Spatial and temporal variability in floodplain sedimentation during individual hydrologic events on a lowland, meandering river: Allerton Park, Monticello, Illinois

Floodplains are major sinks and sources for sediment within the fluvial system and are constructed through two main processes: lateral and vertical accretion. In fine grained systems, vertical accretion dominates. Overbank flooding and floodplain inundation are dependent on bank height and local topographic variability and this leads to highly variable deposition both spatially and temporally. In order to better understand the dynamics of flooding, single flooding events need to be observed and characterized. Using artificial turf mats as sediment traps, I measured floodplain deposition during five flood events on the floodplain of the Sangamon River at Allerton Park in Monticello, Illinois. The five events observed had peak discharges of 40-250 m3/s. During each event, deposition was found to occur most frequently and with greatest magnitude in and adjacent to floodplain channels. Sediment thicknesses accumulated during each flood event vary from 0-4.5 mm with the largest deposition, equivalent to ~14 mm/year, being observed near a crevasse splay which may be evolving toward a meander cut-off. Flow simulations using the iRIC open source 2-dimensional solver of the St-Venant shallow water equations show how water inundates the floodplain during the rising limb of the largest discharge event observed. Geomorphic features such as floodplain channels, scroll bar topography, and, depressions drastically impact the routing of water over the floodplain and, ultimately, the location and amount of deposition

Multidimensional Characterization and Differentiation of Neurons in the Anteroventral Cochlear Nucleus

Multiple parallel auditory pathways ascend from the cochlear nucleus. It is generally accepted that the origin of these pathways are distinct groups of neurons differing in their anatomical and physiological properties. In extracellular in vivo recordings these neurons are typically classified on the basis of their peri-stimulus time histogram. In the present study we reconsider the question of classification of neurons in the anteroventral cochlear nucleus (AVCN) by taking a wider range of response properties into account. The study aims at a better understanding of the AVCN's functional organization and its significance as the source of different ascending auditory pathways. The analyses were based on 223 neurons recorded in the AVCN of the Mongolian gerbil. The range of analysed parameters encompassed spontaneous activity, frequency coding, sound level coding, as well as temporal coding. In order to categorize the unit sample without any presumptions as to the relevance of certain response parameters, hierarchical cluster analysis and additional principal component analysis were employed which both allow a classification on the basis of a multitude of parameters simultaneously. Even with the presently considered wider range of parameters, high number of neurons and more advanced analytical methods, no clear boundaries emerged which would separate the neurons based on their physiology. At the current resolution of the analysis, we therefore conclude that the AVCN units more likely constitute a multi-dimensional continuum with different physiological characteristics manifested at different poles. However, more complex stimuli could be useful to uncover physiological differences in future studies

The role of 'Autonomy' in teaching expertise

Debates around the effects of ‘new public measures’ emphasise changes to teachers’ practices, role and expertise. While critics lament a ‘deprofessionalisation’ of teaching, in some countries, such as England, the current rhetoric stresses the government’s trust in teachers and talk of ‘professional autonomy’ has come to the forefront. In light of this, a more rigorous understanding of the role of autonomy in teaching expertise seems necessary. This paper asks whether the notion of autonomy is significant to teachers’ roles and activities, and explores how autonomy bears on our conception of teaching expertise. The first part of the paper clarifies the very conception of autonomy that is employed in much philosophical discussion. I will argue that the notion of autonomy is problematic: it conflates rather different psychological, phenomenological and normative elements. When we clarify these ideas we can see how some of these aspects are in fact extremely relevant to our conception of the role of teachers and to our understanding of teaching practice. In the second part of the paper, these concepts are employed to clarify public debates surrounding teachers’ autonomy, comparing England and Scotland. I will claim that the kinds of knowledge and abilities constituting teaching expertise depend on our understanding of the role of teachers within an educational system and in relation to educational aims. This, in turn, has consequences for the way in which teaching expertise can be developed and/or hindered through policy

The concept of transport capacity in geomorphology

The notion of sediment-transport capacity has been engrained in geomorphological and related literature for over 50 years, although its earliest roots date back explicitly to Gilbert in fluvial geomorphology in the 1870s and implicitly to eighteenth to nineteenth century developments in engineering. Despite cross fertilization between different process domains, there seem to have been independent inventions of the idea in aeolian geomorphology by Bagnold in the 1930s and in hillslope studies by Ellison in the 1940s. Here we review the invention and development of the idea of transport capacity in the fluvial, aeolian, coastal, hillslope, débris flow, and glacial process domains. As these various developments have occurred, different definitions have been used, which makes it both a difficult concept to test, and one that may lead to poor communications between those working in different domains of geomorphology. We argue that the original relation between the power of a flow and its ability to transport sediment can be challenged for three reasons. First, as sediment becomes entrained in a flow, the nature of the flow changes and so it is unreasonable to link the capacity of the water or wind only to the ability of the fluid to move sediment. Secondly, environmental sediment transport is complicated, and the range of processes involved in most movements means that simple relationships are unlikely to hold, not least because the movement of sediment often changes the substrate, which in turn affects the flow conditions. Thirdly, the inherently stochastic nature of sediment transport means that any capacity relationships do not scale either in time or in space. Consequently, new theories of sediment transport are needed to improve understanding and prediction and to guide measurement and management of all geomorphic systems

Effect of angiotensin-converting enzyme inhibitor and angiotensin receptor blocker initiation on organ support-free days in patients hospitalized with COVID-19

IMPORTANCE Overactivation of the renin-angiotensin system (RAS) may contribute to poor clinical outcomes in patients with COVID-19. Objective To determine whether angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB) initiation improves outcomes in patients hospitalized for COVID-19. DESIGN, SETTING, AND PARTICIPANTS In an ongoing, adaptive platform randomized clinical trial, 721 critically ill and 58 non–critically ill hospitalized adults were randomized to receive an RAS inhibitor or control between March 16, 2021, and February 25, 2022, at 69 sites in 7 countries (final follow-up on June 1, 2022). INTERVENTIONS Patients were randomized to receive open-label initiation of an ACE inhibitor (n = 257), ARB (n = 248), ARB in combination with DMX-200 (a chemokine receptor-2 inhibitor; n = 10), or no RAS inhibitor (control; n = 264) for up to 10 days. MAIN OUTCOMES AND MEASURES The primary outcome was organ support–free days, a composite of hospital survival and days alive without cardiovascular or respiratory organ support through 21 days. The primary analysis was a bayesian cumulative logistic model. Odds ratios (ORs) greater than 1 represent improved outcomes. RESULTS On February 25, 2022, enrollment was discontinued due to safety concerns. Among 679 critically ill patients with available primary outcome data, the median age was 56 years and 239 participants (35.2%) were women. Median (IQR) organ support–free days among critically ill patients was 10 (–1 to 16) in the ACE inhibitor group (n = 231), 8 (–1 to 17) in the ARB group (n = 217), and 12 (0 to 17) in the control group (n = 231) (median adjusted odds ratios of 0.77 [95% bayesian credible interval, 0.58-1.06] for improvement for ACE inhibitor and 0.76 [95% credible interval, 0.56-1.05] for ARB compared with control). The posterior probabilities that ACE inhibitors and ARBs worsened organ support–free days compared with control were 94.9% and 95.4%, respectively. Hospital survival occurred in 166 of 231 critically ill participants (71.9%) in the ACE inhibitor group, 152 of 217 (70.0%) in the ARB group, and 182 of 231 (78.8%) in the control group (posterior probabilities that ACE inhibitor and ARB worsened hospital survival compared with control were 95.3% and 98.1%, respectively). CONCLUSIONS AND RELEVANCE In this trial, among critically ill adults with COVID-19, initiation of an ACE inhibitor or ARB did not improve, and likely worsened, clinical outcomes. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT0273570

Stephen Peterson : Shadows & Traces : Re/Collections

Arnott outlines the formal references which make Peterson's installation an homage to his late grandfather. Biographical notes. 4 bibl. ref

Marsha Kennedy : Phantom Limbs

Arnott analyzes Kennedy's installations in light of the profound concern for the environment and belief that humankind and nature are one. Biographical notes