Applications of enantioselective halolactonization reactions, synthesis of photocaged compounds for identifying neurons based on function, and progress towards the total synthesis of alstoscholarisine E

Recently the Martin group developed a bifunctional organic catalyst that promotes highly efficient enantioselective halolactonization reactions for olefinic acids. Using the BINOL-amidine catalyst we invented, our group was able to perform halolactonization reactions on a broad array of substrates. Herein we describe the synthetic utility of this method through a concise synthesis of (+)-disparlure, along with the preparation of F ring synthons for the natural product kibdelone C. As part of a separate project, in collaboration with the Zemelman research group, we are working to design a system for identifying behaviorally relevant assemblies of neurons in awake animals. This novel technique identifies active neurons and tags them using fluorescent proteins that are expressed upon irradiation of the neuron with visible light. This system hinges on the preparation on light sensitive derivatives of a variety of repressor protein ligands using “cages” or “photocages.” Toward this end, we prepared photocaged derivatives of anhydrotetracycline and vanillic acid. Finally, we disclose our progress towards the total synthesis of alstoscholarisine E, a natural product isolated in 2014 that was found to be a strong promoter of adult neuronal stem cell proliferation. We envisioned a convergent synthesis where skatole and a hetero-Diels-Alder product could be joined through a metal catalyzed coupling to form the tetracyclic core of the molecule, which could then be easily transformed to alstoscholarisine E through an olefin reduction followed by a reductive cyclization. Accessing our desired hetero-Diels-Alder product quickly was paramount to the effectiveness of this route, and thus, we developed a method to access hetero-Diels-Alder precursors in one step starting from readily available hexahydrotriazines.Chemistr

Developing a Framework for Automated Scenario- Based e-Learning Design

Scenario-based e-learning can be used to enable students to develop expertise, in situations that are rare or infrequent, too hazardous for the inexperienced, too expensive to permit practice and failure, or simply not available. Developing automated courses requires significant technical ability, separate from the subject expertise of the educator. This paper introduces a framework developed to simplify this process, along with a scenario authoring and cloud-based training environment, Pandora

Взрывоопасность угольной пыли и метана в горном деле

Данная статья посвящена проблеме предотвращения аварий на предприятиях горнодобывающей промышленности за счёт влияния. Рассматриваются причины повышения содержания газа в горных выработках. Дана сравнительная характеристика угольной пыли и метана по их опасности. Выявлено, что угольная пыль опаснее метана. Приведены меры по профилактике аварийности на горнодобывающих предприятиях. This article is devoted to the prevention of accidents in the mining industry at the expense of influence. It discusses reasons for the increase in gas content in mine workings. The author describes comparative characteristics of coal dust and methane at their danger. It is revealed that the coal dust is more dangerous than methane. The author gives measures for the prevention of accidents at mining enterprises

Tighter bounding volumes for better occlusion culling performance

Bounding volumes are used in computer graphics to approximate the actual geometric shape of an object in a scene. The main intention is to reduce the costs associated with visibility or interference tests. The bounding volumes most commonly used have been axis-aligned bounding boxes and bounding spheres. In this paper, we propose the use of discrete orientation polytopes (\kdops) as bounding volumes for the specific use of visibility culling. Occlusion tests are computed more accurately using \kdops, but most importantly, they are also computed more efficiently. We illustrate this point through a series of experiments using a wide range of data models under varying viewing conditions. Although no bounding volume works the best in every situation, {\kdops} are often the best, and also work very well in those cases where they are not the best, therefore they provide good results without having to analyze applications and different bounding volumes

Mapeamento dos fluxos de processos operacionais na Agência de Inovação da Universidade Federal do Paraná

Orientador: Prof. Joel Souza e SilvaMonografia(Especialização) - Universidade Federal do Paraná,Setor de Ciências Sociais Aplicadas, Curso de Especialização em Gestão PúblicaResumo: O mapeamento e padronização das principais atividades existentes no setor auxiliam na analise dos processos de trabalho antecipadamente, identificar melhorias e promover ações corretivas, quando necessária, além de possibilitar a equipe enxergar a relação direta de seu serviço com os realizados pelos demais funcionários e o impacto de sua atividade no desempenho geral da instituição. E para que o mapeamento dos fluxos processuais seja eficiente toda a equipe, inclusive a administração da instituição e chefias devem envolver-se no projeto, de forma a incentivar a participação e comprometimento de todos. O treinamento e orientação em relação à padronização e metas estabelecidas também devem estar claros na mente dos funcionários. Após algumas analises, identificou-se a necessidade de desenvolver uma proposta de um mapeamento e padronização dos processos operacionais, para melhor o controle das atividades no setor e a melhoria na qualidade da prestação de serviços. Para tanto, foi realizado um levantamento das principais atividades. Em seguida desenhado o mapeamento dos principais processos e padronização das atividades críticas. Ao termino do projeto, os resultados alcançados foram positivos, pois os objetivos foram alcançados e auxiliarão no controle estratégico do setor de atuação

Velocity vector reconstruction for real‐time phase‐contrast MRI with radial Maxwell correction

Purpose To develop an auto-calibrated image reconstruction for highly accelerated multi-directional phase-contrast (PC) MRI that compensates for (1) reconstruction instabilities occurring for phase differences near urn:x-wiley:07403194:media:mrm29108:mrm29108-math-0003 and (2) phase errors by concomitant magnetic fields that differ for individual radial spokes. Theory and Methods A model-based image reconstruction for real-time PC MRI based on nonlinear inversion is extended to multi-directional flow by exploiting multiple flow-encodings for the estimation of velocity vectors. An initial smoothing constraint during iterative optimization is introduced to resolve the ambiguity of the solution space by penalizing phase wraps. Maxwell terms are considered as part of the signal model on a line-by-line basis to address phase errors by concomitant magnetic fields. The reconstruction methods are evaluated using simulated data and cross-sectional imaging of a rotating-disc, as well as in vivo for the aortic arch and cervical spinal canal at 3T. Results Real-time three-directional velocity mapping in the aortic arch is achieved at 1.8 × 1.8 × 6 mm3 spatial and 60 ms temporal resolution. Artificial phase wraps are avoided in all cases using the smoothness constraint. Inter-spoke differences of concomitant magnetic fields are effectively compensated for by the model-based image reconstruction with integrated radial Maxwell correction. Conclusion Velocity vector reconstructions based on nonlinear inversion allow for high degrees of radial data undersampling paving the way for multi-directional PC MRI in real time. Whether a spoke-wise treatment of Maxwell terms is required or a computationally cheaper frame-wise approach depends on the individual application