Variable anodic thermal control coating

A process for providing a thermal control solar stable surface coating for aluminum surfaces adapted to be exposed to solar radiation wherein selected values within the range of 0.10 to 0.72 thermal emittance (epsilon sub tau) and 0.2 to 0.4 solar absorptance (alpha subs) are reproducibly obtained by anodizing the surface area in a chromic acid solution for a selected period of time. The rate voltage and time, along with the parameters of initial epsilon sub tau and alpha subs, temperature of the chromic acid solution, acid concentration of the solution and the material anodized determines the final values of epsilon/tau sub and alpha sub S. 9 Claims, 5 Drawing Figures

Experimental analysis of sample-based maps for long-term SLAM

This paper presents a system for long-term SLAM (simultaneous localization and mapping) by mobile service robots and its experimental evaluation in a real dynamic environment. To deal with the stability-plasticity dilemma (the trade-off between adaptation to new patterns and preservation of old patterns), the environment is represented at multiple timescales simultaneously (5 in our experiments). A sample-based representation is proposed, where older memories fade at different rates depending on the timescale, and robust statistics are used to interpret the samples. The dynamics of this representation are analysed in a five week experiment, measuring the relative influence of short- and long-term memories over time, and further demonstrating the robustness of the approach

Using structure-based organic chemistry online tutorials with automated correction for student practice and review

This article describes the development and implementation of an open-access organic chemistry question bank for online tutorials and assessments at University College Cork and Dublin Institute of Technology. SOCOT (structure-based organic chemistry online tutorials) may be used to supplement traditional small-group tutorials, thereby allowing students to develop essential problem-solving skills in organic chemistry. This online approach may be used for both formative and summative assessment. Students complete one problem set weekly or fortnightly, which consists of a number of questions of varying difficulty. A wide range of question types is possible; for example, prediction of reaction products, identification of reaction intermediates or reagents, and retrosynthetic analyses. Questions involving stereochemistry may be also be incorporated. The implementation is described, along with several sample questions and advice for creating questions. This approach is suitable for all levels of undergraduates, from introductory nonmajors to final-year chemistry students. Student feedback was overwhelmingly positive, and in particular, students found SOCOT to be a quite useful tool for review purposes. Our approach uses MarvinSketch, which is free for academic purposes, and the SMILES algorithm, which converts chemical structures into a text string and is compatible with any learning management system

Why do authoritarian regimes provide public goods? Policy communities, external shocks and ideas in China’s rural social policy making

Recent research on authoritarian regimes argues that they provide public goods in order to prevent rebellion. This essay shows that the ‘threat of rebellion’ alone cannot explain Chinese party-state policies to extend public goods to rural residents in the first decade of the twenty-first century. Drawing on theories of policy making, it argues that China’s one-party regime extended public goods to the rural population under the influence of ideas and policy options generated by policy communities of officials, researchers, international organisations and other actors. The party-state centre adopted and implemented these ideas and policy options when they provided solutions to external shocks and supported economic development goals. Explanations of policies and their outcomes in authoritarian political systems need to include not only ‘dictators’ but also other actors, and the ideas they generate

Cryptogamic ground covers as analogues for early terrestrial biospheres: Initiation and evolution of biologically mediated proto-soils

Modern cryptogamic ground covers (CGCs), comprising assemblages of bryophytes (hornworts, liverworts, mosses), fungi, bacteria, lichens and algae, are thought to resemble early divergent terrestrial communities. However, limited in-situ plant and other fossils in the rock record, and a lack of CGC-like soils reported in the pre-Silurian sedimentological record, have hindered understanding of the structure, composition, and interactions within the earliest CGCs. A key question is how the earliest CGC-like organisms drove weathering on primordial terrestrial surfaces (regolith), leading to the early stages of soil development as proto-soils, and subsequently contributing to large-scale biogeochemical shifts in the Earth System. Here, we employed a novel qualitative, quantitative and multi-dimensional imaging approach through X-ray micro-computed tomography, scanning electron, and optical microscopy to investigate whether different combinations of modern CGC organisms from primordial-like settings in Iceland develop organism-specific soil-forming features at the macro- and micro-scales. Additionally, we analysed CGCs growing on hard rocky substrates to investigate the initiation of weathering processes non-destructively in 3D. We show that thalloid CGC organisms (liverworts, hornworts) develop thin organic layers at the surface (<1 cm) with limited subsurface structural development, whereas leafy mosses and communities of mixed-organisms form profiles that are thicker (up to ~7 cm), structurally more complex, and more organic-rich. We term these thin layers and profiles proto-soils. Component analyses from X-ray micro-computed tomography data show that thickness and structure of these proto-soils are determined by the type of colonising organism(s), suggesting that the evolution of more complex soils through the Palaeozoic may have been driven by a shift in body plan of CGC-like organisms from flattened and appressed to upright and leafy. Our results provide a framework for identifying CGC-like proto-soils in the rock record and a new proxy for understanding organism-soil interactions in ancient terrestrial biospheres and their contribution to the early stages of soil-formation

The gene product Murr1 restricts HIV-1 replication in resting CD4(+) lymphocytes

Although human immunodeficiency virus-1 (HIV-1) infects quiescent and proliferating CD4(+) lymphocytes, the virus replicates poorly in resting T cells(1-6). Factors that block viral replication in these cells might help to prolong the asymptomatic phase of HIV infection(7); however, the molecular mechanisms that control this process are not fully understood. Here we show that Murr1, a gene product known previously for its involvement in copper regulation(8,9), inhibits HIV-1 growth in unstimulated CD4(+) T cells. This inhibition was mediated in part through its ability to inhibit basal and cytokine-stimulated nuclear factor (NF)-kappaB activity. Knockdown of Murr1 increased NF-kappaB activity and decreased IkappaB-alpha concentrations by facilitating phospho-IkappaB-alpha degradation by the proteasome. Murr1 was detected in CD4(+) T cells, and RNA-mediated interference of Murr1 in primary resting CD4(+) lymphocytes increased HIV-1 replication. Through its effects on the proteasome, Murr1 acts as a genetic restriction factor that inhibits HIV-1 replication in lymphocytes, which could contribute to the regulation of asymptomatic HIV infection and the progression of AIDS.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/62709/1/nature02171.pd

A novel role for XIAP in copper homeostasis through regulation of MURR1

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/102131/1/emboj7600031.pd

Echocardiographic description and outcomes in a heterogeneous cohort of patients undergoing mitral valve surgery with and without mitral annular disjunction: a health service evaluation.

BACKGROUND: Mitral annular disjunction (MAD) is a structural abnormality characterized by the distinct separation of the mitral valve annulus/left atrium wall and myocardium. Little is known about the significance of MAD in patients requiring mitral valve surgery. This evaluation evaluates the echocardiographic characteristics and patient outcomes for patients with and without MAD who require mitral valve surgery. METHODS: All patients who underwent mitral valve surgery and who had a pre-surgical transthoracic echocardiogram between 2013 and 2020 were included. Patient demographics and clinical outcomes were collected on review of patient electronic records. RESULTS: A total of 185 patients were included in the analysis of which 32.4% had MAD (average MAD length 8.4 mm). MAD was seen most commonly in patients with mitral valve prolapse and myxomatous mitral valves disease (90% and 60% respectively). In the patients with MAD prior to mitral valve surgery, only 3.9% had MAD post mitral valve surgery. There were no significant difference in the severity of post-operative mitral regurgitation, arrhythmic events or major adverse cardiovascular events in patients with and without MAD. CONCLUSIONS: MAD is common in patients who undergo mitral valve surgery. Current surgical techniques are able to correct the MAD abnormality in the vast majority of patients. MAD is not associated with an increased risk of adverse clinical outcomes post mitral valve surgery

Absence of differential predation on rats by Malaysian Barn Owls in oil palm plantations

Barn Owls (Tyto alba javanica) have been widely introduced in Malaysian oil palm plantations to control rodent pests. However, their effectiveness in regulating rodent populations is unknown. We investigated whether Barn Owls selected prey with respect to size and sex classes based on data from 128 pellets of Barn Owls compared to 1292 live-trapped rats in an oil palm plantation in Malaysia. The birds mostly fed on Rattus rail as diardii, the most commonly trapped species. Body mass of prey consumed was predicted based on models derived from measurements from trapped rats. Sex of prey was determined by pelvic measurements with reference to those taken from specimens of known gender. There was no clear selection of prey by Barn Owls in relation to size or sex of prey, and no difference in the body mass of prey between the owls' breeding and nonbreeding seasons. The absence of differential predation in Barn Owls may partly explain the lack of dear evidence that they regulate rodent populations and thus act as successful biological control agents