THE BIOENERGETICS AND BEHAVIOUR OF THE RAINBOW TROUT (ONCORHYNCHUS MYKISS) WHEN FEEDING ON A COPPER CONTAMINATED DIET

The long-term effects of sub-lethal dietary Cu-exposure were investigated in relation to consequential energy shifts and resultant locomotory adaptation in 0. mykiss. This study represents the first to attempt to quantify the physiological cost of dietary heavy-metal exposure, the timing and extent of daily behavioural adaptation and resultant significance, in terms of ecologically important behaviours to the fish. Two long-term (2 & 3 months) dietary exposures of 730 mg Cu kgˉ¹ mg d.w. feed showed exposed fish to have a 3-fold increase in liver [Cu] and 10-fold increase in intestinal [Cu] compared to control fish. Consequently exposed fish elicited a detoxification response, and metallothionein production was also greatly increased in these tissues. Cu-uptake was regulated into the body and physiological homeostasis was maintained although a 2-fold increase in lipid peroxidation product was found in the liver of exposed fish. Simultaneous analysis of voluntary spontaneous swimming and VO2. showed exposed fish to have a 1.52 mmol 02 kgˉ¹ hˉ¹ increase over controls, and it was also shown that the cost of routine metabolism became more critical for exposed fish at higher swimming speeds. Although results further showed that the increase in both standard metabolism and routine metabolism over controls by Cu-exposed fish varied greatly between individuals. The increased energetic requirement to remain active when feeding on a Cu-contaminated diet was off-set by a reduction in swimming activity. Growth rates remained indifferent between treatments suggesting that the reduction in activity fully compensated for the increased cost of standard, and routine metabolism in exposed fish. Finite behavioural analyses over the 24-h cycle showed control fish to display periodicity in specific swimming speed, peaking in activity during the night-dawn period. Cu-exposed fish exhibited a different circadian behavioural profile, lacking distinct periodicity in specific swimming speed favouring low-level activity during the night-dawn period, and investing in higher cost swimming activity only during feeding periods. It was suggested that the high swimming activity of control fish during non-feeding periods was associated with inter-individual competition and development of the feeding hierarchy. Direct observation of trout social groups, showed a 50% reduction in the activity of the alpha fish leading to a similarly sized reduction in encounters with subordinates when the group was feeding on a Cu-contaminated diet. Consequently, a general reduction was observed in the strength of the feeding hierarchy, measured as a reduction in the size disparity between individuals within a discrete social group, and a reduction in social stress effects on subordinate fish estimated from lactate accumulation within the muscle. Feeding hierarchies are a result of initial paired interactions, and direct behavioural examination showed that fish feeding on a Cu-contaminated diet were less willing to compete in expensive escalated interactions, favouring withdrawal at a lower level of energetic investment. This lower withdrawal threshold in Cu-exposed fish, was suggested to be related to lower self-assessment of Resource Holding Power (RHP), due to the increased metabolic costs of routine metabolism in Cu-exposed fish, and a reduced resource value of a contaminated diet. The results of this investigation are discussed with regard to energetic decisions undertaken by the fish, associated with the relative costs and benefits of investing energy into growth or activity, to maximise net energy intake (food) when feeding in a social group. And how evaluation of strategies to maximise net energy gain may become more critical in rainbow trout when feeding on a Cu-contarninated diet

Using Environmental DNA to Detect Estuarine Crocodiles, a Cryptic-Ambush Predator of Humans

Negative human–wildlife interactions can be better managed by early detection of the wildlife species involved. However, many animals that pose a threat to humans are highly cryptic, and detecting their presence before the interaction occurs can be challenging. We describe a method whereby the presence of the estuarine crocodile (Crocodylus porosus), a cryptic and potentially dangerous predator of humans, was detected using traces of DNA shed into the water, known as environmental DNA (eDNA). The estuarine crocodile is present in waterways throughout southeast Asia and Oceania and has been responsible for \u3e1,000 attacks upon humans in the past decade. A critical factor in the crocodile’s capability to attack humans is their ability to remain hidden in turbid waters for extended periods, ambushing humans that enter the water or undertake activities around the waterline. In northern Australia, we sampled water from aquariums where crocodiles were present or absent, and we were able to discriminate the presence of estuarine crocodile from the freshwater crocodile (C. johnstoni), a closely related sympatric species that does not pose a threat to humans. Further, we could detect the presence of estuarine crocodiles within an hour of its entry and up to 72 hours after the crocodiles were removed from aquariums. We conclude that eDNA could be a valuable tool for reducing human–wildlife conflict through early detection of the species

Disparities in care and outcomes for primary liver cancer in England during 2008–2018: a cohort study of 8.52 million primary care population using the QResearch database

Background Liver cancer has one of the fastest rising incidence and mortality rates among all cancers in the UK, but it receives little attention. This study aims to understand the disparities in epidemiology and clinical pathways of primary liver cancer and identify the gaps for early detection and diagnosis of liver cancer in England. Methods This study used a dynamic English primary care cohort of 8.52 million individuals aged ≥25 years in the QResearch database during 2008–2018, followed up to June 2021. The crude and age-standardised incidence rates, and the observed survival duration were calculated by sex and three liver cancer subtypes, including hepatocellular carcinoma (HCC), intrahepatic cholangiocarcinoma (CCA), and other specified/unspecified primary liver cancer. Regression models were used to investigate factors associated with an incident diagnosis of liver cancer, emergency presentation, late stage at diagnosis, receiving treatments, and survival duration after diagnosis by subtype. Findings 7331 patients were diagnosed with primary liver cancer during follow-up. The age-standardised incidence rates increased over the study period, particularly for HCC in men (increased by 60%). Age, sex, socioeconomic deprivation, ethnicity, and geographical regions were all significantly associated with liver cancer incidence in the English primary care population. People aged ≥80 years were more likely to be diagnosed through emergency presentation and in late stages, less likely to receive treatments and had poorer survival than those aged <60 years. Men had a higher risk of being diagnosed with liver cancer than women, with a hazard ratio (HR) of 3.9 (95% confidence interval 3.6–4.2) for HCC, 1.2 (1.1–1.3) for CCA, and 1.7 (1.5–2.0) for other specified/unspecified liver cancer. Compared with white British, Asians and Black Africans were more likely to be diagnosed with HCC. Patients with higher socioeconomic deprivation were more likely to be diagnosed through the emergency route. Survival rates were poor overall. Patients diagnosed with HCC had better survival rates (14.5% at 10-year survival, 13.1%–16.0%) compared to CCA (4.4%, 3.4%–5.6%) and other specified/unspecified liver cancer (12.5%, 10.1%–15.2%). For 62.7% of patients with missing/unknown stage in liver cancer, their survival outcomes were between those diagnosed in Stages III and IV. Interpretation This study provides an overview of the current epidemiology and the disparities in clinical pathways of primary liver cancer in England between 2008 and 2018. A complex public health approach is needed to tackle the rapid increase in incidence and the poor survival of liver cancer. Further studies are urgently needed to address the gaps in early detection and diagnosis of liver cancer in England. Funding The Early Detection of Hepatocellular Liver Cancer (DeLIVER) project is funded by Cancer Research UK (Early Detection Programme Award, grant reference: C30358/A29725)

Chapter 13: Permian–Triassic felsic tuffs in South Island, New Zealand: significance for oceanic and active continental margin subduction

Major-element oxide variation plots for the Brook Street Terrane. (a) Fe₂O₃ v. SiO₂; (b) MnO v. SiO₂; (c) MgO v. SiO₂; (d) TiO₂ v. Al₂O₃; (e) TiO₂ v. MgO; (f) Fe₂O₃ v. MgO; (g) MnO v. MgO; (h) CaO v. MgO; (i) K₂O v. MgO. See text and the Supplementary field and petrographic information for explanation