bluuebunny/crossref_metadata_2025 huggingface dataset:
Designing, Implementing, and Evaluating User-centered and Citizen-centered E-government
Authors: Jaeger Paul T. , Bertot John Carlo
Published: May 2010

The effectiveness of user interactions and engagement with e-government hinges on the extent to which the information and services being offered are user-centered, and in particular citizen-centered. E-government is not effectively serving users if they cannot find the information and services that they seek due to organizational, educational, policy, or management issues; do not have the skills to properly interact with e-government; do not understand the results that they get; or do not trust the information that they receive. As such, user-centered design and evaluation must be a key consideration in the development and management of e-government. Building on a range of previous research by the authors, this chapter will examine the issues of the designing for, evaluation of, and research about user-centered e-government and implications for e-government policy and management.
Reducing the Administrative Burden by Online Information and Referral Services
Authors: Lluis de la Rosa Josep , Rovira Mercè , Beer Martin , Montaner Miquel , Gibovic Denisa
Published: May 2010

Public Authorities have increasing difficulties in providing timely and accurate information in response to the wide variety of citizens’ enquiries to which they are expected to respond. These often require the citizen to be redirected to elsewhere as the query refers to areas of responsibility of other Authorities. This often leads to frustration and wasted time for the citizen, who has to repeatedly explain their query, before obtaining a satisfactory answer. The Information and Referral Services (I&R) are created to help the citizen. This chapter demonstrates how online I&R can help to reduce the administrative burdens while improving the overall quality of service provided, increasing its availability to full 24/7, and significantly reducing the overall cost to the administration. It is shown the case of Community Answers, in Greenwich, Massachusetts, USA, where the online approach has helped to reduce by a third the required to man telephones while the number of calls increased by 25% between 2000 and 2008. That cased is compared with our own experiences with the Call Centre of the city of Terrassa, Catalonia, Europe, where the service with the on-line I&R has attended a third more questions in the years 2007 and 2008 compared to 2006 without additional costs and similar satisfaction as a result of the adoption of the results of the iSAC6+ European project for the deployment of open source I&R on-line platforms.
Evaluation of E-government Services
Authors: Yeh Shang-Ching , Chu Pin-Yu
Published: May 2010

Do e-government services meet citizens’ needs? This chapter examines the performance of e-government services from a citizen-centric perspective. This chapter, taking the Kaohsiung Citizen Electronic Complaint System (KCECS) in Taiwan as a case study, identifies satisfaction and service quality as evaluation indicators when assessing e-government services. The empirical results show that citizens perceive moderately positive satisfaction toward the e-complaint service, and that a citizen-centric approach for evaluating e-government service is desirable. Complaint resolving ability makes the most contribution to the overall satisfaction of e-complaint service, but remains the top priority for improvement of the KCECS. Some solutions are proposed to help public officials to meet citizens’ needs and thus better serve citizens.
E-Government and Opportunities for Participation
Authors: Gil-Garcia J. Ramon , González Miranda Fernando
Published: May 2010

Electronic government has been considered a powerful strategy for administrative reform. Identified benefits from e-government are numerous and range from efficiency and effectiveness to transparency and democratic participation. However, only a few studies focus on the potential of information technologies (IT) to promote citizen participation in government affairs. This participation could be conceptualized in many different ways, from the possibility of submitting a request or question to actively participating in decision-making and voting online. In some developing countries, opportunities for citizen participation are still very limited and information technologies have the potential to expand these communication channels. Based on an analysis of the 32 state portals in Mexico, this chapter proposes an index of citizen participation opportunities, ranks the portals according to this index, and explores some of the determinants of the availability of these participation opportunities through the case of the Mexican state of Michoacán. We argue that assessing the different channels for citizen participation available through e-government Web sites is an important first step for understanding the relationships between government and citizens. Citizen initiated contacts and participation cannot exist if communication channels are limited or nonexistent.
Participatory E-Planning
Authors: Aikins Stephen Kwamena
Published: May 2010

This chapter discusses the importance of leveraging information technology to link theory and practice of participatory planning. Citizen participation in urban planning and development processes is an important exercise that enriches community involvement in local planning decision-making. The advancement in Geographic Information Systems (GIS) and Planning Support Systems (PSS) technologies has provided the opportunity for planning agencies to adopt and facilitate participatory e-planning for improved decision-making. Despite this opportunity, studies show that a number of impediments to the widespread adoption these technologies exist. Drawing on the theoretical perspectives of planning, the literature on participatory planning and e-planning, as well as reviews of some existing technologies for supporting participatory planning practices, this chapter concludes that although a well designed participatory e-planning system could be an enabler for collaborative decision-making and help reduce tensions and conflicts that surround many urban development projects, the deliberative features of newer e-planning systems will have to be improved to move beyond general documented feedback, exploit the spatiality of the participatory environment, and allow more real-time dynamic consultation, if they are to be effective participatory tools.
"Potential" Barriers to E-Government Implementation in Developing Countries
Authors: Hamner Marvine , Taha Doaa , Brahimi Salah
Published: May 2010

Developing countries interested in initiating E-Government will confront a number of issues and challenges in this endeavor. These issues and challenges often manifest themselves as “potential” barriers to implementation including: the lack of infrastructure; sustainability; culture; knowledge, skills, abilities, and attitudes; and, privacy and security. However, as this article shows many of these will not be “real” barriers. This article also presents a number of solutions and recommendations for the potential barriers discussed. Furthermore, research has found that local customization of E-Government will be crucial in developing countries; and, that privacy and security issues do not appear to be as big a concern as may be thought. The intent of this article is to outline the issues and challenges (potential barriers) for E-Government implementation and discuss potential solutions to these barriers, in order to generate a dialogue to establish a solid, technological and social foundation for E-Government.
Collaborative Knowledge Construction with Web Video Conferencing
Authors: Hatzipanagos Stylianos , Basiel Anthony , Fillery-Travis Annette
Published: May 2010

This chapter explores how web-based video conferencing (WVC) can be used to create and support learning environments within a work based learning context. Computer mediated communication interactions through WVC can support collaborative knowledge construction by encouraging dialogical processes in communities of learners and practitioners. We position our field of exploration within the educational landscape defined by socio-economic changes, resulting from the development of the knowledge economy, and the explosive growth of information and communication technologies to serve it.
Challenges with Knowledge Construction in an E-learning Environment
Authors: Olaniran Bolanle A. , Olaniran Oladayo , Edgell David
Published: May 2010

Knowledge construction, or new knowledge creation, is believed to be a way to allow learners to gain an in-depth knowledge and a greater control over the materials they are learning. E-learning technology platforms, that facilitate e-collaboration among learners, represent a way to foster knowledge construction. This chapter however, explores challenges facing knowledge construction especially when looking at “Culture” and how it affects two different learning philosophies or paradigms. This chapter elucidates some of the challenges and offers a new direction for accommodating different learners’ needs.
Extending the JADE Framework for Semantic Peer-To-Peer Service Based Applications
Authors: Poggi Agostino , Tomaiuolo Michele
Published: May 2010

One of the main challenges of multi-agent systems is to become the main means to support legacy systems interoperability and to make the realization of scalable distributed systems easy. In the last years, however, two technologies, peer-to-peer and service-oriented, have made an impressive progress and seem to have good chances of competing with multi-agent systems for the realization of scalable and interoperable systems. Conversely, neither of these two technologies is able to provide by themselves the autonomy and social and proactive capabilities of agents and thus the development of flexible adaptive distributed systems may be difficult. This chapter shows how JADE, one of the most known and used software framework for the development of multi-agent systems, has been extended with these technologies both to support the realization of multi-agent systems and to facilitate the interoperability with peer-to-peer and service-oriented systems.
Adaptive Ensemble Multi-Agent Based Intrusion Detection Model
Authors: Helmy Tarek
Published: May 2010

The system that monitors the events occurring in a computer system or a network and analyzes the events for sign of intrusions is known as intrusion detection system. The performance of the intrusion detection system can be improved by combing anomaly and misuse analysis. This chapter proposes an ensemble multi-agent-based intrusion detection model. The proposed model combines anomaly, misuse, and host-based detection analysis. The agents in the proposed model use rules to check for intrusions, and adopt machine learning algorithms to recognize unknown actions, to update or create new rules automatically. Each agent in the proposed model encapsulates a specific classification technique, and gives its belief about any packet event in the network. These agents collaborate to determine the decision about any event, have the ability to generalize, and to detect novel attacks. Empirical results indicate that the proposed model is efficient, and outperforms other intrusion detection models.
Mobile Web Services for P2P Computing
Authors: Aijaz Fahad
Published: May 2010

The Information Technology (IT) and Telecommunication (TelCo) sectors face enormous integration challenges, due to the prominent heterogeneity in existing systems. Service-oriented computing tackles such challenges by providing a fundamental platform that facilitates the convergence of distinct domains based on Web Services (WSs). With the mobility and technological advancements, service-oriented computing has been pushed towards the mobile sector enabling P2P Mobile Web Services (MobWSs) provisioning. In this work, we investigate the interaction, architecture and design characteristics of MobWSs for P2P computing. Here, the two MobWS interaction strategies are presented followed by the architectural discussion, enfolding server and client side components, of a resource-oriented MobWS framework. We follow REST design principles to propose an efficient way of architecting P2P MobWS systems, as an alternative to SOAP, enabling significant payload reduction and performance optimization in mobile servers. The detailed performance evaluation is also presented and compared to SOAP based on real-time measurements. By analyzing performance characteristics, we show that REST is a promising technique to architect P2P MobWS systems for resource-constraint mobile nodes.
Master And Slave Transluminal Endoscopic Robot (MASTER) for Natural Orifice Transluminal Endoscopic Surgery (NOTES)
Authors: Phee Soo Jay , Low Soon Chiang , Yang Kai , Kencana Andy Prima , Huynh Van An , Sun Zhenglong , Lomanto Davide , Ho Khek-Yu
Published: May 2010

In this chapter, authors try to explain and develop a robot for medical application. Some robot is already working with doctor and some is under improvement stage.  Master and Slave Transluminal Endoscopic Robot (MASTER) with 9 degree of freedom (DOF) end effectors which are long and flexible so as to enhance endoscopic procedures and notes.
ECG Data Analysis
Authors: Pal Saurabh , Majumder Swanirbhar
Published: May 2010

In this chapter authors explain an idea for automation of heart failure with the help of ECG signals. An electrocardiogram (ECG) is a test that records the electrical activity of the heart. A brief description on automatic classification techniques is also given. ECG being the most vital physiological signal, its acquisition technique, noise and artifacts elimination methodologies are discussed in this chapter.
Venom and ECG Signal Processing
Authors: Maheshwari Ranjan , Kumar Vinod , Verma H. K.
Published: May 2010

In this chapter authors try to explain types of poison and where and when it used by the animals. The basic purpose of venom is to defend self by immobilizing the opponent, be it a predator or a prey. The nature has blessed many animals with venom.  Snakes and spiders house venom in their mouth and scorpions keep it in their tail whereas, honeybees, wasps and other insects have developed special stingers for venom delivery.
Applications of Robots in Surgery
Authors: Najarian Siamak , Afshari Elnaz
Published: May 2010

In this chapter authors explain an application robotics in the field of medical diagnosis as well as in different medical fields such as rehabilitation, surgery, various diagnostic stages, medical and surgical training, etc.  They discuss simply omnipresent surgery or MIS and robotic surgery and introduce different robotic surgery systems and technologies in the world.   They talk about surgery and different methods of it using a chronological approach.
The Evolution of Hermite Transform in Biomedical Applications
Authors: Gopalakrishnan Raghavan , Mugler Dale H.
Published: May 2010

In this chapter authors proposed an new techniques for conversion from continuous signal and images to digital form. This chapter is also try to explain a new method of generating a discrete version of the continuous Hermite functions to biomedical signals and images that are digital.    The process is computationally simple, and provides a set of vectors that share many of the properties of the continuous Hermite functions that are otherwise lost in the discretization process.
Using Ontologies in eHealth and Biomedicine
Authors: Alexandru Adriana , Filip Florin Gheorghe , Galatescu Alexandra , Jitaru Elena
Published: May 2010

The goal of the chapter is to enhancement the medical system performance and provides a overview of available healthcare system. It is also provide a idea for simulation of different results, activities, systems, groups, institutions, theories, the benefits ontologies bring to the e-Health and biomedicine domains and the effort already given in this respect. This system is seen as an application of ontologies in the occupational health domain and representation and integration of the semantic and modeling layers of a system based on ontologies for the prevention of occupational risks.
Examining Tensions in Telework Policies
Authors: Gibbs Jennifer L. , Scott Craig R. , Kim Young Hoon , Lee Sun Kyong
Published: May 2010

This chapter examines workplace policies related to virtual work, with a specific focus on telework policies. Such policies are important to successful telework in communicating rules and expectations and providing a basis for negotiation between individual teleworkers and their employers. A content analysis of 35 state government telework policies revealed that such policies are characterized by two major tensions between autonomy and control and between flexibility and rigidity. The first tension relates to issues such as individual versus organizational responsibility for monitoring performance, providing equipment, and ensuring physical and data security, while the second tension relates to the standardization of working hours and eligibility criteria, whether rules are clear or left ambiguous, and the degree of work/family balance. Although explicit contradictions between stated benefits and realities of telework implementation may be problematic, most of the policies used tension productively by providing enough ambiguity to allow for competing individual and organizational interests to co-exist. Practical implications for teleworkers and their managers are suggested.
Efficiency
Authors: Möller Andreas
Published: May 2010

Recently, there has been increasing recognition that computer-based information systems should better support corporate sustainability management. New administrative approaches, e.g. in the field of emission trading, and recommendations, for instance regarding carbon footprints of products, require a new type of information systems in companies. These new components can be called corporate environmental management information systems (CEMIS). What is the purpose of these systems? They should provide the required information for environmental or sustainability management. But what is the idea behind? What is the guiding principle of these systems? This chapter discusses efficiency as a guiding principle of CEMIS. It helps to understand better basic methodologies like life cycle assessment, and it provides presuppositional knowledge for the challenge of introducing these information instruments.
Additional Challenges for CEMIS Due to Impacts Caused by Climate Change
Authors: Antoni-Komar Irene , Beermann Marina , Schattke Hedda
Published: May 2010

The aim of this paper is to evaluate how CEMIS could be enhanced to cope with impacts caused by climate change. In our time, firms have to deal with the resulting challenges such as increasing complexity and dynamics of the environment. By developing cultural competences, firms will be empowered to handle these new challenges appropriately. CEMIS itself as a managerial tool has an excellent potential to increase organizational resilience against vulnerabilities due to impacts caused by climate change. CEMIS could provide climate change scenarios for different impacts in global and regional dimensions. Scenarios as alternative images of how the future might unfold are an appropriate tool to analyze how driving forces may influence future emission outcomes and to assess the associated uncertainties and risks. They assist in climate change analysis, including climate modeling and the assessment of impacts, adaptation and mitigation. Theoretical enlargements of the CEMIS concept will be discussed by resilience thinking, which is promising for CEMIS because of its turning away from the equilibrium assumption, its widespread comprehension of the environment and its influences, its assumption of flexibility and adaptiveness through the adaptive capacity. The discussion will be exemplified by firms from the food industry, which are highly vulnerable towards direct and also indirect impacts caused by climate change along certain supply chains. Changing qualities and quantities of resources, temporary shortage of resources or conflicts between energy and food can all have drastic effects on firms in the food industry. Supported by CEMIS as a critical information system, emerging conflicts due to changing societal and cultural processes can be recognized sensitively, reflected critically, and reconfigured creatively to the aim of sustainable strategic management. Based on the theory of social practice and the competence theory of the firm, the development of cultural competences, as an integral part of the practical intelligibility of firms and as a learning concept for adaptive capacity, enables firms to handle these new challenges in times of expanding uncertainty and risk appropriately.
Enterprise Architecture Applied Towards Sustainable IT Governance
Authors: Ramos Karoll Haussler Carneiro , Molinaro Luis Fernando Ramos , Rocha Adson Silva , Maranhão Ana Carolina Kalume , Elias de Deus Flávio
Published: May 2010

Evidence shows that investments made in the IT (Information Technology) area have a positive effect on organizational performance, even if these benefits are difficult to measure and associated with the real intention of those investments. IT presents itself as a tool and not as a guarantee of success, as this determining factor depends on how it is used and directed towards strategic alignment. This chapter sought to evaluate how much IT governance positively interferes in the achievement of strategic goals, based on the control of investments and its correct management. The results show that the organizations which adopt IT governance have their performance highly improved in relation to other companies, especially concerning profitability. Besides, the use of enterprise architecture in IT governance shows a positive correlation with corporative governance elements, encouraging the use of more efficient management mechanisms to promote sustainable IT.
A Framework for the Implementation of Eco-Efficient Business Systems
Authors: Shakir Maha
Published: May 2010

Environmental sustainability is an important issue for many individuals, businesses, and governments nowadays. One of the road blocks to sustainable practice is cost, which is an important consideration, particularly for business. The eco-efficiency movement was initiated to address this concern. This chapter reviews the eco-efficiency concept and explains why it is becoming a current issue for many organizations today. The chapter further aims to understand eco-efficient implementation strategies and methods, and the important role that information systems play in creating the required organizational capabilities for these implementations. A framework of eco-efficiency implementation is developed through mapping eco-efficiency strategies to different implementation methods. The framework illustrates how each method is suitable for a particular eco-efficiency strategy. With the understanding that information systems form an integral part of most eco-efficiency implementations, the role of information systems in creating eco-efficiency capabilities is highlighted to enrich the framework.
Management Instruments for Sustainable Information Systems Management
Authors: Erek Koray , Schmidt Nils-Holger , Zarnekow Rüdiger , Kolbe Lutz M.
Published: May 2010

The increasing dissemination of information systems (IS) into all areas of business and personal life has drawn attention to its economic, environmental and social effects. IS organizations are becoming aware that they have to take up their responsibility by thinking seriously about sustainability management for information systems. While measures for using computing resources efficiently have received considerable attention, the topic of sustainability in IS management is still lacking theoretical and conceptual foundation. As a contribution to the ongoing discussion of “Green IT”, the purpose of this chapter is to apply the concept of sustainability into the field of IS management using practical concepts such as a procedural model, the balanced scorecard and a maturity model.
Development of an Information System for the Assessment of different Bioenergy Concepts Regarding Sustainable Development
Authors: Schmehl Meike , Eigner-Thiel Swantje , Ibendorf Jens , Hesse Martina , Geldermann Jutta
Published: May 2010

From an environmental, economic, social, and technical perspective, this chapter focuses on a sustainability assessment of concepts for the energetic use of biomass in order to provide decision support for different options of biomass use. In rural areas, bioenergy concepts are of particular interest in this context. These can for example be biogas plants which are operated by electric service providers, or a biogas plant owned by one farmer, or bioenergy villages. The topic relates to the development of suitable criteria and to the adaption of existing indicator systems to the special requirements of sustainable biomass use for energy. The results of this sustainability assessment consider the different biomass concepts’ advantages and disadvantages, which are illustrated by multi-criteria valuation methods. Furthermore, the sustainability assessment of bioenergy concepts has specific requirements with regard to an information system in terms of data and information’s demand and supply side.
Sustainable Scorecard as an Actionable Framework for Managing Sustainability
Authors: Pozzebon Marlei , Arroyo Paulina , Fleury Angela
Published: May 2010

This paper investigates how corporate sustainable practices can be supported by information management models and information and communication technology (ICT) applications. The empirical work is based on a single case study, a Brazilian company that is applying the concept of a sustainability balanced scorecard (SBSC) to put forward a triple bottom-line strategy. Our results suggest that (a) implementation and use of the SBSC, (b) integration of the triple-bottom line concept within the SBSC, and (c) the place occupied by the eco-efficiency indicator at the heart of the strategic map represented three key factors that helped to enhance sustainability management. Moreover, the development of a sustainability-oriented culture and the strong business intelligence (BI) platform put in place enabled successful implementation of the SBSC in this particular company.
Understanding Transformative Learning in Online Education
Authors: Yuzer T. Volkan , Kurubacak Gulsun
Published: May 2010

In these days when innovation and creativity have become crucial in online education programs and courses, higher education institutions should consider about the judgments of authorities about these novel activities, opinions of program development staff, and comparisons executed programs with its online education design. Therefore, the main purpose of this chapter is to discuss about how to develop and deliver transformative online education surrounded by egalitarian values of excellence in each stage of this action, and also global qualities which are vital in higher education. To integrate diverse and multicultural principles under any online education model in higher education, online learning should focus on the development, implementation and evaluation steps of its distance education system, and help all stakeholders decide whether they continue or terminate their online education.
Constructing Transformative Learning Communities in 3D Immersive Learning Environments
Authors: Howard Barbara , Sanders Robert , McClannon Terry
Published: May 2010

Programs that prepare leaders for the 21st century must do so with the intent of equipping them not only with traditional reserves of knowledge and theory but with a focus on application of the knowledge base to build the skills necessary for collaborative leadership resulting in a community of practice. School leaders must be prepared to transform their existing school culture by challenging current paradigms and fundamental principles of how schools have operated traditionally in an era when teachers were responsible primarily for the transference of discreet sets of knowledge with little or no emphasis on higher level thinking skills, group work, and informational literacy. Without this transformative shift, school leaders tend to fail in successfully implementing reform efforts geared toward developing schools ready to meet the challenges of the information age. This chapter will discuss how faculty in the department of Leadership and Educational Studies at Appalachian State University have utilized Presence Pedagogy to engage their students in tranformative learning for school leadership through cross-program collaboration in a 3D immersive learning environment.
Breakthroughs, Breakdowns, and Some Productive Pedagogical Paradoxes of Virtual Learning
Authors: Miller Vachel , Clark-Keefe Kelly
Published: May 2010

Learning sites in higher education have become more diffuse, diverse, and tangled. As instructors, we can hybridize our encounters with students, meeting them one week in class; another week, in virtual space. Our initial experimentation with hybrid learning has left us face-to-face with breakthroughs, break-downs, and deep pedagogical dillemmas. In this chapter, we voice our emergent sensibilities about the transformative potential—both for our students and ourselves—of inhabiting a hybrid learning environment. Our discussion is based on our observations of doctoral students’ interaction and engagement on-line, as well as our own embodied sensitivities about how we, as instructors, experience ourselves and our work in the pedagogical movement between our classrooms and virtual space.
Socio-Cultural Dimensions of E-Learning Systems
Authors: Adeoye Blessing Foluso , Oni Adesoji
Published: May 2010

As students develop critical and reflective thinking skills and are encouraged to care about the world around them, they may realize that some degrees of personal or social transformations are required. Considering this, it is important to note that transformational process can be enhanced with online learning (especially e-learning). Therefore, knowledge about the relationship between culture and online education is very relevant. The purpose of this study was to explore the relationship between national culture and the usability of an e-learning system. Hofstede’s cultural dimensions were used to guide the cultural aspects of this study while Nielsen’s four usability attributes were also used to support the usability aspect of the study. It was concluded that individual cultural backgrounds contribute substantially to the usability of most online learning systems. Teachers and designers can talk about crafting or designing the learner experience, but the level of control over learner experience is quite indirect and mediated by several factors not under teacher control. With respect to transformative learning, some learners may be ready for deeper change while others are not.
Teaching Transformative Learning and Digital/Online Education
Authors: Goulah Jason
Published: May 2010

This chapter focuses on transformative learning and digital literacies/online education in the context of second and foreign language teacher preparation. Building upon research begun in Village Voices, Global Visions: Digital Video as a Transformative Foreign Language Learning Tool (Goulah, 2007b), this chapter describes a graduate bilingual-bicultural education seminar coupling transformative learning theory and digital literacies for pre- and in-service teachers in Chicago, Illinois, in the United States. The author examines how transformative learning and digital literacies/online education can be applied to language education and considers specific theory-to-practice means for teachers of culturally and linguistically diverse students to conceptualize, critique and resist planetary trends and meet the needs of English language learners across the curriculum through digital literacies.
Spatial distributions of zooplankton during coastal upwelling in western Lake Superior
Authors: Megard R. O. , Kuns M. M. , Whiteside M. C. , Downing J. A.
Published: May 2010

Zooplankton distributions during coastal upwelling in western Lake Superior were mapped with a high‐frequency (192‐kHz) sonar system that consists of an echosounder and a navigation receiver connected to a microcomputer. An acoustic transect after a September storm revealed a sloping sound‐scattering layer, traceable more than 5 km offshore, in the thermocline between an upwelling water mass and a returning front of surface water. Interfacial shear produced short internal waves on the scattering layer, and regularly spaced plumes of high backscattering in the surface layer were attributed to stream lines of eddies that were transporting sound scatterers from aggregations in the thermocline to the lake surface. The sloping sound‐scattering layer was due to high concentrations (up to 105 ind. m−3) of copepods, chiefly Leptodiaptomus sicilis. Backscattered sound (volume‐scattering strength) was highly correlated with concentrations of microcrustacea in samples collected with nets, consistent with Rayleigh scattering theory for ideal elastic spheres the size of adult L. sicilis (target strength = −123 dB).

Acoustic sampling revealed a skewed frequency distribution; low animal concentrations (<1,000 m−3) occupied most (65%) of the zooplankton space, but a small proportion (<10%) of the space contained very dense aggregations (> 105 m−3) with concentrations several orders of magnitude larger than the median. Infrequent patches of very high densities are probably a general feature of zooplankton populations, because the patchiness inferred from sound backscattering is similar statistically to distribution patterns in lakes and oceans sampled with conventional methods. The densest aggregations are likely to be the most important for foraging fishes but are so infrequent they are unlikely to be detected with conventional sampling methods.
Regulation and role of photosynthesis in the colonial symbiotic ciliate Ophrydium versatile
Authors: Sand‐Jensen Kaj , Pedersen Ole , Geertz‐Hansen Ole
Published: May 2010

Symbiotic photosynthesis of the colonial ciliate Ophrydium versatile from transparent temperate lakes was studied with O2 microelectrodes and measurements of O2 and C exchange in laboratory and field incubations. Oxygen gradients were steep just above the colony surface and shallow toward the center of the colony, reflecting that O2 metabolism is high in the peripheral layer containing the ciliates and low in the jelly. Photosynthesis responses resembled those of unicellular and thin multicellular algae by having relatively low light compensation point (25 µmol photon m−2 s−1), low light saturation point (190 µmol photon m−2 s−1), and a sharp transition from light‐limited to light‐saturated photosynthesis. Inorganic C supply to Ophrydium supported photosynthetic rates close to maximum in air‐saturated alkaline lake water. Photosynthesis patterns were similar in short‐time laboratory experiments and diel outdoor experiments and showed no indication of photoinhibition and rhythmicity in the relationship of photosynthesis to irradiance during the day. The endosymbiotic zoochlorellae dominated the O2 metabolism of Ophrydium ciliates, resulting in much steeper O2 gradients at the colony surface in the light than in the dark and a large diel surplus of gross photosynthesis relative to respiration. Symbiotic photosynthesis produced sufficient carbon to support the measured growth rate, the respiration, and the substantial carbon content of the colony jelly, whereas particle filtration of ciliates presumably supplied the nutrients for net growth of the assemblage. The location of the ciliates at low density in the periphery of the colony and the water movements generated by the ciliates are probably important for the efficient plant‐like use of light and inorganic C by Ophrydium and the ability to form high densities of zoochlorellae.
The effect of nitrogren limitation on the absorption and scattering properties of the marine diatom Thalassiosira pseudonana
Authors: Reynolds Rick A. , Stramski Dariusz , Kiefer Dale A.
Published: May 2010

Optical properties of the marine diatom Thalassiosira pseudonana were examined in nitrate‐limited semicontinuous cultures for growth rates (µN) varying from 0.22 to 1.32 d−1. Two experiments were conducted at each growth rate in which sampling of the culture was done at either the dark‐to‐light (D‐L) or light‐to‐dark (L‐D) transition of a 12‐h photoperiod. Optical cross sections and efficiency factors for absorption, scattering, and attenuation were calculated from measurements of the spectral absorption and beam attenuation coefficients, cell concentration, and the size distribution of cells in suspension. The refractive index of cells, relative to seawater, was calculated from these data using an inverse method. Nitrogen limitation strongly influences the optical properties of this species. Absorption cross sections increased more than twofold with increasing µN, predominantly caused by increases in the imaginary part of the refractive index, n′. At the red absorption peak, n′(673) increased 140% and was strongly correlated with intracellular Chl a concentration. For most visible light wavelengths, scattering cross sections were not a strong function of growth rate but were consistently largest in the L‐D transition experiments. The difference between D‐L and L‐D experiments at any given µN increased with increasing growth rate; for example, scattering cross sections at 660 nm in the L‐D experiments were 25% (µN = 0.22 d−1) and 90% (µN = 1.32 d−1) larger than in the respective D‐L experiments. The real part of the refractive index at λ = 660 nm varied from 1.024 to 1.039 among all experiments and was positively correlated with intracellular carbon concentration. The Chl a‐specific absorption coefficient decreased with increasing µN (e.g. 43% decrease in the blue Soret band) in response to decreases in the carotenoid‐to‐Chl a ratio and increased pigment packaging. The Chl a‐specific scattering coefficient at 660 nm decreased from 0.55 to 0.09 m2 (mg Chl a)−1 with increases in µN. Our results suggest that the optical properties of phytoplankton populations in nitrogen‐limited surface waters may be significantly altered from those in deeper portions of the water column.
Drastic changes in deep‐sea sediment porewater composition induced by episodic input of organic matter
Authors: Gehlen Marion , Rabouille Christophe , Ezat Ullah , Guidi‐Guilvard Laurence D.
Published: May 2010

We report the first seasonal time‐series observations of porewater composition obtained for deep‐sea sediments. We observed considerable temporal variability of O2, NO3−, and Mn2+ profiles at the French JGOFS site DYFAMED (western Mediterranean) in response to a pulsed input of organic matter. A delivery of reactive organic matter representing only 1% of the average organic C content of surface sediments (0.6% wt/wt) was required in order to fuel the observed changes in porewater composition. The perturbation resulted in dramatic changes in integrated reaction rates and sediment‐water fluxes. O2 uptake rates increased from 1.26 to 1.82 mmol m−2 d−1, while nitrification rates rose from 0.13 to 0.18 mmol m−2 d−1. These changes were paralleled by a decrease in NO3− effluxes across the sediment‐water interface from 0.07 to 0.01 mmol m−2 d and a concomitant rise of denitrification rates from 0.06 to 0.17 mmol m−2 d−1. Porewater profiles responded rapidly to the sediment pulse deposition, returning to their steady‐state values within a few months. The main driving force appeared not to be the seasonal variability of pelagic production but rather the downslope transport of resuspended upper‐shelf sediments.
UVB radiation and depth interaction during primary succession of marine diatom assemblages of Greece
Authors: Santas Regas , Lianou Charalumbia , Danielidis Daniel
Published: May 2010

Exposure to UVB radiation caused shifts in the species composition of diatom assemblages developing on ceramic tiles in a natural marine habitat near Korinthos, Greece. These differences in community structure were more pronounced during the first month of community development. The diatom species Mastogloia crucicula and Nitzschia constricta were sensitive to both UVA and UVB radiation, while Amphora delicatissima, Amphora veneta, Opephora olsenii, Synedra baccilaris, and Synedra robusta were excluded by exposure to UVB but not to UVA. Amphora robusta, Cocconeis fluminensis, Mastogloia erythraea, and Mastogloia ovalis were absent from 0.5 m while Nitzschia bilobata was present only in 1.0 m. Mastogloia badjikiana, Mastogloia labuensis, Nitzschia lanceolata, and Synedra laevigata were present during different stages of succession. The fact that differences in community structure do not persist at later successional stages suggests that periphytic communities of the upper euphotic zone possess adjustment mechanisms to the stress posed by increased solar ultraviolet radiation.
Observations of a deep aggregation of Calanus pacificus in the Santa Barbara Basin
Authors: Osgood Kenric E. , Checkley David M.
Published: May 2010

An optical plankton counter/CTD package was used with zooplankton net samples to map the distribution of fifth copepodid (C5) Calanus pacificus in the Santa Barbara Basin region during two autumn cruises. Diapausing C5 C. pacificus were aggregated in a layer just above the basin’s oxygen‐deficient bottom waters and below its sill depth. The maximal concentration measured was 6,900 ind. m from a net sample spanning a depth range double the thickness of the C5 layer. Although the C5 concentration varied, the layer was found at all stations of sufficient bottom depth within the basin. During November 1994, C5 C. pacificus accounted for 95–97% of all zooplankton caught in net samples from the layer. Relatively low concentrations of deep‐dwelling C5 C. pacificus were observed at nearby stations outside the basin. We hypothesize that C5 C. pacificus descend into the Santa Barbara Basin at diapause, are trapped, and accumulate in a region of relatively low predator abundance. The resultant aggregation is estimated to contain a significant fraction of the regional C. pacificus population and thus assumes an important role in its dynamics.
The origin of sedimenting detrital matter in a coastal system
Authors: Lundsgaard Claus , Olesen Michael
Published: May 2010

Total sedimentation and the fraction due to copepod fecal pellets were measured during the growth season (March–October 1989) in the southern Kattegat, Denmark. In this period the sedimentation of detritus made up 52 g C m−2, equal to 82% of the sedimenting matter from the euphotic zone, but fecal pellets (11 g C m−2) constituted only a minor fraction. The remaining detrital matter was produced by other heterotrophs than copepods. Published data on heterotrophic biomass and grazing obtained during the investigation in the Kattegat are reviewed in order to relate the sedimentation to processes in the pelagic system. Copepod defecation nearly equaled the sedimentation of fecal pellets, indicating that retention of this matter in the pelagic system was insignificant. A considerable fraction (10–24%) of the carbon flow processed by heterotrophic pico‐, nano‐, and microplankton was converted to detritus that was lost from the mixed system by sedimentation. The microbial food web is thus not an exclusively regenerating system.
Gymnodinium breve red tide blooms: Initiation, transport, and consequences of surface circulation
Authors: Tester Patricia A. , Steidinger Karen A.
Published: May 2010

From its source waters in the Gulf of Mexico the red tide dinoflagellate, Gymnodinium breve is moved throughout its oceanic range by major currents and eddy systems. The continental shelf off the west coast of Florida experiences frequent G. breve blooms (in 21 of the last 22 years) where the spatially explicit phases of G. breve blooms are closely coupled to physical processes. Bloom initiation occurs offshore and in association with shoreward movements of the Loop Current or spinoff eddies. A midshelf front maintained by seasonal wind reversals along the Florida west coast may serve as a growth and accumulation region for G. breve blooms and contribute to the reinoculation of nearshore waters. Local eddy circulation in the northeastern Gulf of Mexico and in the Dry Tortugas affects the retention and coastal distribution of blooms while the Florida Current and Gulf Stream transport cells out of the Gulf of Mexico and into the U.S. South Atlantic Bight. The causes of bloom dissipation are not well known but mixing or disruption of the water mass supporting G. breve cells, especially in combination with declining water temperatures, are important factors.
Harmful algal blooms and red tide problems on the U.S. west coast
Authors: Horner Rita A. , Garrison David L. , Plumley F. Gerald
Published: May 2010

On the U.S. west coast, the main toxin‐producing algal species are dinoflagellates in the genus Alexandrium that cause paralytic shellfish poisoning (PSP) and diatoms in the genus Pseudo‐nitzschia that produce domoic acid and cause domoic acid poisoning (DAP). Other harmful species, including the raphidophyte Heterosigma akashiwo and the diatoms Chaetoceros convolutus and Chaetoceros concavicornis, kill fish at aquaculture sites, but are not harmful to humans. Water discolorations (red tides) caused by nontoxic dinoflagellates also occur throughout the area. Early records, partially based on local native lore, suggest that algal toxins have been present along this coast for hundreds of years, but actual scientific information is sparse. We review what is now known about harmful algal blooms in this vast area, including the hydrographic regimes that induce and(or) support blooms, bloom dynamics, and the biology of the causative species.
Harmful algal blooms: Their ecophysiology and general relevance to phytoplankton blooms in the sea
Authors: Smayda Theodore J.
Published: May 2010

From 60 to 80 species of phytoplankton have been reported to be harmful; of these, 90% are flagellates, notably dinoflagellates. The effects of turbulence on harmful algal bloom (HAB) taxa, their photoadaptive strategies, growth rate, and nutrient uptake affinity (Ks) are considered. Flagellates, including HAB taxa, collectively have a lower nutrient uptake affinity than diatoms. Four major adaptations are suggested to have been evolved to offset the ecological disadvantages of their low nutrient affinity: nutrient retrieval migrations; mixotrophic tendencies; alle‐lelochemically enhanced interspecific competition; and allelopathic, antipredation defense mechanisms. Motility‐based behavioral features of flagellates contributing to their blooms include: phototaxis, vertical migration, pattern swimming, and aggregation, which facilitate nutrient retrieval, trace metal detoxification, antipredation, depth‐keeping, and turbulence avoidance. Neither a general physiological syndrome nor distinctive physiological profile distinguishes harmful flagellate species from nonharmful taxa. However, HAB flagellates exhibit significant ecophysiological differences when compared to diatoms, including greater biophysical vulnerability to turbulence, greater bloom dependence on water‐mass stratification, greater nutritional diversity involving mixotrophic tendencies, greater potential use of allelochemical mechanisms in interspecific competition and antipredation defenses, and unique behaviorial consequences of their motility. Flagellates use a “swim” strategy; diatoms a “sink” strategy.