scholarly journals Current geography masks dynamic history of gene flow during speciation in northern Australian birds

2017 ◽  
Author(s):  
Joshua V. Peñalba ◽  
Leo Joseph ◽  
Craig Moritz

AbstractDuring early stages of speciation, genome divergence is greatly influenced by gene flow. As populations diverge, geography can allow or restrict gene flow in the form of barriers. Current geography, e.g. whether sister species are allopatric or parapatric, is often used to predict the potential for gene flow during the divergence process. We test the validity of this assumption in eight meliphagoid bird species codistributed across four regions. These regions are separated by known biogeographic barriers within and between northern Australia and Papua New Guinea. We find that bird populations across the same barrier have a range of divergence levels and probability of gene flow regardless of range connectivity. Geographic distance and maximum range connectivity over time can better predict divergence and probability of gene flow than whether populations are currently allopatric or parapatric. We also find support for a nonlinear decrease of the probability of gene flow during the divergence process. This implies that although gene flow influences divergence early in speciation, other factors associated with higher divergence restrict gene flow later in speciation. Current geography may then mislead inferences regarding potential for gene flow during speciation under a complex and dynamic history of geographic and reproductive isolation.

2021 ◽  
Vol 12 ◽  
Author(s):  
Alison G. Nazareno ◽  
L. Lacey Knowles ◽  
Christopher W. Dick ◽  
Lúcia G. Lohmann

Seed dispersal is crucial to gene flow among plant populations. Although the effects of geographic distance and barriers to gene flow are well studied in many systems, it is unclear how seed dispersal mediates gene flow in conjunction with interacting effects of geographic distance and barriers. To test whether distinct seed dispersal modes (i.e., hydrochory, anemochory, and zoochory) have a consistent effect on the level of genetic connectivity (i.e., gene flow) among populations of riverine plant species, we used unlinked single-nucleotide polymorphisms (SNPs) for eight co-distributed plant species sampled across the Rio Branco, a putative biogeographic barrier in the Amazon basin. We found that animal-dispersed plant species exhibited higher levels of genetic diversity and lack of inbreeding as a result of the stronger genetic connectivity than plant species whose seeds are dispersed by water or wind. Interestingly, our results also indicated that the Rio Branco facilitates gene dispersal for all plant species analyzed, irrespective of their mode of dispersal. Even at a small spatial scale, our findings suggest that ecology rather than geography play a key role in shaping the evolutionary history of plants in the Amazon basin. These results may help improve conservation and management policies in Amazonian riparian forests, where degradation and deforestation rates are high.


2019 ◽  
Vol 28 (3) ◽  
pp. 630-643 ◽  
Author(s):  
Joshua V. Peñalba ◽  
Leo Joseph ◽  
Craig Moritz

2020 ◽  
pp. 1-5
Author(s):  
Samira T.Abdulghani ◽  
Samira T.Abdulghani

Background: Congenital anomalies are a major cause of infant morbidity and mortality in developing countries including our country. Registries and data on these anomalies are still primitive and poorly collated. In this study we aimed to assess the important demographic factors associated with the development of congenital anomalies. Methods: This was a cross-sectional hospital-based study involving 880 infants in the 1st year of life registered in the birth defect unit in Fallujah Maternity and Children Hospital in the period between 1st of January 2017 to the 31st of December 2019. The prevalence rate, the pattern of anomalies and the factors associated with their occurrence were determined. Results: The prevalence rate of the group enrolled in this study was 31/1000 total births, congenital heart defects was the commonest followed by central nervous system anomalies, 58% of the infants were males, 65% had ≥ 2.5 kg birth weight & 95% were singletons. Family history of congenital anomalies was found in 31.25% of cases. The largest group of mothers (55.7%) were 21-30 years old & 92.5% of fathers were less than 45 years old. Parental consanguinity reported in 64.3% of the total cases. Only 4.5% of mothers reported history of fever during pregnancy, and none of them had history of exposure to x-ray or teratogenic drug use. Gestational hypertension was reported in 10% of the total (880) mothers, hypertension and diabetes mellitus in 0.3%, while hepatitis C, hepatitis B, toxoplasmosis and epilepsy, each was reported in only one mother (0.1% of the total). Regarding the outcome of pregnancy, 66.6% were live births, 24.2% were abortions and 9.2% were stillbirths. History of previous abortions was reported in 22% of cases. Urban residents accounted for 63% of the families of congenitally abnormal infants while 37% were rural. Conclusion: Congenital anomalies are still a major cause for concern and tension in Fallujah society, there is serious need to establish a surveillance and good statistical system for congenital anomalies and efforts should be made to raise awareness of their occurrence and the associated risk factors in Iraq and other developing countries.


2021 ◽  
Vol 149 ◽  
Author(s):  
Leeberk Raja Inbaraj ◽  
Sindhulina Chandrasingh ◽  
Nalini Arun Kumar ◽  
Jothi Suchitra ◽  
Abi Manesh

Abstract Varicella infection during pregnancy has serious and/or difficult implications and in some cases lethal outcome. Though epidemiological studies in developing countries reveal that a significant proportion of patients may remain susceptible during pregnancy, such an estimate of susceptible women is not known in India. We designed this study to study the prevalence and factors associated with susceptibility to varicella among rural and urban pregnant women in South India. We prospectively recruited 430 pregnant women and analysed their serum varicella IgG antibodies as surrogates for protection. We estimated seroprevalence, the validity of self-reported history of chickenpox and factors associated with varicella susceptibility. We found 23 (95% CI 19.1–27.3) of women were susceptible. Nearly a quarter (22.2%) of the susceptible women had a history of exposure to chickenpox anytime in the past or during the current pregnancy. Self-reported history of varicella had a positive predictive value of 82.4%. Negative history of chickenpox (adjusted prevalence ratio (PR) 1.85, 95% CI 1.15–3.0) and receiving antenatal care from a rural secondary hospital (adjusted PR 4.08, 95% CI 2.1–7.65) were significantly associated with susceptibility. We conclude that high varicella susceptibility rates during pregnancy were noted and self-reported history of varicella may not be a reliable surrogate for protection.


2021 ◽  
Vol 12 ◽  
pp. 215013272110165
Author(s):  
Elaine Seaton Banerjee ◽  
Kyle Shaak ◽  
Nicole Burgess ◽  
Melanie Johnson ◽  
Beth Careyva

Introduction/Objectives: Diabetes and prediabetes impact nearly half of the US adult population and are associated with significant health risks but may be underdiagnosed. Effective screening may improve diagnosis and give patients opportunity to manage their disease. The purpose of this study was to determine screening rates, identify characteristics predictive of screening, and evaluate correct diagnosis of diabetes and prediabetes. Methods: Retrospective chart review of 71 433 patients eligible for diabetes screening, defined by completing A1c test within the 3-year study period. Results: A total of 31.3% of eligible patients received diabetes screening. Factors associated with screening include older age, female sex, non-white race, Hispanic ethnicity, Medicare or Medicaid insurance, higher BMI, and having a medical comorbidity. History of prediabetes or gestational diabetes were the strongest predictors for diabetes screening, but history of gestational diabetes was under-documented. Of those screened, 10.4% had a result consistent with diabetes and 51.8% had a result consistent with prediabetes. However, 52.9% of these patients had a missed diagnosis. Conclusions: Findings of this study indicate the need for uniform coverage for diabetes screening for all insurances, increased documentation of gestational diabetes to improve screening for patients with this history, and improving accurate diagnosis after screening is completed.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Kathryn Wiens ◽  
Laura C. Rosella ◽  
Paul Kurdyak ◽  
Simon Chen ◽  
Tim Aubry ◽  
...  

Abstract Background Healthcare costs are disproportionately incurred by a relatively small group of people often described as high-cost users. Understanding the factors associated with high-cost use of health services among people experiencing homelessness could help guide service planning. Methods Survey data from a general cohort of adults with a history of homelessness and a cohort of homeless adults with mental illness were linked with administrative healthcare records in Ontario, Canada. Total costs were calculated using a validated costing algorithm and categorized based on population cut points for the top 5%, top 6–10%, top 11–50% and bottom 50% of users in Ontario. Multinomial logistic regression was used to identify the predisposing, enabling, and need factors associated with higher healthcare costs (with bottom 50% as the reference). Results Sixteen percent of the general homeless cohort and 30% percent of the cohort with a mental illness were in the top 5% of healthcare users in Ontario. Most healthcare costs for the top 5% of users were attributed to emergency department and inpatient service costs, while the costs from other strata were mostly for physician services, hospital outpatient clinics, and medications. The odds of being within the top 5% of users were higher for people who reported female gender, a regular medical doctor, past year acute service use, poor perceived general health and two or more diagnosed chronic conditions, and were lower for Black participants and other racialized groups. Older age was not consistently associated with higher cost use; the odds of being in the top 5% were highest for 35-to-49-year year age group in the cohort with a mental illness and similar for the 35–49 and ≥ 50-year age groups in the general homeless cohort. Conclusions This study combines survey and administrative data from two cohorts of homeless adults to describe the distribution of healthcare costs and identify factors associated with higher cost use. These findings can inform the development of targeted interventions to improve healthcare delivery and support for people experiencing homelessness.


2021 ◽  
Vol 21 (1) ◽  
pp. 28-52
Author(s):  
Sam Harper ◽  
Ian Waina ◽  
Ambrose Chalarimeri ◽  
Sven Ouzman ◽  
Martin Porr ◽  
...  

This paper explores identity and the recursive impacts of cross-cultural colonial encounters on individuals, cultural materials, and cultural practices in 20th-century northern Australia. We focus on an assemblage of cached metal objects and associated cultural materials that embody both Aboriginal tradition and innovation. These cultural materials were wrapped in paperbark and placed within a ring of stones, a bundling practice also seen in human burials in this region. This ‘cache' is located in close proximity to rockshelters with rich, superimposed Aboriginal rock art compositions. However, the cache shelter has no visible art, despite available wall space. The site shows the utilisation of metal objects as new raw materials that use traditional techniques to manufacture a ground edge metal axe and to sharpen metal rods into spears. We contextualise these objects and their hypothesised owner(s) within narratives of invasion/contact and the ensuing pastoral history of this region. Assemblage theory affords us an appropriate theoretical lens through which to bring people, places, objects, and time into conversation.


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