Eutrophication and the macroscope

It is important to view eutrophication as an increase in the supply of organic matter to an ecosystem rather than as a simple problem of nutrient pollution. This emphasizes that eutrophication is a fundamental change in the energetic base that may propagate through the system in various ways and produce a variety of changes. Some of these changes may be desirable (e.g., increased secondary production) and some may not (e.g., hypoxia). Defining eutrophication in terms of changing nutrient concentrations or chlorophyll levels or species composition confuses symptoms with the underlying phenomenon. While nutrient enrichment is the most common cause of eutrophication, it is not the only one. As recent and ongoing nutrient reductions make an impact in the coastal waters of the wealthier nations, we will see an increasing number of systems in which primary production is decreasing. This reduction in the supply of organic matter is here defined as oligotrophication, a phenomenon now well documented in lakes. So far, there has been little appreciation of this limnological study by coastal marine ecologists or managers, but there is much we can learn from it. The great ecologist H.T. Odum long argued that we need ‘macroscopes’ to help ecologists see the problems they study as they are embedded in the larger scales of nature and society. Marine eutrophication (and oligotrophication) is a perfect example of a problem that must be studied with a view toward the larger scales as well as toward the microscopic details. While much of the hardware (e.g., satellite imagery) for the mythical macroscope has been developed in the last 30 years, many ecologists and managers still look at eutrophication as a local problem linked to local sources of nutrient enrichment. Such a parochial view isolates eutrophication from its long intellectual history—a history that is linked to the development of our understanding of production in coastal waters. It also neglects the intellectual richness and complexity of eutrophication. One example of the importance of the macroscopic view is the emerging importance of climate-induced changes in phenology and the consequences of changing phenology on productivity. These changes may lead to eutrophication or oligotrophication. Climate changes may also exacerbate or alleviate conditions such as hypoxia that are associated with eutrophication. Seeing eutrophication in the macroscopic view is important for understanding and managing the phenomenon

Scheduled Peripheral Component Interconnect Arbiter

Systems and methods are described for arbitrating access of a communication bus. In one embodiment, a method includes performing steps on one or more processors. The steps include: receiving an access request from a device of the communication bus; evaluating a bus schedule to determine an importance of the device based on the access request; and selectively granting access of the communication bus to the device based on the importance of the device

Direct measurements of light attenuation by epiphytes on eelgrass \u3cem\u3eZostera marina\u3c/em\u3e

Declines in the seagrass Zostera marina L. in estuaries and lagoons have been attributed in part to reductions in irradiance reaching the seagrass blades. Epiphytes growing on Z. marina have the potential to attenuate a large fraction of the light that would otherwise reach the blades. This problem has previously been studied by measuring light penetration through homogenized epiphytic slurries or through glass slides fouled with epiphytes. However, the latter may not represent the natural succession or species composition found on live Z. marina leaves and the former does not preserve the structure of the epiphytic complex. Further, past studies have not measured attenuation across the full range of epiphytic densities found in the field. In this study, we measured light penetration across a wide range of epiphytic densities by holding scraped and unscraped Z. marina blades over a submerged light sensor. Results compared well with past studies at low epiphyte densities, with strong reductions in light penetration as density increased. However, at higher densities, penetration leveled off to a relatively constant value as the epiphytes floated out from the edges of the blade. Studies using slurries did not capture this phenomenon and thus predicted decreasing penetration down to 0%

Benthic community metabolism in a coastal lagoon ecosystem

Measurements of benthic oxygen production and consumption at 3 stations over an annual cycle in a shallow (mean depth = 0.7 m) coastal lagoon on the Rhode Island (USA) coast provide evidence that shallow benthic communities may consume more organic matter than can be provided by impressive rates of in situ epifloral production. While sandy sediment areas in Potter Pond lagoon showed a net daytime production of about 140 g C m-2 yr-l, the more extensive areas of fine-grained sediment did not show any significant amount of net benthic daytime production annually. Moreover when nighttime respiratory costs were included, the lagoon benthos as a whole showed a net organic consumption of 30 g C m-2 yr-l in spite of a net annual daytime production rate of 50 g C m-2 yr-l. Rates of in situ oxygen uptake by fine-grained lagoon sediments in the dark were not separable from those of similar sediments in much deeper (mean = 8.6 m) Narragansett Bay. For the lagoon as a whole, the benthos consumed about 40 to 50% of the combined primary production by phytoplankton, macrophytes and benthic epiflora. This partitioning is similar to that found in deeper, plankton-based systems with completely heterotrophic bottom communities

Nitrogen Inputs to Rhode Island Coastal Salt Ponds - Too Much of a Good Thing

Reviews concerns about increase of nitrogen in Rhode Island salt ponds as a result of human activities

Lessons Learned For Future Designs From Thermal Treatment Of Perchlorate In Soil

A soil remediation project using ex-situ thermal desorption to remove explosive compounds was modified at the latter stages of planning to include treatment of perchlorate. The design-build approach consisted of a bench scale study, which verified the treatability of perchlorate at baseline treatment conditions, and pilot scale studies, which helped refine the process parameters for full-scale treatment. During initial full-scale operations, a high number of treated soil batches failed to meet the project treatment criteria. Analytical results of samples collected from various stages along the treatment train indicated a potential for perchlorate contamination to by-pass the primary treatment process. Slower feed rates and higher operating temperatures did not show any conclusive positive impact on treatment efficiency. Recycling the particulates from the air pollution control equipment back into the feed soil was initially considered, but was deemed infeasible with the current equipment design configuration. A cost-effective solution was achieved by reducing the size of the treated soil sample batch volume, thereby reducing the amount of soil requiring re-treatment when occasional failures occurred. Future plant designs intended for treatment of perchlorate could potentially improve destruction efficiency by recycling particulates to the beginning of the process instead of the treated soil discharge

The shift in framing of food and beverage product reformulation in the United States from 1980 to 2015

AbstractFood and beverage product reformulation is a public health nutrition policy of recent prominence; it is a so-called ?win-win? policy, as unlike other nutrition policies, it has the potential to also benefit the food and beverage industry. However, reformulation has also been criticized as being driven by industry interests. In order to inform future policy debates about reformulation, we sought to investigate how and why reformulation became a public health initiative by conducting a framing analysis on 278 US newspaper articles from 1980 to 2015. Frames are aspects of text emphasizing a particular definition of a problem or solution, and they help shape policy discourses and the public policy agenda. Three primary frames of reformulation were identified: business, health, and political. Having multiple frames enables reformulation to assume different meanings in different contexts, which helps to explain how it has garnered broad support from multiple sectors. The political frame of reformulation, however, only grew in importance after 2001, to describe reformulations occurring in response to public health policy initiatives aimed at obesity and noncommunicable diseases. The increasing use of a political frame, and the events described in the articles, suggests that voluntary reformulation followed a growing threat of policy change and litigation facing the industry, a finding that provides important context to debates about voluntary reformulation initiatives. Future reformulation initiatives will need to reconcile and negotiate the varying frames and aims of reformulation in order to ensure they are a success from the public health perspective

Study of phenotypic and gene expression response to bacterial challenge

In the mouse model of Bacillus Calmette-Guérin (BCG)-induced inflammation, focus is placed upon phenotypic and gene-expression responses to the original challenge. Studies of the phenotypic response to BCG involves several behavior indicators, categorized as representing an initial period of sickness response, and a set of depression-like behaviors that can endure for several weeks. Little is known about the impact of relationships among indicators on these studies, as most analyses have treated indicators independently. Gene-expression studies have also been small in scale, limiting what is known about gene-expression during these behavioral changes. With the availability of Next-Generation Sequencing platforms, the scale of transcriptome analysis can be greatly increased. This study aims to address these previous limitations, characterizing behavioral and gene-expression responses to BCG-induced inflammation

Criteria for Evaluating Journals in the Scholarship of Teaching and Learning in Agriculture, Natural Resources, and the Life Sciences

The purpose of this paper was to identify existing criteria that may be considered in evaluating journals in the scholarship of teaching and learning in agriculture, natural resources, and the life sciences. This can assist faculty authors and evaluators of promotion and tenure cases to explain indicators of the quality of the publications. The commonly accepted criteria are: peer review; acceptance rate; longevity; open access availability; inclusion in indexing/abstracting services; citation analysis; and expert opinion. These data were collected for a representative set of journals which indicated that: acceptance rates for the journals varied widely; most of the journals existed for at least 10 years; most of the journals did not have an ISI impact factor or Eigenfactor TM Score; the ERIC database was the predominant indexing resource; and there were no published lists of journals in these subjects compiled from expert opinion

The influence of prior relationship on perceptions of stalking: A comparison of laypersons, non-specialist police officers and specialist police officers

The current research examined the influence of prior relationship on perceptions of stalking, and compared the perceptions of laypersons, nonspecialist police officers, and specialist police officers. Two studies employed experimental designs where participants were presented with one of three vignettes in which the nature of the prior relationship was manipulated so that the perpetrator and victim were portrayed as strangers, acquaintances, or ex-partners. Participants comprised 101 nonspecialist police officers and 108 laypersons in Study 1, and 49 specialist police officers and 49 nonspecialist police officers in Study 2. Findings indicate that nonspecialist police officers and laypersons shared the common misperception that stranger stalkers present a greater threat to the personal safety of their victims than acquaintance or ex-partner stalkers. Specialist police officers were less susceptible to common misperceptions and believed that intervention was more necessary. Specialist police officers also believed that the perpetrator’s behavior would cause the victim more alarm or personal distress than nonspecialist police officers