Thyroid antibodies are not a risk factor for pregnancies with down syndrome

The observation that thyroid disease is frequent in mothers of children with Down syndrome (DS) has suggested that maternal thyroid antibodies could be a factor predisposing to trisomy 21 in their offspring. In this study, the incidences of thyroglobulin (Tg) and thyroid peroxidase (TPO) antibodies were analysed with a sensitive solid-phase immunosorbent radioassay in sera from 29 mothers giving birth to children with trisomy 21 and 87 control mothers. The serum samples were collected at delivery. There was no statistical difference regarding the proportion of thyroid antibodies (against Tg and/or TPO) in the two groups. Thyroid antibodies were detected in 6/29 (20.7 per cent) of the DS mothers and in 23/87 (26.4 per cent) of the control mothers. Among the women with thyroid antibodies, 4/6 (66.7 per cent) of the DS mothers and 12/23 (52 per cent) of the control mothers had antibodies against both Tg and TPO. There was no increase in the relative risk of having a child with DS if the titre of either Tg or TPO antibodies or both were positive, i.e. ≥ 1/5. The results indicate that the presence of thyroid antibodies in the serum of a pregnant woman has no prognostic value for the birth of an infant with DS.     

Role of the vitamin E model compound Trolox in the prevention of Cr(VI)-induced cellular damage

Given the wide industrial use of chromium (Cr) and its environmental contamination, chromium represents a risk to humans exposed to the metal. Considering that Cr(VI) is a potent oxidizing agent that increases intracellular oxidation and DNA damage, it would be worth considering the pretreatment of cells with antioxidants as a means of preventing Cr(VI)-induced toxicity. The objective of this study was to pretreat yeast cells with the water-soluble vitamin E analogue Trolox in an effort to increase cell tolerance against reactive chromium and reactive oxygen species formed during Cr(VI) reduction. Results revealed a decrease in Cr(VI)-induced cytotoxicity and mitotic gene conversions in Trolox-pretreated cells. The protective effect of Trolox in Cr(VI) induced genotoxicity was confirmed also with the prokaryotic Salmonella typhimurium SOS/umu test. Pretreatment of cells with Trolox (1) increased total Cr bioaccumulation, (2) decreased Cr(VI)-induced intracellular oxidation, (3) decreased Cr(V) persistence and (4) increased OH^? formation in yeast extracts. These findings might be useful in directing future investigations concerning the use of Trolox as a human antioxidant supplement, and in clinical applications related to Cr-induced genotoxicity in occupational and environmental situations where chromium is a problem.     

Investigating biodiversity trajectories using scenarios – Lessons from two contrasting agricultural landscapes

Agriculture is the major land use at a global scale. In addition to food production, multifunctionality of landscapes, including values and ecosystem services like biodiversity, recreation and culture, is now focus for management. This study explores how a scenario approach, involving different stakeholders, may help to improve landscape management for biodiversity conservation. Local farmers and executives at the County Administrative Board were invited to discuss rural development and conditions for farmland biodiversity in two Swedish landscapes. The potential biodiversity for three future land use scenarios for the two landscapes was discussed: nature conservation, outdoor recreation and energy production, and compared with current and historical landscapes in each region.Analyses of habitat areas, connectedness and landscape diversity suggested that the energy and recreation scenarios had a negative impact on farmland biodiversity, whereas the nature conservation scenario, the current and historically reconstructed landscapes had a higher potential for biodiversity. The farmers appreciated the nature conservation scenario, but also the energy production scenario and they highlighted the need of increased subsidies for management of biodiversity. The farmers in the high production area were less interested in nature quality per se. The executives had similar opinions as the farmers, but disagreed on the advantages with energy production, as this would be in conflict with the high biodiversity and recreational values. The local physical and socio-economical conditions differ between landscapes and potentially shaped the stakeholders emotional attachment to the local environment, their opinions and decisions on how to manage the land. We stress the importance of incorporating local knowledge, visions and regional prerequisites for different land uses in conservation, since site and landscape specific planning for biodiversity together with a flexible subsidy system are necessary to reach the conservation goals within EU.     

CO2 storage capacity estimation: Methodology and gaps

Implementation of CO₂ capture and geological storage (CCGS) technology at the scale needed to achieve a significant and meaningful reduction in CO₂ emissions requires knowledge of the available CO₂ storage capacity. CO₂ storage capacity assessments may be conducted at various scales—in decreasing order of size and increasing order of resolution: country, basin, regional, local and site-specific. Estimation of the CO₂ storage capacity in depleted oil and gas reservoirs is straightforward and is based on recoverable reserves, reservoir properties and in situ CO₂ characteristics. In the case of CO₂-EOR, the CO₂ storage capacity can be roughly evaluated on the basis of worldwide field experience or more accurately through numerical simulations. Determination of the theoretical CO₂ storage capacity in coal beds is based on coal thickness and CO₂ adsorption isotherms, and recovery and completion factors. Evaluation of the CO₂ storage capacity in deep saline aquifers is very complex because four trapping mechanisms that act at different rates are involved and, at times, all mechanisms may be operating simultaneously. The level of detail and resolution required in the data make reliable and accurate estimation of CO₂ storage capacity in deep saline aquifers practical only at the local and site-specific scales. This paper follows a previous one on issues and development of standards for CO₂ storage capacity estimation, and provides a clear set of definitions and methodologies for the assessment of CO₂ storage capacity in geological media. Notwithstanding the defined methodologies suggested for estimating CO₂ storage capacity, major challenges lie ahead because of lack of data, particularly for coal beds and deep saline aquifers, lack of knowledge about the coefficients that reduce storage capacity from theoretical to effective and to practical, and lack of knowledge about the interplay between various trapping mechanisms at work in deep saline aquifers.     

WATER MANAGEMENT IN ONTARIO1

ABSTRACT: The Ontario Ministry of the Environment has based its water quality management approach on a set of guidelines published in 1970. In light of the changing societal and economic background, advancement in technology and scientific knowledge, and philosophical attitudes towards water management, the water management program was recently revised. Factors influencing the revised approach, including federal-provincial interrelationships and international commitments under the Canada-U.S. Agreement, are summarized. The revised program consists of a goal statement, policies to implement this goal, revised water quality objectives, and detailed implementation procedures for field staff use. Rather than promulgating regulations to impose arbitrary effluent or receiving water standards on a province-wide basis, the revised approach involves the imposition of legally enforceable effluent requirements on a case-by-case basis. Although the paper emphasizes the surface water quality program, it also outlines the Ministry's goals, policies, and procedures for the management of surface-water quantity, as well as ground water quality and quantity.     

Model simulations of dissolved oxygen characteristics of Minnesota lakes: Past and future

A deterministic, one-dimensional, unsteady numerical model has been developed, tested, and applied to simulate mean daily dissolved oxygen (DO) characteristics in 27 lake classes in the state of Minnesota. Reaeration and photosynthesis are the oxygen sources, while respiration, sedimentary, and biochemical water column oxygen demand are the sinks of oxygen in the model. The lake classes are differentiated by surface area (A _s), maximum depth (H _max), and trophic status expressed as Secchi depth (Z _s). Because lake stratification is most important to lake oxygen dynamics, simulated DO characteristics are plotted in terms of a stratification parameterA _s/H _max ^0.25 and Secchi depthZ _s. Simulations provide DO profiles on a daily time scale. Specific DO characteristics of ecological and environmental interest are epilimnetic DO, hypolimnetic DO, DO gradient from surface to bottom, and DO minima and maxima. Specific results are as follows: Simulated mean daily and weekly DO values in the epilimnion of all lakes for both past and future climate scenarios are near saturation over the summer season. Hypolimnetic DO values depend strongly on lake morphometry, trophic status, and time throughout the summer season. Future climate conditions are specified as the historical records from 1955 to 1979, adjusted (monthly) by the 2 × CO₂ GISS model output to account for doubling of atmospheric CO₂. With this climate change, weekly averaged epilimnetic DO is projected to drop by less than 2 mg/liter, and will remain above 7 mg/liter throughout the open water season. The hypolimnetic DO reductions after climate change are on the order of 2–8 mg/liter. Periods of anoxia are longer by as much as 80 days. Those changes would alter water quality dynamics in lakes and have a profound effect on lake ecosystems including indigenous fishes. The results presented are useful for evaluating environmental management options.     

ANALYSIS OF WIND- AND SHIP-INDUCED SEDIMENT RESUSPENSION IN DULUTH-SUPERIOR HARBOR1

ABSTRACT: Suspended solids and ammonium concentration profiles measured at five locations in Duluth-Superior Harbor during July-October 1985 were analyzed to quantify wind and ship effects on sediment resuspension and resulting harbor water quality. Wind components from the SE quadrant correlated strongly with depth-averaged suspended solids concentrations that were unaffected by ship passage or thermal stratification. Winds from that quadrant have the largest fetch in the harbor. The highest correlation (r²= 0.93) was with the 6-hour average of the ESE wind velocity component. Multiple linear regression analysis of data from post-ship passage concentration profiles yielded numerical estimates of settling velocities of 0.08 to 0.25 cm s^?1, typical of ship-resuspended sediments, and vertical eddy diffusivities of 4 to 13 cm² s¹. The results suggest that ambient vertical eddy diffusivities in the harbor are less than 4 cm² s^?1 in the absence of ship passages and with winds less than 5 m s^?1 (10 knots).     

Climate policy support under political consensus: exploring the varying effect of partisanship and party cues

By creating attitudinal rifts among partisan voters, political polarization is expected to negatively affect chances of effectively mitigating climate change. While such expectations generally have found support, less attention has been paid to the opposite claim that political consensus should eliminate the partisan dimension in climate change politics. This study tests this claim by studying how party identification, and party cues specifically, affects public policy attitudes in a context defined by political consensus. Using data from a large online access panel in Sweden, party identification and party cues are shown to matter for policy attitudes even in a consensus context. This effect is not limited to certain issues but is found across a wide range of policies, and the effect of party cues, for a given issue, varies across parties. The implications of this study and areas for future work are discussed.     

Modeling the exposure of children and adults via diet to chemicals in the environment with crop-specific models

Exposure to chemicals via diet is a major uptake pathway for many compounds but is often estimated in a rather generic way. We use a new model framework (NMF) with crop-specific models to predict the dietary intake by 4-5-year-old children and 14-75-year-old women of three environmental compounds from their background concentrations in soil and air. Calculated daily intakes of benzo(a)pyrene and 2,3,7,8-TCDD are in good agreement with measured results from diet studies. The major source of both compounds in human diet is deposition from air. Inhalation of air and ingestion of soil play a minor role. Children take up more than twice the amount than adults per kg bodyweight, due to higher consumption per kg bodyweight. Contrary, the methods for indirect human exposure suggested in the Technical Guidance Document (TGD) for chemical risk assessment in the EU lead to overprediction, due to unrealistic consumption data and a false root model.     

Sex-specific effects of parasites on telomere dynamics in a short-lived passerine—the blue tit

The pollination syndrome concept implies that flowers evolved with particular sets of characteristics, such as colors, shapes, orientations, and rewards, as a means of attracting pollinators. However, these traits may have also evolved to deter unwanted visitors. The North American genus Penstemon exhibits a great floral diversity that is mainly associated with bumblebee and hummingbird pollination. Evolutionary shifts from insect pollination to hummingbird pollination have occurred in Penstemon repeatedly, but some species maintain mixed-pollination systems and intermediate floral traits between bee- and hummingbird-pollination modes. The apparently intermediate floral traits of species with mixed-pollination systems might be potentially acting to deter bumblebee foragers. Then, bird-flower traits might be selected with increased hummingbird visitation over evolutionary time might, resulting in specialization to and the evolution of floral traits present in hummingbird-pollinated species. Here, we modified bee-pollination floral traits in Penstemon gentianoides with a mixed pollination system, to resemble hummingbird-pollination traits, and measured the effects of trait modification on bumblebee foraging behavior and plant female reproductive fitness. Our results showed that reduction in the width of the corolla tube and the absence of the corolla lip negatively affects bumblebee visitation and their efficiency as pollinators, and that the synergistic interaction of both traits enhanced the “anti-bee” effect. We conclude that acquisition of floral traits that resemble those of hummingbird-pollination enables Penstemon plant species to deter bumblebee visits.