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The white-clawed crayfish Austropotamobius pallipes has experienced extensive population declines in its native range in the last century and is now a threatened species. European legislati...

Many aquatic species of conservation concern exist at low densities and are inherently difficult to detect or monitor using conventional methods. However, the introduction of environmental (e)DNA has recently transformed our ability to detect these species and enables effective deployment of limited conservation resources. Identifying areas for breeding, as well as the ecological distribution of species, is vital to the survival or recovery of a conservation species (i.e., areas of critical habitat). In many species, spawning events are associated with a higher relative abundance of DNA released within an aquatic system (i.e., gametes, skin cells etc.), making this the ideal time to monitor these species using eDNA techniques. This study aims to examine whether a “snapshot” eDNA sampling approach (i.e., samples taken at fixed points in chronological time) could reveal areas of critical habitat including spawning sites for our target species Petromyzon marinus. We utilized a species‐specific qPCR assay to monitor spatial and temporal patterns in eDNA concentration within two river catchments in Ireland over three consecutive years. We found that eDNA concentration increased at the onset of observed spawning activity and patterns of concentration increased from downstream to upstream over time, suggesting dispersal into the higher reaches as the spawning season progressed. We found P. marinus to be present upstream of several potential barriers to migration, sometimes in significant numbers. Our results also show that the addition of a lamprey‐specific fish pass at an “impassable” weir, although assisting in ascent, did not have any significant impact on eDNA concentration upstream after the pass had been installed. eDNA concentration was also found to be significantly correlated with both the number of fish and the number of nests encountered. The application of snapshot sampling techniques for species monitoring therefore has substantial potential for the management of low‐density species in fast‐moving aquatic systems. Irish Research Council Inland Fisheries Ireland

The Atlantic salmon (Salmo salar L.) has worldwide ecological, cultural and economic importance. The species has undergone extensive decline across its native range, yet concerns have been raised about its invasive potential in the Pacific. Knowledge on the distribution of this species is vital for addressing conservation goals.This study presents an eDNA assay to detect S. salar in water samples, using quantitative PCR (qPCR) technology. Species-specific primers and a minor groove binding (MGB) probe were designed for the assay, based on the mitochondrial cytochrome oxidase I (COI) gene.The results of this study indicate that eDNA is a highly sensitive tool for detecting S. salar in situ, and could potentially provide an alternative, non-invasive method for determining the distribution of this species.

The impact of fine sediments on both habitat quality and macroinvertebrate communities of riverine systems has been well documented over recent years. However, there is a paucity of studies examining the mechanisms that relate macroinvertebrate sensitivity and responses of individual macroinvertebrate species to burial by sediment. Laboratory-based burial experiments were undertaken to study the response of some EPT species including Baetis rhodani, Ecdyonurus insignis, Rhithrogena semicolorata, Hydropsyche siltalai, Rhyacophila dorsalis and the amphipod Gammarus duebeni to burial. A range of burial conditions were studied which included five sediment fractions at two burial depths. Responses were variable across species and, overall, the ranking of the determinants that impacted on species responses to burial was burial depth > sediment class > species source, with no detectable effect linked to body size. Increased burial depth had the most marked effects on emergence times, while slower escape times were also observed from the finer sediment classes. Species source also influenced responses with some upland species taking longer or failing to emerge from burial. Further mechanistic studies, based on EPT species, are required to enhance our understanding of how and at what level sediment affect species, an essential step in developing pressure-specific biological metrics.

Knowledge of the location, physical attributes and impacts of obstacles on river connectivity is a requirement for any mitigating action aimed at restoring the connectivity of a river system. Here, we present a study that recorded the numbers and physical diversity of obstacles in 10 river catchments in Ireland, together with the impact these structures had on overall river connectivity. A total of 372 obstacles were recorded, 3 of these were dams, and the remainder were low-head weirs/sluices, obstacles associated with road or rail crossings of rivers and natural structures. The degree of fragmentation was estimated in each catchment by calculating obstacle density and the Dendritic Connectivity Index (DCI). DCI scores were calculated for 4 native Irish fish species with different life-histories, namely diadromous (Atlantic salmon, sea trout, European eel, sea lamprey) and potamodromous (brown trout). Obstacle density ranged between 1.2 and 0.02 obstacles/km of river. Six of the 10 catchments had at least one obstacle located on the mainstem river at least 5 km from its mouth/confluence. These 6 catchments typically had the lowest connectivity scores for diadromous species and ranged between 0.6 and 44.1 (a fully connected river would receive a maximum score of 100). While there was no significant correlation between obstacle density and the DCI score for diadromous fish, a significant negative correlation was detected between obstacle density and the DCI score for potamodromous brown trout. Here, we highlight the merit of these obstacle assessments and associated challenges for decision-making relating to prioritisation of obstacles for removal or modification.

The white-clawed crayfishAustropotamobius pallipeshas undergone extensive declines within its native range in the last century. Because of its threatened status, European legislation requires the species to be regularly monitored and that Special Areas of Conservation (SACs) be designated for it. Knowledge on the distribution of this species is vital for addressing these needs. This study presents an environmental (e)DNA assay to detectA. pallipesin water samples, based on the mitochondrial cytochrome oxidase I (COI) gene, utilizing species-specific primers, a minor groove binding (MGB) probe and quantitative PCR. The results of this study indicate that eDNA is an effective tool for detectingA. pallipesin a lotic system, and could provide a valuable, non-invasive method for determining the distribution of this species.

This study finds that non-native species and warming temperatures have significant negative effects on Arctic char Salvelinus alpinus abundance in Irish lakes. Eutrophication was not important at the range of total phosphorus tested (0.005-0.023 mg l-1 ). Model results predict that S. alpinus occur across the temperature range sampled (8.2-19.7°C) when non-natives are absent, but S. alpinus catch is predicted to be close to zero irrespective of temperature when non-native catch is high. This result indicates that to persist, S. alpinus may require a habitat where non-natives are at low abundance or absent. Salvelinus alpinus segregated from other species along the thermal axis, inhabiting significantly colder water and actively avoided non-native species, which appeared to limit their distribution. The thermal niche realized by S. alpinus in non-native dominated lakes was thus compressed relative to native dominated lakes and S. alpinus population density was significantly lower. These findings were consistent even when the only non-native present was Perca fluviatilis. Temperature appeared to limit the distribution of non-native species, such that the presence of deep thermal refugia is currently facilitating S. alpinus co-existence with non-natives in associated lakes. Diet analysis identified P. fluviatilis as potential predators and competitors. This study provides strong evidence that non-native species are a key driver of low S. alpinus abundance in Irish lakes. Temperature increases associated with climate change are identified as a secondary concern, as they could erode S. alpinus' thermal niche and lead to their extirpation. The lower thermal buffering capacity of shallow lakes identifies these as higher risk systems. Salvelinus alpinus conservation in Ireland should focus on preventing future illegal non-native species introductions because unlike other stressors (e.g., eutrophication etc.), species introductions are rarely reversible.

The first comprehensive investigation of pike Esox lucius trophic ecology in a region (Ireland) where they have long been thought to be a non-native species is presented. Diet was investigated across habitat types (lake, river and canal) through the combined methods of stable-isotope and stomach content analyses. Variations in niche size, specialization and the timing of the ontogenetic dietary switch were examined, revealing pronounced opportunism and feeding plasticity in E. lucius, along with a high occurrence of invertivory (up to 60 cm fork length, LF ) and a concomitant delayed switch to piscivory. Furthermore, E. lucius were found to primarily prey upon the highly available non-native roach Rutilus rutilus, which may alleviate predation pressure on brown trout Salmo trutta, highlighting the complexity of dynamic systems and the essential role of research in informing effective management.

Elevated suspended sediment concentrations in fluvial environments have important implications for system ecology and even small concentrations may have serious consequences for sensitive ecosystems or organisms, such as freshwater pearl mussels (Margaritifera margaritifera). Informed decision making is therefore required for land managers to understand and control soil erosion and sediment delivery to the river network. However, given that monitoring of sediment fluxes requires financial and human resources which are often limited at a national scale, sediment mobilisation and delivery models are commonly used for sediment yield estimation and management. The Revised Universal Soil Loss Equation (RUSLE) is the most widely used model for overland flow erosion and can, when combined with a sediment delivery ratio (SDR), provide reasonable sediment load estimations for a catchment. This paper presents RUSLE factors established from extant GIS and rainfall datasets that are incorporated into a flexible catchment modelling approach. We believe that this is the first time that results from a RUSLE application at a national scale are tested against measured sediment yield values available from Ireland. An initial assessment of RUSLE applied to Irish conditions indicates an overestimation of modelled sediment yield values for most of the selected catchments. Improved methods for model and SDR factors estimation are needed to account for Irish conditions and catchment characteristics. Nonetheless, validation and testing of the model in this study using observed values is an important step towards more effective sediment yield modelling tools for nationwide applications.

This study focuses on stream sections within a relatively low nutrient catchment in south-east Ireland in an attempt to characterize the probable effects of riparian canopy on salmonid diet and prey selectivity within two size classes of nursery stream. Sampling found that brown trout Salmo trutta diet changed significantly in response to riparian canopy regardless of stream size. The observation that S. trutta within unshaded stream sites did not feed on drifting terrestrial prey items to the same extent as those within shaded streams was not due to a lack of availability of this food source. There was no evidence to suggest that S. trutta selectively choose particular prey items.

Stable isotope and gut content analyses, in conjunction with backcalculated length-at-age estimates of growth, were employed to examine the relationship between trophic ecology and growth rate of a successful invader, Rutilus rutilus, in eight lakes in Ireland. The data revealed that R. rutilus was a trophic generalist in Irish lakes. It utilized a greater proportion of pelagic resources in mesotrophic lakes than in eutrophic lakes, potentially due to a greater density of benthic macroinvertebrates in eutrophic systems. The species was characterized by a large dietary and isotopic niche width and high temporal and spatial variations in diet. Growth rates were typical of those found in the native range of the species and were unrelated to either lake productivity or fish's diet. A generalist trophic ecology confers significant advantages on an invasive species, allowing it to exploit a variety of novel resources and fluctuations in prey availability.

Objectives: Hip impingement and associated labral tears are a common source of pain in adolescent and young adult athletes. The majority of current literature focuses on adult populations while there is a relative paucity of literature on younger athletes. It has been our experience that the proper diagnosis and management of patients with labral pathology in the adolescent athletes is often delayed. One of the reasons for this delay may be the sensitivity of MRIs in diagnosing hip pathology. The sensitivity of MRI to detect labral tears in adults has been reported to be 71-91%. However, the sensitivity of MRI to detect labral pathology in adolescent athletes is unknown. The purpose of this study was to evaluate the sensitivity of MRI in diagnosing labral tears in an adolescent and young adult population. Methods: Patients undergoing hip arthroscopy by 3 sports medicine trained orthopedic surgeons between 2006-2018 were retrospectively reviewed. Patients were included in this study if they had a MRI and subsequently confirmed labral pathology during hip arthroscopy. Patients were excluded if they had a history of prior surgeries of the ipsilateral hip, did not have a diagnosis of femoral-acetabular impingement (FAI) or acetabular labral pathologies, were over the age of 25 or if the MRI did not have a radiologist report available for review. The MRI reports of the patients who met study criteria were reviewed to determine if the radiologist suspected labral pathology. The MRIs were also reviewed by a sports medicine fellowship trained orthopaedic surgeon who was not involved in the patients’ care and was blinded to the radiologist reports. The radiology report and the orthopaedist’s read were then compared against the surgical findings to determine the sensitivity and false negative rates for MR imaging in this patient population. Results: A total of 140 hips in 132 patients (26 males, 106 females) were included in this study with a mean age of 16.7 ± 2.4 years. Of this study cohort, 112 patients had a labral repair and 20 had a labral debridement. Results showed that of the 140 hip MRIs, the official radiology report described the presence of labral pathology in only 76 MRI scans; indicating that the MRI has a sensitivity of 55% and a false negative rate of 44% for the presence of labral pathology. Results of the blinded orthopaedic surgeon’s review showed that of the 140 hip MRIs available, the presence of labral pathology was seen in only 92 MRI scans with a sensitivity of 65% and a false negative rate of 34%. Conclusion: Routine MRI scans had a low sensitivity and high false negative rate for labral pathology in adolescent and young adults regardless of reviewer, even in the presence of retrospective bias. The sensitivity of MRI for labral pathology in this population is lower than that reported in the literature for adult patients. These findings have implications for clinicians who rely heavily on MRI results and radiologist reports in their clinical decision making which may result in delays in appropriate surgical management.

Aim: We investigated genetic variation of Irish pike populations and their relationship with European outgroups, in order to elucidate the origin of this species to the island, which is largely assumed to have occurred as a human-mediated introduction over the past few hundred years. We aimed thereby to provide new insights into population structure to improve fisheries and biodiversity management in Irish freshwaters. \ud Location: Ireland, Britain and continental Europe. \ud Methods: A total of 752 pike (Esox lucius) were sampled from 15 locations around Ireland, and 9 continental European sites, and genotyped at six polymorphic microsatellite loci. Patterns and mechanisms of population genetic structure were assessed through a diverse array of methods, including Bayesian clustering, hierarchical analysis of molecular variance, and approximate Bayesian computation. \ud Results: Varying levels of genetic diversity and a high degree of population genetic differentiation were detected. Clear substructure within Ireland was identified, with two main groups being evident. One of the Irish populations showed high similarity with British populations. The other, more widespread, Irish strain did not group with any European population examined. Approximate Bayesian computation suggested that this widespread Irish strain is older, and may have colonized Ireland independently of humans. \ud Main conclusions: Population genetic substructure in Irish pike is high and comparable to the levels observed elsewhere in Europe. A comparison of evolutionary scenarios upholds the possibility that pike may have colonized Ireland in two ‘waves’, the first of which, being independent of human colonization, would represent the first evidence for natural colonization of a non-anadromous 42 freshwater fish to the island of Ireland. Although further investigations using comprehensive genomic techniques will be necessary to confirm this, the present results warrant a reappraisal of current management strategies for this species.

Understanding the feeding habits of aquatic invertebrates under reference conditions can contribute to our understanding of community assemblages in fresh waters. Here, seasonal changes in the diet of three species of Ephemeroptera from Irish high status rivers were investigated. A fluorescent dye, 4'6 diamidino-2-phenylindole, was used to differentiate the various types of gut contents and to allow bacteria and biofilm matrix to be visualised. Through interpretation of gut contents and feeding strategy plots, Baetis rhodani was found to have a generalist diet with detritus, algae and biofilm the main food types. Two congeneric species, Ecdyonurus venosus and E. insignis, were found to be detritus specialists. Seasonal sampling indicated that biofilm can provide a valuable food source to E. venosus at times of high flow when detritus is not readily available. There was evidence of niche separation in summer when E. insignis and E. venosus co-existed. E. insignis fed on coccoid algae while E. venosus consumed no coccoid algae. B. rhodani consistently ingested a similar broad diet throughout the year. A detritus-based diet is likely nutrient poor leading to lower growth rates. These findings are discussed in the context of the behaviour of these species and sensitivity to nutrient enrichment.

The purpose of this study was to consider the relative importance of several habitat variables in explaining the patterns in the structure of macroinvertebrate assemblages in open-water habitats, in relatively intact bogs and fens, which should inform conservation strategies. It was hypothesised that variables relating to the size of the water body would differentiate the communities and that some species would be unique to certain conditions. The macroinvertebrate communities from pools >100 m2, 10.1–100 m2 and Sphagnum hollows were characterised using sweep sampling for eight intact peatland sites across four bog types, and related to habitat variables including pool size, Sphagnum cover and hydrochemistry. Results showed community composition and structure differed significantly between deep, permanent pools and shallow, drought-sensitive Sphagnum hollows, with larger invertebrates, such as Odonates and Dytiscinae, rarely found in the hollows. Sphagnum cover accounted for a substantial amount of the variation in community composition. An examination of life-history strategies found species dependent on predictable conditions for juvenile development to be more abundant in pools. In contrast, taxa that could delay juvenile development until conditions were favourable were more abundant in Sphagnum hollows. These results highlight the importance of habitat heterogeneity in maintaining macroinvertebrate diversity in peatlands.

Laboratory and field assessments were used to determine whether the construction of culverts affects brown trout (Salmo trutta L.) egg survival through the introduction of elevated sediment levels....

M. Millane (corresponding author; email: michael. millane® fisheriesireland.ie), M.F. O'Grady and K. Delanty, Inland Fisheries Ireland, Swords Business Campus, Swords, Co. Dublin; M. Kelly Quinn, Freshwater Biodiversity, Ecology and Fisheries Research Group, School of Biology and Environmental Science, University College Dublin.

SUMMARY 1. Recent proliferation of hybridisation in response to anthropogenic ecosystem change, coupled with increasing evidence of the importance of ancient hybridisation events in the formation of many species, has moved hybridisation to the forefront of evolutionary theory. 2. In spite of this, the mechanisms (e.g. differences in trophic ecology) by which hybrids co-exist with parental taxa are poorly understood. A unique hybrid zone exists in Irish freshwater systems, whereby hybrid offspring off two non-native cyprinid fishes often outnumber both parental species. 3. Using stable isotope and gut content analyses, we determined the trophic interactions between sympatric populations of roach (Rutilus rutilus), bream (Abramis brama) and their hybrid in lacustrine habitats. 4. The diet of all three groups displayed little variation across the study systems, and dietary overlap was observed between both parental species and hybrids. Hybrids displayed diet, niche breadth and trophic position that were intermediate between the two parental species while also exhibiting greater flexibility in diet across systems.

One main challenge in conservation biology is to preserve genetic variability and adaptive variation within and among populations. However, constant anthropogenic habitat modifications have severe effects on the evolutionary dynamics shaping wild populations and pose a serious threat to the natural evolution of biodiversity. The aim of the present study was to unravel the genetic structuring of brown trout (Salmo trutta) populations in the largest freshwater catchment in Ireland, whose habitats have experienced major human-mediated changes over at least two centuries. A total of 419 juvenile fish were sampled from nine main rivers in the Corrib catchment and were genotyped using 12 microsatellites. Both Bayesian clustering and F ST-based analyses of genetic variance sorted these populations into five main genetically distinct groups, characterized by different extent of genetic differentiation among populations. These groups were also characterized by some degree of admixture, which can be partly explained by recent gene flow. Overall, the study suggests that the Corrib trout may conform to a metapopulation model with local populations that show different degrees of isolation and are interconnected by various level of gene flow. Results add further insights into metapopulation evolutionary dynamics and provide a useful basis to implement appropriate conservation strategies.

Aquatic ecosystems are experiencing increasing disturbance from multiple stressors caused by anthropogenic activities. The potential for multiple stressors to modify each others’ impacts is not well understood. Legislation such as the EU Water Framework Directive (WFD) requires the development of tools to assess human impacts in aquatic systems that incorporate ecological elements, such as macroinvertebrates. Nutrient enrichment and invasive species are major threats to freshwater systems. The invasive zebra mussel Dreissena polymorpha is a conspicuous invader in freshwater aquatic systems in Europe and North America, and has been linked to drastic changes in macroinvertebrate communities and lake ecology. In 31 lake sites varying in nutrient pressure and in the presence or absence of D. polymorpha we tested three ecological quality assessment tools based on macroinvertebrate assemblages (% Sensitive Taxa to Total Phosphorus (TP), TP Score and Indicator Taxa Metric) and two basic ecological metrics. There were highly significant changes in macroinvertebrate diversity, structure, and composition associated with the invasion by D. polymorpha. While the three metrics performed consistently well in non-invaded systems, they lost explanatory power for eutrophication pressure in invaded systems. Our results suggest that metrics may need to be developed separately for invaded and non-invaded systems, and that the interaction between alien species and nutrient enrichment requires further investigation.

Niche variation between hybrid taxa and their parental species has been deemed imperative to the persistence of hybrid populations in nature. However, the ecological factors promoting hybrid establishment remain poorly understood. Through the application of a multidisciplinary approach integrating genetics, morphometry, life-history, and trophic ecology, we studied the hybrids of roach (Rutilus rutilus L.) and bream (Abramis brama L.), and their parental species inhabiting an Irish lake. The roach × bream hybrid exhibited a body shape intermediate of that of the parental species. Diet analyses depicted the hybrid as a generalist, feeding on all prey items consumed by either parental species. Stable isotope data confirm the trophic niche breadth of hybrids. A significant correlation between body shape and diet was detected, suggesting that the intermediate phenotype of hybrids might play a role in their feeding abilities, resulting in the utilization of a broader trophic spectrum than the parental species. Growth and age class structure analyses also yielded a scenario that is consistent with the ecological success of hybrids. Genetic analyses suggest that the majority of hybrids result from first-generation crosses between the parental species; however, a potentially significant proportion of back-crosses with bream were also detected. The recent introduction of roach and bream into Irish waters, as well as the climatic and ecological features of the colonized habitats, can explain the remarkable success of the roach × bream hybrid in Ireland. The adaptive significance of hybridization and its demographic consequences for the parental species are discussed. © 2010 The Linnean Society of London, Biological Journal of the Linnean Society, 2010, 99, 768–783.

Perla bipunctata is the most common species of Perlidae in Ireland occurring in fast flowing, clean rivers and small streams. Although a common component of freshwater biological studies, little is known about the autecology of this stonefly. Monthly kick and Surber samples were taken over a 1-year period in the upper reaches of the River Liffey (4th order) to determine the life history of larvae. Perla bipunctata has a merovoltine life cycle taking no less than three years to complete the immature stages. Life history plots suggest two periods of egg hatching, followed by two separate cohorts developing over different lengths of time. Mature larvae from both cohorts synchronise and emerge as adults over a short period in early summer. The merovoltine life cycles of long lived invertebrates like P. bipunctata emphasise the importance of such species in reflecting the ecological quality of freshwaters over a long period of time.

The zebra mussel, Dreissena polymorpha (Pallas 1771), invaded Lough Sheelin in the midlands of Ireland in 2001. In order to assess the status of the mussel population in the lake, the distribution, extent of colonisation, abundance, biomass and size-frequency structure of post-settlement stages were studied in 2005 and 2006. In addition, changes to water quality parameters in the lake postestablishment were assessed with reference to the pre-invasion period. Zebra mussels were found throughout the lake at most sites on all main categories of substrates examined (stony and soft substrate; submerged vegetation: Characeae, Elodea spp., Cladophora spp., Potamogeton spp. and Myriophyllum spp., and emergent vegetation: Phragmites australis and Schoenoplectus lacustris). Overall, increases in density and biomass of mussels were recorded from 2005 to 2006. Analysis of physiochemical data show a reduction in chlorophyll a with an increase in water transparency, however the total phosphorus concentration remains high. This paper highlights the common misconception that zebra mussel introductions lead to overall improvements in water quality.

Freshwater acidification continues to be a major problem affecting large areas of Europe, and while there is evidence for chemical recovery, similar evidence for biological recovery of freshwaters is sparse. The need for a methodology to identify waterbodies impacted acidification and to assess the extent of biological recovery is relevant to the EU Water Framework Directive, which requires methods to quantify differences in biology between impacted and unimpacted or reference sites. This study presents a new WFD-compliant metric based on diatoms (Diatom Acidification Metric: DAM) for assessing the acidification status of rivers. A database of 558 benthic diatom samples and associated water chemistry data was assembled. Diatom taxa were assigned to one of 5 indicator classes on the basis of their pH optimum, assessed using Gaussian logistic regression, and these indicator values used to calculate a DAM score for each site using weighted averaging. Reference sites were selected on the basis of their acid neutralising capacity (ANC) and calcium concentration, and a regression model developed to predict expected DAM for each site using pH and total organic carbon (TOC) concentration. Site-specific DAM scores were used to calculate ecological quality ratios ranging from ≥ 1, where the diatom assemblage showed no impact, to (theoretically) 0, when the diatom assemblage was indicative of major anthropogenic activities. The boundary between ‘high’ and ‘good’ status was defined as the 25th percentile of Ecological Quality Ratios (EQRs) of all reference sites. The boundary between ‘good’ and ‘moderate’ status was set at the point at which nutrient-sensitive and nutrient-tolerant taxa were present in equal relative abundance. The methodology was evaluated using long-term data from 11 sites from the UK Uplands Waters Monitoring Network and is shown to perform well in discriminating naturally acid from acidified sites.

The paucity of species inventories for the freshwater Oligochaeta in Ireland probably reflects the high level of taxonomic skill required to fully identify individual specimens. In many studies of the freshwater fauna the Oligochaeta are identified to order or family level only. During the present study, initiated by the Limnology Unit, Department of Zoology, University College Dublin, in excess of 1,100 records from 331 aquatic sites were compiled for a range of lotic and lentic habitats in the Republic of Ireland. In addition, a survey of the published literature was completed in order to augment records obtained in the field. Species-level identifications were undertaken on all suitable matenral, and a comprehensive checklist was generated. The field study yielded thirty five species in the families Naididae, Tubificidae and Lumbriculidae. This number rose to forty three species after a survey of published records. Lumbriculus variegatus (Muller) and Stylodrilus heringianus Clapar&de were the most frequently encountered species, being found at 191 and 155 sites respectively. Ten new Irish records were discovered during the course of this project.

The binding of the adenosine A(2A) receptor antagonist [3H] 4-(2-[7-amino-2-(2-furyl)[1,2,4]-triazolo[2,3-a][1,3,5]triazin-5-ylamino]ethyl)phenol ([3H]ZM 241385) to mouse brain and spinal cord was investigated. In brain homogenates, single-site binding was observed with a Bmax of 299+/-28 fmol mg(-1) protein and a Kd of 0.75+/-0.08 nM. In autoradiographic studies, there was a high density of specific binding of [3H]ZM 241385 in the striatum, with a very low density in the cortex and no binding elsewhere in the brain or in the spinal cord. All specific binding of [3H]ZM 241385 was lost in genetically modified mice lacking the adenosine A(2A) receptor, confirming the selectivity of this radioligand.

Morphogenesis between yeast and hyphal growth is a characteristic associated with virulence in Candida albicans and involves changes in the cell wall. In Saccharomyces cerevisiae, the transcription factor pair Ace2p and Swi5p are key regulators of cell wall metabolism. Here, we have characterized the CaACE2 gene, which encodes the only C. albicans homologue of S. cerevisiae ACE2 and SWI5. Deleting CaACE2 results in a defect in cell separation, increased invasion of solid agar medium and inappropriate pseudohyphal growth, even in the absence of external inducers. The mutant cells have reduced adherence to plastic surfaces and generate biofilms with distinctly different morphology from wild-type cells. They are also avirulent in a mouse model. Deleting CaACE2 has no effect on expression of the chitinase gene CHT2, but expression of CHT3 and the putative cell wall genes CaDSE1 and CaSCW11 is reduced in both yeast and hyphal forms. The CaAce2 protein is localized to the daughter nucleus of large budded cells at the end of mitosis. C. albicans Ace2p therefore plays a major role in morphogenesis and adherence and resembles S. cerevisiae Ace2p in function.

A growing body of evidence suggests that excessive Zn 2 + release plays a key role in inducing neuronal death during central nervous system injury. However, the possible cytotoxicity of extracellular Zn 2 + to oligodendrocyte lineage cells remains unknown. Employing cultures of rat oligodendrocyte progenitor cells (OPC), we report here that OPC are vulnerable to increased extracellular Zn 2 + levels and that pyruvate limits Zn 2 + -induced OPC death. Zn 2 + -induced concentration-dependent (pEC 5 0 = -4.1 ′ 0.1) OPC death, which was insensitive to both α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (Evans Blue) and L-type Ca 2 + channel (nicardipine) inhibition. Neither kainate nor nicardipine influenced OPC 6 5 Zn 2 + accumulation, in contrast with the Zn 2 + ionophore, pyrithione. Cytotoxic extracellular Zn 2 + concentrations failed to increase OPC reactive oxygen species production and the antioxidant reagents, trolox, N,N'-diphenyl-1,4-phenylenediamine and N-tert-butyl-α-phenylnitrone did not afford significant protection from Zn 2 + insults. The apoptotic Inducer staurosporine induced the appearance of known apoptotic markers [pyknotic nuclei and caspase-3 specific (120 kDa) α-fodrin cleavage fragment], events not reproduced with Zn 2 + insults. Zn 2 + insults were also insensitive to the pancaspase inhibitor Z-VAD-fmk. However, pyruvate afforded significant OPC protection from lethal Zn 2 + insults. We conclude that cultured OPC are vulnerable to Zn 2 + insults, via a nonoxidative stress and noncaspase-3-based mechanism, involving Zn 2 + inhibition of OPC glycolysis.

Female flatfish grow faster than males. Our goal is to use immersion in estradiol as a method for producing all female populations of summer flounder ( Paralichthys dentatus ). To this end, we measured uptake and clearance of estradiol in the whole-body of larval and juvenile summer flounder. Uptake reached an initial plateau within 30 min and was accumulated above the exposure concentration (EC) in juveniles, but not larvae. An EC of 16 nM significantly elevated whole-body estradiol concentrations in both larvae and juveniles. We recommend an EC of 50–100 nM to raise estradiol levels to high physiological levels. Depuration was significant within 4 h after transfer to clean water and complete after 24 h. Estradiol in the exposure water was lowered to undetectable levels within 1 h of charcoal filtration. This information should be useful to investigators working on sex differentiation in this and other species, or in the areas of vitellogenin biology and endocrine disruption.

Monitoring of the protected white-clawed crayfish Austropotamobius pallipes (Lereboullet) has been carried out in the headwaters of the Nore River since 1995. In recent years a reduction in crayfish abundance had become apparent. Some populations had completely disappeared. Adult crayfish were sampled using the baited trap method while juveniles were sampled using a modified surber sampler. The temporal variation in baited trap data was found to be significant at three of the sites while significant variation in enclosure sampling data was found at two sites. In an effort to ascertain why the populations had disappeared a possible relationship between water quality and adult and juvenile crayfish numbers was investigated. Water quality was assessed using both chemical and macroinvertebrate data. Macroinvertebrate sampling revealed deterioration in water quality at all sites. Results also showed the disappearance of crayfish from both Q3 and Q3-4 waters at some sites yet crayfish remain at these Q-ratings at other sites. Therefore the Q-rating below which crayfish cannot survive cannot clearly be defined. However, no clear correlation was observed between the water chemistry data and the crayfish data. Crayfish populations at the Fertagh (FRT) site appear to be surviving intermittent pollution and eutrophic conditions where pre-dawn oxygen sags reach lows of 4.4 mg/l O2 . Deterioration in water quality as indicated by the Q-value biotic index coincided with reduced crayfish catches. There is no evidence to suggest that predation be it of aquatic or terrestrial origin is a major contributing factor.

The effects of co-supplementing healthy volunteers with iron (14 mg/day ferrous sulphate) and vitamin C (either 60 mg/day or 260 mg/day as ascorbic acid) on levels of oxidative DNA damage in white blood cells were studied. The subjects were divided into two groups: one group of 20 volunteers with a higher mean initial level of plasma vitamin C (71.9 +/- 14.0 mumol/l) and a second group of 18 volunteers with a lower mean level (50.4 +/- 25.8 mumol/l). In the first group there was a significant rise in several oxidative DNA base damage products and in total oxidative DNA damage in DNA extracted from white blood cells, but not in 8-hydroxyguanine, after 6 weeks of supplementation. However, after 12 weeks levels returned approximately to normal. In the group with the lower initial level of plasma ascorbate, presupplemental levels of oxidative DNA damage were higher and decreased on supplementation with iron and ascorbate. Since oxidative DNA damage has been suggested as a risk factor for the development of cancer, the implications of increased levels in well-nourished subjects after iron/ascorbate supplementation are disturbing in view of the frequent use of dietary supplements containing both iron salts and ascorbate.

Macroinvertebrates were sampled from forty-seven sites on upland soft water streams in eastern Ireland. Classification generated four recognisable faunal communities or site groups which differed in biological, physical and chemical character; these patterns were supported by ordination analyses. The environmental gradients which probably influenced water quality were broadly categorised into geology, distance from source or elevation and forestry. Faunal diversity and abundance were reduced in both high altitude and extensively afforested sites compared to moorland sites. Whereas, Plecoptera dominated the fauna at most sites, many taxonomic groups such as the Ephemeroptera and members of the family Elmidae were absent from high altitude and forested areas. The impact of afforestation was most evident at those sites which were located in forest plantations or were on catchments with extensive (>25%) closed canopy (>12 yr) afforestation. Low levels (

The present study evaluates evidence for linkage of schizophrenia to chromosome 6p24-p22. An independent sample of 211 families ascertained on the basis of having an affected sib-pair diagnosed with schizophrenia or schizoaffective disorder was assessed with seventeen polymorphic markers spanning a 37cM region. Linkage analysis was performed with parametric and non-parametric methods to test for cosegregation using 4 models of inheritance. Neither two-point nor multipoint non-parametric analyses reached significance at a level less than 0.01 for any markers examined in the region and lod score analyses were not suggestive of linkage. Based on initial findings in the present data set and recently published linkage results, two specific areas were densely covered with markers and tested for linkage disequilibrium. After correcting for multiple comparisons within each locus, no significant deviation from expected allele transmission ratios was observed. The present findings together with the published literature fail to find consistent evidence of a linkage for schizophrenia to a single locus on chromosome 6.

In response to reported schizophrenia linkage findings on chromosomes 3, 6 and 8, fourteen research groups genotyped 14 microsatellite markers in an unbiased, collaborative (New) sample of 403-567 informative pedigrees per marker, and in the Original sample which produced each finding (the Johns Hopkins University sample of 46-52 informative pedigrees for chromosomes 3 and 8, and the Medical College of Virginia sample of 156-191 informative pedigrees for chromosome 6). Primary planned analyses (New sample) were two-point heterogeneity lod score (lod2) tests (dominant and recessive affected-only models), and multipoint affected sibling pair (ASP) analysis, with a narrow diagnostic model (DSM-IIIR schizophrenia and schizoaffective disorders). Regions with positive results were also analyzed in the Original and Combined samples. There was no evidence for linkage on chromosome 3. For chromosome 6, ASP maximum lod scores (MLS) were 2.19 (New sample, nominal p = 0.001) and 2.68 (Combined sample, p = .0004). For chromosome 8, maximum lod2 scores (tests of linkage with heterogeneity) were 2.22 (New sample, p = .0014) and 3.06 (Combined sample, p = .00018). Results are interpreted as inconclusive but suggestive of linkage in the latter two regions. We discuss possible reasons for failing to achieve a conclusive result in this large sample. Design issues and limitations of this type of collaborative study are discussed, and it is concluded that multicenter follow-up linkage studies of complex disorders can help to direct research efforts toward promising regions.

24 páginas, 2 figuras, 1 tabla., The protection, preservation and restoration of aquatic ecosystems and their functions are of global importance. For European states it became legally binding mainly through the EUWater Framework Directive (WFD). In order to assess the ecological status of a given water body, aquatic biodiversity data are obtained and compared to a reference water body. The quantified mismatch obtained determines the extent of potential management actions. The current approach to biodiversity assessment is based on morpho-taxonomy. This approach has many drawbacks such as being time consuming, limited in temporal and spatial resolution, and error-prone due to the varying individual taxonomic expertise of the analysts. Novel genomic tools can overcome many of the aforementioned problems and could complement or even replace traditional bioassessment. Yet, a plethora of approaches are independently developed in different institutions, thereby hampering any concerted routine application. The goal of this Action is to nucleate a group of researchers across disciplines with the task to identify gold-standard genomic tools and novel ecogenomic indices for routine application in biodiversity assessments of European fresh- and marine water bodies. Furthermore, DNAqua-Net will provide a platform for training of the next generation of European researchers preparing them for the new technologies. Jointly with water managers, politicians, and other stakeholders, the group will develop a conceptual framework for the standard application of eco-genomic tools as part of legally binding assessments.

Ecologically, potential bioindicator taxa operate at different scales within agricultural ecosystems, and thereby provide a means to investigate the influence of changing management practice on biological diversity at different scales within the agro-ecosystem. Surveys of grassland plant species at field level, parasitoid Hymenoptera at the field and farm scale, and bird populations and habitats at farm scale were carried out on 119 grass-based farms across three regions in the Republic of Ireland. In addition, habitat richness and aquatic macroinvertebrates were quantified at landscape scale. Agricultural intensity on the surveyed farms was quantified by mean farm stocking rate, calculated as livestock units per ha (LU/ha), and generalised linear mixed models used to evaluate relationships between stocking rate and the incidence of chosen bioindicator groups. Field scale bioindicators (plant species richness and parasitoid taxon richness and abundance) were negatively associated with mean farm stocking rate. Over much of its observed range, mean farm stocking rate was positively associated with total bird species richness and abundance, and the species richness and abundance of farmland bird indicator species recorded in the winter season. However, these relationships were quadratic, and above a relatively high upper limit of 2.5–3.5 LU/ha, further increase in farm stocking rate had a negative influence. Results demonstrate that different bioindicators measured at different spatial scales vary in their response to agricultural intensity. The lack of a consistent bioindicator response to farm stocking rate suggests that within predominantly farmed regions, maximising biodiversity requires a careful targeting and monitoring with bioindicator taxa that are informative of influences at relevant operational scales. The insights provided may then be much more informative for the design and implementation of agri-environment measures that maximise biodiversity within farmed landscapes. DG 19/11/2012

Niemann-Pick Disease, type C (NPC) is a fatal, neurodegenerative, lysosomal storage disorder. It is a rare disease with broad phenotypic spectrum and variable age of onset. These issues make it difficult to develop a universally accepted clinical outcome measure to assess urgently needed therapies. To this end, clinical investigators have defined emerging, disease severity scales. The average time from initial symptom to diagnosis is approximately 4 years. Further, some patients may not travel to specialized clinical centers even after diagnosis. We were therefore interested in investigating whether appropriately trained, community-based assessment of patient records could assist in defining disease progression using clinical severity scores. In this study we evolved a secure, step wise process to show that pre-existing medical records may be correctly assessed by non-clinical practitioners trained to quantify disease progression. Sixty-four undergraduate students at the University of Notre Dame were expertly trained in clinical disease assessment and recognition of major and minor symptoms of NPC. Seven clinical records, randomly selected from a total of thirty seven used to establish a leading clinical severity scale, were correctly assessed to show expected characteristics of linear disease progression. Student assessment of two new records donated by NPC families to our study also revealed linear progression of disease, but both showed accelerated disease progression, relative to the current severity scale, especially at the later stages. Together, these data suggest that college students may be trained in assessment of patient records, and thus provide insight into the natural history of a disease.

Male and female rats were segregated from birth (sexually isolated animals). Additional litters containing both male and female pups were kept as controls (mixed-housed animals). beta-FNA (5 mg/kg) or water was administered SC at day 0 or day 7 to isolated and mixed-housed animals. The development of mu-opioid receptors and nociceptive responses in the two groups was assessed at day 7 or 14, respectively. Mu-receptor binding was measured in whole brain using (3H) DAGO as a binding ligand and nociception assessed using the tail immersion test. beta-FNA treatment depressed mu-receptors when measured 1 but no 7 days later. However, male and female rats treated at day 0 with beta-FNA had lower brain protein content. Sexual isolation had little effect on mu-receptor number and did not augment the beta-FNA effect. However, isolation increased pain sensitivity in 7-day-old animals and in 14-day-old females. beta-FNA treatment had little effect on nociceptive threshold but reversed the effects of sexual isolation.

The diet of brown trout, Salmo trutta L., in the Owendoher Stream, a tributary of the River Dodder, was examined at monthly intervals from June 1981 to May 1982. The diets of the three main age groups, 0+, 1 + and 2+/3+ fish, have been separately described and compared. Ephemeropteran nymphs, larval and adult chironomids as well as a variety of other adult insects were the most frequently consumed foods. While 0+ trout largely concentrated on aquatic organisms, adult insects, in particular those of terrestrial origin, became progressively more important in the diet with increasing age of the fish. Daily ration calculations indicated that food intake was highest during the summer and early autumn months when it was well in excess of maintenance requirements. This corresponded to a period of good growth. For the remainder of the year food intake was not much higher than maintenance requirements. In fact, 1+ and older (2+/3+) fish probably experienced an energy deficit on occasions during the winter which was reflected in their poor condition and weight loss. The relationship between growth and production in the system are further discussed.

The ontogenesis of kappa-opioid receptors has been studied in the postnatal period from day 5 to day 30 using the highly selective kappa-site ligand [3H]U-69593 in binding studies. Analyses of saturation curves revealed a marked increase in the binding capacities between day 5 and day 10 with no further increment in the number of sites up to adult ages confirming a distinct ontogenetic profile from mu- and delta-sites. When expressed per mg protein the number of sites declined from day 10 to adult. At all postnatal ages there was little change in receptor affinity. This ontogenetic profile is broadly in agreement with studies using non-selective kappa-ligands but the number of sites labelled by [3H]U-69593 is markedly lower in both the neonate and the adult.

A molecular cloning strategy has been designed to isolate the gene that encodes the small cytoplasmic RNA (scRNA) component of bacterial signal recognition particles. Using this strategy a putative Listeria monocytogenes scRNA lambda gt11 recombinant clone was isolated. A previously described complementation assay developed to genetically select functional homologues of 4.5S RNA and scRNA of bacteria confirmed that the lambda gt11 recombinant clone isolated encoded for the scRNA from L. monocytogenes. A secondary structure for this scRNA is proposed and a phylogenetic comparison of the 276 base L. monocytogenes scRNA with previously characterised Gram-positive bacterial scRNAs is also presented.

We completed a systematic genome-wide search for evidence of loci linked to schizophrenia using a collection of 70 pedigrees containing multiple affected individuals according to three phenotype classifications: schizophrenia only (48 pedigrees; 70 sib-pairs); schizophrenia plus schizoaffective disorder (70 pedigrees; 101 sib-pairs); and a broad category consisting of schizophrenia, schizoaffective disorder, paranoid or schizotypal personality disorder, psychosis not otherwise specified (NOS), delusional disorder, and brief reactive psychosis (70 pedigrees; 111 sib-pairs). All 70 families contained at least one individual affected with chronic schizophrenia according to DSM-III-R criteria. Three hundred and thirty-eight markers spanning the genome were typed in all pedigrees for an average resolution of 10.5 cM (range, 0–31 cM) and an average heterozygosity of 74.3% per marker. The data were analyzed using multipoint nonparametric allele-sharing and traditional two-point lod score analyses using dominant and recessive, affecteds-only models. Twelve chromosomes (1, 2, 4, 5, 8, 10, 11, 12, 13, 14, 16, and 22) had at least one region with a nominal P value 2.0, allowing for heterogeneity. These regions will be saturated with additional markers and investigated in a new, larger set of families to test for replication. Am. J. Med. Genet. (Neuropsychiatr. Genet.) 81:364–376, 1998. © 1998 Wiley-Liss, Inc.

The effects of acute severe illness on pituitary-gonadal function were determined in 35 men and 19 women, including 12 who were postmenopausal. Seventeen men and 5 women had traumatic brain injury which resulted in coma. Twelve postmenopausal and 2 premenopausal women had intracranial vascular accidents. Eleven men had myocardial infarctions, while 7 men underwent elective surgery. Serial plasma samples were examined for testosterone (men), percentage of ultrafiltrable testosterone (men), estradiol (women), sex hormone-binding globulin, LH, and FSH. In men, mean testosterone levels fell by 271 +/- 72 (+/- SE), 202 +/- 63 and 195 +/- 75 ng/dl within 24 h of brain injury, myocardial infarction, or elective surgery, representing decreases of 55%, 43%, and 58%. Further declines occurred in the first and third groups to mean nadirs of 93 +/- 16 and 117 +/- 5 ng/dl, respectively. During recovery of neurological function there was no correlation between the testosterone level and the degree of neurological impairment; testosterone levels eventually returned to normal (627 +/- 77 ng/ml). The percentage of ultrafiltrable testosterone and sex hormone-binding globulin did not change in any group. Although significant decreases in mean immunoreactive LH and FSH levels were found after head trauma, and decreases in FSH were found in the men after surgery, these changes occurred after the decline in testosterone. Despite the fall in basal gonadotropin levels in the head trauma group, there were no significant differences in the gonadotropin responses to GnRH (100 micrograms) in 4 patients during their acute illness or recovery. LH, FSH, and estradiol levels in the premenopausal women were significantly lower on the second day of brain injury (LH, 10.3 +/- 4.7 vs. 3.5 +/- 0.6 mIU/ml; FSH, 3.8 +/- 1.9 vs. 1.4 +/- 0.8 mIU/ml, estradiol, 200 +/- 41 vs. 102 +/- 16 pg/ml) and remained suppressed for 7 days. Gonadotropin levels also fell in the postmenopausal women within 24 h; reductions in LH of 74% and in FSH of 62% were present by day 7 of study. We conclude that both men and women who are critically ill uniformly develop temporary hypogonadotropic gonadal insufficiency regardless of their illness. In men, it is manifested by low testosterone levels, while a comparable decrease in estradiol is present in women. The low testosterone concentrations are not due to reduced sex hormone-binding capacity. Based upon our data in postmenopausal women, hypogonadotropism also occurs in the presence of nonfunctioning gonads. Although our studies do not completely establish the pathophysiology of this disorder, they suggest a suprapituitary origin.

During the period June 1982-84 hatchery-reared brown trout, Salmo trutta L., fry were Stocked into stretches of the Owendoher. a trout nursery stream on the east coast of Ireland. These experiments were designed to examine the survival of stocked fry and to estimate the carrying capacity of the system. During the first year fry were stocked into sectors already supptorting wild fish at densities normal for the system. In the following year fry numbers were artificially reduced prior to stocking with the hatchery-reared fish. Mortality of the stocked fry was high after release with less than 33% of the fish surviving beyond the first 3 weeks. No stocked fish survived after October 1982. In the second year, however, 2-9% of the fish survived. The best survival rates were achieved where wild fry numbers were lowest. Regardless of the initial stocking density the various experiments yielded autumn fry densities (0.07-0.7 fish/m2) similar to those at unstocked sites (0.1-0.62 fish/m2). Stocking did not increase recruitment to the 1+ group and again 1+ densities (0.15-0.35 fish/m2) similar to unstocked sites (0.07-0.39 fish/m2) were obtained at the end of each year. These results suggest that spawning and recruitment in the Owendoher yield population densities approaching the maximum carrying capacity of the stream. The system appears to support a maximum summer fry density in the region of 1 fish/m2 and a maximum autumn density of 0.7 fish/m2.

Quantitative enzymological studies on extracts of cerebral grey matter and liver from calves with GM i gangliosidosis showed a 70-80%, reduction in β-galactosidase activity for p-nitrophenyl-β-D-galacto-pyranoside at pH 4.5. Levels of acid phosphatase activity were either normal or slightly elevated compared with control calves.