An Epidemiological Investigation of the Re-Emergence of Pancreas Disease in Irish Farmed Atlantic Salmon (Salmo salar L.) in 2002

In the early 1990’s pancreas disease (PD) was shown to be the most significant cause of mortality in Irish farmed salmon (Wheatley et al., 1995, Menzies et al., 1996, Crockford et al., 1999). At that time the aetiology of PD was uncertain but in 1995 it was conclusively shown that PD was caused by a virus subsequently named salmon pancreas disease virus (SPDV), (Nelson et al., 1995, McLoughlin et al., 1996). It has since been further classified and named salmonid alphavirus (Weston et al., 1999, Weston et al., 2002). The clinical and histopathological features of naturally occurring pancreas disease in farmed Atlantic salmon in Ireland were described by Murphy et al., 1992 and McLoughlin et al., 2002. The original epidemiological studies of PD in Ireland indicated that mortality rates up to 48% have occurred in farmed Atlantic salmon in their first year in the sea on some individual fish farms (Menzies et al., 1996). PD was recorded in over 70% of marine sites monitored and the majority of PD outbreaks occurred during August to October (Crockford et al., 1999). A serological survey for the presence of SPDV antibody in 1996 revealed 53% of the sites (9/17) were positive and that not all positive sites had recognised clinical signs of PD. This indicated a relatively low incidence and severity of PD at that time (McLoughlin et al., 1998). This pattern persisted until 2002 when there was a serious increase in both the incidence and severity of PD reported on farmed Atlantic salmon marine sites in Ireland. In order to identify factors associated with this re-emergence of PD in Irish farmed salmon, an in-depth epidemiological investigation was carried out on all marine sites. In trying to identify the cause of a disease from epidemiological studies the concept of time, place and individual is paramount, i.e. why did a particular disease occur in a particular animal or group of animals at a particular time in a particular place? Epidemiological study designs are chosen so that predictor variables are measured in affected and non-affected “units”. These “units” may be cells, animals, pens, farms or countries. The association between these predictor variables and disease is then examined. Where associations are demonstrated then risk factors for disease can be identified. A risk factor is a predictor variable associated with the disease. However the identification of a risk factor does not imply causation. The strength, consistency, temporality and dose response effect of the risk factor add weight to it being causal but only an intervention study where the risk factor is added or omitted can confirm this. Individual or univariate analysis of the relationship between a predictor variable and disease may result in an association being demonstrated. However it is dangerous to read too much into univariate analyses as factors which have been ignored, not measured or not seen as important may have a confounding effect. Multivariate analysis is used to try to provide estimates of association adjusted for the effect of confounding factors is a much more accurate and powerful epidemiological tool, but was of limited application in this snapshot survey of a single production cycle. This report aims to describe the occurrence and severity of PD in Irish farmed salmon in 2002-2003 and to identify risk factors associated with the re-emergence of severe PD. Finally, recommendations are made on how PD can be managed to reduce its serious impact on the health, welfare and productivity of Irish farmed salmon.Funder: Marine Institut

Observational Evidence Against Long-Lived Spiral Arms in Galaxies

We test whether the spiral patterns apparent in many large disk galaxies should be thought of as dynamical features that are stationary in a co-rotating frame for > t_{dyn}, as implied by the density wave approach for explaining spiral arms. If such spiral arms have enhanced star formation (SF), observational tracers for different stages of the SF sequence should show a spatial ordering, from up-stream to downstream in the corotating frame: dense HI, CO, tracing molecular hydrogen gas, 24 micron emission tracing enshrouded SF and UV emission tracing unobscured young stars. We argue that such a spatial ordering should be reflected in the angular cross-correlation (CC, in polar coordinates) using all azimuthal positions among pairs of these tracers; the peak of the CC should be offset from zero, in different directions inside and outside the corotation radius. Recent spiral SF simulations by Dobbs & Pringle, show explicitly that for the case of a stationary spiral arm potential such angular offsets between gas and young stars of differing ages should be observable as cross-correlation offsets. We calculate the angular cross-correlations for different observational SF sequence tracers in 12 nearby spiral galaxies, drawing on a data set with high quality maps of the neutral gas HI, THINGS), molecular gas (CO, HERACLES) along with 24 micron emission (Spitzer, SINGS); we include FUV images (GALEX) and 3.6 $\mu$m emission (Spitzer, IRAC) for some galaxies, tracing aging stars and longer timescales. In none of the resulting tracer cross-correlations for this sample do we find systematic angular offsets, which would be expected for a stationary dynamical spiral pattern of well-defined pattern speed. This result indicates that spiral density waves in their simplest form are not an important aspect of explaining spirals in large disk galaxies.Comment: 13 pages, 16 figure

Cold Dust but Warm Gas in the Unusual Elliptical Galaxy NGC 4125

Data from the Herschel Space Observatory have revealed an unusual elliptical galaxy, NGC 4125, which has strong and extended submillimeter emission from cold dust but only very strict upper limits to its CO and Hi emission. Depending on the dust emissivity, the total dust mass is 2-5 x 10(6) M-circle dot. While the neutral gas-to-dust mass ratio is extremely low (= 10(4) K faster than the dust is evaporated. If galaxies like NGC 4125, where the far-infrared emission does not trace neutral gas in the usual manner, are common at higher redshift, this could have significant implications for our understanding of high redshift galaxies and galaxy evolution.Canadian Space AgencyNatural Sciences and Engineering Research Council of CanadaAgenzia Spaziale Italiana (ASI) I/005/11/0BMVIT (Austria)ESA-PRODEX (Belgium)CEA/CNES (France)DLR (Germany)ASI/INAF (Italy)CICYT/MCYT (Spain)CSA (Canada)NAOC (China)CEA, (France)CNES (France)CNRS (France)ASI (Italy)MCINN (Spain)SNSB (Sweden)STFC (UK)NASA (USA)National Aeronautics and Space AdministrationAstronom

Insights into gas heating and cooling in the disc of NGC 891 from Herschel far-infrared spectroscopy

We present Herschel PACS and SPIRE spectroscopy of the most important far-infrared cooling lines in the nearby edge-on spiral galaxy, NGC 891: [CII] 158 $\mu$m, [NII] 122, 205 $\mu$m, [OI] 63, 145 $\mu$m, and [OIII] 88 $\mu$m. We find that the photoelectric heating efficiency of the gas, traced via the ([CII]+[OII]63)/$F_{\mathrm{TIR}}$ ratio, varies from a mean of 3.5$\times$10$^{-3}$ in the centre up to 8$\times$10$^{-3}$ at increasing radial and vertical distances in the disc. A decrease in ([CII]+[OII]63)/$F_{\mathrm{TIR}}$ but constant ([CII]+[OI]63)/$F_{\mathrm{PAH}}$ with increasing FIR colour suggests that polycyclic aromatic hydrocarbons (PAHs) may become important for gas heating in the central regions. We compare the observed flux of the FIR cooling lines and total IR emission with the predicted flux from a PDR model to determine the gas density, surface temperature and the strength of the incident far-ultraviolet (FUV) radiation field, $G_{0}$. Resolving details on physical scales of ~0.6 kpc, a pixel-by-pixel analysis reveals that the majority of the PDRs in NGC 891's disc have hydrogen densities of 1 < log ($n$/cm$^{-3}$) < 3.5 experiencing an incident FUV radiation field with strengths of 1.7 < log $G_0$ < 3. Although these values we derive for most of the disc are consistent with the gas properties found in PDRs in the spiral arms and inter-arm regions of M51, observed radial trends in $n$ and $G_0$ are shown to be sensitive to varying optical thickness in the lines, demonstrating the importance of accurately accounting for optical depth effects when interpreting observations of high inclination systems. With an empirical relationship between the MIPS 24 $\mu$m and [NII] 205 $\mu$m emission, we estimate an enhancement of the FUV radiation field strength in the far north-eastern side of the disc.Comment: Accepted for publication in A&A. 25 pages, including 17 figures and 3 tables, abstract abridged for arXi

Regional Variations in the Dense Gas Heating and Cooling in M51 from Herschel Far-infrared Spectroscopy

We present Herschel PACS and SPIRE spectroscopy of the most important far-infrared cooling lines in M51, [C II](158 μm), [N II](122 and 205 μm), [O I](63 and 145 μm), and [O III](88 μm). We compare the observed flux of these lines with the predicted flux from a photon-dominated region model to determine characteristics of the cold gas such as density, temperature, and the far-ultraviolet (FUV) radiation field, G_0, resolving details on physical scales of roughly 600 pc. We find an average [C II]/F_(TIR) of 4 × 10^(–3), in agreement with previous studies of other galaxies. A pixel-by-pixel analysis of four distinct regions of M51 shows a radially decreasing trend in both the FUV radiation field, G_0, and the hydrogen density, n, peaking in the nucleus of the galaxy, and then falling off out to the arm and interarm regions. We see for the first time that the FUV flux and gas density are similar in the differing environments of the arm and interarm regions, suggesting that the inherent physical properties of the molecular clouds in both regions are essentially the same

Star formation towards the Scutum tangent region and the effects of Galactic environment

By positional matching to the catalogue of Galactic Ring Survey molecular clouds, we have derived distances to 793 Bolocam Galactic Plane Survey (BGPS) sources out of a possible 806 located within the region defined by Galactic longitudes l = 28.5 degr to 31.5 degr and latitudes |b| < 1 degr. This section of the Galactic Plane contains several major features of Galactic structure at different distances, mainly mid-arm sections of the Perseus and Sagittarius spiral arms and the tangent of the Scutum-Centarus arm, which is coincident with the end of the Galactic Long Bar. By utilising the catalogued cloud distances plus new kinematic distance determinations, we are able to separate the dense BGPS clumps into these three main line-of-sight components to look for variations in star-formation properties that might be related to the different Galactic environments. We find no evidence of any difference in either the clump mass function or the average clump formation efficiency (CFE) between these components that might be attributed to environmental effects on scales comparable to Galactic-structure features. Despite having a very high star-formation rate, and containing at least one cloud with a very high CFE, the star formation associated with the Scutum-Centarus tangent does not appear to be in any way abnormal or different to that in the other two spiral-arm sections. Large variations in the CFE are found on the scale of individual clouds, however, which may be due to local triggering agents as opposed to the large-scale Galactic structure.Comment: 11 pages, 8 figures. Accepted for publication in the Monthly Notices of the Royal Astronomical Societ

Research on Pancreas Disease in Irish Farmed Salmon 2004/2005 – Current and Future Initiatives

Pancreas Disease is the most significant single infectious disease affecting marine salmon farms in Ireland. The first epidemiological studies of Pancreas Disease (PD) in Ireland in the early 1990’s indicated that significant losses occurred in farmed Atlantic salmon in their first year at sea on some individual farms (Menzies et al., 1996). A serological survey for the presence of Salmon Pancreas Disease Virus (SPDV) antibody in 1996 revealed that 53% of Irish sites were positive, but that not all positive sites had recognised clinical signs of PD. This indicated a relatively low incidence and severity of PD at that time (McLoughlin et al., 1998) and this pattern persisted throughout the remainder of the 1990’s. In 2002, a serious increase in both the incidence and severity of PD was reported on farmed Atlantic salmon marine sites in Ireland. An epidemiological survey of Irish sites for 2002 revealed that 59% of sites reported an outbreak of PD, with mortalities averaging 12% (range 1 – 42%; McLoughlin et al., 2003). A recent study using data collected for 2003 and 2004 indicated that PD occurred in 62% and 86% of sites respectively. The average mortality due to PD on affected farms was 18.8% in 2003 and 14.8% in 2004. In response to these significant losses due to PD a range of research initiatives was launched in Ireland and was supported by the Marine Institute. This document gives an overview of the most recent findings from the current projects, carried out in 2004/2005 and also provides an overview of the various actions in Scotland and Norway, where PD has also become a disease of economic significance in salmon aquaculture.Funder: Marine Institut

Mapping the cold dust temperatures and masses of nearby Kingfish galaxies with Herschel

Taking advantage of the sensitivity and angular resolution of the Herschel Space Observatory at far-infrared and submm wavelengths, we aim to characterize the physical properties of cold dust within nearby galaxies and study the robustness of the parameters we derive using different modified blackbody models. For a pilot subsample of the KINGFISH program, we perform 2 temperature fits of the Spitzer and Herschel photometric data (24 to 500um), with a warm and a cold component, globally and in each resolution element.At global scales, we observe ranges of values for beta_c(0.8 to 2.5) and Tc(19.1 to 25.1K).We compute maps of our parameters with beta fixed or free to test the robustness of the temperature and dust surface density maps we deduce. When the emissivity is fixed, we observe temperature gradients as a function of radius.When the emissivity is fitted as a free parameter, barred galaxies tend to have uniform fitted emissivities.Gathering resolved elements in a Tc-beta_c diagram underlines an anti-correlation between the two parameters.It remains difficult to assess whether the dominant effect is the physics of dust grains, noise, or mixing along the line of sight and in the beam. We finally observe in both cases that the dust column density peaks in central regions of galaxies and bar ends (coinciding with molecular gas density enhancements usually found in these locations).We also quantify how the total dust mass varies with our assumptions about the emissivity index as well as the influence of the wavelength coverage used in the fits. We show that modified blackbody fits using a shallow emissivity (beta_c < 2.0) lead to significantly lower dust masses compared to the beta_c < 2.0 case, with dust masses lower by up to 50% if beta_c=1.5 for instance.The working resolution affects our total dust mass estimates: masses increase from global fits to spatially-resolved fits.Comment: 26 pages, 12 figures, 4 tables, accepted for publication in MNRAS, 2012 June 2

Uplifting manhood to wonderful heights? News coverage of the human costs of military conflict from world war I to Gulf war Two

Domestic political support is an important factor constraining the use of American military power around the world. Although the dynamics of war support are thought to reflect a cost-benefit calculus, with costs represented by numbers of friendly war deaths, no previous study has examined how information about friendly, enemy, and civilian casualties is routinely presented to domestic audiences. This paper establishes a baseline measure of historical casualty reporting by examining New York Times coverage of five major wars that occurred over the past century. Despite important between-war differences in the scale of casualties, the use of conscription, the type of warfare, and the use of censorship, the frequency of casualty reporting and the framing of casualty reports has remained fairly consistent over the past 100 years. Casualties are rarely mentioned in American war coverage. When casualties are reported, it is often in ways that minimize or downplay the human costs of war

Synergy between EngE, XynA and ManA from Clostridium cellulovorans on corn stalk, grass and pineapple pulp substrates

The synergistic interaction between various hemi/cellulolytic enzymes has become more important in order to achieve effective and optimal degradation of complex lignocellulose substrates for biofuel production. This study investigated the synergistic effect of three enzymes endoglucanase (EngE), mannanase (ManA) and xylanase (XynA) on the degradation of corn stalk, grass, and pineapple fruit pulp and determined the optimal degree of synergy between combinations of these enzymes. It was established that EngE was essential for degradation of all of the substrates, while the hemicellulases were able to contribute in a synergistic fashion to increase the activity on these substrates. Maximum specific activity and degree of synergy on the corn stalk and grass was found with EngE:XynA in a ratio of 75:25%, with a specific activity of 41.1 U/mg protein and a degree of synergy of 6.3 for corn stalk, and 44.1 U/mg protein and 3.4 for grass, respectively. The pineapple fruit pulp was optimally digested using a ManA:EngE combination in a 50:50% ratio; the specific activity and degree of synergy achieved were 52.4 U/mg protein and 2.7, respectively. This study highlights the importance of hemicellulases for the synergistic degradation of complex lignocellulose. The inclusion of a mannanase in an enzyme consortium for biomass degradation should be examined further as this study suggests that it may play an important, although mostly overlooked, role in the synergistic saccharification of lignocellulose