The Two Ring Test: The Unbearable Predictability of Artificial Intelligence

This is a coming-of-age of story of a child born and raised in a post-AI society.

The Persistence of Staphylococcus aureus in Pressure Ulcers: A Colonising Role

Decubitus pressure ulcers (PU) are a major complication of immobilised patients. Staphylococcus aureus is one of the most frequently detected microorganisms in PU samples; however, its persistence and role in the evolution of these wounds is unknown. In this study, we analysed S. aureus strains isolated from PU biopsies at inclusion and day 28. Eleven S. aureus (21.1%) were detected in 52 patients at inclusion. Only six PUs (11.5%) continued to harbour this bacterium at day 28. Using a whole genome sequencing approach (Miseq®, Illumina), we confirmed that these six S. aureus samples isolated at D28 were the same strain as that isolated at inclusion, with less than 83 bp difference. Phenotypical studies evaluating the growth profiles (Infinite M Mano, Tecan®) and biofilm formation (Biofilm Ring Test®) did not detect any significant difference in the fitness of the pairs of S. aureus. However, using the Caenorhabditis elegans killing assay, a clear decrease of virulence was observed between strains isolated at D28 compared with those isolated at inclusion, regardless of the clinical evolution of the PU. Moreover, all strains at inclusion were less virulent than a control S. aureus strain, i.e., NSA739. An analysis of polymicrobial communities of PU (by metabarcoding approach), in which S. aureus persisted, demonstrated no impact of Staphylococcus genus on PU evolution. Our study suggested that S. aureus presented a colonising profile on PU with no influence on wound evolution.

Put to the Test: The Folk-­Tale Motif of the "Test to Prove Worthiness" in Three of Shakespeare's Comedies

<p>Critics have recognised folk‐tales as being among the varied sources Shakespeare has mined for the plots of his plays. However, this recognition has often formed the basis of an argument which seeks to excuse what are perceived as flaws in Shakespeare’s plays, for example claiming that humanised characters jostle against their folk‐tale or popular culture archetypes, or that friction is generated when a folk‐tale plot is placed into a realistic setting. There has been little examination of Shakespeare’s relationship to his sources from folk‐tale, and so in this thesis I use the motif of the “test imposed to prove worthiness” (Stith Thompson’s Motif H900) as an example of the way Shakespeare develops, doubles and ultimately subverts these sources. I examine three comedies which employ this motif: The Taming of the Shrew, The Merchant of Venice and All’s Well That Ends Well. In the first play I argue that the testing of Katherina’s obedience rebounds to test Petruccio’s masculinity. In The Merchant, I argue that the casket test and doubled ring test play a crucial role in the development of Bassanio’s worthiness and loyalty, simultaneously casting doubt on Portia’s faithfulness. Finally, in relation to All’s Well, I argue that the test motif and by extension its folk‐tale sources are subverted so that the impossible tasks rebound not only on Bertram, but on the play as a whole, testing the genres of romance and realism. I find that testing cycles have a structural function as they fall between the couples’ weddings and consummations. Because of this placement, they are linked to private and public anxieties about sexuality and fidelity, in turn demonstrating their thematic function. The development, doubling and subversion of folk‐tales allow Shakespeare to explore ideas fully, often contrapuntally. Thus, my thesis seeks to address the gap in the critical studies by contending that Shakespeare makes innovative use of his folk‐tale sources. While ambiguity is certainly generated in each of the three plays, this is a deliberate effect rather than a flaw; no apology is required.</p>

Put to the Test: The Folk-­Tale Motif of the "Test to Prove Worthiness" in Three of Shakespeare's Comedies

<p>Critics have recognised folk‐tales as being among the varied sources Shakespeare has mined for the plots of his plays. However, this recognition has often formed the basis of an argument which seeks to excuse what are perceived as flaws in Shakespeare’s plays, for example claiming that humanised characters jostle against their folk‐tale or popular culture archetypes, or that friction is generated when a folk‐tale plot is placed into a realistic setting. There has been little examination of Shakespeare’s relationship to his sources from folk‐tale, and so in this thesis I use the motif of the “test imposed to prove worthiness” (Stith Thompson’s Motif H900) as an example of the way Shakespeare develops, doubles and ultimately subverts these sources. I examine three comedies which employ this motif: The Taming of the Shrew, The Merchant of Venice and All’s Well That Ends Well. In the first play I argue that the testing of Katherina’s obedience rebounds to test Petruccio’s masculinity. In The Merchant, I argue that the casket test and doubled ring test play a crucial role in the development of Bassanio’s worthiness and loyalty, simultaneously casting doubt on Portia’s faithfulness. Finally, in relation to All’s Well, I argue that the test motif and by extension its folk‐tale sources are subverted so that the impossible tasks rebound not only on Bertram, but on the play as a whole, testing the genres of romance and realism. I find that testing cycles have a structural function as they fall between the couples’ weddings and consummations. Because of this placement, they are linked to private and public anxieties about sexuality and fidelity, in turn demonstrating their thematic function. The development, doubling and subversion of folk‐tales allow Shakespeare to explore ideas fully, often contrapuntally. Thus, my thesis seeks to address the gap in the critical studies by contending that Shakespeare makes innovative use of his folk‐tale sources. While ambiguity is certainly generated in each of the three plays, this is a deliberate effect rather than a flaw; no apology is required.</p>

Biofilm Formation in Methicillin-Resistant Staphylococcus aureus Isolated in Cystic Fibrosis Patients Is Strain-Dependent and Differentially Influenced by Antibiotics

Cystic fibrosis (CF) is a genetic disease with lung abnormalities making patients particularly predisposed to pulmonary infections. Staphylococcus aureus is the most frequently identified pathogen, and multidrug-resistant strains (MRSA, methicillin-resistant S. aureus) have been associated with more severe lung dysfunction leading to eradication recommendations. Diverse bacterial traits and adaptive skills, including biofilm formation, may, however, make antimicrobial therapy challenging. In this context, we compared the ability of a collection of genotyped MRSA isolates from CF patients to form biofilm with and without antibiotics (ceftaroline, ceftobiprole, linezolid, trimethoprim, and rifampicin). Our study used standardized approaches not previously applied to CF MRSA, the BioFilm Ring test® (BRT®), the Antibiofilmogram®, and the BioFlux™ 200 system which were adapted for use with the artificial sputum medium (ASM) mimicking conditions more relevant to the CF lung. We included 63 strains of 10 multilocus sequence types (STs) isolated from 35 CF patients, 16 of whom had chronic colonization. The BRT® showed that 27% of the strains isolated in 37% of the patients were strong biofilm producers. The Antibiofilmogram® performed on these strains showed that broad-spectrum cephalosporins had the lowest minimum biofilm inhibitory concentrations (bMIC) on a majority of strains. A focus on four chronically colonized patients with inclusion of successively isolated strains showed that ceftaroline, ceftobiprole, and/or linezolid bMICs may remain below the resistance thresholds over time. Studying the dynamics of biofilm formation by strains isolated 3years apart in one of these patients using BioFlux™ 200 showed that inhibition of biofilm formation was observed for up to 36h of exposure to bMIC and ceftaroline and ceftobiprole had a significantly greater effect than linezolid. This study has brought new insights into the behavior of CF MRSA which has been little studied for its ability to form biofilm. Biofilm formation is a common characteristic of prevalent MRSA clones in CF. Early biofilm formation was strain-dependent, even within a sample, and not only observed during chronic colonization. Ceftaroline and ceftobiprole showed a remarkable activity with a long-lasting inhibitory effect on biofilm formation and a conserved activity on certain strains adapted to the CF lung environment after years of colonization.

Hydration dynamics gives the distinctive brown color in the "brown ring" nitrate test

The chemistry of the brown-ring test has been investigated for nearly a century. Though recent studies have focused on solid state structure determination and the measurement of spectra, mechanistic details and kinetics, the aspects of solution structure and dynamics remain unknown. From ab initio molecular dynamics simulations of the brown-ring complex in aqueous solution, we have identified that the classically established pseudo-octahedral [Fe(H2O)5(NO)]2+ complex is in equilibrium with a square-pyramidal [Fe(H2O)4(NO)]2+ complex through the exchange of one of the coordinated H2O molecules. We also find, using ab-initio multi-reference methods, that the mixture of these two complexes is what gives the distinctive brown coloration to the brown-ring test. We show that its UV-vis spectrum can be theoretically reproduced only by accounting these two species and not the [Fe(H2O)5(NO)]2+ complex alone. The energetics of the two complexes are also investigated with multi-reference methods.

Hydration dynamics gives the distinctive brown color in the "brown ring" nitrate test

The brown ring test is one of the most popular and visually appealing reagent tests, commonly known to chemistry undergrads and familiar even to school students. The exact composition, mechanism and structure of the complex has been investigated for nearly a century. Recent studies have elucidated its UV-vis, EPR and Mossbauer spectra, mechanistic details and kinetics, followed by crystallization and structure determination in solid state. Nonetheless these studies were unable to address the aspects of solution structure and dynamics of the brown ring complex. We have conducted ab initio molecular dynamics simulations of the classic brown ring complex in aqueous solution. In the process from the simulation trajectory, we have identified that the classically established pseudo-octahedral [Fe(H2O)5(NO)]2+ complex is in chemical equilibrium with the square-pyramidal [Fe(H2O)4(NO)]2+ complex through the exchange of one of the coordinated H2O molecules. The dynamics in aqueous solution between the penta-aqua and tetra-aqua complexes in the brown ring system has to our knowledge never been suggested earlier. Interestingly we find, using ab initio multi-reference quantum chemical methods i.e. CASSCF/NEVPT2 and CASPT2 calculations, that the mixture of these two complexes is what gives the distinctive brown coloration to the brown ring test. We show that its UV-vis spectrum can be theoretically reproduced only by accounting these two species, and not solely the classically established [Fe(H2O)5(NO)]2+ complex. The energetics of the penta-aqua and tetra-aqua complexes is also investigated at the level of multi-reference quantum chemical methods.