FRCH - I+D+i - GIDTAP::Artículos en revistashttp://hdl.handle.net/20.500.12272/61512024-03-29T06:55:29Z2024-03-29T06:55:29ZEmbryonic shell shape as an early indicator of pollution in marine gastropodshttp://hdl.handle.net/20.500.12272/99602024-03-20T15:28:43Z2021-02-19T00:00:00ZEmbryonic shell shape as an early indicator of pollution in marine gastropods
Gastropods shell shape has been proposed as a good indicator of environmental changes while geometric morphometric (GM) is a powerful tool to detect such changes. Shell shape pattern in adults of the marine gastropod Buccinanops deformis was proved to be correlated with imposex incidence and maritime traffic in populations of Patagonia. We explore through GM the shell shape variation of B. deformis intracapsular embryos in pre-hatching stages of development, in two populations with contrasting maritime traffic and imposex incidence. Embryonic shell shape from polluted and unpolluted areas was significantly different in apex, lateral, aperture and siphonal channel. The same shell shape pattern was observed previously in B. deformis adult specimens. Our results demonstrate that the embryonic shell shape is an early biomarker that could be used as a tool to detect the response to environmental pollution studying abundant egg capsules laid in the field but protecting reproductive adults.
2021-02-19T00:00:00ZPhotosensitizing role of R-phycoerythrin red protein and ß-carboline alkaloids in Dye sensitized solar cell. Electrochemical and spectroscopic characterizationhttp://hdl.handle.net/20.500.12272/94782024-02-14T16:19:01Z2019-11-13T00:00:00ZPhotosensitizing role of R-phycoerythrin red protein and ß-carboline alkaloids in Dye sensitized solar cell. Electrochemical and spectroscopic characterization
Dye-sensitized solar cell (DSSC) technology represents a valuable source for renewable energy production. Although with a rather low conversion efficiency, the continuous improvement of the price/performance ratio is making this technology more competitive than other sources of electrical power generation. To date, one of the major challenges is the search of novel and low-cost photosensitizers, a key player in the overall photo-conversion process. Natural dyes have shown to be an excellent alternative that still needs to be further explored. In this work, the spectroscopic and electrochemical properties of two different families of naturally occurring pigments (i.e, ß-carboline alkaloids (ßCs) and the red protein R-phycoerythrin (R-PE)) as well as their role in DSSCs are addressed. DSSC assemblies show that R-PE represents a highly suitable photosensitizer showing quite a high stability with a relative high solar energy to electricity conversion efficiency (n=0.11%) when comparing with other recombinant proteins (n=0.30%). Algae extracts used without further purification showed herein the highest efficiencies. The latter fact has a concomitant positive effect on the overall production cost of these photovoltaic cells. Surprisingly, and despite their positive effect on the coating of the semiconductor surface, the use of ßCs as additive decreases the overall conversion efficiency of the R-PE based DSSCs evaluated. Data support the hypothesis these alkaloids would be blocking the incident UVB/UVA radiation.
2019-11-13T00:00:00ZPress, pulse, and perceptions : how does media attention signal perceptions about environmental crises?http://hdl.handle.net/20.500.12272/87542023-11-08T19:26:18Z2023-01-23T00:00:00ZPress, pulse, and perceptions : how does media attention signal perceptions about environmental crises?
At what point do environmental phenomena become crises, and how do these impact the quantity and quality of media attention? As climate patterns change, societies face crises that are slow-moving in nature (such as sea level rise and drought) or fast-changing (such as hurricanes or flash floods). A third type of event is those that are slow-occurring while at the same time being punctuated by extreme, fast-changing occurrences. The practical and theoretical consequences of these complex events are often difficult to pinpoint. We argue that it is necessary to evaluate how the features of such events affect stakeholder perceptions. We do so by analyzing water-quality crises in Northeastern Patagonia, Argentina. Combining turbidity data collected over a decade with 10 years of newspaper articles published in response to high turbidity events, we assess the extent and sentiment of media attention to better understand the linkage between extreme natural events and how these relate to the media agenda. We find that as events increase in duration and intensity, their media coverage increases. These effects are more accentuated when the duration and intensity of an event surpass limits imposed by local infrastructure and practices.
2023-01-23T00:00:00ZSurfing the tide: homeward migration of sea trout (Salmo trutta) in a Patagonian riverhttp://hdl.handle.net/20.500.12272/82702023-08-16T16:30:38Z2022-06-23T00:00:00ZSurfing the tide: homeward migration of sea trout (Salmo trutta) in a Patagonian river
This study evaluates the influence of marine and freshwater conditions on the timing of river entry and upstream migration of sea trout (Salmo trutta) in the Grande River of Tierra del Fuego, Patagonia. We analysed the in-river catch-and-release records from a group of fishing lodges that dominate the Grande River fishery during January–April 2008 (n = 5029 fish) as a function of environmental variables: tidal amplitude, stage in the lunar cycle, river discharge, and river water temperature along the homeward migration season. We discuss the value of the daily catch rate as an abundance index in the Grande river, then analyse the temporal structure of the tidal cycle in the Grande River estuary, a macro-tidal environment with a mean tidal amplitude of 5.7 m, and analyse the fit of a generalized additive model to trout catches on a daily basis in four sections along the river to identify the environmental variables that may affect trout abundance throughout the homeward migration. Fish catches in each section of the river were differentially affected by specific environmental variables: tidal amplitude had a positive and significant effect on catches in the lower river sections, whereas water temperature and river discharge significantly affected catches in upper sections (positive effect of temperature; negative effect of discharge). Catches in the lower section clearly reflect the river entry stage of the homeward migration, with a bi-modal shape significantly correlated with the tidal cycle. The first peak was composed mainly of larger multi-sea-winter trout that move upstream, whereas the second one had a wider range of fish lengths, including a large proportion of small and maybe nonreproductive trout that overwinter in the lower river. Based on our results, we conclude that the large tides in the Grande River estuary strongly affect the river entry timing of sea trout. The underlying mechanisms of this effect may be a combination of increased olfactory recognition and increased tidal transport modulated by the seasonal tidal cycle, which operates on trout during coastal migration to produce the pulses observed in the Grande River sea trout run. In the middle and upper sections of the river, where the tidal effect at river entry was dissipated as upstream migration progressed, trout catches increased with water temperature and decreased with river discharge, which may operate through their influence on in-river migration rate and abundance, but also through changes in catchability.
2022-06-23T00:00:00Z