Otolith chemistry, stomach contents and stable isotope analysis of a snapper (Pagrus auratus) caught in the Waikato River at Ngaruawahia

Analyses of stomach contents, stable isotopes and otolith microchemistry were carried out in order to ascertain the length of freshwater residence of a snapper (Pagrus auratus) caught in the Waikato River at Ngaruawahia in a net set for grey mullet(Mugil cephalus). Results of all analyses suggest that the snapper had spent all of its life in a marine environment with no evidence of freshwater residence in the otolith. Stable isotope analyses (δ15N = 17.0‰, δ13C = –17.1‰) indicated an entirely marine diet, and the stomach contents (two New Zealand screwshells, Maoricolpus roseus, and a hermit crab, Pagurus novizelandiae), suggested that the fish had not fed while in freshwater. However, this does not preclude the possibility that the snapper quickly travelled up the river, without eating, and was caught very soon after

Assessing movement of rainbow trout and common smelt between Lake Rotoiti and Lake Rotorua using otolith chemical signatures: A summary of work so far

This study used otolith microchemistry to investigate movement of common smelt and rainbow trout between Lake Rotorua and Lake Rotoiti. Rainbow trout were collected from Lake Rotoiti, Lake Rotorua and the Ohau Channel, and smelt were collected from several locations in Lake Rotoiti and Lake Rotorua

An investigation of koi carp (Cyprinus carpio) movement in the Waikato region using laser ablation otolith microchemistry

The koi carp Cyprinus carpio is an invasive fish that has reached high numbers and biomass in the North Island of New Zealand, particularly in the Waikato region. This species has a variety of negative effects on aquatic ecosystems, increasing turbidity, uprooting aquatic macrophytes, and affecting water column nutrient levels. Recent research in Australia and New Zealand has shown that adult carp, though largely restricted to small scale movements, are capable of moving long distances. Movement in adult carp may be underestimated by these studies, and comparatively little is known about the movement of smaller carp. This study examined the feasibility of using laser ablation otolith microchemistry to track koi carp movement and identify spawning areas. Water samples from six locations (Lake Waahi, Lake Whangape, Lake Waikare, the Whangamarino River, and the Waikato River at Aka Aka and Rangiriri) were analysed using inductively coupled plasma mass spectrometry (ICP-MS). Significant differences between sites were found in the water concentrations of many elements. Koi carp were collected from the above locations, as well as from Opuatia Stream, Pungarehu Stream, the Maramarua River and Lake Hakanoa. The elemental concentrations in the asteriscus otoliths were analysed using laser ablation inductively coupled plasma mass spectrometry (LA‐ICP-MS). Elemental concentrations in the edges and nuclei of adult koi carp and the edges of young-of-the-year (YOY) koi carp were significantly different between capture sites. No significant differences were found in elemental concentrations between sites in the nuclei of YOY koi carp. A discriminant function analysis (DFA) was carried out using the otolith edge elemental signatures of koi carp. The model used Ba, Sr, Mg, Rb and Zn concentrations to differentiate between four capture locations: the Waikato River, Pungarehu Stream, Lake Waahi, and Lake Waikare and Pungarehu Stream. The DFA was able to correctly predict the capture location of 82% of koi carp using their otolith edge elemental signatures. The classification functions created using koi carp otolith edge signatures were then used as a training set to classify otolith nucleus signatures. The otolith nuclei of 80% of YOY koi carp were classified to their site of capture, suggesting they had not moved between locations. The majority of adult koi carp caught at Lake Waikare, Whangamarino River, Pungarehu Stream and Opuatia Stream had nucleus signatures matching their capture sites, indicating that these fish originated from their capture location. Koi carp from other sites likely moved there from another location. The majority of adult koi carp (88%) caught at the Waikato River at Rangiriri had otolith nucleus signatures matching Lake Waikare and Pungarehu Stream. Adult koi carp caught at Lake Waahi and the Waikato River at Aka Aka had otolith signatures corresponding to a range of locations. While some areas (Lake Waikare, Pungarehu Stream) appear to have resident koi carp populations that likely originated there, others (Lake Waahi, the Waikato River) appear to have koi carp populations of mixed origin. These results indicate that Lake Waikare, Pungarehu Stream and the Whangamarino River may be important sources of koi carp recruits in the lower Waikato region

Factors controlling common smelt abundance and rainbow trout growth in the Rotorua Lakes, New Zealand

Recreational fisheries are of considerable ecological, economic and cultural importance worldwide, and understanding the factors that influence them is an important goal of fishery managers. The two most important factors influencing the growth of fish are habitat quality and food supply. This study was undertaken to gain a better understanding of how these two factors influence rainbow trout growth in the Rotorua Lakes, central North Island, New Zealand, by surveying prey dynamics, quantifying rainbow trout diet, and assessing the effects of environmental factors and population density on trout growth. Rainbow trout populations in lakes of New Zealand’s central North Island mainly prey upon common smelt (Retropinna retropinna), a small, widespread, pelagic species. Routine monitoring of smelt populations would assist in trout fishery management decisions, especially for optimisation of stocking rates and timing. To recommend an effective capture technique for smelt, we tested purse seining, beach seining, drop netting, and boat electrofishing in Lake Rotoiti. Boat electrofishing in the littoral zone at night allowed us to collect more adult smelt than all other methods, and long boat electrofishing transects across the lake were the most effective method for capturing a wide size range of smelt specimens, including larvae. Most methods also caught other species as bycatch. In terms of the number of smelt caught, the most effective method was (1) boat electrofishing at night, followed by (2) scoop nets at night (i.e. boat electrofishing with the current turned off), then (3) beach seining during the day. The first two sampling methods are suggested as the best methods for collecting data on seasonal dynamics, growth, and reproduction of smelt. For enumeration of the total smelt population, these methods should be carried out in the littoral and pelagic zones and combined with a method such as hydroacoustics that can enumerate smelt in the deeper waters of the pelagic zone. Population dynamics of common smelt in lakes are not well understood. To determine the factors influencing smelt populations in Lake Rotoiti, we examined seasonal changes in habitat and resource use by measuring spatial and seasonal changes in smelt abundance, body condition, and diet. We also characterised seasonal and spatial changes in smelt reproductive state and benthic egg abundance. Smelt abundance in the littoral zone and surface waters of the pelagic zone was highest in autumn, coinciding with peaks in smelt body condition, gonadosomatic index, and benthic egg abundance. Smelt larvae were only found in the pelagic zone, and were more abundant in spring than in summer and autumn. Body condition of smelt varied throughout the year, and was lowest in winter, a period of low abundance of littoral invertebrates and zooplankton. Smelt caught in the littoral zone during the day consumed a range of benthic and pelagic invertebrates and smelt eggs, while at night, smelt caught in the littoral and pelagic zones consumed zooplankton, smelt eggs and larval common bully (Gobiomorphus cotidianus). The amount of food in the stomach relative to smelt mass was higher in the littoral zone than in the pelagic zone, suggesting that food resources in the littoral zone exceed those in the pelagic zone. Predation on zooplankton was highest in winter and spring, and smelt eggs formed a large proportion of smelt diet in autumn and winter. Stomach contents and stable isotope analyses showed that smelt undergo an ontogenetic change in diet, from mainly zooplankton as juveniles to mainly benthic invertebrates as adults. The information obtained in this study is necessary for managing smelt and their predator—rainbow trout—in lakes. To better understand the prey requirements of trout in central North Island lakes, we characterised seasonal and ontogenetic changes in diet and prey energy density of rainbow trout in Lake Rotoiti. Common smelt was the dominant prey item of rainbow trout larger than 200 mm (77.8% of diet by mass), followed by koura (freshwater crayfish Paranephrops planifrons; 6.3%), common bully (5.5%), and koaro (Galaxias brevipinnis; 3.4%). Juvenile rainbow trout (<200 mm) consumed amphipods, aquatic and terrestrial insects, oligochaetes, tanaid shrimps, and smelt. Trout consumed koaro only in autumn and winter; consumption of other species did not vary seasonally. The maximum size of smelt consumed increased with increasing trout size, but trout continued to consume small smelt even as large adults. Consumption of larger prey items (koaro and koura) also increased with increasing trout size. This study indicates the importance of smelt for sustaining rainbow trout populations, as predation on other species was relatively low. These findings provide a basis for bioenergetics modelling of rainbow trout populations in lakes of the central North Island of New Zealand. Though the factors influencing the growth of salmonids in cool-temperate and boreal climates are well understood, we lack an understanding of the influences on salmonid growth in warm-temperate areas, especially in lakes. To determine the combined effects of environmental factors, including habitat, on rainbow trout growth, we investigated the growth patterns of rainbow trout (Oncorhynchus mykiss) in nine warm-temperate New Zealand lakes of contrasting morphometry, mixing regime, and trophic state. Mark-recapture data (some collected by anglers) from hatchery trout releases during eight consecutive years were used to calculate growth parameters and body condition factor. Fish growth rates and condition factors were highest in deep (≥20 m mean depth) lakes of moderate trophic state. Overall, growth rate increased with increasing lake size and volume of favourable habitat (i.e. dissolved oxygen >6.0 mg L-1 and temperature <21°C), but decreased with increasing turbidity, chlorophyll a, and nitrogen concentrations. A classification and regression tree (CART) analysis found that variables describing habitat volume were the most important determinants of trout growth rate, and correlates of trophic state (chl a, conductivity) were important secondary determinants of trout growth rate. These results suggest that lake morphometry and trophic state are important attributes structuring overall habitat quality and thus influencing growth of rainbow trout in lakes in warm-temperate climates. The effects of future ecosystem degradation and climate warming on trout growth are likely to be most severe in shallow, eutrophic lakes. To investigate the carrying capacity and factors affecting growth of rainbow trout in Lake Rotoiti, we employed a bioenergetics model to assess the influence of past stocking rates, timing of releases, and prey abundance on growth and prey consumption. We hypothesised that stocking rates and prey abundance would affect growth and prey consumption by influencing per-capita prey availability, and that the environmental conditions encountered by fish at the time of stocking would affect growth and consumption. Prey consumption of stocked rainbow trout was calculated with the Wisconsin bioenergetics model. We calculated growth trajectories based on data from trout that were stocked into the lake in spring and autumn from 1995 to 2009 and then re-captured by anglers. Diet, prey energy density, body mass lost due to spawning, and lake temperature were measured locally. There was no difference in tag return rate between fish released in spring and autumn. Though trout released in autumn were smaller initially, they grew at a faster rate than trout released in spring. The ratio of observed to predicted change in biomass at the maximum consumption rate by individual trout in the first year of lake residence was negatively correlated with the number of yearlings released in a cohort, suggesting that stocking rates (347–809 fish ha-1 year-1) caused density-dependent effects on growth. Common smelt accounted for 85% of total prey consumption. However, no significant relationship was found between prey consumption by individual trout and adult smelt abundance, suggesting that more detailed investigations of smelt abundance are required to predict trout growth rates. Because there is little risk of non-human predation of stocked fish in Lake Rotoiti, and winter temperatures are mild (11–14°C), stocking smaller trout (~160 mm fork length) in autumn is likely to produce larger fish than stocking larger fish (~200 mm fork length) in spring. Possible reasons for this difference include higher prey abundance in the littoral zone in autumn and more suitable temperature and dissolved oxygen habitat in autumn-winter. These results suggest that optimal stocking strategies in warm-temperate systems may differ to those in cooler temperate regions

Diet of rainbow trout in Lake Rotoiti: an energetic perspective

We characterised seasonal and ontogenetic changes in diet and prey energy density of rainbow trout (Oncorhynchus mykiss) in Lake Rotoiti, New Zealand, to better understand the prey requirements of trout in central North Island lakes. Common smelt (Retropinna retropinna) was the dominant prey item of rainbow trout larger than 200 mm (77.8% of diet by weight), followed by kōura (freshwater crayfish Paranephrops planifrons; 6.3%), common bully (Gobiomorphus cotidianus; 5.5%), and kōaro (Galaxias brevipinnis; 3.4%). Juvenile rainbow trout (<200 mm) consumed amphipods, aquatic and terrestrial insects, oligochaetes, tanaid shrimps, and smelt. Trout consumed kōaro only in autumn and winter; consumption of other species did not vary seasonally. The maximum size of smelt consumed increased with increasing trout size, but trout continued to consume small smelt even as large adults. Consumption of larger prey items (kōaro and kōura) also increased with increasing trout size. This study indicates the importance of smelt for sustaining rainbow trout populations, as predation on other species was relatively low. These findings provide a basis for bioenergetic modelling of rainbow trout populations in lakes of the central North Island of New Zealand

Effects of antiplatelet therapy on stroke risk by brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases: subgroup analyses of the RESTART randomised, open-label trial

Background Findings from the RESTART trial suggest that starting antiplatelet therapy might reduce the risk of recurrent symptomatic intracerebral haemorrhage compared with avoiding antiplatelet therapy. Brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases (such as cerebral microbleeds) are associated with greater risks of recurrent intracerebral haemorrhage. We did subgroup analyses of the RESTART trial to explore whether these brain imaging features modify the effects of antiplatelet therapy

Genomic analyses in Cornelia de Lange Syndrome and related diagnoses: Novel candidate genes, <scp>genotype–phenotype</scp> correlations and common mechanisms

Cornelia de Lange Syndrome (CdLS) is a rare, dominantly inherited multisystem developmental disorder characterized by highly variable manifestations of growth and developmental delays, upper limb involvement, hypertrichosis, cardiac, gastrointestinal, craniofacial, and other systemic features. Pathogenic variants in genes encoding cohesin complex structural subunits and regulatory proteins (NIPBL, SMC1A, SMC3, HDAC8, and RAD21) are the major pathogenic contributors to CdLS. Heterozygous or hemizygous variants in the genes encoding these five proteins have been found to be contributory to CdLS, with variants in NIPBL accounting for the majority (&gt;60%) of cases, and the only gene identified to date that results in the severe or classic form of CdLS when mutated. Pathogenic variants in cohesin genes other than NIPBL tend to result in a less severe phenotype. Causative variants in additional genes, such as ANKRD11, EP300, AFF4, TAF1, and BRD4, can cause a CdLS‐like phenotype. The common role that these genes, and others, play as critical regulators of developmental transcriptional control has led to the conditions they cause being referred to as disorders of transcriptional regulation (or “DTRs”). Here, we report the results of a comprehensive molecular analysis in a cohort of 716 probands with typical and atypical CdLS in order to delineate the genetic contribution of causative variants in cohesin complex genes as well as novel candidate genes, genotype–phenotype correlations, and the utility of genome sequencing in understanding the mutational landscape in this population

ENIGMA-anxiety working group : Rationale for and organization of large-scale neuroimaging studies of anxiety disorders

Altres ajuts: Anxiety Disorders Research Network European College of Neuropsychopharmacology; Claude Leon Postdoctoral Fellowship; Deutsche Forschungsgemeinschaft (DFG, German Research Foundation, 44541416-TRR58); EU7th Frame Work Marie Curie Actions International Staff Exchange Scheme grant 'European and South African Research Network in Anxiety Disorders' (EUSARNAD); Geestkracht programme of the Netherlands Organization for Health Research and Development (ZonMw, 10-000-1002); Intramural Research Training Award (IRTA) program within the National Institute of Mental Health under the Intramural Research Program (NIMH-IRP, MH002781); National Institute of Mental Health under the Intramural Research Program (NIMH-IRP, ZIA-MH-002782); SA Medical Research Council; U.S. National Institutes of Health grants (P01 AG026572, P01 AG055367, P41 EB015922, R01 AG060610, R56 AG058854, RF1 AG051710, U54 EB020403).Anxiety disorders are highly prevalent and disabling but seem particularly tractable to investigation with translational neuroscience methodologies. Neuroimaging has informed our understanding of the neurobiology of anxiety disorders, but research has been limited by small sample sizes and low statistical power, as well as heterogenous imaging methodology. The ENIGMA-Anxiety Working Group has brought together researchers from around the world, in a harmonized and coordinated effort to address these challenges and generate more robust and reproducible findings. This paper elaborates on the concepts and methods informing the work of the working group to date, and describes the initial approach of the four subgroups studying generalized anxiety disorder, panic disorder, social anxiety disorder, and specific phobia. At present, the ENIGMA-Anxiety database contains information about more than 100 unique samples, from 16 countries and 59 institutes. Future directions include examining additional imaging modalities, integrating imaging and genetic data, and collaborating with other ENIGMA working groups. The ENIGMA consortium creates synergy at the intersection of global mental health and clinical neuroscience, and the ENIGMA-Anxiety Working Group extends the promise of this approach to neuroimaging research on anxiety disorders

Genome-wide meta-analysis of 241,258 adults accounting for smoking behaviour identifies novel loci for obesity traits

Few genome-wide association studies (GWAS) account for environmental exposures, like smoking, potentially impacting the overall trait variance when investigating the genetic contribution to obesity-related traits. Here, we use GWAS data from 51,080 current smokers and 190,178 nonsmokers (87% European descent) to identify loci influencing BMI and central adiposity, measured as waist circumference and waist-to-hip ratio both adjusted for BMI. We identify 23 novel genetic loci, and 9 loci with convincing evidence of gene-smoking interaction (GxSMK) on obesity-related traits. We show consistent direction of effect for all identified loci and significance for 18 novel and for 5 interaction loci in an independent study sample. These loci highlight novel biological functions, including response to oxidative stress, addictive behaviour, and regulatory functions emphasizing the importance of accounting for environment in genetic analyses. Our results suggest that tobacco smoking may alter the genetic susceptibility to overall adiposity and body fat distribution.Peer reviewe

Effects of antiplatelet therapy after stroke due to intracerebral haemorrhage (RESTART): a randomised, open-label trial

Background: Antiplatelet therapy reduces the risk of major vascular events for people with occlusive vascular disease, although it might increase the risk of intracranial haemorrhage. Patients surviving the commonest subtype of intracranial haemorrhage, intracerebral haemorrhage, are at risk of both haemorrhagic and occlusive vascular events, but whether antiplatelet therapy can be used safely is unclear. We aimed to estimate the relative and absolute effects of antiplatelet therapy on recurrent intracerebral haemorrhage and whether this risk might exceed any reduction of occlusive vascular events. Methods: The REstart or STop Antithrombotics Randomised Trial (RESTART) was a prospective, randomised, open-label, blinded endpoint, parallel-group trial at 122 hospitals in the UK. We recruited adults (≥18 years) who were taking antithrombotic (antiplatelet or anticoagulant) therapy for the prevention of occlusive vascular disease when they developed intracerebral haemorrhage, discontinued antithrombotic therapy, and survived for 24 h. Computerised randomisation incorporating minimisation allocated participants (1:1) to start or avoid antiplatelet therapy. We followed participants for the primary outcome (recurrent symptomatic intracerebral haemorrhage) for up to 5 years. We analysed data from all randomised participants using Cox proportional hazards regression, adjusted for minimisation covariates. This trial is registered with ISRCTN (number ISRCTN71907627). Findings: Between May 22, 2013, and May 31, 2018, 537 participants were recruited a median of 76 days (IQR 29–146) after intracerebral haemorrhage onset: 268 were assigned to start and 269 (one withdrew) to avoid antiplatelet therapy. Participants were followed for a median of 2·0 years (IQR [1·0– 3·0]; completeness 99·3%). 12 (4%) of 268 participants allocated to antiplatelet therapy had recurrence of intracerebral haemorrhage compared with 23 (9%) of 268 participants allocated to avoid antiplatelet therapy (adjusted hazard ratio 0·51 [95% CI 0·25–1·03]; p=0·060). 18 (7%) participants allocated to antiplatelet therapy experienced major haemorrhagic events compared with 25 (9%) participants allocated to avoid antiplatelet therapy (0·71 [0·39–1·30]; p=0·27), and 39 [15%] participants allocated to antiplatelet therapy had major occlusive vascular events compared with 38 [14%] allocated to avoid antiplatelet therapy (1·02 [0·65–1·60]; p=0·92). Interpretation: These results exclude all but a very modest increase in the risk of recurrent intracerebral haemorrhage with antiplatelet therapy for patients on antithrombotic therapy for the prevention of occlusive vascular disease when they developed intracerebral haemorrhage. The risk of recurrent intracerebral haemorrhage is probably too small to exceed the established benefits of antiplatelet therapy for secondary prevention