850 research outputs found

    A three-component theory of sedimentation equilibrium in a density gradient

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    In the original analysis (1) of the behavior of macromolecules and viruses in a density gradient at equilibrium in the ultracentrifuge, only two incompressible components were considered to be present. These were the polymer and the solvent which forms the density gradient. The pressure-dependent terms and the cross terms in the chemical potential which describe the chemical reactions between the polymer and the solute were neglected. It has been pointed out from theoretical considerations (2-4) that these terms are important. In experimental studies of the buoyant behavior of bovine mercaptalbumin in aqueous cesium chloride,(5) it was observed that both solvation and pressure effects are large

    Escape from the List: Courage, Sacrifice, Survival

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    Anne Frank has been described as Hitler’s most famous victim. By virtue of her diary, which was in fact a heavily revised memoir that today might be considered to belong to the genre of creative non-fiction, Anne Frank has attained a kind of immortality that the art form of writing frequently provides. This should not, of course, trivialize her fate, nor the suffering of the multitudes of other victims of the Nazi regime, a group comprised of Jews, as well as non-Jews. Some of these stories have been told in great detail, while many others have not. What follows is the story of Elisabeth Rodrigues Lopes de la Peña, a Jewish girl whose family had fled the Spanish Inquisition to settle in the Netherlands. During the German occupation of Amsterdam during the Second World War, this family faced yet another existential threat, one that some of them did not survive. Elisabeth may well have ended up as yet one more entry in the long list of the Nazi’s victims, if not for the intervention and courageous efforts of her non-Jewish neighbors—efforts that were based in large part on their own deeply held religious beliefs and sense of morals. Elisabeth’s rescuers are known to Holocaust historians, and their names are enshrined in the Yad Vashem World Holocaust Remembrance Museum in Israel, as well as in the United States Holocaust Memorial Museum in Washington, DC. Along with my Research Assistant Angelica Roman, I have conducted personal meetings and interviews with Elisabeth’s daughter, Carolyn Stewart. Ms. Stewart has graciously shared many heretofore unknown details of her mother’s story of rescue, as well as photographs and documents, including some that have been unseen by anyone in over sixty years. What follows is new insight into Elisabeth Rodrigues’ escape from the list: a true story of courage, sacrifice, and survival. I would like to acknowledge with gratitude the assistance and support of the following people: Jennifer Crespo, Student Success Coordinator at Pace University in New York City, who generously provided funding for this project as part of the Pace Undergraduate Student – Faculty Research Program; Bonnie and Howard J. Price, without whose help this project would never have seen the light of day; my colleague at Pace University Dr. Maria Plochocki, for reviewing the manuscript and providing valuable suggestions; Gertjan Broek and Karolien Stocking Korzen at the Anne Frank House in Amsterdam; Beth Slepian at The Anne Frank Center NYC, and my superbly talented Research Assistant, Angelica E. Roman ‘19, who tirelessly conducted research, helped revise early drafts, and patiently fielded a multitude of my requests while putting up with my numerous anxieties. Special thanks go to Carolyn Stewart, who traveled from Maryland to New York City for interviews, and who spent many hours communicating with Angelica and me over the course of several months. Carolyn shared many details and primary historical artifacts with us, and she relates her mother’s fascinating tale in a captivating and compelling manner. Our hope is that we can do this wonderful, inspiring story justice in the pages that follow

    Potential Function Describing the Folding of the 30 nm Fiber

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    Multi Visualization and Dynamic Query for Effective Exploration of Semantic Data

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    Semantic formalisms represent content in a uniform way according to ontologies. This enables manipulation and reasoning via automated means (e.g. Semantic Web services), but limits the user’s ability to explore the semantic data from a point of view that originates from knowledge representation motivations. We show how, for user consumption, a visualization of semantic data according to some easily graspable dimensions (e.g. space and time) provides effective sense-making of data. In this paper, we look holistically at the interaction between users and semantic data, and propose multiple visualization strategies and dynamic filters to support the exploration of semantic-rich data. We discuss a user evaluation and how interaction challenges could be overcome to create an effective user-centred framework for the visualization and manipulation of semantic data. The approach has been implemented and evaluated on a real company archive

    Global hydrodynamic analysis of the molecular flexibility of galactomannans

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    In the past, intrinsic viscosity and sedimentation velocity analyses have been used separately to assess the conformation and flexibility of guar and locust bean gum galactomannans based on worm-like chain and semi-flexible coil models. Publication of a new global method combining data sets of both intrinsic viscosity and sedimentation coefficient with molecular weight, and minimising a target (error) function now permits a more robust analysis. Using this approach, values for the persistence length of (10 ± 2) nm for guar and (7 ± 1) nm for locust bean gum are returned if the mass per unit length ML is floated as a variable. Using a fixed mass per unit length based on the known compositional data of each galactomannan yields a similar value for Lp in both cases, (8 ± 1) nm for guar and (9 ± 1) nm for locust bean gum, with combined set of data yielding (9 ± 1) nm: within experimental error the flexibilities of both galactomannans are very similar. © 2007 Elsevier Ltd. All rights reserved

    A Review of Object Detection Models based on Convolutional Neural Network

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    Convolutional Neural Network (CNN) has become the state-of-the-art for object detection in image task. In this chapter, we have explained different state-of-the-art CNN based object detection models. We have made this review with categorization those detection models according to two different approaches: two-stage approach and one-stage approach. Through this chapter, it has shown advancements in object detection models from R-CNN to latest RefineDet. It has also discussed the model description and training details of each model. Here, we have also drawn a comparison among those models.Comment: 17 pages, 11 figures, 1 tabl

    Structure of psoralen-crosslinked ribosomal RNA from Drosophila melanogaster.

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