Monitoring riverine fish communities through eDNA metabarcoding:Determining optimal sampling strategies along an altitudinal and biodiversity gradient

Monitoring aquatic biodiversity through DNA extracted from environmental samples (eDNA) combined with high-throughput sequencing, commonly referred to as eDNA metabarcoding, is increasing in popularity within the scientific community. However, sampling strategies, laboratory protocols and analytical pipelines can influence the results of eDNA metabarcoding surveys. While the impact of laboratory protocols and analytical pipelines have been extensively studied, the importance of sampling strategies on eDNA metabarcoding surveys has not received the same attention. To avoid underestimating local biodiversity, adequate sampling strategies (i.e. sampling intensity and spatial sampling replication) need to be implemented. This study evaluated the impact of sampling strategies along an altitudinal and biodiversity gradient in the upper section of the Murrumbidgee River (Murray-Darling Basin, Australia). An eDNA metabarcoding survey was used to determine the local fish biodiversity and evaluate the influence of sampling intensity and spatial sampling replication on the biodiversity estimates. The results show that optimal eDNA sampling strategies varied between sites and indicate that river morphology, species richness and species abundance affect the optimal sampling intensity and spatial sampling replication needed to accurately assess the fish biodiversity. While the generality of the patterns will need to be confirmed through future studies, these findings provide a basis to guide future eDNA metabarcoding surveys in river systems

Monitoring aquatic plants: An evaluation of hydroacoustic, on-site digitising and airborne remote sensing techniques

Aquatic macrophytes are often monitored to detect change in ecosystem function and state, as well as assessing the effectiveness of invasive aquatic plant management. This study compares seven methodologies to monitor the distribution and abundances of aquatic macrophytes. Four line transect methodologies and three spatial mapping techniques were employed in parallel over a broad turbidity gradient in two lentic habitats of south-eastern Australia. The methodologies examined included hydroacoustic surveys, on-site digitising, and digitisation of airborne remote sensing imagery. Variation in estimates of macrophyte coverage were observed between methodologies. Consistency in the collection and interpretation of data was greatest for the line transect methodologies and the digitisation of satellite imagery. Duel-frequency identification sonar proved to be an effective novel hydroacoustic technique to monitor macrophyte abundances over broad spatial scales. Single beam sonar transects was also an objective, repeatable and scalable methodology. Videography and on-site handheld PDA mapping were of limited utility due to restrictions imposed by turbidity. The utility of sidescan sonar could be improved when used in conjunction with on-site handheld PDA mapping. This study outlines important considerations when selecting a methodology to monitor macrophyte distribution and abundance. Results indicate that no one specific method can be employed across all macrophyte monitoring studies. The method or combination of methods employed during macrophyte monitoring studies is dependent upon the study objectives, budget and environmental conditions of the study site

Physical and emotional nourishment: Food as the embodied component of loving care of elderly family relatives

Purpose This purpose of this study is to examine the fluidity of family life which continues to attract attention. This is increasingly significant for the intergenerational relationship between adult children and their elderly parents. Using practice theory, the aims are to understand the role of food in elderly families and explore how family practices are maintained when elderly transition into care. Design/methodology/approach A phenomenological research approach was used as the authors sought to build an understanding of the social interactions between family and their lifeworld. Findings This study extends theory on the relationship between the elderly parent and their family and explores through practice theory how families performed their love, how altered routines and long standing rituals provided structure to the elderly relatives and how care practices were negotiated as the elderly relatives transitioned from independence to dependence and towards care. A theoretical framework is introduced that provides guidance for the transition stages and the areas for negotiation. Research limitations/implications This research has implications for food manufacturers and marketers, as the demand for healthy food for the elderly is made more widely available, healthy and easy to prepare. The limitations of the research are due to the sample located in East Yorkshire only. Practical implications This research has implications for brand managers of food manufacturers and supermarkets that need to create product lines that target this segment by producing healthy, convenience food. Social implications It is also important for health and social care policy as the authors seek to understand the role of food, family and community and how policy can be devised to provide stability in this transitional and uncertain lifestage. Originality/value This research extends the body of literature on food and the family by focussing on the elderly cared for and their family. The authors show how food can be construed as loving care, and using practice theory, a theoretical framework is developed that can explain the transitions and how the family negotiates the stages from independence to dependence

Physical and emotional nourishment: Food as the embodied component of loving care of elderly family relatives

Purpose This purpose of this study is to examine the fluidity of family life which continues to attract attention. This is increasingly significant for the intergenerational relationship between adult children and their elderly parents. Using practice theory, the aims are to understand the role of food in elderly families and explore how family practices are maintained when elderly transition into care. Design/methodology/approach A phenomenological research approach was used as the authors sought to build an understanding of the social interactions between family and their lifeworld. Findings This study extends theory on the relationship between the elderly parent and their family and explores through practice theory how families performed their love, how altered routines and long standing rituals provided structure to the elderly relatives and how care practices were negotiated as the elderly relatives transitioned from independence to dependence and towards care. A theoretical framework is introduced that provides guidance for the transition stages and the areas for negotiation. Research limitations/implications This research has implications for food manufacturers and marketers, as the demand for healthy food for the elderly is made more widely available, healthy and easy to prepare. The limitations of the research are due to the sample located in East Yorkshire only. Practical implications This research has implications for brand managers of food manufacturers and supermarkets that need to create product lines that target this segment by producing healthy, convenience food. Social implications It is also important for health and social care policy as the authors seek to understand the role of food, family and community and how policy can be devised to provide stability in this transitional and uncertain lifestage. Originality/value This research extends the body of literature on food and the family by focussing on the elderly cared for and their family. The authors show how food can be construed as loving care, and using practice theory, a theoretical framework is developed that can explain the transitions and how the family negotiates the stages from independence to dependence

Favouritism: exploring the 'uncontrolled' spaces of the leadership experience

In this paper, we argue that a focus on favouritism magnifies a central ethical ambiguity in leadership, both conceptually and in practice. The social process of favouritism can even go unnoticed, or misrecognised if it does not manifest in a form in which it can be either included or excluded from what is (collectively interpreted as) leadership. The leadership literature presents a tension between what is an embodied and relational account of the ethical, on the one hand, and a more dispassionate organisational ‘justice’ emphasis, on the other hand. We conducted 23 semi-structured interviews in eight consultancy companies, four multinationals and four internationals. There were ethical issues at play in the way interviewees thought about favouritism in leadership episodes. This emerged in the fact that they were concerned with visibility and conduct before engaging in favouritism. Our findings illustrate a bricolage of ethical justifications for favouritism, namely utilitarian, justice, and relational. Such findings suggest the ethical ambiguity that lies at the heart of leadership as a concept and a practice

Business ethics as practice

In this article we develop a conceptualization of business ethics as practice. Starting from the view that the ethics that organizations display in practice will have been forged through an ongoing process of debate and contestation over moral choices, we examine ethics in relation to the ambiguous, unpredictable, and subjective contexts of managerial action. Furthermore, we examine how discursively constituted practice relates to managerial subjectivity and the possibilities of managers being moral agents. The article concludes by discussing how the 'ethics as practice' approach that we expound provides theoretical resources for studying the different ways that ethics manifest themselves in organizations as well as providing a practical application of ethics in organizations that goes beyond moralistic and legalistic approaches. © 2006 British Academy of Management

Eyes wide open: perceived exploitation and its consequences

Drawing on the array of literature on exploitation from several social science disciplines, we propose a new way of seeing employer-employee relationships by introducing the concept of perceived exploitative employee-organization relationships, distinguish it from related concepts, and conduct five studies to develop a scale and test our theoretical model of the effects of such employee perceptions. Contributing to the Employee-Organization Relationships and workplace emotions literatures, perceived exploitation is defined as employees’ perceptions that they have been purposefully taken advantage of in their relationship with the organization, to the benefit of the organization itself. We propose and find that such perceptions are associated with both outward-focused emotions of anger and hostility toward the organization and inward-focused ones of shame and guilt at remaining in an exploitative job. In two studies including construction workers and a time-lagged study of medical residents, we find that the emotions of anger and hostility partially mediate the effects of perceived exploitation on employee engagement, revenge against the organization, organizational commitment, and turnover intentions, whereas the emotions of shame and guilt partially mediate the effects of perceived exploitation on employee burnout, silence, and psychological withdrawal

Comparative losses of quantitative and molecular genetic variation in finite populations of Drosophila melanogaster

Quantitative genetic variation, the main determinant of the ability to evolve, is expected to be lost in small populations, but there are limited data on the effect, and controversy as to whether it is similar to that for near neutral molecular variation. Genetic variation for abdominal and sternopleural bristle numbers and allozyme heterozygosity were estimated in 23 populations of Drosophila melanogaster maintained at effective population sizes of 25, 50, 100, 250 or 500 for 50 generations, as well as in 19 highly inbred populations and the wild outbred base population. Highly significant negative regressions of proportion of initial genetic variation retained on inbreeding due to finite population size were observed for both quantitative characters (b=−0·67±0·14 and −0·58±0·11) and allozyme heterozygosity (b=−0·79±0·10), and the regression coefficients did not differ significantly. Thus, quantitative genetic variation is being lost at a similar rate to molecular genetic variation. However, genetic variation for all traits was lost at rates significantly slower than predicted by neutral theory, most likely due to associative overdominance. Positive, but relatively low correlations were found among the different measures of genetic variation, but their low magnitudes were attributed to large sampling errors, rather than differences in the underlying processes of loss

Islands of water in a sea of dry land: hydrological regime predicts genetic diversity and dispersal in a widespread fish from Australia's arid zone, the golden perch (Macquaria ambigua)

Rivers provide an excellent system to study interactions between patterns of biodiversity structure and ecological processes. In these environments, gene flow is restricted by the spatial hierarchy and temporal variation of connectivity within the drainage network. In the Australian arid zone, this variability is high and rivers often exist as isolated waterholes connected during unpredictable floods. These conditions cause boom/bust cycles in the population dynamics of taxa, but their influence on spatial genetic diversity is largely unknown. We used a landscape genetics approach to assess the effect of hydrological variability on gene flow, spatial population structure and genetic diversity in an Australian freshwater fish, Macquaria ambigua. Our analysis is based on microsatellite data of 590 samples from 26 locations across the species range. Despite temporal isolation of populations, the species showed surprisingly high rates of dispersal, with population genetic structure only evident among major drainage basins. Within drainages, hydrological variability was a strong predictor of genetic diversity, being positively correlated with spring-time flow volume. We propose that increases in flow volume during spring stimulate recruitment booms and dispersal, boosting population size and genetic diversity. Although it is uncertain how the hydrological regime in arid Australia may change under future climate scenarios, management strategies for arid-zone fishes should mitigate barriers to dispersal and alterations to the natural flow regime to maintain connectivity and the species’ evolutionary potential. This study contributes to our understanding of the influence of spatial and temporal heterogeneity on population and landscape processes.15 page(s

Evolution and maintenance of divergent lineages in an endangered freshwater fish, Macquaria australasica

Variable hydrological regimes and habitat availability are factors that affect the distribution of freshwater dependent species and are expected to influence their levels of genetic diversity. Although geologically relatively stable, the south eastern region of Australia has experienced significant changes in hydrological conditions during the Quaternary. This area has also been recently affected by anthropogenic activities, resulting in dramatic population declines of Macquarie Perch (Macquaria australasica). We conducted a range-wide phylogeographic study of this endangered fish to assess the relationship between landscape and freshwater fish evolution in south eastern Australia and infer levels of genetic diversity and population structure. Surprisingly, we detected high genetic diversity, with 46 mtDNA control region haplotypes found across 37 sampling locations. Some lineages were remarkably divergent; one represents a putative undescribed species that probably went extinct during the period of this study. Our reconstruction of population history using a combination of coalescent and phylogenetic methods indicates that the species originated on the coast, east of the Great Dividing Range (GDR), with subsequent colonisation of the Murray-Darling basin, west of the GDR. Nested clade and IM analyses inferred a series of range expansions and fragmentations across the species range consistent with the history of climatic oscillations in south eastern Australia during the Pleistocene. We conclude that the unexpected high levels of diversity and divergence observed in M. australasica may be due to specific habitat requirements, localised recruitment, and Pleistocene climate fluctuations. Under expectations of a drier climate and increased sea levels due to global warming, populations of this and other freshwater species may be expected to experience increased habitat fragmentation and loss of genetic diversity. Conservation management should focus on habitat protection, the maintenance of genetic diversity and taxonomic review.14 page(s