132 research outputs found

    Evaluation of Dynamic Cell Processes and Behavior Using Video Bioinformatics Tools

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    Just as body language can reveal a person’s state of well-being, dynamic changes in cell behavior and morphology can be used to monitor processes in cultured cells. This chapter discusses how CL-Quant software, a commercially available video bioinformatics tool, can be used to extract quantitative data on: (1) growth/proliferation, (2) cell and colony migration, (3) reactive oxygen species (ROS) production, and (4) neural differentiation. Protocols created using CL-Quant were used to analyze both single cells and colonies. Time-lapse experiments in which different cell types were subjected to various chemical exposures were done using Nikon BioStations. Proliferation rate was measured in human embryonic stem cell colonies by quantifying colony area (pixels) and in single cells by measuring confluency (pixels). Colony and single cell migration were studied by measuring total displacement (distance between the starting and ending points) and total distance traveled by the colonies/cells. To quantify ROS production, cells were pre-loaded with MitoSOX Redℱ, a mitochondrial ROS (superoxide) indicator, treated with various chemicals, then total intensity of the red fluorescence was measured in each frame. Lastly, neural stem cells were incubated in differentiation medium for 12 days, and time lapse images were collected daily. Differentiation of neural stem cells was quantified using a protocol that detects young neurons. CLQuant software can be used to evaluate biological processes in living cells, and the protocols developed in this project can be applied to basic research and toxicological studies, or to monitor quality control in culture facilities

    Joint Resummation for Higgs Production

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    We study the application of the joint resummation formalism to Higgs production via gluon-gluon fusion at the LHC, defining inverse transforms by analytic continuation. We work at next-to-leading logarithmic accuracy. We find that at low Q_T the resummed Higgs Q_T distributions are comparable in the joint and pure-Q_T formalisms, with relatively small influence from threshold enhancement in this range. We find a modest (about ten percent) decrease in the inclusive cross section, relative to pure threshold resummation.Comment: 22 pages, LaTeX, 5 figures as eps file

    Researching men who pay for sex: Using online methods for recruiting and interviewing

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    The use of online tools for recruitment and data collection are increasingly offering researchers access to hard to reach groups, and providing data about sensitive topics that were previously inaccessible to the research community. In this article, drawing on the experience of researching men who pay for sex with female sex workers in the United Kingdom, I explore the complexities of conducting online research, arguing that online research is indeed a valuable research tool, but that it should not be seen as the ‘easy’ option. This article outlines my rationale for using online methods and how traditional interview and recruitment practices and ethical issues were altered by this approach. A discussion of transformations in space and time follows. Finally, I reflect on how engaging with certain methods can reveal insights into the practices of those we research

    Centrioles: active players or passengers during mitosis?

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    Centrioles are cylinders made of nine microtubule (MT) triplets present in many eukaryotes. Early studies, where centrosomes were seen at the poles of the mitotic spindle led to their coining as “the organ for cell division”. However, a variety of subsequent observational and functional studies showed that centrosomes might not always be essential for mitosis. Here we review the arguments in this debate. We describe the centriole structure and its distribution in the eukaryotic tree of life and clarify its role in the organization of the centrosome and cilia, with an historical perspective. An important aspect of the debate addressed in this review is how centrioles are inherited and the role of the spindle in this process. In particular, germline inheritance of centrosomes, such as their de novo formation in parthenogenetic species, poses many interesting questions. We finish by discussing the most likely functions of centrioles and laying out new research avenues

    Chitosan–Starch–Keratin composites: Improving thermo-mechanical and degradation properties through chemical modification

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    The lysozyme test shows an improved in the degradability rate, the weight loss of the ïŹlms at 21 days is reduced from 73 % for chitosan-starch matrix up to 16 % for the composites with 5wt% of quill; but all ïŹlms show a biodegradable character depending on keratin type and chemical modiïŹcation. The outstanding properties related to the addition of treated keratin materials show that these natural composites are a remarkable alternative to potentiat-ing chitosan–starch ïŹlms with sustainable featuresChitosan–starch polymers are reinforced with diïŹ€erent keratin materials obtained from chicken feather. Keratin materials are treated with sodium hydroxide; the modiïŹed surfaces are rougher in comparison with untreated surfaces, observed by Scanning Electron Microscopy. The results obtained by DiïŹ€erential Scanning Calorimetry show an increase in the endothermic peak related to water evaporation of the ïŹlms from 92 °C (matrix) up to 102–114 °C (reinforced composites). Glass transition temperature increases from 126 °C in the polymer matrix up to 170–200 °C for the composites. Additionally, the storage modulus in the composites is enhanced up to 1614 % for the composites with modiïŹed ground quill, 2522 % for composites with modiïŹed long ïŹber and 3206 % for the composites with modiïŹed short ïŹber. The lysozyme test shows an improved in the degradability rate, the weight loss of the ïŹlms at 21 days is reduced from 73 % for chitosan-starch matrix up to 16 % for the composites with 5wt% of quill; but all ïŹlms show a biodegradable character depending on keratin type and chemical modiïŹcation. The outstanding properties related to the addition of treated keratin materials show that these natural composites are a remarkable alternative to potentiat-ing chitosan–starch ïŹlms with sustainable featuresUniversidad AutĂłnoma del Estado de MĂ©xico TecnolĂłgico Nacional de MĂ©xico, Instituto TecnolĂłgico de QuerĂ©taro Universidad Nacional AutĂłnoma de MĂ©xico TecnolĂłgico Nacional de MĂ©xico, Instituto TecnolĂłgico de Celaya Universidad AutĂłnoma de Cd. JuĂĄre

    Planning southern Iraq: placing the progressive theories of Max Lock in Um Qasr, Margil, and Basra in the context of Iraqi national development, 1954–1956

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    Between 1954 and 1956, the architect, educator, and planner, Max Lock (1909–1988) produced a trilogy of plans to modernize the historical city of Basra and create new areas at Margil and Um Qasr in the south of Iraq. The New Basrah Plan was heavily inspired by the works of Patrick Geddes and aligned with contemporaries such as Lewis Mumford, Lock’s planning was progressive in scope and looked to differ from the planning of post-war principles in Britain through his notions of ‘civic surgery’. Contrary to this, his plans for Um Qasr and Margil focussed on infrastructure and the creation of more industrial areas not prioritizing people and place as highly as he did in the New Basrah Plan. Lock’s ‘Civic Surgery’ offered an alternative to mainstream thought by attempting to create usable, humanistic spaces, which hampered by politics and legislation, resulted in the plan’s shelving and were contradicted by his other works’ philosophies. New retrospective analysis of his underappreciated career reveals the complexities of his planning which this article demonstrates through the ‘failure’ of the New Basrah Plan and his plans at Um Qasr and Margil

    Molecular mechanisms of cell death: recommendations of the Nomenclature Committee on Cell Death 2018.

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    Over the past decade, the Nomenclature Committee on Cell Death (NCCD) has formulated guidelines for the definition and interpretation of cell death from morphological, biochemical, and functional perspectives. Since the field continues to expand and novel mechanisms that orchestrate multiple cell death pathways are unveiled, we propose an updated classification of cell death subroutines focusing on mechanistic and essential (as opposed to correlative and dispensable) aspects of the process. As we provide molecularly oriented definitions of terms including intrinsic apoptosis, extrinsic apoptosis, mitochondrial permeability transition (MPT)-driven necrosis, necroptosis, ferroptosis, pyroptosis, parthanatos, entotic cell death, NETotic cell death, lysosome-dependent cell death, autophagy-dependent cell death, immunogenic cell death, cellular senescence, and mitotic catastrophe, we discuss the utility of neologisms that refer to highly specialized instances of these processes. The mission of the NCCD is to provide a widely accepted nomenclature on cell death in support of the continued development of the field
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