Insecticidal activity of raw ethanolic extracts from Magnolia dealbata Zucc on a tephritid pest

Ethanolic extracts from Magnolia dealbata (Zucc.) (Magnoliaceae); leaves, bark, seeds, sarcotesta and flowers were evaluated for insecticidal activity against adults of the Mexican fruit fly, Anastrepha ludens (Loew) (Diptera: Tephritidae). Using feeding bioassays composed from sugar-extract mixtures, only the extract from sarcotesta indicated insecticidal activity against the flies. The extracts from the other four plant tissues (leaves, bark, seeds and flowers) did not manifest any biological activity. The most effective extract was obtained from oven-dried sarcotesta, whereas extracts from fresh sarcotesta were inactive. Our results suggest that M. dealbata sarcotesta contains secondary metabolites with insecticidal activity against A. ludens adults. These metabolites are as potent as natural pyrethins and represent a potential substance for controlling this type of pest.     

Effects of the toxic dinoflagellate <Emphasis Type="Italic">Gymnodinium catenatum</Emphasis> on uptake and fate of paralytic shellfish poisons in the Pacific giant lions-paw scallop <Emphasis Type="Italic">Nodipecten subnodosus</Emphasis>

Juvenile Pacific giant lions-paw scallops Nodipecten subnodosus were fed the toxic dinoflagellate Gymnodinium catenatum, a producer of paralytic shellfish poison (PSP), supplied with Isochrysis galbana (a nontoxic microalgae). Short-term (<24 h) experiments were performed to determine clearance and ingestion rates of G. catenatum. Kinetics of PSP was examined in longer-term experiments (>2 days). At high food concentrations, juvenile scallops showed production of pseudofeces, partial shell valve closure, and reduction in feeding. According to HPLC analysis, the only toxins present in the dinoflagellate G. catenatum and in the scallops were the gonyautoxins (GTXs), except in the labial palps and digestive gland, where trace amounts of saxitoxin (STX) were present in scallops. These tissues could play an important role in toxin biotransformation. The ranking of toxin concentration in tissues was: digestive gland > labial palps > intestine > gills > mantle > adductor muscle, where the total contribution of viscera was more than 80% of the total toxin body burden. Juvenile scallops exhibited no apparent detrimental physiological responses during the long-term feeding experiment. The dinoflagellate may contribute nutrients to the scallop, in addition to the microalgae I. galbana. The dinoflagellate may enhance cell uptake and byssus production. Once PSP accumulated during the first 12 days, it was slowly eliminated. The limited capacity for accumulating toxins in the adductor muscle favors domestic marketing of scallops.     

ESTABLISHING PRIORITIES FOR WETLAND MANAGEMENT1

Wetlands provide a variety of ecological services, but are attractive sites for many development activities. Between the mid-1950's and mid-1970's about 550,000 acres, or about 0.5 percent, of the vegetated wetlands remaining in the conterminous states were converted to other uses each year. About 80 percent of these losses involved draining and clearing of inland wetlands for agricultural purposes. Recent reductions in national wetland conversion rates are due primarily to declining rates of agricultural drainage and secondarily to government programs that regulate wetlands use. Several governmental policies and programs exist that either encourage or discourage wetland conversions. Section 404 of the Clean Water Act is the major tool for Federal involvement in controlling the conversion of wetlands to other uses. The 404 program, in combination with State regulatory programs, is responsible for reducing annual conversions nationwide by about 50 percent of what is applied for, or 50,000 acres of wetlands per year, primarily through project modifications. Coastal wetlands are reasonably well protected. Inland, freshwater wetlands are generally poorly protected. Efforts to protect wetlands, given a set level of resources, could be improved by categorizing wetlands according to their relative importance and focusing existing wetland programs on high value wetlands.     

Observations on the biology of Donax trunculus and D. vittatus at Ile d'Oléron (French Atlantic coast)

Observations have been made on the biology of two species of the bivalve genus Donax, on two beaches, Vertbois and St. Trojan, on the Ile d'Oléron, French Atlantic coast. The two species displayed different vertical distribution: D. trunculus Linné in the intertidal; and D. vittatus (da Costa) between low-water spring tide (LWST) and 5 to 6m depth, with only the fringe of the population extending to the shore. D. trunculus also showed differential distribution by size or age, the youngest individuals being highest on the shore, and the oldest near LWST. The two species exhibited a similar pattern of seasonal recruitment and growth, but in both there were differences in growth characteristics between the two beaches, individuals at St. Trojan growing to a larger size than those at Vertbois. The mean pattern of mortality in the two areas was similar, and productivity per 100 recruits surviving to the first winter following settlement was greater at St. Trojan than at Vertbois. For D. trunculus the mean population density at Vertbois was higher and the production per unit area on the two beaches was similar. Production to biomass (B) and elimination to biomass (B) ratios were similar for the two beaches for both species, and while production was greater for D. trunculus at both beaches, the B and B ratios were higher for D. vittatus. Comparisons with other published data reveal that the rate of growth of D. trunculus is similar throughout its range from Brittany to the Mediterranean Sea, while that of D. vittatus shows more variation. In both species, there is a trend of increasing P/B and E/B ratios from north to south throughout the geographical range.     

Effects of zinc oxide nanoparticles on growth and antioxidant enzymes of Capsicum chinense

Abstract

The effects of suspensions of zinc oxide nanoparticles at concentrations between 100 and 500?mg L^?1 on germination of Capsicum chinense seeds and vigor of plants were evaluated using a randomized complete design with four replications, resulting in increased germination and improved development of lengths of plumule and radicle. The activities of peroxidase, catalase and ascorbate peroxidase were determined, showing that at all concentrations the activities of the former two enzymes were increased, whereas the activity of the latter was reduced at 500?mg L^?1. Pretreatments of seeds with ZnO nanoparticles can improve germination and development of seedlings and the activities of antioxidant enzymes.     

Capillary electrophoresis finger print technique (CE-SSCP): an alternative tool for the monitoring activities of HAB species in Baja California Sur Costal

In Mexican waters, there is no a formal and well-established monitoring program of harmful algal blooms (HAB) events. Until now, most of the work has been focused on the characterization of organisms present in certain communities. Therefore, the development of new techniques for the rapid detection of HAB species is necessary. Capillary electrophoresis finger print technique (CE-SSCP) is a fingerprinting technique based on the identification of different conformers dependent of its base composition. This technique, coupled with capillary electrophoresis, has been used to compare and identify different conformers. The aim of this study was to determine if CE-SSCP analysis of ribosomal RNA (rRNA) gene fragments could be used for a rapid identification of toxic and harmful HAB species to improve monitoring activities along the coasts of Baja California Sur, Mexico.Three different highly variable regions of the 18S and 28S rRNA genes were chosen and their suitability for the discrimination of different dinoflagellate species was assessed by CE-SSCP.The CE-SSCP results obtained for the LSU D7 fragment has demonstrated that this technique with this gene region could be useful for the identification of the ten dinoflagellates species of different genera.We have shown that this method can be used to discriminate species and the next step will be to apply it to natural samples to achieve our goal of molecular monitoring for toxic algae in Mexican waters. This strategy will offer an option to improve an early warning system of HAB events for coastal BCS, allowing the possible implementation of mitigation strategies. A monitoring program of HAB species using molecular methods will permit the analysis of several samples in a short period of time, without the pressure of counting with a taxonomic expert in phytoplankton taxonomy.     

Mechanical,Barrier and Antioxidant Properties of Chitosan Films Incorporating Cinnamaldehyde

Chitosan films (CF) [1 and 2% w/v] alone and with cinnamaldehyde (CNE) [0.25, 0.5 and 1% v/v] were prepared using an emulsion method, and the obtained films were characterized in terms of water vapor permeability (WVP), water solubility and optical, mechanical and antioxidant properties. The incorporation of CNE at 1% (v/v) significantly decreased the water solubility of the film by approximately 4% for the 1 and 2% CF films, whereas the WVP increased (2.5–3.5 times). The incorporation of CNE (0.25 and 0.5%) into 2% CF significantly increased the tensile strength (TS) (62 and 34%, respectively) and the percent elongation (%E) values, 26, 30 and 52% for CF that contained 0.25, 0.5 and 1% CNE, respectively. The largest value of the elasticity modulus (EM) was observed for 2% CF with 0.25% CNE. All films exhibited a yellow appearance (b*), but the CNE content had a marked impact on the coloration of the films. The CNE recoveries of the CF films (1 and 2%) with 1% of CNE were high (43 and 67%). The antioxidant activities indicated that the incorporation of 1% CNE into CF films (1 and 2%) increased the antioxidant activity. The protective effects of the films with and without CNE on erythrocytes were very strong (36–72% hemolysis inhibition). These results suggest there are potential applications for CF-CNE films as active packaging for the preservation of food products.     

Butyltin Compounds in Sediments of the Bahía Blanca Estuary, Argentina

Systematic measurements of both Tributyltin (TBT) and Dibutyltin (DBT) in sediments along different locations in the inner zone of Bahía Blanca estuary were done. Two samples were taken near the main dry dock facility, at Puerto Belgrano naval base, in Argentina. TBT concentrations from non-detected to 170.3 ng Sn g⁻¹ were measured in the inner region of the estuary, and higher one of 3,288 ng Sn g⁻¹ near the dry dock at Puerto Belgrano. DBT values ranging between non-detected and 75.2 ng Sn g⁻¹ were obtained along the principal channel, but extreme concentration of 1,645 ng Sn g⁻¹ was measured at Puerto Belgrano. These values show that this estuary is affected by organotin pollution, mainly in areas of heavy shipyard activities.     

How economics can further the success of ecological restoration

Restoration scientists and practitioners have recently begun to include economic and social aspects in the design and investment decisions for restoration projects. With few exceptions, ecological restoration studies that include economics focus solely on evaluating costs of restoration projects. However, economic principles, tools, and instruments can be applied to a range of other factors that affect project success. We considered the relevance of applying economics to address 4 key challenges of ecological restoration: assessing social and economic benefits, estimating overall costs, project prioritization and selection, and long‐term financing of restoration programs. We found it is uncommon to consider all types of benefits (such as nonmarket values) and costs (such as transaction costs) in restoration programs. Total benefit of a restoration project can be estimated using market prices and various nonmarket valuation techniques. Total cost of a project can be estimated using methods based on property or land‐sale prices, such as hedonic pricing method and organizational surveys. Securing continuous (or long‐term) funding is also vital to accomplishing restoration goals and can be achieved by establishing synergy with existing programs, public–private partnerships, and financing through taxation.     

Prenatal diagnosis of thrombocytopenia absent radius syndrome using ultrasound and fetoscopy

The prenatal diagnosis of thrombocytopenia absent radius syndrome in both dizygotic twins utilizing ultrasound, radiography and fetoscopy is described.