Comparison of a matrix solid phase dispersion and a classical extraction method for the determination of chlorinated pesticides in fish muscle

A new multiresidue extraction technique was used to determine incurred chlorinated hydrocarbon pesticide residues in various fish species sampled at 2 locations along the Tensas River in Louisiana. Residue levels of total DDT (combined DDT, DDE, and DDD levels) in fish muscle fillets from paired samples ranged from 0.2 to 3.9 ppm on a wet weight basis. These findings were compared to those of another laboratory that used a different protocol to isolate the residues from the fish muscle fillets. This latter protocol typifies the more complicated, time-consuming protocols used by governmental agencies for screening purposes. Results demonstrated that the new extraction technique reduced analysis time, solvent waste, and cost per sample without affecting the quality of residue detection and measurement.     

Sustainable Use of the Tropical Rain Forest: Evidence from the Avifauna in a Shifting-Cultivation Habitat Mosaic in the Colombian Amazon

We carried out a one-year study of the avifauna along a regeneration gradient created by indigenous shifting cultivation in the Colombian Amazon rain forest. Regenerating one-hectare crop fields, from 1 to 17 years after abandonment, and undisturbed understory sites were compared in a sample effort of 4323 net hours. We made 878 captures of 103 species belonging to 11 trophic groups. Differences in species richness and number of individuals captured between regenerating areas and primary forest were low. A comparison of similarity indices among the sites for each habitat type showed no consistent differences, suggesting similar levels of local heterogeneity. Similarity indices calculated between sites of different-aged habitats, however, showed that young secondary growth at less than 10 years of abandonment was least similar to other sites, whereas old secondary growth between 13 to 17 years of abandonment, and forest understories, had the most similar avifauna. Two trophic groups were absent from the samples of the forest interior, and the abundance of the other nine varied among sites of regeneration. We conclude that slash and burn agriculture represents a high-intensity, small-magnitude disturbance to the forest avifauna. Large changes occur when the crop field is established and last until about 10 years after abandonment. Our data suggest that abandoned crop fields older than this age mimic the natural patch dynamics of the forest, making this type of agriculture an example of a potentially sustainable use of tropical forests, at least from the standpoint of its impact on bird communities.     

Near-term ecological forecasting for dynamic aeroconservation of migratory birds

Near-term ecological forecasting has the potential to mitigate negative impacts of human modifications on wildlife by directing efficient action through relevant and timely predictions. We used the U.S. avian migration system to highlight ecological forecasting applications for aeroconservation. We used millions of observations from 143 weather surveillance radars to construct and evaluate a migration forecasting system for nocturnal bird migration over the contiguous United States. We identified the number of nights of mitigation required to reduce the risk of aerial hazards to 50% of avian migrants passing a given area in spring and autumn based on dynamic forecasts of migration activity. We also investigated an alternative approach, that is, employing a fixed conservation strategy based on time windows that historically capture 50% of migratory passage. In practice, during both spring and autumn, dynamic forecasts required fewer action nights compared with fixed window selection at all locations (spring: mean of 7.3 more alert days; fall: mean of 12.8 more alert days). This pattern resulted in part from the pulsed nature of bird migration captured in the radar data, where the majority (54.3%) of birds move on 10% of a migration season's nights. Our results highlight the benefits of near-term ecological forecasting and the potential advantages of dynamic mitigation strategies over static ones, especially in the face of increasing risks to migrating birds from light pollution, wind energy infrastructure, and collisions with structures.     

Assessing societal costs associated with environmental impacts

A study of “harmless” odors was utilized as a platform for determining the cost impact of envi‐ronmental effects resulting from management decisions. The cost to society of “harmless” odors eventually leads to internal costs for companies emitting the odors. It is easier to determine societal costs for “harmless” odors than to estimate the internal costs that eventually accrue to a company. However, larger societal costs will lead to larger company costs; larger societal costs prob‐ably also lead to faster company internalization of costs.c 2000 John Wiley & Sons, Inc.     

Combined effect of enzyme inducers and nitrate on selective lignin degradation in wheat straw by Ganoderma lobatum

Environmental Science and Pollution Research - Lignin is one of the main barriers to obtaining added-value products from cellulosic fraction of lignocellulosic biomass due to its random aromatic...     

Depth and muscle temperature of Pacific bluefin tuna examined with acoustic and pop-up satellite archival tags

Six Pacific bluefin tuna were tracked with ultrasonic telemetry and two with pop-up satellite archival tags (PSATs) in the eastern Pacific Ocean in 1997, 1998, and 1999. Both pressure and temperature ultrasonic transmitters were used to examine the behavior of the 2- to 4-year-old bluefin tuna. The bluefin spent over 80% of their time in the top 40 m of the water column and made occasional dives into deeper, cooler water. The mean slow-oxidative muscle temperatures of three fish instrumented with pressure and temperature transmitters were 22.0–26.1 °C in water temperatures that averaged 15.7–17.5 °C. The thermal excesses in slow-oxidative muscle averaged 6.2–8.6 °C. Variation in the temperature of the slow-oxidative muscle in the bluefin was not correlated with water temperature or swimming speeds. For comparison with the acoustic tracking data we examined the depth and ambient temperature of two Pacific bluefin tagged with pop-up satellite archival tags for 24 and 52 days. The PSAT data sets show depth and temperature distributions of the bluefin tuna similar to the acoustic data set. Swimming speeds calculated from horizontal distances with the acoustic data indicate the fish mean speeds were 1.1–1.4 fork lengths/s (FL s⁻¹). These Pacific bluefin spent the majority of their time in the top parts of the water column in the eastern Pacific Ocean in a pattern similar to that observed for yellowfin tuna. Received: 4 April 2000 / Accepted: 25 October 2000     

Stereochemistry of LinB-catalyzed biotransformation of δ-HBCD to 1R,2R,5S,6R,9R,10S-pentabromocyclododecanol

The haloalkane dehalogenase LinB from Sphingobium indicum B90A converts β-hexachlorocyclohexane (β-HCH), the most persistent HCH stereoisomer, to mono- and dihydroxylated metabolites. Recently, we reported that LinB also transforms α-, β- and γ-hexabromocyclododecanes (HBCDs), which are structurally related to HCHs. Here, we show that LinB catalyzes the hydroxylation of δ-HBCD to two pentabromocyclododecanols (PBCDOHs) and two tetrabromocyclododecadiols (TBCDDOHs). The stereochemistry of this enzymatic transformation was deduced from XRD crystal structure data of the substrate δ-HBCD and α₂-PBCDOH, one of the biotransformation products. Five stereocenters of δ-HBCD are unchanged but the one at C6 is converted to an alcohol with inversion from S- to R-configuration in a nucleophilic, S_N2-like substitution reaction. Only α₂-PBCDOH with the 1R,2R,5S,6R,9R,10S-configuration is obtained but not its enantiomer. With only two of the 64 PBCDOHs formed, these transformations indeed are regio- and stereoselective. A conformational analysis revealed that the triple-turn motive, which is predominant in δ-HBCD and in several other HBCD stereoisomers, is also found in the product. This shows that LinB preferentially converted reactive bromine atoms but not those in the conserved triple-turn motive. The widespread contamination with HCHs triggered the bacterial evolution of dehalogenases which acquired the ability to convert these pollutants and their metabolites. We here demonstrate that LinB of S. indicum also transforms HBCDs regio- and stereoselectively following a similar mechanism.     

Continuous automated imaging-in-flow cytometry for detection and early warning of Karenia brevis blooms in the Gulf of Mexico

Monitoring programs for harmful algal blooms (HABs) typically rely on time-consuming manual methods for identification and enumeration of phytoplankton, which make it difficult to obtain results with sufficient temporal resolution for early warning. Continuous automated imaging-in-flow by the Imaging FlowCytobot (IFCB) deployed at Port Aransas, TX has provided early warnings of six HAB events. Here we describe the progress in automating this early warning system for blooms of Karenia brevis. In 2009, manual inspection of IFCB images in mid-August 2009 provided early warning for a Karenia bloom that developed in mid-September. Images from 2009 were used to develop an automated classifier that was employed in 2011. Successful implementation of automated file downloading, processing and image classification allowed results to be available within 4 h after collection and to be sent to state agency representatives by email for early warning of HABs. No human illness (neurotoxic shellfish poisoning) has resulted from these events. In contrast to the common assumption that Karenia blooms are near monospecific, post-bloom analysis of the time series revealed that Karenia cells comprised at most 60–75 % of the total microplankton.     

Maternal exposure to polybrominated and polychlorinated biphenyls: infant birth weight and gestational age

Understanding the influence of maternal exposures on gestational age and birth weight is essential given that pre-term and/or low birth weight infants are at risk for increased mortality and morbidity. We performed a retrospective analysis of a cohort exposed to polybrominated biphenyls (PBB) through accidental contamination of cattle feed and polychlorinated biphenyls (PCB) through residual contamination in the geographic region. Our study population consisted of 444 mothers and their 899 infants born between 1975 and 1997. Using restricted maximum likelihood estimation, no significant association was found between estimated maternal serum PBB at conception or enrollment PCB levels and gestational age or infant birth weight in unadjusted models or in models that adjusted for maternal age, smoking, parity, infant gender, and decade of birth. For enrollment maternal serum PBB, no association was observed for gestational age. However, a negative association with high levels of enrollment maternal serum PBB and birth weight was suggested. We also examined the birth weight and gestational age among offspring of women with the highest (10%) PBB or PCB exposure, and observed no significant association. Because brominated compounds are currently used in consumer products and therefore, are increasingly prevalent in the environment, additional research is needed to better understand the potential relationship between in utero exposure to brominated compounds and adverse health outcomes.     

Place as a social space: fields of encounter relating to the local sustainability process

The paper shows how sustainability questions relate to the local space. The local place is not a static entity, but a dynamic one, undergoing constant changes, and it is the rapid social and material processes within the given local situation that is a challenge for the Chinese villages and their integrity. The following article considers the cohesion between the dwellers' emotional co-ownership of their local space and the sustainability process as a driving force in social, economic and ecological development. We bring together the classification of the seven fields of encounter, which were developed out of the empirical data of the Chinese case study villages, and sustainability oriented management considerations for all levels of this concept. We do not pretend to know the solutions, but describe a set of interrelated fields that can be anchor points for placing the solutions and show in which fields action and intervention is possible. In our concept of sustainability, every spatial field has its special meaning, needs special measures and policies and has different connotations to concepts like responsibility, family values or communication systems. We see the social sustainability process as a support for the empowerment of the local dwellers, and the SUCCESS research has encouraged the villages to find suitable sustainability oriented solutions for their natural and societal situation. Before entering the discussion about the chances and potential of a sustainability approach for the Chinese villages, it is first necessary to accept the fact that rural villages play a primordial role in Chinese society and that their potential can strengthen future pathways for China.