Short- and long-term outcomes of gestational diabetes and its treatment on fetal development

Globally the prevalence of gestational diabetes mellitus (GDM) is rising mainly due to the increase in maternal obesity. A number of different methods to screen for and diagnose GDM have been described although consensus on the preferred methods does not yet exist. GDM has significant short- and long-term health risks for the mother, developing fetus and the children born to mothers with GDM. Short-term risks for the fetus include macrosomia (excessive birthweight), shoulder dystocia, birth trauma, and hypoglycaemia in the immediate postpartum period. Long-term risks for offspring born to mothers with GDM include increased rates of childhood and adulthood obesity and an increased cardiometabolic risk. A number of pharmacological treatments for GDM have been identified, these include insulin and oral glucose-lowering drugs metformin and glibenclamide. Whilst these oral glucose-lowering drugs show similar short-term childhood outcomes to insulin there is increasing evidence that these drugs may have adverse long-term outcomes on children and adults exposed to the drugs in utero. Future research on treatments for GDM should include long-term follow- up of children exposed to glucose lowering medication in utero to determine the long-term cardiometabolic risk in the offspring born to mothers with GDM.     

Layers of Antarctic krill, Euphausia superba : are they just long krill swarms?

Antarctic krill, Euphausia superba Dana, a major component in the southern ocean food web, typically occur in aggregations that range from small, discrete swarms and schools through to layers and superswarms that extend horizontally for several kilometres. A large Longhurst–Hardy plankton recorder has been used to obtain high-resolution serial samples from within two layers (up to 4 km in length) that were found near Elephant Island, north of the Antarctic Peninsula. Krill length, sex and maturity stage, net and acoustic estimates of number density are shown to vary significantly within these large layers. The variation occurring within a single layer is comparable with that occurring in a set of 38 swarms sampled contemporaneously with the layers. Thus, unlike a krill swarm, a whole krill layer may account for a substantial amount of the variation in the local krill population, although individual parts of the layer cannot be considered in this way. The layers play an important role in the ecology of the krill within the area. Firstly, these large layers may contain a significant proportion of the biomass within an area. Secondly, the structure of the layers gives some insight into the ways in which krill swarm formation and dispersal may be occurring. Received: 28 March 1997 / Accepted: 3 December 1997     

A study of the oxidative degradation of polyolefins

The oxidative degradation of polyolefins in the presence of transition metal catalysts is well known in the patent and technical literature. It has been suggested that a properly designed oxidatively degradable polymer could be used in limited lifetime articles and also on those whose primary method of disposal is composting, wherein the thermal activity is used to accelerate the oxidation process. The results of a detailed study of transition metal reactivity in the presence of numerous oxidation promoting species in polyolefins are presented. The oxidative degradation of these polyolefins was demonstrated at moderate temperatures under air and in a simulated compost environment. Approaches to determining the ultimate fate of these materials are discussed.     

CHANGE IN LAKE TROPHIC STATE AND INTERNAL PHOSPHORUS RELEASE AFTER ALUMINUM SULFATE APPLICATION1

ABSTRACT: Recovery of eutrophic lakes after nutrient diversion may be delayed if the lake experiences significant internal phosphorus (p) loading to the water column. A maximum dose of aluminum sulfate, defined herein, was applied to the anaerobic sediments of the hypolimnia of two dimictic Ohio lakes following septic tank diversion, with the objective of attaining long term control of the release of phosphorus to the water column from these sediments. The results were compared to a similar, downstream, untreated lake. Total phosphorus concentration declined sharply after treatment and has remained so through 1980 for both lakes, a period of 5 and 6 years of control, respectively. Internal P loading from anaerobic, hypolimnetic sediments was partially controlled by the treatment but there are other important sources, perhaps in the littoral zone, in these lakes. Algal biomass is Smaller and water transparency has increased. Both lakes became mesotrophic after treatment, as described by the Carlson (1977) trophic state index, and remain in that improved condition to date. No deleterious side effects were observed, although one lake experienced a significant decrease in diversity of planktonic microcrustacea and a lakeward extension of the macrophyte community. This method appears to be an effective and lasting means of accelerating the recovery of a eutrophic lake following nutrient diversion.     

ENVIRONMENTAL IMPACTS OF APPLYING MANURE,FERTILIZER, AND SEWAGE BIOSOLIDS ON A DAIRY FARM1

ABSTRACT: Farms that once spread only manures are now also applying sewage biosolids (sludge) and/or other wastes such as those from food processing. The objective of this study was to monitor environmental impacts at a dairy farm applying these materials. Fields were selected representing recent waste applications of manure (M1, M2), sewage biosolids (B1, B2), or fertilizer only control (F1, F2), although most fields had historical biosolids applications. Fields representing each treatment were not experimental replicates because of varying applications and soil characteristics. Septage and food processing wastes were also applied. Soil percolates were collected with wick lysimeters. Runoff was sampled at seven stream sites. Test field soils and alfalfa (Medicago sativa) were analyzed for trace elements. Cumulative trace metal loadings were low, at most only 1 percent of USEPA Part 503 limits. Surface soil enrichment was most evident for Mo, P, and S. Alfalfa tissue showed no trends of concern. The B2 site had the greatest percolate concentrations for 6 of 13 elements. Percolate Cu was somewhat elevated at Sites M1, M2, B2, and Fl. Percolate sodium was elevated on all M and B fields and sulfur was greatest at M2, B1, and B2. Soluble orthophosphate correlated with stream discharge during intensive monitoring of Stream Sites S1 (fertilizer) and S2 (biosolids). Peaks in S2 streamwater Mo lagged large runoff events by five days. Total streamwater export of Cu, Na, Mo, and soluble P were greater from the S2 biosolids subwatershed than from the S1 fertilizer subwatershed. Percolate concentrations exceeded corresponding streamwater concentrations in most cases.     

Household susceptibility to hydrological change in the Lower Mekong Basin

The hydrological conditions of the Lower Mekong Basin support a multitude of ecosystem services. Processes that influence water flow in the Mekong River will thus have implications for the tens of millions of people whose livelihoods depend on these services. This study presents an assessment of livelihood susceptibility to hydrological change in the Lower Mekong Basin. Using an index‐based approach, susceptibility scores were calculated for 2,703 households. Using those scores, we compared average household susceptibility across the basin, among countries and among eco‐zones. Due to their greater livelihood dependency on water‐related activities, mean household susceptibility was higher in Vietnam than in Cambodia, Laos, or Thailand. Households in Northern Laos also had high susceptibility, which was attributed to their low adaptive capacity. The findings suggest that policies aimed at reducing vulnerability to hydrological change in the Lower Mekong Basin should account for geographic context. Further, they highlight how policies may be able to strategically target the most susceptible households, but that poorly designed policies have the potential to exacerbate vulnerability. In the face of high uncertainty surrounding hydrological change in the Lower Mekong Basin, our assessment of susceptibility should help inform precautionary water management policies and provide baseline information needed for more comprehensive vulnerability assessments.     

An innovative sustainability assessment for urban wastewater infrastructure and its application in Chengdu, China

Sustainability assessments are an increasingly common tool for measuring progress towards sustainable development. Despite their popularity, sustainability assessments and the indicators that compose them are said to have had little impact on the policy arena. In this paper we discuss four attributes that we contend will improve the use of sustainability assessments to guide decision making: non-compartmentalization, site specificity, built-in guidance for target setting, and ability to measure active sustainability. We present a novel assessment tool for wastewater treatment infrastructure that illustrates these attributes. The assessment is composed of two-dimensional indicators we call “burden to capacity” ratios, that reveal and quantify the local value of resources embodied in wastewater and treatment byproducts, and the tradeoffs between designing systems for disposal versus reuse. We apply the sustainability assessment framework to an existing treatment plant in Chengdu, China and discuss the results.     

The digital workshop: exploring the use of interactive and immersive visualisation tools in participatory planning

This paper examines the emerging role of digital tools in a collaborative planning process for British Columbia's Bowen Island. The goal of this research was to evaluate the effectiveness of a 'digital workshop', combining the interactive CommunityViz tool with the immersive lab facilities at the Collaborative for Advanced Landscape Planning (CALP). In support of the larger community planning process, two 3-h workshops were held at CALP's Landscape Immersion Lab. To facilitate collaborative exploration, the interactive landscape visualisation and real-time data analysis capabilities of CommunityViz were employed to illustrate the possible outcomes of residential density policies for Bowen Island's Snug Cove community. The community planning workshops were structured to provide the 14 semi-expert participants with the opportunity to explore and discuss the contentious residential density components of the draft Snug Cove Village Plan. The abilities to dynamically explore the visualisations of the planning proposals, and to see real-time changes in indicator metrics were considered particularly informative, and appeared to increase participants' understanding of the plan. Written and verbal responses indicated, however, that there was insufficient time to examine and interact with the information during the workshop, suggesting a need to examine in greater depth how and when these tools might best be employed in collaborative settings. Current and future research relating to this project is discussed.     

Growth and elemental accumulation by canola on soil amended with coal fly ash

To explore the agronomic potential of an Australian coal fly ash, we conducted two glasshouse experiments in which we measured chlorophyll fluorescence, CO2 assimilation (A), transpiration, stomatal conductance, biomass accumulation, seed yield, and elemental uptake for canola (Brassica napus) grown on soil amended with an alkaline fly ash. In Experiment 1, application of up to 25 Mg/ha of fly ash increased A and plant weight early in the season before flowering and seed yield by up to 21%. However, at larger rates of ash application A, plant growth, chlorophyll concentration, and yield were all reduced. Increases in early vigor and seed yield were associated with enhanced uptake of phosphorus (P) by the plants treated with fly ash. Fly ash application did not influence accumulation of B, Cu, Mo, or Zn in the stems at any stage of plant growth or in the seed at harvest, except Mo concentration, which was elevated in the seed. Accumulation of these elements was mostly in the leaves, where concentrations of Cu and Mo increased with any amount of ash applied while that of B occurred only with ash applied at 625 Mg/ha. In Experiment 2, fly ash applied at 500 Mg/ha and mixed into the whole 30 cm soil core was detrimental to growth and yield of canola, compared with restricting mixing to 5 or 15 cm depth. In contrast, application of ash at 250 Mg/ha with increasing depth of mixing increased A and seed yield. We concluded that fly ash applied at not more than 25 Mg/ha and mixed into the top 10 to 15 cm of soil is sufficient to obtain yield benefits.     

Effects of Water Withdrawal From Ice‐Covered Lakes on Oxygen,Temperature, and Fish1

Abstract: In northern regions, large volumes of water are needed for activities such as winter road construction. Such withdrawals, particularly from small lakes, can reduce oxygen concentrations and water levels, potentially affecting aquatic organisms. Withdrawal limits have been developed by regulatory agencies, but are largely theoretical. Water withdrawal thresholds were tested in two small lakes by removing 10% and 20% of their respective under‐ice volumes and comparing oxygen parameters, temperature, over‐wintering habitat, and northern pike (Esox lucius) abundance to reference conditions. Because of a milder winter, oxygen parameters were elevated in reference lakes in the period following withdrawal compared to the prewithdrawal period. The 10% withdrawal resulted in a ?0.2 m shift in the oxygen concentration profile at 4 mg/l in that lake, but had no effect on total volume‐weighted oxygen, or volume of over‐wintering habitat. In contrast, the 20% withdrawal caused 0.7 m reduction in the oxygen concentration profile at 4 mg/l compared to the previous year, a 26% decline in the volume‐weighted oxygen concentration, and a 23% reduction in the volume of over‐wintering habitat compared to prewithdrawal conditions. Water temperatures were slightly (≤ 10%) colder in the upper strata in the year following the withdrawal in both withdrawal and reference lakes. Northern pike abundance was not impacted by water withdrawals in either of the lakes. The results of this study show that the effects of water withdrawal on the parameters investigated reflected the characteristics of the lakes, and would therefore be expected to vary from lake to lake. Policy development to mitigate impacts must therefore reflect the site‐specific nature of water withdrawal.