Establishment Of Populations Research Articles

Reproductive compatibility of a newly imported Australian population of the biocontrol agent Anaphes nitens with an existing South African population

Introductions of natural enemies in classical biocontrol programs potentially cause genetic bottlenecks which can be detrimental for biocontrol. This can be mitigated by introducing multiple populations of a natural enemy, but thorough pre-release testing is needed to ensure compatibility. In this study compatibility between an established population of Anaphes nitens in South Africa and a newly imported A. nitens population from Australia was tested. Anaphes nitens is an egg parasitoid of Gonipterus sp. n. 2, an important pest in Eucalyptus plantations. South African and Australian A. nitens lineages were compared to two admixed lineages, which were reared from the F0 to the F2 generation. No differences were found in the proportion of replicates producing offspring overall, or female offspring specifically, indicating there was no sexual isolation between the populations. The typical symptoms of cytoplasmic incompatibility in haplodiploids, namely male biased sex ratios, were not observed. The lack of significant differences in fecundity and development time between the lineages suggested that there was no hybrid vigour or outbreeding depression. We conclude that a field release of the imported A. nitens population poses a low risk of disrupting the existing biocontrol program due to reproductive barriers or outbreeding depression. Whether there is a benefit of adding the newly imported Australian A. nitens population to the existing biocontrol system in South Africa needs to be studied further, for example by performing a field release combined with post-release assessments for determining establishment and spread.

Forensic parameters and population structure based on 21 autosomal STRs with the investigator 24plex QS in mestizos from the Mexico City population

Allele frequencies and forensic parameters for 21 STR autosomal markers (CSF1PO, D10S1248, D12S391, D13S317,D16S539, D18S51, D19S433, D1S1656,D21S11, D22S1045, D2S1338, D2S441, D3S1358, D5S818, D7S820, D8S1179, FGA, SE33, TH01, TPOX and vWA) were reported in 289 unrelated individuals from Mexico City, Mexico. In addition, an interpopulation analysis was performed including other world populations. In brief, the established population database of 21 autosomal STR markers in the present work is adequate for human identification purposes.

Environmental favorability models as a tool to support trophic rewilding initiatives

Trophic rewilding is considered a conservation measure that aims to restore the trophic interactions. In north‐central Portugal, the Iberian wolf (Canis lupus signatus) is endangered mainly due to human persecution, triggered by wolf depredation on livestock. Several initiatives have occurred in this area to increase wolf wild prey availability by reintroducing/reinforcing roe deer (Capreolus capreolus) populations. However, the success of trophic rewilding initiatives relies on up‐to‐date scientific evidence, considering both ecological and social settings. Favorability models can be used to infer the most suitable habitats for roe deer settlement and expansion by analyzing the environmental variables known to influence species ecology and behavior. In this study, we infer how the prey habitat favorability can contribute to plan prey populations reinforcement processes as a tool for trophic chain restoration. Using 330 camera traps, we monitored the roe deer population over 8,940 km2 in north‐central Portugal. Field data were used to evaluate the environmental determinants of roe deer presence. By using the favorability function, we created a spatially explicit gradient of habitat favorability that allowed us to define key areas for the application of management measures. The selected sites are strategically positioned to promote the natural expansion of established roe deer populations and overlap the current distribution of Iberian wolf. These results are an important step toward the restoration of the trophic chain and to reduce human–wolf conflicts. Our proposal paves the way for future rewilding initiatives, especially where prey species are central to the survival of top predators.

Evaluation of fluopyram for disease and root knot nematode control along with yield response on peanut

Efficacy of in-furrow application of fluopyram + imidacloprid alone or followed by fluopyram + prothioconazole at-pegging and aldicarb for managing peanut root-knot nematode populations, root and pod galling due to nematodes, and yield, along with non-target effects on leaf spot diseases and stem rot were compared on the root-knot susceptible cultivar Georgia-06G over seven years on an irrigated site with an established population of Meloidogyne arenaria race 1. In all years, fungicides were applied to all plots following a Peanut Rx application schedule. Root-knot nematode populations, nematode damage, and yield along with leaf spot severity and stem rot incidence significantly differed among years; except for nematode populations, these measured variables also differed by nematicide treatment. Averaged over years, galling and root damage was significantly reduced with aldicarb compared to the no-nematicide control but not with either of the fluopyram treatments. While similar late-season root-knot nematode populations were noted for all nematicide programs and the non-treated control, pooled over years, significant yield gains were obtained with aldicarb and fluopyram programs with the two-treatment program providing greater yields than the aldicarb treatment. Leaf spot severity, averaged over years, was similar in aldicarb and control treatments; however, both fluopyram treatments had significantly lower leaf spot severity than the aldicarb treatment. Stem rot incidence did not differ among nematicide treatments. In addition, pooled over years, there was a negative relationship between juvenile populations and yield, but this was relatively weak. Weather, particularly extreme rain conditions, impacted yield directly as well as indirectly by affecting leaf spot severity and nematode activity.

High promiscuity among females of the invasive pest species Drosophila suzukii.

Drosophila suzukii (Matsumura, 1931), the spotted-wing drosophila, is a highly invasive fruit fly that spread from Southern Asia across most regions of Asia and, in the last 15 years, has invaded Europe and the Americas. It is an economically important pest of small fruits such as berries and stone fruits. Drosophila suzukii speciated by adapting to cooler, mountainous, and forest environments. In temperate regions, it evolved seasonal polyphenism traits which enhanced its survival during stressful winter population bottlenecks. Consequently, in these temperate regions, the populations undergo seasonal reproductive dynamics. Despite its economic importance, no data are available on the behavioural reproductive strategies of this fly. The presence of polyandry, for example, has not been determined despite the important role it might play in the reproductive dynamics of populations. We explored the presence of polyandry in an established population in Trentino, a region in northern Italy. In this area, D. suzukii overcomes the winter bottleneck and undergoes a seasonal reproductive fluctuation. We observed a high remating frequency in females during the late spring demographic explosion that led to the abundant summer population. The presence of a high degree of polyandry and shared paternity associated with the post-winter population increase raises the question of the possible evolutionary adaptive role of this reproductive behaviour in D. suzukii.

Pain and incident cognitive impairment in very old Mexican American adults.

Studies have investigated the association between pain and cognitive impairment among older adults, but the findings are mixed. We assessed the relationship of activity-limiting pain (pain interference) with incident cognitive impairment and the mediating effect of depressive symptoms among Mexican American adults aged ≥80. Data were taken from the Hispanic Established Population for the Epidemiological Study of the Elderly (2010-2016). Pain interference, or pain that limited daily activities in the last 12 months, was categorized into none, untreated pain interference, and treated pain interference. Cognitive impairment was defined as scoring <21 on the Mini-Mental State Examination and difficulty with at least one instrumental activity of daily living. We used general estimation equations to assess this relationship between pain and incident cognitive impairment over the 6-year period (n = 313). Participants reporting both untreated and treated pain interference had higher odds of incident cognitive impairment than those reporting no pain or pain interference (untreated adjusted odds ratio [aOR]: 2.18; 95% confidence interval [CI]: 1.09-4.36; treated aOR: 1.99; 95% CI: 1.15-3.44). Depressive symptoms explained 15.0% of the total effect of untreated pain and 25.3% of treated pain. Among very old Mexican American adults, both treated and untreated pain interference was associated with incident cognitive impairment. This association was partially mediated by depressive symptoms, underscoring a need for depression screening in patients with chronic pain. Future work is needed to examine mechanistic/causal pathways between pain and subsequent cognitive impairment and the role of pharmacological and non-pharmacological treatments in these pathways.

Cultural adaptation and demographic change: evidence from Mexican-American naming patterns after the California Gold Rush

ABSTRACT According to new assimilation theory, assimilation can entail not only the adoption, by immigrants, of the established population's cultural practices, but also the adoption, by the established population, of immigrants' cultural practices. However, empirical research on assimilation has either neglected adaptation on the part of the established population or identified only modest changes. We examine reactions to a massive and rapid inflow of immigrants, and specifically, those of Mexican-origin Californios around the time of the Gold Rush of 1849. Treating naming patterns as indicators of assimilation, we find that Mexican American children born in California after 1849 were significantly less likely to receive distinctively Hispanic first names. As a placebo test, we further show that a similar pattern does not obtain in areas (e.g. New Mexico) that did not experience a rapid inflow of new American settlers. The findings validate an important insight of new assimilation theory, as well as shed new light on contemporary research on demographic change.

Genetic mixing in conservation translocations increases diversity of a keystone threatened species, Bettongia lesueur.

Translocation programmes are increasingly being informed by genetic data to monitor and enhance conservation outcomes for both natural and established populations. These data provide a window into contemporary patterns of genetic diversity, structure and relatedness that can guide managers in how to best source animals for their translocation programmes. The inclusion of historical samples, where possible, strengthens monitoring by allowing assessment of changes in genetic diversity over time and by providing a benchmark for future improvements in diversity via management practices. Here, we used reduced representation sequencing (ddRADseq) data to report on the current genetic health of three remnant and seven translocated boodie (Bettongia lesueur) populations, now extinct on the Australian mainland. In addition, we used exon capture data from seven historical mainland specimens and a subset of contemporary samples to compare pre-decline and current diversity. Both data sets showed the significant impact of population founder source (whether multiple or single) on the genetic diversity of translocated populations. Populations founded by animals from multiple sources showed significantly higher genetic diversity than the natural remnant and single-source translocation populations, and we show that by mixing the most divergent populations, exon capture heterozygosity was restored to levels close to that observed in pre-decline mainland samples. Relatedness estimates were surprisingly low across all contemporary populations and there was limited evidence of inbreeding. Our results show that a strategy of genetic mixing has led to successful conservation outcomes for the species in terms of increasing genetic diversity and provides strong rationale for mixing as a management strategy.

Diabetes Complications and Pain Among Mexican Americans Aged 80 and Older.

Diabetes is common among Hispanic older adults; however, the association between diabetic complications and pain has not been widely studied in this population. Our objective was to examine the association between diabetes complications and pain over 6 years among Mexican Americans aged 80 years and older. We used data from Waves 7 to 9 (2010-2016) of the Hispanic Established Population for the Epidemiologic Study of the Elderly (n = 853). Participants were categorized as having no diabetes, diabetes without complications, and diabetes with complications. Pain was defined as reporting pain when standing or walking (pain on weight-bearing) and having pain that limited daily activities (pain interference). We used generalized estimating equations to estimate the odds of pain over 6 years as a function of diabetes status controlling for socioeconomic and health characteristics. At baseline, the mean age was 85.7 (standard deviation = 3.9) years, 65.2% female, 68.5% had no diabetes, 14.7% had diabetes without complications, and 16.9% had diabetes with complications. Those with diabetes without complications had lower odds of reporting pain on weight-bearing and pain interference, compared to those with no diabetes. Among those reporting diabetes (n = 269), those with complications had higher odds of pain on weight-bearing and pain interference, compared to those without complications. Those with both micro and macro complications had over 2 times the odds of pain, compared to those having no complications. The lower burden of pain in those with diabetes but no complications may reflect optimal management of diabetes. Routine screening and treatment of pain in patients with diabetes complications can mitigate excess disability and increase the quality of life for patients with diabetes.

Conserved islands of divergence associated with adaptive variation in sockeye salmon are maintained by multiple mechanisms.

Local adaptation is facilitated by loci clustered in relatively few regions of the genome, termed genomic islands of divergence. The mechanisms that create and maintain these islands and how they contribute to adaptive divergence is an active research topic. Here, we use sockeye salmon as a model to investigate both the mechanisms responsible for creating islands of divergence and the patterns of differentiation at these islands. Previous research suggested that multiple islands contributed to adaptive radiation of sockeye salmon. However, the low-density genomic methods used by these studies made it difficult to fully elucidate the mechanisms responsible for islands and connect genotypes to adaptive variation. We used whole genome resequencing to genotype millions of loci to investigate patterns of genetic variation at islands and the mechanisms that potentially created them. We discovered 64 islands, including 16 clustered in four genomic regions shared between two isolated populations. Characterisation of these four regions suggested that three were likely created by structural variation, while one was created by processes not involving structural variation. All four regions were small (< 600 kb), suggesting low recombination regions do not have to span megabases to be important for adaptive divergence. Differentiation at islands was not consistently associated with established population attributes. In sum, the landscape of adaptive divergence and the mechanisms that create it are complex; this complexity likely helps to facilitate fine-scale local adaptation unique to each population.

Multiple introductions and human-aided dispersal of the UK’s most widespread non-native amphibian

The alpine newt Ichthyosaura alpestris has achieved a widespread distribution as a non-native (alien) species in Britain since its initial introduction over a century ago, but the patterns of its release and subsequent dispersal have never yet been collectively analysed. We employed a multi-disciplinary combination of methods, using geographic profiling to estimate the likely number and locations of introductions, and mitochondrial DNA polymorphisms to investigate the likely geographic source of primary introductions, including the potential role of the pet trade. In parallel we used population genetic analysis and coalescence-based modelling to infer the demographics and directionality of dispersal from founding populations. Our results show that alpine newts have been released at multiple sites. We found a close resemblance between patterns of mtDNA haplotypes in the pet trade and those of established alpine newt populations, suggesting a relationship between trade, releases, and dispersal. Results from demographic modelling using Approximate Bayesian Computation are also consistent with multiple independent introductions with limited local dispersal, and additionally suggest that releases may occur from intermediate sources, such as captive populations. Our results support the hypothesis that deliberate human activity is largely responsible for both introductions of alpine newts into the UK and their wider dispersal post-introduction. The likely involvement of the international pet trade highlights the risk that ongoing releases of I. alpestris may expose native species to pathogens, whether pre-existing or novel.

Development of heat-shock resistance in Legionella pneumophila modeled by experimental evolution.

Because it can grow in buildings with complex hot water distribution systems (HWDS), healthcare facilities recognize the waterborne bacterium Legionella pneumophila as a major nosocomial infection threat and often try to clear the systems with a pasteurization process known as superheat-and-flush. After this treatment, many facilities find that the contaminating populations slowly recover, suggesting the possibility of in situ evolution favoring increased survival in high-temperature conditions. To mimic this process in a controlled environment, an adaptive laboratory evolution model was used to select a wild-type strain of L. pneumophila for survival to transient exposures to temperatures characteristic of routine hot water use or failed pasteurization processes in HWDS. Over their evolution, these populations became insensitive to exposure to 55°C and developed the ability to survive short exposures to 59°C heat shock. Heat-adapted lineages maintained a higher expression of heat-shock genes during low-temperature incubation in freshwater, suggesting a pre-adaptation to heat stress. Although there were distinct mutation profiles in each of the heat-adapted lineages, each acquired multiple mutations in the DnaJ/DnaK/ClpB disaggregase complex, as well as mutations in chaperone htpG and protease clpX. These mutations were specific to heat-shock survival and were not seen in control lineages included in the experimental model without exposure to heat shock. This study supports in situ observations of adaptation to heat stress and demonstrates the potential of L. pneumophila to develop resistance to control measures. IMPORTANCE As a bacterium that thrives in warm water ecosystems, Legionella pneumophila is a key factor motivating regulations on hot water systems. Two major measures to control Legionella are high circulating temperatures intended to curtail growth and the use of superheat-and-flush pasteurization processes to eliminate established populations. Facilities often suffer recolonization of their hot water systems; hospitals are particularly at risk due to the severe nosocomial pneumoniae caused by Legionella. To understand these long-term survivors, we have used an adaptive laboratory evolution model to replicate this process. We find major differences between the mutational profiles of heat-adapted and heat-naïve L. pneumophila populations including mutations in major heat-shock genes like chaperones and proteases. This model demonstrates that well-validated treatment protocols are needed to clear contaminated systems and-in an analog to antibiotic resistance-the importance of complete eradication of the resident population to prevent selection for more persistent bacteria.

Invasive Haemaphysalis longicornis (Acari: Ixodidae) investigation in South Carolina: new records of establishment, pathogen prevalence, and blood meal analyses.

The first established population of the Asian longhorned tick Haemaphysalis longicornis (Neumann, Acari: Ixodidae) was discovered in a northern South Carolina county in June 2022. A coordinated investigation was launched to investigate the invasive tick's pathogen infection prevalence and blood meal preferences. Almost 2,000 Ha. longicornis ticks were collected from one cattle field. A majority of collected ticks had evidence of cattle and dog blood meals, and multiple samples were tested positive for Borrelia burgdorferi s.l. and Theileria orientalis-first reports for these pathogens in this tick species in South Carolina. This investigation was the direct result of a collaborative education campaign and tick surveillance program launched earlier in the year with multiple state partners.

Variations in Otolith and Scale Shape of the Invasive Round Goby Neogobius melanostomus Populations from Different Habitats of the Sava River Basin, Croatia

Abstract Round goby Neogobius melanostomus is one of the three invasive Ponto-Caspian gobies found in the Sava River basin in Croatia. It has a negative effect on the native ecosystems due to its high invasive potential that enables its rapid spread upstream in inland watercourses. The objective of this study was to determine the differences in sagittal otolith and scale shape of the frontal and established populations of N. melanostomus in two different habitat types. At two sampling sites in the main course of the Sava (Babina Greda, Slavonski Brod) and in a modified habitat (Sava-Odra canal), 20 individuals of N. melanostomus were collected and analysed. The geometric morphometric method was used together with Procrustes analysis of variance, canonical variate analysis and discriminant function analysis to analyse the otolith and scale shape. Significant differences in both otolith and scale shapes were found between settled (Babina Greda) and frontal (Slavonski Brod) populations from the main course of the Sava River. The main differences were the wider anterior part of the scales and a more pronounced open indentation on the otolith of the Babina Greda population. The settled population in the Sava-Odra canal was significantly different in otolith shape from the Babina Greda population but not from the Slavonski Brod population, suggesting that the upstream migration consisted of individuals with specific phenotype and genotype. Otoliths generally expressed greater shape variability than scales and thus may be more useful for differentiating between closely related populations on a finer scale. The results of this study suggest that the shape of otoliths and scales can be used to distinguish between closely related populations of N. melanostomus from different habitats but more comprehensive studies are needed due to the small number of samples.

Phenotypic Variation of Component Traits Affecting Maturity in Cultivated Peanut (Arachis hypogaea L.)

A wide range of time-to-maturity exists among peanut accessions and cultivars, and it is a complex trait likely controlled by many genes and influenced by the environment. Underground formation of fruit coupled with indeterminate growth habit makes peanut a difficult crop species to explore genetic controls of this trait. Dividing the total phenotype of time-to-maturity into component traits can facilitate the dissection of genetic pathways controlling maturity in peanut. In this study, component traits contributing to time-to-maturity included flowering on the main stem, flowering rate, flower-to-peg conversion ratio, internode length, distribution of reproductive and vegetative nodes, branch numbers, percentage of harvestable pods, and harvest index, which were quantified for six genetically diverse peanut genotypes. Statistically significant differences were detected for all measured traits among the tested genotypes. These genotypes are parental lines of four established recombinant inbred populations. Populations with contrasting parental phenotypic values could be utilized for further QTL mapping of the relevant traits.

Urbanismo de riesgo, el principio de los desastres urbanos y su prevención con sistemas geoinformáticos, CDMX, México

The so-called urbanism of risk created the conditions for the inadequate urban planning in Mexico City (CDMX), which affects the populations established there. This term is little known today and should not be confused with urban risk. Nowadays, the incorrect urban configuration creates awareness in the inhabitants about the risks present in their lives, according to the impact of natural phenomena (hazards). It is important to understand that the effects of disasters in urban areas are derived from growth in places with unsuitable characteristics, due to the irregularity of the terrain. Risk is the result between hazard and vulnerability, which becomes urban risk when it affects the established population. The contribution of this article shows that the beginning of the adequate urban configuration based on geoinformatics systems will prevent risk urbanism in areas where there is no city growth yet. As a result, it is shown the crossing of variables provided by governmental institutions and real events occurred, according to floods, landslides, earthquakes and collapse of mined areas, using geoinformatics systems to show the municipalities with greater affectation, according to the existing urban risk, which can be replicated and attended in other parts of the country and the world, based on the management between government, academics and population, with the objective of preventing the creation of risk urbanism.

Profiles of COVID-19 Impact on Informal Caregivers of Older Mexican Americans.

Objectives: This manuscript is a descriptive exploratory study of the impact of the COVID-19 pandemic for caregivers of very old Mexican Americans. Methods: Using data from Wave 10 of the Hispanic Established Population for the Epidemiological Study of Elderly (2021), we examined the characteristics of caregivers of very old Mexican Americans by their perceived level of impact from the pandemic. We examined sociodemographic characteristics, COVID-19 testing and vaccination, stress and depression, and health of caregivers and care recipients. Results: Caregivers who reported the most impact were more likely to report financial and emotional stress. They reported more depressive symptoms and high levels of distress related to neuropsychological behavior symptoms of their care recipient. Discussion: High levels of depressive symptoms, financial stress, and neuropsychological behavior symptoms illustrate that the concerns of caregivers before the pandemic were heightened during the pandemic.

Intramuscular Immunization with a Liposomal Multi-Epitope Chimeric Protein Induces Strong Cellular Immune Responses against Visceral Leishmaniasis.

Control of the intracellular parasite Leishmania (L.) requires the activation of strong type 1 cellular immune responses. Towards this goal, in the present study, a multiepitope chimeric protein named LiChimera was encapsulated into cationic liposomes and its protective efficacy against experimental visceral leishmaniasis was investigated. Liposomal LiChimera conferred significant protection against L. infantum as evidenced by the significantly reduced parasite loads in the spleen and liver. Protection detected in Lipo:LiChimera-immunized mice was dependent on the differentiation of long-lasting cellular immune responses and particularly the induction of antigen-specific multifunctional memory CD4+ TH1 and CD8+ T cells that persisted during infection, as evidenced by the persistent high production of IFN-γ and IL-2 and proliferation activity. Notably, protected mice were also characterized by significantly low numbers of non-regulatory CD4+ T cells able to co-produce IFN-γ and IL-10, an important population for disease establishment, as compared to non-immunized control group. Collectively, these results demonstrate that cationic liposomes containing LiChimera can be considered an effective candidate vaccine against visceral leishmaniasis.

A latent auction model of firm establishment location choice in the Greater Toronto Area

We present a maximum bid model for business establishments in the Greater Toronto Area (GTA). The model is based on a latent auction approach, wherein price and utility are jointly modeled in a random utility-maximizing framework. Structural relationships between establishments by their industry classification and type (i.e., headquarters, subsidiary, branch, or single location) are explored through a generalized nesting correlation structure. This structure provides a mechanism for differentiating between branch and single-location establishments, having seemingly similar functions, but differing in their allocation between industry and type nests. Maximum bid models are estimated for the full establishment population in the GTA at the level of individual buildings. The model scope allows us to provide a range of insights into establishment location choice behavior, which was previously infeasible due to data limitations. We find that professional service establishments tend to locate near passenger rail stations (i.e., subway and LRT), while industrial establishments tend to locate near major highway interchanges. We confirm the finding by Kenworthy and Laube (1999) that Canadian cities are less auto-dependent than US cities, albeit from the perspective of establishment location rather than individual vehicle travel data.

Rapid Physiological Plasticity in Response to Cold Acclimation for Nonnative Italian Wall Lizards (Podarcis siculus) from New York.

AbstractThermal physiology helps us understand how ectotherms respond to novel environments and how they persist when introduced to new locations. Researchers generally measure thermal physiology traits immediately after animal collection or after a short acclimation period. Because many of these traits are plastic, the conclusions drawn from such research can vary depending on the duration of the acclimation period. In this study, we measured the rate of change and extent to which cold tolerance (critical thermal minimum [CTmin]) of nonnative Italian wall lizards (Podarcis siculus) from Hempstead, New York, changed during a cold acclimation treatment. We also examined how cold acclimation affected heat tolerance (critical thermal maximum [CTmax]), thermal preference (Tpref), evaporative water loss (EWL), resting metabolic rate (RMR), and respiratory exchange ratio (RER). We predicted that CTmin, CTmax, and Tpref would decrease with cold acclimation but that EWL and RMR would increase with cold acclimation. We found that CTmin decreased within 2 wk and that it remained low during the cold acclimation treatment; we suspect that this cold tolerance plasticity reduces risk of exposure to lethal temperatures during winter for lizards that have not yet found suitable refugia. CTmax and Tpref also decreased after cold acclimation, while EWL, RMR, and RER increased after cold acclimation, suggesting trade-offs with cold acclimation in the form of decreased heat tolerance and increased energy demands. Taken together, our findings suggest that cold tolerance plasticity aids the persistence of an established population of invasive lizards. More generally, our findings highlight the importance of accounting for the plasticity of physiological traits when investigating how invasive species respond to novel environments.