Matrine and oxymatrine in corroborant plant extracts and fertilizers: HPLC/MS-MS method development and single-laboratory validation

A reversed phase high-performance liquid chromatographic method (HPLC/MS-MS) has been developed and validated for detection of alkaloids matrine and oxymatrine in fertilizer with labeled enhancer plant defense activities. The analytical method was validated statistically. The results show a strong matrix effect, requiring quantification by standard addition method. The regression lines showed r² > 0.994. Recoveries ranging from 97 to 104% were obtained for the fortification level of 0.01% wt wt^?1 and the relative standard deviations ranged from 3 to 4% (n = 10). The limits of detection were below 0.0001% wt wt^?1, while the limits of quantification did not exceed 0.0004% wt wt^?1. The method is currently applied in ICQRF Laboratory of Catania on fertilized and corroborant plant extract collected in the Italian market in the frame of MIPAAF institutional quality control activity, with the aim to dectect these unpermitted active substances.     

Contrasting structure and composition of the understory in species-rich tropical rain forests

In large samples of trees > or = 1 cm dbh (more than 1 million trees and 3000 species), in six lowland tropical forests on three continents, we assigned species with >30 individuals to one of six classes of stature at maturity (SAM). We then compared the proportional representation of understory trees (1-2 cm dbh) among these classes. The understory of the three Asian sites was predominantly composed of the saplings of large-canopy trees whereas the African and American sites were more richly stocked with trees of the smaller SAM classes. Differences in class representation were related to taxonomic families that were present exclusively in one continent or another. Families found in the Asian plots but not in the American plot (e.g., Dipterocarpaceae, Fagaceae) were predominantly species of the largest SAM classes, whereas families exclusive to the American plots (e.g., Melastomataceae sensu stricto, Piperaceae, and Malvaceae [Bombacacoidea]) were predominantly species of small classes. The African plot was similar to Asia in the absence of those American families rich in understory species, while similar to America in lacking the Asian families rich in canopy species. The numerous understory species of Africa were chiefly derived from families shared with Asia and/or America. The ratio of saplings (1-2 cm dbh) to conspecific canopy trees (>40 cm dbh) was lower in American plots than in the Asian plots. Possible explanations for these differences include phenology, moisture and soil fertility regimes, phyletic constraints, and the role of early successional plants in forest development. These results demonstrate that tropical forests that appear similar in tree number, basal area, and the family taxonomy of canopy trees nonetheless differ in ecological structure in ways that may impact the ecology of pollinators, dispersers, and herbivores and might reflect fundamental differences in canopy tree regeneration.     

Evolutionary relationships of deep-sea mussels inferred by mitochondrial DNA sequences

In order to elucidate the evolutionary process of deep-sea Bathymodiolus mussels, we investigated the phylogenetic relationships of 16 species worldwide by analyzing nucleotide sequences of the mitochondrial COI and ND4 genes. Deep-sea mussels were clustered into three groups by basal trichotomous divergence. The first was composed of four species found in Japanese waters and one species from the Gulf of Mexico, which contain methanotrophic endosymbiotic bacteria. The second included nine species distributed in the West and East Pacific, Indian, and Atlantic Oceans. Members of the second group were trichotomously divided into the Indo-West Pacific, Atlantic, and East Pacific subclusters. The Indo-West Pacific subcluster was composed of three very closely related species with mutual genetic distances at the intraspecific level (av. 0.019 in COI and 0.009 in ND4 relative to av. 0.156 in COI and 0.265 in ND4 among Bathymodiolus species other than Cluster A species), suggesting some gene flow among these species. The third consisted of two West Pacific species. Species in the second and third groups contain mainly thioautotrophic endosymbionts, including some species harboring both methanotrophs and thioautotrophs.     

Integrating Remote Sensing Approach with Pollution Monitoring Tools for Aquatic Ecosystem Risk Assessment and Managment: A Case Study of Lake Victoria(UGANDA)

Aquatic ecosystems around the world, lake, estuaries and coastal areas are increasingly impacted by anthropogenic pollutants through different sources such as agricultural, industrial and urban discharges, atmospheric deposition and terrestrial drainage. Lake Victoria is the second largest lake in the world and the largest tropical lake. Bordered by Tanzania, Uganda, and Kenya, it provides a livelihood for millions of Africans in the region. However, the lake is under threat from eutrophication, a huge decline in the number of native fish species caused by several factors including loss of biodiversity, over fishing and pollution has been recently documented. Increasing usage of pesticides and insecticides in the adjacent agricultural areas as well as mercury contamination from processing of gold ore on the southern shores are currently considered among the most emergent phenomena of chemical contamination in the lake. By the application of globally consistent and comprehensive geospatial data-sets based on remote sensing integrated with information on heavy metals accumulation and insecticides exposure in native and alien fish populations, the present study aims at assessing the environmental risk associated to the contamination of the Lake Victoria water body on fish health, land cover distribution, biodiversity and the agricultural area surrounding the lake. By the elaboration of Landsat 7 TM data of November 2002 and Landsat 7 TM 1986 we have calculated the agriculture area which borders the Lake Victoria bay, which is an upland plain. This process has greatly enhanced nutrient loading to the soil, which is subsequently transported to the lake by rain or as dry fall. All the data has been insert in the Geographical information System (ARCGIS) to be upgraded and consulted. Heavy metals in fish fillets showed concentrations rather low except for mercury being higher than others as already described in previous investigations. In the same tissue, cholinesterases activity (ChE) as an indicator of insecticides exposure showed significant differences among fish species in both activity and sensitivity of selected inhibitor insecticides. This integrated approach aims at identifying and quantifying selected aquatic environmental issues which integrated with monitoring techniques such as contaminant concentrations and biological responses to insecticides exposure in fish populations will provide a scientific basis for aquatic zones management and assist in policy formulations at the national and international levels.     

Temporal and spatial changes in primary biomass as a diagnosis and prognosis in environmental impact (Rapel Reservoir,Central Chile)

Extensive mortality of silversides (Atherinidae), Odontesthes bonariensis, was recorded during July 1989 in the Rapel Reservoir. Temporal and spatial changes observed in biomass concentration (chlorophyll-a) through both ground and remote sensing samples (LANDSAT), allowed us to establish a potential environmental impact. Ground measurements established an input of sulfate (SO₄) in a eutrophic area. The mean concentration of biomass tended to decrease in this area in comparison with other mesotrophic areas. The local disfunction associated with the observed biomass changes has been used to develop a prediction in species composition and in biomass concentration.

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Resumen Durante la primera semana de Julio de 1989, se registró una muerte masiva de pejerreyes, Odontesthes bonariensis en el Embalse Rapel. En los procesos de monitoreo de la calidad de agua en el Embalse Rapel, se utilizó una representacion espacial primaria de las variables de estado elegidas. Las tendencias témporo-espaciales observadas en la concentración de biomasa fitoplanctónica (clorofila-a) permitieron establecer un impacto ambiental potencial por un agente exógeno al sistema. A partir de mediciones de terreno se estableció la presencia de sulfato (SO₄) en una zona de características eutróficas. Los efectos observados en esta zona, en comparación al resto del embalse, fueron una disminución en la concentración media de la biomasa. La disfunción local observada, permitió sustentar una prognosis asociada a la composición de especies fitoplanctónicas y la concentración de biomasa local.

     

Seasonal contrasts in abundance and reproductive parameters of Penilia avirostris (Cladocera, Ctenopoda) in a coastal subtropical area

We studied the population dynamics and the reproductive biology of Penilia avirostris during three consecutive years on the inner shelf off Ubatuba, Brazil. Penilia avirostris individuals and its eggs and embryos were counted, measured, and classified into stages. The species occurred throughout the studied period, in a wide temperature range (14.8–28.2°C). Cladoceran densities were usually higher (>2,000 ind m⁻³) in warm seasons, when the water column was stratified as a consequence of bottom intrusions of the cold- and nutrient-rich South Atlantic Central Water. Juveniles, non-reproducing females, and parthenogenic females were the dominant developmental stages. Males and gamogenic females were rare and only occurred when females reached peak abundances. This suggests that in tropical and subtropical coastal seas gamogenesis in P. avirostris is not as common as in temperate seas, but may play a significant role in the density-dependent control of the population preceding unfavourable periods.     

Assessment of heavy metals in the particulate matter of two Brazilian metropolitan areas by using <Emphasis Type=BoldItalic>Tillandsia usneoides</Emphasis> as atmospheric biomonitor

Purpose  

The aims of this paper were to quantify the heavy metals (HM) in the air of different sites in Rio de Janeiro (RJ) and Salvador (SA) using Tillandsia usneoides (Bromeliaceae) as a biomonitor, and to study the morphology and elemental composition of the air particulate matter (PM) retained on the Tillandsia surface.     

Microsatellite data reveal fine genetic structure in male Guiana dolphins (<Emphasis Type="Italic">Sotalia guianesis)</Emphasis> in two geographically close embayments at south-eastern coast of Brazil

A large macrogeographic differentiation has been observed among Sotalia guianensis populations along the South American coast. However, no genetic structure has been detected so far in closely distributed populations of this species, even though it has been observed in other cetaceans. Here, we examined the fine scale population structure for the largest populations of S. guianensis inhabiting Sepetiba and Paraty embayments at the south-eastern coast of Rio de Janeiro, Brazil. Analysis of mitochondrial DNA (mtDNA) control region sequences failed to detect variability among sequences. Conversely, evidence of significant male population structure was found on the basis of ten nuclear microsatellite loci. Surprisingly, the microsatellite markers were able to distinguish between individuals from the two embayments located 60 km apart. The results suggest that differences in habitat type and behavioral specializations are likely to explain the patterns of genetic structure. These findings should provide baselines for the management of communities exposed to increasing human-driven habitat loss.     

Comparison of real-time instruments and gravimetric method when measuring particulate matter in a residential building

This study used several real-time and filter-based aerosol instruments to measure PM_2.5 levels in a high-rise residential green building in the Northeastern US and compared performance of those instruments. PM_2.5 24-hr average concentrations were determined using a Personal Modular Impactor (PMI) with 2.5 µm cut (SKC Inc., Eighty Four, PA) and a direct reading pDR-1500 (Thermo Scientific, Franklin, MA) as well as its filter. 1-hr average PM_2.5 concentrations were measured in the same apartments with an Aerotrak Optical Particle Counter (OPC) (model 8220, TSI, Inc., Shoreview, MN) and a DustTrak DRX mass monitor (model 8534, TSI, Inc., Shoreview, MN). OPC and DRX measurements were compared with concurrent 1-hr mass concentration from the pDR-1500. The pDR-1500 direct reading showed approximately 40% higher particle mass concentration compared to its own filter (n = 41), and 25% higher PM_2.5 mass concentration compared to the PMI_2.5 filter. The pDR-1500 direct reading and PMI_2.5 in non-smoking homes (self-reported) were not significantly different (n = 10, R² = 0.937), while the difference between measurements for smoking homes was 44% (n = 31, R² = 0.773). Both OPC and DRX data had substantial and significant systematic and proportional biases compared with pDR-1500 readings. However, these methods were highly correlated: R² = 0.936 for OPC versus pDR-1500 reading and R² = 0.863 for DRX versus pDR-1500 reading. The data suggest that accuracy of aerosol mass concentrations from direct-reading instruments in indoor environments depends on the instrument, and that correction factors can be used to reduce biases of these real-time monitors in residential green buildings with similar aerosol properties.

Implications: This study used several real-time and filter-based aerosol instruments to measure PM_2.5 levels in a high-rise residential green building in the northeastern United States and compared performance of those instruments. The data show that while the use of real-time monitors is convenient for measurement of airborne PM at short time scales, the accuracy of those monitors depends on a particular instrument. Bias correction factors identified in this paper could provide guidance for other studies using direct-reading instruments to measure PM concentrations.     

Great Basin Land Management Planning Using Ecological Modeling

This report describes a land management modeling effort that analyzed potential impacts of proposed actions under an updated Bureau of Land Management Resource Management Plan that will guide management for 20 years on 4.6 million hectares in the Great Basin ecoregion of the United States. State-and-transition models that included vegetation data, fire histories, and many parameters (i.e., rates of succession, fire return intervals, outcomes of management actions, and invasion rates of native and nonnative invasive species) were developed through workshops with scientific experts and range management specialists. Alternative restoration scenarios included continuation of current management, full fire suppression, wildfire use in designated fire use zones, wildfire use in resilient vegetation types only, restoration with a tenfold budget increase, no restoration treatments, and no livestock grazing. Under all the scenarios, cover of vegetation states with native perennial understory declined and was replaced by tree-invaded and weed-dominated states. The greatest differences among alternative management scenarios resulted from the use of fire as a tool to maintain native understory. Among restoration scenarios, only the scenario assuming a tenfold budget increase had a more desirable outcome than the current management scenario. Removal of livestock alone had little effect on vegetation resilience. Rather, active restoration was required. The predictive power of the model was limited by current understanding of Great Basin vegetation dynamics and data needs including statistically valid monitoring of restoration treatments, invasiveness and invasibility, and fire histories. The authors suggest that such computer models can be useful tools for systematic analysis of potential impacts in land use planning. However, for a modeling effort to be productive, the management situation must be conducive to open communication among land management agencies and partner entities, including nonprofit organizations.