Reversing a granular flow on a vibratory conveyor

Experimental results are presented on the transport properties of granular materials on a vibratory conveyor. For circular oscillations of the shaking trough a non-monotonous dependence of the transport velocity on the normalized acceleration is observed. Two maxima are separated by a regime, where the granular flow is much slower and, in a certain driving range, even reverses its direction. A similar behavior is found for a single solid body with a low coefficient of restitution, whereas an individual glass bead of 1 mm diameter is propagated in the same direction for all accelerations.Comment: 4 pages, 5 figures, submitted to Applied Physics Letter

Spontaneous Ratchet Effect in a Granular Gas

The spontaneous clustering of a vibrofluidized granular gas is employed to generate directed transport in two different compartmentalized systems: a "granular fountain" in which the transport takes the form of convection rolls, and a "granular ratchet" with a spontaneous particle current perpendicular to the direction of energy input. In both instances, transport is not due to any system-intrinsic anisotropy, but arises as a spontaneous collective symmetry breaking effect of many interacting granular particles. The experimental and numerical results are quantitatively accounted for within a flux model.Comment: 4 pages, 5 figures; Fig. 4 has been reduced in size and qualit

Salivary gland-specific <i>P. berghei</i> reporter lines enable rapid evaluation of tissue-specific sporozoite loads in mosquitoes

Malaria is a life-threatening human infectious disease transmitted by mosquitoes. Levels of the salivary gland sporozoites (sgs), the only mosquito stage infectious to a mammalian host, represent an important cumulative index of &lt;i&gt;Plasmodium&lt;/i&gt; development within a mosquito. However, current techniques of sgs quantification are laborious and imprecise. Here, transgenic &lt;i&gt;P. berghei&lt;/i&gt; reporter lines that produce the green fluorescent protein fused to luciferase (GFP-LUC) specifically in sgs were generated, verified and characterised. Fluorescence microscopy confirmed the sgs stage specificity of expression of the reporter gene. The luciferase activity of the reporter lines was then exploited to establish a simple and fast biochemical assay to evaluate sgs loads in whole mosquitoes. Using this assay we successfully identified differences in sgs loads in mosquitoes silenced for genes that display opposing effects on &lt;i&gt;P. berghei&lt;/i&gt; ookinete/oocyst development. It offers a new powerful tool to study infectivity of &lt;i&gt;P. berghei&lt;/i&gt; to the mosquito, including analysis of vector-parasite interactions and evaluation of transmission-blocking vaccines

Combination therapy with bosentan and sildenafil for refractory digital ulcers and Raynaud’s phenomenon in a 30-year-old woman with systemic sclerosis: Case report and literature review

BACKGROUND: Systemic sclerosis is a rare autoimmune disease characterized by skin and organ fibrosis, and vasculopathy. Raynaud’s phenomenon is almost universally present in systemic sclerosis and can be the most debilitating symptom. Raynaud’s phenomenon may lead to the development of digital ulcers, potentially complicated by infection, tissue necrosis, and auto-amputation. Recommended treatments have variable efficacy. METHODS: We report the case of a 30-year-old woman with diffuse systemic sclerosis suffering from severe Raynaud’s phenomenon and digital ulcers with digital tissue necrosis who was treated with combination therapy of an endothelin receptor antagonist and phosphodiesterase 5 inhibitor. In addition, we reviewed the literature on the topic. RESULTS: Previous therapy with calcium-channel blockers, intravenous iloprost, and bosentan had all failed to control symptoms. We added sildenafil in combination with bosentan and observed a rapid and sustained treatment effect. Raynaud’s phenomenon severity, number of attacks, and attack duration decreased within 2 weeks of initiating treatment. Furthermore, this resulted in the healing of established digital ulcers. CONCLUSION: Our case report suggests that combination therapy may be a feasible treatment for the most severely affected and refractory patients. In our literature review, we found one retrospective study and three additional cases with similarly encouraging results

Climate Change and Indigenous Peoples in Latin America

This research focused on the detrimental effects of climate change on indigenous peoples in Latin America. Indigenous peoples throughout the region tend to live subsistence livelihoods, which tie them closely to their land and the surrounding environment. This close relationship often means that indigenous peoples acutely experience the effects of climate change and are more susceptible to its negative outcomes than other populations. Further, indigenous peoples in the region lack the mitigation and adaptation capacities to deal with damaging climatic effects. This research was designed to view the impacts of climate change on indigenous peoples through a human rights framework, focusing on the difficulties of resource allocation and management due to climatic shifts. Methods of critique were applied to international responses to climate issues. The research clearly shows the enhanced ways in which indigenous peoples are affected by climate change and that their circumstances inform their thoughts on both the problem and possible solutions. These perspectives are significant and should be more readily considered in international climate discourse

Molecular Mechanism of the pH-Dependent Calcium Affinity in Langerin

The C-type lectin receptor langerin plays a vital role in the mammalian defense against invading pathogens. Its function hinges on the affinity to its co-factor Ca2+ which in turn is regulated by the pH. We studied the structural consequences of pro-tonating the allosteric pH-sensor histidine H294 by molecular dynamics simulations (total simulation time: about 120 μs) and Markov models. We discovered a mechanism in which the signal that the pH has dropped is transferred to the Ca2+-binding site without transferring the initial proton. Instead, protonation of H294 unlocks a conformation in which a protonated lysine side-chain forms a hydrogen bond with a Ca2+-coordinating aspartic acid. This destabilizes Ca2+ in the binding pocket, which we probed by steered molecular dynamics. After Ca2+-release, the proton is likely transferred to the aspartic acid and stabilized by a dyad with a nearby glutamic acid, triggering a conformational transition and thus preventing Ca2+-rebinding

Зміна роздільної здатності зображень на основі власних векторів матриць-операторів індукованих з піксельних наборів

The method of problem solving increase resolution image sets provided that the dimension of the set. The method is to build a matrix operator and find its eigenvectors. Using sets of eigenvectors and matrix color images developed a practical set of algorithm changes the resolution

Automated glycan assembly of ¹⁹F labelled glycan probes enables high‐throughput NMR studies of protein‐glycan interactions

Protein‐glycan interactions mediate important biological processes, including pathogen host invasion and cellular communication. Major challenges to monitoring these low affinity interactions are the required high sensitivity of a biophysical assay and to cover a breath of synthetic well‐defined structures. Here, we showcase an expedite approach that integrates automated glycan assembly (AGA) of 19 F labelled probes and high‐throughput NMR methods, enabling the study of protein‐glycan interactions. Synthetic Lewis type 2 antigens were screened against seven glycan binding proteins (GBPs), including DC‐SIGN and BambL, respectively involved in HIV‐1 and lung infections in immunocompromised patients, confirming the preference for fucosylated glycans (Le x , H type 2, Le y ). Previously unknown glycan‐lectin weak interactions were detected, and thermodynamic data were obtained. Enzymatic reactions were monitored in real‐time, delivering kinetic parameters. These results demonstrate the utility of AGA combined with 19 F NMR for the discovery and characterization of glycan‐protein interactions, opening up new perspectives for 19 F labelled complex glycans