84 research outputs found
Genetic and genomic approaches to the conservation of the threatened crucian carp Carassius carassius (L.) : phylogeography, hybridisation and introgression
Biological invasions can have dramatic detrimental impacts on ecosystems, however they also represent rich opportunities to study the evolutionary processes associated with them. Hybridisation and subsequent introgression are two such processes and are common among native and non-native species. The crucian carp, Carassius carassius (L.), is a European freshwater fish that is threatened throughout much of its native range by several factors including hybridisation and introgression with three non-native species, the goldfish, Carassius auratus (L.), the gibel carp, Carassius gibelio (Bloch), and the common carp, Cyprinus carpio (L.). The conservation of C. carassius is hampered by a lack of phylogeographic knowledge for the species and no knowledge of the extent or impact of hybridisation and introgression. Contemporary genomic approaches such as Restriction Site Associated DNA sequencing (RADseq) can offer unprecedented insights into such research areas, however RADseq comes with several sources of potential bias. Exploratory analyses in Chapter 2 show that two sources of bias in particular, null alleles and over merged ohnolog loci, are highly important in this dataset, but can be filtered using population genetics statistics. The filtered dataset is used in phylogeographic analyses in Chapter 3, along with microsatellite and mitochondrial DNA and show that C. carassius exists as two major lineages in Europe, which diverged approximately 2.26 million years ago, and should be treated as separate units for conservation. These lineages result from the C. carassius postglacial recolonisation routes thtough Europe, which are highly distinct from the general patterns seen in other freshwater fish species. These phylogeographic results showed high similarity between C. carassius in England and those in continental Europe, calling into question the presently assumed native status of C. carassius in England, which has been contentious in the past. Empirical tests of this status using microsatellites showed that, in fact, C. carassius is most likely introduced in England around the 15th century, raising interesting discussions pertaining to their conservation in the England. Lastly, in Chapter 5, microsatellite and RADseq approaches show that hybridisation between C. carassius and non-native species is prevalent where they are sympatric, however backcrosses are rare, and there is no evidence of further introgression between the species studied. Taken together, these results suggest that postzygotic mechanisms of isolation limit interspecific gene flow, and conservationists should focus further research on the direct impacts of non-native species and F1 hybrids
Factors affecting the dispersal of the invasive ladybirds Coccinella septempunctata and Harmonia axyridis
Biological invasions can have deleterious impacts on native ecosystems, but also offer opportunities for studying evolution. A fundamental question in invasion biology is: what factors are important determining invasion success? Dispersal is essential to the establishment and persistence of populations in heterogeneous environments. This thesis investigated dispersal for its importance in invasions in two ladybirds, Harmonia axyridis (Pallas) and Coccinella septempunctata (L.) (Coleoptera: Coccinellidae). The effects of abiotic and biotic factors on ladybird aerial densities (AD) were investigated using Vertical Looking Radar, a tool which allows for detailed observations of high altitude coccinellid flight for the first time. Temperature was found to be the strongest predictor of AD, wind speed had a negative relationship with AD and aphids had no significant predictive effect. Comparison of H. axyridis distribution and topographical distribution of temperature and wind speed in the U.K. suggests that unfavourable meteorological conditions, for example over the Pennines and Cambrian Mountains, may act as a barrier to dispersal; slowing the spread of the H. axyridis in the U.K. To investigate characteristics of ladybird flight in controlled conditions, a novel in vitro flight test method was designed. This successful method was used to test the hypothesis that increased dispersal ability at range expansion boundaries will be selected for. No significant difference in flight time was found between native and invasive H. axyridis populations. An explanation may be the trade off between dispersal ability and fecundity at range expansion boundaries, which warrants further investigation. The results presented in this thesis add to our understanding of dispersal ability in coccinellids and could be used to help predict future spread of invasive ladybirds. Future work should investigate the potential trade off between dispersal ability and fecundity at range expansion boundaries and whether phenotypic plasticity in dispersal is a predisposition to invasion success
Variation in Mating Dynamics across Five Species of Leiobunine Harvestmen (Arachnida: Opliones)
The study of mating choices often focuses on correlates of traits to the overall outcome of a mating interaction. However, mating interactions can proceed through a series of stages, with opportunities for assessment at each stage. We compared whether male or female size predicted mating interaction outcome across several stages of mating in five species of North American leiobunine harvestmen (commonly known as daddy longlegs). Leiobunine harvestmen have been previously shown to exhibit incredible morphological diversity consistent with a spectrum of male–female antagonism. Across all of the species, we found a general progression of female size predicting the outcome (success and timing) of early stages of interactions, and male size or male size relative to female size predicting the outcome and timing of later stages of interactions. We also found that size was not a strong predictor of outcome in the two species on the lower end of the antagonism spectrum. The variation in how female and male size predicted outcomes across species and stages of mating suggests that multiple mechanisms may operate to shape mating dynamics within and across species. Given the close relatedness of the species studied, the patterns we uncovered suggest a rapid evolution of the traits and processes predicting the outcome of mating interactions
Novel genetic sex markers reveal high frequency of sex reversal in wild populations of the agile frog (Rana dalmatina) associated with anthropogenic land use
A View of Tropical Cyclones from Above: The Tropical Cyclone Intensity Experiment
Tropical cyclone (TC) outflow and its relationship to TC intensity change and structure were investigated in the Office of Naval Research Tropical Cyclone Intensity (TCI) field program during 2015 using dropsondes deployed from the innovative new High-Definition Sounding System (HDSS) and remotely sensed observations from the Hurricane Imaging Radiometer (HIRAD), both on board the NASA WB-57 that flew in the lower stratosphere. Three noteworthy hurricanes were intensively observed with unprecedented horizontal resolution: Joaquin in the Atlantic and Marty and Patricia in the eastern North Pacific. Nearly 800 dropsondes were deployed from the WB-57 flight level of âŒ60,000 ft (âŒ18 km), recording atmospheric conditions from the lower stratosphere to the surface, while HIRAD measured the surface winds in a 50-km-wide swath with a horizontal resolution of 2 km. Dropsonde transects with 4â10-km spacing through the inner cores of Hurricanes Patricia, Joaquin, and Marty depict the large horizontal and vertical gradients in winds and thermodynamic properties. An innovative technique utilizing GPS positions of the HDSS reveals the vortex tilt in detail not possible before. In four TCI flights over Joaquin, systematic measurements of a major hurricaneâs outflow layer were made at high spatial resolution for the first time. Dropsondes deployed at 4-km intervals as the WB-57 flew over the center of Hurricane Patricia reveal in unprecedented detail the inner-core structure and upper-tropospheric outflow associated with this historic hurricane. Analyses and numerical modeling studies are in progress to understand and predict the complex factors that influenced Joaquinâs and Patriciaâs unusual intensity changes
Rural Primary Care Providersâ Experiences and Knowledge Regarding LGBTQ Health in a Midwestern State
PurposeHealth disparities among LGBTQ people have been documented across various settings and recent research has indicated that many disparities are heightened in the context of rurality. Among these disparities is the decreased rate of primary care utilization by rural LGBTQ individuals. Understanding and addressing provider knowledge and attitudes related to LGBTQ health provides a relevant avenue for addressing underutilization.MethodsThe study presented was a mailâout survey regarding rural primary care providersâ knowledge and experiences regarding LGBTQ health. Publicly available records were compiled to recruit a total sample of 113 primary care providers, at a response rate of 19.8%.FindingsA majority of respondents reported experience providing care to LGBTQ patients, while only slightly over half had received LGBTQ health education. Data analyses revealed significant associations between reported experiences and patient characteristics including religion, religiousness, age, length of time practicing in current provider role, and gender identity. Provider knowledge of LGBTQ health varied greatly across the items assessed. Provider profession (physician, nurse practitioner, physician assistant) and length of current county residence were significantly predictive of LGBTQ knowledge scores.ConclusionResults provide insight into rural health care for LGBTQ people. Preeminent findings were: (1) an existing need for LGBTQ health education, (2) variation in knowledge across content areas, and (3) association between knowledge, profession, and length of current county residence. Promotion of rural LGBTQ health may benefit by addressing identified gaps in current care.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/149681/1/jrh12322.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/149681/2/jrh12322_am.pd
Young stars and brown dwarfs surrounding Alnilam (eps Ori) and Mintaka (del Ori)
Aims: We look for new regions for the search of substellar objects. Methods:
Two circular areas, 45 arcmin-radius each, centred on the young massive star
systems Alnilam and Mintaka in the Orion Belt, have been explored. The regions
are very young (less than 10 Ma), have low extinction, and are neighbours to
sigma Orionis (~3 Ma), a young open cluster very rich in brown dwarfs and
planetary-mass objects. We have used Virtual Observatory tools, the
astro-photometric Tycho-2, DENIS and 2MASS catalogues, 10 control fields at
similar galactic latitudes, and X-ray, mid-infrared and spectroscopic data from
the literature. Results: We have compiled exhaustive lists of known young stars
and new candidate members in the Ori OB1b association, and of fore- and
background sources. A total of 136 stars display features of extreme youth,
like early spectral types, lithium in absorption, or mid-infrared flux excess.
Other two young brown dwarf and 289 star candidates have been identified from
an optical/near-infrared colour-magnitude diagram. We list additional 74 known
objects that might belong to the association. This catalogue can serve as an
input for characterisation of the stellar and high-mass substellar populations
in the Orion Belt. Finally, we have investigated the surface densities and
radial distributions of young objects surrounding Alnilam and Mintaka, and
compared them with those in the sigma Orionis cluster. We report a new open
cluster centred on Mintaka. Conclusions: Both regions can be analogs to the
sigma Orionis cluster, but more massive, more extended, slightly older, and
less radially concentrated.Comment: Accepted for publication in A&A. It will be published on line in
Sect. 14 (Catalogs and data). Tables in Appendix A will soon be available at
the CD
Reading and Ownership
First paragraph: âIt is as easy to make sweeping statements about reading tastes as to indict a nation, and as pointless.â This jocular remark by a librarian made in the Times in 1952 sums up the dangers and difficulties of writing the history of reading. As a field of study in the humanities it is still in its infancy and encompasses a range of different methodologies and theoretical approaches. Historians of reading are not solely interested in what people read, but also turn their attention to the why, where and how of the reading experience. Reading can be solitary, silent, secret, surreptitious; it can be oral, educative, enforced, or assertive of a collective identity. For what purposes are individuals reading? How do they actually use books and other textual material? What are the physical environments and spaces of reading? What social, educational, technological, commercial, legal, or ideological contexts underpin reading practices? Finding answers to these questions is compounded by the difficulty of locating and interpreting evidence. As Mary Hammond points out, âmost reading acts in history remain unrecorded, unmarked or forgottenâ. Available sources are wide but inchoate: diaries, letters and autobiographies; personal and oral testimonies; marginalia; and records of societies and reading groups all lend themselves more to the case-study approach than the historical survey. Statistics offer analysable data but have the effect of producing identikits rather than actual human beings. The twenty-first century affords further possibilities, and challenges, with its traces of digital reader activity, but the map is ever-changing
Schoolbooks and textbook publishing.
In this chapter the author looks at the history of schoolbooks and textbook publishing. The nineteenth century saw a rise in the school book market in Britain due to the rise of formal schooling and public examinations. Although the 1870 Education and 1872 (Scotland) Education Acts made elementary education compulsory for childern between 5-13 years old, it was not until the end of the First World War that some sort form of secondary education became compulsory for all children
Evaluating the Effects of SARS-CoV-2 Spike Mutation D614G on Transmissibility and Pathogenicity.
Global dispersal and increasing frequency of the SARS-CoV-2 spike protein variant D614G are suggestive of a selective advantage but may also be due to a random founder effect. We investigate the hypothesis for positive selection of spike D614G in the United Kingdom using more than 25,000 whole genome SARS-CoV-2 sequences. Despite the availability of a large dataset, well represented by both spike 614 variants, not all approaches showed a conclusive signal of positive selection. Population genetic analysis indicates that 614G increases in frequency relative to 614D in a manner consistent with a selective advantage. We do not find any indication that patients infected with the spike 614G variant have higher COVID-19 mortality or clinical severity, but 614G is associated with higher viral load and younger age of patients. Significant differences in growth and size of 614G phylogenetic clusters indicate a need for continued study of this variant
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