Nucleic acid synthesis in oceanic microplankton from the drake passage,antarctica: Evaluation of steady-state growth

Differential uptake of [³H]adenine and [³H]thymidine, and incorporation of tritium label into proteins, RNA and DNA as a function of depth, indicate that surface microplankton incorporated most of the assimilated radioisotopes into nucleic acids. Growth processes for deep-sea microplankton were shifted towards higher rates of [³H]-adenine incorporation into RNA compared to rates of thymidine incorporation into DNA. Deep-sea microplankton also diverted a larger portion (up to 80%) of the assimilated tritium into biosynthetic pathways for amino acid and eventual incorporation into proteins. These results imply that protein synthesis is vital for deep-sea microplankton where populations may be stressed by low levels of available nutrients. The rates at which microplankton incorporated [³H]adenine into RNA and DNA, and [³H]thymidine into DNA, suggest that oceanic microplankton are in a transient state of balanced growth, i.e. between two steady-state growth conditions, irrespective of potential growth rates. Our results support the hypothesis that oceanic microplankton are in various growth states.     

Further Development of a Specific Conductivity Approach to Measure Groundwater Discharge Area within Lakes

Groundwater exchanges with most lakes are rarely quantified because there are many technical challenges to quantification. We investigated a lakebed mapping approach to infer the relative areas of groundwater exchange in 12 prairie shallow lakes and five Laurentian mixed forest shallow lakes in Minnesota, USA in 2011. We used a relatively common approach (seepage meters) to provide baseline information on the magnitude and direction of flow at four locations in each lake. To expand from point measurements to the whole‐lake scale, we explored use of specific conductivity as a cheaper and more time efficient proxy for groundwater discharge to lakes. We validated the approach at near shore stations in each lake where seepage meter measurements and specific conductivity surveys overlapped. Specific conductivity surveys provided a similar assessment of groundwater discharge compared to seepage meters for 50% of the lake‐sampling period combinations. The lakebed mapping approach, when validated for a lake with a limited number of seepage meter (or alternative methods) measurements, offers the advantages of being more time and labor efficient over the use of a similar number of seepage meter monitoring locations; seepage meters (or piezometers, for example) are costlier in terms of equipment and labor, even for single‐lake studies. We show the combined approach could provide useful baselines for understanding and mapping groundwater exchange in shallow lakes.     

Public parks as an element of urban planning: a missing piece in Accra's growth and development

Public parks are important to urban environments, residents, and visitors. Among other functions, they provide environmental services, such as air and water purification, and they increase both recreational opportunities and the attractiveness of the urban environment. Because of their importance, urban parks serve as public spaces that provide visitors and urban residents with rights to the city. This paper identifies the dearth of urban public parks in Accra-Tema city-region as worrying. The Accra Plan 1958 underscored the significance of green spaces and designated the coastal strip for parks development but the areas have been lost to various urban uses. We argue that the continual neglect of public parks within urban planning and community development schemes in the Accra-Tema city-region is a major concern because it is depriving the citizens a right to the city and its public spaces. A number of factors have worked adversely against the provision of public parks and green spaces in the city-region. These include development pressures, undue political interference, a complex land delivery system, and ad hoc planning. The paper concludes by offering policy suggestions as to how to resolve the dearth of parks and green spaces in the city-region.     

In situ remediation of PCE at a site with clayey lithology and a significant smear zone

Groundwater at the former Serry's Dry Cleaning site in Corvallis, Oregon, was impacted by chlorinated volatile organic compounds (CVOCs). The primary CVOCs impacting the site include tetrachloroethene, trichloroethene, dichloroethene, and vinyl chloride, which were detected at concentrations up to 22,000, 1,700, 3,100, and 7 μg/L, respectively, prior to treatment. Large seasonal fluctuations in groundwater CVOC concentrations indicated that a significant fraction of the CVOC mass was present in the smear zone. Field‐scale pilot tests were performed for the Oregon Department of Environmental Quality's Dry Cleaner Program to evaluate the performance of EHC® in situ chemical reduction (ISCR) technology. The pilot study involved evaluating field performance and physical distribution into low‐permeability soil using basic Geoprobe® injection tooling. The testing results confirmed that bioremediation enhanced by ISCR supported long‐term treatment at the site. This article describes the implementation and results of the tests. Performance data are available from a three‐year period following the injections, allowing for a discussion about sustained performance and reagent longevity. © 2010 Wiley Periodicals, Inc.     

Do Catch-and-Release Guidelines from State and Provincial Fisheries Agencies in North America Conform to Scientifically Based Best Practices?

Many recreational anglers practice catch-and-release angling, where fish are returned to the water with the presumption that they will survive. However, not all fish survive, and those that do often experience sublethal consequences including injury and stress. There is compelling scientific evidence that angler behavior and gear choice can affect the success of catch-and-release as a management and conservation strategy. Because anglers often look to government natural resource agencies for guidance on how to handle and release fish properly, there is a need to assess whether their outreach materials are readily accessible and provide the necessary and correct information on the subject. Therefore, on-line catch-and-release guidelines developed by state and provincial natural resource agencies across North America were evaluated to determine whether their guidelines were consistent with the best available scientific information. This analysis revealed that there was immense variation in the depth and breadth of coverage among jurisdictions. Agency guidelines contradicted one another in several areas including air exposure, angling in deep water, venting trapped gases, and resuscitation. In many cases, the guidelines failed to provide sufficient direction to actually be of use to anglers or provide direction consistent with contemporary scientific literature. This analysis will assist with developing outreach materials that promote sustainable recreational fisheries and in maintaining the welfare status of individual fish.     

Can public engagement democratize environmental policymaking in a resource-dependent state? Comparative case studies from Alberta,Canada

What factors shape the democratic potential of public consultation in environmental policymaking? Here, the motivations, purposes, designs, and outcomes of recent public engagement on land use planning, climate change policy, and water resource management in Alberta, Canada are reviewed in order to show how the power dynamics of the political and economic context shape the democratic potential of public and stakeholder consultations, especially where dominant resource interests are at stake. At the same time, political leadership, interactions between civil society actors and key design elements are shown to be important to democratization.     

DISTRIBUTION AND STOCHASTIC GENERATION OF ANNUAL AND MONTHLY PRECIPITATION ON A MOUNTAINOUS WATERSHED IN SOUTHWEST IDAHO1

ABSTRACT: The 18-year precipitation record from the dense gage network on the Reynolds Creek Experimental Watershed located in southwest Idaho was used to determine the spatial distribution of annual and monthly precipitation on a mountainous watershed. Analyses of these data showed a linear relationship between annual amounts and elevation. This relationship was best when the gages were grouped into downwind and upwind sites. This grouping was appropriate because most of the winter storms moved over the watershed from the west and southwest, and the heaviest precipitation was on the west (downwind) side of the watershed. Gage sites along the western and southern watershed borders were most representative of the upwind gages on the east side, because they measured the precipitation from the air moving upwind onto the watershed. The maximum annual precipitation on the watershed was just leeward of the western watershed boundary. The monthly precipitation and elevation relationship was also best represented by grouping the gage sites into upwind and downwind sites. However, during the summer when there are only small amounts of pre cipitation and thunderstorms are the source of most precipitation, one equation can be used to represent the elevation relationship. This study also showed that the log-normal distribution could be used to generate the annual synthetic series, and the cube-root-normal distribution could be used to generate monthly synthetic series for all locations on the watershed.     

Global sustainability: Toward measurement

The widespread interest in the concept of sustainable environment and development has been accompanied by the need to develop useful systems of measurement. We discuss the use of indicators which might be used to assess such conditions. Our characteristics, or criteria, for desirable global sustainability indicators are:

sensitivity to change in time

sensitivity to change across space or within groups

predictive ability

availability of reference or threshold values

ability to measure reversibility or controllability

appropriate data transformation

integrative ability

relative ease of collection and use

We discuss the basis of these characteristics, and examine two categories of indicators (soil erosion and population) and two specific indicators (physical quality of life index and energy imports as a percentage of consumption) for their value as sustainability measures.     

Uptake of heavy metals by some edible vegetables irrigated using wastewater: a preliminary study in Accra, Ghana

The heavy metals (Fe, Zn, Pb, Ni, Cr, Co, and Cd) burden in wastewater, soil, and vegetable samples from a wastewater irrigated farm located at KorleBu, Accra has been investigated. Flame atomic absorption spectrometry after microwave digestion using a combination of HNO₃, HCl, and H₂O₂ (for water), and HNO₃ and HCl (for soil and vegetables). The mean concentrations (in milligrams per kilogram) of heavy metals in the soil samples were in the order of Fe (171?±?5.22)?>?Zn (36.06?±?4.54)?>?Pb (33.35?±?35.62)?>?Ni (6.31?±?8.15)?>?Cr (3.40?±?3.63)?>?Co (1.36?±?0.31)?>?Cd (0.43?±?0.24), while the vegetables were in the order of Fe (183.11?±?161.2)?>?Zn (5.38?±?3.50)?>?Ni (3.52?±?1.27)?>?Pb (2.49?±?1.81)?>?Cr (1.46?±?0.51)?>?Co (0.66?±?0.25)?>?Cd (0.36?±?0.15). The bioconcentration factors suggest environmental monitoring for the heavy metals as follows: Cd (0.828), Cr (0.431), Ni (0.558), Co (0.485), and Fe (1.067). Estimated daily intakes were very low for both children and adults except Fe (0.767 mg/kg/day) in children. The population that consume vegetables from the study area were, however, estimated to be safe based on the results obtained from the health risk index, which were all?<?<1. The sodium absorption ratio according to FAO (1985) classifications indicate that the wastewater in the study area is unsuitable for irrigation purposes.