6,772 research outputs found
Reconciling opposing views on carbon cycling in the coastal ocean: continental shelves as sinks and near-shore ecosystems as sources of atmospheric CO2
Despite their moderately-sized surface area, continental marginal seas play a significant role in the biogeochemical cycles of carbon, as they receive huge amounts of upwelled and riverine inputs of carbon and nutrients, sustaining a disproportionate large biological activity compared to their relative surface area. A synthesis of worldwide measurements of the partial pressure of CO2 (pCO2) indicates that most open shelves in the temperate and high latitude regions are under-saturated with respect to atmospheric CO2 during all seasons, although the low latitude shelves seem to be over-saturated. Most inner estuaries and near-shore coastal areas on the other hand are over-saturated with respect to atmospheric CO2. The scaling of air-sea CO2 fluxes based on pCO2 measurements and carbon mass balance calculations indicate that the continental shelves absorb atmospheric CO2 ranging between 0.33 to 0.36 Pg C yr-1 that corresponds to an additional sink of 27% to ~30% of the CO2 uptake by the open oceans based on the most recent pCO2 climatology (Takahashi et al., 2008; Deep-Sea Research II, this issue). Inner estuaries, salt marshes and mangroves emit up to 0.50 Pg C yr-1, although these estimates are prone to large uncertainty due to poorly constrained ecosystem surface area estimates. Nevertheless, the view of continental shelves as sinks and near-shore ecosystems as sources of atmospheric CO2 allows reconciling long-lived opposing views on carbon cycling in the coastal ocean
Behavioral and cardiopulmonary effects of dexmedetomidine alone and in combination with butorphanol, methadone, morphine or tramadol in conscious sheep
Objective:
To compare cardiopulmonary and sedative effects following administration of dexmedetomidine alone or with butorphanol, methadone, morphine or tramadol in healthy sheep.
Study design:
Randomized crossover study.
Animals:
Six Santa Inês sheep, five females, one male, aged 12–28 months and weighing 40.1 ± 6.2 kg.
Methods:
Sheep were assigned treatments of dexmedetomidine (0.005 mg kg−1; D); D and butorphanol (0.15 mg kg−1; DB); D and methadone (0.5 mg kg−1; DM); D and morphine (0.5 mg kg−1; DMO); or D and tramadol (5.0 mg kg−1; DT). All drugs were administered intravenously with at least 7 days between each treatment. Rectal temperature, heart rate (HR), respiratory rate (fR), invasive arterial pressure, blood gases and electrolytes were measured prior to administration of drugs (baseline, T0) and every 15 minutes following drug administration for 120 minutes (T15–T120). Sedation was scored by three observers blinded to treatment.
Results:
HR decreased in all treatments and fR decreased in DM at T30 and DMO at T30 and T45. PaCO2 was increased in D, DB and DM compared with baseline, and PaO2 decreased in D at T15 and T45; in DB at T15 to T75; in DM at T15 to T60; in DMO at T15; and in DT at T15, T30 and T75. There was a decrease in temperature in D, DB and DM. An increased pH was measured in D at all time points and in DT at T30–T120. inline image and base excess were increased in all treatments compared with baseline. There were no statistical differences in sedation scores.
Conclusions and clinical relevance:
The combination of dexmedetomidine with butorphanol, methadone, morphine or tramadol resulted in similar changes in cardiopulmonary function and did not improve sedation when compared with dexmedetomidine alone
Wood consumption and pellet production by Azorean Kalotermitidae: Kalotermes flavicollis and Cryptotermes brevis
Existem nos Açores duas espécies de térmitas da família Kalotermitidae: a Kalotermes flavicollis é uma térmita de madeira verde e é uma praga urbana menor. A Cryptotermes brevis é uma térmita de madeira seca e é uma importante praga para mobiliário e estruturas. São analisadas as espécies de madeira consumidas por cada espécie nos Açores sendo descritas diferenças na cor, tamanho, forma, e modo de despejo das partículas fecais. A taxa de consumo de madeira e a produção de partículas fecais para a espécie Cryptotermes brevis foram estudadas em 49 tipos diferentes de madeiras. Verificou-se que duas espécies de madeira produzidas localmente e muito usadas na construção, Cryptomeria japonica e Eucalyptus sp., foram das mais consumidas, indicando a importância do desenvolvimento de um sistema local para tratamento por pressão em autoclave das madeiras. Entre as madeiras menos consumidas (mais resistentes) encontram-se espécies tropicais, como o Jatobá e a Maçaranduba. As partículas fecais que são expulsas das galerias pelas térmitas são a forma mais conspícua de detectar infestações por Cryptotermes brevis, dando bons meios para monitorizar a localização de térmitas, o tamanho da colónia e a sua actividade. Foi verificado que a expulsão de partículas fecais é descontínua. Contudo, alguns períodos de expulsão de partículas fecais são contínuos por alguns dias, com taxas de expulsões de 274 partículas fecais, por hora, com acumulações de até 7,8 gramas num período de duas semanas.ABSTRACT: Two termite species of the family Kalotermitidae occur in the Azores: Kalotermes flavicollis is a dampwood termite and minor house pest. Cryptotermes brevis is a dry wood termite and a major pest of furniture and structures. Records of wood species consumed by each species in the Azores are reviewed. Differences in the color, size, shape, disposal of fecal pellets of each species are described. Rates of wood consumption, pellet production were experimentally studied for Cryptotermes brevis on 49 different wood species. Two wood species that are locally produced and widely utilized for construction, Cryptomeria japonica and Eucalyptus sp., were found to be among the most preferred woods for termite consumption indicating an important need for the development of an effective local pressure treatment system for preserving these woods. Least preferred (most resistant woods) included tropical hardwood species such as Jatobá and Maçaranduba. Fecal pellets expelled from galleries by termites are the most conspicuous evidence of Cryptotermes brevis infestations and provide a potential means of monitoring termite location, colony size and activity. Pellet expulsion was found to be discontinuous. However some bouts of pellet dumping were observed to be continuous for at least several days with rates of pellet expulsion of up to 274 pellets per hour, with pellet accumulations of as much as 7.8 grams over a two-week period
Treatment of Cryptotermes brevis infestations in furniture with heat, solid fumigants and inert gases
A Cryptotermes brevis é uma térmita extraordinária na sua capacidade única de atacar madeira extremamente seca. É, igualmente, extraordinária na capacidade de atacar uma grande variedade de tipos de madeira, o que nos leva a concluir como sendo a única espécie de térmitas que é facilmente encontrada em mobílias. Como tal, é muito fácil a sua dispersão aquando do transporte de mobílias infestadas, de lugar para lugar, e esta é uma das principais razões pela qual esta térmita consegue ter uma distribuição tão ampla em áreas urbanas, em praticamente todo mundo. É muito provável que a sua introdução nos Açores tenha sido através de mobília infestada e que a dispersão contínua que se tem verificado de cidade para cidade seja devido a essa razão. Ou seja, o tratamento de mobílias é uma componente importante de um programa integrado para lidar com o controlo e contenção desta espécie de térmita. O objectivo deste trabalho é apresentar os resultados obtidos de três tipos de experiências para tratamento de mobílias infestadas com a Cryptotermis brevis. A primeira experiência consistiu num método muito simples, envolvendo o selar de um objecto infestado dentro de um saco de plástico preto, sendo este colocado num local fora do laboratório, a fim de se encontrar em plena exposição solar durante o mês de Agosto. O método seguinte consistiu em selar um objecto infestado num recipiente com um de três tipos de fumigantes sólidos: bolas de naftalina, para-dichlorobenzeno ou dichlorvos (Vapona®). O último método envolveu um teste de anóxia, em que um de três tipos de gases inertes, azoto (N2), dióxido de carbono (CO2) ou árgon (Ar), foi usado para substituir o ar existente dentro de um saco plástico (bolha) selado, contendo um objecto infestado.ABSTRACT: Cryptotermis brevis is an extraordinary termite in its unique ability to attack extremely dry wood. It is also unique in its ability to attack a wide variety of wood species. This leads to it being one of the only termites in the world which is commonly found attacking furniture. As such, it is easily moved when people move their furniture from place to place and this is one of the reasons why this termite has become widely dispersed to urban areas around the world. It is very likely it was first introduced into the Azores with furniture and that its continued dispersal from island to island and town to town will be by the further movement of infested furniture. Therefore furniture treatment is an important component of an integrated program for dealing with the control and containment of this pest species. The objective of this presentation is to explain the results of three types of experimental furniture treatment that we conducted. The first of these was a simple method involving the sealing of an infested item inside a black plastic bag which was then placed in full sun exposure outdoors during the month of August. The next method involved sealing an infested item in a container with one of three solid fumigants: naphthalene (moth balls), para-dichlorobenzene (PDB moth balls), or dichlorvos (Vapona®). The final method involved anoxia test in which one of three inert gases, either nitrogen (N2), carbon dioxide (CO2), or argon (Air) gases were used to displace the air in a sealed bag holding an infested item
Flight and colony foundation of Azorean termites with emphasis on Cryptotermes brevis
Cada uma das três espécies de térmitas existentes no arquipélago açoriano apresenta um comportamento de voo em momentos distintos ao longo do dia e ao longo do ano. A Cryptotermes brevis tem o seu período de dispersão (de voo) entre os meses de Junho e Agosto no crepúsculo vespertino, a Kalotermes flavicollis de Setembro a Outubro, durante a tarde, e a Reticulitermes grassei tem o seu período de enxameamento na Primavera, durante a manhã. Das espécies referidas, a que apresenta maior importância, por constituir uma praga de dimensões consideráveis em algumas das ilhas, é a C. brevis, a única que tem um comportamento de voo nocturno, tornando, assim, possível o uso de armadilhas luminosas. As experiências aqui apresentadas contêm vários testes com diferentes tipos de luzes, fluorescentes e incandescentes, diferentes cores de armadilhas pegajosas, bem como diferentes tipos de colas e fitas colantes. Após o período de voo, as térmitas exibem uma sequência de comportamentos que foram observados e analisados. Foi estudado o tempo para cada um dos seguintes padrões de comportamento: libertação das asas, comportamento de procura (de um parceiro), formação de pares, selagem da câmara de reprodução (ou ninho), amputação das antenas, início da deposição de ovos e tempo até à primeira eclosão. A preferência por buracos de diferentes diâmetros e diferentes espécies de madeira foi também estudada, assim como a produção de ovos e as taxas de sobrevivência e de produção dos mesmos.ABSTRACT: Each of the three Azorean termite species flies during a different season and different time of the day. Cryptotermes brevis flies from June to August, at dusk; Kalotermes flavicollis flies from September to October, in the afternoon; and Reticulitermes grassei flies during the spring, probably during the morning hours. C. brevis is the most important pest and the only one that flies at night, therefore light trapping is possible. Experiments were conducted with fluorescent and incandescent lights, different colours of sticky traps and different kinds of glue or tape. Following the dispersal flight, the termite exhibits a sequence of behaviours which were observed and analysed. The timing of the follow behavioural events was studied: de-alation, searching behaviour, tandem running, sealing the copulation, de-antennation, commencement of oviposition and time to first hatch. Hole size and wood species preferences for colony establishment were also investigated. In addition, egg production and colony survival rates on different woods were studied
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Crossing Symmetry Violation of Unitarized Pion-Pion Amplitude in the Resonance Region
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Phylogeny, biogeography and ecology of azorean termites
Three species of termites are currently known in the archipelago (the European dampwood termite, Kalotermes flavicollis, the West Indies drywood termite, Cryptotermes brevis, and the Iberian subterranean termite Reticulitermes grassei). All these three species are "lower termites", that is, primitive species having simple galleries but not well formed nests, tending to be less socially advanced and to occur in more temperate latitudes, generally eating only wood but not other types of cellulose, and all having flagellates in the gut. Kalotermes flavicollis is native to most of the Mediterranean region and was probably introduced in the islands many decades ago through vineyard or orchard stocks. In Terceira Island, K. flavicollis is common in the heartwood of several trees and shrubs along the coast. Its colony members may exceed 1000 but the average colony has 600. This termite has been considered as a minor structural pest in a few houses, but structural infestations by this species only occur in association with moisture due to leaks or condensation. Cryptotermes brevis is the most destructive drywood termite pest in the world. Due to its exceptional ability to withstand wood with low moisture content it is able to attack all kinds of dead and dry wood with a strong preference for sapwood over heartwood. It attacks wood in service including structural timbers, beams, studs, rafters, cladding, flooring, molding, doors, window frames and wooden articles such as carvings, tools, picture frames, musical instruments, looms, bed posts, and almost all forms of wood. Serious infestations of this termite are currently known in São Miguel, Terceira, Faial and Santa Maria Islands. Local research has shown that colony size may range up to about 300 but that average colony size is only 45 individuals. Severe damage results not from individual colonies but from high levels of reinfestation leading to the establishment of large numbers of colonies. Successful colony foundation by this termite is promoted by the widespread occurrence of several anobiid beetles whose exit holes in wood provide ideal entrance holes for termite alates. Reticulitermes grassei, a subterranean termite, has only been found in the Azores Archipelago, in the Horta city (Faial Island) where it has been causing severe damage to a few buildings. Reticulitermes colonies may grow to millions of individuals promoted by numerous nymphoid reproductive’s which develop within colonies. Unlike the other two species, colonies of Reticulitermes may spread by tunnelling through the ground
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