Curupira tefeensis III: Occurrence of all-cis-1,4-Polyisoprene

An all-cis-1,4-polyisoprene (3.9%) was isolated from the light petroleum extract of the seeds of Curupira tefeensis (Olacaceae). The structure of the compound was elucidated by IR, ¹H- and ¹³C-NMR-spectroscopy.     

46,XY/46,XY,21q- mosaicism in an infant with neutropenia and properdin deficiency

An infant with neutropenia, properdin deficiency, and a 46,XY/46,XY,21q- mosaicism is described. It is not known whether these two findings are related to the missing 21q material. The propositus is normal in appearance, and has none of the phenotypic features associated with the G-group deletion syndromes.     

The Civic Forest

Industrial growth during the twentieth century, fueled by economies of extraction like coal mining, has produced severe environmental degradation and uniquely dispersed metropolitan areas. Silesia, a region of agglomerated mining towns in Southern Poland, is transitioning to a postextraction economy. Sulfur dioxide emissions and deposits of heavy metals altered the acidity of the land, making farming impossible. Terrain subsidence and slag heaps transformed the topography, forming new valleys and mountains. Over time, surface water bodies appeared, and a new forest grew. The Silesian forests remain a reflection, and also extension, of an extractive and extracted time. As forests often demarcate the boundaries of growth, embody narratives of preservationism, and retain the trauma of industrial processes, the Civic Forest addresses the forests of Silesia as a new “center,” one that is capable through their scale and complexity to confront the current challenges and ambitions of the post-extraction metropolis.     

Is the Kanizsa illusion triggered by the simultaneous contrast mechanism?

Current illusory contour models do not predict the disappearance of the Kanizsa illusion due to specific spatial luminance distributions within the inducers. We suggest that these stimulus conditions are characterized by an insufficient amount of induced brightness. Our model's core assumption is that contour edge detection of the Kanizsa illusion and the simultaneous contrast (brightness induction) effect are triggered by the same mechanism. The simultaneous contrast can immunize the occlusion detection mechanism against spatial and temporal noise. Our model contains physiologically inspired building blocks that detect the oriented contour edges, complete the illusory contours, and enhance them. The model succeeds in predicting the appearance and the disappearance of many different Kanizsa illusion variants.     

Propellants Reactivity Enhancement with Nanothermites

Propellant grains (Vectan A1) were coated with a thin and stable layer (50 μm, 10 wt‐%) of a “green” sulfate‐based nanothermite (Na₂SO₄/Al). This flash composition was used herein as an internal pyrotechnic lighter to accelerate the ignition and the combustion of the propellant. The combustion of the modified propellant, which was tested in one‐end open tubes, propagates four orders of magnitude faster than the one of pristine Vectan A1. This tremendous effect was tuned by varying the proportion of coated Vectan A1 grains from 20 to 100 % in the samples. The percolation threshold is in between 20 and 40 %. Beyond this point, the effect can be improved by increasing the proportion of nanothermite‐coated propellant grains in the charge.