Coordination chemistry of a calix[4]arene-based NHC ligand : dinuclear complexes and comparison to IiPr2Me2

The preparation and coordination chemistry of 5,17-bis(3-methyl-1-imidazol-2-ylidene)-25,26,27,28-tetrapropoxycalix[4]arene (1) is described. Starting from the bis(imidazolium) pro-ligand 1·2HI, the free carbene 1 was readily generated in solution through deprotonation using K[OtBu] and its reactivity with rhodium(I) dimers [Rh(COD)Cl]2 (COD = 1,5-cyclooctadiene) and [Rh(CO)2Cl]2 investigated. Dinuclear complexes were isolated in both cases, where the calix[4]arene-based NHC ligand adopts a bridging μ2-coordination mode, and in one case characterised in the solid-state by X-ray diffraction. Using instead an isolated and well-defined (mononuclear) silver transfer agent, generated by reaction of 1·2HI with Ag2O in the presence of a halide extractor, reactions with [Rh(COD)Cl]2 and [Rh(CO)2Cl]2 produced cationic dinuclear complexes bearing μ2-1 and μ2-Cl bridging ligands. The structural formulation of the novel dinuclear adducts of 1 was aided through spectroscopic congruence with model complexes, containing monodentate 1,3-diisopropyl-4,5-dimethylimidazol-2-ylidene (IiPr2Me2)

Potassium binding adjacent to cationic transition metal fragments: unusual heterobimetallic adducts of a calix[4]arene-based thione ligand

The synthesis of cationic rhodium and iridium complexes of a bis(imidazol-2-thione) functionalised calix[4]arene ligand and their surprising capacity for potassium binding is described. In both cases uptake of the alkali metal into the calix[4]arene cavity occurs despite adverse electrostatic interactions associated with close proximity to the transition metal fragment (Rh+∙∙∙K+ = 3.715(1) Å, Ir+∙∙∙K+ = 3.690(1) Å). The formation and constituent bonding of these unusual heterobimetallic adducts has been interrogated through extensive solution and solid-state characterisation, examination of the host-guest chemistry of the ligand and its upper-rim unfunctionalised calix[4]arene analogue, and computationally using DFT-based energy decomposition analysis (EDA)

Acute Fulminant Colitis Caused by Idiopathic Mesenteric Inflammatory Veno-Occlusive Disease

Mesenteric inflammatory veno-occlusive disease (MIVOD) is an uncommon but important cause of bowel inflammation. MIVOD is characterised by lymphocytic inflammation and non-thrombotic occlusion of the mesenteric venules and veins. We present the case of a young man who presented with acute fulminant colitis, requiring colectomy. The differential diagnosis, pathogenesis and treatment are discussed. This case illustrates the rapid progression from ‘well’ to ‘colectomy’ that can occur with MIVOD. MIVOD should be considered in the differential diagnosis of colitis that does not respond to conventional medical treatment

A bear’s biography: hybrid warfare and the more-than-human battlespace

This paper makes an intervention highlighting the animal dimension of military geographies as an overlooked yet illuminating aspect of the hybrid nature of warfare. By bringing animal geographies into dialogue with critical military geographies and with a focus on relational ethics, the processes, performance and consequences of the more-than-human nature of the battlespace are examined through a vignette of Wojtek the bear. Wojtek was a mascot, pet and officially enlisted soldier of the Polish Army in the Second World War who travelled the desert plains, helped to fight at the Battle of Monte Cassino, before being demobbed with his fellow Polish comrades in the UK, eventually ending his civilian days in Edinburgh Zoo. Although a well-known figure Wojtek and his biography have predominately been used as a means to explore the Polish soldiers’ experience of the Second World War with the result that the bear as an animal is absent. This paper, therefore, puts the bear back into his biography in order to acknowledge the role and lived experience of animals in the military. Further, it suggests that exploring the place of animals in the military requires geographers to articulate the hybrid nature of warfare and also to explore the ethico-political relations this produces

The understated turn: Emerging interests and themes in Canadian posthumanist geography

This is the final version. Available on open access from Wiley via the DOI in this recordPosthumanist geography is a broad tradition incorporating a range of intersecting theoretical approaches including assemblage theory, actor‐network theory, new materialisms, affect theory, neo‐vitalism, political ecology, post‐phenomenology, and non‐representational theory—as well as contributions from a number of theoretically progressive subject fields such as new mobilities, relational thinking, sensory and performance studies, biosocial and biopolitics studies, and science and technology studies. The specificities of and differences between these traditions and fields aside, common to posthumanism is a scepticism of human exceptionalism. Here, the sovereign human subject is decentred, and in doing so, posthumanist work acknowledges the agencies of a full array of human and non‐human actors and forces. Recognizing that there are important “geographies to (the discipline of) geography,” this paper identifies and reviews some of the key posthumanist interests and themes that have emerged over recent years quietly and organically in Canadian geography, namely posthumanist (i) Indigenous geographies; (ii) animal and natures geographies; (iii) health, wellbeing, and disability geographies; (iv) affective and atmospheric geographies; and (v) non‐representational and creative methodologies. The paper concludes with some thoughts on the nature and strengths of Canadian posthumanist geography, and on some possibilities for future advancement

The Chemical Distribution in a Subluminous Type Ia Supernova: HST Images of the SN 1885 Remnant

We present HST images of the remnant of SN 1885 seen in absorption against M31's bulge via resonance lines of Ca I, Ca II, Fe I, and Fe II. Viewed in CaII H & K line absorption, the remnant appears as a nearly black circular spot with an outermost angular radius of 0.40" +/- 0.025" implying r = 1.52 pc and a 120 yr average expansion velocity of 12400 +/-1400 km/s. The strongest Ca II absorption is organized in a broken ring structure with a radius of 0.20" (=6000 km/s) with several apparent absorption `clumps' of an angular size near the pixel scale of 0.05" (= 1500 km/s). The detection of Ca II clumps is the first direct evidence for some instabilities and the existence of a deflagration phase in SNe Ia or, alternatively, mixing induced by radioactive decay of 56^Ni over time scales of seconds or days. However, the degree of mixing allowed by the observed images is much smaller than current 3D calculations for Rayleigh-Taylor dominated deflagration fronts. The images also require a central region of no or little Ca but iron group elements indicative of burning under sufficiently high densities for electron capture taking place, i.e., burning prior to a significant pre-expansion of the WD.Comment: 18 pages, 14 figures. Accepted for publication in Ap

A vision for incorporating human mobility in the study of human-wildlife interactions

As human activities increasingly shape land- and seascapes, understanding human-wildlife interactions is imperative for preserving biodiversity. Habitats are impacted not only by static modifications, such as roads, buildings and other infrastructure, but also by the dynamic movement of people and their vehicles occurring over shorter time scales. While there is increasing realization that both components of human activity significantly affect wildlife, capturing more dynamic processes in ecological studies has proved challenging. Here, we propose a novel conceptual framework for developing a ‘Dynamic Human Footprint’ that explicitly incorporates human mobility, providing a key link between anthropogenic stressors and ecological impacts across spatiotemporal scales. Specifically, the Dynamic Human Footprint integrates a range of metrics to fully acknowledge the time-varying nature of human activities and to enable scale-appropriate assessments of their impacts on wildlife behavior, demography, and distributions. We review existing terrestrial and marine human mobility data products and provide a roadmap for how these could be integrated and extended to enable more comprehensive analyses of human impacts on biodiversity in the Anthropocene

Cheeky Witnessing

Feminists witness legal worlds as they observe, document, and share nothing less than the reproduction of life itself. The world of the abortion trail, where people and things move across borders to change life’s reproduction, has generated a rich plurality of feminist witnessing. In observing how feminist activists improvise with sources, figures and objects of legal consciousness on the abortion trail, this paper seeks to contribute to critical understanding of that plurality, particularly as it emerges in diaspora space. Focusing on Murphy’s concept of immodest witnessing, with its attention to bodies, protocols and apparatuses as constituents of knowledge, the paper thinks with the diasporic feminist activist performance group, Speaking of I.M.E.L.D.A., about how they used self-examination, collective collaboration, and knowledge-sharing on the trail to repeal of Ireland’s Eighth Amendment. The paper argues that their improvisation with legal consciousness of reproductive choice enacts ‘cheeky witnessing’. Cheeky witnessing has three dynamics as a method of observation. First, it is messy and irreverent in innovating with names to display the mixed genealogies of sources of feminist knowledge. Second, cheeky witnessing generates novel subject-figures, such as migrant cleaners, who make knowing connections between different reproductive labourers as observers of the trail in diaspora space. Third, cheeky witnessing places funny objects, knickers in this instance, so as to join up particular public locations and make them more, if unevenly, comfortable for sexual and reproductive bodies. Cheeky witnessing show us how committed and partial practices play a role in speaking across interests and experiences, in stretching the legal imagination, and in sustaining the everyday grind of making a better world

Hints of Universality from Inflection Point Inflation

This work aims to understand how cosmic inflation embeds into larger models of particle physics and string theory. Our work operates within a weakened version of the Landscape paradigm, wherein it is assumed that the set of possible Lagrangians is vast enough to admit the notion of a generic model. By focusing on slow-roll inflation, we examine the roles of both the scalar potential and the space of couplings which determine its precise form. In particular, we focus on the structural properties of the scalar potential, and find a surprising result: inflection point inflation emerges as an important —and under certain assumptions, dominant — possibility in the context of generic scalar potentials. We begin by a systematic coarse graining over the set of possible inflection point inflation models using V.I. Arnold’s ADE classification of singularities. Similar to du Val’s pioneering work on surface singularities, these determine structural classes for inflection point inflation which depened on a distinct number of control parameters. We consider both single and multifield inflation, and show how the various structural classes embed within each other. We also show how such control parameters influence the larger physical models in to which inflation is embedded. These techniques are then applied to both MSSM inflation and KKLT-type models of string cosmology. In the former case, we find that the scale of inflation can be entirely encoded within the super- potential of supersymmetric quantum field theories. We show how this relieves the fine-tuning required in such models by upwards of twelve orders of magnitude. Moreover, unnatural tuning between SUSY breaking and SUSY preserving sectors is eliminated without the explicit need for any hidden sector dynamics. In the later case, we discuss how structural stability vastly generalizes — and addresses — the Kallosh-Linde problem. Implications for the spectrum of SUSY breaking soft terms are then discussed, with an emphasis on how they may assist in constraining the inflationary scalar potential. We then pivot to a general discussion of the FLRW-scalar phase space, and show how inflection points induce caustics — or dynamical fixed points — amongst the space of possible trajectories. These fixed points are then used to argue that for uninformative priors on the space of couplings, the likelihood of inflection point inflation scales with the inverse cube of the number of e-foldings. We point out the geometric origin for the known ambiguity in the Liouville measure, and demonstrate of inflection point inflation ameliorates this problem. Finally we investigate the effect of the fixed point structure on the spectrum of density perturbations. We show how an anomaly in the Cosmic Mircowave Background data — low power at large scales — can be explained as a by product of the fixed point dynamics

Ustekinumab as Induction and Maintenance Therapy for Crohn’s Disease

BACKGROUND Ustekinumab, a monoclonal antibody to the p40 subunit of interleukin-12 and inter-leukin-23, was evaluated as an intravenous induction therapy in two populations with moderately to severely active Crohn’s disease. Ustekinumab was also evaluated as subcutaneous maintenance therapy. METHODS We randomly assigned patients to receive a single intravenous dose of ustekinumab (either 130 mg or approximately 6 mg per kilogram of body weight) or placebo in two induction trials. The UNITI-1 trial included 741 patients who met the criteria for primary or secondary nonresponse to tumor necrosis factor (TNF) antagonists or had unacceptable side effects. The UNITI-2 trial included 628 patients in whom conventional therapy failed or unacceptable side effects occurred. Patients who completed these induction trials then participated in IM-UNITI, in which the 397 patients who had a response to ustekinumab were randomly assigned to receive subcutaneous maintenance injections of 90 mg of ustekinumab (either every 8 weeks or every 12 weeks) or placebo. The primary end point for the induction trials was a clinical response at week 6 (defined as a decrease from baseline in the Crohn’s Disease Activity Index [CDAI] score of ≥100 points or a CDAI score <150). The primary end point for the maintenance trial was remission at week 44 (CDAI score <150). RESULTS The rates of response at week 6 among patients receiving intravenous ustekinumab at a dose of either 130 mg or approximately 6 mg per kilogram were significantly higher than the rates among patients receiving placebo (in UNITI-1, 34.3%, 33.7%, and 21.5%, respectively, with P≤0.003 for both comparisons with placebo; in UNITI-2, 51.7%, 55.5%, and 28.7%, respectively, with P<0.001 for both doses). In the groups receiving maintenance doses of ustekinumab every 8 weeks or every 12 weeks, 53.1% and 48.8%, respectively, were in remission at week 44, as compared with 35.9% of those receiving placebo (P = 0.005 and P = 0.04, respectively). Within each trial, adverse-event rates were similar among treatment groups. CONCLUSIONS Among patients with moderately to severely active Crohn’s disease, those receiving intravenous ustekinumab had a significantly higher rate of response than did those receiving placebo. Subcutaneous ustekinumab maintained remission in patients who had a clinical response to induction therapy. (Funded by Janssen Research and Development; ClinicalTrials.gov numbers, NCT01369329, NCT01369342, and NCT01369355.