Quality of the surface water of a basin affected by the expansion of the agricultural frontier over the native forest in the Argentine Espinal region

Environmental Science and Pollution Research - Land use changes have led to the degradation of multiple ecosystem services and affected the quality of aquatic ecosystems. The aims of this study...     

The measurement of fine particulate semivolatile material in urban aerosols

Ammonium nitrate and semivolatile organic material (SVOM) are significant components of fine particles in urban atmospheres. These components, however, are not properly determined with methods such as the fine particulate matter (PM2.5) Federal Reference Method (FRM) or other single filter samplers because of significant losses of semivolatile material (SVM) from particles collected on the filter during sampling. The R&P tapered element oscillating microbalance (TEOM) monitor also does not measure SVM, because this method heats the sample to remove particle bound water, which also results in evaporation of SVM. Recent advances in monitoring techniques have resulted in samplers for both integrated and continuous measurement of total PM2.5, including the particle concentrator-Brigham Young University organic sampling system (PC-BOSS), the real-time total ambient mass sampler (RAMS), and the R&P filter dynamics measurement system (FDMS) TEOM monitor. Results obtained using these samplers have been compared with those obtained with either a PM2.5 FRM sampler or a TEOM monitor in studies conducted during the past five years. These studies have shown the following: (1) the PC-BOSS, RAMS, and FDMS TEOM are all comparable. Each instrument measures both the nonvolatile material and the SVM. (2) The SVM is not retained on the heated filter of a regular TEOM monitor and is not measured by this sampling technique. (3) Much of the SVM is also lost during sampling from single filter samplers such as the PM2.5 FRM sampler. (4) The amount of SVM lost from single filter samplers can vary from less than one-third of that lost from heated TEOM filters during cold winter conditions to essentially all during warm summer conditions. (5) SVOM can only be reliably collected using an appropriate denuder sampler. (6) A PM2.5 speciation sampler can be easily modified to a denuder sampler with filters that can be analyzed for semivolatile organic carbon (OC), nonvolatile OC, and elemental carbon using existing OC/elemental carbon analytical techniques. The research upon which these statements are based for various urban studies are summarized in this paper.     

Corruption, political competition and environmental policy

This paper examines the interplay between corruption, political competition, environmental policy and environmental outcomes. An important feature of the model, which has been neglected in the existing literature, is that corruption may occur at different levels of government, such as the payment of bribes to politicians who determine policies, or bureaucrats who administer environmental regulations. We analyse the relationship between political competition and environmental outcomes in a model of stratified corruption and identify the benefits and limits of political competition. Our results suggest that while political competition may yield policy improvements, it cannot eliminate corruption at all levels of government.     

Prenatal diagnosis of multiple acyl-CoA dehydrogenase deficiency: association with elevated α-fetoprotein and cystic renal changes

We report the occurrence of multiple acyl-CoA dehydrogenase deficiency (MADD) in two consecutive pregnancies in a young, Caucasian, non-consanguineous couple. In the first pregnancy, the maternal serum α-fetoprotein was elevated. A sonogram showed growth delay, cystic renal disease, and oligohydramnios; the parents decided to terminate the pregnancy. Postmortem examination confirmed the cystic renal disease and showed hepatic steatosis, raising the suspicion of a metabolic disorder. The diagnosis of MADD was made by immunoblot studies on cultured fibroblasts. In the subsequent pregnancy, a sonogram at 15 weeks' gestation showed an early growth delay but normal kidneys. The maternal serum and amniotic fluid concentrations of α-fetoprotein were elevated, and the amniotic fluid acylcarnitine profile was consistent with MADD. In vitro metabolic studies on cultured amniocytes confirmed the diagnosis. A follow-up sonogram showed cystic renal changes. These cases provide additional information regarding the evolution of renal changes in affected fetuses and show a relationship with elevated α-fetoprotein, which may be useful in counseling the couple at risk. MADD should be considered in the differential diagnosis of elevated α-fetoprotein and cystic renal disease. Early growth delay may be an additional feature. Copyright © 2001 John Wiley & Sons, Ltd.     

Use of object-oriented classification and fragmentation analysis (1985�C2008) to identify important areas for conservation in Cockpit Country, Jamaica

Forest fragmentation is one of the most important threats to global biodiversity, particularly in tropical developing countries. Identifying priority areas for conservation within these forests is essential to their effective management. However, this requires current, accurate environmental information that is often lacking in developing countries. The Cockpit Country, Jamaica, contains forests of international importance in terms of levels of endemism and overall diversity. These forests are under severe threat from the prospect of bauxite mining and other anthropogenic disturbances. In the absence of adequate, up-to-date ecological information, we used satellite remote sensing data and fragmentation analysis to identify interior forested areas that have experienced little or no change as priority conservation sites. We classified Landsat images from 1985, 1989, 1995, 2002, and 2008, using an object-oriented method, which allowed for the inclusion of roads. We conducted our fragmentation analysis using metrics to quantify changes in forest patch number, area, shape, and aggregation. Deforestation and fragmentation fluctuated within the 23-year period but were mostly confined to the periphery of the forest, close to roads and access trails. An area of core forest that remained intact over the period of study was identified within the largest forest patch, most of which was located within the boundaries of a forest reserve and included the last remaining patches of closed-broadleaf forest. These areas should be given highest priority for conservation, as they constitute important refuges for endemic or threatened biodiversity. Minimizing and controlling access will be important in maintaining this core.     

The Effects of Liming On Soil Chemistry at Loch Fleet, Scotland

An experiment to investigate how the water quality of acid lakes can be improved by liming the surrounding catchment was begun at Loch Fleet, Scotland in 1984. the effects on the soils of three sectors of the catchment where limestone was added in 1986 are reported here, following analysis of soils sampled in 1987, 1988 and 1991. the effect of the lime on soil chemistry was still evident in 1991, with about 15% of free lime remaining in the hydrochemical reaction zone of sectors IV and VI and nearly 50% in sector VII. However, this free lime appeared to be dissolving too slowly to maintain large amounts of exchangeable calcium in the soils, indicating that the treatment is starting to become less effective. the fall in the mean exchangeable calcium in the reaction zone between 1988 and 1991 was mirrored by a drop in mean soil pH over the 5 years post-liming from 6.1 to 5.6 on sector IV and from 5.9 to 5.4 on sector VI, whereas mean pH remained constant at about 6.0 in the limed areas of sector VII. Using soil data to predict longevity suggests that the exchangeable calcium remaining on the catchment at the end of 1991 will maintain target water quality in the loch until sometime during 1994. the soil pH is likely to fall to between 5.2 and 5.3 by this time. If the region of hydrochemical reaction is assumed to extend to a depth of 20 cm rather than 5 cm, target water quality is predicted to be maintained until the end of 1995. When the free lime remaining on the catchment is included as a source of acid neutralising capacity, calculations show that treatment may remain effective until around the year 2000.