Contamination of Clams with Human Norovirus and a Novel Hepatitis A Virus in Cameroon

Food and Environmental Virology - Shellfish constitute an important protein source but may be contaminated by viruses from various origins. A study performed on clams collected in Cameroon showed a...     

Preliminary estimation of the rainfall chemical composition evaluated through the scavenging modeling for north-eastern Amazonian region (Amapá state,Brazil)

Numerical modeling of scavenging processes has been compared with data obtained for rainwater and aerosol chemistry at Serra do Navio, in the state of Amapá in the Brazilian Amazon region. Sulfate, nitrate and ammonium concentrations were determined in rainwater samples collected from May 1995 until June 1997. The levels of these same chemicals were also determined in aerosols for the same period and region. Scavenging processes have been evaluated on a rainfall event basis, via numerical modeling, in order to simulate the rainwater concentrations and compare them with the observed data. RAMS (Regional Atmospheric Modeling System) was used to simulate cloud structures. A model of below-cloud scavenging was evaluated, as well. The determinations made from the results of the scavenging model are the following: a) aerosol vertical profiles are quite important to rainwater concentrations; b) modeled sulfate in rainwater is a better fit to the observed data values than ammonium and nitrate; c) the obtained sulfate aerosol concentrations samples are similar to ones found in the literature, although the sulfate concentrations in rainwater are much lower than other studies in the literature; d) the in-cloud scavenging process dominates, e) our modeled results, using an input gas vertical profile extracted from the ABLE2B experimental data set, present a smaller ratio between gas and aerosol scavenging than found in other studies in the literature, other studies may have had larger rainfall times, which increase the importance of gas phase scavenging.     

Short-term effects of hydrogen fluoride on Nicotiana tabacum L

Data on the short-term effects of fumigation with hydrogen fluoride (HF) on the response behavior of the Nicotiana tabacum L. cv. St. Karabalar 6265 are being presented. Growth rate, fluoride accumulation in leaves and soils, and degradation in chlorophyll and nicotine contents of the plant species against the variations in two experimental factors, namely the exposure concentration and exposure time parameters, were investigated. Resulting data reveals that the variety selected for this study is not so tolerant to fluoride as generally reported in the literature, if only the individual effects of the pollutant is considered.     

Monitoring the quality of the marine environment

As part of the monitoring program from Instituto Hidrográfico, since 1981 sediment and water samples have been collected from four different estuarine areas located along the continental coast of Portugal. The concentrations of different parameters were measured in the water and sediment samples. After normalization, the concentrations of chromium, mercury, lead and zinc in the sediments from the different areas were compared.     

Monitoring The Turbidity and Surface Temperature Changes and Effects of the 17 August 1999 Earthquake in the İzmİt Gulf,Turkey by the Landsat TM/ETM Data

The temporal turbidity and surface temperature changes and effects of the 17 August 1999 earthquake in the İzmit Gulf, Turkey have been investigated using Landsat TM/ETM data. The gulf is in the Mediterranean–Black Sea transition climatic zone and is partially surrounded by green vegetation cover and degraded and densely urbanized-industrialized areas. Landsat TM/ETM data acquired in 1990–1999 confirms increase in turbidity. Turbidity is always low in the southern part and high in the northern part of the gulf, because the more urbanized and industrialized areas are located in the northern part. The Landsat-7 ETM data acquired in the same year (1999) shows seasonal changes in turbidity. Moreover, the two high turbidity and surface temperature anomalies, one of which is parallel to the 17 August 1999 earthquake surface rupture (east–west) and the other which is in the northwest–southeast direction were mapped from Landsat-5 TM data acquired the day (18.08.1999) following the earthquake in the east end of the gulf. On the basis of turbidity implying the sea bottom movement, it is possible to state that a second rupture in the northwest and southeast direction could have occurred at the sea bottom during the earthquake. The distribution of the seismicity centers and the orientation of the lineaments in the area support this finding.     

Air pollution modelling in Erzurum city

Various techniques have been applied to air pollution modelling. In this study, a model was developed by applying a continuity equation to the air control volume over Erzurum city centre. Model parameters were calculated by regression analysis, using SO2 and particle concentrations taken in 1989-1990 and 1990-1991 winter seasons. Multiple correlation coefficients, R2, for all analyses were of the same order of 97%. According to this model, daily polluting concentrations are not only influenced by daily meterological parameters but also by the values of previous days. The proposed model allows estimation of daily polluting concentrations by means of meteorological data.     

Biosynthesis and Characterization of Laccase Catalyzed Poly(Catechol)

Enzymatic polymerization of catechol was conducted batch-wise using laccase enzyme produced by the culture Trametes versicolor (ATCC 200801). The polymerization reaction was carried out in 1:1 (v/v) aqueous-acetone solution, buffered at pH 5.0 with sodium acetate (50 mM) in a sealed, temperature-controlled reactor at 25°C. The molecular weight of the produced polymer was determined with GPC. FT-IR, DSC, and TGA were employed to investigate the structure and thermal behavior of synthesized poly(catechol). It was found that catechol units were linked together with ether bonds and thermal stability of the catechol increased in the poly(catechol) polymeric structure effectively. The number average molecular weight of poly(catechol) was found as 813 ± 3 Da with a very narrow polydispersity value of 1.17 showing selective polymerization of catechol by the enzyme.