Variation in fine-scale genetic structure and local dispersal patterns between peripheral populations of a South American passerine bird

Indexación: Scopus.The distribution of suitable habitat influences natal and breeding dispersal at small spatial scales, resulting in strong microgeographic genetic structure. Although environmental variation can promote interpopulation differences in dispersal behavior and local spatial patterns, the effects of distinct ecological conditions on within-species variation in dispersal strategies and in fine-scale genetic structure remain poorly understood. We studied local dispersal and fine-scale genetic structure in the thorn-tailed rayadito (Aphrastura spinicauda), a South American bird that breeds along a wide latitudinal gradient. We combine capture-mark-recapture data from eight breeding seasons and molecular genetics to compare two peripheral populations with contrasting environments in Chile: Navarino Island, a continuous and low density habitat, and Fray Jorge National Park, a fragmented, densely populated and more stressful environment. Natal dispersal showed no sex bias in Navarino but was female-biased in the more dense population in Fray Jorge. In the latter, male movements were restricted, and some birds seemed to skip breeding in their first year, suggesting habitat saturation. Breeding dispersal was limited in both populations, with males being more philopatric than females. Spatial genetic autocorrelation analyzes using 13 polymorphic microsatellite loci confirmed the observed dispersal patterns: a fine-scale genetic structure was only detectable for males in Fray Jorge for distances up to 450 m. Furthermore, two-dimensional autocorrelation analyzes and estimates of genetic relatedness indicated that related males tended to be spatially clustered in this population. Our study shows evidence for context-dependent variation in natal dispersal and corresponding local genetic structure in peripheral populations of this bird. It seems likely that the costs of dispersal are higher in the fragmented and higher density environment in Fray Jorge, particularly for males. The observed differences in microgeographic genetic structure for rayaditos might reflect the genetic consequences of population-specific responses to contrasting environmental pressures near the range limits of its distribution.http://onlinelibrary.wiley.com/doi/10.1002/ece3.3342/epd

A posteriori Fehlerschätzer für elektromagnetische Kopplungsprobleme in drei Dimensionen

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At-risk Persons' attitudes toward presymptomatic and prenatal testing of Huntington disease in Michigan

One hundred fifty-five individuals at 50% risk of inheriting Huntington disease (HD) were given a questionnaire surveying their sociodemographic characteris-tics, experience with HD, and attitudes toward presymptomatic and prenatal testing in HD. About two-thirds (63.2%) of the persons indicated they would take a presymptomatic test even if no specific treatment was available. Although one-half (49%) of the respondents stated they would make use of a prenatal test, only 43% of these individuals would decide to terminate a heterozygous fetus. Presym-patomatic test results indicating carrier status would influence some of the respondents' decisions about marriage and childbearing. This strong interest of at-risk persons to make use of both presymptomatic and prenatal diagnosis in HD indicates the need for well-organized testing programs. These programs must be designed to address the genetic, psychosocial, and ethical issues that may arise in the use of this type of genetic test.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/38242/1/1320260207_ftp.pd

Understanding mosquito host choice behaviour: a new and cost-effective method of identifying the sex of human hosts in mosquito blood meals

Background: Mosquito-borne diseases are a global health problem, causing hundreds of thousands of deaths/year. Pathogens are transmitted by mosquitoes taking blood from an infected host and then feeding on a new host. Monitoring mosquito host-choice behaviour can help in many aspects of vector-borne disease control. Currently, it is possible to determine the host species and the individual human host using genotyping to match the blood profile of local inhabitants to the blood-meal found in mosquitoes. Epidemiological models generally assume biting behaviour is random, however, numerous studies have shown that certain individuals are more attractive to mosquitoes than others, due to e.g., genetic makeup and profiles of skin microbiota. Analysing blood-meals and illuminating host choice behaviour will help re-evaluate and optimise disease transmission models. Methods: We describe a new blood-meal assay that identifies the sex of the person a mosquito has bitten. The amelogenin locus (AMEL), a sex marker located on both X and Y chromosomes, was amplified by PCR in DNA extracted from Aedes aegypti and Anopheles coluzzii blood-meals. Results: Our results show that AMEL successfully amplifies up to 36 hours after a blood-meal in 63% of An. coluzzii and 80% of Ae. aegypti blood-meals, revealing the sex of humans that were fed on by individual mosquitoes, which enables further exploration of vector mosquito host preferences. This method was successfully tested in both Anopheles coluzzii and Aedes aegypti, important vectors of malaria and arboviruses, respectively. Conclusions: This method, developed with mosquitoes fed on volunteers, can be applied to field-caught mosquitoes where the host species, the biological sex of the human host and host diversity within blood-meals can be determined. Two important vector species were tested successfully in our laboratory experiments, demonstrating the potential of this technique to improve epidemiological models of vector-borne diseases. This viable and highly cost-effective approach has the capacity to improve our understanding of vector-borne disease transmission, specifically gender differences in exposure and attractiveness to mosquitoes. The data gathered from field-studies using our method will shape new transmission models and aid in the implementation of more effective and targeted vector control strategies by better understanding the drivers of vector-host interactions

Data and Image Transfer Using Mobile Phones to Strengthen Microscopy-Based Diagnostic Services in Low and Middle Income Country Laboratories

Background: The emerging market of mobile phone technology and its use in the health sector is rapidly expanding and connecting even the most remote areas of world. Distributing diagnostic images over the mobile network for knowledge sharing, feedback or quality control is a logical innovation. Objective: To determine the feasibility of using mobile phones for capturing microscopy images and transferring these to a central database for assessment, feedback and educational purposes. Methods: A feasibility study was carried out in Uganda. Images of microscopy samples were taken using a prototype connector that could fix a variety of mobile phones to a microscope. An Information Technology (IT) platform was set up for data transfer from a mobile phone to a website, including feedback by text messaging to the end user. Results: Clear images were captured using mobile phone cameras of 2 megapixels (MP) up to 5MP. Images were sent by mobile Internet to a website where they were visualized and feedback could be provided to the sender by means of text message. Conclusion: The process of capturing microscopy images on mobile phones, relaying them to a central review website and feeding back to the sender is feasible and of potential benefit in resource poor settings. Even though the system needs furthe

Remembering and forgetting the Scottish Highlands: Sir James Mackintosh and the forging of a British imperial identity

This article explores the formation of British imperial identity through a focus on the career of Sir James Mackintosh (1765–1832), a well-known Whig intellectual and imperial careerist who originally hailed from the Highlands of Scotland. Using Mackintosh's unpublished letters and autobiography, the article shows how he imagined and narrated his relationship to the Scottish Highlands from the vantage points of Bombay and London. In contrast to recent historiography that has focused on the translation of Scottish society, culture, and identity in British imperial spaces, this article argues that disidentification from the Highlands of Scotland and the erasure of different peoples, cultures, and textures of life was integral to Mackintosh's configuration of a British imperial identity

Potential of essential fatty acid deficiency with extremely low fat diet in lipoprotein lipase deficiency during pregnancy: A case report

BACKGROUND: Pregnancy in patients with lipoprotein lipase deficiency is associated with high risk of maternal pancreatitis and fetal death. A very low fat diet (< 10% of calories) is the primary treatment modality for the prevention of acute pancreatitis, a rare but potentially serious complication of severe hypertriglyceridemia. Since pregnancy can exacerbate hypertriglyceridemia in the genetic absence of lipoprotein lipase, a further reduction of dietary fat intake to < 1–2% of total caloric intake may be required during the pregnancy, along with the administration of a fibrate. It is uncertain if essential fatty acid deficiency will develop in the mother and fetus with this extremely low fat diet, or whether fibrates will cross the placenta and concentrate in the fetus. CASE PRESENTATION: A 23 year-old gravida 1 woman with primary lipoprotein lipase deficiency was seen at 7 weeks of gestation in the Lipid Clinic for management of severe hypertriglyceridemia that had worsened with pregnancy. While on her habitual fat intake of 10% of total calories, her pregnancy resulted in an exacerbation of the hypertriglyceridemia, which prompted further restriction of fat intake to < 2% of total calories, as well as administration of gemfibrozil at a lower than average dose. The level of gemfibrozil, as the active metabolite, in the venous and arterial fetal cord blood was within the expected therapeutic range for adults. The clinical signs and a biomarker of essential fatty acid deficiency, namely the ratio of 20:3 [n-9] to 20:4 [n-6] fatty acids, were closely monitored throughout her pregnancy. Despite her extremely low fat diet, the levels of essential fatty acids measured in the mother and in the fetal blood immediately postpartum were normal. Normal essential fatty acid levels may have been achieved by the topical application of sunflower oil. CONCLUSIONS: An extremely low fat diet in combination with topical sunflower oil and gemfibrozil administration was safely implemented in pregnancy associated with the severe hypertriglyceridemia of lipoprotein lipase deficiency

‘Orientalism is a partisan book’: applying Edward Said's insights to early modern travel writing

Since its publication in 1978, Edward Said's Orientalism has had a significant impact on postcolonial studies in a range of fields. This paper assesses his impact on the historiography of Anglophone travel writing concerning Ottoman Empire during the early modern period. Said's analysis of the relationship between representational power and colonial authority remains relevant to our understanding of early modern travel texts. Said's epistemology raises significant issues for historians of early modern intercultural encounters. This article summarises recent debates surrounding early modern travel narratives. It contrasts doctrinaire applications of Said's theory with more recent, particularistic studies. It provides a much-needed survey of travel writing historiography that considers the continuing impact of Said's postcolonial thought on the study of early modern travel narratives relating to the Ottoman Middle East. In so doing, it explores the lack of fit between early modern travel narratives and Said's methodology. I explore the methodological problems thrown up by conventional applications of Said's epistemology to precolonial travellers' texts. Based on a wide-ranging survey of Said's oeuvre, the article demonstrates that, more than 30 years on, Said's work remains relevant to the historiographical challenges presented by early modern English travel writing about Islam