11 research outputs found

    The palaeolimnology of Lough Murree, a brackish lake in the Burren, Ireland.

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    Peer-reviewed. This document is the Accepted Manuscript version of a Published Work that appeared in final form in Biology & Environment: Proceedings of the Royal Irish Academy. To access the final edited and published work see doi: 10.3318/BIOE.2013.23Lough Murree, a rock/karst barrier lagoon, is superficially isolated from the sea and seasonal variations in lake water level reflect precipitation and groundwater variation. Lake salinity is influenced by subsurface saline intrusions, occasional barrier overwash together with precipitation and groundwater inflow, leading to poikilohaline conditions. Palaeolimnological reconstructions in Murree support the supposition that the lagoon was once superficially connected to the sea around the mid-nineteenth century. Physical, chemical and biological proxies suggest an evolution to more freshwater conditions. Uncertainties about the timing of the transition persist because of an unresolved sediment chronology. The isolation of Murree from the Atlantic Ocean has promoted the formation of dense charophyte beds composed of lagoonal specialist species, which are able to tolerate large variations in salinity

    A multi-proxy palaeolimnological study to reconstruct the evolution of a coastal brackish lake (Lough Furnace, Ireland) during the late Holocene

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    Peer-reviewed. This document is the Accepted Manuscript version of a Published Work that appeared in final form in Palaeogeography, Palaeoclimatology, Palaeoecology, Vol 383-384, August 2013, Pages 1-15. To access the final edited and published work see doi: http://dx.doi.org/10.1016/j.palaeo.2013.04.016This study examines the evolution of Lough Furnace, a coastal brackish lake in the west of Ireland, using high-resolution sensors in the water column and palaeolimnological examination of the sediment archive. Palaeoenvironmental reconstructions suggest that meromixis formed as a result of sea level rise prior to ca. 4000 cal. yr BP. Increased seawater inflow has progressively led to permanent water stratification, which caused the onset of anoxia, making the monimolimnion a harsh environment for biological life. Diatom floristic interpretations suggest a progressive upcore increase in salinity, which is paralleled by a reduction in cladocera remains. Diagenetic processes have not altered the sediment organic matter signature. Organic matter mainly derives from freshwater DOC and appears to be linked to the presence of peat bogs in the catchment as confirmed by the C/N ratio. Upcore variations in the C/N ratio with a ca. 800-year periodicity have been interpreted as the result of alternating dry and wet climatic phases during the late Holocene, which appear synchronous with the NAO and long-term solar cycles. The current hydrology is largely controlled by freshwater inflow, which determines permanent meromictic conditions. Overturns are rare, requiring a specific combination of factors such as exceptionally dry and warm summers followed by cool autumns. According to the climate projections for the next century in Ireland, permanent meromictic conditions will probably continue

    Contrasting pelagic plankton in temperate Irish lakes: the relative contribution of heterotrophic, mixotrophic, and autotrophic components, and the effects of extreme rainfall events

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    The mobilisation of energy from allocthonous carbon by heterotrophic bacterioplankton can be proportionally more important than autotrophic production in humic lakes. Moreover, increasing levels of dissolved organic carbon (DOC) in many aquatic systems linked to increases in precipitation, which in turn may be related to changing climate, mean that this heterotrophic component of the food web may play an increasing role in the overall transfer and production of energy, particularly within peatland catchments. While such catchments are common in the temperate northwest Atlantic regions of Europe, studies describing the seasonal dynamics of the heterotrophic, mixotrophic, and autotrophic components of their aquatic food webs are rare. In this study, the biomass of these pelagic components was enumerated over 1 year in 2 oligotrophic lakes, both situated in peatland catchments in the west of Ireland but with contrasting DOC concentrations. Bacterial biomass dominated the pelagic food web of the more humic lake, Lough Feeagh, while autotrophic phytoplankton biomass was greatest in the clearwater lake, Lough Guitane. The biomass of potentially mixotrophic flagellates was also slightly larger in the Lough Guitane, while phagotrophic ciliate biomass was comparable between the 2 lakes. An extreme precipitation event led to a significant increase in bacterial biomass while simultaneously depressing autotrophic production for several months in the humic lake. Extreme precipitation in the clearwater lake also depressed autotrophic production but did not give rise to significant increases in bacterial biomass. This quantification of autotrophic, mixotrophic, and heterotrophic components provides a vital first step in understanding how pelagic communities contribute to net ecosystem productivity, and thus how Irish peatland lakes may be affected by projected climate changes

    Neutrinoless double-beta decay search with CUORE and CUORE-0 experiments

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    The Cryogenic Underground Observatory for Rare Events (CUORE) is an upcoming experiment designed to search for the neutrinoless double-beta decays. Observation of the process would unambiguously establish that neutrinos are Majorana particles and provide information on their absolute mass scale hierarchy. CUORE is now under construction and will consist of an array of 988 TeO2 crystal bolometers operated at 10 mK, but the first tower (CUORE-0) is already taking data. The experimental techniques used will be presented as well as the preliminary CUORE-0 results. The current status of the full-mass experiment and its expected sensitivity will then be discussed

    Impaired flickering of the permeability transition pore causes SPG7 spastic paraplegia

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    Mutations of the mitochondrial protein paraplegin cause hereditary spastic paraplegia type 7 (SPG7), a so-far untreatable degenerative disease of the upper motoneuron with still undefined pathomechanism. The intermittent mitochondrial permeability transition pore (mPTP) opening, called flickering, is an essential process that operates to maintain mitochondrial homeostasis by reducing intra-matrix Ca2+ and reactive oxygen species (ROS) concentration, and is critical for efficient synaptic function

    Extended Glasgow Outcome Scale to Evaluate the Functional Impairment of Patients With Subcortical Band Heterotopia: A Multicentric Cross-sectional Study

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    Background: Subcortical band heterotopia (SBH) is a rare malformation of the cortical development characterized by a heterotopic band of gray matter between cortex and ventricles. The clinical presentation typically includes intellectual disability and epilepsy. Purpose: To evaluate if the Extended Glasgow Outcome Scale-pediatric version (EGOS-ped) is a feasible tool for evaluating the functional disability of patients with (SBH). Method: Cross-sectional multicenter study of a cohort of 49 patients with SBH (female n = 30, 61%), recruited from 23 Italian centers. Results: Thirty-nine of 49 (80%) cases showed high functional disability at EGOS-ped assessment. In the poor result subgroup (EGOS-ped >3) motor deficit, language impairment, and lower intelligence quotient were more frequent (P < 0.001, P = 0.02, and P = 0.01, respectively); the age at epilepsy onset was remarkably lower (P < 0.001); and the prevalence of epileptic encephalopathy (West syndrome or Lennox-Gastaut-like encephalopathy) was higher (P = 0.04). The thickness and the extension of the heterotopic band were associated with EGOS-ped score (P < 0.01 and P = 0.02). Pachygyria was found exclusively among patients with poor outcome (P < 0.01). Conclusions: The EGOS-ped proved to be a reliable tool for stratifying the functional disability of patients with SBH. According to this score, patients could be dichotomized: group 1 (80%) is characterized by a poor overall functionality with early epilepsy onset, thick heterotopic band, and pachygyria, whereas group 2 (20%) is characterized by a good overall functionality with later epilepsy onset and thinner heterotopic band

    The Palaeolimnology of Lough Murree, A Brackish Lake in the Burren, Ireland

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    A multi-proxy palaeolimnological study to reconstruct the evolution of a coastal brackish lake (Lough Furnace, Ireland) during the late Holocene

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