Cystic hygroma: Prenatal diagnosis and genetic counselling

Six cases of cystic hygromas detected during second trimester ultrasound examination are reported: 4 fetuses (67 per cent) had a 45, X karyotype, 1 fetus had trisomy 18, 1 fetus had a normal karyotype (46,XX) and at autopsy multiple anomalies were observed. In the latter case the family history suggested an autosomal recessive pattern of inheritance. In order to reach a definite diagnosis and give proper genetic counselling when a fetus is found to have cystic hygroma, a fetal karyotype as well as a family and reproductive history should be obtained.     

PM2.5 and PM10: The influence of sugarcane burning on potential cancer risk

In Brazil, sugarcane fields are often burned to facilitate manual harvesting, and this burning causes environmental pollution from the large amounts of soot released into the atmosphere. This material contains numerous organic compounds such as PAHs. In this study, the concentrations of PAHs in two particulate-matter fractions (PM_2.5 and PM₁₀) in the city of Araraquara (SE Brazil, with around 200,000 inhabitants and surrounded by sugarcane plantations) were determined during the sugarcane harvest (HV) and non-harvest (NHV) seasons in 2008 and 2009. The sampling strategy included four campaigns, with 60 samples in the NHV season and 220 samples in the HV season. The PM_2.5 and PM₁₀ fractions were collected using a dichotomous sampler (10 L min^?1, 24 h) with Teflon? filters. The filter sets were extracted (ultrasonic bath with hexane/acetone (1:1 v/v)) and analyzed by HPLC/Fluorescence. The median concentration for total PAHs (PM_2.5 in 2009) was 0.99 ng m^?3 (NHV) and 3.3 ng m^?3 (HV). In the HV season, the total concentration of carcinogenic PAHs (benz(a)anthracene, benzo(b)fluoranthene, benzo(k)fluoranthene, and benzo(a)pyrene) was 5 times higher than in the NHV season. B(a)P median concentrations were 0.017 ng m^?3 and 0.12 ng m^?3 for the NHV and HV seasons, respectively. The potential cancer risk associated with exposure through inhalation of these compounds was estimated based on the benzo[a]pyrene toxic equivalence (BaP_eq), where the overall toxicity of a PAH mixture is defined by the concentration of each compound multiplied by its relative toxic equivalence factor (TEF). BaP_eq median (2008 and 2009 years) ranged between 0.65 and 1.0 ng m^?3 and 1.2–1.4 ng m^?3 for the NHV and HV seasons, respectively. Considering that the maximum permissible BaP_eq in ambient air is 1 ng m^?3, related to the increased carcinogenic risk, our data suggest that the level of human exposure to PAHs in cities surrounded by sugarcane crops where the burning process is used is cause for concern.     

Influence of sugar cane vinasse on the sorption and degradation of herbicides in soil under controlled conditions

This study reports the influence of sugar cane vinasse on the persistence, sorption and leaching potential of diuron (3-(3,4-dichlorophenyl)-1,1-dimethylurea), hexazinone (3-cyclohexyl-6-(dimethylamino)-1-methyl-1,3,5-triazine-2,4-dione) and tebuthiuron (1-(5-tert-butyl-1,3,4-thiadiazol-2-yl)-1,3-dimethylurea) in both a clay and sandy soil from a tropical area of Brazil. The experiments were conducted out under controlled laboratory conditions. The addition of sugarcane vinasse to soil influenced the persistence and sorption of the herbicides in both the studied clay and sandy soils, with a considerable decrease in the diuron DT(50) values in clay soil. The Ground Water Ubiquity Score (GUS) Index classifies the herbicides as leachers in both soils and treatments, with the exception of diuron, which is classified as a non-leacher in clay soil-vinasse and as a transient herbicide in sandy soil. These results suggest that special attention should be given to areas such as those where the sandy soil was collected in this study, which is a recharge area of the Guarani Aquifer and is likely to experience groundwater contamination due to the high leaching potential of the applied pesticides.     

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.     

Resistance and re-organization of an ecosystem in response to biological invasion: Some hypotheses

Using a dynamic model of Lake Chozas developed by Marchi et al. (2011), we tested three hypotheses about recovery of the indigenous community and water quality after radical changes caused by introduction of an invasive allochthonous crayfish, Procambarus clarkii:

1.

Can the lake resist the pressure of an invasive species, like P. clarkii, by adaptation?

2.

Can the ecosystem recover when all the crayfish are removed and low phosphorus concentrations persist in inflow water?

3.

Does the simulated recovery of submerged vegetation occur at a total phosphorus concentration below 100 mg TP m⁻³, as estimated by Scheffer et al. (1993), Scheffer (1997), Jeppesen et al. (1998) and Zhang et al. (2003)?

We obtained the following answers:

1.

Lake Chozas can at least partly resist by adaptation. A combination of possible parameter changes could lead to a significant increase in eco-exergy.

2.

Removal of the phosphorus represented by crayfish (by harvesting) implies complete recovery of the lake and its eco-exergy, albeit not necessarily with the same organisms having the same properties.

3.

The expected hysteresis created by introduction and harvesting of crayfish is observed under the following conditions: phytoplankton dominance at total phosphorus ≥ about 200-250 mg TP m⁻³ and submerged vegetation returns at total phosphorus < 100 mg TP m⁻³.

     

RELIABILITY OF THE DESIGN STORM CONCEPT IN EVALUATING RUNOFF PEAK FLOW1

A comparative study was undertaken to evaluate peak runoff flow rates using (1) a continuous series of actual rainfall events and (2) design storms. The ILLUDAS computer model was used to simulate runoff over a catchment within the city of Montreal, Canada. A ten-year period, five-minute increment rainfall data base was used to derive peak flow frequency curves. Two types of design storms were analyzed: one derived from intensity duration frequency curves (Chicago type), the other from averaging actual rainfall patterns (Huff type). Antecedent soil moisture conditions were considered in the analyses. It was found that the probability distribution of runoff peak flow was sensitive to the choice of design storm pattern and to the antecedent soil moisture condition. A symmetrical, Chicago-type design storm with antecedent dry soil moisture produced a flow frequency curve similar to the one obtained from a series of historical rainfall events.     

Analysis of pollution monitoring by expert systems

Pollution monitoring can provide an important aid in the choice of the strategy to control the level of some dangerous elements, whether in water or in the air. The difficulties of detecting polluting sources from experimental data are related not only to the adoption of systematic and suitable measuring procedure, but also to a correct management of the available information. From the theoretical point of view, the use of simplified models, coupled with classical regularization techniques, shows that, in general, the problem is badly posed and consequently, numerically ill-conditioned. Hence the possibility of using expert systems algorithms, introducing further qualitative information, improves the reliability of the solutions. In particular, this paper deals with the utilization of fuzzy optimization algorithms: fuzzy theory supplies a formal reasoning technique, which proposes solutions that are real consequences of the premises.An actual example of such a method is described, making reference to the computation of the distribution of polluting sources from ground concentration data. The inverse problem is first solved using traditional procedures, showing that the distributed sources are not recognized. Afterwards, different results obtained from various algorithms derived from the assumed a-priori knowledge are examined. In this case, it is possible to obtain a more realistic situation of the pollution sources, inside the boundaries of the controlled area.     

Fire risk management system for safe operation of large atmospheric storage tanks

This paper has been prepared by its authors to show the benefits coming from the application of the fire risk assessment methodology prepared by the “LastFire^© Project” group of experts. Now a days this methodology seems to be very effective to face the fire risk connected with large atmospheric storage tanks. It has been developed during the period 1997–2005 the HSE & operations experts from experts 16 worldwide operating oil companies. The authors, by “ad hoc” created software package, show the benefit coming from the applications of the LastFire^© methodology and how, from this, using the methodology and the supporting tad, realize a coherent fire strategy in the form of a Fire Risk Management System. Same workflow could also be extended to the issues connected with other problems related with large atmospheric tanks storing hydrocarbons, such as environmental impact by soil pollution, to create a common frame walk of assessment not can be shared with authorities as well. The proposed methodology, moving from the original project, sets as an effective “Fire Hazard Management Approach” in line with the most recent trends (even enforced by the regulations) shared at international levels, that propose the integration of risk assessment with prevention and protection measures selection based on achieved risk reduction, costs, time needed, etc.