A perturbation approach to coherent propagation of energetic charged particles in random magnetic fields

The Fokker-Planck equation describing the propagation of charged particles in magnetic fields that consist of a dominant constant guiding field and superposed random fluctuations is solved by applying the perturbation method of dividing the total particle density into an averaged isotropic and a small anisotropic component. A particle transport equation is derived which describes the 'coherent' propagation of a particle pulse whose center moves at half the constant total particle velocity in either the positive or negative direction. The range of validity of the coherent solution is examined, and the general formulas for coherent propagation are applied to the slab, isotropic, and Alfven-wave models of magnetic-field fluctuations. Ranges of magnetic-fluctuation spectral indices are identified over which diffusive and coherent particle-transport modes can exist in the three models considered

Cultural factors that affected the spatial and temporal epidemiology of kuru

Kuru is a prion disease which became epidemic among the Fore and surrounding linguistic groups in Papua New Guinea, peaking in the late 1950s. It was transmitted during the transumption (endocannibalism) of dead family members at mortuary feasts. In this study, we aimed to explain the historical spread and the changing epidemiological patterns of kuru by analysing factors that affected its transmission. We also examined what cultural group principally determined a family’s behaviour during mortuary rituals. Our investigations showed that differences in mortuary practices were responsible for the initial pattern of the spread of kuru and the ultimate shape of the epidemic, and for subsequent spatio-temporal differences in the epidemiology of kuru. Before transumption stopped altogether, the South Fore continued to eat the bodies of those who had died of kuru, whereas other linguistic groups, sooner or later, stopped doing so. The linguistic group was the primary cultural group that determined behaviour but at linguistic boundaries the neighbouring group’s cultural practices were often adopted. The epidemiological changes were not explained by genetic differences, but genetic studies led to an understanding of genetic susceptibility to kuru and the selection pressure imposed by kuru, and provided new insights into human history and evolution

Marooned plants : vernacular naming practices in the Mascarene Islands

This article explores possible histories of plant exchanges and plant naming tied to the slave trade between East Africa, Madagascar and the Mascarene Islands. The subsequent 'marronnage' of slaves on these islands - their escape from captivity, sometimes to live in mountain hideouts - continues to inspire cultural references. Inspired by the use of the adjective 'marron/marronne' for a number of plants on Reunion Island, we compile evidence of plant exchanges and plant naming from ecological records, historical accounts and the use of descriptive, emotive or symbolic vernacular names as clues for deepening our knowledge of historical societies and environments. The evidence from the Mascarenes opens a window into the role of the African diaspora in plant introduction, diffusion, domestication and cultivation. We document that maroons relied on a variety of wild, escaped and cultivated plants for their subsistence. We also highlight the role of marronnage in the popular and literary imaginary, with the result that many plants are named 'marron/marrone' in a metaphorical sense. Finally, we identify a few plants that may have been transported, cultivated, or encouraged in one way or another by maroons. Along the way, we reflect on the pitfalls and opportunities of such interdisciplinary work

Visible Light Mediated Aryl Migration by Homolytic C−N Cleavage of Aryl Amines

The photocatalytic preparation of aminoalkylated heteroarenes from haloalkylamides via a 1,4‐aryl migration from nitrogen to carbon, conceptually analogous to a radical Smiles rearrangement, is reported. This method enables the substitution of amino groups in heteroaromatic compounds with aminoalkyl motifs under mild, iridium(III)‐mediated photoredox conditions. It provides rapid access to thienoazepinone, a pharmacophore present in multiple drug candidates for potential treatment of different conditions, including inflammation and psychotic disorders.Aminoalkylated heteroarenes are synthesized by a radical Smiles rearrangement of haloalkylamides through a key C−N cleavage under mild, iridium(III)‐mediated photoredox conditions. The method provides rapid access to the pharmaceutically relevant thienoazepinone scaffold.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/146419/1/anie201806659_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/146419/2/anie201806659.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/146419/3/anie201806659-sup-0001-misc_information.pd

Geometric reconstruction methods for electron tomography

Electron tomography is becoming an increasingly important tool in materials science for studying the three-dimensional morphologies and chemical compositions of nanostructures. The image quality obtained by many current algorithms is seriously affected by the problems of missing wedge artefacts and nonlinear projection intensities due to diffraction effects. The former refers to the fact that data cannot be acquired over the full $180^\circ$ tilt range; the latter implies that for some orientations, crystalline structures can show strong contrast changes. To overcome these problems we introduce and discuss several algorithms from the mathematical fields of geometric and discrete tomography. The algorithms incorporate geometric prior knowledge (mainly convexity and homogeneity), which also in principle considerably reduces the number of tilt angles required. Results are discussed for the reconstruction of an InAs nanowire

Respiratory medicine and thoracic surgery

The document attached has been archived with permission from the editor of the Medical Journal of Australia. An external link to the publisher’s copy is included.John H Alpers, Josephine M Cranston and Alan J Crocket

PFHydro: A New Watershed-Scale Model for Post-Fire Runoff Simulation

Runoff increases after wildfires that burn vegetation and create a condition of soil-water repellence (SWR). A new post-fire watershed hydrological model, PFHydro, was created to explicitly simulate vegetation interception and SWR effects for four burn severity categories: high, medium, low severity and unburned. The model was applied to simulate post-fire runoff from the Upper Cache Creek Watershed in California, USA. Nash–Sutcliffe modeling efficiency (NSE) was used to assess model performance. The NSE was 0.80 and 0.88 for pre-fire water years (WY) 2000 and 2015, respectively. NSE was 0.88 and 0.93 for WYs 2016 (first year post-fire) and 2017 respectively. The simulated percentage of surface runoff in total runoff of WY 2016 was about six times that of pre-fire WY 2000 and three times that of WY 2015. The modeling results suggest that SWR is an important factor for post-fire runoff generation. The model was successful at simulating SWR behavior

The cyclin kinase inhibitor p21CIP1/WAF1 limits glomerular epithelial cell proliferation in experimental glomerulonephritis

The cyclin kinase inhibitor p21CIP1/WAF1 limits glomerular epithelial cell proliferation in experimental glomerulonephritis.BackgroundDuring glomerulogenesis, visceral glomerular epithelial cells (VECs) exit the cell cycle and become terminally differentiated and quiescent. In contrast to other resident glomerular cells, VECs undergo little if any proliferation in response to injury. However, the mechanisms for this remain unclear. Cell proliferation is controlled by cell-cycle regulatory proteins where the cyclin-dependent kinase inhibitor p21Cip1,WAF1 (p21) inhibits cell proliferation and is required for differentiation of many nonrenal cell types.MethodsTo test the hypothesis that p21 is required to maintain a differentiated and quiescent VEC phenotype, experimental glomerulonephritis was induced in p21 knockout (-/-) and p21 wild-type (+/+) mice with antiglomerular antibody. DNA synthesis (proliferating cell nuclear antigen, bromodeoxyuridine staining), VEC proliferation (multilayers of cells in Bowman's space), matrix accumulation (periodic acid-Schiff, silver staining), apoptosis (TUNEL), and renal function (serum urea nitrogen) were studied on days 5 and 14 (N = 6 per time point). VECs were identified by location, morphology, ezrin staining, and electron microscopy. VEC differentiation was measured by staining for Wilms’ tumor-1 gene.ResultsKidneys from unmanipulated p21-/- mice were histologically normal and did not have increased DNA synthesis, suggesting that p21 was not required for the induction of VEC terminal differentiation. Proliferating cell nuclear antigen and bromodeoxyuridine staining was increased 4.3- and 3.3-fold, respectively, in p21-/- mice with glomerulonephritis (P < 0.0001 vs. p21+/+ mice). At each time point, VEC proliferation was also increased in nephritic p21-/- mice (P < 0.0001 vs. p21+/+ mice). VEC re-entry into the cell cycle was associated with the loss of Wilms’ tumor-1 gene staining. Nephritic p21-/- mice had increased extracellular matrix protein accumulation and apoptosis and decreased renal function (serum urea nitrogen) compared with p21+/+ mice (P < 0.001).ConclusionThese results show that the cyclin kinase inhibitor p21 is not required by VECs to attain a terminally differentiated VEC phenotype. However, the loss of p21, in disease states, is associated with VEC re-entry into the cell cycle and the development of a dedifferentiated proliferative phenotype