In addition, if meteorological and oceanographic data around the drifting oil could be obtained, the accuracy of an oil drifting simulation would be enhanced by data assimilation, and oil recovery machines could be adequately deployed along coasts where spilled
oil washes ashore based on the simulation results. We developed a spilled oil tracking autonomous buoy I (SOTAB-I), which tracks spilled oil autonomously and transmits useful data in real time. Sea trials using the SOTAB-I showed that it has efficient tracking procedures. The trials also showed
that the drift of spilled oil is strongly affected by wind.In order to take into account the wind effect, a new SOTAB, which has a sail with a changeable size and direction, was developed, and sea trials were carried out. The experimental results revealed that the drifting velocity of
the SOTAB-II was 3.1%-3.8% of the wind velocity along the wind direction. When the sail was completely furled, the drifting direction of the new SOTAB-II was different from that of the imaginary drifting oil. However, the drifting direction was decreased when the sail was completely unfurled.
These results show the efficiency of the sail attached to the SOTAB-II.
Environmental Security in Arctic Ice-Covered Seas: From Strategy to Tactics of Hazard Identification and Emergency Response
Authors: Eicken Hajo , Jones Joshua , Meyer Franz , Mahoney Andy , Druckenmiller Matthew L. , Rohith MV , Kambhamettu Chandra
Published: October 2011

AbstractEnvironmental change and increasing industrial activity in the maritime Arctic require strategies to adapt to change and ensure safe operations. This problem has been defined at the broader strategic level. We evaluate key aspects of environmental security in ice-covered
waters, focusing on tactical and operational information needs, which have received less attention. Monitoring of environmental hazards and effective emergency response in sea ice environments require high-resolution data of ice hazard distributions (e.g., multiyear ice, landfast ice breakout,
and ice push events), ice movement and deformation, as well as ice characteristics and dynamics relevant to emergency response. We have developed a prototype coastal observing system at Barrow, Alaska, that addresses such information needs. Imagery obtained from a marine X-band radar with
a digital controller is combined with data from on-ice sensors (ice thickness, ice and water temperature, sea level) and assessments of potentially hazardous ice conditions by local experts. Digital imagery and data are processed and disseminated in near-real time. Using a combination of image
processing approaches (optical flow, Lucas-Kanade tracker), ice velocity fields, floe trajectories, and boundaries of stationary ice are derived automatically. Early onset of hazardous events is detected through Hidden Markov Modeling, providing potential decision support in operational settings.
We evaluate the utility of the system and strategies towards integration with broader emergency response efforts.
Passive Acoustic Array Harbor Security Applications
Authors: Gebbie John , Siderius Martin , Allen John S.
Published: October 2011

AbstractHarbor security and protection of maritime assets are issues of increasing concern. Outstanding research questions exist in terms of the optimal protection methodology needed for the wide variety of surface and submerged threats and diverse geographical locations.
Economic costs and environmental concerns are also significant overriding issues. Acoustic methods have the advantage of being amenable to tracking and detecting targets both above and below the ocean surface. Moreover, passive acoustic methods are nonintrusive and capable of covering extensive
ranges. Acoustic arrays offer significant advantages in terms of gain and signal processing capabilities over discrete, single hydrophones. We investigate the use of horizontal and vertical arrays for the detection and tracking of a remote environment monitoring system (REMUS) autonomous underwater
vehicle as well as open-circuit divers in a noisy, shallow water environment. Using conventional beamforming techniques, we obtain positive preliminary results for detection and tracking, which highlight the overall merits of an acoustic array implementation.
A High-Latitude Modular Autonomous Power, Control, and Communication System for Application to High-Frequency Surface Current Mapping Radars
Authors: Statscewich Hank , Weingartner Tom , Danielsen Seth , Grunau Bruno , Egan Greg , Timm Jeb
Published: October 2011

AbstractHigh-frequency, shore-based radars (HFR) collect hourly, real-time surface current data over broad areas of the coastal ocean and yield insights on time-varying circulation, predict oil spill trajectories, evaluate circulation models, and, in case of a spill, provide
responders with real-time data on spill evolution. HFR requires 7.5 kWh/day of power, but the lack of power availability inhibits HFR use in Alaska. We developed a modular, autonomous remote power module (RPM) for Arctic environments. The RPM design facilitates setup and transport to remote
sites using small vehicles, and it contains subsystems for power generation, satellite communications, and power performance monitoring. The subsystems are powered by a battery bank (with a 5-day power reserve) charged primarily by wind and solar and secondarily by a biodiesel generator. The
RPM is a stand-alone device for long-term deployments. It minimizes permit issues associated with diesel generators and logistics costs associated with refueling and maintenance. Performance data from a prototype RPM setup in Barrow, Alaska, in fall 2010 is provided. The system is designed
for high latitudes but can be modified for remote coasts elsewhere.
A Hybrid Class Underwater Vehicle: Bioinspired Propulsion, Embedded System, and Acoustic Communication and Localization System
Authors: Krieg Michael , Klein Peter , Hodgkinson Robert , Mohseni Kamran
Published: October 2011

AbstractInspired by the natural locomotion of jellyfish and squid, a series of compact thrusters series is developed for propulsion and maneuvering of underwater vehicles. These thrusters successively ingest and expel jets of water in a controlled manner at high frequencies
to generate propulsive forces. The parameters controlling the performance of the thrusters are reviewed and investigated to achieve higher thrust levels. The thrusters are compact and can be placed completely inside a vehicle hull providing the desired maneuvering capability without sacrificing
a sleek hydrodynamic shape for efficient cruising. The system design of a prototype hybrid vehicle, called CephaloBot, utilizing these thrusters, is also presented. A compact and custom-developed embedded system is also designed for the CephaloBot. Key features of the system include a base
set of navigational sensors, an acoustic system for localization and underwater communication, Xbee RF transceiver for communication above water, and a LabVIEW programmed processing board.
Shark Skin Separation Control Mechanisms
Authors: Lang Amy , Motta Philip , Habegger Maria Laura , Hueter Robert , Afroz Farhana
Published: October 2011

AbstractDrag reduction by marine organisms has undergone millions of years of natural selection, and from these organisms biomimetic studies can derive new technologies. The shortfin mako (Isurus oxyrinchus), considered to be one of the fastest and most agile marine
predators, is known to have highly flexible scales on certain locations of its body. This scale flexibility is theorized to provide a passive, flow-actuated mechanism for controlling flow separation and thereby decreasing drag. Recent biological observations have found that the shortfin mako
has highly flexible scales, bristling to angles in excess of 50°, particularly on the sides of the body downstream of the gills. High “contragility,” which is explicitly defined here as the ability to change or move in a new or opposing direction while already in a turn, would
occur if form drag were minimized. This would thus indicate the potential control of flow separation on body regions aft of the point of maximum girth or in regions of adverse pressure gradient. Thus results are consistent with the hypothesis that scale bristling controls flow separation.
This scale flexibility appears to be a result of a reduction in the relative size of the base of the scales as well as a reorganization of the base shape as evidenced by histological examination of the skin and scales. Probable mechanisms leading to separation control are discussed.
A Twistable Ionic Polymer-Metal Composite Artificial Muscle for Marine Applications
Authors: Kim Kwang J. , Pugal David , Leang Kam K.
Published: October 2011

AbstractIonic polymer-metal composite (IPMC) artificial muscles (AMs), due to their low driving voltage (<5 V), large strain, soft and flexible structure, and ability to operate in an aqueous environment, are suited for creating artificial fish-like propulsors that can
mimic the undulatory, flapping, and complex motions of fish fins. Herein, a newly developed IPMC AM fin with patterned electrodes is introduced for realizing multiple degrees-of-freedom motion, such as bending and twisting. Also, by carefully creating isolated patterns of electrodes on the
surface of the polymer-metal composite, sections of the composite can function as an actuator, while other areas can be used for sensing fin deformation and responses to external stimulation. The manufacturing, modeling, and characterization of a twistable AM fin are discussed. The sectored
electrode pattern on the AM fin is created using two techniques: masking and surface machining. Using first principles, detailed models are developed to describe the electromechanical transduction for the IPMC AM fin. These models can be used to guide the development of more complex AM fin
geometries and electrode patterns. The bending and twisting performance of a prototype twistable AM fin is evaluated and compared to the models. Experimental results demonstrate good twisting response for a prototype fin. Technical design challenges and performance limitations are also discussed.
T Cell-Signaling Network Analysis Reveals Distinct Differences between CD28 and CD2 Costimulation Responses in Various Subsets and in the MAPK Pathway between Resting and Activated Regulatory T Cells
Authors: Kalland Maria Elisabeth , Oberprieler Nikolaus Günter , Vang Torkel , Taskén Kjetil , Torgersen Knut Martin
Published: October 2011

To uncover signaling system differences between T cell stimuli and T cell subsets, phosphorylation status of 18 signaling proteins at six different time points following TCR triggering and CD28/CD2 costimulation was examined in human T cell subsets by phospho-epitope–specific flow cytometry of fluorescent cell barcoded samples, thereby providing a high-resolution signaling map. Compared with effector/memory T cells, naive T cells displayed stronger activation of proximal signaling molecules after TCR triggering alone. Conversely, distal phosphorylation events, like pErk and pS6-ribosomal protein, were stronger in effector/memory subsets. CD28 costimulation specifically induced signaling necessary for proper NF-κB activation, whereas CD2 signaled more strongly to S6-ribosomal protein. Analysis of resting regulatory T cells (rTregs; CD4+CD45RA+FOXP3+) and activated regulatory T cells (actTregs; CD4+CD45RA−FOXP3++) revealed that, although rTregs had low basal, but inducible, Erk activity, actTregs displayed high basal Erk phosphorylation and little or no Akt activation. Interestingly, the use of Mek inhibitors to block Erk activation inhibited activation-dependent FOXP3 upregulation in rTregs, their transition to actTregs, and the resulting increase in suppressive capacity. In summary, our systems approach unraveled distinct differences in signaling elicited by CD28 and CD2 costimulation and between rTregs and actTregs. Blocking rTreg transition to highly suppressive actTregs by Mek inhibitors might have future therapeutic applications.
A Novel ZnO-Methylene Blue Nanocomposite Matrix for Biosensing Application
Authors: Saha Shibu , Arya S. K. , Singh S. P. , Gupta Vinay
Published: October 2011

A novel hybrid matrix of zinc oxide-methylene blue (ZnO-MB) has been successfully developed for biosensing application. The introduction of methylene blue into the ZnO thin film leads to reduction in the charge transfer resistance and suggests an increase in the electron transfer capacity of the composite. Glucose oxidase (GOx) was chosen as the model enzyme and effectively immobilized on the surface of hybrid ZnO-MB nanocomposite matrix. Electrochemical measurements were employed to study biosensing response of the GOx/ZnO-MB/ITO bioelectrode as a function of glucose concentration. The low oxidation potential (−0.23 V) of the hybrid bioelectrode, in a mediatorless electrolyte, makes it resistant against interference from other bio-molecules. The low value of Michaelis-Menten constant (2.65 mM) indicates that immobilized GOx retains its enzymatic activity significantly on the surface of nanocomposite hybrid matrix that results in an enhanced affinity towards its substrate (glucose). The ZnO-MB nanocomposite hybrid matrix, exhibiting enhanced sensing response (0.2 μAmM−1cm−2) with long shelf-life (>10 weeks), has potential for the realization of an integrated biosensing device.
Unusual Case of a Graphite Foreign Body in the Anterior Chamber
Authors: Amritanand Anika , John Sheeja S. , Philip Swetha S. , John Deepa , David Sarada
Published: October 2011

Retained intraocular graphite foreign bodies are uncommon. Although they are generally inert, they have been reported to cause severe inflammatory reaction and progressive damage to intraocular structures. We report a case of a six-year-old girl with a retained intraocular graphite pencil lead foreign body in the anterior chamber of the eye and discuss the various considerations in the management of such cases.
Sleep Insufficiency, Sleep Health Problems and Performance in High School Students
Authors: Ming Xue , Koransky Rebecca , Kang Victor , Buchman Sarah , Sarris Christina E. , Wagner George C.
Published: October 2011

A survey on sleep schedule, sleep health, school performance and school start times was conducted in 1,941 adolescents. A high level of early and circadian-disadvantaged sleep/wake schedules during weekdays was observed. Shorter sleep duration on weekdays was reported, especially in upper classmen. Complaints of inadequate sleep and sleepiness during weekdays, alarm clock use, and napping were prevalent. Night awakening and prolonged sleep onset were common and associated with poor school performance. Students with a sleep length of less than 7 hours on both weekdays and weekends exhibited poorer performance, while those who made up this sleep loss on weekends did not. The total number of poor sleep factors in an individual also correlated with poor school performance. Earlier school start times were associated with a perception of poor sleep quality, shorter sleep duration and more sleep health problems. We conclude that sleep inadequacies and sleep health problems were prevalent in this population, especially in those who started school earlier in the morning, and that these poor sleep factors were associated with school performance.
Management Options in Advanced Prostate Cancer: What is the Role for Sipuleucel-T?
Authors: Bitting Rhonda L. , Armstrong Andrew J. , George Daniel J.
Published: October 2011

Most prostate cancer-related deaths occur in patients with castration-resistant prostate cancer (CRPC). Until recently, only therapy with docetaxel and prednisone has been shown to prolong survival in men with metastatic CRPC. With the United States Food and Drug Administration (US FDA) approvals of sipuleucel-T, cabazitaxel, and abiraterone acetate, all based on improvement in overall survival, the landscape for management of men with metastatic CRPC has dramatically changed. In this review we will discuss the pivotal clinical trial data leading to these approvals, with particular focus on the unique indication for sipuleucel-T and the implications for optimal management and sequencing of treatment in this patient population.
Interchange vs. Interoperability
Authors: Bauman Syd
Published: October 2011

This paper explores some of the ramifications of the inherent tension between the desire to analyze our own data and to share it with others — between our desire to be expressive and our desire to be conformant — particularly with respect to interchangeability vs. interoperability, positing that focusing on interoperability is to focus on sharing at the expense of analysis.
Challenges and Potential of Local Loading of XML Ebooks
Authors: David Ravit H. , Sahebi Shahin Ezzat , Kawula Bartek , Jayasinghe Dileshni
Published: October 2011

This paper is a summary of the experience of local loading of XML Ebooks on the Scholars Portal Ebook platform. It discusses the problems and potential of local loading that emerged from a pilot loading of over 500 titles; the first stage of this pilot was completed in February 2011. More specifically, the paper will review the difficulties encountered during the various stages of the loading, starting from loading files on our MarkLogic server, then the presentation of content via XSLT and ending with transforming the table of contents to achieve functionalities, such as lone-chapter downloading. We will also touch upon our web reader and the features developed to enhance the reading experience of XML Ebooks.

Our conclusion is that with the gradual increase in publishers’ switching from PDF to XML format, the need to have a standard for XML Ebooks increases, as well; local loading of XML Ebooks in their current format suggests that much programming work will be called for in order to arrive at the best presentation of the content.

Finally, we will suggest that once a satisfying web-based presentation of XML Ebooks is achieved, there will still be an urgent need to develop good readers in order to provide a friendly reading experience.
Report from the Front: EPUB3
Authors: Freese Eric
Published: October 2011

In 2010, the IDPF chartered a working group to update the EPUB specification to more accurately reflect the demands and expectations of a quickly growing marketplace. The specific items to be addressed included:

Greater rich media (audio and video) and interactivity support (programmatic content, such as would be needed to implement a quiz or crossword puzzle).

Enhanced global language support for the character sets, Ruby markup, and typographic rules needed for reading systems in CJK geographies (including but not limited to special line-breaking rules and vertical writing direction).

Enhanced article support in order to support magazines and newspapers.

Enhanced metadata support beyond embedded publication metadata.

Ability to convey page-level layouts and target multiple display surface sizes in a single publication.

Enhanced navigation support.

Alignment with broadly-adopted Web standards as implemented by modern browsers.

Support for annotation.

Native support for mathematics.

Support for book-specific structures, such as glossaries, note reference systems and advanced cross-reference systems.

Improved accessibility support.

Mechanism for adding industry specific extensions in an interoperable manner.

Define relationships to approved national and international standards.

Define mechanism for including advertising.

This paper will discuss those changes and present the author's view on whether the goals set forth by the IDPF were met. The potential impacts on the market from both the publisher and consumer view will also be considered.
Tag Libraries for XSLT and XQuery
Authors: Hennum Erik , Zholudev Vyacheslav
Published: October 2011

XML has mature tools for validation, transformation, and query, but current tools require a level of programming skills that many users who need dynamic documents do not have. Using the organizational pattern of tag libraries (borrowed from Java tag libraries), we propose to divide responsibilities for dynamic documents between two classes of people. Tag-library developers implement query, transformation, or component formatting for predefined tags in a library; document authors create dynamic documents by embedding elements from the tag library in HTML, XSL-FO, or other documents; when the document is processed, elements from the tag library are replaced by automatically generated content. A callback mechanism allows the document author to pass document fragments to the tag library for parameterization. Document authors can use tag libraries in ways not foreseen by the tag library developers and can combine tag libraries from different developers. A robust tag-library solution will foster better collaboration between XML developers and creators of XML documents.
TagAl
Authors: Johnsen Lars G. , Huitfeldt Claus
Published: October 2011

This paper takes its point of departure in an overview of the overlap problem, and of proposed solutions to that problem. We then look at some analogies between bracketed markup notations and rules for well-formedness and structuring of simple parenthetical expressions. We propose a method for building lattices from marked up documents with and without overlap, and for generating, from these lattices, document models in the form of trees for XML documents, and in the form of GODDAGs for documents with overlap. It turns out that one and the same method can be used for generating both kinds of models, and we argue that lattices can also be used to implement well-formedness constraints for both kinds of documents. Finally, we discuss and compare some of the algebraic features of the document models, and the relations between them.
Including XSLT stylesheets testing in continuous integration process
Authors: Mercier Benoit
Published: October 2011

XSLT stylesheets are just like any other programming language code units: they need to be written, debugged, refactored and tested. In these days of « Agility », refactoring and continuous integration play major roles in development process. How to assert that XSLT stylesheets refactoring are still producing correct outputs? How to early detect defects? This paper proposes a practical approach to include XSLT stylesheets testing in continuous integration process, based on XSpec, a Behavior Driven Development (BDD) framework for XSLT, and on Java helpers provided by Jxsl, a Java XSL code library.
REST for document resource nodes: IPSA RE for the arcs
Authors: Perry Walter E.
Published: October 2011

The IPSA RE (Identity, Provenance, Structure, Aptitude, Revision, and Events) architecture describes and processes the linkages that relate document resources within a network or graph of nodes. The architecture can be formalized by manipulation of document resource nodes by each of the four fundamental RESTful verbs. The system under development handles identity authentication by realizing identity as a chain of provenance or as a unique structure of context rather than relying on any internal attributes of a node to establish either that node’s identity or the identity of any entity for which that node is a proxy.
Abstract generic microformats for coverage, comprehensiveness, and adaptability
Authors: Piez Wendell
Published: October 2011

Markup languages that attempt not only to support particular applications, but to provide encoding standards for decentralized communities, face a particular problem: how do they adapt to new requirements for data description? The most usual approach is a schema extensibility mechanism, but many projects avoid them, since they fork the local application from the core tag set, complicating implementation, maintenance, and document interchange and thus undermining many of the advantages of using a standard. Yet the easy alternative, creatively reusing and abusing available elements and attributes, is even worse: it introduces signal disguised as noise, degrades the semantics of repurposed elements and hides the interchange problem without solving it.

This dilemma follows from the way we have conceived of our models for text. If designing an encoding format for one work must compromise its fitness for any other – because the clean and powerful descriptive markup for one kind of text is inevitably unsuitable for another – we will always be our own worst enemies. Yet texts “in the wild” are purposefully divergent in the structures, features and affordances of their design at both micro and macro levels. This suggests that at least in tag sets intended for wide use across decentralized communities, we must support design innovation not only in the schema, but in the instance – in particular documents and sets of documents. By defining, in the schema, a set of abstract generic elements for microformats, we can appropriate tag abuse (at one time making it unnecessary and capturing the initiative it represents), expose significant and useful semantic variation, and support bottom-up development of new semantic types.
XML out — reducing clutter
Authors: Quin Liam R. E.
Published: October 2011

Why is XML a pain to produce? Those among us who’ve produced documents in XML for years may hardly think about the process, but programmers from application development or systems programming may find it alien, frustrating, and a source of errors. Perhaps a simple API for common programming languages like PHP and JavaScript would relieve their pain.
Secured Management of Online XML Document Services through Structure Preserving Asymmetric Encryption
Authors: Vion-Dury Jean-Yves
Published: October 2011

Externalizing document management is a problem when individual or corporate privacy is to be ensured. Provided that the decryption key is not known from service side, pure storage/archiving of encrypted documents is highly secure, but of poor interest as no operation can be performed on hosted data. Thus, current document management systems offer restricted privacy mechanisms, roughly based on secured communication channels and sometimes encrypted storage. However, many value-added processing operations require decrypting the document, and no formal guaranty is granted regarding the safety of system behaviors. As an example of known issue, there is the problem of data remanence (persisting information on disk after file system deletion), bugs or viruses acting on various level of the software architecture. This paper describes a method to allow restricted (but yet meaningful) ways of processing encrypted XML documents without needing decryption phase. The encryption process we propose allows isomorphic encryption of data (XML document owned by customers) and operator transformations (verification and transformation operated by the Service Provider) in such a way that full secrecy is ensured simply because the decoding key is not known by the Service Provider. Once transformed, operators can handle encrypted documents with equivalent results up to the decryption operation.
Tougher Educational Exam Leading to Worse Selection
Authors: de Carvalho Andrade Eduardo , de Castro Luciano I.
Published: October 2011

A parallel of education with transformative processes in standard markets suggest that a more severe control of the quality of the output will improve the overall quality of the education. This paper shows a somehow counterintuitive result: an increase in the exam diffculty may reduce the average quality (productivity) of selected individuals. Since the exam does not verify all skills, when its standard rises, candidates with relatively low skills emphasized in the test and high skills demanded in the job may no longer qualify. Hence, an increase in the testing standard may be counterproductive. One implication is that policies should emphasize alignment between the skills tested and those required in the actual jobs, rather than increase exams’ diffculty.
Quantification of the unknown HONO daytime source and its relation to NO2
Authors: Sörgel M. , Regelin E. , Bozem H. , Diesch J.-M. , Drewnick F. , Fischer H. , Harder H. , Held A. , Hosaynali-Beygi Z. , Martinez M. , Zetzsch C.
Published: October 2011

Abstract. During the DOMINO (Diel Oxidant Mechanism In relation to Nitrogen Oxides) campaign in southwest Spain we measured simultaneously all quantities necessary to calculate a photostationary state for HONO in the gas phase. These quantities comprise the concentrations of OH, NO, and HONO and the photolysis frequency of NO2, j(NO2) as a proxy for j(HONO). This allowed us to calculate values of the unknown HONO daytime source. This unknown HONO source, normalized by NO2 mixing ratios and expressed as a conversion frequency (% h−1), showed a clear dependence on j(NO2) with values up to 43% h−1 at noon. We compared our unknown HONO source with values calculated from the measured field data for two recently proposed processes, the light-induced NO2 conversion on soot surfaces and the reaction of electronically excited NO2* with water vapour, with the result that these two reactions normally contributed less than 10% (<1% NO2 + soot + hν; and <10% NO2* + H2O) to our unknown HONO daytime source. OH production from HONO photolysis was found to be larger (by 20%) than the "classical" OH formation from ozone photolysis (O(1D)) integrated over the day.
Carbonaceous aerosols in China: top-down constraints on primary sources and estimation of secondary contribution
Authors: Fu T.-M. , Cao J. J. , Zhang X. Y. , Lee S. C. , Zhang Q. , Han Y. M. , Qu W. J. , Han Z. , Zhang R. , Wang Y. X. , Chen D. , Henze D. K.
Published: October 2011

Abstract. We simulate elemental carbon (EC) and organic carbon (OC) aerosols in China and compare model results to surface measurements at Chinese rural and background sites, with the goal of deriving "top-down" emission estimates of EC and OC, as well as better quantifying the secondary sources of OC. We include in the model state-of-the-science Chinese "bottom-up" emission inventories for EC (1.92 Tg C yr−1) and OC (3.95 Tg C yr−1), as well as updated secondary OC formation pathways. The average simulated annual mean EC concentration at rural and background site is 1.1 μg C m−3, 56% lower than the observed 2.5 μg C m−3. The average simulated annual mean OC concentration at rural and background sites is 3.4 μg C m−3, 76% lower than the observed 14 μg C m−3. Multiple regression to fit surface monthly mean EC observations at rural and background sites yields best estimate of Chinese EC source of 3.05 ± 0.78 Tg C yr−1. Based on the top-down EC emission estimate and observed seasonal primary OC/EC ratios, we estimate Chinese OC total emissions to be 6.67 ± 1.30 Tg C yr−1. Using these top-down estimates, the simulated average annual mean EC concentration at rural and background sites significantly improved to 1.9 μg C m−3. However, the model still significantly underestimates observed OC in all seasons (simulated average annual mean OC at rural and background sites is 5.4 μg C m−3), with little skill in capturing the spatiotemporal variability. Secondary formation accounts for 21% of Chinese annual mean surface OC in the model, with isoprene being the most important precursor. In summer, as high as 62% of the observed surface OC may be due to secondary formation in eastern China. Our analysis points to three shortcomings in the current bottom-up inventories of Chinese carbonaceous aerosols: (1) the anthropogenic source is severely underestimated, particularly for OC; (2) there is a missing source in western China, likely associated with the use of biofuels or other low-quality fuels for heating; and (3) sources in fall are not well represented, either because the seasonal shifting of emissions and/or secondary formation are poorly captured or because specific fall emission events are missing. More regional measurements with better spatiotemporal coverage are needed to resolve these shortcomings.
A modified drought index for WMO RA VI
Authors: Pietzsch S. , Bissolli P.
Published: October 2011

Abstract. Drought is a phenomenon which can cause large economical impact even in Europe. To assess the magnitude and the spatial extension of drought events, it is important to have a standardized drought index which is applicable for a large climatically heterogeneous region like Europe or the WMO RA VI Region (Europe and the Middle East). Such an index should describe the drought phenomenon adequately, but it should also be derivable from meteorological quantities which are easily and timely available in whole Europe. In a first investigation, some candidates for drought indices were chosen, compared and assessed for applicability in whole Europe. The most appropriate one seems to be the widely known Standardized Precipitation Index (SPI) which is a standardized and handy measurement of drought for any location and requires nothing but precipitation data. However, it has turned out that for some places in the RA VI Region, notably in arid regions in summer, the SPI does not always provide reasonable or easily interpretable results. For that reason, some modifications of the SPI have been tried out and tested statistically. It seems that the gamma distribution of precipitation which is used for computation of the SPI is in fact the most appropriate one and other distributions have not improved the results substantially. On the other hand a so called zero correction, which sets very small precipitation totals to dry values, only dependent on the precipitation distribution, but independent on the individual location delivers more reasonable results. Maps of the new modified drought index and its anomalies from the climate normal are produced quasi-operationally and distributed via the Internet each month. The drought monitoring is part of the monitoring programme of the WMO RA VI Pilot Regional Climate Centre on Climate Monitoring (RCC-CM) hosted by the German Meteorological Service (Deutscher Wetterdienst, DWD), and the maps can be found on its present RCC-CM platform (http://www.dwd.de/rcc-cm).
Seasonal and interannual variability of physical and biological dynamics at the shelfbreak front of the Middle Atlantic Bight: nutrient supply mechanisms
Authors: He R. , Chen K. , Fennel K. , Gawarkiewicz G. G. , McGillicuddy Jr D. J.
Published: October 2011

Abstract. A high-resolution, 3-dimensional coupled biophysical model is used to simulate ocean circulation and ecosystem variations at the shelfbreak front of the Middle Atlantic Bight (MAB). Favorable comparisons between satellite observations and model hindcast solutions from January 2004 to November 2007 indicate the model has intrinsic skills in resolving fundamental physical and biological dynamics at the MAB shelfbreak. Seasonal and interannual variability of ocean physical and biological states and their driving mechanisms are further analyzed. The domain-wide upper water column nutrient content is found to peak in late winter-early spring. Phytoplankton spring bloom starts 1–2 months later, followed by zooplankton bloom in early summer. Our analysis shows the variability of shelfbreak nutrient supply is controlled by local mixing that deepens the mixed layer and injects deep ocean nutrients into the upper water column and alongshore nutrient transport by the shelfbreak jet and associated currents. Nutrient vertical advection associated with the shelfbreak bottom boundary layer convergence is another significant contributor. Spring mean nutrient budget diagnostics along the Nantucket transect are compared between nutrient rich 2004 and nutrient poor 2007. Physical advection and diffusion play the major role in determining strong interannual variations in shelfbreak nutrient content. The biological (source minus sink) term is very similar between these two years.
Sea-to-air and diapycnal nitrous oxide fluxes in the eastern tropical North Atlantic Ocean
Authors: Kock A. , Schafstall J. , Dengler M. , Brandt P. , Bange H. W.
Published: October 2011

Abstract. Sea-to-air and diapycnal fluxes of nitrous oxide (N2O) into the mixed layer were determined during three cruises to the upwelling region off Mauritania. Both fluxes were elevated close to the shelf break, but elevated sea-to-air fluxes reached further offshore as a result of the offshore transport of upwelled water masses. To calculate a mixed layer budget for N2O we compared the regionally averaged sea-to-air and diapycnal fluxes and estimated the potential contribution of other processes, such as vertical advection and biological N2O production in the mixed layer. Using common parameterizations for the gas transfer velocity, the comparison of the average sea-to-air and diapycnal N2O fluxes indicated that the mean sea-to-air flux is about three to four times larger than the diapycnal flux. Vertical and horizontal advection or biological production were found not sufficient to close the mixed layer budget. Instead, the sea-to-air flux, calculated using a parameterization that takes into account the attenuating effect of surfactants on gas exchange, is in the same range as the diapycnal flux. This indicates that common parameterizations for the gas transfer velocity might overestimate the air-sea gas exchange within highly productive upwelling zones.
Denitrification and inference of nitrogen sources in the karstic Floridan Aquifer
Authors: Heffernan J. B. , Albertin A. R. , Fork M. L. , Katz B. G. , Cohen M. J.
Published: October 2011

Abstract. Aquifer denitrification is among the most poorly constrained fluxes in global and regional nitrogen budgets. The few direct measurements of denitrification in groundwaters provide limited information about its spatial and temporal variability, particularly at the scale of whole aquifers. Uncertainty in estimates of denitrification may also lead to underestimates of its effect on isotopic signatures of inorganic N, and thereby confound the inference of N source from these data. In this study, our objectives are to quantify the magnitude and variability of denitrification in the Upper Floridan Aquifer (UFA) and evaluate its effect on N isotopic signatures at the regional scale. Using dual noble gas tracers (Ne, Ar) to generate physical predictions of N2 gas concentrations for 112 observations from 61 UFA springs, we show that excess (i.e. denitrification-derived) N2 is highly variable in space and inversely correlated with dissolved oxygen (O2). Negative relationship between O2 and δ15NNO3 across a larger dataset of 113 springs, well-constrained isotopic fractionation coefficients, and strong 15N : 18O covariation further support inferences of denitrification in this uniquely organic-matter-poor system. Despite relatively low average rates, denitrification accounted for 32% of estimated aquifer N inputs across all sampled UFA springs. Back-calculations of source δ15NNO3 based on denitrification progression suggest that isotopically-enriched nitrate (NO3−) in many springs of the UFA reflects groundwater denitrification rather than urban- or animal-derived inputs.
Masked millennial-scale climate variations in South West Africa during the last glaciation
Authors: Hessler I. , Dupont L. , Handiani D. , Paul A. , Merkel U. , Wefer G.
Published: October 2011

Abstract. Large and abrupt shifts between extreme climatic conditions characterise the last glacial and deglacial period and are thought to be transmitted by the atmospheric and oceanic circulation. Millennial-scale climatic shifts associated with North Atlantic Heinrich Stadials (HSs) are thought to be closely related to a reduction of the Atlantic Meridional Overturning Circulation (AMOC), which lead to the accumulation of heat in the South Atlantic and a southward shift of the Intertropical Convergence Zone (ITCZ). Due to the linkage between the oceans and the atmosphere it is assumed that HSs also influence the vegetation composition in the African tropics. To address the connection between tropical African vegetation development and high-latitude climate change we present a high-resolution marine pollen record from ODP Site 1078 (off Angola) covering the period 50–10 ka BP. Although several tropical African vegetation and climate reconstructions indicate an impact of HSs on the African subcontinent, our vegetation record shows no response. Model simulations conducted with an Earth System Model of Intermediate Complexity (EMIC) including a dynamical vegetation component lead to the hypothesis that the vegetation response during HSs might have been muted by mechanisms that partly cancel each other.
A dynamic continental runoff routing model applied to the last Northern Hemisphere deglaciation
Authors: Goelzer H. , Janssens I. , Nemec J. , Huybrechts P.
Published: October 2011

Abstract. We describe and evaluate a dynamical continental runoff routing model for the Northern Hemisphere that calculates the runoff pathways in response to topographic modifications due to changes in ice thickness and isostatic adjustment. The algorithm is based on the steepest gradient method and takes as simplifying assumption that depressions are filled at all times and water drains through the lowest outlet points. It also considers changes in water storage and lake drainage that become important in the presence of large ice dammed proglacial lakes. Although applicable to other scenarios as well, the model was conceived to study the routing of freshwater fluxes during the last Northern Hemisphere deglaciation. For that specific application we simulated the Northern Hemisphere ice sheets with an existing 3-D thermomechanical ice sheet model, which calculates changes in topography due to changes in ice cover and isostatic adjustment, as well as the evolution of freshwater fluxes resulting from surface ablation, iceberg calving and basal melt. The continental runoff model takes this input, calculates the drainage pathways and routes the freshwater fluxes to the surface grid points of an existing ocean model. This results in a chronology of temporally and spatially varying freshwater fluxes from the Last Glacial Maximum to the present day. We analyse the dependence of the runoff routing to grid resolution and parameters of the isostatic adjustment module of the ice sheet model.
Ground motion predictive modelling based on genetic algorithms
Authors: Yilmaz S.
Published: October 2011

Abstract. This study aims to utilise genetic algorithms for the estimation of peak ground accelerations (PGA). A case study is carried out for the earthquake data from south-west Turkey. The input parameters used for the development of attenuation relationship are magnitude, depth of earthquake, epicentral distance, average shear wave velocity and slope height of the site. Earthquake database compiled by the Earthquake Research Institute of Turkey was used for model development. An important contribution to this study is the slope/hill data included into the dataset. Developed empirical model has a good correlation (R = 0.78 and 0.75 for the training and overall datasets) between measured and estimated PGA values. The proposed model is also compared with local empirical predictive models and its results are found to be reasonable. The slope-hill effect found to be an important parameter for the estimation of PGA.
Using 18th century storm-surge data from the Dutch Coast to improve the confidence in flood-risk estimates
Authors: Baart F. , Bakker M. A. J. , van Dongeren A. , den Heijer C. , van Heteren S. , Smit M. W. J. , van Koningsveld M. , Pool A.
Published: October 2011

Abstract. For the design of cost-effective coastal defence a precise estimate is needed of the 1/10 000 per year storm surge. A more precise estimate requires more observations. Therefore, the three greatest storm surges that hit the northern part of the Holland Coast in the 18th century are reconstructed. The reconstructions are based on paintings, drawings, written records and shell deposits that have recently appeared. The storm-surge levels of these storms have been estimated using numerical modelling of the coastal processes. Here we show how these reconstructions can be used in combination with extreme value statistics to give a more confident estimate of low probability events.