818 research outputs found

    Simultaneous Brownian Motion of N Particles in a Temperature Gradient

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    A system of N Brownian particles suspended in a nonuniform heat bath is treated as a thermodynamic system whith internal degrees of freedom, in this case their velocities and coordinates. Applying the scheme of non-equilibrium thermodynamics, one then easily obtains the Fokker-Planck equation for simultaneous Brownian motion of N particles in a temperature gradient. This equation accounts for couplings in the motion as a result of hydrodynamic interactions between particles.Comment: 9 pages, RevTe

    LASER INACTIVATION OF THE GENERATIVE NUCLEUS IN AMARYLLIS POLLEN

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    Review of \u3ci\u3eIndigenous Dance and Dancing Indian: Contested Representation in the Global Era\u3c/i\u3e by Matthew Krystal

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    This is a thoughtful, helpful, somewhat unusually focused book that looks at K\u27iche Maya Traditional Dance in Guatemala, Native American Powwow (particularly in the Upper Midwest), Folkloric dance in the Chicago area, and at the University of Illinois\u27s Chief Illiniwek dancing mascot from an anthropologically informed ethnographic perspective. The section on Maya dance comes from the author\u27s dissertation research, while the sections on Indigenous dance and playing Indian in the Midwest are from fieldwork he has undertaken, postdissertation, while teaching at North Central College in Illinois. Krystal brings these diverse performance practices into dialogue with each other by looking at them all through anthropological discourse around ritual and the enactment of identity, as well as through insightful considerations of how these practices relate to discussions of such topics as authentity and tradition

    Talking Business on Twitter

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    In 2013, creating healthy relationships with your publics is imperative for growth and maintaining already loyal constituents. Twitter has become a concise, yet direct way to communicate with your followers. There are five key findings on how Twitter affects organizations. Personal dialogue is key; it makes the followers feel more personable and more likely to engage in conversation. The digital media age is a world in which most information we receive is through internet and social media vehicles. With Twitter, communicating with the public while gaining visible exposure is quite simple. “In reality, few organizations reach a high level of interactivity. Few websites go beyond providing content for constituents and providing a mechanism for feedback.” In order to find data, the website instituteforpr.org is used. This site shares case studies on how people use Twitter for their organizations. Through the four-week study and observing other opinions regarding the power of the internet, using Twitter can boost your public reputation as well as bring in growth. In conclusion, we hope to share information on how organizations can make their organization better by “Talking Business on Twitter.

    Dancing the Pluriverse: Indigenous Performance as Ontological Praxis

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    This article discusses ways that Indigenous dance is an ontological praxis that is embodied and telluric, meaning “of the earth.” It looks at how dancing bodies perform in relationship to ecosystems and entities within them, producing ontological distinctions and hierarchies that are often imbued with power. This makes dance a site of ontological struggle that potentially challenges the delusional ontological universality undergirding imperialism, genocide, and ecocide. The author explores these theoretical propositions through her participation in Oxlaval Q'anil, an emerging Ixil Maya dance project in Guatemala, and Dancing Earth, an itinerant and inter-tribal U.S.-based company founded by Rulan Tangen eleven years ago

    Corrigendum to “Effects of therapeutic hypothermia on the gut microbiota and metabolome of infants suffering hypoxic-ischemic encephalopathy at birth” [Int. J. Biochem. Cell Biol. 93 (December) (2017), 110-118]

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    peer-reviewedCorrigendum Refers to: Watkins, C., Murphy, K., Yen, S., Carafa, I., Dempsey, E., O’Shea, C., Vercoe, E., Ross, R., Stanton, C. and Ryan, C. (2017). Effects of therapeutic hypothermia on the gut microbiota and metabolome of infants suffering hypoxic-ischemic encephalopathy at birth. The International Journal of Biochemistry & Cell Biology, [online] 93, pp.110-118. Available at: https://doi.org/10.1016/j.biocel.2017.08.01

    Teaching presence in computer conferencing learning environments: Effects on interaction, cognition and learning uptake

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    This exploratory study examined how the level and nature of teaching presence impacted two online forum discussions from three dimensions: participation and interaction, cognitive presence, and knowledge development via assimilating peer messages. Effects on participation and interaction were graphically depicted. Effects on cognitive presence and knowledge construction via assimilating messages were suggested via statistical analysis, followed by qualitative interpretations. Twenty-six tertiary online learners with varied demographic backgrounds participated in the study for 6 weeks. The results showed that the nature of teaching presence in the study, specified to teacher initiation, roles of teaching presence and means of making teaching presence, largely shaped the impact of teaching presence on learning. A higher level of teaching presence was observed to be associated with a lower level of student participation, peer interaction, cognitive presence and learning uptake. Based on the results, implications for integrating and researching teaching presence in computer conferences were provided

    Sub-cortical and brainstem sites associated with chemo-stimulated increases in ventilation in humans

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    We investigated the neural basis for spontaneous chemo-stimulated increases in ventilation in awake, healthy humans. Blood oxygen level dependent (BOLD) functional MRI was performed in nine healthy subjects using T2weighted echo planar imaging. Brain volumes (52 transverse slices, cortex to high spinal cord) were acquired every 3.9 s. The 30 min paradigm consisted of six, 5-min cycles, each cycle comprising 45 s of hypoxic-isocapnia, 45 s of isooxic-hypercapnia and 45 s of hypoxic-hypercapnia, with 55 s of non-stimulatory hyperoxic-isocapnia (control) separating each stimulus period. Ventilation was significantly (p < 0.001) increased during hypoxic-isocapnia, isooxic-hypercapnia and hypoxic-hypercapnia (17.0, 13.8, 24.9 L/min respectively) vs. control (8.4 L/min) and was associated with significant (p < 0.05, corrected for multiple comparisons) signal increases within a bilateral network that included the basal ganglia, thalamus, red nucleus, cerebellum, parietal cortex, cingulate and superior mid pons. The neuroanatomical structures identified provide evidence for the spontaneous control of breathing to be mediated by higher brain centres, as well as respiratory nuclei in the brainstem

    Uniform deposition of protein incorporated mineral layer on three-dimensional porous polymer scaffolds

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    Inorganic–organic hybrid materials designed to facilitate bone tissue regeneration use a calcium phosphate mineral layer to encourage cell adhesion, proliferation, and osteogenic differentiation. Mineral formed on porous materials is often discontinuous through the thickness of the scaffold. This study aimed to uniformly coat the pores of three-dimensional (3D) porous, polymer scaffolds with a bone-like mineral layer in addition to uniformly incorporating a model protein within this mineral layer. A filtration system designed to induce simulated body fluid flow through the interstices of 3D polylactic- co -glycolic acid scaffolds (10-mm diameter × 2-mm thickness) illustrated that a uniform, continuous mineral layer can be precipitated on the pore surfaces of a 3D porous structure within 5 days. MicroCT analysis showed increased mineral volume percent (MV%) (7.86 ± 3.25 MV%, p = 0.029) and continuous mineralization of filtered scaffolds compared with two static control groups (floating, 0.16 ± 0.26 MV% and submerged, 0.20 ± 0.01 MV%). Furthermore, the system was effective in coprecipitating a model protein, bone sialoprotein (BSA), within the mineral layer. A 10-fold increase in BSA incorporation was seen when coprecipitated filtered scaffolds (1308 ± 464 Μg) were compared to a submerged static control group (139 ± 45 Μg), p < 0.001. Confocal microscopy visually confirmed uniform coprecipitation of BSA throughout the thickness of the filtration scaffolds. The designed system enables 3D mineralization through the thickness of porous materials, and provides the option of including coprecipitated biomolecular cues within the mineral layer. This approach of providing a 3D conductive and osteoinductive environment could be conducive to bone tissue regeneration. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 2008Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/57926/1/30877_ftp.pd

    Dynamical Analysis on Gene Activity in the Presence of Repressors and an Interfering Promoter

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    Transcription is regulated through interplay between transcription factors, an RNA polymerase(RNAP), and a promoter. Even for a simple repressive transcription factor that disturbs promoter activity at the initial binding of RNAP, its repression level is not determined solely by the dissociation constant of transcription factor but is sensitive to the time scales of processes in RNAP. We first analyse the promoter activity under strong repression by a slow binding repressor, in which case transcriptions occur in a burst, followed by a long quiescent period while a repressor binds to the operator; the number of transcriptions, the bursting and the quiescent times are estimated by reaction rates. We then examine interference effect from an opposing promoter, using the correlation function of transcription initiations for a single promoter. The interference is shown to de-repress the promoter because RNAP's from the opposing promoter most likely encounter the repressor and remove it in case of strong repression. This de-repression mechanism should be especially prominent for the promoters that facilitate fast formation of open complex with the repressor whose binding rate is slower than about 1/sec. Finally, we discuss possibility of this mechanism for high activity of promoter PR in the hyp-mutant of lambda phage.Comment: supplement is attache
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