Ontogenetic changes in the diet of L. forbesi: insights from fatty acid and stable isotope analysis

The diet of L. forbesi in Scottish waters was subject to ontogenetic changes as shown by fatty acid and stable isotope analysis. Crustaceans were more frequently found in stomachs of immature squid smaller than 150 mm mantle length. With increasing size ( > 150 mm) and maturity fish becamemore prominent in the diet. Seasonal differences in the diet were also found but seemed to be linked to seasonal changes in squid size. Prey type and species composition also varied slightly between different regions. Differences between size and region were reflected in fatty acid profiles of mainly the digestive gland tissue. High levels of the saturated fatty acid 16:0 and the polyunsaturated fatty acids 20:5n-3 and 22:6n-3, which are typical for fatty acid signatures of many crustacean species, were found in tissues of smaller immature squid. Higher levels of the monounsaturated fatty acids 16:1n-7, 20:1* and polyunsaturated fatty acids of the linoleic family (C18), which are typical forfish prey species, were found in squid of larger sizes and higher maturity stages. Regional differences found for fatty acid profiles of the digestive gland suggested a significant difference in origin of fatty acids thus indicating different diets. In comparing the fatty acid profiles of squid to those of putative prey species of L. forbesi, it was apparent that gadid species Trisopterus minutus, Micromesistius poutassou and Gadus morhua, were an important component of the diet ofL. forbesi. With increasing size of the predator however the composition of fish species in the diet shifted more towardsGadiculus argenteus, Trachurus trachurus and Sebastes marinus. Results of quantitative fatty acid analysis on the estimate of the contribution of each prey species to the diet also reflected this shift in the importance of different prey species with increasing predator size. Due to slower turnover rates in muscle, changes in carbon and nitrogen stable isotope ratios with diet were more pronounced in this tissue. Smaller squid showed the lowest δ15N ratios thus feeding on the lowest trophic level of all squid examined. δ 13C ratios were the most depleted for small squid indicating that small squid feed on prey closer to the carbon source in the food chain. Stable isotope analysis also showed that squid with fish remains in their stomachs showed higher ratios of nitrogen and less depleted carbon ratios than squid feeding on crustaceans. Comparisons of isotope levels of squid and putative prey species identified blue whiting and silvery pout as putative prey species of bigger sized squid. Small squid seemed to feed on the same trophic level and all other prey species examined were always similar or higher in isotope ratios than squid of any size

Current status of using beaks to identify cephalopods: III International Workshop and training course on Cephalopod beaks, Faial island, Azores, April 2007

The identification of cephalopods using their beaks is still a difficult technique. To increase our knowledge of this technique and stimulate a new generation of beak experts, the III International beak workshop and training course was organized in Faial, Azores Islands in 2007. We briefly review the activities of the workshop, including the identification procedure of lower beaks of cephalopods from predators with emphasis on cetaceans, seals, fish and seabirds; provision of basic knowledge to young researchers interested in the study area; identification of recent developments in beak research; and discussion of the main problematic issues. The families that need particular attention are Brachioteuthidae, Chiroteuthidae, Cranchiidae, Cycloteuthidae, Mastigoteuthidae, Octopoteuthidae, Promachoteuthidae, Onychoteuthidae (particularly the genus Walvisteuthis), Mastigoteuthidae and Cirroteuthidae. The stable isotopic signature of beaks is capable of revealing new trophic relationships and migrations. Future work should focus on: a) obtaining more cephalopod material from research cruises; b) promoting a close and continuous collaboration between beak experts and cephalopod taxonomists and; c) developing new, and updated, beak guides

Close encounters - microplastic availability to pelagic amphipods in sub-antarctic and antarctic surface waters

This study investigated the distribution of plastic debris from the Atlantic portion of the Sub-Antarctic to the Antarctic Peninsula. This region is home to some of the highest concentrations of zooplankton biomass but is also threatened by increasing shipping traffic from fishing and the growing tourism market. Samples were collected using a surface-towed neuston net during the Austral summer 2018, aboard the RRS James Clark Ross. Using Fourier Transform Infrared Spectrometry it was found that 45.6% of the plastic particles isolated from seawater samples were sampling contamination, originating predominantly from the ship. Of the remaining particles, both low density (polyethylene, polypropylene) and high-density (phenoxy and epoxy resins) polymers were found in the surface water suggesting both long-range and local sources of origin. Whilst we found that micro and mesoplastic concentrations in seawater were significantly low (0.013 ± 0.005n/m3) compared to global averages, they were higher along the Antarctic Peninsula than the open ocean (Sub-Antarctic) stations. The potential availability of micro and mesoplastics (MP) to pelagic amphipods was explored, using an observed encounter rate (OER) and a possible encounter rate (PER). The total OER (0.8%) was higher than the PER (0.15%), suggesting that even at low concentrations, microplastics are encountered, and potentially consumed, by amphipods. This study highlights the need to prioritise regions of high zooplankton abundance and to investigate both water and biota to build up a picture of plastic pollution and its potential interaction with the Antarctic Ecosystem

Meta-analysis of effect of nintedanib on reducing FVC decline across interstitial lung diseases

INTRODUCTION: The effect of nintedanib on slowing the rate of decline in forced vital capacity (FVC) has been investigated in randomized placebo-controlled trials in subjects with idiopathic pulmonary fibrosis (IPF), other progressive fibrosing interstitial lung diseases (ILDs), and ILD associated with systemic sclerosis (SSc-ILD). We assessed the consistency of the effect of nintedanib on the rate of decline in FVC over 52 weeks across four placebo-controlled phase III trials. METHODS: We used data on FVC decline from the INPULSIS-1 and INPULSIS-2 trials in subjects with IPF, the INBUILD trial in subjects with progressing fibrosing ILDs other than IPF, and the SENSCIS trial in subjects with SSc-ILD. In each trial, the primary endpoint was the annual rate of decline in FVC (mL/year) assessed over 52 weeks. We performed fixed effect and random effects meta-analyses based on the relative treatment effect of nintedanib versus placebo on the rate of decline in FVC (mL/year) over 52 weeks. Heterogeneity of the relative treatment effect of nintedanib across populations was assessed using the I2 statistic, τ2 and corresponding p value from a Q test for heterogeneity. RESULTS: The combined analysis comprised 1257 subjects treated with nintedanib and 1042 subjects who received placebo. Nintedanib reduced the rate of decline in FVC (mL/year) over 52 weeks by 51.0% (95% CI 39.1, 63.0) compared with placebo. The relative effect (95% CI) was the same using the fixed effect and random effects models. There was no evidence of heterogeneity in the relative treatment effect of nintedanib across the populations studied (I2 = 0%, τ2 = 0, p = 0.93). CONCLUSIONS: A meta-analysis of data from four placebo-controlled trials demonstrated that nintedanib approximately halved the rate of decline in FVC over 52 weeks across subjects with different forms of pulmonary fibrosis, with no evidence of heterogeneity in its relative treatment effect across patient populations

Intra-specific niche partitioning in Antarctic fur seals, Arctocephalus gazella

Competition for resources within a population can lead to niche partitioning between sexes, throughout ontogeny and among individuals, allowing con-specifics to co-exist. We aimed to quantify such partitioning in Antarctic fur seals, Arctocephalus gazella, breeding at South Georgia, which hosts ~95% of the world’s population. Whiskers were collected from 20 adult males and 20 adult females and stable isotope ratios were quantified every 5 mm along the length of each whisker. Nitrogen isotope ratios (δ15N) were used as proxies for trophic position and carbon isotope ratios (δ13C) indicated foraging habitat. Sexual segregation was evident: δ13C values were significantly lower in males than females, indicating males spent more time foraging south of the Polar Front in maritime Antarctica. In males δ13C values declined with age, suggesting males spent more time foraging south throughout ontogeny. In females δ13C values revealed two main foraging strategies: 70% of females spent most time foraging south of the Polar Front and had similar δ15N values to males, while 30% of females spent most time foraging north of the Polar Front and had significantly higher δ15N values. This niche partitioning may relax competition and ultimately elevate population carrying capacity with implications for ecology, evolution and conservation

Effects of nintedanib in patients with idiopathic pulmonary fibrosis by GAP stage

We conducted a post hoc analysis to assess the potential impact of GAP (gender, age, physiology) stage on the treatment effect of nintedanib in patients with idiopathic pulmonary fibrosis. Outcomes were compared in patients at GAP stage I versus II/III at baseline in the INPULSIS\uae trials. At baseline, 500 patients were at GAP stage I (nintedanib 304, placebo 196), 489 were at GAP stage II (nintedanib 296, placebo 193) and 71 were at GAP stage III (nintedanib 38, placebo 33). In nintedanibtreated patients, the annual rate of decline in forced vital capacity (FVC) was similar in patients at GAP stage I and GAP stage II/III at baseline (-110.1 and -116.6 mL.year-1, respectively), and in both subgroups was lower than in placebo-treated patients (-218.5 and -227.6 mL.year-1, respectively) (treatment-by-time-by-subgroup interaction p=0.92). In the nintedanib group, the number of deaths was 43.8% of those predicted based on GAP stage (35 versus 79.9). In the placebo group, the number of deaths was 59.8% of those predicted based on GAP stage (33 versus 55.2). In conclusion, data from the INPULSIS\uae trials suggest that nintedanib has a similar beneficial effect on the rate of FVC decline in patients at GAP stage I versus II/III at baseline

High resolution measurements of carbon monoxide along a late Holocene Greenland ice core: evidence for in situ production

We present high-resolution measurements of carbon monoxide (CO) concentrations from a shallow ice core of the North Greenland Eemian Ice Drilling project (NEEM-2011-S1). An optical-feedback cavity-enhanced absorption spectrometer (OF-CEAS) coupled to a continuous melter system performed continuous, online analysis during a four-week measurement campaign. This analytical setup generated stable measurements of CO concentrations with an external precision of 7.8 ppbv (1σ), based on repeated analyses of equivalent ice core sections. However, this first application of this measurement technique suffered from a poorly constrained procedural blank of 48 ± 25 ppbv and poor accuracy because an absolute calibration was not possible. The NEEM-2011-S1 CO record spans 1800 yr and the long-term trends within the most recent section of this record (i.e., post 1700 AD) resemble the existing discrete CO measurements from the Eurocore ice core. However, the CO concentration is highly variable (75–1327 ppbv range) throughout the ice core with high frequency (annual scale), high amplitude spikes characterizing the record. These CO signals are too abrupt and rapid to reflect atmospheric variability and their prevalence largely prevents interpretation of the record in terms of atmospheric CO variation. The abrupt CO spikes are likely the result of in situ production occurring within the ice itself, although the unlikely possibility of CO production driven by non-photolytic, fast kinetic processes within the continuous melter system cannot be excluded. We observe that 68% of the CO spikes are observed in ice layers enriched with pyrogenic aerosols. Such aerosols, originating from boreal biomass burning emissions, contain organic compounds, which may be oxidized or photodissociated to produce CO within the ice. However, the NEEM-2011-S1 record displays an increase of ~0.05 ppbv yr⁻¹ in baseline CO level prior to 1700 AD (129 m depth) and the concentration remains elevated, even for ice layers depleted in dissolved organic carbon (DOC). Thus, the processes driving the likely in situ production of CO within the NEEM ice may involve multiple, complex chemical pathways not all related to past fire history and require further investigation

Continuous moulting by Antarctic krill drives major pulses of carbon export in the north Scotia Sea, Southern Ocean

Antarctic krill play an important role in biogeochemical cycles and can potentially generate high-particulate organic carbon (POC) fluxes to the deep ocean. They also have an unusual trait of moulting continuously throughout their life-cycle. We determine the krill seasonal contribution to POC flux in terms of faecal pellets (FP), exuviae and carcasses from sediment trap samples collected in the Southern Ocean. We found that krill moulting generated an exuviae flux of similar order to that of FP, together accounting for 87% of an annual POC flux (22.8 g m−2 y−1). Using an inverse modelling approach, we determined the krill population size necessary to generate this flux peaked at 261 g m−2. This study shows the important role of krill exuviae as a vector for POC flux. Since krill moulting cycle depends on temperature, our results highlight the sensitivity of POC flux to rapid regional environmental change