Social interactions in wild black-fronted titi monkeys (Callicebus nigrifrons)

Social species live in groups that vary in size and composition for many reasons, including resource availability, predation risk, and space restrictions. Their social interactions reflect intraspecific interactions, social bonding, rank, reproductive status, and relatedness. Titi monkeys (Callicebus, Cheracebus, and Plecturocebus) are a diverse group of pitheciid primates that are widely distributed throughout South America. Typically, they live in small groups composed of a breeding pair and their offspring. Although social structure and interactions have been studied in captive titi monkeys, there has been much less research on free-ranging groups. We used all occurrence sampling during a 16-month period to investigate group composition and within-group social interactions in five wild groups of black-fronted titi monkeys, Callicebus nigrifrons living in an Atlantic Forest fragment at the Caraça Private Natural Heritage Reserve in Minas Gerais, Brazil. Unusually for the species, we found more than one adult male in three of our study groups (three adult males in one group and two in the other two groups). As reported for other titi monkeys, the breeding pair interacted more with each other than with any other group members. We also observed that breeding males interacted more with their offspring than breeding females did. Our results expand the existing literature on the social structure of titi monkeys, demonstrating their flexible social organization, providing further evidence of the breeding pair as the nucleus of the group and showing evidence for strong paternal care and stable attachments between breeding pairs in free-ranging C. nigrifrons

Language brokering between deaf signing parents and healthcare professionals:The experience of young hearing people in the UK

Language brokering refers to the informal interpreting performed by children and young people, typically in migrant families. Hearing heritage signers are typically individuals who grow up using a sign language at home with deaf parents. As most of them are hearing, they often broker between their signing deaf parent(s) and hearing non-signers. Brokering has been found to occur in varied contexts, including healthcare settings. Using semi-structured interviews, this study aimed specifically to explore the experiences of hearing heritage signers brokering between their parents and healthcare professionals using British Sign Language.Hearing heritage signers’ experiences of brokering in healthcare settings were found to be varied, as were their attitudes, feelings and views towards brokering. Key themes were identified: pride and pressure; insider and outsider status; conflicting roles; autonomy, dependence and independence; choice and expectation; and perceptions of high- or low-stakes brokering. Based on these findings, recommendations for healthcare providers include increasing awareness of deaf people’s rights and access, recognition of children’s developmental needs in these contexts and the ability to signpost hearing heritage signers to appropriate support networks

Assessment of Projected Extreme Climate Change Impact on The Operational Performance of Surface Water Reservoirs

This study investigated the impacts of the extreme climate change projections on the performance of Lake Hume in southeast Australia. The study utilised the Australian Climate Change Website tools and leveraged publications from reliable sources to project future inflows and demand. The study revealed that the Lake Hume reservoir could withstand extreme wet conditions with an insignificant impact on the downstream environment. Additionally, for these inflow conditions, the simulation results showed that the storage capacity was adequate for meeting the demand with enhanced performance. However, the release exceeded the downstream channel capacity on one occasion, but the impact was insignificant. On the other hand, the modelling of the extreme-dry conditions showed that the reservoir might drain all its stored water almost 53% of the time, with knock-on effects on systems reliability, resilience and vulnerability. Both of these results are expected, but isolating the effects of extreme wet and dry, as done in this study, will assist water managers to better prepare for coping with water security issues. That may arise from extreme weather events, which are now projected to occur more frequently with climate change

Group Equations With Abelian Predicates

In this paper, we begin the systematic study of group equations with abelian predicates in the main classes of groups where solving equations is possible. We extend the line of work on word equations with length constraints, and more generally, on extensions of the existential theory of semigroups, to the world of groups. We use interpretability by equations to establish model-theoretic and algebraic conditions, which are sufficient to get undecidability. We apply our results to (non-abelian) right-angled Artin groups and show that the problem of solving equations with abelian predicates is undecidable for these. We obtain the same result for hyperbolic groups whose abelianisation has torsion-free rank at least two. By contrast, we prove that in groups with finite abelianisation, the problem can be reduced to solving equations with recognisable constraints, and so this is decidable in right-angled Coxeter groups, or more generally, graph products of finite groups, as well as hyperbolic groups with finite abelianisation

Enhancing Student Engagement through Scaffolding Strategy in Active Learning Environment

This paper introduces the implementation of various interactive activities in an active learning environment using the scaffolding strategy, which aims to enhance student engagement in Engineering Mathematics and Statistics course, offered to second year Electrical and Electronic Engineering students. Over the years, students have been struggling to master solving complex engineering problems in the curriculum. The paper suggests that various interactive activities in which course lecturer assumes specific roles, through scaffolding strategy, can enhance students’ ability to acquire skills to analyse fundamental theorems related to probability and information theory, and probability and statistical method for engineering problems. This approach involves lecturer assuming specific role in the designed activities using the scaffolding strategy. This paper explores how this approach can be customized to suit the learning needs in both learning modes; face-to-face (pre-pandemic) and online learning (during pandemic). Data collected was based on students’ performance and course feedback survey. Improved student performance was observed using this scaffolding strategy, which can also be implemented in both in-person and online teaching.</p

Numerical analysis of high-speed railway slab tracks using calibrated and validated 3D time-domain modelling

Concrete slabs are widely used in modern railways to increase the inherent resilient quality of the tracks, provide safe and smooth rides, and reduce the maintenance frequency. In this paper, the elastic performance of a novel slab trackform for high-speed railways is investigated using three-dimensional finite element modelling in Abaqus. It is then compared to the performance of a ballasted track. First, slab and ballasted track models are developed to replicate the full-scale testing of track sections. Once the models are calibrated with the experimental results, the novel slab model is developed and compared against the calibrated slab track results. The slab and ballasted track models are then extended to create linear dynamic models, considering the track geodynamics, and simulating train passages at various speeds, for which the Ledsgård documented case was used to validate the models. Trains travelling at low and high speeds are analysed to investigate the track deflections and the wave propagation in the soil, considering the issues associated with critical speeds. Various train loading methods are discussed, and the most practical approach is retained and described. Moreover, correlations are made between the geotechnical parameters of modern high-speed rail and conventional standards. It is found that considering the same ground condition, the slab track deflections are considerably smaller than those of the ballasted track at high speeds, while they show similar behaviour at low speeds

Investigating the role of hydrological connectivity on the processing of organic carbon in tropical aquatic ecosystems

Inland waters are highways of carbon and nutrient flows between the land and ocean. Aquatic environments integrate multiple sources and processes over space and time that influence ecosystem functionality. The complexity of these systems and their multiple interactions with the surrounding environment are conceptualised, but often lack empirical scrutiny that allows further understanding of how inland waters mobilise, transport, and utilise carbon and nutrients. This is particularly evident in tropical waters. Here, we apply advanced geochemical analyses of dissolved organic matter (DOM) composition in conjunction with algal pigment biomarkers, to determine the seasonal variability of organic matter production, processing and export for a tropical, floodpulse wetland, Tasik Chini (Malaysia). We identify two phases in the hydrological cycle: Phase 1 signifying a transition from the wet season with high suspended sediment and dissolved organic carbon concentrations. DOM is composed of humic substances, building blocks and lower molecular weight compounds. Towards the end this phase then are periods of increased water clarity and algal productivity. This is followed by Phase 2, which has a greater contribution of autochthonous DOM, composed of proteinaceous material, concomitant with lower dissolved nutrient concentrations, increased mixotrophic algae and emergent vegetation. Based on this framework, we highlight the role of such tropical wetland lakes as hydrological “bottlenecks,” through a lentic/lotic switch that shifts aquatic transport of carbon and nutrients from lateral river continuum supply to flood pulses. We highlight the need to consider inherent biases of spatial and temporal scaling when examining freshwater ecosystems along the land-ocean aquatic continuum

On the unique ergodicity for a class of 2 dimensional stochastic wave equations

We study the global-in-time dynamics for a stochastic semilinear wave equation with cubic defocusing nonlinearity and additive noise, posed on the 2-dimensional torus. The noise is taken to be slightly more regular than space-time white noise. In this setting, we show existence and uniqueness of an invariant measure for the Markov semigroup generated by the flow over an appropriately chosen Banach space. This extends a result of the second author [Comm. Math. Phys. 377 (2020), pp. 1311–1347] to a situation where the invariant measure is not explicitly known.</p

A Scoping Review on the Opportunities for Social Engagement and Cognitive Frailty in Older Adults

Cognitive frailty (CF) is defined as the clinical syndrome of the combination of physical frailty and cognitive impairment, without dementia. Numerous risk factors for CF have been previously identified but this scoping review focusses on the critical need for social engagement and the association with cognition. The focus of this scoping review on the opportunity for social engagement rather than on perception or experience of loneliness. Based on the results of 55 studies were synthesised into four social engagement categories, namely participation, household, network, and habitat. Social engagement is associated with maintaining or improving cognition, particularly through active participation in social roles. Habitat (i.e., rural or urban settings) also influences cognition and the challenge is to enable social participation