Several neural networks have been proposed in the general literature for pattern recognition and clustering, but little empirical comparison with traditional methods has been done. The results reported here compare neural networks using Kohonen learning with a traditional clustering method (K-means) in an experimental design using simulated data with known cluster solutions. Two types of neural networks were examined, both of which used unsupervised learning to perform the clustering. One used Kohonen learning with a conscience and the other used Kohonen learning without a conscience mechanism. The performance of these nets was examined with respect to changes in the number of attributes, the number of clusters, and the amount of error in the data. Generally, the K-means procedure had fewer points misclassified while the classification accuracy of neural networks worsened as the number of clusters in the data increased from two to five.

A Monte Carlo evaluation of 30 procedures for determining the number of clusters was conducted on artificial data sets which contained either 2, 3, 4, or 5 distinct nonoverlapping clusters. To provide a variety of clustering solutions, the data sets were analyzed by four hierarchical clustering methods. External criterion measures indicated excellent recovery of the true cluster structure by the methods at the correct hierarchy level. Thus, the clustering present in the data was quite strong. The simulation results for the stopping rules revealed a wide range in their ability to determine the correct number of clusters in the data. Several procedures worked fairly well, whereas others performed rather poorly. Thus, the latter group of rules would appear to have little validity, particularly for data sets containing distinct clusters. Applied researchers are urged to select one or more of the better criteria. However, users are cautioned that the performance of some of the criteria may be data dependent.

Developing effective, sustainable strategies that promote social inclusion, reduce isolation, and support older adults’ wellbeing continues to be important to aging communities in Canada. One strategy that targets community-living older adults involves identifying naturally occurring retirement communities (NORCs) and supporting them through supportive service programs (NORC-SSPs). This qualitative descriptive study utilized semi-structured interviews to explore how older adults living in a NORC supported by an SSP, sought to build, and maintain, a sense of community during the COVID-19 pandemic. Analysis revealed how changes in context prompted changes in the program and community, and how despite lack of in-person opportunities participants continued to be together and do occupations together in creative ways that supported their sense of community. NORC-SSPs, like Oasis, play an important role in supporting older adults’ capacity to build strong, resilient communities that support wellbeing, during a global pandemic and in non-pandemic times.

The modern marine megafauna is known to play important ecological roles and includes many charismatic species that have drawn the attention of both the scientific community and the public. However, the extinct marine megafauna has never been assessed as a whole, nor has it been defined in deep time. Here, we review the literature to define and list the species that constitute the extinct marine megafauna, and to explore biological and ecological patterns throughout the Phanerozoic. We propose a size cut-off of 1 m of length to define the extinct marine megafauna. Based on this definition, we list 706 taxa belonging to eight main groups. We found that the extinct marine megafauna was conspicuous over the Phanerozoic and ubiquitous across all geological eras and periods, with the Mesozoic, especially the Cretaceous, having the greatest number of taxa. Marine reptiles include the largest size recorded (21 m; Shonisaurus sikanniensis) and contain the highest number of extinct marine megafaunal taxa. This contrasts with today’s assemblage, where marine animals achieve sizes of >30 m. The extinct marine megafaunal taxa were found to be well-represented in the Paleobiology Database, but not better sampled than their smaller counterparts. Among the extinct marine megafauna, there appears to be an overall increase in body size through time. Most extinct megafaunal taxa were inferred to be macropredators preferentially living in coastal environments. Across the Phanerozoic, megafaunal species had similar extinction risks as smaller species, in stark contrast to modern oceans where the large species are most affected by human perturbations. Our work represents a first step towards a better understanding of the marine megafauna that lived in the geological past. However, more work is required to expand our list of taxa and their traits so that we can obtain a more complete picture of their ecology and evolution.

A model based on Gouy-Chapman theory, describing the ion exchange behavior of clays in mixed electrolyte solutions is presented. Computed ionic distributions, taking into account variations in relative permittivity, ion activity, and closeness of approach of ions to clay surfaces, are compared with experimental data for smectite and kaolinite in contact with river and saline waters. To obtain reasonable agreement between theoretical prediction and observation the most important extension of Gouy-Chapman theory involves the introduction of a closeness of approach term. Furthermore, the aggregated nature of smectites plays an important part in controlling its exchange properties, whereas a fixed-charge model provides a poor description for the ion exchange properties of kaolinite.

The ∼407-myr-old Rhynie chert of Scotland contains exquisite body fossils of land plants, animals and microorganisms, which provide our earliest reasonably complete snapshot of a Phanerozoic terrestrial ecosystem. These fossils have been instrumental to our understanding of the ‘greening of the land’, a major transition in the history of the Earth–life system. Among the primary producers preserved in the chert are cyanobacteria, of which only a fraction have been formally described. Here, we report the occurrence of the colony-forming cyanobacterium Eoentophysalis in the Rhynie chert. To our knowledge, this represents the first bona fide record of Entophysalidaceae from any post-Cambrian fossil assemblage or any non-marine fossil assemblage of any age. The Rhynie Eoentophysalis appears remarkably similar in appearance both to modern marine and freshwater Entophysalis ssp. and to Eoentophysalis belcherensis, a shallow-marine fossil from the ∼2 Ga Belcher Group of Canada that is perhaps the oldest convincing cyanobacterium on record. Darkened cell envelopes in the Rhynie Eoentophysalis correspond well with both E. belcherensis and modern Entophysalis, whose cell envelopes often contain the photoprotective brown pigment scytonemin. The occurrence of Eoentophysalis in the Rhynie chert supports previous claims that the fossilisable traits of entophysalid cyanobacteria are evolutionarily static through geological time. These organisms may be such effective generalists that major changes in their environment – in this case, the transition to a fully non-marine habitat – have not imposed significant selection pressure on these traits.

We present and evaluate the prospects for detecting coherent radio counterparts to gravitational wave (GW) events using Murchison Widefield Array (MWA) triggered observations. The MWA rapid-response system, combined with its buffering mode ($\sim$4 min negative latency), enables us to catch any radio signals produced from seconds prior to hours after a binary neutron star (BNS) merger. The large field of view of the MWA ($\sim$$1\,000\,\textrm{deg}^2$ at 120 MHz) and its location under the high sensitivity sky region of the LIGO-Virgo-KAGRA (LVK) detector network, forecast a high chance of being on-target for a GW event. We consider three observing configurations for the MWA to follow up GW BNS merger events, including a single dipole per tile, the full array, and four sub-arrays. We then perform a population synthesis of BNS systems to predict the radio detectable fraction of GW events using these configurations. We find that the configuration with four sub-arrays is the best compromise between sky coverage and sensitivity as it is capable of placing meaningful constraints on the radio emission from 12.6% of GW BNS detections. Based on the timescales of four BNS merger coherent radio emission models, we propose an observing strategy that involves triggering the buffering mode to target coherent signals emitted prior to, during or shortly following the merger, which is then followed by continued recording for up to three hours to target later time post-merger emission. We expect MWA to trigger on $\sim$$5-22$ BNS merger events during the LVK O4 observing run, which could potentially result in two detections of predicted coherent emission.

Early environmental experience can have significant effects on an animal's ability to adapt to challenges in later life. Prior experience of specific situations may facilitate the development of behavioural skills which can be applied in similar situations to later life. In addition, exposure to a more complex environment may enhance cognitive development (eg increased synaptic density), which can then speed the acquisition of new behavioural responses when faced with novel challenges (Grandin 1989).

Stereotypic behaviour is generally associated with animals maintained in restrictive environments, and has rarely been described in wild or free-ranging animals. The difference between captive and wild populations may be due to their genetic predisposition or to experience of environmental factors. To investigate genetic and environmental factors, we compared the behaviour of 12 wild caught voles and their 9 pups with that of 12 laboratory reared voles and 14 laboratory bred pups. All voles were observed twice. Adults were observed after 10 days housing in a cage, containing food, water, sawdust and hay, and again after 60 days. Pups were observed in the same cages 10 and 60 days after weaning. For each observation, the voles’ behaviour was recorded both undisturbed in this cage, and following introduction to an unfamiliar cage. Locomotor stereotypies were observed in laboratory adults, but not in wild caught voles, which spent less time on all locomotor activities and more time under cover than laboratory voles. There was no difference in mortality or fecundity of laboratory and wild caught voles, so there appeared to be no selective advantage to stereotyping. There was no difference in the behaviour of wild and laboratory pups, so early environmental experience of the cage environment, rather than parental background, was an important factor in the development of locomotor stereotypies in this species. Pups that developed stereotypies by 60 days spent less time under cover and more time walking and climbing after 10 days than voles that did not develop stereotypic behaviour. Stereotypic behaviour may therefore have been derived from persistence of locomotor behaviour. Wild caught voles may have failed to develop locomotor stereotypies, either because they did not perform a locomotor response to captivity or because older voles are less prone to develop novel responses to external cues. It would, therefore, be dangerous to use the absence of stereotypic behaviour as a reliable indicator of welfare without taking into account the animal's prior experience.

Twelve Isa Brown hens (Gallus gallus domesticus) were trained to open a locked door for access to a pen containing an enclosed nest box (‘nest test’) and to return to a home pen containing food, water, litter and a perch (‘home test’). The door was connected to a computer-controlled load cell, which recorded work exerted on the door and unlocked the door when the hen had exceeded a predetermined workload. Following training, the workload was set at 10 Ns, and hens received one nest test per day at 80, 60, 40 or 20 min prior to oviposition, and then one home test per day after 1, 2, 3 or 4 h confinement in the nest pen. As oviposition approached, hens showed a higher work-rate for access to the nest pen, showed a shorter latency to use the nest box and spent a greater proportion of their visit time in the nest box. Hens also worked harder for the home pen, showed a lower latency to feed and spent more time feeding after their return as period of confinement increased. The hens’ work-rate for the nest pen at 40 min prior to oviposition was comparable with their work-rate for the home pen after 4 h confinement, while their work-rate was at its highest in nest tests at 20 min prior to oviposition. The technique appears to be a valid means of assessing the importance of environmental resources, the values of which vary with time. The results suggest that hens place a higher value on gaining access to a discrete nest-site prior to oviposition than they do on gaining access to food following 4 h food deprivation.

Most farm assurance schemes in the UK at least, in part, aim to provide assurances to consumers and retailers of compliance with welfare standards. Inclusion of welfare outcome assessments into the relevant inspection procedures provides a mechanism to improve animal welfare within assurance schemes. In this study, taking laying hens as an example, we describe a process for dealing with the practical difficulties in achieving this in two UK schemes; Freedom Food and Soil Association. The key challenges arise from selecting the most appropriate measures, defining sampling strategies that are feasible and robust, ensuring assessors can deliver a consistent evaluation and establishing a mechanism to achieve positive change. After a consultation exercise and pilot study, five measures (feather cover, cleanliness, aggressive behaviour, management of sick or injured birds, and beak trimming) were included within the inspection procedures of the schemes. The chosen sampling strategy of assessing 50 birds without handling provided reasonable certainty at a scheme level but less certainty at an individual farm level. Despite the inherent limitations within a time and cost sensitive certification assessment, the approach adopted does provide a foundation for welfare improvement by being able to highlight areas of concern requiring attention, enabling schemes to promote the use of outcome scoring as a management tool, promoting the dissemination of relevant technical information in a timely manner and increasing the scrutiny of standards important for the welfare of the birds.

This paper describes a case example where initiatives from private assurance schemes, scientists, charities, government and egg companies have improved the welfare of UK cage-free laying hens. The RSPCA and Soil Association farm assurance schemes introduced formal welfare outcome assessment into their annual audits of laying-hen farms in 2011. Feather loss was assessed on 50 birds from each flock on a three-point scale for two body regions: Head and Neck (HN) and Back and Vent (BV). In support of the observations, assessors were trained in feedback techniques designed to encourage change in farmer behaviour to improve welfare. In addition, during Year 2 farmers were asked about changes they had made, and intended to make on their farms. During 2011-2013 there were also wider industry initiatives to improve feather cover. Data were analysed from 830 and 743 farms in Year 1 and Year 2, respectively. From Year 1 to Year 2 there was a significant reduction in the prevalence of feather loss from 31.8% (9.6% severe) to 20.8% (6% severe) for the HN region, and from 33.1% (12.6% severe) to 22.7% (8.3% severe) for BV. Fifty-nine percent of 662 farmers reported they had made changes on their farms during Year 1 to improve bird welfare. For such a substantial industry change, attributing causation to specific initiatives is difficult; however, this is the first study to demonstrate the value to animal welfare of certification schemes monitoring the effectiveness of their own and other industry-led interventions to guide future policy.

The production of meltwater from glacier ice, which is exposed at the margins of land ice during the summer, is responsible for a large proportion of glacier mass loss. The rate of meltwater production from glacier ice is especially sensitive to its physical structure and chemical composition which combine to determine the albedo of glacier ice. However, the optical properties of near-surface glacier ice are not well known since most prior work has focused on laboratory-grown ice or deep cores. Here, we demonstrate a measurement technique based on diffuse propagation of nanosecond-duration laser pulses in near-surface glacier ice that enables the independent measurement of the scattering and absorption coefficients, allowing for a complete description of the processes governing radiative transfer. We employ a photon-counting detector to overcome the high losses associated with diffuse optics. The instrument is highly portable and rugged, making it optimally suited for deployment in remote regions. A set of measurements taken on Crook and Collier Glaciers, Oregon, serves as a demonstration of the technique. These measurements provide insight into both physical structure and composition of near-surface glacier ice and open new avenues for the analysis of light-absorbing impurities and remote sensing of the cryosphere.