Modification of intergrain connectivity, upper critical field anisotropy, and critical current density in ion irradiated MgB2 films

We study the effect of 100 MeV Silicon and 200 MeV Gold ion irradiation on the inter and intra grain properties of superconducting thin films of Magnesium Diboride. Substantial decrease in inter-grain connectivity is observed, depending on irradiation dose and type of ions used. We establish that modification of sigma band scattering mechanism, and consequently the upper critical field and anisotropy, depends on the size and directional properties of the extrinsic defects. Post heavy ion irradiation, the upper critical field shows enhancement at a defect density that is five orders of magnitude less compared to neutron irradiation. The critical current density however is best improved through light ion irradiation.Comment: 18 pages, 4 figures, submitte

Improving the use of climate change information for adaption in Uganda

There is little doubt that climate change is already affecting the lives of people in Uganda. Climate change is a particular challenge for the effective management of the country’s water resources. Reliable information on climate change scenarios and impacts is essential to inform policy and practice. While several climate experiments (e.g. CMIP6) are already available, new experiments such as the 4.5 kilometre-scale convection-permitting regional climate simulations for Africa (CP4A) can now be used alongside the CMIP experiments and allow us to assess the impacts of intense storms in more detail than before. However, if these innovative methods are to influence policy, they first need to be well-understood and accessible. This requires capacity strengthening of the professionals and researchers so that they can analyse such experiments. This workshop provided an opportunity for practitioners in Uganda to learn about a range of climate experiments and see results from case studies focussed on water resources, tea production and urban flooding using the CP4A and CMIP experiments. This was a great opportunity particularly for early career staff at the Ministry of Water and Environment, Ministry of Agriculture Animal and Fisheries and Uganda Electricity Generation Company Limited (UEGCL) as well as researchers at Makerere University

Extensive Robertsonian rearrangement: implications for the radiation and biogeography of Planipapillus Reid (Onychophora : Peripatopsidae)

The remarkable diversity in chromosome number within Planipapillus Reid 1996, the most speciose genus of peripatopsid onychophorans, centred in the alpine region of south-eastern Australia is documented. Robertsonian, whole-arm rearrangements account for the twofold range of diploid numbers in Planipapillus. Ooperipatellus Ruhberg 1985, another clade of oviparous onychophorans, shows a very different pattern, with no karyotypic diversity among species from Australia and New Zealand. Rate constancy in chromosomal evolution among peripatopsid genera would indicate an ancient radiation in Planipapillus, with extant species representing relictual survivors of more recent Pleistocene climatic upheavals. Conversely, if the rearrangements in Planipapillus are the result of recent and rapid karyotypic restructuring, the karyotypic and species diversity within the genus may be attributed to recent population fragmentation and isolation resulting from the repeated glaciation and warming cycles of the Pleistocene rather than stemming from a more ancient radiation. Data from other animal groups support a model of accelerated rates of Robertsonian centric fusions concordant with a recent radiation in Planipapillus. Karyotype change may be an important factor in the generation and maintenance of Planipapillus diversity.9 page(s

Fine-scale phylogeographic congruence despite demographic incongruence in two low-mobility saproxylic springtails

Evolutionary trajectories of codistributed taxa with comparable ecological preferences and dispersal abilities may be similarly impacted by historical landscape-level processes. Species' responses to changes in a shared biogeographic landscape may be purely concerted, completely independent, or classified as falling within an intermediate part of the continuum bounded by these two extremes. With sufficient molecular data, temporal contrasts of congruence among taxa with respect to these responses can be made. Such contrasts provide insights into the relative influence of ancient versus more recent climatic (and other) impacts on genetic structuring. Using phylogenetic, allele frequency, and genotypic data from two low-mobility, rotting-log-adapted (saproxylic) springtail species (Collembola) from an isolated 100-km-long section of the Great Dividing Range in southeastern Australia, we tested the concerted-response hypothesis over three timescales. Tests of phylogeographic, demographic, and contemporary population-genetic congruence were performed using an integrative approach that draws on both direct (pattern-based) and indirect (scenario-based) analyses. Our data revealed a general pattern of broad-scale similarities in species' responses to the interaction between Pleistocene climatic cycles and landscape setting, overlaid with some species-specific differences on local geographic and more recent temporal scales. This general pattern of phylogeographic congruence was accompanied by evidence for contemporaneous demographic incongruence indicating that, even at relatively small spatial scales, biogeographic context can exert an overarching influence on genetic structuring