A fish for all seasons: Spatial and temporal variation in patterns of demographic heterogeneity for Retropinna retropinna

<p>Demographic heterogeneity can have big effects on population dynamics, but for most species we have limited understanding of how and why individuals vary. Variation among individuals is of particular importance for stage-structured populations, and/or where species have ‘complex life-cycles’. This is especially relevant in the case of amphidromous fishes that typically spawn in river mouths and estuaries, develop at sea and return to freshwater to finish development. These fish face strong selection pressures as they negotiate challenges around dispersal and development in order to reproduce successfully. Quantifying variation amongst individual fish can improve understanding of their population dynamics and suggest possible drivers of variation. I evaluate patterns and sources of variation in demographic attributes of the New Zealand smelt (Retropinna retropinna). R. retropinna is an amphidromous fish that is endemic to New Zealand. While most populations have a sea-going larval stage, a number of landlocked freshwater populations occur, with the largest landlocked population residing in Lake Taupo. Here R. retropinna are presented with a variety of littoral feeding/spawning habitats and environmental conditions that may vary across distinct regions of the lake. In addition, the protracted spawning period for this species in Lake Taupo (occurring over eight months of the year) provides additional scope for seasonal variation to influence demographic attributes of individuals. I sampled R. retropinna from discrete coastal habitats (beach or river) that were located in the eastern, southern and western regions of the lake. I evaluated patterns of variation in the size-structure, age-structure and morphology of R. retropinna among habitats and/or regions across Lake Taupo. I used otoliths to reconstruct demographic histories (ages, growth rates, hatch dates) of individuals, and used a set of statistical models to infer spatial variation in demographic histories. I found differences in size and age structure between regions, and a temporal effect of hatch date on larval/juvenile growth rates. In addition, I obtained samples of R. retropinna from a sea-going population at the Hutt river mouth (sampled fish were presumed to be migrating upstream after their development period in Wellington Harbour and/or adjacent coastal environments). While Lake Taupo is large, deep, fresh, oligotrophic and strongly stratified for 8-9 months outside of winter, Wellington Harbour is less than a sixth of the area, shallow, saline, eutrophic and never stratified. These greatly differing environmental conditions led me to expect that these systems’ R. retropinna populations would carry significantly different demographic attributes. I compared the hatching phenology, recruitment age, body morphology, and individual growth histories (reconstructed from otoliths) of R. retropinna sampled from Lake Taupo and Wellington Harbour. I explored the relationships between demographic variation and environmental variation (water temperature, chlorophyll a) for the two systems and found that this additional environmental information could account for much of the seasonal variation in daily otolith increment widths of R. retropinna. My results also suggest that while the two sampled populations likely share similar hatching and spawning phenologies, individuals from Lake Taupo tend to grow more slowly, particularly during winter, and end up smaller than sea-going fish sampled near Wellington. I speculate that these differences reflect variation in food supply (zooplankton may be limited in Lake Taupo over winter). Overall, my results demonstrate a high degree of variation in morphological and life-history traits within a single species, potentially driven by an interaction between environmental variation and timing of development. My work contributes to a growing body of literature on demographic heterogeneity, and may help to inform the management of landlocked populations of R. retropinna in Lake Taupo.</p>

A fish for all seasons: Spatial and temporal variation in patterns of demographic heterogeneity for Retropinna retropinna

<p>Demographic heterogeneity can have big effects on population dynamics, but for most species we have limited understanding of how and why individuals vary. Variation among individuals is of particular importance for stage-structured populations, and/or where species have ‘complex life-cycles’. This is especially relevant in the case of amphidromous fishes that typically spawn in river mouths and estuaries, develop at sea and return to freshwater to finish development. These fish face strong selection pressures as they negotiate challenges around dispersal and development in order to reproduce successfully. Quantifying variation amongst individual fish can improve understanding of their population dynamics and suggest possible drivers of variation. I evaluate patterns and sources of variation in demographic attributes of the New Zealand smelt (Retropinna retropinna). R. retropinna is an amphidromous fish that is endemic to New Zealand. While most populations have a sea-going larval stage, a number of landlocked freshwater populations occur, with the largest landlocked population residing in Lake Taupo. Here R. retropinna are presented with a variety of littoral feeding/spawning habitats and environmental conditions that may vary across distinct regions of the lake. In addition, the protracted spawning period for this species in Lake Taupo (occurring over eight months of the year) provides additional scope for seasonal variation to influence demographic attributes of individuals. I sampled R. retropinna from discrete coastal habitats (beach or river) that were located in the eastern, southern and western regions of the lake. I evaluated patterns of variation in the size-structure, age-structure and morphology of R. retropinna among habitats and/or regions across Lake Taupo. I used otoliths to reconstruct demographic histories (ages, growth rates, hatch dates) of individuals, and used a set of statistical models to infer spatial variation in demographic histories. I found differences in size and age structure between regions, and a temporal effect of hatch date on larval/juvenile growth rates. In addition, I obtained samples of R. retropinna from a sea-going population at the Hutt river mouth (sampled fish were presumed to be migrating upstream after their development period in Wellington Harbour and/or adjacent coastal environments). While Lake Taupo is large, deep, fresh, oligotrophic and strongly stratified for 8-9 months outside of winter, Wellington Harbour is less than a sixth of the area, shallow, saline, eutrophic and never stratified. These greatly differing environmental conditions led me to expect that these systems’ R. retropinna populations would carry significantly different demographic attributes. I compared the hatching phenology, recruitment age, body morphology, and individual growth histories (reconstructed from otoliths) of R. retropinna sampled from Lake Taupo and Wellington Harbour. I explored the relationships between demographic variation and environmental variation (water temperature, chlorophyll a) for the two systems and found that this additional environmental information could account for much of the seasonal variation in daily otolith increment widths of R. retropinna. My results also suggest that while the two sampled populations likely share similar hatching and spawning phenologies, individuals from Lake Taupo tend to grow more slowly, particularly during winter, and end up smaller than sea-going fish sampled near Wellington. I speculate that these differences reflect variation in food supply (zooplankton may be limited in Lake Taupo over winter). Overall, my results demonstrate a high degree of variation in morphological and life-history traits within a single species, potentially driven by an interaction between environmental variation and timing of development. My work contributes to a growing body of literature on demographic heterogeneity, and may help to inform the management of landlocked populations of R. retropinna in Lake Taupo.</p>

U.S. national, regional, and state-specific socioeconomic factors correlate with child and adolescent ADHD diagnoses pre-COVID-19 pandemic

Attention-deficit/hyperactivity disorder (ADHD), the most diagnosed emerging neurodevelopmental disorder in children, is a growing health crisis in the United States. Due to the potential increase in ADHD severity during and post the COVID-19 pandemic, we analyzed recent national and two state-specific ADHD data distribution among U.S. children and adolescents by investigating a broad range of socioeconomic status (SES) factors. Child and adolescent ADHD diagnosis and treatment data were parent-reported via National Survey of Children’s Health (NSCH). The nationwide childhood prevalence of ADHD is 8.7%, and 62.1% of diagnosed children are taking medication. Louisiana (15.7%) has the highest percentage of children diagnosed with ADHD and California (5.6%) has the lowest, followed by Nevada (5.9%). Multiple correspondence analysis (MCA, n = 51,939) examining 30 factors highlights four areas of interest at the national and state level: race/ethnicity, financial status, family structure, and neighborhood characteristics. Positive correlations between ADHD diagnosis and unsafe school, unsafe neighborhood, and economic hardship are evident nationally and statewide, while the association between a lack of ADHD diagnosis and higher urban neighborhood amenities are evident nationally, but not in two opposing outlier states—Louisiana or Nevada. National and state-specific hierarchical analyses demonstrate significant correlations between the various SES factors and ADHD outcomes. Since the national analysis does not account for the demographic heterogeneity within regions or individual states, the U.S. should rely on comprehensive, county-specific, near real-time data reporting to effectively model and mitigate the ADHD epidemic and similar national health crises.

Assessing Local and National Government Interaction in LED: A Policy Evaluation of South Africa’s Metros

The article examined the adoption of the 2018-2028 National Framework for Local Economic Development (NFLED 2018-2028) in South Africa eight metropolitan municipalities. The article employs a qualitative research approach whereby a document analysis of municipality strategic reports reveals that there is low adoption of the National Framework for Local Economic Development in South African metros. The findings confirm that whilst metropolitan municipalities cannot be expected to share the exact policy adoption considerations due to their political, administrative, economic and demographic heterogeneity, it is suggested that there should be a balanced level of policy standardisation when it comes to LED and other municipal kep performance areas (KPAs). The article concludes that South Africa’s metropolitan municipalities had not adopted most of the five enabling pillars of the National Framework for LED 2018-2028 as part of the key performance areas (KPAs). This points to the discord between national LED policies and local level LED planning. While there is a need for LED planning decentralisation to meet local needs in metros, general alignment with national policies could assist in unlocking intellectual and financial resources that municipalities lack. Received: 23 September 2021 / Accepted: 25 October 2021 / Published: 5 November 2021

Longitudinal survey data for diversifying temporal dynamics in flood risk modelling

Scholars have unravelled the complexities and underlying uncertainties in coupled human and water systems in various fields and disciplines. These complexities, however, are not always reflected in the way in which the dynamics of human–water systems are modelled. One reason is the lack of social data time series, which may be provided by longitudinal surveys. Here, we show the value of collecting longitudinal survey data to enrich sociohydrological modelling of flood risk. To illustrate, we compare and contrast two different approaches (repeated cross-sectional and panel) for collecting longitudinal data and explore changes in flood risk awareness and preparedness in a municipality hit by a flash flood in 2018. We found that risk awareness has not changed significantly in the timeframe under study (1 year). Perceived preparedness increased only among those respondents who suffered low damage during the flood event. We also found gender differences across both approaches for most of the variables explored. Lastly, we argue that results that are consistent across the two approaches can be used for the parametrisation of sociohydrological models. We posit that there is a need to enhance the representation of socio-demographic heterogeneity in modelling human–water systems in order to better support risk management.

Parenting Contributions to Latinx Children’s Development in the Early Years

Despite comparatively high levels of poverty, Latinx parents, on average, provide their children with early home experiences that promote development at rates that at least equal that of other demographic groups. From a strength-based perspective, we describe the demographic heterogeneity among Latinx children during early childhood (zero to eight years), given that these years are critical for later development. We then discuss the individual- and family-level factors that promote positive outcomes in Latinx children despite the presence of economic and social stressors. We synthesize these findings to generate policy recommendations that support Latinx families and children by addressing their specific needs and building on the strengths they already possess.

Geographic and demographic heterogeneity of SARS-CoV-2 diagnostic testing in Illinois, USA, March to December 2020

Background Availability of SARS-CoV-2 testing in the United States (U.S.) has fluctuated through the course of the COVID-19 pandemic, including in the U.S. state of Illinois. Despite substantial ramp-up in test volume, access to SARS-CoV-2 testing remains limited, heterogeneous, and insufficient to control spread. Methods We compared SARS-CoV-2 testing rates across geographic regions, over time, and by demographic characteristics (i.e., age and racial/ethnic groups) in Illinois during March through December 2020. We compared age-matched case fatality ratios and infection fatality ratios through time to estimate the fraction of SARS-CoV-2 infections that have been detected through diagnostic testing. Results By the end of 2020, initial geographic differences in testing rates had closed substantially. Case fatality ratios were higher in non-Hispanic Black and Hispanic/Latino populations in Illinois relative to non-Hispanic White populations, suggesting that tests were insufficient to accurately capture the true burden of COVID-19 disease in the minority populations during the initial epidemic wave. While testing disparities decreased during 2020, Hispanic/Latino populations consistently remained the least tested at 1.87 tests per 1000 population per day compared with 2.58 and 2.87 for non-Hispanic Black and non-Hispanic White populations, respectively, at the end of 2020. Despite a large expansion in testing since the beginning of the first wave of the epidemic, we estimated that over half (50–80%) of all SARS-CoV-2 infections were not detected by diagnostic testing and continued to evade surveillance. Conclusions Systematic methods for identifying relatively under-tested geographic regions and demographic groups may enable policymakers to regularly monitor and evaluate the shifting landscape of diagnostic testing, allowing officials to prioritize allocation of testing resources to reduce disparities in COVID-19 burden and eventually reduce SARS-CoV-2 transmission.

Canadian ethnic media and social capital development : Examining the relationship between broadcasting policy, multicultural programming and sociocultural integration and cohesion in Canada

Using Canada as a case for analysis, this research investigates the potential for ethnic media, which are mandated to deliver content directed to "racially and culturally distinct" (CRTC, 1999) groups that are not English, French or Aboriginal, to act as an integrative tool for allophone communities, and to stimulate intercultural exchanges amongst all Canadians that can lead to the development of social capital. Given Canada's extraordinary demographic heterogeneity, the mechanisms in place to encourage the development of networks between and among ethnic communities are increasingly important for supporting social solidarity in the broader population (Putnam, 2006). Canada's Broadcasting Act, §3(1)(d)(iii) (1991) and related policies which the Act initiates, including the Ethnic Broadcasting Policy, provide a policy framework for the creation and distribution of culturally and linguistically diverse content" to Canadian audiences, demonstrating official support for the potential social benefits associated with the national availability of ethnic media. By developing culturally and linguistically diverse content aligned with the demographic realities of the Canadian population within a supportive policy environment, ethnic media can provide, an important platform for sharing information and ideas across vast geographic or sociocultural divides, as well as a venue for fostering community building, civic involvement and an active dialogue amongst Canadians of all backgrounds. This research seeks to explore and develop theoretical linkages between the existing policy framework governing ethnic broadcasting in Canada, the broadcasting sector's methods of compliance with existing regulation, and the development of social capital.

Canadian ethnic media and social capital development : Examining the relationship between broadcasting policy, multicultural programming and sociocultural integration and cohesion in Canada

Using Canada as a case for analysis, this research investigates the potential for ethnic media, which are mandated to deliver content directed to "racially and culturally distinct" (CRTC, 1999) groups that are not English, French or Aboriginal, to act as an integrative tool for allophone communities, and to stimulate intercultural exchanges amongst all Canadians that can lead to the development of social capital. Given Canada's extraordinary demographic heterogeneity, the mechanisms in place to encourage the development of networks between and among ethnic communities are increasingly important for supporting social solidarity in the broader population (Putnam, 2006). Canada's Broadcasting Act, §3(1)(d)(iii) (1991) and related policies which the Act initiates, including the Ethnic Broadcasting Policy, provide a policy framework for the creation and distribution of culturally and linguistically diverse content" to Canadian audiences, demonstrating official support for the potential social benefits associated with the national availability of ethnic media. By developing culturally and linguistically diverse content aligned with the demographic realities of the Canadian population within a supportive policy environment, ethnic media can provide, an important platform for sharing information and ideas across vast geographic or sociocultural divides, as well as a venue for fostering community building, civic involvement and an active dialogue amongst Canadians of all backgrounds. This research seeks to explore and develop theoretical linkages between the existing policy framework governing ethnic broadcasting in Canada, the broadcasting sector's methods of compliance with existing regulation, and the development of social capital.

Towards an Even More Spatially Diversified City? New Metropolitan Population Trends in the Post-Economic Crisis Period

After the deep economic crisis that began in 2008, in 2014, Spain started to show signs of recovery, entering the so-called “post-crisis” period. Though it has not yet reached the entire population, economic improvement has had a positive impact on the real estate market, economic activity, and employment. Residential mobility has also increased, but flows have become more unstable and complex. The direction of these flows, the reasons for moving, and the ages and socioeconomic categories of migrants have diversified. These complex “new mobility” patterns are reconfiguring the spatial distribution of the population in Spanish urban areas. On the basis of Continuous Register (Padrón Continuo) microdata, this paper primarily aims to study population changes in the 69 Spanish functional urban areas (FUAs) defined by the National Institute of Statistics (INE)/Eurostat, focusing on their population growth or decline in their centers and peripheries during the crisis (2011–2015) and post-crisis (2015–2019) phases. Then, the paper analyzes the five major Spanish metropolises (Madrid, Barcelona, Valencia, Seville, and Bilbao) in greater depth. The findings confirm the hypothesis that, during the post-crisis period, the population growth of cores and rings and thus the spatial distribution of urban inhabitants have been changing, resulting in the growing demographic heterogeneity of Spanish urban areas that are diversifying both internally and compared to each other.