Greater Population Size Research Articles

Does the population size of a city matter to its older adults' self-rated health? Results of China data analysis.

Clarifying the association between city population size and older adults' health is vital in understanding the health disparity across different cities in China. Using a nationally representative dataset, this study employed Multilevel Mixed-effects Probit regression models and Sorting Analysis to elucidate this association, taking into account the sorting decisions made by older adults. The main results of the study include: (1) The association between city population size and the self-rated health of older adults shifts from a positive linear to an inverted U-shaped relationship once individual socioeconomic status is controlled for; the socioeconomic development of cities, intertwined with the growth of their populations, plays a pivotal role in yielding health benefits. (2) There is a sorting effect in older adults' residential decisions; compared to cities with over 5 million residents, unobserved factors result in smaller cities hosting more less-healthy older adults, which may cause overestimation of health benefits in cities with greater population size. (3) The evolving socioeconomic and human-made environment resulting from urban population growth introduces health risks for migratory older adults but yields benefits for those with local resident status who are male, aged over 70, and have lower living standards and socioeconomic status. And (4) The sorting effects are more pronounced among older adults with greater resources supporting their mobility or those without permanent local resident status. Thus, policymakers should adapt planning and development strategies to consider the intricate relationship between city population size and the health of older adults.

Recombination as an enforcement mechanism of prosocial behavior in cooperating bacteria

Prosocial behavior is ubiquitous in nature despite the relative fitness costs carried by cooperative individuals. However, the stability of cooperation in populations is fragile and often maintained through enforcement. We propose that homologous recombination provides such a mechanism in bacteria. Using an agent-based model of recombination in bacteria playing a public goods game, we demonstrate how changes in recombination rates affect the proportion of cooperating cells. In our model, recombination converts cells to a different strategy, either freeloading (cheaters) or cooperation, based on the strategies of neighboring cells and recombination rate. Increasing the recombination rate expands the parameter space in which cooperators outcompete freeloaders. However, increasing the recombination rate alone is neither sufficient nor necessary. Intermediate benefits of cooperation, lower population viscosity, and greater population size can promote the evolution of cooperation from within populations of cheaters. Our findings demonstrate how recombination influences the persistence of cooperative behavior in bacteria.

Spatial Pattern and Ecological Process Difference Analyses of the Boundary Habitats of a Treeline Patch: A Case Study from the Li Mountain, North China

Treeline patches are among Earth’s most sensitive and are important model ecosystems for assessing climate change trends. To explore ecological factors that limit the species’ survival in treelines, the treeline patch of Li Mountain National Nature Reserve was selected as the research site. Pinus armandii (P. armandii), Betula albo-sinensis (B. albo-sinensis), and Betula utilis (B. utilis) were selected as research species based on their dominance. Two 50 m × 50 m plots were established separately from the upper and lower limits of the highest treeline patch for point pattern analysis. Five 10 m × 10 m quadrats per plot were sampled to investigate the flora and environmental factors. The results showed that: (1) Slope and community composition at tree layer in quadrates had significant differences between upper and lower limits. Pinus armandii had a greater population size at the upper limit. Seedling recruitment restricted population development for B. albo-sinensis at the lower limit and B. utilis at the upper limit and less regeneration of B. albo-sinensis at the upper limit. (2) More aggregation scales occurred at the upper limit, and P. armandii had more aggregation scales than the other two species at 0–25 m. The heterogeneity caused by density distribution affected P. armandii pattern at the upper limit, and heterogeneity of seed dispersal could explain species patterns in both limits. Distinctness of size difference may have an influence on inter-specific species correlations.

Flood-Related Federally Declared Disaster Events and Community Functioning (COPEWELL)

Objective: Understanding long-term disaster effects is key to building theories of recovery and informing policymaking. Findings regarding long-term recovery are inconsistent, with some scholars finding that disasters have little long-term impact, and others asserting otherwise. To assist in resolving this discord, we apply a conceptual framework and computational model of community resilience (“COPEWELL”) that places community functioning (CF) at the center of evaluating the effects of disaster over time. Using flooding as a disaster type, we hypothesize a change in baseline CF trend when a flood-related federally declared disaster event occurs. Methods: We used county-level flood-related federally declared disaster events (2010–2014) and selected population demographics to study their effects on annual CF trends among United States counties (N = 3141). Results: In multivariate analysis of baseline CF, we found a significant negative relationship of prior five-year flood status, federal regions relative to the Northeast (Region I), lower total earnings, and greater population size. Annual CF trend was 0.09% (95%CI: 0.01%–0.16%). In multivariate analysis, significant predictors included baseline CF (β = −0.0178, −0.0047–−0.0309), any concurrent flood-related federally declared disaster events (−0.0024, −0.0040–−0.0008), ten-year prior flood events (−0.0017, −0.0034–−0.0000) and concurrent population change (−0.0186, −0.0338–−0.0035). Conclusions: Recent floods depress baseline CF, while concurrent and ten-year-ago floods depress trend in CF. Resilience may potentially be modified by raising baseline CF and maintaining population over time.

Identifying vaccination deserts: The availability and distribution of pharmacists with authorization to administer injections in Ontario

Introduction:Pharmacist-administered immunizations have been associated with improved vaccination rates; however, little is known about whether areas with little to no access to this service (“vaccination deserts”) exist. The objective of this work is to determine the geographic availability of pharmacists with authorization to administer injections in the province of Ontario.Methods:Ontario College of Pharmacists registry data were used to identify patient care–providing pharmacists in community pharmacies and their ability to administer injections. Their number of hours worked was converted into full-time equivalents (FTEs), assuming 40 hours per week represents 1 FTE. Practice site(s) were mapped by postal code and presented by Public Health Unit (PHU) area. Communities within PHUs were further categorized as urban or rural and northern or southern, with ratios of FTEs per 1000 population calculated for both injection-trained and non-injection-trained pharmacists.Results:In total, 74.6% of Ontario’s practising community pharmacists are authorized to provide injections. Northern PHUs had slightly better access to pharmacist injectors (0.61 FTEs/1000 overall vs 0.56/1000 in the south), while rural communities had lower availability (0.41 FTEs/1000) than urban communities (0.58 FTEs/1000). PHUs with greater population size and density had greater availability of pharmacist immunizers, while PHUs with greater land area were more likely to not have any immunizing pharmacists present (p < 0.001 for all).Discussion:As pharmacists increasingly become preferred vaccination providers, awareness of disparities related to access to pharmacy-based immunizations and collaboration with public health and primary care providers to address them (e.g., through mobile vaccination clinics) will be required to ensure equitable access. Can Pharm J (Ott) 2022;155:xx-xx.

Inferring the reproduction number using the renewal equation in heterogeneous epidemics.

Real-time estimation of the reproduction number has become the focus of modelling groups around the world as the SARS-CoV-2 pandemic unfolds. One of the most widely adopted means of inference of the reproduction number is via the renewal equation, which uses the incidence of infection and the generation time distribution. In this paper, we derive a multi-type equivalent to the renewal equation to estimate a reproduction number which accounts for heterogeneity in transmissibility including through asymptomatic transmission, symptomatic isolation and vaccination. We demonstrate how use of the renewal equation that misses these heterogeneities can result in biased estimates of the reproduction number. While the bias is small with symptomatic isolation, it can be much larger with asymptomatic transmission or transmission from vaccinated individuals if these groups exhibit substantially different generation time distributions to unvaccinated symptomatic transmitters, whose generation time distribution is often well defined. The bias in estimate becomes larger with greater population size or transmissibility of the poorly characterized group. We apply our methodology to Ebola in West Africa in 2014 and the SARS-CoV-2 in the UK in 2020–2021.

Two decades of e-government diffusion among local governments in the United States

This study is the first to evaluate e-government diffusion among local governments in the United States over time. The diffusion rates of various types of e-government services are measured and analyzed over two decades. E-government surveys conducted by the International City/County Management Association (ICMA) from 2000 to 2011 provide an early trendline of e-government services offered, and an original two-wave panel survey was conducted in 2014 and 2019 collecting data, which extends this timeline and offers new ways to measure adoption in this later period. The panel survey includes the same 83 cities randomly selected from all cities with populations over 50,000, representing over 10% of medium and large size cities in the U.S.The findings of this study provide a clear picture that cities across the nation have increasingly adopted a wide set of e-gov services, with some reaching near complete diffusion. A total of 45 different e-government services are evaluated, with similar e-government services organized together into informational, interactive, multimedia, financial, and social media scaled variables for further analysis. Adoption and diffusion of e-government services have been neither steady nor uniform. However, from 2014 to 2019 the trend was clear: more cities offered more e-government services more consistently.The findings also offer insights into the characteristics of cities that have adopted e-government innovations earlier than others. Both greater population size and percent of residents with broadband access contribute in a statistically significant way to the number of e-gov services adopted, while other expected independent variables like economic measures of wealth do not. These findings contribute to a broader conversation about how the diffusion of e-government service adoption has changed over time and the extent to which that has affected the relationship between residents and their local governments throughout the first two decades of the 21st Century.

Prevalence of Municipal-Level Policies Dedicated to Transportation That Consider Food Access.

IntroductionLocal governments can address access to healthy food and transportation through policy and planning. This study is the first to examine municipal-level transportation supports for food access.MethodsWe used a nationally representative sample of US municipalities with 1,000 or more persons from the 2014 National Survey of Community-Based Policy and Environmental Supports for Healthy Eating and Active Living (N = 2,029) to assess 3 outcomes: public transit availability, consideration of food access in transportation planning, and presence of demand-responsive transportation (DRT). We used χ2 tests to compare prevalences by municipal characteristics including population size, rurality, census region, median educational attainment, poverty prevalence, racial and ethnic population distribution, and low-income low-access to food (LILA) status.ResultsAmong municipalities, 33.7% reported no public transit and 14.8% reported having DRT. Both public transit and DRT differed by population size (both P < .001) and census region (both P < .001) and were least commonly reported among municipalities with populations less than 2,500 (46.9% without public transit; 6.6% with DRT) and in the South (40.0% without public transit; 11.1% with DRT). Of those with public transit, 33.8% considered food access in transportation planning; this was more common with greater population size (55.9% among municipalities of ≥50,000 persons vs 16.8% among municipalities of <2,500 persons; P < .001), in the West (43.1% vs 26.8% in the Northeast, 33.7% in the Midwest, 32.2% in the South; P = .003), and municipalities with 20% or more of the population living below federal poverty guidelines (37.4% vs 32.2% among municipalities with less than 20% living in poverty; P = .07).ConclusionResults suggest that opportunities exist to improve food access through transportation, especially in smaller and Southern communities, which may improve diet quality and reduce chronic disease.

Testosterone Replacement Therapy in Hypogonadal Men and Myocardial Infarction Risk: Systematic Review & Meta-Analysis.

Testosterone replacement therapy (TRT) has become increasingly popular over the years and there has been an increasing debate on whether testosterone replacement should be offered to older men due to its association with cardiovascular events. In this study, we evaluated the risk of myocardial infarction (MI) associated with TRT in hypogonadal men through a meta-analysis. We carried out the analysis by following the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) guidelines and conducted a literature search utilizing the following databases: Google Scholar, PubMed, Science Direct, Cochrane Library trials, and ClinicalTrials.gov. The search strategy resulted in a total of 782 articles, after applying our inclusion and exclusion criteria. Six observational studies and two randomized controlled trials (RCTs) were included for the analysis. A total of 55,806 hypogonadal men with baseline testosterone levels <300ng/mL were included in the analysis. The intervention group received testosterone in various routes including transdermal patches, gels, mouth patches, testosterone injections, and deposits. The incidence of MI was taken to be the primary measure outcomes. The pooled data from eight studies showed MI incidence in 249 out of 11,720 (2.1%) in the TRT group and 1420 out of 33,086 (4.3%) in the control group. The pooled OD showed no statistically significant association of TRT and MI compared to the control group (OR = 0.76, 95% CI 0.36-1.31; p=0.48). The model revealed high heterogeneity with I2 =79%. With sensitivity analysis and, excluding two studies out of the eight, the pooled data was able to achieve low heterogeneity with I2 = 0%. The newly pooled data from six studies showed MI incidence in 226 out of 10,137 (2.2%) in the TRT group and 969 out of 36,304 (2.7%) in the control group. The pooled OD shows no statistical significance in the association between TRT treatment and MI compared to the control group. (OR =0.87, 95% CI 0.75-1.01; P =0.08). It appears that TRT does not increase the risk of MI as compared to the non-intervention group. Further RCTs with greater population size are needed that could produce more solid results, allowing more definitive conclusions to be made on this topic.

Human centered development of Russian megacities: Opportunities and limitations

Currently, the role of the big cities in the development of economy and society, the organization of high-quality urban space for people are widely discussed. However, there are still many unresolved urban issues with the crucial one being the need for the city-person interaction. Better interaction, diversity in satisfying the population’s needs, feedback from an active citizen who influences the development of the city are the attributes of modern metropolis that competes for any person. City’s advantages result in a greater population size and better quality of their life. Otherwise, the city shows the degradation signs and population decline. The purpose of the study is to justify the need for a multi-criteria assessment of living conditions in the Russian megalopolises under the citizens’ needs and the improvement of modern urban space. This assessment could guide the managerial decisions in defining the strategic priorities in city development. The following methodological tools were used: experts’ assessments of urban environment quality, demographic analysis of urban population movement; positioning of Russian megacities by criteria ‘urban environment quality’ and ‘population’s cost of living’, their grouping by the qualitative characteristics of urban environment; content analysis of the strategic documents for the development of the largest megacities. The novelty of the study is a new interpretation of the concept of ‘place’ in terms of the urban area. It is defined in a broader sense rather than a particular localization with the borders. It is an urban environment with a set of different opportunities to meet citizens’ growing needs. The study arrives at the approaches to a multi-criteria assessment of the living conditions in million cities under the citizens’ needs. To do this, the authors applied the methods of the Ministry of Construction, Housing and Utilities in the Russian Federation and analyzed the conditions and dynamics of the urban environment, studied the demographic processes, and evaluated the megalopolis attractiveness under the income and cost of living ratio. This revealed the challenges of the cities which could be theoretically solved in the strategic documents of megalopolis development, while the development of efficient mechanisms could help in the practical implementation of the solutions (municipal programs and projects). The article offers to analyze and constantly update the strategic documents of the million cities with regard to the public opinion and the needs of city dwellers in high-quality urban space. The authors worded the need to re-define the urban space which used to be interpreted as a place for living and the human role in its development. The results of the study could be of interest to public authorities and local governments that strategically manage the million cities. Further research is seen to be connected with the development of a comprehensive integral multi-criteria assessment for the current condition and dynamics in the urban space quality to define the megalopolis competitiveness in terms of their interest for the citizens.

A SIRD epidemic model with community structure.

The study of epidemics spreading with community structure has become a hot topic. The classic SIR epidemic model does not distinguish between dead and recovered individuals. It is inappropriate to classify dead individuals as recovered individuals because the real-world epidemic spread processes show different recovery rates and death rates in different communities. In the present work, a SIRD epidemic model with different recovery rates is proposed. We pay more attention to the changes in the number of dead individuals. The basic reproductive number is obtained. The stationary solutions of a disease-free state and an endemic state are given. We show that quarantining communities can decrease the basic reproductive number, and the total number of dead individuals decreases in a disease-free steady state with an increase in the number of quarantined communities. The most effective quarantining strategy is to preferentially quarantine some communities/cities with a greater population size and a fraction of initially infected individuals. Furthermore, we show that the population flows from a low recovery rate and high population density community/city/country to some high recovery rate and low population density communities/cities/countries, which helps to reduce the total number of dead individuals and prevent the prevalence of epidemics. The numerical simulations on the real-world network and the synthetic network further support our conclusions.

Policies for Autonomy: How American Cities Envision Regulating Automated Vehicles

Local governments play an important role in structuring urban transportation through street design, zoning, and shared jurisdiction over ride-hailing, transit, and road pricing. While cities can harness these powers to steer planning outcomes, there is little research about what local officials think about regulatory changes related to autonomous vehicles (AV). We compile key AV-related policies recommended by scholars but rarely implemented, and conduct a survey of municipal officials throughout the United States, exploring their personal support and perceptions of bureaucratic capacity, legal limits, and political backing for each policy. This paper finds broad personal support for regulations related to right-of-way, equity, and land use, such as for increasing pedestrian space, expanding access for low-income people, and reducing sprawl. However, officials emphasized uncertain bureaucratic and legal capacity for city intervention outside of these areas, reaffirming limited local power in the federal system. Only a minority expected political support for any policy. Greater population size and more liberal resident political ideologies are strongly associated with personal and political support for many policies. Local population growth is correlated with greater capacity to undertake policies. This work contributes to the growing literature on transportation governance in the context of technological uncertainty.

Characterising variability and predictors of infant mortality in urban settings: findings from 286 Latin American cities

BackgroundUrbanisation in Latin America (LA) is heterogeneous and could have varying implications for infant mortality (IM). Identifying city factors related to IM can help design policies that promote infant health...

Predicting the Future Course of Opioid Overdose Mortality: An Example From Two US States.

The rapid growth of opioid abuse and the related mortality across the United States has spurred the development of predictive models for the allocation of public health resources. These models should characterize heterogeneous growth across states using a drug epidemic framework that enables assessments of epidemic onset, rates of growth, and limited capacities for epidemic growth. We used opioid overdose mortality data for 146 North and South Carolina counties from 2001 through 2014 to compare the retrodictive and predictive performance of a logistic growth model that parameterizes onsets, growth, and carrying capacity within a traditional Bayesian Poisson space-time model. In fitting the models to past data, the performance of the logistic growth model was superior to the standard Bayesian Poisson space-time model (deviance information criterion: 8,088 vs. 8,256), with reduced spatial and independent errors. Predictively, the logistic model more accurately estimated fatality rates 1, 2, and 3 years in the future (root mean squared error medians were lower for 95.7% of counties from 2012 to 2014). Capacity limits were higher in counties with greater population size, percent population age 45-64, and percent white population. Epidemic onset was associated with greater same-year and past-year incidence of overdose hospitalizations. Growth in annual rates of opioid fatalities was capacity limited, heterogeneous across counties, and spatially correlated, requiring spatial epidemic models for the accurate and reliable prediction of future outcomes related to opioid abuse. Indicators of risk are identifiable and can be used to predict future mortality outcomes.

Take one step backward to move forward: Assessment of genetic diversity and population structure of captive Asian woolly-necked storks (Ciconia episcopus).

The fragmentation of habitats and hunting have impacted the Asian woolly-necked stork (Ciconia episcopus), leading to a serious risk of extinction in Thailand. Programs of active captive breeding, together with careful genetic monitoring, can play an important role in facilitating the creation of source populations with genetic variability to aid the recovery of endangered species. Here, the genetic diversity and population structure of 86 Asian woolly-necked storks from three captive breeding programs [Khao Kheow Open Zoo (KKOZ) comprising 68 individuals, Nakhon Ratchasima Zoo (NRZ) comprising 16 individuals, and Dusit Zoo (DSZ) comprising 2 individuals] were analyzed using 13 microsatellite loci, to aid effective conservation management. Inbreeding and an extremely low effective population size (Ne) were found in the KKOZ population, suggesting that deleterious genetic issues had resulted from multiple generations held in captivity. By contrast, a recent demographic bottleneck was observed in the population at NRZ, where the ratio of Ne to abundance (N) was greater than 1. Clustering analysis also showed that one subdivision of the KKOZ population shared allelic variability with the NRZ population. This suggests that genetic drift, with a possible recent and mixed origin, occurred in the initial NRZ population, indicating historical transfer between captivities. These captive stork populations require improved genetic variability and a greater population size, which could be achieved by choosing low-related individuals for future transfers to increase the adaptive potential of reintroduced populations. Forward-in-time simulations such as those described herein constitute the first step in establishing an appropriate source population using a scientifically managed perspective for an in situ and ex situ conservation program in Thailand.

Investigating Factors of Twitter Use among Municipal Governments

ABSTRACT This study investigates predictors of Twitter adoption and use by municipalities for citizen communication, considering both the level of municipal Twitter presence and the level of Twitter activity. Possible predictors included municipal characteristics as well as citizenry characteristics. Participants included 100 Pennsylvania municipalities drawn from a disproportionate stratified sample, evenly split between municipalities with and without a Twitter presence. No significant correlation was found between the level of municipal Twitter presence and active use of Twitter. Regression results suggest that the likelihood of adopting a Twitter account increases with greater population size and a younger population, though only population size significantly predicts the number of Twitter accounts. Regression results also suggest that a greater population size, lesser median citizen income, and a higher number of county-level Twitter accounts influence the level of Twitter activity among these municipalities.

Impact of fermentation temperature on required heat dissipation, growth and viability of yeast, on sensory characteristics and on the formation of volatiles in Riesling

Background and Aims Temperature control during fermentation significantly impacts the energy demand of wineries. We determined the heat required to be dissipated from wine tanks under three different temperature programs (14, 16–11–17 and 19°C) during 1200 L Riesling fermentations and investigated the influence of temperature on yeast growth and viability, the formation of yeast derived volatiles and wine sensory properties. Methods and Results Heat dissipated by the coolant was determined using heat meters. At 19°C, ~70% less heat had to be dissipated compared to that at 14°C, whereas ~30% less heat had to be dissipated for the 16–11–17°C temperature program. The duration of fermentation was 15, 13 and 9 days for the 14, 16–11–17 and 19°C programs, respectively. Characteristic profiles of heat dissipated per day and reduction in specific gravity were observed. The formation of most esters was more pronounced in the second half of fermentation at higher temperature. Hexyl acetate, however, was formed early and no temperature influence was observed. The final concentration of ethyl decanoate, ethyl octanoate and ethyl hexanoate was greater for fermentations at 19°C, while that of ethyl butanoate was highest at 14°C. No difference was found in the final concentration of acetate esters or acetic acid. Acetaldehyde concentration was 35% lower for fermentations at 19°C, compared with those at 14°C. Descriptive analysis, at 5 and 11 months after bottling, revealed no significant difference in wine sensory profiles. Flow cytometry showed faster yeast growth, greater population size and rapid viability decline at the higher fermentation temperature. Conclusions Energy savings can be achieved by reducing the required dissipated heat through temperature management of fermentations, without compromising wine composition. Ambient temperature should be considered when deciding on temperature management and related saving potentials. Significance of the Study Potential energy savings were demonstrated that may facilitate innovation in fermentation cooling systems.

Better colony performance, not natural enemy release, explains numerical dominance of the exotic Polistes dominula wasp over a native congener in South Africa

The European paper wasp Polistes dominula has invaded many parts of the globe and often displaces similar native species. Factors contributing to this remain unclear but may include longer seasonal activity period, natural enemy release, greater colony productivity and smaller body size. Since its discovery in South Africa in 2008, the local abundance of P. dominula has increased greatly. In invaded habitats, it is now much more common than the native P. marginalis. Here we determine some of the factors that enable dominance of P. dominula over the native congener during early stages of the invasion process. The activity of both species was monitored in four habitat types (urban, rural, fringe and natural) to determine differences in abundance, seasonal activity period, and habitat preference. Nests and individuals of both species were collected and compared for colony productivity (nest size), parasitism levels, and size of individuals. Both species preferred anthropogenically altered habitats, with P. dominula significantly more abundant than P. marginalis. Contrary to expectation, the exotic species suffered significantly higher parasitism than the native species. However, P. dominula had a substantially longer activity period and greater colony productivity than P. marginalis. P. dominula is therefore able to reach much greater population size than P. marginalis despite higher parasitoid pressure and similar individual size due to better colony performance. This has implications for future biological control initiatives.

Weather conditions and variation in timing of spring and fall migrations of migratory caribou

Species that make long-distance migrations face changes in the phenology of natural processes linked to global climate changes. Mismatch between the onset of resources and arrival on breeding grounds or changes in the conditions faced during migration such as early snowmelt in northern environments could have severe impacts on migrant populations. We investigated the impact of local weather and broad-scale climate and of the availability of forage resources on timing of spring and fall migrations of migratory caribou ( Rangifer tarandus ) from the Riviere-George and Riviere-aux-Feuilles herds in northern Quebec and Labrador, Canada. We tested the effect of local weather using data provided by the Canadian Regional Climate Model, a large-scale climate index, snow and ice cover, and the Normalized Difference Vegetation Index on departure and arrival dates of 377 spring migrations and 499 fall migrations of female caribou. Since 2000, except for the spring arrival, migrations tended to occur earlier. Spring arrival was delayed when caribou encountered mild temperatures and abundant precipitation during migration, as early snowmelt may increase cost of movements. At greater population sizes, caribou seemed to limit the time spent on summer range by arriving later and departing earlier, possibly to limit competition for summer forage. During fall, caribou adjusted their migration to conditions en route because they arrived earlier if November was snowy and mild, possibly to limit the costs of moving through deep snow. Like numerous migrant species, most caribou herds are declining, and it is crucial to assess which environmental factors affect migrant populations. Our study contributes to the understanding of the impact of local weather conditions and climate change on migratory land mammals.

A cloud computing based many objective type-2 fuzzy logic system for mobile field workforce area optimization

Large scale optimization problems in the real world are often very complex and require multiple objectives to be satisfied. This applies to industries that employ a large mobile field workforce. Sub-optimal allocation of tasks to engineers in this workforce can lead to poor customer service, higher travel costs and higher CO $$_{2}$$ emissions. One solution is to create optimal working areas, which are geographical regions containing many task locations, where the engineers can work. Finding the optimal design of these working areas as well as assigning the correct engineers to them is known as workforce optimization and is a very complex problem, especially when scaled up over large areas. As a result of the vast search space, given by this problem, meta heuristics like genetic algorithms and multi-objective genetic algorithms, are used to find solutions to the problem in reasonable time. However, the hardware these algorithms run on can play a big part in their day-to-day use. This is because the environment in which the engineers are working within is changing on a daily bases. This means that there are severe time-restrictions on the optimization process if the working areas were to be optimized every day. One way to tackle this is to move the optimization system to the cloud where the computing resources available are often far greater than personal desktops or laptops. This paper presents our proposed cloud based many objective type-2 fuzzy logic system for mobile field workforce area optimization. The proposed system showed that utilizing cloud computing with multi-threading capabilities significantly reduce the optimization time allowing greater population sizes, which led to improved working area designs to satisfy the faced objectives.