Self-Assembly of DNA Graphs and Postman Tours

DNA graph structures can self-assemble from branched junction molecules to yield solutions to computational problems. Self-assembly of graphs have previously been shown to give polynomial time solutions to hard computational problems such as 3-SAT and k-colorability problems. Jonoska et al. have proposed studying self-assembly of graphs topologically, considering the boundary components of their thickened graphs, which allows for reading the solutions to computational problems through reporter strands. We discuss weighting algorithms and consider applications of self-assembly of graphs and the boundary components of their thickened graphs to problems involving minimal weight Eulerian walks such as the Chinese Postman Problem and the Windy Postman Problem

Comparing life histories across taxonomic groups in multiple dimensions: how mammal-like are insects?

Explaining variation in life histories remains a major challenge because they are multi-dimensional and there are many competing explanatory theories and paradigms. An influential concept in life history theory is the ’fast-slow continuum’, exemplified by mammals. Determining the utility of such concepts across taxonomic groups requires comparison of the groups’ life histories in multidimensional space. Insects display enormous species richness and phenotypic diversity, but testing hypotheses like the ’fast-slow continuum’ has been inhibited by incomplete trait data. We use phylogenetic imputation to generate complete datasets of seven life history traits in orthopterans (grasshoppers and crickets) and examine the robustness of these imputations for our findings. Three phylogenetic principal components explain 83-96% of variation in these data. We find consistent evidence of an axis mostly following expectations of a ’fast-slow continuum’, except that ’slow’ species produce larger, not smaller, clutches of eggs. We show that the principal axes of variation in orthopterans and reptiles are mutually explanatory, as are those of mammals and birds. Essentially, trait covariation in Orthoptera, with ’slow’ species producing larger clutches, is more reptile-like than mammal-or-bird-like. We conclude that the ’fast-slow continuum’ is less pronounced in Orthoptera than in birds and mammals, reducing the universal relevance of this pattern, and the theories that predict it

Exploring Equilibria between Aluminium(I) and Aluminium(III):The Formation of Dihydroalanes, Masked Dialumenes and Aluminium(I) Species

The design of new reductive routes to low oxidation state aluminium (Al) compounds offers the opportunity to better understand redox processes at the metal centre and develop reactivity accordingly. Here, a monomeric Al(I) compound acts as a stoichiometric reducing agent towards a series of Al(III) dihydrides, leading to the formation of new low oxidation state species including symmetric and asymmetric dihydrodialanes, and a masked dialumene. These compounds are formed by a series of equilibrium processes involving Al(I), Al(II) and Al(III) species and product formation can be manipulated by fine‐tuning the reaction conditions. The transient formation of monomeric Al(I) compounds is proposed: this is shown to be energetically viable by computational (DFT) investigations and reactivity studies show support for the formation of Al(I) species. Importantly, despite the potential for the equilibrium mixtures to lead to ill‐defined reactivity, controlled reactivity of these low oxidation state species is observed

A real‐world experience with the bioactive human split thickness skin allograft for venous leg ulcers

Data collected from standardized clinical practices can be valuable in evaluating the real‐world therapeutic benefit of skin substitutes in the treatment of venous leg ulcers (VLU). Utilizing such a dataset, this study aimed to validate the effectiveness of a bioactive human split‐thickness skin allograft for the treatment of VLU in the real‐world setting and to understand how certain variables impacted healing rates. From a pool of 1474 VLU treated with allograft, 862 ulcers in 742 patients were selected from a large wound EMR database and analyzed. All patients received standard wound care prior to allograft application. Impact of ulcer duration, number of applications, ulcer size, and time to application were analyzed. The VLU, on average, were of 189 days duration with a mean ulcer size of 19.3 cm2. During treatment, 70.7% of wounds healed, with an average time to closure of 15 weeks (SD = 14.1 weeks). The percentage of VLU less than one‐year duration that healed was significantly higher (72.3%) than the percentage of VLU with duration of greater than 1 years (51.5%) ( χ2 = 18.17; P < .001). Ulcers less than 10 cm2 in size were more likely to heal (73.9%) than those larger than 10 cm2 (67.9%) ( χ2 = 8.65, P = .03). VLU receiving allograft within 90 days of initial presentation are 1.4 times more likely to heal vs those receiving their first BSA application after 90 days of standard of care (95% CI: [1.05, 1.86], P = .02). Allograft used in wound clinics healed a majority of refractory VLU, even in large ulcers of long duration, which are more difficult to heal. Smaller wound, size, and shorter wound duration were associated with greater likelihood of healing. VLUs treated earlier with allograft had better healing outcomes. Clinicians may consider more aggressive and timely treatment with allograft for refractory VLU

Data from: Comparing life histories across taxonomic groups in multiple dimensions: how mammal-like are insects?

Explaining variation in life histories remains a major challenge because they are multi-dimensional and there are many competing explanatory theories and paradigms. An influential concept in life history theory is the 'fast-slow continuum', exemplified by mammals. Determining the utility of such concepts across taxonomic groups requires comparison of the groups' life histories in multidimensional space. Insects display enormous species richness and phenotypic diversity, but testing hypotheses like the 'fast-slow continuum' has been inhibited by incomplete trait data. We use phylogenetic imputation to generate complete datasets of seven life history traits in orthopterans (grasshoppers and crickets) and examine the robustness of these imputations for our findings. Three phylogenetic principal components explain 83-96% of variation in these data. We find consistent evidence of an axis mostly following expectations of a 'fast-slow continuum', except that 'slow' species produce larger, not smaller, clutches of eggs. We show that the principal axes of variation in orthopterans and reptiles are mutually explanatory, as are those of mammals and birds. Essentially, trait covariation in Orthoptera, with 'slow' species producing larger clutches, is more reptile-like than mammal-or-bird-like. We conclude that the 'fast-slow continuum' is less pronounced in Orthoptera than in birds and mammals, reducing the universal relevance of this pattern, and the theories that predict it

Referenced Dataset

Excel file (.xlsx) containing the dataset of Orthopteran life history traits ("Data" tab), and numbered references ("References" tab)

Reptile Dataset

Reptile life history data used in the analyses across taxonomic groups. Collated from: Allen et al., 2017; Myhrvold et al., 2015 [see text]

Mammal Dataset

Mammal life history data used in the analyses across taxonomic groups. Collated from: Capellini et al, 2015; Jeschke and Kokko, 2009; Myhrvold et al., 2015 [see text]

Code: The fast-slow continuum hypothesis in Orthoptera

R code for analyses within Orthoptera, including: PGLS analyses, imputation of missing data (at various levels of completeness), and phylogenetic PCAs

Orthoptera dataset (plain text)

Plain text version of the Orthoptera dataset, used for statistical analyses. The references are listed in the Excel spreadsheet