Elevated ozone affects the genetic composition of Plantago lanceolata L. populations

The genetic composition and diversity of Plantago lanceolata L. populations were analysed using amplified fragment length polymorphism (AFLP) as well as simple sequence repeat (SSR) markers to test for differences in an old semi-natural grassland after five years of treatment with ambient or elevated ozone (O3) using a free-air fumigation system. Genetic diversity in populations exposed to elevated O3 was slightly higher than in populations sampled from control plots. This effect was significant for AFLP-based measures of diversity and for SSR markers based on observed heterozygosity. Also, a small but significant difference in genetic composition between O3 treatments was detected by analysis of molecular variance and redundancy analysis. The results show that micro-evolutionary processes could take place in response to long-term elevated O3 exposure in highly diverse populations of outbreeding plant species.     

Cytological study and immunohistochemical location of PSP toxins in foot skin of the ormer, Haliotis tuberculata, from the Galician coast (NW Spain)

The ormer, Haliotis tuberculata Linnaeus, 1758, is able to accumulate paralytic shellfish toxins (PST) in the foot side skin. Epidermal and secretory cells are described separately for the pedal side and sole epithelia, as notable differences have been observed. Melanin and photosynthetic pigment granules in the epidermal cells of the foot side epithelium give this skin its appearance and characteristic color. This epidermis also has abundant secretory cells containing at least three kinds of secretory granules. Conversely, the epidermal cells of foot sole epithelium do not have pigment granules, and the secretory cells are mostly subepithelial. Immunohistochemical reaction against PST (saxitoxin and its derivatives) showed that the toxins are located in specific cells of the foot side epithelium, which are distinct from the epidermal cells. Immunofluorescence also reveals toxins throughout many areas of the mucilage covering the epithelium, suggesting the secretory nature of the cells containing the toxins. These results do not show any apparent relationship between melanin or photosynthetic pigment granules and PST content. PST were not detected in the foot sole epithelium either immunohistochemically or by HPLC. Considering the toxic characteristics of ormers described in previous studies and the results presented here, the authors discuss the role of toxins retained or produced by the foot side epithelium Received: 25 July 2000 / Accepted: 7 November 2000     

Transverse limb reduction defects after chorion villus sampling: A retrospective Cohort study

A retrospective cohort study was performed in five Italian obstetrical centres from 1984 to 1991 in order to verify the association between chorionic villus sampling (CVS) and transverse limb reduction defects (TLRDs). TLRD rates by period of gestation at CVS were calculated, and the study's results were compared with data from the general population. Of the 3430 pregnancies for which CVS was performed, 2759 had a known outcome. The overall rate for TLRDs was 1 in 1143 CVS pregnancies, four times higher than that of the general population in Italy (1 in 4458). The rate of TLRDs was 2·9/1000 for CVS performed at 9 weeks' gestation and 1·0/1000 for CVS at 10 weeks' gestation. A scalp defect was detected in a pregnancy in which CVS was performed at 10 weeks. A high proportion of pregnancies lost to follow-up and the poor quality of the data may have affected the results. Nevertheless, our results suggest an association between CVS carried out at less than 10 weeks' gestation and TLRDs which is consistent with the findings of other studies. CVS should not be prepared at less than 10 weeks' gestation until additional evidence is obtained.     

Assessment of natural arsenic in groundwater in Cordoba Province,Argentina

Groundwater in the central part of Argentina contains arsenic concentrations that, in most cases, exceed the value suggested by international regulations. In this region, Quaternary loessical sediments with a very high volcanic glass fraction lixiviate arsenic and fluoride after weathering. The objectives of this study are to analyze the spatial distribution of arsenic in different hydrogeological regions, to define the naturally expected concentration in an aquifer by means of hydrogeochemistry studies, and to identify emergent health evidences related to cancer mortality in the study area. The correlation between arsenic and fluoride concentrations in groundwater is analyzed at each county in the Cordoba Province. Two dimensionless geoindicators are proposed to identify risk zones and to rapidly visualize the groundwater quality related to the presence of arsenic and fluoride. A surface-mapping system is used to identify the spatial variability of concentrations and for suggesting geoindicators. The results show that the Chaco-Pampean plain hydrogeologic region is the most affected area, with arsenic and fluoride concentrations in groundwater being generally higher than the values suggested by the World Health Organization (WHO) for drinking water. Mortality related to kidney, lung, liver, and skin cancer in this area could be associated to the ingestion of arsenic-contaminated water. Generated maps provide a base for the assessment of the risk associated to the natural occurrence of arsenic and fluoride in the region.     

Effective removal of non-steroidal anti-inflammatory drug from wastewater by adsorption process using acid-treated Fagopyrum esculentum husk

Environmental Science and Pollution Research - In this work, buckwheat husks (Fagopyrum esculentum) were modified by acid treatment and posteriorly employed to remove the ketoprofen in batch...     

Ozone sensitivity of currant tomato (Lycopersicon pimpinellifolium), a potential bioindicator species

The wild tomato species Lycopersicon pimpinellifolium (currant tomato) was exposed to different O3 concentration, both in controlled environment fumigation facilities and in open-top chambers, to assess its sensitivity and to verify its potential as a bioindicator plant. Plants appeared particularly sensitive to O3 at an early stage of growth, responding with typical chlorotic spots within 24 h after exposure to a single pulse of 50 ppb for 3 h, and differentiating peculiar symptoms, such as reddish necrotic stipples, bronzing and extensive necrosis, depending on O3 concentration. Histo-cytochemical investigations with 3,3'-diaminobenzidine, to localize H2O2, and Evans blue, to detect dead cells, suggested that currant tomato sensitivity to O3 could be due to a deficiency in the anti-oxidant pools. The combination of these stainings proved to be useful, either to predict visible symptoms, early before their appearance, and to validate leaf ozone injury.     

Diel periodicity of pheromone release by females of Planococcus citri and Planococcus ficus and the temporal flight activity of their conspecific males

The diel periodicity of sex pheromone release was monitored in two mealybug species, Planococcus citri and Planococcus ficus (Hemiptera; Pseudococcidae), using sequential SPME/GCMS analysis. A maximal release of 2 ng/h pheromone by 9–12-day-old P. citri females occurred 1–2 h before the beginning of photophase. The highest release of pheromone by P. ficus females was 1–2 ng/2 h of 10–20-day-old females, approximately 2 h after the beginning of photophase. Mating resulted in termination of the pheromone release in both mealybug species. The temporal flight activity of the males was monitored in rearing chambers using pheromone baited delta traps. Males of both P. citri and P. ficus displayed the same flight pattern and began flying at 06:00 hours when the light was turned on, reaching a peak during the first and second hour of the photophase. Our results suggest that other biparental mealybug species display also diel periodicities of maximal pheromone release and response. Direct evaluation of the diel periodicity of the pheromone release by the automatic sequential analysis is convenient and will be very helpful in optimizing the airborne collection and identification of other unknown mealybug pheromones and to study the calling behavior of females. Considering this behavior pattern may help to develop more effective pheromone-based management strategies against mealybugs.     

Is there a double-dividend from anti-sprawl policies?

This paper examines the welfare effects of anti-sprawl policies, such as development tax, in a simple spatial explicit urban model with two market failures - urban decline at the city core and underprovision of open space amenities at the urban fringe - and pre-existing distortionary property tax, used to fund public services and improvements to mitigate urban decline. Consistent with prior double-dividend literature, there is a tax interaction effect that occurs between the development tax and the pre-existing property tax. However, there are two fundamental differences between the tax interaction effect identified here and that of prior literature. Ours one has two components: First, there is a cost-side tax interaction effect that is ‘spatially’ concentrated at the urban fringe, as only agents at the urban fringe alter their behavior in response to the development tax. Second, there is also a benefit-side tax interaction effect, as increases in open space at the urban fringe are capitalized into housing prices throughout the city. In contrast to prior literature, we find that the empirical importance of the combined tax interaction effect is of substantially less importance and, as a consequence, the likelihood of a ‘double-dividend’ is higher than in prior studies. Further, we show that the development tax should be part of the local tax system, even in the absence of open space benefits.