bluuebunny/crossref_metadata_2025 huggingface dataset:
Engaging Citizens Through Local e-Government
Authors: Shackleton Peter
Published: May 2010

The early moves to e-Government in Australia were prompted by factors such as government reform, the need to reduce costs and the desire to improve the effectiveness of service delivery. Often these were the objectives of higher levels of government rather than individual councils in the local government sector. While there have been significant improvements in many areas of local e-Government, a number of local councils in Australia particularly those in rural communities are yet to have enhanced their web-based services. The chapter will report on the progress local government in Australia have made towards e-Government implementation, specifically on citizen access to electronic service delivery. The chapter provides a background to the types of electronic information and services provided by local government in Australia and recent moves in Australia to enhance citizen involvement. The research identifies many of the internal and external pressures on local government which are often different from those at higher levels of government. At the local government level, where a significant number of citizen-to-government transactions occur in Australia, e-Government can be as much a barrier as it can be an enabler for citizen access to information and services. The result for local government is often a varied and at times confused approach to e-Government.
Community Policing in India
Authors: Arlikatti Sudha , Wachira David , Gregory Sarah
Published: May 2010

‘Community policing’, a major reform in policing, broadens the police mandate beyond the traditional focus of fighting crime to addressing community problems through a personalized approach that draws citizens into the process of policing themselves. Emulating this movement, the Police Administration in numerous states of India have recently engaged in community policing through e-governance specifically tailored to meet the diverse needs of their populace. Two such case studies, eCOPS in Andhra Pradesh and Lokvani in Uttar Pradesh are discussed showing the multifold benefits of such a movement in increasing transparency, trustworthiness, and efficiency of the police administration. The chapter concludes by making a bid to foster this symbiotic digital mode of interaction between the police and citizens by introducing domain specific performance measures. Such measures will allow for easy monitoring, revising, and garnering national support to institutionalize, validate, standardize, facilitate, and promote these programs to help create a proactive all-hazards resilient citizenry for the future.
Deliberation, Participation, and "Pockets" of E-Democracy
Authors: Romano Michael K.
Published: May 2010

Over the past few decades, researchers have attempted to unravel the puzzle of whether or not democracy exists online. According to recent evaluations (Norris, 2001; Hindman, 2009), while we find that the ‘Net may have the potential to help spread democracy through its open-endeddiscussions and mass appeal, it has deteriorated into an elite-level discourse due to what is commonly referred to as the “Long Tail” effect (Anderson, 2006) by researchers. This chapter reevaluates the popular theories of democracy online and calls into question the relevance of the question “does digital democracy exist?” Instead, I propose that digital democracy should be evaluated in terms of the sustainability of democratic tendencies within a given site, rather than its mere existence. I argue that scholars have jumped to the conclusion that the potential for democracy online has withered because they have focused too heavily on how a few key websites function to control the majority of traffic on the Web, and have not looked deeper into the infrastructure that is built within these websites and others to evaluate whether or not at a micro-level these sites act and public forums for the open deliberation of ideas and common questions. Instead of viewing democracy through a democratic lens based on liberal proceduralism, we should think of digital democracy existing in “pockets” – self-contained, community-based, democracy based on small, semi-autonomous, group dynamics.
A Review of City Portals
Authors: Deakin Mark
Published: May 2010

This chapter reviews the development of portals by cities, their digital technologies and socially-inclusive platforms and sets out a simple four-phase model of e-government to describe their on-going transformation. It goes on to discuss e-government’s recent transition from stage three to four, some of the post-transactional issues underlying their democratization of service provision and the participation of citizens in the consultations and deliberations this transformational process supports.
Virtual Neighborhoods and E-Government
Authors: Moody Rebecca , de Kool Dennis , Bekkers Victor
Published: May 2010

In this chapter the potential of GIS oriented neighborhood websites in the Netherlands will be researched. This new way of location based e-government will be analyzed by conducting four case studies in which neighborhood websites hold a central position. Relevant questions include to what degree these websites improve service delivery on the side of the government and to what degree the position of citizens is strengthened and whether they are pleased with the website and with the results. Attention will be paid to critical factors for success when designing the website but also while implementing the website and when the website is running. This will be done in terms of service delivery, closing of the gap between government and citizens and the strength of the position of citizens. Finally, we will answer the question on how GIS oriented neighborhood websites can be implemented so they have the highest potential by citizen satisfaction.
Computer Support in E-Collaborative Learning-By-Doing Environments
Authors: Qiu Lin
Published: May 2010

With the recent widespread use of computer and web technologies, web-based tools have been developed to mediate collaboration and facilitate knowledge construction. However, how to effectively design these tools to stimulate and maintain productive knowledge construction remains a challenge. This chapter describes a virtual learning-by-doing environment where students take the role of consultants to investigate the cause of recurring pipe corrosion in a paper processing company. We illustrate how the learning environment is designed to provide both pedagogical and technological support to collaborative knowledge construction. Our goal is to provide an example and offer guidance to professionals and educators who are interested building such virtual environments.
Hunting Drugs for Potent Antigens in the Silicon Valley
Authors: Runthala Ashish
Published: May 2010

In this chapter author’s represent an idea for development of a model for epitope.  It is also explains the immunological aspects and algorithms applied for epitope selection, with their practical problems.  Current techniques used to model the native state conformation of epitopes are then described with their fundamental problems.  So, the algorithms to validate such models are discussed.  Techniques to screen effective potent drugs against the target epitopes are then considered.
Online Teaching as Virtual Work in the New (Political) Economy
Authors: Schwartzman Roy , Carlone David
Published: May 2010

Online teaching and learning has been adopted throughout higher education with minimal critical attention to the challenges it poses to traditional definitions of academic labor. This chapter explores four areas where the nature of academic labor becomes contestable through the introduction of online instruction: (1) the boundaries demarcating work from personal time; (2) the relative invisibility of online labor; (3) the documentation, recognition, and rewards attendant to online instruction; and (4) the illusory empowerment of online students as consumers. The theory and practice of what constitutes “legitimate” labor in higher education require substantial reconsideration to incorporate the online dimension.
The Ethical Implications of the Virtual Work Environment
Authors: Byers Rachel N.
Published: May 2010

Ethical issues due to the following four major factors inherent to virtual work are examined: (1) organizational culture, (2) trust, (3) cross-cultural diversity, and (4) monitoring. The author proposes that the negative ethical implications of the virtual work environment can be overcome by following the suggested steps and proposed guidelines. Areas for potential future research are included and are followed by an overall discussion of the issues covered and some closing remarks.
The Electronic Panopticon
Authors: Long Shawn D. , Goodman Richie A. , Clow Chase
Published: May 2010

This chapter explores the role of surveillance in virtual work. With the modern societal shift as well as the increased global market, working virtually is becoming more necessary and even a requirement at times. With the removal of physical interaction, questions of how to properly ensure productivity arise. This chapter suggests the panopticon, as developed by Bentham (1791) and expounded upon by Foucault (1977), is very influential in the surveillance of virtual activity. This chapter will ultimately explore theoretical underpinnings of the panopticon, work place surveillance, virtual surveillance in practice, ethical issues created by virtual surveillance, and consequences of virtual surveillance.
Status and Influence Processes in Virtual Teams and Mobile Collaborations
Authors: Ravlin Elizabeth C.
Published: May 2010

Communication between members of decision-making teams has long been known to be strongly influenced by member status. However, we still know relatively little about how status and status-driven influence processes change with the implementation of technologically-mediated virtual teams and mobile collaborative enterprises. Early predictions were that technologically-mediated communication would essentially flatten the status hierarchy of groups and teams (Kiesler, Siegel, & McGuire, 1984), allowing all members, regardless of position, social identity, or other characteristics, to have equal access to the decision-making process. A review of relevant theoretical approaches and prior empirical findings indicates that in all likelihood, status processes and influence are maintained in these settings, at least in some cases to the detriment of team effectiveness. This chapter examines, through the manifestations and functions of interpersonal status, the effects of technological mechanisms of collaboration on communication processes, relationships, and practices.
Innovation and Sustainable Development
Authors: von Hauff Michael , Jörg Andrea
Published: May 2010

Many economic roundtables have proclaimed innovation as the key to economic growth. The theoretical basis for this view is amply demonstrated by today’s modern innovation theory. However, the fact that innovation also carries ecologic risk was, until recently, largely ignored. The potential for ecologic risk occurs when technologies are developed that threaten environmental damage that perhaps, does not become significant until well into the future. Risk may also occur indirectly when new technologies generate higher productivity but are also responsible for an additional burden on the environment. In principle, within the context of the sustainable development paradigm, innovation must be compatible with the three dimensions: Ecology, Economy and Society. The aim of this paper is to discuss the deficits of the mainstream innovation theory in the context of sustainability in addition to the role and significance of innovation in environmental engineering. This especially includes the opportunities and limitations of eco-innovation with respect to the current environmental policies for sustainable economic growth. A future challenge for research from a business perspective is to align eco-innovation as an integral component of an environmental management information system (CEMIS). In this context, eco-innovation can make a major contribution to environmental protection. However, within the scope of this paper, the focus is primarily on the rationale for sustainable innovation, in particular, eco-innovation.
How can Information Technology be Adopted by Micro-Enterprises
Authors: Kamal Mehruz , Qureshi Sajda , Wolcott Peter
Published: May 2010

The growth of micro-enterprises is a key driver of economic development. The ability of micro-enterprises to adopt IT can potentially increase their growth by 3.4% according to a World Bank expert. However these gains do not always take place as the challenges are many. Current theoretical models on IT adoption focus on the intent to adopt IT in large organizations where employees’ attitudes and perceptions are measured in terms of their objectives within the structures of accountability. Micro-enterprises are unique in that the intention to adopt is an individual decision made by the micro-entrepreneur. It is often the innovative ways in which IT is used that enable the gains to be realized by micro-entrepreneurs. This chapter describes a process that can be used to enable micro-entrepreneurs faced with limited resources to adopt IT to grow their businesses. This process of IT therapy involves diagnosis, interventions and an assessment of IT for development outcomes. Examples and guidelines are provided to enable this process to be used by practitioners. This chapter concludes with alternatives for sustainable development and guidelines for achieving these improvements in micro-enterprises.
Investigation of Environmental Monitoring Designs for Corporate Management Information Systems
Authors: Erechtchoukova Marina G. , Chen Stephen Y. , Khaiter Peter A.
Published: May 2010

The evaluation of an organization’s environmental performance is an integral part of a corporate environmental management information system. This chapter considers an organization’s environmental impact assessment with respect to a water resource. It investigates formal approaches to the development of temporal monitoring designs for producing data sufficient to perform the assessment. In this study, simple random sampling, stratified random sampling, and designs obtained using greedy search have been investigated with respect to their compatibility with a corporate environmental management information system. All three approaches determine temporal monitoring designs with minimal costs and supply data sufficient for estimation of water quality indicators for a given level of uncertainty. It is shown that monitoring designs obtained using the greedy search approach will outperform other designs when the level of uncertainty in the estimate must be low. If high levels of uncertainty are tolerable, simple random designs become preferable due to their simplicity and effectiveness. The proposed approaches lead to automated procedures which can be easily integrated into a corporate environmental management information system.
Corporate Environmental Management Information Systems Influence of Green IT on IT Management and IT Controlling
Authors: Gadatsch Andreas
Published: May 2010

Green IT (Green IS, Green ICT) is a concept of saving energy consumption to reduce IT costs. A current survey shows that only few companies in German speaking countries consider this aspect in their daily business. This is important facing the current situation of attempts of cost saving during the current economic crisis worldwide. This paper introduces into Green IT and presents an IT management and controlling concept. Then the main results of a currently presented survey are used to modify the concept. Finally an agenda for future research is given.
Efficient Information Provision for Environmental and Sustainability Reporting
Authors: Akkaya Cigdem , Wolf Petra , Krcmar Helmut
Published: May 2010

Environmental concerns have become a key issue for society as well as for individuals and businesses. To cope up with the pressure imposed by their various stakeholders increasingly demanding for “green” production, enterprises are constrained to balance their goals of economic growth, environmental protection and usage of natural resources. Environmental reporting provides a comprehensive and structured approach to inform the target groups about the proper environmental strategies and to present a transparent profile. Recent studies show that environmental reporting is spreading rapidly. To enable consistency and comparability, several organizations provide guidelines, standards and recommendations to guide organizations in their environmental management. Environmental reporting is mainly used by organizations as a medium to demonstrate compliance with applicable national and European level environmental regulations. In the last decades, they are also increasingly being used as a tool to communicate environmental matters to various stakeholders. The purpose of this chapter is to deliver fundamentals of environmental reporting based on a comprehensive literature review and a recent project in Germany. Moreover, the authors suggest two approaches to support data gathering and report generation processes for environmental reporting purposes of organizations.
Effective Stakeholder Relations
Authors: Arndt Hans-Knud , Graubitz Henner
Published: May 2010

Compared to the DIN EN ISO Standard 14001 every organization has to create – in respect to environmental aspects and environmental system – processes so that internal communications between different organization levels and function, or proper questions and answer coming from outer site could be guaranteed. One of the possibilities to realize these requirements is the introduction of an organization wide GRI-guideline, created by the idea of the Global Reporting Initiative (GRI), which can easily be published in the Internet. But normally not all environmental information is necessary for everybody, resulting in an information flood. Following the idea to represent special information to special interest groups we present an idea of how to convert these sustainability reports into a Topic Maps by using eXtensible Business Reporting Language (XBRL).
A Tale of Two Courses
Authors: Shaw Melanie , Bracke John , Walters Kelley , Long David
Published: May 2010

In this case study, the researchers detail the transformation of a traditional, face-to-face, graduate-level seminary course into an online offering. The course, Biblical Studies 1: Torah and Former Prophets, part of the core curriculum at a Midwestern seminary, was adapted into a distance learning course. The first group of students enrolled in the online course for the spring 2009 term. Previously, the course was offered to first-year seminarians enrolled in traditional, face-to-face, degree and non-degree programs. This was the first course offered online at the graduate institution. This study provides a description of the process of adaption of the course to a distance learning option, and contains an analysis of student assessment outcomes for assignments required in both course formats. From the analysis of student outcomes, recommendations for future instructional practice are made.
Meta Communication Concept and Knowledge Building Process in Distance Education
Authors: Demiray Ugur
Published: May 2010

“Meta Communication” is the process between message designers when they are talking about the learning process, as distinguished from their articulation of the “substantive” learning, itself. To understand knowledge building it is essential to distinguish learning—“the process through which the cultural capital of a society is made available to successive generations” from knowledge building—the deliberate effort to increase the cultural capital. These include collaborative learning, guided discovery, project-based learning, communities of learners, communities of practice, and anchored instruction. Communicative encounters between groups and individuals from different cultures are variously described as cross-cultural, intercultural, multicultural or even transcultural. Researchers use terms such as the Internet, WWW, VLE, CMC, ICTs, HCI, CHI or CSCW in explorations of technologies at the communicative interface. This chapter examines and focuses on some issues and questions relating to how the use of meta communication concept should be functional and influences for knowledge building process in Distance education.
How Online Tasks Promote Teachers' Expertise within the Technological Pedagogical Content Knowledge (TPACK)
Authors: Klieger Aviva , Oster-Levinz Anat
Published: May 2010

In the Information Communication Technology (ICT) era, teachers will have to wisely use the online environment in order to realize a new pedagogy. We developed a digital indicator for examining the extent to which technological knowledge is integrated with pedagogical content knowledge (TPACK). This indicator is used to examine online tasks developed by teachers in different subjects over time. The factors found to contribute and promote such integration are the instruction given to the teachers and time. These two factors enable the teachers to implement the appropriate pedagogy in a diverse technological environment. The authors recommend that correct integration of TPACK should be emphasized when planning professional development for teachers in the field of online tasks.
Promoting High-Order Thinking in Online Discussions
Authors: Scott Anne
Published: May 2010

Asynchronous online discussions potentially maximise the learning opportunities in tertiary education. In this chapter the design, implementation and evaluation of online discussions for developing high-order thinking skills with large groups enrolled in a preservice teacher education program are discussed. The development and evaluation of a tool indicates it is possible to examine the intellectual quality of online discussions and considering these written responses in terms of awareness, regulation and evaluation provides the facilitator with useful insights about students’ thinking. A framework for auditing the activities facilitating the online discussions for potential learning opportunities is also recommended. Findings indicate that preservice teachers do engage in productive professional discourse which transform their learning when appropriate activities are used.
Applicability of Transformative Learning Theory in E-Health Teaching
Authors: Edirippulige Sisira , Marasinghe Rohana
Published: May 2010

The use of information and communication technologies (ICT) in health/medical practices is widely known as e-Health. Evidence suggests that the use of e-Health offers new opportunities for effective clinical practices, time and cost savings for patients, doctors and health services. However, the lack of appropriate education and training opportunities is considered to be a main barrier to provide necessary knowledge and skills in e-Health. Practice of e-Health demands rethink of the existing frames of reference and the adoption of new frames of reference in health and medical practice. Resistance to such change is an obvious challenge. Carefully designed education programs are the key to address this challenge. This chapter shares the experience of adopting key tenets of transformative learning theory in designing, developing and delivering e-Health teaching at the University of Queensland Centre for Online Health in Australia.
Osteoporosis Syndrome in Thalassaemia Major: An Overview
Authors: Toumba Meropi , Skordis Nicos
Published: May 2010

Osteoporosis in thalassaemia major (TM) represents a prominent cause of morbidity. The mechanism of pathogenesis of bone disease (BD) in TM is multifactorial and complicated. Peak bone mass is achieved shortly after completion of puberty and normally remains stable until the third decade of life when age-related bone mass begins. Growth hormone (GH) and sex steroids play a crucial role in bone remodeling and in the maintenance of skeletal architecture during adult life. GH and insulin growth factors (IGFs) have anabolic effect in bone formation. Sex steroids act probably by increasing the expression of RANKL by osteoblastic cells and alterations in the RANK/RANKL/OPG system in favor of osteoclasts. Impaired GH secretion and lack of sex steroids in thalassemic patients due to pituitary damage, contribute to failure of achieving optimal peak bone mass. Other endocrine complications such as hypoparathyroidism and vitamin D deficiency have also a detrimental role on bones in TM. It is still questionable whether the international criteria for defining osteopenia and osteoporosis are relevant to patients with TM; also a question arises for the diagnostic methods such as DEXA scan and management of osteoporosis with known treatment protocols, in the thalassaemic patient.
Interannual changes in seagrass (Posidonia oceanica) growth and environmental change in the Spanish Mediterranean littoral zone
Authors: Marbà Núria , Duarte Carlos M.
Published: May 2010

The interannual changes in leaf formation and vertical growth rates and their correlation to the records available of environmental change (rainfall, mean sea level, water temperature, and transparency) were examined in 15 Posidonia oceanica meadows growing along the Spanish Mediterranean coast between 1967 and 1992. P. oceanica leaf production fluctuated interannually, but it did not exhibit any steady trend toward decline, indicative of nonhuman effects on changes in water quality in these areas. Conversely, the steady decline in vertical rhizome growth rate of P. oceanica observed in two sites suggests that shoreline erosion there could derive from human activities. In all meadows examined, interannual variability in vertical rhizome growth of P. oceanica showed clear oscillating trends, suggesting alternating episodes of sediment erosion and accretion every 7 yr and at least every 25 yr. Mean sea level and surface water temperature have been increasing for the last two decades, but water transparency has been declining. However, overall trends only accounted for 24–37% of the long‐term climatic variance. Rainfall interannual changes were dominated by time scales of 8 and 28 yr, whereas water transparency, temperature, and sea level showed dominant time scales in the oscillations of 4 and 15 yr, 6 and 20 yr, and 11 and 27 yr, respectively. In addition, 33% of P. oceanica vertical growth variability in the southern Spanish Mediterranean coast derived from variability in rainfall, suggesting a rise of erosive coastal conditions during rainy years. The similarity in the interannual changes of seagrass growth over a wide spatial scale (1,000 km), together with the significant coupling between seagrass growth and climate variability, points out climate change, and not widespread deterioration derived from anthropogenic pressure, as the main source of the observed changes in the Mediterranean littoral zone.
Phylogenetic diversity of marine coastal picoplankton 16S rRNA genes cloned from the continental shelf off Cape Hatteras, North Carolina
Authors: Rappé Michael S. , Kemp Paul F. , Giovannoni Stephen J.
Published: May 2010

The phylogenetic diversity of a continental‐shelf picoplankton community was examined by analyzing 16S ribosomal RNA (rRNA) genes amplified from environmental DNA with bacterial‐specific primers and the polymerase chain reaction (PCR). Picoplankton populations collected from the pycnocline (10 m) over the eastern continental shelf of the United States near Cape Hatteras, North Carolina, served as the source of bulk nucleic acids used in this study. A large proportion of the 169 rDNA clones recovered (33%) were related to plastid 16S rRNA genes, including plastids from both chromophyte and chlorophyte algae. Most bacterial gene clones (75% of bacterial clones, 50% of the total) were closely related to rRNA gene lineages that had been discovered previously in clone libraries from open‐ocean marine habitats, including the SAR86 cluster (γ‐Proteobacteria), SAR83, SAR11, and SAR116 clusters (all α‐Proteobaeteria), as well as the marine Gram‐positive cluster (high G+C Gram‐positive). Most of the remaining bacterial clones recovered were phylogenetically related to the γ and β subclasses of the Proteobacteria, including an rDNA lineage within the type 1 methylotroph clade of the β subclass. The abundance of plastid rDNAs and the lack of cyanobacterial‐related clones, as well as the presence of β‐Proteobacteria, are features of this coastal picoplankton gene clone library that distinguish it from similar studies of oligotrophic open‐ocean sites. Overall, however, these data indicate that a limited number of as yet uncultured bacterioplankton lineages, related to those previously observed in the open ocean, can account for most cells in this coastal marine bacterioplankton assemblage.
Processes of deep‐water renewal in Lake Baikal
Authors: Hohmann R. , Kipfer R. , Peeters F. , Piepke G. , Imboden D. M. , Shimaraev M. N.
Published: May 2010

Deep‐water renewal in Lake Baikal (Siberia), the world’s deepest lake and largest lake by volume, is relatively fast. Water age calculated from tritium and helium as well as from chlorofluorocarbons does not exceed 19 yr. Relative saturation of dissolved oxygen typically exceeds 80%. The equation of state of Baikal water was determined including the effect of dissolved ions and silicic acid. Based on nearly 600 CTD profiles taken between 1993 and 1995, two mechanisms of deep‐water mixing were identified. (1) In spring, cold and relatively saline water from the Selenga, the major inflow to the lake, forms a density plume that reaches the bottom of the central basin during April and early May. Due to entrainment of lake water the plume transports about 125 km3 of water per year to the deepest part of the basin. Later in spring, the river water forms the thermal bar observed along the eastern shore. There are indications that parts of the Selenga are also plunging to the deep part of the southern basin. (2) At Academician Ridge, separating the cold and “saline” water of the central basin from the warmer and slightly less saline water of the northern basin, horizontal mixing results in a water mass that can sink on either side of the sill. Whereas in the central basin the water mass stays at intermediate depth, in the northern basin it sinks to the deepest part. More detailed data are needed to quantify this density flux. No indication of a wind‐induced thermobaric instability was found.
Chemical defenses of the tropical, benthic marine cyanobacterium Hormothamnion enteromorphoides: Diverse consumers and synergisms
Authors: Pennings Steven C. , Pablo Sonia R. , Paul Valerie J.
Published: May 2010

The tropical, benthic marine cyanobacterium Hormothamnion enteromorphoides periodically dominates shallow reef habitats, forming erect tufts similar in size to the thalli of macroalgae. Although periodically very common and lacking structural defenses, H. enteromorphoides seems to be a low preference food item for marine herbivores. An organic extract of H. enteromorphoides deterred feeding by a natural assemblage of reef fishes, suggesting that H. enteromorphoides was chemically defended. Bioassay‐guided fractionation of the organic extract led to a mixture of related cyclic peptides, with the known compound laxaphycin A as the major component. The peptide mixture significantly and strongly deterred feeding at natural concentrations by the parrotfish Scarus schlegeli, the sea urchin Diadema savignyi, and the crabs Leptodius spp., but had a less striking and nonsignificant effect on feeding by the pufferfish Canthigaster solandri. Previous studies found that laxaphycins exhibited synergistic antifungal and cytotoxic effects. However, when tested at equal concentrations in feeding assays with S. schlegeli and C. solandri, laxaphycin A was as effective at deterring feeding as was the peptide mixture, indicating that the peptides do not interact synergistically to deter herbivory.
Role of ultraviolet‐B radiation on photochemical and microbial oxygen consumption in a humic‐rich shallow lake
Authors: Reitner Bettina , Herndl Gerhard J. , Herzig Alois
Published: May 2010

In a humic‐rich, shallow lake (Lake Neusiedl), the seasonal dynamics of the humic and the nonhumic dissolved organic carbon (DOC) were investigated and the photochemical oxygen consumption rates of these DOC fractions exposed to surface solar radiation levels were compared with that of the bulk DOC and bacterial respiration. Furthermore, bacterial utilization of the humic, nonhumic, and bulk DOC pre‐exposed to solar radiation was compared with utilization of the different fractions of DOC held in the dark prior to inoculating natural bacterial assemblages. The concentration of the unfractionated DOC pool ranged from ∼3 mmol C liter−1 during summer to 1.3 mmol C liter−1 in late spring. The mean contribution of humic DOC was 35.2% of bulk DOC. Under the full spectrum of solar radiation, photochemical oxygen consumption of the unfractionated DOC was 3.3 µmol O2 liter−1 h−1, 1.8 µmol O2 liter−1 h−1 of the humic DOC, and 1.7 µmol O2 liter−1 h−1 of the nonhumic DOC. In the absence of UVB, photochemical oxygen consumption was reduced by 35% in the unfractionated DOC, 38% in the humic, and 27.5% in the nonhumic DOC. Under the full spectrum of solar radiation, the photochemical oxygen consumption normalized to DOC was more than twice as high (2.83 µmol O2 mmol−1 C h−1) for humic than for nonhumic DOC. The bacterial oxygen consumption rate was ∼30% of the photochemical oxygen consumption of the unfractionated DOC. In batch culture experiments with natural bacterial assemblages as inocula, the bacterial yield was generally higher with substrate exposed to the full spectrum of solar radiation than with substrate held in the dark prior to inoculation. Exposure of 0.8‐µm filtered water to the full spectrum of surface solar radiation for 2–3 h resulted in a decline in activity (measured by thymidine incorporation) to 47% of the activity measured in the dark. If UVB was excluded, bacterial activity was 62% of that in the dark. Subsequent incubation at 5–20‐cm depth under in situ radiation for another 2–3 h resulted in bacterial activity similar to that detected in the dark incubations at the surface. Bacteria exposed to the full range of solar radiation at the surface and incubated subsequently in the dark exhibited significantly lower activity than bacteria exposed to in situ solar radiation in distinct depth layers. This result indicates that bacteria rapidly recover from previous UV stress in the absence of UVB. Based on our results, we estimate that the photooxidation‐mediated residence times in the top 5‐cm layer of the water column are 90 and 45.5 d for the nonhumic and humic fractions and 75 d for unfractionated DOC. For the entire water column, ∼10% of the remineralization activity (bacterial respiration + photochemical oxygen consumption) is due to photooxidation of the DOC, and the mean residence time of DOC is ∼80 d.
Vertical migration and feeding behavior of Calanus pacificus females during a phytoplankton bloom in Dabob Bay, U.S
Authors: Dagg Michael J. , Frost Bruce W. , Newton Jan A.
Published: May 2010

The abundance, vertical distribution, and feeding of Calanus pacificus females were measured at frequent intervals over 24 h during a March phytoplankton bloom in a temperate fjord. Copepod guts contained high levels of phytoplankton pigment only during the nighttime when copepods were in the upper 50 m. Feeding, however, was not strictly a function of phytoplankton availability because copepods fed equally well in the 25–50‐m layer where chlorophyll concentrations were 0.5–3 mg m−3 and there was no phytoplankton production, and in the 0–25‐m layer where chlorophyll concentrations reached 5–10 mg m−3 and all phytoplankton production occurred. In five of six nighttime sampling cycles, >50% of the copepod population resided in the 25–50‐m layer. Fifty‐eight percent of the total phytoplankton ingestion occurred in the 25–50‐m layer and was therefore derived from sinking algae. We conclude that a large fraction of the population of C. pacificus females was not migrating up to the surface layer because there was sufficient phytoplankton in subeuphotic zone waters to support high feeding rates. Although the early morning descent and the daytime depth of dielly migrating C. pacificus may be determined by risk from visually orienting predators, it appears that the nocturnal vertical distribution is modified by food availability.
Pfiesteria piscicida and other Pfiesreria‐like dinoflagellates: Behavior, impacts, and environmental controls
Authors: Burkholder JoAnn M. , Glasgow Howard B.
Published: May 2010

Toxic Pfiesteria‐like dinoflagellates have been implicated as causative agents of major fish kills (affecting 103– 109 fish) in estuaries and coastal waters of the mid‐Atlantic and southeastern U.S. Transformations among an array of flagellated, amoeboid, and encysted stages in the complex life cycle of the representative species, Pfiesteria piscicida, are controlled by the availability of fresh secretions, blood, or other tissues of fish prey. P. piscicida also is a voracious predator on other estuarine microorganisms. Pfiesteria‐like dinoflagellates require an unidentified substance(s) commonly found in fresh fish excreta‐secreta to initiate toxin production. P. piscicida is lethal to fish at low cell densities (>250–300 cells ml−1), and at sublethal levels (∼100–250 cells m1−1) it has been shown to cause ulcerative fish diseases. P. piscicida also has been linked to serious human health impacts. This dinoflagellate is eurythermal and euryhaline, with optima for toxic activity by the most lethal stage (toxic zoospores, TZs) at ≥26°C and 15 psu, respectively. Thus far it has shown no light optimum and is capable of killing fish at any time during a 24‐h cycle. In warmer waters (≥ 15°C) flagellated stages predominate while fish are dying, whereas amoebae predominate in colder conditions and when fish are dead. Nutritional stimuli influencing P. piscicida are complex; inorganic phosphate apparently can directly stimulate TZs, whereas inorganic phosphate and nitrate indirectly promote increased production of nontoxic zoospores (NTZs, maintained in the absence of live fish, as potential precursors to lethal TZs) by stimulating their algal prey. Organic phosphate (Po) and nitrogen are taken up by P. piscicida osmotrophically, and Po is stimulatory to both TZs and NTZs. The available data point to a critical need to characterize the chronic and acute impacts of toxic Pfiesteria‐like dinoflagellates on fish and other targeted prey in estuarine and coastal waters that are adversely affected by cultural eutrophication.
Macroalgal blooms in shallow estuaries: Controls and ecophysiological and ecosystem consequences
Authors: Valiela Ivan , McClelland James , Hauxwell Jennifer , Behr Peter J. , Hersh Douglas , Foreman Kenneth
Published: May 2010

Macroalgal blooms are produced by nutrient enrichment of estuaries in which the sea floor lies within the photic zone. We review features of macroalgal blooms pointed out in recent literature and summarize work done in the Waquoit Bay Land Margin Ecosystems Research project which suggests that nutrient loads, water residence times, presence of fringing salt marshes, and grazing affect macroalgal blooms.

Increases in nitrogen supply raise macroalgal N uptake rates, N contents of tissues, photosynthesis‐irradiance curves and Pmax and accelerate growth of fronds. The resulting increase in macroalgal biomass is the macroalgal bloom, which can displace other estuarine producers. Fringing marshes and brief water residence impair the intensity of macroalgal blooms. Grazing pressure may control blooms of palatable macroalgae, but only at lower N loading rates. Macroalgal blooms end when growth of the phytoplankton attenuates irradiation reaching the bottom. In estuaries with brief water residence times, phytoplankton may not have enough time to grow and shade macrophytes. High phytoplankton division rates achieved at high nutrient concentrations may compensate for the brief time to divide before cells are transported out of the estuary.

Increased N loads and associated macroalgal blooms pervasively and fundamentally alter estuarine ecosystems. Macroalgae intercept nutrients regenerated from sediments and thus uncouple biogeochemical sedimentary cycles from those in the water column. Macroalgae take up so much N that water quality seems high even where N loads are high. Macroalgal C moves more readily through microbial and consumer food webs than C derived from seagrasses that were replaced by macroalgae. Macroalgae dominate O2 profiles of the water columns of shallow estuaries and thus alter the biogeochemistry of the sediments. More frequent hypoxia and habitat changes associated with macroalgal blooms also changes the abundance of benthic fauna in affected estuaries.

Approaches to remediation of the many pervasive effects of macroalgal blooms need to include interception of nutrients at their watershed sources and perhaps removal by harvest of macroalgae or by increased flushing. Although we have much knowledge of macroalgal dynamics, all such management initiatives will require additional information.
Toward a theory of biological‐physical control of harmful algal bloom dynamics and impacts
Authors: Donaghay Percy L. , Osborn Thomas R.
Published: May 2010

A growing body of laboratory, field, and theoretical work suggests that the dynamics of harmful algal blooms and their impacts on other organisms are frequently controlled not only by physiological responses to local environmental conditions as modified by trophic interactions, but also by a series of interactions between biological and physical processes occurring over an extremely broad range of temporal and spatial scales. All too frequently, major gaps in our ability to identify, measure, and model the underlying biological and physical processes and their interactions over the appropriate temporal and spatial scales have prevented the quantitative assessment of the importance of these factors in causing past blooms and the development of predictive models of bloom dynamics and impacts. For these reasons, we have combined fluid continuity equations with a conservation equation for population dynamics to quantify how biological and physical processes and their interactions affect the population dynamics of harmful algae and their potential impact on other organisms. Applications of the resulting numerical and conceptual models to toxic algal blooms in upwelling systems and pycnocline layers suggest not only that bloom dynamics and impacts are sensitive to biological‐physical interactions occurring at multiple scales, but also that such interactions may be critical components of the life‐history strategies of these organisms.
Spatial patterns in dense algal blooms
Authors: Franks Peter J. S.
Published: May 2010

Intricate and striking patterns are often created in dense algal blooms by the interaction of sinking, floating, or swimming algae and local physical dynamics. The structure of these patterns can reveal a great deal about the processes underlying the pattern formation. Here I explore three common patterns in dense algal blooms: chaotic mixing, internal wave banding, and sharp fronts. For each of these patterns, I develop a simple model to simulate the qualitative aspects of the patterns. The models are then analyzed to better understand the time and space‐dependent processes involved in pattern formation and to suggest ways in which we might better sample such patterns to more accurately quantify the dynamics. One significant result of this analysis is that complicated patterns of Lagrangian tracers need not be driven by similarly complicated patterns of the flow.
Interaction of photochemical and microbial processes in the degradation of refractory dissolved organic matter from a coastal marine environment
Authors: Miller William L. , Moran Mary Ann
Published: May 2010

The interaction between photochemical and biological processes in the degradation of marine dissolved organic matter (DOM) was investigated with seawater from a coastal southeastern U.S. salt marsh. Seawater supplemented with humic substances was exposed to alternating cycles of sunlight (equivalent to 8 h of midday sun) and dark incubations with natural bacterial populations (1–2 weeks in length). Photochemical degradation of the DOM was monitored during sunlight exposure by direct measurements of dissolved inorganic carbon (DIC) and carbon monoxide (CO) formation in 0.2‐µm filtered seawater. Bacterial degradation was monitored during dark incubations by tritiated leucine uptake and changes in bacterial numbers in bacterivore‐free incubations and by direct measurements of DOM loss. The alternating cycles of sunlight and microbial activity resulted in more complete degradation of bulk DOM and marine humic substances than was found for nonirradiated controls (i.e. with microbial activity alone) by a factor of up to 3‐fold. Increased decomposition was due both to direct losses of carbon gas photoproducts (DIC and CO in a 15 : 1 ratio) and to enhanced microbial degradation of photodegraded DOM, with approximately equal contributions from each pathway. Mass balance calculations indicated that low‐molecular‐weight carbon photoproducts, currently considered to be the compounds responsible for stimulating bacterial activity following photodegradation of DOM, were insufficient to account for the enhanced bacterial production observed. Thus, higher molecular weight, chemically uncharacterized fractions of DOM may also be modified to more biologically available forms during exposure to natural sunlight.
Planktonic grazers are a potentially important source of marine dissolved organic carbon
Authors: Strom Suzanne L. , Benner Ronald , Ziegler Susan , Dagg Michael J.
Published: May 2010

A series of laboratory experiments was performed to measure dissolved organic carbon (DOC) production during herbivorous grazing by heterotrophic protists (ciliate Strombidinopsis acuminatum, dinoflagellate Oxyrrhis marina) and copepods (Calanus pacificus). DOC production by phytoplankton was also measured. Experiments were performed in artificial seawater to provide a low DOC background against which changes in DOC concentration could be measured directly. We found that DOC production during grazing was high, i.e. 16–37% of algal C content was released as DOC during an ingestion event. Bacterial growth rates were stimulated by grazer activity, most likely due to increased availability of labile DOC; breakage of fecal pellets by copepods may also have yielded DOC. In contrast, DOC production by phytoplankton was low, ranging from 3 to 7% of algal C content per day. Generalizing from these rates, a simple budget shows that grazer DOC production should be 4–6 times greater than phytoplankton DOC production in any region of the ocean where grazing is the dominant phytoplankton loss process. Both phytoplankton and grazer species influenced the carbohydrate composition of the DOC produced. Dissolved carbohydrates averaged 30 and 22% of total DOC in phytoplankton‐only and grazer‐containing treatments, respectively, and most variability in carbohydrate content was due to variations in polysaccharide levels. We conclude that planktonic grazers are potentially a major source of DOC in the marine environment.