In this paper we describe a cryopreservation protocol followed by the culture of Symbiodinium sp. isolated from the Caribbean gorgonian Pseudopterogorgia elisabethae as a potential renewable source of the dinoflagellate symbiont. Four different freezing protocols were designed: a controlled
cooling device designed to cool at 1°C/min, a three-step protocol (−20°C for 2 h, −70°C for 2 h, liquid nitrogen-LN2), a two-step protocol (−70°C for 2 h, LN2), and a one-step protocol (LN2). All cells were stored in LN2 after cryopreservation. The cryoprotective agents (CPA) used were ethanol (EtOH) and methanol (MeOH) at 10 and 20%, and seawater
(FSW) was used as a control. Viability measurements using cell counts showed that all cryopreservation protocols were relatively
successful, and no trends were observed regarding freezing protocol or CPA used. After 19 weeks in culture the viability of
samples which had high biomass was determined by the fluorescent assay CellTiter Blue™. The most viable cultures were those
cryopreserved by a two-step protocol using 20% MeOH or 20% EtOH as a CPA. A genetic examination of the DNA of these samples
using Symbiodinium-specific PCR primers confirmed that the composition of the culture had not changed. For the first time, we report that Symbiodinium sp. isolated from a gorgonian can be cryopreserved and subsequently cultured successfully.
Lory Z. Santiago-Vázquez and Nealie C. Newberger contributed equally to this publication. 相似文献
Southern elephant seals are important apex predators in a highly variable and unpredictable marine environment. In the presence
of resource limitation, foraging behaviours evolve to reduce intra-specific competition increasing a species’ overall probability
of successful foraging. We examined the diet of 141 (aged 1–3 years) juvenile southern elephant seals to test the hypotheses
that differences between ages, sexes and seasons in diet structure occur. We described prey species composition for common
squid and fish species and the mean size of cephalopod prey items for these age groups. Three cephalopod species dominated
the stomach samples, Alluroteuthis antarcticus, Histioteuthis eltaninae and Slosarczykovia circumantarcticus. We found age-related differences in both species composition and size of larger prey species that probably relate to ontogenetic
changes in diving ability and haul-out behaviour and prey availability. These changes in foraging behaviour and diet are hypothesised
to reduce intra-specific food competition concomitant with the increase in foraging niche of growing juveniles. 相似文献
Thirty-two brownfield sites from the city of Wolverhampton were selected from those with a former industrial use, wasteland
or areas adjacent to industrial processes. Samples (<2 mm powdered soil fraction) were analysed, using inductively coupled
plasma–atomic emission spectrometry (ICP–AES) for 20 elements. Loss on ignition and pH were also determined. A five-step chemical
sequential extraction technique was carried out. Single leach extraction with 0.12 M hydrochloric acid of Pb, Cu and Zn in
soil was determined as a first approximation of the bioavailability in the human stomach. Some of the sites were found to
have high concentrations of the potentially toxic elements Pb, Zn, Cu and Ni. The partitioning of metals showed a high variability,
however a number of trends were determined. The majority of Zn was partitioned into the least chemically stable phases (steps
1, 2 and 3). The majority of Cu was associated with the organic phase (step 4) and the majority of Ni was fractionated into
the residue phase (step 5). The majority of Pb was associated with the residue fraction (step 5) followed by Fe–Mn oxide fraction
(step 3). The variability reflects the heterogeneous and complex nature of metal speciation in urban soils with varied historic
histories. There was a strong inverse linear relationship between the metals Ni, Zn and Pb in the readily exchangeable phase
(step 1) and soil pH, significant at P < 0.01 level. There was a significant increase (P < 0.05) in the partitioning of Cu, Ni and Zn into step 4 (the organic phase) in soils with a higher organic carbon content
(estimated by loss on ignition). Copper was highly partitioned into step 4 as it has a strong association with organics in
soil but this phase was not important for the partitioning of Ni or Zn. The fractionation of Ni, Cu and Zn increased significantly
in step 3 when the total metal concentration increases (P < 0.01). The Fe–Mn oxide fraction becomes more important in soils elevated in these metals, possibly due to the scavenging
of metals by oxides. Cu and Pb extracted by HCl was statistically similar to the sum of the metals in steps 1 to 4 (P < 0.01) and HCl available Zn was statistically similar to the sum of Zn in steps 1 to 3 (P < 0.01). Step 4 (the organic phase) was not an important phase for Zn, so it was concluded that any Cu, Zn and Pb present
in soil in a nonresidue phase would be potentially available for uptake into the human system once soil has been ingested. 相似文献
To create a truly circular economy requires a shift from the traditional view of waste disposal to one of resource management. This is particularly important in developing countries, where municipal waste generation is increasing, and efficient recovery of economic value from waste is rarely achieved. Conducted in the University of Lagos (UoL), Nigeria, this study investigated the efficiency of a recycling scheme with the goal of making recommendations to improve the process. UoL’s recycling policy centers around source segregation of waste into color-coded bins. Waste audit was carried out using the output method and interviews were conducted with staff from the waste management team to understand practices on campus. Substantial contamination of colored bins with non-target material was observed. Organics (30%), mixed plastics (28%) and paper (24%) were the most abundant materials, hence have the greatest potential for recovery, and income generation, if segregation rates could be improved. Despite its recycling policy and infrastructure, 99% of UoL waste was going to landfill. Poor policy implementation results in low recovery rates. Targeted waste reduction and increased material recovery would enhance efficiency. Improved awareness of recycling benefits, in addition to policy enforcement, could serve as tools to increase stakeholder participation in recycling.
Interpersonal communication can influence the decisions people make about engaging in conservation behaviours. In-depth interviews with Tibetan pastoralists serve as the basis for examining interpersonal communication patterns and sources of interpersonal influence about grassland conservation behaviours. Herding and family groups are key collectives; salient sources of information vary across types of information. Salient individuals are those with credibility and means control: community leaders, elders, veterinarians, and government officials. Explicit information about conservation comes from religious leaders. The findings have significant implications for understanding the function and nature of interpersonal influence in unique population groups regarding conservation actions. 相似文献
Environmental change requires adaptive responses that are innovative, forward-looking and anticipatory, in order to meet goals for sustainability in socio-ecological systems. This implies transformative shifts in understanding as conceptualised by the idea of ‘double’- or ‘triple-loop learning’. Achieving this can be difficult as communities often rely on shorter-term coping mechanisms that purport to maintain the status quo. The use of participatory scenario planning to stimulate forward-looking social learning for adaptation was investigated through three contrasting community case studies on natural resource management in Latin America (in Mexico, Argentina and Colombia). Exploratory scenario narratives that synthesised local knowledge and future perceptions were used iteratively to define response options considered robust across multiple futures. Despite its intensive format, participants in each case agreed that scenario planning enabled a more systematic appraisal of the future. Scenarios facilitated innovation by providing scope to propose new types of responses and associated actions. Differences in local context meant that learning about future change developed in diverse ways, showing a need for a reflexive process. Reframing of key issues characteristic of double-loop learning did occur, albeit through different forms of interaction in each location. However, a shift towards transformative actions characteristic of triple-loop learning was less evident. Achieving this would appear to require ongoing use of scenarios to challenge social norms in light of changing drivers. Use of learning loops as a diagnostic to evaluate adaptive responses provided a useful reference framework although in practice both innovation and consolidative approaches can develop concurrently for responses to different issues. 相似文献
Abstract Residues of 2,4‐D (2,4‐dichlorophenoxyacetic acid) in air samples from several sampling sites in central and southern Saskatchewan during the spraying seasons in the 1966–68 and 1970–75 periods were determined by gas‐liquid Chromatographic techniques. Initially, individual esters of 2,4‐D were characterized by retention times and confirmed further by co‐injection and dual column procedures. Since 1973, however, only total 2,4‐D acid levels in air samples have been determined after esterification to the methyl ester and confirmed by gc/ms techniques whenever possible. Up to 50% of the daily samples collected during the spraying season at any of the locations and during any given year contained 2,4‐D, with butyl esters being found most frequently. The daily 24‐hr mean atmospheric concentrations of 2,4‐D ranged from 0.01 to 1.22 μg/m3, 0.01 to 13.50 μg/m3, and 0.05 to 0.59 μg/m for the iso‐propyl, mixed butyl and iso‐octyl esters, respectively. Even when the samples were analysed for the total 2,4‐D content, i.e. from 1973 onwards, the maximum level of the total acid reached only 23.14 μg/m. In any given year and at any of the sampling sites, about 30% of the samples contained less than 0.01 μg/m3 of 2,4‐D. In another 40% of the samples, the levels of 2,4‐D ranged from 0.01 to 0.099 yg/m. Only about 30% of the samples contained 2,4‐D concentrations higher than 0.1 μg/m3, with only 10% or less exceeding 1 μg/m3. None of the samples, obtained with the high volume particu‐late sampler, showed any detectable levels of 2,4‐D, indicating little or no transport of 2,4‐D adsorbed on dust particles or as crystals of amine salts. 相似文献
An eco-restoration system to remove excess nutrients and restore the agricultural ecosystem balance was proposed and applied from August 2006 to August 2008 in a residential-cropland complex area (1.4 × 105 m2) in Kunming, western China, where the self-purifying capacity of the agricultural ecosystem had been lost. The proposed eco-restoration system examined includes three main foci: farming management, bioremediation, and wastewater treatment. The results showed that the removal efficiencies of total phosphorus (TP) and total nitrogen (TN) from the complex wastewater were 83% and 88%, respectively. The Simpson’s diversity indices of macrophytes and zoobenthos indicated that the system had increased macrophyte and zoobenthic diversity as well as improved growth conditions of the plankton habitats. The results demonstrated that the proposed eco-restoration system is a promising approach for decreasing the output of nutrients from soil, improving agricultural ecosystem health, and minimizing the downstream eutrophication risk for surface waters. 相似文献