bluuebunny/crossref_metadata_2025 huggingface dataset:
Re-Conceptualising Research
Authors: Fielden Kay
Published: June 2010

Mindfulness is a whole state of being that is not usually linked with academic research in information systems. However if we take Denzin and Lincoln’s (2000; 2003), first qualitative research phase, which is the consideration of the key role of the researcher in socially-situated research, it soon becomes evident that a mindful researcher (Fielden, 2005) is more likely to conduct quality research than one who is not. In this discussion paper the qualities of mindfulness (Fielden, 2005) are explored; Denzin and Lincoln’s (2003) 5-stage qualitative research process is then mapped onto these multiple characteristics of mindfulness; and also onto a timeline for a typical qualitative research process in information systems. The paper concludes with suggestions on how to include mindful practices in research methods and supervision training in information systems, which is a contribution to the literature in this area.
Information Acquisition and Recall in Location-Aware and Search Engine Retrieval Systems
Authors: Matei Sorin Adam , Madsen Lance , Bruno Robert
Published: July 2010

This paper examines the potential cognitive impact of location aware information systems compared to that of search engines using a dual coding and conjoint retention theoretical framework. Supported by virtual reality or mobile devices, location aware systems deliver information that is relevant for a specific location. Research questions and hypotheses formulated under the assumption that location aware systems are better prepared to contextualize and make information memorable are explored using a planned comparison repeated measures 3 (2 treatment; 1 control) x 3 (pre-test, post-test, one week post-test) design. The results indicate that information acquisition in location-aware systems is just as powerful as that facilitated by search engines and that information recall (after 1 week) of facts is superior when using location-aware systems. The findings reinforce and extend dual coding theory suggesting that spatial and three-dimensional indexing can be one of the channels used in indexing and recalling information. The results also indicate that location-aware applications are a promising technology for distributing information in general and for learning in particular.
Clustering Genes Using Heterogeneous Data Sources
Authors: Zeng Erliang , Yang Chengyong , Li Tao , Narasimhan Giri
Published: July 2010

Clustering of gene expression data is a standard exploratory technique used to identify closely related genes. Many other sources of data are also likely to be of great assistance in the analysis of gene expression data. This data provides a mean to begin elucidating the large-scale modular organization of the cell. The authors consider the challenging task of developing exploratory analytical techniques to deal with multiple complete and incomplete information sources. The Multi-Source Clustering (MSC) algorithm developed performs clustering with multiple, but complete, sources of data. To deal with incomplete data sources, the authors adopted the MPCK-means clustering algorithms to perform exploratory analysis on one complete source and other potentially incomplete sources provided in the form of constraints. This paper presents a new clustering algorithm MSC to perform exploratory analysis using two or more diverse but complete data sources, studies the effectiveness of constraints sets and robustness of the constrained clustering algorithm using multiple sources of incomplete biological data, and incorporates such incomplete data into constrained clustering algorithm in form of constraints sets.
Infer Species Phylogenies Using Self-Organizing Maps
Authors: Han Xiaoxu
Published: July 2010

With rapid advances in genomics, phylogenetics has turned to phylogenomics due to the availability of large amounts of sequence and genome data. However, incongruence between species trees and gene trees remains a challenge in molecular phylogenetics for its biological and algorithmic complexities. A state-of-the-art gene concatenation approach was proposed to resolve this problem by inferring the species phylogeny using a random combination of widely distributed orthologous genes screened from genomes. However, such an approach may not be a robust solution to this problem because it ignores the fact that some genes are more informative than others in species inference. This paper presents a self-organizing map (SOM) based phylogeny inference method to overcome its weakness. The author’s proposed algorithm not only demonstrates its superiority to the original gene concatenation method by using same datasets, but also shows its advantages in generalization. This paper illustrates that data missing may not play a negative role in phylogeny inferring. This study presents a method to cluster multispecies genes, estimate multispecies gene entropy and visualize the species patterns through the self-organizing map mining.
Linking Business Strategy and Knowledge Management Capabilities for Organizational Effectiveness
Authors: Smith Trevor A. , Mills Annette M. , Dion Paul
Published: July 2010

The effective management of knowledge resources is a key imperative for firms that want to leverage their knowledge assets for competitive advantage and improved performance. However, most firms do not attain the required performance levels even when programs are in place for managing knowledge resources. Research suggests this shortcoming can be addressed by linking knowledge management to business strategy. This study examines a model that links business strategy to knowledge management capabilities and organizational effectiveness. Using data collected from 189 managers, the results suggest that business strategy is a key driver of knowledge capabilities, and that both business strategy and knowledge capabilities impact organizational effectiveness. Additionally, the authors’ findings indicate that knowledge infrastructure capability is a key imperative for effective knowledge process capability. Managerial implications, limitations and opportunities for future research are also discussed.
The Teachers They Are Becoming
Authors: Robertson Lorayne , Hughes Janette
Published: July 2010

The authors review all aspects of a Language Arts methods course for pre-service teachers, one which employs a multi-literacies pedagogy (The New London Group, 1996) and is taught at a laptop-based university. The course begins with a deliberate immersion into the complexities of multiple literacies, including digital literacy and critical literacy. The authors outline the course assignments, resources and instructional goals to determine how technology impacts pre-service teacher learning and intended future practice. The qualitative data sources include digital artifacts such as digital literacy stories, book talks that focus on social justice issues, and media literacy lessons. In addition, the researchers draw from cross-program data based on teacher candidate reflections and interviews. The data suggest that both the use of digital technology and a multi-literacies pedagogy can help pre-service teachers reflect on personal experiences to develop literacy teaching and learning practices that have transformative elements.
A Different Perspective on Lecture Video-Streaming
Authors: Ronchetti Marco
Published: July 2010

In this paper, the author proposes a paradigm shift in the way video lectures are used in education. Instead of using them to support traditional teaching methods, the author suggests replacing standard lectures with video lectures, opening a space for a more participatory and interactive form of teaching that supports students in deeper understanding. In this paper, the author reviews the literature, discusses the effectiveness of video lectures, and describes a methodology called VOLARE (“Video On Line As Replacement of old tEaching practices”).
Exploring the Enterprise Value of Wikis through Media Choice Theories
Authors: Wagner Christian , Schroeder Andreas , Wong Wing , Shum Anna
Published: July 2010

Wikis are quickly emerging as a new corporate medium for communication and collaboration. They allow dispersed groups of collaborators to asynchronously engage in persistent conversations, the result of which is stored on a common server as a single, shared truth. To gauge the enterprise value of wikis, the authors draw on Media Choice Theories (MCTs) as an evaluation framework. MCTs reveal core capabilities of communication media and their fit with the communication task. Based on the evaluation, the authors argue that wikis are equivalent or superior to existing asynchronous communication media in key characteristics. Additionally argued is the notion that wiki technology challenges some of the held beliefs of existing media choice theories, as wikis introduce media characteristics not previously envisioned. The authors thus predict a promising future for wiki use in enterprises.
Mathematics Learning Community Flourishes in the Cellular Phone Environment
Authors: Daher Wajeeh
Published: July 2010

Researchers point at the importance of nourishing learning communities, which do not merely represent congeniality but rather dig deeply into learning. These learning communities are needed in mobile learning environments. In this article, the author examines the building of a community of middle school students who learned mathematics outside the classroom by carrying out real life activities using their cellular phones. The building of the learning community was led by three 3rd year pre-service teachers majoring in mathematics and computers at Al-Qasemi Academic College of Education. The pre-service teachers worked for 12 weeks with 30 8th grade students who then learned mathematics with their cellular phones and were part of a learning community. The research shows that the use of the cellular phone for learning contributed to their learning, their identity, and their sense of community.
Enterprise Systems Training Strategies
Authors: Coulson Tony , Olfman Lorne , Ryan Terry , Shayo Conrad
Published: July 2010

Enterprise systems (ESs) are customizable, integrated software applications designed to support core business processes. This paper reports research contrasting the relative effectiveness of two strategies for ES end-user training that differentially reflect the Sein, Bostrom, and Olfman (1999) hierarchical knowledge-level model. One strategy— procedural—involves training that targets the three lowest knowledge levels of the model (command-based, tool-procedural, and business-procedural); the other—tool-conceptual—involves training that also includes a higher knowledge level (tool-conceptual). A non-equivalent quasi-experimental design was used for groups of senior business students being trained to use an authentic ES. Performance measures were administered during training and ten days after training concluded. Both experiments demonstrated that training involving the tool-conceptual knowledge level leads to superior mental models, compared with training oriented toward lower knowledge levels, as expressed in the recollection and communication of ES concepts. Tool-conceptual knowledge-level training can be used to promote understanding and communication, and should be incorporated into training strategies for ES.
Flat for the Few, Steep for the Many
Authors: Conaldi Guido
Published: July 2010

A discrepancy exists between the emphasis posed by practitioners on decentralized and non-hierarchical communication in Free Libre/Open Source Software (FLOSS) communities and empirical evidence of their hierarchical structure. To explain this paradox, it is hypothesized firstly that in FLOSS communities local sub-groups exist and are less hierarchical, more decentralized than the whole social network. Secondly, it is hypothesized that the bulk of communication exchanges taking place in the community happens inside local sub-groups formed by the most active community members. The recollection that practitioners have of FLOSS communities to which they participate would then be influenced by the position that they occupy inside those sub-groups. A measure of structural cohesion based on network node connectivity is proposed as an effective method to test whether FLOSS communication networks can be decomposed in nested hierarchies of progressively less centralized sub-groups. The recently introduced measure of weighted rich-club effect is adopted to test for the tendency of the most active community members to control communication by interacting more intensely with each other than with other members of the network. Results from a case study that are consistent with the hypotheses are presented and discussed.
Weaving a Semantic Web Across OSS Repositories
Authors: Berger Olivier , Vlasceanu Valentin , Bac Christian , Dang Quang Vu , Lauriere Stéphane
Published: July 2010

Several public repositories and archives of “facts” about libre software projects, maintained either by open source communities or by research communities, have been flourishing over the Web in recent years. These have enabled new analysis and support for new quality assurance tasks. This paper presents some complementary existing tools, projects and models proposed both by OSS actors or research initiatives that are likely to lead to useful future developments in terms of study of the FLOSS phenomenon, and also to the very practitioners in the FLOSS development projects. A goal of the research conducted within the HELIOS project is to address bugs traceability issues. In this regard, the authors investigate the potential of using Semantic Web technologies in navigating between many different bugtracker systems scattered all over the open source ecosystem. By using Semantic Web techniques, it is possible to interconnect the databases containing data about open-source software projects development, which enables OSS partakers to identify resources, annotate them, and further interlink those using dedicated properties and collectively designing a distributed semantic graph.
Biases in Particle Swarm Optimization
Authors: Spears William M. , Green Derek T. , Spears Diana F.
Published: July 2010

The most common versions of particle swarm optimization (PSO) algorithms are rotationally variant. It has also been pointed out that PSO algorithms can concentrate particles along paths parallel to the coordinate axes. In this paper, the authors explicitly connect these two observations by showing that the rotational variance is related to the concentration along lines parallel to the coordinate axes. Based on this explicit connection, the authors create fitness functions that are easy or hard for PSO to solve, depending on the rotation of the function.
Software Engineering Security Based on Business Process Modeling
Authors: Barjis Joseph
Published: July 2010

Security requirements must be tackled early in software design and embedded in corresponding business process models. As a blueprint for software design, business process models complemented with security requirements will prevent many security breaches. To accomplish secure business process modeling, the underlying method must adhere to certain capabilities and capture actions, actor roles, and interactions. The resultant models should lend themselves to automatic analysis (simulation) to ensure captured security requirements are correctly aligned with the process flow. Thus, the tradeoff between the level of security and business performance can be studied before actual software design. Since unauthorized actions cause security breaches, the software the system’s social setting could be a cradle for defining security requirements. Security requirements can be identified based on the roles, authorities, and obligations of the social actors using the system. This paper introduces a method for security embedded business process modeling. The proposed method draws on two well-tested theoretical foundations—enterprise ontology and organizational semiotics.
Towards Designing E-Services that Protect Privacy
Authors: Yee George O. M.
Published: July 2010

The growth of electronic services (e-services) has resulted in large amounts of personal information in the hands of service organizations like banks, insurance companies, and online retailers. This has led to the realization that such information must be protected, not only to comply with privacy regulations but also and more importantly, to attract clients. One important dimension of this goal is to design e-services that protect privacy. In this paper, the author proposes a design approach that incorporates privacy risk analysis of UML diagrams to minimize privacy risks in the final design. The approach iterates between the risk analysis and design modifications to eliminate the risks until a design is obtained that is close to being risk free.
Engineering Financial Enterprise Content Management Services
Authors: Chiu Dickson K. W. , Hung Patrick C. K. , Kwok Kevin
Published: July 2010

The demand is increasing to replace the current cost ineffective and bad time-to-market hardcopy publishing and delivery of content in the financial world. Financial Enterprise Content Management Services (FECMS) have been deployed in intra-enterprises and over the Internet to network with customers. This paper presents Web service technologies that enable a unified scalable FECMS framework for intra-enterprise content flow and inter-enterprise interactions, combining existing sub-systems and disparate business functions. Additionally, the authors demonstrate the key privacy and access control policies for internal content flow management (such as content editing, approval, and usage) as well as external access control for the Web portal and institutional programmatic users. Through the modular design of an integrated FECMS, this research illustrates how to systematically specify privacy and access control policies in each part of the system with Enterprise Privacy Authorization Language (EPAL). Finally, a case study in an international banking enterprise demonstrates how both integration and control can be achieved.
The Impact of Blogging and Scaffolding on Primary School Pupils' Narrative Writing
Authors: Wong Ruth Mei Fen , Hew Khe Foon
Published: July 2010

Narrative writing is a skill that all primary (elementary) school pupils in Singapore are required to develop in their learning of the English language. However, this is an area in which not all pupils excel. This study investigates if the use of blogging and scaffolding can improve pupils’ narrative writing. Data were gathered from 36 primary five (grade five) pupils through pre-post writing tests, reflection sheets, and interviews. The pre-post writing tests were administered before and after the pupils had completed their blogging activities, while the blogs were used to draft their narrative writings and to comment on their peers’ writings. The teacher also used a writing guide that served as a scaffold to help pupils plan their writing on their blogs. Overall, results showed a statistically significant difference of medium effect size between the pre-post test scores. Pupils’ perceptions of using blogs as a tool for writing were also explored.
Finding Determinants Affecting Distance Education Effectiveness in Terms of Learner Satisfaction and Application Achievement
Authors: Kim Jeong-Wook , Yang Kyung Hoon , Nam Kichan , Kim Sung Tae
Published: July 2010

Distance education has become an important method of extending education to populations that otherwise might be educationally neglected. Distance education in the private sector provides learners with more educational opportunities and widens the range of innovative services with a one-stop educational solution. With distance education, learners can undertake customized education on a more ubiquitous scale. Additionally, information technology allows both trainers and learners to work independently, free from the constraints of location. This study selected the determinants of educational effectiveness from previous literature regarding traditional educational environments, and empirically tested the authors’ hypotheses to examine factors that affected educational effectiveness in terms of learner satisfaction and application performance using a structural equation model. Results show that factors in traditional education are still significant in terms of application performance while certain factors in distance education affect learner satisfaction. The authors expect that this research can serve as a guideline for distance education in the private sector.
Challenges in Researching Portals and the Internet
Authors: Adamson Greg
Published: July 2010

The portal is a point of convergence for many uses and users. Along with the Internet itself, the portal crosses or combines many traditionally separate areas of research, each with its own perspective or perspectives. Such a combination creates a challenge for researchers on how to combine these various perspectives in examining portal and Internet use. This paper examines the methodological challenge by combining five perspectives: historical, technical, media, regulatory and business theory. The paper provides examples of the misunderstanding found regarding concepts that are fundamental and widely understood within a single field, but unknown or misunderstood outside of that field. This misunderstanding between business, technologists, media theorists and regulators contributed to the gulf between Internet investment expectation and the 2000 to 2001 results, the US$4 trillion ‘tech wreck’. Avoiding them will be important to the effective implementation of portal-based business solutions.
WSRP, SOA and UDDI
Authors: Polgar Tony
Published: July 2010

Web Services for Remote Portlets (WSRP) provide solutions for implementation of lightweight Service Oriented Architecture (SOA). UDDI extension for WSRP enables the discovery and access to user facing web services provided by business partners while eliminating the need to design local user facing portlets. Most importantly, the remote portlets can be updated by web service providers from their own servers. Remote portlet consumers are not required to make any changes in their portals to accommodate updated remote portlets. This approach results in easier team development, upgrades, administration, low cost development and usage of shared resources. Furthermore, with the growing interest in SOA, WSRP should cooperate with service bus (ESB).In this paper, the author examines the technical underpinning of the UDDI extensions for WSRP (user facing remote web services) and their role in service sharing among business partners. The author also briefly outlines the architectural view of using WSRP in enterprise integration tasks and the role Enterprise Service Bus (ESB).
Analyzing Communities of Web Services Using Incentives
Authors: Khosravifar Babak , Bentahar Jamal , Moazin Ahmad , Thiran Philippe
Published: July 2010

This paper proposes an effective mechanism dealing with reputation assessment of communities of web services (CWSs) known as societies composed of a number of functionally identical web services. The objective is to provide a general incentive for CWSs to act truthfully. The considered entities are designed as software autonomous agents equipped with advanced communication and reasoning capabilities. User agents request CWSs for services and accordingly rate their satisfactions about the received quality and community responsiveness. The strategies taken by different parties are private to individual agents, and the logging file that collects feedback is investigated by a controller agent. Furthermore, the accurate reputation assessment is achieved by maintaining a sound logging mechanism. To this end, the incentives for CWSs to act truthfully are investigated and analyzed, while the proposed framework defines the evaluation metrics involved in the reputation assessment of a community. In this paper, the proposed framework is described, a theoretical analysis of its assessment and its implementation along with discussion of empirical results are provided. Finally, the authors show how their model is efficient, particularly in very dynamic environments.
Resolving phytoplankton photoprotective : photosynthetic carotenoid ratios on fine scales using in situ spectral absorption measurements
Authors: Eisner Lisa B. , Twardowski Michael S. , Cowles Timothy J. , Perry Mary Jane.
Published: July 2010

Temporal changes in phytoplankton pigments and spectral absorption were evaluated during June 1998 in East Sound, Orcas Island, Washington. High‐resolution vertical profiles of in situ spectral absorption were obtained with a Wet Labs ac‐9 (nine‐wavelength absorption and beam attenuation meter), and pigment concentrations were determined for discrete water samples using high‐performance liquid chromatography (HPLC). Fucoxanthin was the most abundant carotenoid, indicating the dominance of diatoms. We computed a slope index to evaluate changes in shapes of the in situ particulate absorption coefficient (ap) spectra, ap slope = (ap488 − ap532)/(ap676(488 − 532 nm)). A clear linear relationship was seen between ratios of photoprotective : photosynthetic carotenoids (PPC : PSC) and these ap slopes. While pigment package effects may alter the absorption spectra, in our data set we still found a significant relationship between pigment ratios and in situ ap slopes. Retrieval of this relationship was facilitated by the low and relatively constant detrital absorption coefficient (ad) values in our study area. Similar relationships were found between PPC:PSC ratios and the estimated phytoplankton absorption coefficient (aph) spectra. High PPC:PSC ratios and steeper ap slopes were associated with high‐light levels. Our results suggest that in situ absorption measurements can be used to estimate PPC:PSC ratios in areas where the ad contribution is low or can be estimated. These variations in pigment ratios and spectral absorption reflect photoacclimation responses and/or changes in phytoplankton species composition and suggest in situ absorption measurements may be used to estimate pigmentation changes over fine temporal and spatial scales.
Population growth and transport of the red tide dinoflagellate, Noctiluca scintillans, in the coastal waters off Sydney Australia, using cell diameter as a tracer
Authors: Dela-Cruz Jocelyn , Middleton Jason H. , Suthers Iain M.
Published: July 2010

Spatial abundance patterns of the heterotrophic dinoflagellate, Noctiluca scintillans, were investigated along the southeast coast of Australia to address the hypothesis that population growth of Noctiluca is driven by anthropogenic eutrophication. Abundance patterns were related to the immediate physical flow field and not the conditions conducive to growth. Noctiluca cells were advected southward with the East Australian Current, which was the dominant transport vector for the cells in this region. Areas of population growth of Noctiluca were identified by variations in cell‐size distributions. Small cells (<525 µm) were considered to be capable of population growth, in contrast to red tide cells, which are known to be large (<600 µm), senescent, and the end result of a long series of biological and physical processes occurring in temporally and spatially distant water masses. Small cells were therefore considered to be located closer to the region in which growth was stimulated. The proportion of small cells in the samples was significantly correlated with relatively high concentrations of chlorophyll a. Consequently, this relationship was used to show that population growth of Noctiluca may be stimulated by an increase in chlorophyll a due to sewage discharge, although the prevailing hydrological conditions determine the likelihood of such impacts. High chlorophyll a concentrations within estuaries were also found to sustain a stable but low standing stock of Noctiluca, which may seed oceanic stocks. Thus, by examining cell size rather than abundance distributions, we identified and interpreted the variance in the spatial abundance patterns of Noctiluca within a dynamic hydrological environment.
Stimulation of nitrogen fixation in refractory organic sediments by Caulerpa taxifolia(Chlorophyta)
Authors: Chisholm John R. M. , Moulin Pascale
Published: July 2010

Estimates of N2 fixation by substrata associated with the rhizophytic alga Caulerpa taxifolia were obtained using the acetylene reduction method. On average, growth of C. taxifolia enhanced rates of acetylene reduction in underlying dead sea grass sediments by a factor of 28, although the degree of enhancement was variable. The average rate of ethylene production was 3.96 nmol cm‐3 h‐1 (range = 2.5‐6.2 nmol cm‐3 h‐1). There was no apparent stimulation of N2 fixation in substrata collected close to a wastewater outlet. C. taxifolia appears to enhance N2 fixation by releasing photosynthetic product into the rhizosphere, mimicking the behavior of saltwater vascular plants. The excreted organic C activates the fermenting bacterial community, which in turn makes substrates available to the sulfate reducers. The associated microbial reactions create strong reducing conditions that favor N2 fixation, of which many sulfate reducers are capable. Nitrogen fixation can serve to reduce the N deficit that inhibits bacterial decomposition of refractory sea grass waste, thereby enhancing organic matter turnover and nutrient supply to the alga's rhizoids. This process likely assists C. taxifolia to proliferate upon refractory organic sediments in low‐nutrient seawater.
Responses of infaunal populations to benthoscape structure and the potentialimportance of transition zones
Authors: Zajac Roman N. , Lewis Ralph S. , Poppe Lawrence J. , Twichell David C. , Vozarik Joseph , DiGiacomo‐Cohen Mary L.
Published: July 2010

Relationships between population abundance and seafloor landscape, or benthoscape, structure were examined for 16 infaunal taxa in eastern Long Island Sound. Based on analyses of a side‐scan sonar mosaic, the 19.4‐km2 study area was comprised of six distinct large‐scale (> km2) benthoscape elements, with varying levels of mesoscale (km2‐m2) and small‐scale (< m2) physical and biological habitat heterogeneity. Transition zones among elements varied from ~50 to 200 m in width, comprised ~32% of the benthoscape, and added to overall benthoscape heterogeneity. Population abundances of nine taxa varied significantly among the large‐scale elements. Most species were found at high abundances only in one benthoscape element, but three had several foci of elevated abundances. Analyses of population responses to habitat heterogeneity at different spatial scales indicated that abundances of eight taxa varied significantly among spatial scales, but the significant scales were mixed among these species. Relatively large residual variations suggest significant amounts of mesoscale spatial variation were unaccounted for, varying from ~1 km2 to several m2. Responses to transition zones were mixed as well. Abundances of nine taxa varied significantly among transition zones and interiors of benthoscape elements, most with elevated abundances in transition zones. Our results show that infaunal populations exhibit complex and spatially varying patterns of abundance in relation to benthoscape structure and suggest that mesoscale variation may be particularly critical in this regard. Also, transition zones among benthoscape features add considerably to this variation and may be ecological important areas in seafloor environments.
Light scattering properties of marine particles in coastal and open ocean waters asrelated to the particle mass concentration
Authors: Babin Marcel , Morel André , Fournier-Sicre Vincent , Fell Frank , Stramski Dariusz
Published: July 2010

Variations in the spectral scattering coefficient of marine particles [bp(λ)] were measured at 241 locations in oceanic (case 1) and coastal (case 2) waters around Europe. The scattering coefficient at 555 nm normalized to the dry mass of particles [bmp (555)] was, on average, 1.0 and 0.5 m2 g‐1 in case 1 and case 2 waters, respectively. Spectral variations in bp(λ) were, on average, small in all investigated waters. To understand the observed variations in particle scattering, we performed calculations based on the Mie theory with various values for the slope for the Junge‐type size distribution, refractive index, and apparent density of particles (dry weight/wet volume). The latter two were varied according to the type of particles (organic versus mineral) and, for organic ones, as a function of the water content. The higher bmp(555) values in case 1 waters are mainly due to the low apparent density, which results from the organic nature of particles and their elevated water content. In all investigated coastal regions, except for the Baltic Sea, the low bmp(555) values can be explained by the dominant presence of mineral particles, characterized by a high density that counterbalances the effect of a higher refractive index. In the Baltic Sea, bmp(555) was similar to values found in other coastal waters despite the fact that particles were dominantly organic, which may result from higher absorption relative to scattering. A smaller than expected increase of bp(λ) toward short wavelengths is attributed to significant absorption that increases toward the shorter wavelengths and reduces scattering, whether particles are living, detrital, or mineral. Our analyses suggest that the determination of bmp may be significantly sensitive to the porosity of the filter used to assess the dry mass of particles.
Modulation of wave forces on kelp canopies by alongshore currents
Authors: Gaylord Brian , Denny Mark W. , Koehl Mimi A. R.
Published: July 2010

The predominant view of the canopy‐forming kelp's mechanical response to water motion is that they sway passively under waves such that they are only rarely stretched out in flow, which reduces relative fluid velocities and decreases the applied force. Such a view is an appropriate first‐order approximation but becomes conceptually problematic in the face of the net surface velocities (Stokes drift) that arise under waves of all but infinitesimal height, since such flows can tug organisms into fully extended positions, allowing forces to act unabated. Focusing on Nereocystis luetkeana, the bull kelp, this study examines quantitatively the capacity of alongshore currents to mitigate the consequences of Stokes drift by maintaining canopy‐forming macroalgae in “neutral” positions with regard to the onshore‐offshore orbits of the waves. Results indicate that alongshore currents can indeed substantially reduce the forces imposed on canopy‐forming kelps, as well as decrease the levels of wave damping that result from the interaction of these organisms with the passing fluid.
High‐frequency internal waves in large stratified lakes
Authors: Boegman L. , Imberger J. , Ivey G. N. , Antenucci J. P.
Published: July 2010

Observations are presented from Lake Biwa and Lake Kinneret showing the ubiquitous and often periodic nature of high‐frequency internal waves in large stratified lakes. In both lakes, high‐frequency wave events were observed within two distinct categories: (1) Vertical mode 1 solitary waves near a steepened Kelvin wave front and vertical mode 2 solitary waves at the head of an intrusive thermocline jet were found to have wavelengths ~64–670 m and ~13–65 m, respectively, and were observed to excite a spectral energy peak near 10-3 Hz. (2) Sinusoidal vertical mode 1 waves on the crests of Kelvin waves (vertically coherent in both phase and frequency) and bordering the thermocline jets in the high shear region trailing the vertical mode 2 solitary waves (vertically incoherent in both phase and frequency) were found to have wavelengths between 28–37 and 9–35 m, respectively, and excited a spectral energy peak just below the local maximum buoyancy frequency near 10−2 Hz. The waves in wave event categories 1 and 2 were reasonably described by nonlinear wave and linear stability models, respectively. Analysis of the energetics of these waves suggests that the waves associated with shear instability will dissipate their energy rapidly within the lake interior and are thus responsible for patchy turbulent events that have been observed within the metalimnion. Conversely, the finite‐amplitude solitary waves, which each contain as much as 1% of the basinscale Kelvin wave energy, will propagate to the lake perimeter where they can shoal, thus contributing to the maintenance of the benthic boundary layer.
Measurement of submarine groundwater discharge in Kahana Bay, O'ahu, Hawai'i
Authors: Garrison G. H. , Glenn C. R. , McMurtry G. M.
Published: July 2010

Submarine groundwater discharge (SGD) is neither well understood nor commonly investigated in HawaiÂ'i, but it is recognized as a potential pollution source to coastal environments. Between 1998 and 2000, this study located and quantified both total SGD and the terrestrial SGD fraction (tgw) in Kahana Bay, OÂ'ahu. CTD casts were used to profile the water structure and identify potential areas of SGD impact in the bay. Lee‐type seepage meters were used to measure SGD rates and collect samples of SGD directly. Radon−222, Si, Cl−, and total alkalinity (Ta) were used as natural tracers to measure the terrestrial groundwater fraction within SGD. Nutrient concentrations were also measured to calculate total nutrient fluxes into the bay via SGD. Ninety percent of the SGD in Kahana Bay occurs in the inner bay within 1 km of the shoreline. The average total SGD flux measured was 90 × 106 L d−1, 16% of which was terrestrial groundwater. By comparison, the average annual surface runoff from Kahana River is 90.7 106 L d−1. Estimated fluxes of total dissolved phosphorus and nitrogen by SGD to the bay were 500 and 200% greater than fluxes via surface runoff, respectively. Thus, SGD in Kahana Bay has proved to be a significant source of both freshwater and total nutrient input comparable to that from the surface runoff of Kahana River.
Evaporation determined by the energy‐budget method for Mirror Lake, New Hampshire
Authors: Winter Thomas C. , Buso Donald C. , Rosenberry Donald O. , Likens Gene E. , Sturrock Alex Jr. M. , Mau David P.
Published: July 2010

Evaporation was determined by the energy‐budget method for Mirror Lake during the open water periods of 1982–1987. For all years, evaporation rates were low in spring and fall and highest during the summer. However,the times of highest evaporation rates varied during the 6 yr. Evaporation reached maximum rates in July for three of the years, in June for two of the years, and in August for one of the years. The highest evaporation rate during the 6‐yr study was 0.46 cm d−1 during 27 May–4 June 1986 and 15–21 July 1987. Solar radiation and atmospheric radiation input to the lake and long‐wave radiation emitted from the lake were by far the largest energy fluxes to and from the lake and had the greatest effect on evaporation rates. Energy advected to and from the lake by precipitation, surface water, and ground water had little effect on evaporation rates. In the energy‐budget method, average evaporation rates are determined for energy‐budget periods, which are bounded by the dates of thermal surveys of the lake. Our study compared evaporation rates calculated for short periods, usually ~1 week, with evaporation rates calculated for longer periods, usually ~2 weeks. The results indicated that the shorter periods showed more variability in evaporation rates, but seasonal patterns, with few exceptions, were similar.
Detection and partial characterization of dissolved glycoproteins in oceanic waters
Authors: Yamada Namiha , Tanoue Eiichiro
Published: July 2010

The widespread occurrence of dissolved proteins as well as porin proteins was confirmed in water columns at five stations located in the North Pacific, the northern North Pacific, and the Bering Sea, where no investigation has heretofore been made with regard to dissolved protein. The major dissolved proteins detected in this study were determined to be glycosylated, based on the detection of an aldehyde group formed by the periodate oxidation of the electrophoretically separated dissolved proteins. The cross reactivity against lectins to the glycoproteins indicated that there were two types of linkage between sugar chain and polypeptide; one was an N‐linked sugar chain and the other was an O‐linked sugar chain. In this study, a previously reported dissolved protein with an apparent molecular weight of 40 kilodaltons was identified as an OmpA‐like protein, not a porin protein but a major outer membrane protein of most pathogenic gram‐negative bacteria. The survival of porin proteins in dissolved organic matter is thought to give rise to the resistant structure of these proteins; consequently, unidentified dissolved proteins could also be porin proteins. However, the occurrences of glycoproteins and an OmpA‐like protein demonstrated that proteins other than porin proteins account for the majority of dissolved proteins, since no glycosylated porin protein is known. There must therefore be an additional mechanism by which dissolved proteins are protected from biological attack. The possibility that glycoprotein sugar chains can help preserve other dissolved proteins in seawater, as well as the glycoproteins themselves, is discussed herein.
Bioavailability of dissolved organic phosphorus in the euphotic zone at Station ALOHA, North Pacific Subtropical Gyre
Authors: Björkman Karin M. , Karl David M.
Published: July 2010

The biologically available phosphorus (BAP) and soluble reactive phosphorus (SRP) concentrations and phosphorus (P) uptake rates within the euphotic zone (0–175 m) were measured on eight cruises between October 2000 and November 2001 to Sta. ALOHA (22.75°N, 158°W) in the North Pacific Subtropical Gyre. The SRP concentrations in the upper 100 m ranged from 7 to 84 nmol P L−1, with a mean concentration of 41 nmol P L−1 (SE = 4,n = 40). The BAP pool consistently exceeded the SRP pool by factors of 1.4–2.8 in the upper 100 m, the additional P amounting to 7–15% of the dissolved organic P (DOP) pool, assuming that the measured SRP pool is fully bioavailable. Mean P uptake rates, based on SRP concentrations, ranged from 0.8 to 4.0 nmol P L−1 d−1, with the highest rates in the surface waters decreasing with increasing depth. Mean P uptake rates that are based on BAP concentrations ranged from 0.6 to 8.0 nmol P L−1 d−1, with a maximum at ~45 m, the depth corresponding to the highest adenosine‐5′‐triphosphate concentrations and highest DOP: SRP ratios. In the 125–175‐m depth interval, SRP concentrations increased from 74 to 200 nmol P L−1 and DOP declined by an average of 70 nmol P L−1. Because of the lower DOP concentrations at these depths, the contribution to BAP from the DOP pool increased to ~25%. These results indicate that the microbial community utilizes combined P compounds for their P nutrition simultaneously and, on average, uses them to the same extent as SRP in the upper water column. These results have important implications for P biogeochemistry in low‐inorganic nutrient environments.
Effect of iron limitation on the cadmium to phosphorus ratio of natural phytoplankton assemblages from the Southern Ocean
Authors: Cullen Jay T. , Chase Zanna , Coale Kenneth H. , Fitzwater Steve E. , Sherrell Robert M.
Published: July 2010

There is considerable interest in the biogeochemical cycling of cadmium (Cd) and phosphate (PO4) in surface waters, driven in part by the ongoing development of a paleonutrient proxy that utilizes Cd preserved in fossil planktonic foraminifera to determine past PO4 utilization efficiencies in ocean surface waters. The present article reports the results of a field study into the effects of Fe limitation on the Cd : P composition of natural assemblages of marine phytoplankton in the Antarctic Zone of the Pacific sector of the Southern Ocean. Iron enrichment to shipboard incubation bottles led to increases in community growth rate and final biomass. After 10.7 d of incubation, the climax community was dominated by large diatoms of the genus Fragillariopsis, Pseudonitzschia , and Nitzschia. Direct measurements of phytoplankton metal : P ratios from controlled shipboard experiments indicate that Cd : P, Co: P, and Zn : P ratios decreased from control values with increasing initial dissolved Fe concentrations in the incubation bottles, by factors of ~2–10 at highest Fe additions. We suggest that the effect of Fe limitation on resident diatoms is to decrease growth rate, leading to elevated cellular Cd content. The dissolved Cd : P ratio in iron‐limited surface waters of the Southern Ocean may, therefore, respond to the supply of Fe to the resident phytoplankton community, which has implications for the developing paleonutrient proxy. We suggest that the biological uptake of Cd and P is independent of the dissolved Cd: PO4 ratio. As a consequence, the results argue against the use of empirical Rayleigh fractionation models or models with fixed phytoplankton uptake ratios to account for regional variability in surface water dissolved Cd : PO4.
Ecosystem metabolism controls nitrogen uptake in streams in Grand Teton National Park, Wyoming
Authors: Hall Robert Jr. O. , Tank Jennifer L.
Published: July 2010

Streams and rivers regulate nitrogen transport (N) to downstream ecosystems. Rates of N uptake can be high in streams, but controls on the variation in uptake rates of N among streams are not known. We measured ammonium (NH+4) and nitrate (NO−3 ) uptake velocities (Vf) and compared these with whole‐reach estimates of gross primary production (GPP) and community respiration (CR) in 11 low‐nitrogen streams in Grand Teton National Park, Wyoming. We predicted that increased metabolism would positively relate to higher N demand because of stoichiometric N requirements associated with carbon fixation. Rates of GPP and CR explained 82% of variation in NH+4 Vf. Nitrate Vf was controlled by GPP, not CR, with GPP explaining 75% of variation in NO−3 Vf. Nitrate concentrations did not increase downstream during NH+4 addition in all streams, including streams with zero NO−3 uptake, suggesting low nitrification rates relative to NH+4 uptake. Using a stoichiometric model, we show that areal N uptake estimated from microbial and algal production was similar to measured areal N uptake. High primary production could be a prerequisite for streams exhibiting high NO−3 uptake rates.
Resuspension of phytodetritus from the sea floor: A laboratory flume study
Authors: Beaulieu Stace E.
Published: July 2010

Mass settling of phytoplankton can result in the accumulation of a layer of phytodetritus on the sea floor. In order to determine the fate of this organic matter, we must know whether the phytodetritus may be returned to the water column by resuspension. This study was designed to measure the critical bed shear stress ( τ0crit) for resuspension of phytodetritus and to test whether τ0crit differs (1) among types of phytodetritus with different phytoplankton species composition and (2) within type among ages. Phytodetritus was created from cultured Skeletonema costatum and from natural assemblages dominated by Chaetoceros spp., collected near the end of diatom blooms in Cape Cod Bay and Woods Hole, Massachusetts. Resuspension of phytodetritus decomposed 1‐ to 11‐d was measured in a laboratory flume. Overall, τ0crit for the diatom‐derived detritus ranged by a factor of four (0.018–0.068 N m−2), with significant differences in τ0crit among types and ages of phytodetritus. Reasons for these differences are suggested, such as species‐specific differences in size, shape, porosity, and stickiness of the detrital matrix, as well as changes in these parameters that occurred during decomposition. Values for critical shear velocity, which ranged from 0.4 to 0.6 cm s−1 for Chaetoceros‐derived detritus and from 0.5 to 0.8 cm s−1 for Skeletonema‐derived detritus, validated indirect estimates from field studies. An interesting finding with special relevance in lake and coastal systems was the importance of wave‐forced resuspension, suggesting that coupling of settled phytodetritus and other sticky organic flocs to the water column is enhanced by waves.