Social transmission of foraging behaviour in bottlenose dolphins and its interplay with climate change

Cultural behaviour, i.e., that which is transmitted socially among conspecifics, is found in a variety of taxa, including cetaceans. Different methods have been used to detect social learning in animal populations. ‘Network-based diffusion analysis’ (NBDA), for example, provides a statistical frame-work with which the importance of social learning on the spread of a behaviour can be quantified. It infers social learning if the diffusion of behaviour follows the social network and therefore relies on accurate association data among individuals. Incomplete association data can lead to uncertainty over the strengths of connections among individuals. Restricting analyses to only include individuals above a certain threshold of sightings can minimize such uncertainty, but at the same time reduce power of NBDA to detect learning when linking individuals are removed from the network. Following my General Introduction, Chapter 2 of this thesis therefore provides a tool for researchers to select an appropriate threshold for the inclusion of individuals that maximizes the power of NBDA to detect social learning. In the study of the rise and spread of cultural behaviour, ecology and genetics are potentially confounding factors as they too can drive behavioural variation between individuals, communities and populations. I use a multi-network version of NBDA, which can account for these potential confounds by including networks reflecting association patterns, genetic relatedness and habitat use, in Chapters 3 and 4 to investigate the spread of two foraging strategies, ‘shelling’ and ‘sponging’, in a population of Indo-Pacific bottlenose dolphins (Tursiops aduncus) in the western gulf of Shark Bay, Western Australia, between 2007 and 2018. Shelling (Chapter 3) appears to spread horizontally among associated individuals, which stands in stark con-trast to the predominantly vertically transmitted foraging strategies, from mother to offspring, in Shark Bay dolphins and indeed toothed whales in general. My study provides the first quantitative evidence of horizontal transmission in any toothed whale species and suggests similarities in the cultural nature of cetaceans and great apes, which rely extensively on both vertical and horizontal social learning. Conversely, the findings presented in Chapter 4 suggest vertical social transmission of sponging from mother to primarily female offspring, confirming the results of previous research using different methods. Chapters 3 and 4 illustrate how long-term data sets on individual associations, habitat use and genetics, in combination with new statistical tools like NBDA, provide an ideal framework to assess the spread of behaviour in free-ranging animal populations. In Chapter 5, I investigate the impacts of a marine heatwave, which led to catastrophic losses of habitat-forming seagrass beds and mass mortalities of fish and invertebrates in Shark Bay, on the vital rates of the resident dolphin population. Long-term demographic data and capture-recapture analyses on data collected before and after the heatwave indicate immediate and on-going reductions in both survival and reproductive rates within the dolphin population, presumably due to the cascading effects of the heatwave on lower-trophic organisms combined with a lack of ecosystem recovery. Remarkably, survival rates of sponging dolphins appear less adversely impacted compared to those of non-spongers, suggesting that their foraging niche may have buffered them against more negative impacts. Whether or not culturally different communities within a population may respond differently to environmental change remains an exciting avenue of research in the future. Finally, I discuss the broader ramifications of this thesis in the General Discussion and suggest further directions in the study of cultural behaviour in bottlenose dolphins

Contribution of nanoclays to the barrier properties of a model proton exchange membrane for fuel cell application

peer reviewedaudience: researcherDirect methanol fuel cells (DMFCs) that use a proton exchange membrane (PEM) as electrolyte, is a promising alternative source of energy for the future. However, methanol crossover from the anodic side to the cathodic one is a major problem in DMFC. Proper dispersion of layered silicates within the fuel cell membrane has been proposed as a strategy for improving the barrier properties of the membrane. The validity of this approach has been tested in case of a model membrane consisting of phosphotungstic acid doped poly(vinyl alcohol). A solvent casting technique has been used, which allows the nanofiller to be delaminated by an ultrasonic pre-treatment, as confirmed by TEM and XRD analysis. The layered silicates have a favourable impact on the methanol permeability, whose the decrease overcompensates some loss in ionic conductivity

Digital Adoption by an Organization Supporting Informal Caregivers During COVID-19 Pandemic Showing Impact on Service Use, Organizational Performance, and Carers’ Well-Being:Retrospective Population-Based Database Study With Embedded User Survey

Background:The COVID-19 pandemic has catalyzed a move from face-to-face to digital delivery of services by hospitals and primary care. However, little is known about the impact of digital transformation on organizations supporting unpaid caregivers. Since the start of the COVID-19 pandemic, the value of care provided by such informal caregivers is estimated to be £111 billion (US$ 152.7 billion) in England.Objective:This study aims to analyze service uptake patterns (including digital service options) over the pandemic period in an English caregivers’ support organization covering a population of 0.98 million; measure changes in organizational performance, service efficiency, and quality; and identify the views of caregivers on service provision and future digital delivery.Methods:This was a retrospective analysis of the use of digital versus nondigital support services (January 2019 to June 2021) by caregivers in city and rural geographic areas. We compared organizational performance and service quality indicators for 2 financial years (2019-2020 and 2020-2021). A survey was conducted to identify barriers and facilitators to digital service uptake, the computer proficiency of caregivers (the Computer Proficiency Questionnaire, 12-item version), and preferences for future digital service provision. Quantitative data were analyzed using Stata 13 (StataCorp LLC). Thematic analysis was used for open-text survey responses.Results:The number of caregivers registered with the organization rose from 14,817 in 2019 to 20,237 in 2021. Monthly contacts rose from 1929 to 6741, with remote contacts increasing from 48.89% (943/1929) to 86.68% (5843/6741); distinctive patterns were observed for city versus rural caregivers. There was an increase in one-to-one contacts (88.8%) and caregiver assessments (20.9%), with no expansion in staffing. Service quality indicators showed an improvement in 5 of 8 variables (all P<.05). The 152 carers completing the survey had similar demographics to all registered caregivers. The Computer Proficiency Questionnaire, 12-item version, mean score of 25.61 (SD 4.40) indicated relatively high computer proficiency. The analysis of open-text responses identified a preference for the organization to continue to offer face-to-face services as well as web-based options. The digital services that were the most highly rated were carers’ well-being assessments, support needs checks, and peer support groups.Conclusions:Our findings show that staff in the caregiver support organization were agile in adapting their services to digital delivery while dealing with increased numbers of registered clients and higher monthly contacts, all without obvious detriment to service quality. Caregivers indicated a preference for blended services, even while recording high computer proficiency. Considering the economic importance of unpaid caregivers, more attention should be given to organizations funded to provide support for them and to the potential for technology to enhance caregivers’ access to, and engagement with, such services

How do food businesses provide information on allergens in non-prepacked foods? A cross-sectional survey in Switzerland

Purpose This project aimed to investigate allergen information practices of food businesses selling nonprepacked foods after the implementation of the new Swiss food law in May 2017. Methods A cross-sectional telephone survey was conducted with food businesses selling non-prepacked foods in Switzerland. A short, standardised questionnaire was developed in German, based on previous research and literature. It was subsequently translated into French and Italian. Altogether, 882 businesses (restaurants, dairies, butcher shops and bakeries) were contacted, of which 387 were willing to participate. SPSS® (IBM, Armonk, NY, USA) was used for statistical analyses. Results The vast majority (86.0%) of food businesses provides oral allergen information. Only 14.0% currently provide written allergen information to the customer, either upfront or on request. The most frequently used labelling system in written allergen declaration was naming all ingredients (35.2%). A significant number (39.8%) do not place a notice on how to obtain allergen information, although this is a legal requirement in Switzerland when not providing written information upfront. Conclusion So far, not all food businesses have been complying with the new Swiss food law on allergen information of non-prepacked food. Therefore, awareness of the legal obligations around communicating allergen information as well as the verification of its implementation should be enhanced. To meet the needs of consumers and avoid reactions, some form of written allergen information should be promoted. Giving this information on request might encourage communication between customer and staff, thus providing an extra measure of verification

Multi-network-based diffusion analysis reveals vertical cultural transmission of sponge tool use within dolphin matrilines

Behavioural differences among social groups can arise from differing ecological conditions, genetic predispositions and/or social learning. In the past, social learning has typically been inferred as responsible for the spread of behaviour by the exclusion of ecological and genetic factors. This ‘method of exclusion’ was used to infer that ‘sponging’, a foraging behaviour involving tool use in the bottlenose dolphin (Tursiops aduncus) population in Shark Bay, Western Australia, was socially transmitted. However, previous studies were limited in that they never fully accounted for alternative factors, and that social learning, ecology and genetics are not mutually exclusive in causing behavioural variation. Here, we quantified the importance of social learning on the diffusion of sponging, for the first time explicitly accounting for ecological and genetic factors, using a multi-network version of ‘network-based diffusion analysis'. Our results provide compelling support for previous findings that sponging is vertically socially transmitted from mother to (primarily female) offspring. This research illustrates the utility of social network analysis in elucidating the explanatory mechanisms behind the transmission of behaviour in wild animal populations

Multi-network-based diffusion analysis reveals vertical cultural transmission of sponge tool use within dolphin matrilines

Behavioural differences among social groups can arise from differing ecological conditions, genetic predispositions and/or social learning. In the past, social learning has typically been inferred as responsible for the spread of behaviour by the exclusion of ecological and genetic factors. This 'method of exclusion' was used to infer that 'sponging', a foraging behaviour involving tool use in the bottlenose dolphin (Tursiops aduncus) population in Shark Bay, Western Australia, was socially transmitted. However, previous studies were limited in that they never fully accounted for alternative factors, and that social learning, ecology and genetics are not mutually exclusive in causing behavioural variation. Here, we quantified the importance of social learning on the diffusion of sponging, for the first time explicitly accounting for ecological and genetic factors, using a multi-network version of 'network-based diffusion analysis'. Our results provide compelling support for previous findings that sponging is vertically socially transmitted from mother to (primarily female) offspring. This research illustrates the utility of social network analysis in elucidating the explanatory mechanisms behind the transmission of behaviour in wild animal populations

A two-hit mechanism causes cerebral cavernous malformations: complete inactivation of CCM1, CCM2 or CCM3 in affected endothelial cells

Cavernous vascular malformations occur with a frequency of 1:200 and can cause recurrent headaches, seizures and hemorrhagic stroke if located in the brain. Familial cerebral cavernous malformations (CCMs) have been associated with germline mutations in CCM1/KRIT1, CCM2 or CCM3/PDCD10. For each of the three CCM genes, we here show complete localized loss of either CCM1, CCM2 or CCM3 protein expression depending on the inherited mutation. Cavernous but not adjacent normal or reactive endothelial cells of known germline mutation carriers displayed immunohistochemical negativity only for the corresponding CCM protein but not for the two others. In addition to proving loss of function at the protein level, our data are the first to demonstrate endothelial cell mosaicism within cavernous tissues and provide clear pathogenetic evidence that the endothelial cell is the cell of disease origin

Exorcising Grice’s ghost : an empirical approach to studying intentional communication in animals

Language’s intentional nature has been highlighted as a crucial feature distinguishing it from other communication systems. Specifically, language is often thought to depend on highly structured intentional action and mutual mindreading by a communicator and recipient. Whilst similar abilities in animals can shed light on the evolution of intentionality, they remain challenging to detect unambiguously. We revisit animal intentional communication and suggest that progress in identifying analogous capacities has been complicated by (i) the assumption that intentional (that is, voluntary) production of communicative acts requires mental-state attribution, and (ii) variation in approaches investigating communication across sensory modalities. To move forward, we argue that a framework fusing research across modalities and species is required. We structure intentional communication into a series of requirements, each of which can be operationalised, investigated empirically, and must be met for purposive, intentionally communicative acts to be demonstrated. Our unified approach helps elucidate the distribution of animal intentional communication and subsequently serves to clarify what is meant by attributions of intentional communication in animals and humans

Systemic infection modifies the neuroinflammatory response in late stage Alzheimer's disease

Abstract Clinical studies indicate that systemic infections accelerate cognitive decline in Alzheimer’s disease. Animal models suggest that this may be due to enhanced pro-inflammatory changes in the brain. We have performed a post-mortem human study to determine whether systemic infection modifies the neuropathology and in particular, neuroinflammation, in the late-stage of the disease. Sections of cerebral cortex and underlying white matter from controls and Alzheimer's patients who died with or without a terminal systemic infection were immunolabelled and quantified for: (i) Αβ and phosphorylated-tau; (ii) the inflammation-related proteins Iba1, CD68, HLA-DR, FcγRs (CD64, CD32a, CD32b, CD16), CHIL3L1, IL4R and CCR2; and (iii) T-cell marker CD3. In Alzheimer's disease, the synaptic proteins synaptophysin and PSD-95 were quantified by ELISA, and the inflammatory proteins and mRNAs by MesoScale Discovery Multiplex Assays and qPCR, respectively. Systemic infection in Alzheimer's disease was associated with decreased CD16 (p = 0.027, grey matter) and CD68 (p = 0.015, white matter); increased CD64 (p = 0.017, white matter) as well as increased protein expression of IL6 (p = 0.047) and decreased IL5 (p = 0.007), IL7 (p = 0.002), IL12/IL23p40 (p = 0.001), IL15 (p = 0.008), IL16 (p < 0.001) and IL17A (p < 0.001). Increased expression of anti-inflammatory genes CHI3L1 (p = 0.012) and IL4R (p = 0.004) were detected in this group. T-cell recruitment to the brain was reduced when systemic infection was present. However, exposure to systemic infection did not modify the pathology. In Alzheimer's disease, CD68 (p = 0.026), CD64 (p = 0.002), CHI3L1 (p = 0.016), IL4R (p = 0.005) and CCR2 (p = 0.010) were increased independently of systemic infection. Our findings suggest that systemic infections modify neuroinflammatory processes in Alzheimer's disease. However, rather than promoting pro-inflammatory changes, as observed in experimental models, they seem to promote an anti-inflammatory, potentially immunosuppressive, environment in the human brain

Measurement of cortisol in saliva: a comparison of measurement error within and between international academic-research laboratories

Objective: Hundreds of scientific publications are produced annually that involve the measurement of cortisol in saliva. Intra- and inter-laboratory variation in salivary cortisol results has the potential to contribute to cross- study inconsistencies in findings, and the perception that salivary cortisol results are unreliable. This study rigor- ously estimates sources of measurement variability in the assay of salivary cortisol within and between established international academic-based laboratories that specialize in saliva analyses. One hundred young adults (Mean age: 23.10 years; 62 females) donated 2 mL of whole saliva by passive drool. Each sample was split into multiple- 100 µL aliquots and immediately frozen. One aliquot of each of the 100 participants’ saliva was transported to academic laboratories (N = 9) in the United States, Canada, UK, and Germany and assayed for cortisol by the same commercially available immunoassay. Results: 1.76% of the variance in salivary cortisol levels was attributable to differences between duplicate assays of the same sample within laboratories, 7.93% of the variance was associated with differences between laboratories, and 90.31% to differences between samples. In established-qualified laboratories, measurement error of salivary cortisol is minimal, and inter-laboratory differences in measurement are unlikely to have a major influence on the determined values