Natural abundance of stable carbon and nitrogen isotopes in Cannabis sativa reflects growth conditions

Stable carbon and nitrogen isotope signatures (delta C-13 and delta N-15) of Cannabis sativa were assessed for their usefulness to trace seized Cannabis leaves to the country of origin and to source crops by determining how isotope signatures relate to plant growth conditions. The isotopic composition of Cannabis examined here covered nearly the entire range of values reported for terrestrial C-3 plants. The delta C-13 values of Cannabis from Australia, Papua New Guinea and Thailand ranged from -36 to -25 parts per thousand, and delta N-15 values ranged from -1.0 to 15.8 parts per thousand. The stable isotope content did not allow differentiation between Cannabis originating from the three countries, but delta C-13 values of plantation-grown Cannabis differed between well-watered plants (average delta C-13 of -30.0 parts per thousand) and plants that had received little irrigation (average delta C-13 of -26.4 parts per thousand). Cannabis grown under controlled conditions had delta C-13 values of -32.6 and -30.6 parts per thousand with high and low water supply, respectively. These results indicate that water availability determines leaf C-13 in plants grown under similar conditions of light, temperature and air humidity. The delta C-13 values also distinguished between indoor- and outdoor-grown Cannabis; indoor- grown plants had overall more negative delta C-13 values (average -31.8 parts per thousand) than outdoor-grown plants (average -27.9 parts per thousand). Contributing to the strong C-13-depletion of indoor- grown plants may be high relative humidity, poor ventilation and recycling of C-13-depleted respired CO2. Mineral fertilizers had mostly lower delta N-15 values (-0.2 to 2.2 parts per thousand) than manure-based fertilizers (7.6 to 22.7 parts per thousand). It was possible to link delta N-15 values of fertilizers associated with a crop site to soil and plant delta N-15 values. The strong relationship between soil, fertilizer, and plant delta N-15 suggests that Cannabis delta N-15 is determined by the isotopic composition of the nitrogen source. The distinct delta N-15 values measured in Cannabis crops make delta N-15 an excellent tool for matching seized Cannabis with a source crop. A case study is presented that demonstrates how delta C-13 and delta N-15 values can be used as a forensic tool.

Diving behaviour of two Australian bimodally respiring turtles, Rheodytes leukops and Emydura macquarii, in a natural setting

Time-depth recorders were used to investigate the diving performance and behaviour of two bimodally respiring turtle species, Rheodytes leukops and Emydura niacquarii, known to have a high and low reliance on aquatic respiration, respectively. Significant differences in diving performance between R. leukops and E. macquarii were observed in the number of dives/day (39.3 +/- 5.38 vs 112.2 +/- 11.73 dives/day; mean +/- SE), mean dive length (33.1 +/- 7.33 min vs 9.6 +/- 2.26 min) and maximum dive length (623 +/- 104.74 min vs 67.1 +/- 8.14 min), respectively. Differences in diving performance between R. leukops and E macquarii are attributed to the species' reliance (or lack thereof) upon aquatic respiration. Rheodytes leukops displayed a weak bimodal pattern of increased surfacing frequency in the early morning (05:00-07:00) and late afternoon (14:00-18:00), while E. macquarii displayed a strong bimodal pattern of elevated surfacing frequency over similar time periods. Daily patterns of increased surfacing frequency for both species failed to correlate with fluctuating aquatic Po-2 levels or water temperature, and may instead be explained by the heightened activity levels of both species during twilight.

Geographic variation of natural products of tropical nudibranch Asteronotus cespitosus

Extracts of the dorid nudibranch Asteronotus cespitosus from two geographically separate regions of Australia and from the Philippines were compared using thin-layer, high-performance liquid and gas chromatography and H-1 NMR analysis. Halogenated metabolites were detected in all mollusk specimens. The major component detected in digestive tissue of specimens from the Great Barrier Reef in northeastern Australia was 4,6-dibromo2-(2',4'-dibromophenoxy)phenol (1), with minor amounts of 3,5-dibromo-2(3',5'-dibromo-20-methoxyphenoxy)phenol (2). In a specimen collected from northwestern Australia, only 3,5-dibromo-2-(3',5'-dibromo-2'-methoxyphenoxy)phenol was found. The specimen from the Philippines contained 2,3,4,5-tetrabromo-6-(2'-bromophenoxy) phenol (3) together with a novel chlorinated pyrrolidone (4). In addition, the sesquiterpenes dehydroherbadysidolide (5) and spirodysin (6) were detected in the digestive organs and mantle tissue of the nudibranchs from the Great Barrier Reef and from the Philippines, whereas these chemicals were not found in the specimen from northwestern Australia. All of the chemicals (1-3,5, and 6) have previously been isolated from the sponge Dysidea herbacea, as have chlorinated metabolites related to 4. This is the first time the characteristic halogenated metabolites that typify Dysidea herbacea have been reported from a carnivorous mollusk, which implies a dietary origin as opposed to de novo synthesis.

Cloud-point extraction and preconcentration of cyanobacterial toxins (microcystins) from natural waters using a cationic surfactant

A new cloud-point extraction and preconcentration method, using a cationic, surfactant, Aliquat-336 (tricaprylyl-methy;ammonium chloride), his-been developed for the determination of cyanobacterial toxins, microcystins, in natural waters. Sodium sulfate was used to induce phase separation at 25 degreesC. The phase behavior of Aliquat-336 with respect to concentration of Na2SO4 was studied. The cloud-point system revealed a very high phase volume ratio compared to other established systems of nonionic, anionic, and cationic surfactants: At pH 6-7, it showed an outstanding selectivity in ahalyte extraction for anionic species. Only MC-LR and MC-YR, which are known to be predominantly anionic, were extracted (with averaged recoveries of 113.9 +/- 9% and 87.1 +/- 7%, respectively). MC-RR, which is likely to be amphoteric at the above pH range, was. not cle tectable in.the extract. Coupled to HPLC/UV separation and detection, the cloud-point extraction method (with 2.5 mM Aliquat-336 and 75 mM Na2SO4 at 25 degreesC) offered detection limits of 150 +/- 7 and 470 +/- 72 pg/mL for MC-LR and MC-YR, respectively, in 25 mL of deionized water. Repeatability of the method was 7.6% for MC-LR and 7.3% for MC-YR: The cloud-point extraction process can be. completed within 10-15 min with no cleanup steps required. Applicability of the new method to the determination of microcystins in real samples was demonstrated using natural surface waters, collected from a local river and a local duck pond spiked with realistic. concentrations of microcystins. Effects of salinity and organic matter (TOC) content in the water sample on the extraction efficiency were also studied.

Seasonal changes in the diving performance of the bimodally respiring freshwater turtle Rheodytes leukops in a natural setting

The objective of this study was to investigate how seasonally fluctuating environmental conditions influence the diving performance of the highly aquatic, bimodally respiring turtle Rheodytes leukops in a natural setting. Over four consecutive seasons (Austral autumn 2000 to summer 2001), the diving behaviour of adult turtles was recorded via pressure-sensitive time-depth recorders within Marlborough Creek, central Queensland, Australia. Short surfacing intervals recorded for R. leukops in winter suggest that the species utilizes aquatic respiration as an overwintering strategy to prevent the development of a metabolic acidosis during the long inactive dives observed during the season. As water temperature increases and aquatic P-O 2 decreases, R. leukops switches from facultative to obligate air-breathing, presumably because of the increased metabolic cost associated with aquatic respiration under summer conditions. Increases in mean surfacing time from winter to spring and summer are attributed to seasonal changes in behaviour possibly associated with foraging rather than to the physiological state of the turtle, given that no difference in median surfacing time among seasons was observed.

A global health problem caused by arsenic from natural sources

Arsenic is a carcinogen to both humans and animals. Arsenicals have been associated with cancers of the skin, lung, and bladder. Clinical manifestations of chronic arsenic poisoning include non-cancer end point of hyper- and hypo-pigmentation, keratosis, hypertension, cardiovascular diseases and diabetes. Epidemiological evidence indicates that arsenic concentration exceeding 50 mug l(-1) in the drinking water is not public health protective. The current WHO recommended guideline value for arsenic in drinking water is 10 mug l(-1), whereas many developing countries are still having a value of 50 mug 1(-1). It has been estimated that tens of millions of people are. at risk exposing to excessive levels of arsenic from both contaminated water and arsenic-bearing coal from natural sources. The global health implication and possible intervention strategies were also discussed in this review article. (C) 2003 Elsevier Ltd. All rights reserved.

Determination of total petroleum hydrocarbons in soil from different locations using infrared spectrophotometry and gas chromatography

Total petroleum hydrocarbons (TPH) are important environmental contaminants which are toxic to human and environmental receptors. Several analytical methods have been used to quantify TPH levels in contaminated soils, specifically through infrared spectrometry (IR) and gas chromatography (GC). Despite being two of the most used techniques, some issues remain that have been inadequately studied: a) applicability of both techniques to soils contaminated with two distinct types of fuel (petrol and diesel), b) influence of the soil natural organic matter content on the results achieved by various analytical methods, and c) evaluation of the performance of both techniques in analyses of soils with different levels of contamination (presumably non-contaminated and potentially contaminated). The main objectives of this work were to answer these questions and to provide more complete information about the potentials and limitations of GC and IR techniques. The results led us to the following conclusions: a) IR analysis of soils contaminated with petrol is not suitable due to volatilisation losses, b) there is a significant influence of organic matter in IR analysis, and c) both techniques demonstrated the capacity to accurately quantify TPH in soils, irrespective of their contamination levels.

Gest��o de instala����es el��ctricas para optimiza����o do desempenho, efici��ncia e qualidade de energia em grandes edif��cios com integra����o de Miniprodu����o

As altera����es clim��ticas e as emiss��es de CO2 s��o quest��es que suscitam a n��vel internacional e nacional o desenvolvimento de estrat��gias que atenuem os seus impactes. A Efici��ncia Energ��tica (EE) �� essencial para que num futuro pr��ximo n��o haja impactes significativos no meio ambiente devido a elevado e ineficiente consumo energ��tico. A Uni��o Europeia (UE) e Portugal t��m desenvolvido pol��ticas e programas que estimulam a efici��ncia energ��tica, bem como a diminui����o de gases com efeito de estufa (GEE) e a promo����o da utiliza����o de fontes de energia renov��vel. Por outro lado vivemos numa sociedade que passa cerca de 80% do seu tempo em edif��cios e, nestes, �� consumida 40% da energia mundial. Com uma depend��ncia energ��tica superior a 80%, Portugal tem vindo a apostar, nos ��ltimos anos, em fontes de energia renov��vel. Esta aposta serve como substitui����o de fontes, mas n��o leva directamente �� redu����o de consumos. A redu����o da factura de energia s�� pode ser atingida com uma maior efici��ncia energ��tica e melhores pr��ticas de gest��o de energia em edif��cios, transportes e industria. Esta disserta����o centra-se especificamente num conjunto de edif��cios p��blicos, patrim��nio municipal da autarquia de Matosinhos, cujo modelo de fornecimento da energia el��ctrica �� pass��vel de an��lise cr��tica no sentido de uma optimiza����o radical ao n��vel da concep����o da rede e explora����o, com consequente redu����o de custos ao n��vel da factura����o. Esta nova metodologia de explora����o e gest��o de sistemas el��ctricos incidir�� na cria����o de um ���campus��� energ��tico aut��rquico resultante do novo layout da rede e respectivo fornecimento de energia a partir da rede de distribui����o p��blica. O estudo permitir�� fornecer ferramentas fundamentais para a gest��o municipal e empresarial ao n��vel da sustentabilidade energ��tica nos edif��cios p��blicos com abrang��ncia aos servi��os empresariais. De referir que a gest��o das instala����es el��ctricas para optimiza����o do desempenho, efici��ncia e qualidade de energia �� aplic��vel aos 308 munic��pios nacionais com relev��ncia para as empresas que apresentam consumos significativos nos seus edif��cios. Enquanto funcion��rio da C��mara Municipal de Matosinhos, este munic��pio foi uma escolha natural como refer��ncia, na an��lise da rela����o existente entre a administra����o local e a gest��o da energia. Para ajudar �� an��lise foi efectuado um benchmarketing a cinco edif��cios municipais: Edif��cio dos Pa��os do Concelho, Biblioteca Municipal Florbela Espanca, Palacete Visconde Trev��es, ex-Edif��cio dos SMAS e Edif��cio do ex-Tribunal, visando potenciar a correcta gest��o de energia destes edif��cios por parte das entidades que os gerem, perante novas oportunidades de melhoria e solu����es encontradas. Como contributo ��s metas impostas pela Directiva 2009/28/CE para 2020, a qual prev�� uma redu����o de 20% no consumo final de energia atrav��s da efici��ncia energ��tica, a incorpora����o de 20% de energia renov��vel no consumo energ��tico global e a consequente redu����o em 20% da emiss��o de GEE, �� apresentado um estudo ao n��vel de um parque fotovoltaico com a componente t��cnica e econ��mica.

Gas emissions on rice culture and its importance on air quality

Disserta����o para obten����o do Grau de Mestre em Engenharia do Ambiente Perfil Gest��o de Sistemas Ambientais

Development of a "green process" for the isolation of natural functional extracts with anti-cancer activity - Application of high-pressure technology

Disserta����o para obten����o do Grau de Mestre em Engenharia Qu��mica e Bioqu��mica

Isolation and encapsulation of a natural colourant using green technologies

The use of natural pigments instead of synthetic colourants is receiving growing interest in the food industry. In this field, cactus pears (Opuntia spp.) have been identified to be a promising betalainic crops covering a wide coloured spectrum. The aim of this work was to develop adequate clean and mild methodologies for the isolation and encapsulation of betacyanins, from cactus pear fruits (Opuntia spp.). Firstly, two different emerging technologies, namely PLE (Pressurized Liquid Extraction) and HPCDAE (High Pressure Carbon Dioxide-Assisted Extraction), were exploited to isolation of betacyanins form cactus pear fruits. Different process conditions were tested for the maximum recovery of betacyanins. Results showed that highest extraction yields were achieved for HPCDAE and mass ratio of pressurized carbon dioxide vs. acidified water was the parameter that most affected the betacyanins extraction. At optimum conditions of HPCDAE, Opuntia spp. extract presented a total betacyanin content of 211 �� 10 mg/100 g whereas extracts obtained using conventional extraction, PLE in static and in dynamic mode presented a total betacyanin content of 85 �� 3, 191 �� 2 and 153 �� 5 mg/100 g, respectively. HPCDAE has proven to be a successful technology to extract betacyanins from Opuntia spp. fruits. Afterward, Supercritical Fluid Technology was exploited to develop lipidic particles of betalain-rich extract. A betacyanin-rich conventional extract was encapsulated by PGSS�� (Particles from Gas Saturated Solutions) technique. Different process conditions were tested in order to model the encapsulation of betacyanins. The pressure had a negative effect on betacyanin encapsulation. Lower pressures leads to an increase in the betacyanin encapsulation. This effect was more pronounced at higher temperatures and lower equilibrium time. At these conditions, Opuntia spp. particles presented 64.4 �� 4.5 mg/100 g and high antioxidant capacity. When compared with the Opuntia spp. dried extract, lipidic particles contributed to a better homogenization of the pink colour after incorporation in ice cream.

Study on the degradation of natural fiber geotextiles

Current societal challenges increasingly demand the need to seek for efficient and sustainable solutions to daily problems. Construction, as a result of its activity, is one of the main responsible industry for the exploitation of resources and greenhouse gas emissions. In this way, several research works are being undertaken to change some of the current practices. This paper presents the work being done at University of Minho to study de degradation of natural fibers when used as a sustainable solution for soil reinforcement. Jute and sisal fibrous structures (0��/90��) were studied in terms of their degradation over time, when incorporated into soil and when subject to accelerated aging tests in a QUV weathering test equipment. Results show that the process of biodegradation of natural fibers is clearly accelerated by the action of temperature, moisture and solar radiation, explaining further degradation of jute and sisal fibers when exposed to these factors, although more pronounced in jute fabric structures.

Sequencing lifeline repairs after an earthquake: an economic approach

Recoveries after recent earthquakes in the U.S. and Japan have shown that large welfare gains can be achieved by reshaping current emergency plans as incentive-compatible contracts. We apply tools from the mechanisms design literature to show ways to integrate economic incentives into the management of natural disasters and discuss issues related to the application to seismic event recovery. The focus is on restoring lifeline services such as the water, gas, transportation, and electric power networks. We put forward decisional procedures that an uninformed planner could employ to set repair priorities and help to coordinate lifeline firms in the post-earthquake reconstruction.

Landscape context on generalist and specialist aphid natural enemies

Report for the scientific sojourn at the University of Lund, Sweden, between May and September 2007. A landscape-scale research approach has been highlighted by a growing body of literature as essential for understanding important ecosystem services as biological control. Aphids are victims of a diversity of enemies making the aphid-enemy interaction a nice example for the role of enemy diversity for the functioning of biological control. Here it is examined the effects of landscape complexity on cereal aphids and associated natural enemies that varied in the degree of specialization. Parasitoids wasps abundance did not differ between landscape types but was strongly negatively related to the percentage of arable land. In contrast, abundances of generalist predators like Coccinellidae were significantly higher in simple landscapes since can benefit from the high availability of a variety of alternative resources within cropping systems. Consequently coccinellidae-to-aphid ratio was significantly higher in fields in homogenous landscapes as compared to fields included in an heterogeneous landscape, suggesting that enemy pressure on cereal aphids increases with landscape simplification. The landscape effect will depend mainly on the degree of specialization of functionally dominant natural enemies, so that the results imply that conservation actions aiming to optimise abundance for one taxonomic group in the agricultural landscape will not automatically increase abundance of other groups. Given that the strength of natural enemy impact on biocontrol depends on landscape features and the role of functionally dominant natural enemies. So, therefore it is essential to focus the future empirical work in examining the schedule of agricultural landscapes that maintain a diversity of generalist and specialist natural enemies.

Proyecto ecotur��stico integrado en la Reserva Natural El Tisey - La Estanzuela

El presente proyecto realizado en la Reserva Natural El Tisey-La Estanzuela en la Rep��blica de Nicaragua pretende mejorar la situaci��n de dicha Reserva como destino ecotur��stico. Mediante una descripci��n exhaustiva del ��rea y una valoraci��n de los recursos y servicios tur��sticos, se ha planteado la problem��tica para el desarrollo del ecoturismo. Seg��n la OMT, el ecoturismo es un tipo de turismo sostenible que se realiza en espacios naturales protegidos para conocer la flora y fauna caracter��sticas. Debe satisfacer las necesidades de los turistas y de los aut��ctonos, al mismo tiempo que protege y mejora las oportunidades de futuro y se respeta la integridad cultural, los procesos ecol��gicos, la diversidad biol��gica y los sistemas de apoyo a la vida. En base a ��sto y a los resultados obtenidos tanto de la valoraci��n de los servicios y recursos como del an��lisis DAFO, se han propuesto un conjunto de mejoras y se ha realizado un plan de actuaci��n, que se trata de la elaboraci��n de cuatro itinerarios as�� como de tr��pticos informativos, que de llevarse a cabo, mejorar��an las condiciones tur��sticas y de seguro que aumentar��a la afluencia de turistas.