Relative Population Size Research Articles

Multi-species population indices for sets of species including rare, disappearing or newly occurring species

Multi-species indices (MSI) are widely used as ecological indicators and as instruments to inform environmental policies. Many of these indices combine species-specific estimates of relative population sizes using the geometric mean. Because the geometric mean is not defined when values of zero occur, usually only commoner species are included in MSIs and zero values are replaced by a small non-zero value. The latter can exhibit an arbitrary influence on the geometric mean MSI. Here, we show how the compound Poisson and the negative binomial model can be used in such cases to obtain an MSI that has similar features to the geometric mean, including weighting halving and doubling of a species’ population equally. In contrast to the geometric mean, these two statistical models can handle zero values in population sizes and thus accommodate newly occurring and temporarily or permanently disappearing species in the MSI. We compare the MSIs obtained by the two statistical models with the geometric mean MSI and measure sensitivity to changes in evenness and to population trends in rare and abundant species. Additionally, we outline sources of uncertainty and discuss how to measure them. We found that, in contrast to the geometric mean and the negative binomial MSI, the compound Poisson MSI is less sensitive to changes in evenness when total abundance is constant. Further, we found that the compound Poisson model can be influenced more than the other two methods by trends of species showing a low interannual variance. The negative binomial MSI is less sensitive to trends in rare species compared with the other two methods, and similarly sensitive to trends in abundant species as the geometric mean. While the two new MSIs have the advantage that they are not arbitrarily influenced by rare, newly appearing and disappearing species, both do not weight all species equally. We recommend replacing the geometric mean MSI with either compound Poisson or negative binomial when there are species with a population size of zero in some years having a strong influence on the geometric mean MSI. Further, we recommend providing additional information alongside the MSIs. For example, it is particularly important to give an evenness index in addition to the compound Poisson MSI and to indicate the number of disappearing and newly occurring species alongside the negative binomial MSI.

The North American Antiepileptic Drug Pregnancy Registry: A Canadian Subgroup Analysis.

The North American AED Pregnancy Registry (NAAPR) provides crucial data for understanding the risks of antiepileptic drug (AED) exposure in pregnancy. This study aims to quantify the Canadian contribution to NAAPR and compare AED usage in pregnancy in Canada and the USA. Enrollment rate ratios (ERR) to NAAPR, adjusted for the populations of women of childbearing age, were calculated for the USA, Canada, and for the different Canadian provinces. Methods of enrollment to NAAPR and AED usage were compared between the two countries using chi-squared tests. Between 1997 and 2019, 10,215 pregnant women enrolled into NAAPR: 4.1% were Canadian (n = 432, ERR = 0.39, CI95% = 0.35-0.43). Within Canada, no patients were enrolled from the three northern territories or from Prince Edward Island. While fewer patients than expected enrolled from Quebec (ERR = 0.35, CI95% = 0.19-0.58), Nova Scotia had the highest enrollment rate (ERR = 1.55; CI95% = 0.66-3.11). Compared with their American peers, Canadians were less likely to have been enrolled by their healthcare provider and more likely to have been enrolled via social media (p < 0.01). Canadian women were more likely to be taking carbamazepine (24% vs. 15%; p < 0.01) or valproic acid (8% vs. 4%; p < 0.01). The proportion of Canadian enrollees into NAAPR was less than expected based on the relative population size of Canadian women of reproductive age. Greater Canadian enrollment to NAAPR would contribute to ongoing worldwide efforts in assessing the risks of AEDs use in pregnant women and help quantify rates of AED usage, major congenital malformations, and access to subspecialized epilepsy care within Canada.

RAD-tag and mitochondrial DNA sequencing reveal the genetic structure of a widespread and regionally imperiled freshwater mussel, Obovaria olivaria (Bivalvia: Unionidae).

Obovaria olivaria is a species of freshwater mussel native to the Mississippi River and Laurentian Great Lakes‐St. Lawrence River drainages of North America. This mussel has experienced population declines across large parts of its distribution and is imperiled in many jurisdictions. Obovaria olivaria uses the similarly imperiled Acipenser fulvescens (Lake Sturgeon) as a host for its glochidia. We employed mitochondrial DNA sequencing and restriction site‐associated DNA sequencing (RAD‐seq) to assess patterns of genetic diversity and population structure of O. olivaria from 19 collection locations including the St. Lawrence River drainage, the Great Lakes drainage, the Upper Mississippi River drainage, the Ohioan River drainage, and the Mississippi Embayment. Heterozygosity was highest in Upper Mississippi and Great Lakes populations, followed by a reduction in diversity and relative effective population size in the St. Lawrence populations. Pairwise F ST ranged from 0.00 to 0.20, and analyses of genetic structure revealed two major ancestral populations, one including all St. Lawrence River/Ottawa River sites and the other including remaining sites; however, significant admixture and isolation by river distance across the range were evident. The genetic diversity and structure of O. olivaria is consistent with the existing literature on Acipenser fulvescens and suggests that, although northern and southern O. olivaria populations are genetically distinct, genetic structure in O. olivaria is largely clinal rather than discrete across its range. Conservation and restoration efforts of O. olivaria should prioritize the maintenance and restoration of locations where O. olivaria remain, especially in northern rivers, and to ensure connectivity that will facilitate dispersal of Acipenser fulvescens and movement of encysted glochidia.

Resilient Urban Form: A Case Study on Denizli, Gaziantep and Muğla

Purpose This study identifies whether the hierarchy, development type, and city size have a crucial effect on resilience in ecological terms. Is there a desirable optimum urban form for resilience? The study aims to answer this question by comparing different types of macroform and density of some selected cities in Turkey. Design/Methodology/Approach Denizli, Muğla, and Gaziantep provinces are selected according to the comparability of their population size and urban forms in relation to the greenhouse gas emissions of each city. A retrospective causal comparison method was used in the study. Using the Corine Land Cover Classes program, the change of the artificial surfaces and the city structure between 1990 and 2018 were mapped and detailed graphics were created. Findings Findings show that greenhouse gas (GHG) emissions originating from road transport in Muğla, which has a multi-centered form, were the highest. The surprising result is that Gaziantep has lower GHG emission rate than Denizli although its population is twice the latter. The emission rates of the housing and services sectors were compared with the household size. Gaziantep having the largest household size has the lowest emission rate in this sector. The paper suggests that a hierarchical urban system structure is essential for the resilience of the city to be able to organize itself more effectively, adapt to external changes faster, and create a stronger and more complex structure. City size is an important criterion for low infrastructure cost, efficient use of resources, and capacity to access capital of all kinds. Yet, this criterion may differ in the resilience of the city depending on several factors such as population, area size, and distribution of various urban functions. The development type, on the other hand, is highly effective on GHG emissions as the monocentric cities generate fewer emissions than the polycentric cities. Research Limitations/Implications The GHG reports created for the case areas consisted of different years and different analysis units. This limits the sectors to which cities can be compared. Originality/Value This article is a detailed and original study in terms of evaluating the resilience of Turkish cities with different morphologies.

Molecular interaction and partitioning in α-keratin using 1H NMR spin-lattice (T1) relaxation times.

The interactions between small molecules and keratins are poorly understood. In this paper, a nuclear magnetic resonance method is presented to measure changes in the 1H T1 relaxation times of small molecules in human hair keratin to quantify their interaction with the fibre. Two populations of small-molecule compounds were identified with distinct relaxation times, demonstrating the partitioning of the compounds into different keratin environments. The changes in relaxation time for solvent in hair compared with bulk solvent were shown to be related to the molecular weight (MW) and the partition coefficient, LogP, of the solvent investigated. Compounds with low MWs and high hydrophilicities had greater reductions in their T1 relaxation times and therefore experienced increased interactions with the hair fibre. The relative population sizes were also calculated. This is a significant step towards modelling the behaviour of small molecules in keratinous materials and other large insoluble fibrous proteins.

Vaccination and herd immunity thresholds in heterogeneous populations.

It has been suggested, without rigorous mathematical analysis, that the classical vaccine-induced herd immunity threshold (HIT) assuming a homogeneous population can be substantially higher than the minimum HIT obtained when considering population heterogeneities. We investigated this claim by developing, and rigorously analyzing, a vaccination model that incorporates various forms of heterogeneity and compared it with a model that considers a homogeneous population. By employing a two-group vaccination model in heterogeneous populations, we theoretically established conditions under which heterogeneity leads to different HIT values, depending on the relative values of the contact rates for each group, the type of mixing between the groups, the relative vaccine efficacy, and the relative population size of each group. For example, under biased random mixing assumption and when vaccinating a given group results in disproportionate prevention of higher transmission per capita, we show that it is optimal to vaccinate that group before vaccinating the other groups. We also found situations, under biased assortative mixing assumption, where it is optimal to vaccinate more than one group. We show that regardless of the form of mixing between the groups, the HIT values assuming a heterogeneous population are always lower than the HIT values obtained from a corresponding model with a homogeneous population. Using realistic numerical examples and parametrization (e.g., assuming assortative mixing together with vaccine efficacy of 95% and the value of the basic reproduction number, {mathcal{R}}_{0}, of the model set at {mathcal{R}}_{0}= 2.5), we demonstrate that the HIT value generated from a model that considers population heterogeneity (e.g., biased assortative mixing) is significantly lower (40%) compared with a HIT value of 63% obtained if the model uses homogeneous population.

On computing relative effective population size estimates and parameters from an equilibrium cycle of hermaphrodite frequency fluctuation due to mixed reproductive modes in filamentous fungi

Many filamentous ascomycete fungi reproduce primarily asexually, with only occasional sexual generations. This can lead to a departure from the 1:1 mating type ratio that is expected in obligate sexual populations. The relaxed selection on sexual traits also can lead to a decrease in the frequency of female fertile strains in field populations, while male fertility does not similarly decrease since male gametes also can serve as asexual spores. Both changes ultimately impact the strength of genetic drift in populations. The frequency of female sterility likely increases with the time since the last generation of sexual reproduction, such that it can be used to estimate the relative frequency of sexual reproduction. Here I provide additional details relevant to Leslie and Klein’s (1996) model of mixed sexual reproduction and vegetative propagation as related to the frequency of female sterility. This includes new or modified equations that allow for simpler calculations of i) two estimates of relative Ne, ii) the expected range of hermaphrodite frequencies during the cycles of mixed reproduction, and iii) the relative frequency of sex. These equations also are included in spreadsheet templates into which researchers can directly enter frequencies computed from their population data to estimate these parameters for their own populations. These resources will make the results of Leslie and Klein (1996) more accessible and should increase the use of this model in evaluating the frequency of sexual reproduction of filamentous fungi.

Are Patients Aware of Their Rights? A Cross-Sectional Study of Visitors to Three Primary Healthcare Centers in Riyadh, Saudi Arabia.

Background and objectivePatients’ rights are an essential aspect of human rights. Thus, in Saudi Arabia, the Ministry of National Guard Health Affairs (MNGHA) established a Patients’ Bill of Rights (PBR) and introduced it to the public about 30 years ago. This study aims to assess levels of awareness of PBR and to identify their information sources among visitors to primary healthcare centers (PHCCs).MethodsThis cross-sectional study included 358 visitors, aged 17 to 78, to three PHCCs at the National Guard Hospital in Riyadh, Saudi Arabia. The study was conducted between April and December 2017 using a self-administered questionnaire. The initial sample (convenience sampling) was refined to match the proportion of participants with the relative size of populations served by the centers. Descriptive statistics were used to determine the relationships between participants’ demographic data and levels of awareness of patients' rights.ResultsMost participants (72.2%) were moderately aware of their rights, but the majority (65.3%) were unaware of the existence of the PBR. Healthcare providers were the main information source for patients’ rights, although participants with the highest awareness scores obtained information from social media. Level of awareness was significantly associated with education, income, and regular hospital follow-ups.ConclusionsThe study results should motivate healthcare providers, stakeholders, and health organizations in Saudi Arabia to raise and maintain public awareness of patients’ rights and to implement them.

Blue water footprint caps per sub-catchment to mitigate water scarcity in a large river basin: The case of the Yellow River in China

The amount of groundwater and surface water consumed in a river basin constitutes the blue water footprint (BWF). To safeguard the environment, it has been suggested to set a cap to the BWF based on blue water availability (BWA). BWA depends on the precipitation that becomes runoff and the need to reserve environmental flow requirements. Previous studies determined BWF caps based on the use-what-is-there principle, which assumes that all BWA in a sub-catchment may be consumed locally, without the need to reserve water for downstream. However, BWA in an upstream sub-catchment does not have to be consumed locally but could be consumed downstream instead, thereby mitigating blue water scarcity in downstream areas. Therefore, this study aims to investigate the effect of alternative allocation principles – that account for downstream demands – to set monthly BWF caps per sub-catchment on BWS levels across a large river basin. We take the Yellow River basin for the period 2010 to 2014 as a case study to evaluate four scenarios of BWF cap-setting. We compare the ‘natural’ and ‘reservoir’ scenario that both apply the use-what-is-there principle to determine the effects of reservoirs on BWF caps. We then apply two alternative allocation principles that take relative population size (‘population-based’ scenario) and historic blue water demand (‘demand-based’ scenario) as a basis to determine BWF caps per sub-catchment and compare the effects against the ‘reservoir’ scenario. Our results confirm previous findings on the effects of reservoirs on caps. We further find that blue water scarcity increases from upstream to downstream under the use-what-is-there principle. Both the population- and demand-based scenarios reduce upstream-downstream differences in the degree of blue water scarcity. The demand-based scenario is most effective in this respect. On the other hand, the population-based scenario leads to the smallest upstream-downstream differences in BWA per capita. The results feed into a discussion on alternative approaches to set BWF caps in a large river basin which needs to take place for BWF caps to become effective and practical concepts in policy making.

Whither the science in wildlife management?

Whither the science in wildlife management?

Infective prey leads to a partial role reversal in a predator-prey interaction.

An infective prey has the potential to infect, kill and consume its predator. Such a prey-predator relationship fundamentally differs from the predator-prey interaction because the prey can directly profit from the predator as a growth resource. Here we present a population dynamics model of partial role reversal in the predator-prey interaction of two species, the bottom dwelling marine deposit feeder sea cucumber Apostichopus japonicus and an important food source for the sea cucumber but potentially infective bacterium Vibrio splendidus. We analyse the effects of different parameters, e.g. infectivity and grazing rate, on the population sizes. We show that relative population sizes of the sea cucumber and V. Splendidus may switch with increasing infectivity. We also show that in the partial role reversal interaction the infective prey may benefit from the presence of the predator such that the population size may exceed the value of the carrying capacity of the prey in the absence of the predator. We also analysed the conditions for species extinction. The extinction of the prey, V. splendidus, may occur when its growth rate is low, or in the absence of infectivity. The extinction of the predator, A. japonicus, may follow if either the infectivity of the prey is high or a moderately infective prey is abundant. We conclude that partial role reversal is an undervalued subject in predator-prey studies.

Assessing (a)symmetry in multilingualism: The case of Mano and Kpelle in Guinea

Aims and objectives: The paper studies Kpelle–Mano bilingualism in the broader context of local multilingual repertoires and assesses symmetry in the patterns of language use. Methodology: We combine natural speech sampling with ethnographic observations, interviews, sociolinguistic surveys and elicitation tasks. Data and analysis: The data analyzed includes 88 questionnaire responses, targeted elicitation with 21 individuals, as well as corpus collection and ethnographic observations over the course of fieldwork from 2008 onwards. Findings: Neither Mano nor Kpelle has an overt prestige value. Marriage patterns and economic activity are symmetrical, and both languages can be in certain cases chosen as a means of interethnic communication. However, bilingualism is typically unreciprocated, and the Mano speak Kpelle more often than the other way round. Contact-induced change is almost exclusively unidirectional, with Kpelle influencing Mano. We suggest relative population size as the main explanatory factor. In contrast, both Mano and Kpelle are in an asymmetric relationship with Maninka, which is frequently used by urban Mano and Kpelle speakers. Even if some Maninka claim to speak Kpelle to a certain extent, they rarely use it in real life. Originality: This paper is a report on a previously unstudied multilingual setting. We stress the theoretical and the empirical importance of the patrilect. In addition to its being the defining identity feature, the patrilect is also the main predictor defining the language choice in communication and the volume of the repertoire. Significance: We applied long-term participant observation in various social settings to obtain a fine-grained account of the rules governing language choice, which a typical background questionnaire would overlook. We also sampled natural and elicited speech of L1 and L2 speakers of Mano and Kpelle, a method that yields better results than proficiency tests because it captures interference in grammar, which has far-reaching consequences for contacting languages.

SPECIES COMPOSITION AND RELATIVE POPULATION SIZE OF FISHES IN THE OSTER RIVER (THE DESNA RIVER BASIN): 50 YEARS ANALYSIS

Inroduction. Changes in the species composition and population size of freshwater fihes are determined by deformations of the habitat in Ukraine and are characterized by a pronounced negative dynamics. Deformation of ichthyofauna is caused by extinction of a number of aboriginal fihes and emergence of alien species.Aim. To establish the current species composition and relative population size of fih species in the Oster River and the dynamics of these characteristics over a 50-yearlong period in the context of negative transformations of the ichthyofauna of the rivers of Ukraine.Results. Comparative study of the species composition and relative population size of fih species in the fih catches by small-river fihing gear in the Oster river was conducted during the period since 1971-72 till 2019. During this time considerable changes in species composition took place. The following species disappeared from the catches: Leuciscus leuciscus, Leuciscus idus, Chondrostoma nasus, Carassius carassius, Blicca bojerkna and Neogobius flviatilis, they were replaced by three invasion species (Percottus glenni, Pseudorasbora parva, Proterorhinus marmoratus). The changes in the dominant species took place, thus, in the Oster ichthyocene the species with the short life cycle started to prevail, the share of invasion species increased from 1.4 to 37%, and the share of initial marine fih among them is very low. The comparison with the river systems of the Stugna and the Lower Dnipro represents the fact that the mentioned negative tendencies are common for the whole Dnipro system, however the situation in the Lower Dnipro must be considered less critical than in the Oster and the Stugna rivers. The fact that the catches of industrial fih decreased more than 10 times in the Desna river during this period of time gives the reason to consider that the dramatic reduction of the absolute number of their populations occurred in the Oster river as well. That is why even relatively safe species (Abramis brama, Rutilus ritilus, Scardinius erythrophthalmus, Esox lucius, Perca flviatilis, Alburnus alburnus, Squalius cephalus) are in critical situation in this transformed river system.Сonclusions. In the ichthyocene of the Oster River over a 50-year period there have been signifiant changes in species composition, relative and absolute population numbers associated with the extinction and reduction of population sizes of rheophilic species and fih that are adapted to life in the flodplain. The modern Oster River is dominated by invasive and short-cycle species. The obtained tendencies in the dynamics of the ichthyofauna of the Oster River are similar to the nature of changes in other river systems of Ukraine, although they occur at a faster pace, which is characteristic of the smallest plain rivers.

Approximate Bayesian Computation of radiocarbon and paleoenvironmental record shows population resilience on Rapa Nui (Easter Island)

Examining how past human populations responded to environmental and climatic changes is a central focus of the historical sciences. The use of summed probability distributions (SPD) of radiocarbon dates as a proxy for estimating relative population sizes provides a widely applicable method in this research area. Paleodemographic reconstructions and modeling with SPDs, however, are stymied by a lack of accepted methods for model fitting, tools for assessing the demographic impact of environmental or climatic variables, and a means for formal multi-model comparison. These deficiencies severely limit our ability to reliably resolve crucial questions of past human-environment interactions. We propose a solution using Approximate Bayesian Computation (ABC) to fit complex demographic models to observed SPDs. Using a case study from Rapa Nui (Easter Island), a location that has long been the focus of debate regarding the impact of environmental and climatic changes on its human population, we find that past populations were resilient to environmental and climatic challenges. Our findings support a growing body of evidence showing stable and sustainable communities on the island. The ABC framework offers a novel approach for exploring regions and time periods where questions of climate-induced demographic and cultural change remain unresolved.

Intensive monitoring for bees in North America: indispensable or improvident?

AbstractContinued reports of bee declines have prompted repeated calls for a national monitoring programme in the United States. Here, we argue that such a large‐scale surveillance monitoring programme would consume inordinate resources without providing the sought‐after data in a meaningful time period.Surveillance monitoring cannot provide reliable and timely measures of absolute or relative population size, species richness or diversity, host plant and nest site preferences or typical foraging ranges. In addition, the multitude of specimens captured by the passive traps commonly used to surveil overwhelm our identification capacity and, in some cases, may even accelerate species decline.Conversely, surveillance monitoring should be pursued when data can be collected non‐lethally for readily identifiable species or species groups (e.g., bumble bees) or when widely distributed sentinel plants can be observed (e.g., sunflowers). Lethal collections should continue at appropriate temporal intervals but only at a limited number of representative areas with accurate historic records.We advocate that emphasis be placed on a targeted, natural‐history approach aimed at addressing specific hypotheses and exploring solutions to conservation management problems. We already know enough about the drivers of bee decline to formulate and test potential solutions. While additional information is of value in understanding bee diversity, distributions and evolution, we do not need it to begin to take action; we should be focusing on the best ways to help bee species endure rather than attempting to accumulate even more evidence that they are in trouble.

Dilution and amplification effects in Lyme disease: Modeling the effects of reservoir-incompetent hosts on Borrelia burgdorferi sensu stricto transmission

The literature on Lyme disease includes a lively debate about the paradoxical role of changing deer populations. A decrease in the number of deer will both (1) reduce the incidence of Lyme disease by decreasing the host populations for ticks and therefore tick populations, and (2) enhance the incidence of Lyme disease by offering fewer reservoir-incompetent hosts for ticks, forcing the vector to choose reservoir-competent, and therefore possibly diseased, hosts to feed on. A review of field studies exploring the net impact of changing deer populations shows mixed results. In this manuscript, we investigate the hypothesis that the balance of these two responses to changing deer populations depends on the relative population sizes of reservoir-competent vs. reservoir-incompetent hosts and the presence of host preference in larval and adult stages.A temperature driven seasonal model of Borrelia burgdorferi sensu stricto (cause of Lyme disease) transmission among three host types (reservoir-competent infected and uninfected hosts, and reservoir-incompetent hosts) is constructed as a system of nonlinear ordinary differential equations. The model, which produces biologically reasonable results for both the tick vector Ixodes scapularis Say 1921 and the hosts, is used to investigate the effects of reservoir-incompetent host removal on both tick populations and disease prevalence for various relative population sizes of reservoir-competent hosts vs. reservoir-incompetent hosts.In summary, the simulation results show that the model with host preference appears to be more accurate than the one with no host preference. Given these results, we found that removal of adult I. scapularis(Say) hosts is likely to reduce questing nymph populations. At very low levels questing adult abundance may rise with lack of adult hosts. There is a dilution effect at low reservoir-competent host populations and there is an amplification effect at high reservoir-competent host populations.

Long-term and large-scale multispecies dataset tracking population changes of common European breeding birds

Around fifteen thousand fieldworkers annually count breeding birds using standardized protocols in 28 European countries. The observations are collected by using country-specific and standardized protocols, validated, summarized and finally used for the production of continent-wide annual and long-term indices of population size changes of 170 species. Here, we present the database and provide a detailed summary of the methodology used for fieldwork and calculation of the relative population size change estimates. We also provide a brief overview of how the data are used in research, conservation and policy. We believe this unique database, based on decades of bird monitoring alongside the comprehensive summary of its methodology, will facilitate and encourage further use of the Pan-European Common Bird Monitoring Scheme results.

Grizzled Skippers stuck in the south: Population‐level responses of an early‐successional specialist butterfly to climate across its UK range over 40 years

AbstractAimClimate change has been predicted to facilitate poleward expansion of many early‐successional specialist invertebrates. The Grizzled Skipper, Pyrgus malvae, is a threatened butterfly in long‐term decline that has not met expectations of northern expansion in Britain, possibly indicating that climate change has not improved northern habitat suitability or that another driver (e.g. land use change) is masking its effects. Here, we explore the effect of climate on population size trends over four decades, and whether any regions show an improving population trend that may be a precursor to northern expansion. Examining detailed spatio‐temporal abundance data can reveal unexpected limitations to population growth that would not be detectable in widely used climate envelope models.LocationCentral and southern England.MethodsMixed models were used to investigate P. malvae population size in relation to time and monthly climate measures across its UK range since 1976, based on repeated transect walks.ResultsWe found that P. malvae population size declined more over time in the north and west of its UK range than in the south and east, and was negatively related to high December temperature and summer rainfall. However, the effect sizes of temperature and rainfall were minimal.Main ConclusionsThe last 40 years of climate change have not ameliorated climate suitability for P. malvae at its range edge, contrary to expectations from spatial‐only climate envelope models. The clear long‐term downward trends in population size are independent of climate change and we propose probably due to habitat deterioration. Our findings highlight potential hazards in predicting species range expansions from spatial models alone. Although some climate variables may be associated with a species’ distribution, other factors may be more dominant drivers of trends and therefore more useful predictors of range changes.

Horizontal interactions in local personal income taxes

Theories of inter-jurisdictional tax and yardstick competition assume that the tax decisions of one jurisdiction will influence the tax decisions of other jurisdictions. This paper empirically addresses the issue of horizontal dependence in local personal income tax rates across jurisdictions. Based on a large data set covering Swedish municipalities over a period of 14 years, we test for interactions across municipalities that share a common border, across municipalities within a distance of 100 km of each other, and across municipalities with similar political representation in the local council. We also test the hypothesis that the tax rate of relatively larger municipalities has a greater influence on their neighbors' tax rate compared to the influence of their smaller neighbors. Our results suggest that when lagged tax rates are controlled for, the horizontal correlation across municipalities that share a common border or are within a distance of 100 km from each other becomes insignificant. This result is of importance as it suggests that lagged tax rates should be included or at least tested for when testing for horizontal interactions or mimicking in local tax rates. However, our results support the hypothesis of horizontal interactions across municipalities that share a common border when the influence of neighboring municipalities is also weighted by their relative population size, i.e. relatively larger neighbors tend to have a greater impact on their neighbor's tax rates than their relatively smaller neighbors. This is of importance as it suggests that distance or proximity matters, although only in combination with the relative population size. We also find some evidence of horizontal dependence across municipalities with similar political preferences.

Nation-Wide Viral Sequence Analysis of HIV-1 Subtype B Epidemic in 2003-2012 Revealed a Contribution of Men Who Have Sex With Men to the Transmission Cluster Formation and Growth in Japan.

Background: To better understand the epidemiology of human immunodeficiency virus type 1 (HIV-1) subtype B transmission in Japan, phylodynamic analysis of viral pol sequences was conducted on individuals newly diagnosed as HIV-1 seropositive.Methodology: A total of 5,018 patients newly diagnosed with HIV-1 infection and registered in the Japanese Drug Resistance HIV Surveillance Network from 2003 to 2012 were enrolled in the analysis. Using the protease-reverse transcriptase nucleotide sequences, their subtypes were determined, and phylogenetic relationships among subtype B sequences were inferred using three different methods: distance-matrix, maximum likelihood, and Bayesian Markov chain Monte Carlo. Domestically spread transmission clusters (dTCs) were identified based on the following criteria: >95% in interior branch test, >95% in Bayesian posterior probability and <10% in depth-first searches for sub-tree partitions. The association between dTC affiliation and individuals' demographics was analyzed using univariate and multivariate analyses.Results: Among the cases enrolled in the analysis, 4,398 (87.6%) were classified as subtype B. Many of them were Japanese men who had sex with men (MSM), and 3,708 (84.3%) belonged to any of 312 dTCs. Among these dTCs, 243 (77.9%) were small clusters with <10 individuals, and the largest cluster consisted of 256 individuals. Most dTCs had median time of the most recent common ancestor between 1995 and 2005, suggesting that subtype B infection was spread among MSMs in the second half of the 1990s. Interestingly, many dTCs occurred within geographical regions. Comparing with singleton cases, TCs included more MSM, young person, and individuals with high CD4+ T-cell count at the first consultation. Furthermore, dTC size was significantly correlated with gender, age, transmission risks, recent diagnosis and relative population size of the region mainly distributed.Conclusions: Our study clarified that major key population of HIV-1 subtype B epidemic in Japan is local MSM groups. The study suggests that HIV-1 subtype B spread via episodic introductions into the local MSM groups, some of the viruses spread to multiple regions. Many cases in dTC were diagnosed during the early phase of infection, suggesting their awareness to HIV risks.