Influence of physico-chemical and biotic factors on the distribution of a penaeid in a temperate estuary

The distribution, abundance and size structure of a penaeid with tropical affinities (Metapenaeus dalli) was investigated in a temperate, microtidal estuary in south-western Australia. Sampling was conducted every lunar month for two years at 20 sites across five regions (nine subregions) in nearshore waters by hand trawl, and at 16 sites across four regions (eight subregions) in offshore waters by otter trawl. Densities of M. dalli changed markedly seasonally, with greatest values recorded in nearshore waters from October to February, and in offshore waters from March to July. These densities also varied spatially, with the highest recorded in the Lower Canning, Middle Swan, and Upper Melville Water regions. Spearman's rank correlation showed a positive relationship between the density of M. dalli in nearshore waters and surface water temperature in all nine subregions, whilst densities of M. dalli in offshore waters were negatively correlated with bottom water temperature in most of the estuary; these correlations reflect the movement of adult prawns into shallow waters for breeding in summer, as well as the subsequent recruitment and movement back into deeper waters over the winter months. Mean carapace lengths remained relatively unchanged over the late autumn and winter months (May to August), before rapidly increasing with temperature in late spring. The spatial and temporal distribution of M. dalli differed significantly from those of other crustaceans in the estuary, particularly the penaeid Penaeus latisulcatus, which was concentrated mainly in the Lower and Upper Melville Water regions. The distribution of M. dalli was statistically indistinct from that of the apogonid Ostorhinchus rueppellii, which predates heavily on postlarval M. dalli, and very similar to those of two scyphozoans, Aurelia aurita and Phyllorhiza punctata, that likely predate on larval M. dalli. These findings highlight the partitioning of species within the estuary and the significance of site selection for maximising the post-release survival of hatchery-reared M. dalli produced by aquaculture-based enhancement programs

Larval development of the western school prawn Metapenaeus dalli Racek, 1957 (Crustacea: Decapoda: Penaeidae) reared in the laboratory

The six Naupliar, three Protozoea, three Mysis and first post-larval forms of the western school prawn Metapenaeus dalli Racek, 1957 were cultured in the laboratory. These stages were described in detail and compared to those of other metapenaeids. The ontogenetic development occurred in 12 days at 26°C, with both the growth rate and morphological patterns of development in M. dalli broadly following those recorded for other metapenaeids. Differences were found between M. dalli and other metapenaeids at corresponding stages of larval development, with these being the number, location and composition of individual setae and other minor spinal development

Quantitative determination of ovarian development in penaeid prawns (Decapoda: Penaeidae)

We developed histological methods to increase precision in measuring oocyte size and, for the first time, quantify changes in oocyte composition during ovarian development in penaeids. Wild-caught female Metapenaeus dalli Racek, 1957 from the Swan-Canning Estuary, Perth, Western Australia were used as a model species to compare the novel method to traditional techniques. Morphological analysis showed that ovarian development in M. dalli occurs in five stages: immature, early maturing, late maturing, mature, and post spawning, which is consistent with other penaeids. Analysis of key morphometric parameters of length and Gonad Somatic Index (GSI) showed that GSI provided the strongest discriminators of ovarian development. Oogenesis was similar to qualitative descriptions of other penaeid prawns and most-closely related to previous descriptions of Metapenaeus affinis Milne Edwards, 1837. Comparisons between the novel perimeter tracing and traditional single linear methods for measuring oocyte dimensions showed that greater precision was achieved by tracing. This resulted in a 17-40% reduction in the confidence limits of the means for all cell types measured. A novel histological technique of examining oocyte composition was also developed. This technique allowed for the relationship between stages of ovarian development and proportion by volume of oocyte types to be determined. The difference in the proportions of cell types between each stage of ovarian development was found to be statistically significant, except between immature and post spawning females. The novel methods developed in this study provide new opportunities in the study of ovarian development in penaeids and possibly in other species

Restocking of the Western School Prawn (Metapenaeus dalli) in the Swan Canning Riverpark

This report provides the first comprehensive investigation into the biology and ecology of the Western School Prawn (Metapenaeus dalli) in the Swan-Canning Estuary in south-western Australia. It provides knowledge to help manage the fishery and evaluate release strategies for the aquaculture-based enhancement of this species. The study involved Murdoch University, the Department of Biodiversity, Conservation and Attractions (DBCA) (formerly Department of Parks and Wildlife and the Swan River Trust) and the Australian Centre for Applied Aquaculture Research (ACAAR). It was designed to complement a concurrent project to develop aquaculture techniques to produce and release M. dalli and re-engage the local community with prawning and the estuary (led by ACAAR, DBCA’s Parks and Wildlife Service and the West Australian Fish Foundation), funded by the Recreational Fishing Initiatives Fund. The Fisheries Research and Development Corporation provided matching funds for the current study. Biological data on M. dalli were collected from 20 sites in nearshore and 16 in the offshore waters of the Swan-Canning Estuary, ranging from the mouth of the system to ~40 and 30 km upstream in the Swan and Canning rivers, respectively, in every lunar month between October 2013 and March 2016. Laboratory studies were also completed to investigate the survival and growth of larval prawns in different salinity, water temperature and algal food conditions. Results were presented as part of the Prawn Watch program to engage the community in the research and encourage stewardship of the fishery and the estuary

Dust Devil Tracks

Dust devils that leave dark- or light-toned tracks are common on Mars and they can also be found on the Earth’s surface. Dust devil tracks (hereinafter DDTs) are ephemeral surface features with mostly sub-annual lifetimes. Regarding their size, DDT widths can range between ∼1 m and ∼1 km, depending on the diameter of dust devil that created the track, and DDT lengths range from a few tens of meters to several kilometers, limited by the duration and horizontal ground speed of dust devils. DDTs can be classified into three main types based on their morphology and albedo in contrast to their surroundings; all are found on both planets: (a) dark continuous DDTs, (b) dark cycloidal DDTs, and (c) bright DDTs. Dark continuous DDTs are the most common type on Mars. They are characterized by their relatively homogenous and continuous low albedo surface tracks. Based on terrestrial and martian in situ studies, these DDTs most likely form when surficial dust layers are removed to expose larger-grained substrate material (coarse sands of ≥500 μm in diameter). The exposure of larger-grained materials changes the photometric properties of the surface; hence leading to lower albedo tracks because grain size is photometrically inversely proportional to the surface reflectance. However, although not observed so far, compositional differences (i.e., color differences) might also lead to albedo contrasts when dust is removed to expose substrate materials with mineralogical differences. For dark continuous DDTs, albedo drop measurements are around 2.5 % in the wavelength range of 550–850 nm on Mars and around 0.5 % in the wavelength range from 300–1100 nm on Earth. The removal of an equivalent layer thickness around 1 μm is sufficient for the formation of visible dark continuous DDTs on Mars and Earth. The next type of DDTs, dark cycloidal DDTs, are characterized by their low albedo pattern of overlapping scallops. Terrestrial in situ studies imply that they are formed when sand-sized material that is eroded from the outer vortex area of a dust devil is redeposited in annular patterns in the central vortex region. This type of DDT can also be found in on Mars in orbital image data, and although in situ studies are lacking, terrestrial analog studies, laboratory work, and numerical modeling suggest they have the same formation mechanism as those on Earth. Finally, bright DDTs are characterized by their continuous track pattern and high albedo compared to their undisturbed surroundings. They are found on both planets, but to date they have only been analyzed in situ on Earth. Here, the destruction of aggregates of dust, silt and sand by dust devils leads to smooth surfaces in contrast to the undisturbed rough surfaces surrounding the track. The resulting change in photometric properties occurs because the smoother surfaces have a higher reflectance compared to the surrounding rough surface, leading to bright DDTs. On Mars, the destruction of surficial dust-aggregates may also lead to bright DDTs. However, higher reflective surfaces may be produced by other formation mechanisms, such as dust compaction by passing dust devils, as this may also cause changes in photometric properties. On Mars, DDTs in general are found at all elevations and on a global scale, except on the permanent polar caps. DDT maximum areal densities occur during spring and summer in both hemispheres produced by an increase in dust devil activity caused by maximum insolation. Regionally, dust devil densities vary spatially likely controlled by changes in dust cover thicknesses and substrate materials. This variability makes it difficult to infer dust devil activity from DDT frequencies. Furthermore, only a fraction of dust devils leave tracks. However, DDTs can be used as proxies for dust devil lifetimes and wind directions and speeds, and they can also be used to predict lander or rover solar panel clearing events. Overall, the high DDT frequency in many areas on Mars leads to drastic albedo changes that affect large-scale weather patterns

Developing a predictive modelling capacity for a climate change-vulnerable blanket bog habitat: Assessing 1961-1990 baseline relationships

Aim: Understanding the spatial distribution of high priority habitats and developing predictive models using climate and environmental variables to replicate these distributions are desirable conservation goals. The aim of this study was to model and elucidate the contributions of climate and topography to the distribution of a priority blanket bog habitat in Ireland, and to examine how this might inform the development of a climate change predictive capacity for peat-lands in Ireland. Methods: Ten climatic and two topographic variables were recorded for grid cells with a spatial resolution of 1010 km, covering 87% of the mainland land surface of Ireland. Presence-absence data were matched to these variables and generalised linear models (GLMs) fitted to identify the main climatic and terrain predictor variables for occurrence of the habitat. Candidate predictor variables were screened for collinearity, and the accuracy of the final fitted GLM was evaluated using fourfold cross-validation based on the area under the curve (AUC) derived from a receiver operating characteristic (ROC) plot. The GLM predicted habitat occurrence probability maps were mapped against the actual distributions using GIS techniques. Results: Despite the apparent parsimony of the initial GLM using only climatic variables, further testing indicated collinearity among temperature and precipitation variables for example. Subsequent elimination of the collinear variables and inclusion of elevation data produced an excellent performance based on the AUC scores of the final GLM. Mean annual temperature and total mean annual precipitation in combination with elevation range were the most powerful explanatory variable group among those explored for the presence of blanket bog habitat. Main conclusions: The results confirm that this habitat distribution in general can be modelled well using the non-collinear climatic and terrain variables tested at the grid resolution used. Mapping the GLM-predicted distribution to the observed distribution produced useful results in replicating the projected occurrence of the habitat distribution over an extensive area. The methods developed will usefully inform future climate change predictive modelling for Irelan

A novel formulation of inhaled sodium cromoglicate (PA101) in idiopathic pulmonary fibrosis and chronic cough: a randomised, double-blind, proof-of-concept, phase 2 trial

Background Cough can be a debilitating symptom of idiopathic pulmonary fibrosis (IPF) and is difficult to treat. PA101 is a novel formulation of sodium cromoglicate delivered via a high-efficiency eFlow nebuliser that achieves significantly higher drug deposition in the lung compared with the existing formulations. We aimed to test the efficacy and safety of inhaled PA101 in patients with IPF and chronic cough and, to explore the antitussive mechanism of PA101, patients with chronic idiopathic cough (CIC) were also studied. Methods This pilot, proof-of-concept study consisted of a randomised, double-blind, placebo-controlled trial in patients with IPF and chronic cough and a parallel study of similar design in patients with CIC. Participants with IPF and chronic cough recruited from seven centres in the UK and the Netherlands were randomly assigned (1:1, using a computer-generated randomisation schedule) by site staff to receive PA101 (40 mg) or matching placebo three times a day via oral inhalation for 2 weeks, followed by a 2 week washout, and then crossed over to the other arm. Study participants, investigators, study staff, and the sponsor were masked to group assignment until all participants had completed the study. The primary efficacy endpoint was change from baseline in objective daytime cough frequency (from 24 h acoustic recording, Leicester Cough Monitor). The primary efficacy analysis included all participants who received at least one dose of study drug and had at least one post-baseline efficacy measurement. Safety analysis included all those who took at least one dose of study drug. In the second cohort, participants with CIC were randomly assigned in a study across four centres with similar design and endpoints. The study was registered with ClinicalTrials.gov (NCT02412020) and the EU Clinical Trials Register (EudraCT Number 2014-004025-40) and both cohorts are closed to new participants. Findings Between Feb 13, 2015, and Feb 2, 2016, 24 participants with IPF were randomly assigned to treatment groups. 28 participants with CIC were enrolled during the same period and 27 received study treatment. In patients with IPF, PA101 reduced daytime cough frequency by 31·1% at day 14 compared with placebo; daytime cough frequency decreased from a mean 55 (SD 55) coughs per h at baseline to 39 (29) coughs per h at day 14 following treatment with PA101, versus 51 (37) coughs per h at baseline to 52 (40) cough per h following placebo treatment (ratio of least-squares [LS] means 0·67, 95% CI 0·48–0·94, p=0·0241). By contrast, no treatment benefit for PA101 was observed in the CIC cohort; mean reduction of daytime cough frequency at day 14 for PA101 adjusted for placebo was 6·2% (ratio of LS means 1·27, 0·78–2·06, p=0·31). PA101 was well tolerated in both cohorts. The incidence of adverse events was similar between PA101 and placebo treatments, most adverse events were mild in severity, and no severe adverse events or serious adverse events were reported. Interpretation This study suggests that the mechanism of cough in IPF might be disease specific. Inhaled PA101 could be a treatment option for chronic cough in patients with IPF and warrants further investigation

A trans-acting locus regulates an anti-viral expression network and type 1 diabetes risk

Combined analyses of gene networks and DNA sequence variation can provide new insights into the aetiology of common diseases that may not be apparent from genome-wide association studies alone. Recent advances in rat genomics are facilitating systems-genetics approaches. Here we report the use of integrated genome-wide approaches across seven rat tissues to identify gene networks and the loci underlying their regulation. We defined an interferon regulatory factor 7 (IRF7)-driven inflammatory network (IDIN) enriched for viral response genes, which represents a molecular biomarker for macrophages and which was regulated in multiple tissues by a locus on rat chromosome 15q25. We show that Epstein-Barr virus induced gene 2 (Ebi2, also known as Gpr183), which lies at this locus and controls B lymphocyte migration, is expressed in macrophages and regulates the IDIN. The human orthologous locus on chromosome 13q32 controlled the human equivalent of the IDIN, which was conserved in monocytes. IDIN genes were more likely to associate with susceptibility to type 1 diabetes (T1D)-a macrophage-associated autoimmune disease-than randomly selected immune response genes (P = 8.85 x 10(-6)). The human locus controlling the IDIN was associated with the risk of T1D at single nucleotide polymorphism rs9585056 (P = 7.0 x 10(-10); odds ratio, 1.15), which was one of five single nucleotide polymorphisms in this region associated with EBI2 (GPR183) expression. These data implicate IRF7 network genes and their regulatory locus in the pathogenesis of T1D