1,997 research outputs found
Understanding the behavioral and neural basis of the geomagnetic sense of Tritonia tetraquetra
No full textThe Earth’s magnetic field is often used by a variety of animals as a navigational tool. Animals may use their compass navigation to fix their position and determine their direction of movement. Oftentimes, a variety of complementary tools like, celestial cues may be used to assist compass navigation (Hill et al. 2012). These navigational abilities can promote reproductive success, food acquisition, and effective migration.
While compass navigation and orientation behavior has been well studied in birds (Wiltschko & Wiltschko 1972), sea turtles (Lohmann 1991), and other organisms, the underlying neural basis of these behaviors is less understood. In investigating the neurophysiology of vertebrate navigation, the animal is restrained and thus limited in exhibiting typical migratory behavior. Additionally, the complexity of vertebrate brain structure makes it difficult to identify specific neurons and neural circuits involved in navigation.
The large nudibranch mollusk, Tritonia tetraquetra is known to orient to the Earth’s magnetic field (Lohmann and Willows 1987). It has been hypothesized that T. tetraquetra use their magnetic sense in response to situations when primary navigational cues become undependable (Wyeth 2010). T. tetraquetra uses odor-gated rheotaxis (OGR) to detect predators, mates, and prey (Wyeth & Willows 2006). But, sometimes before the slug reaches the source of the odor, the odor plume may dissipate due to varying water flow direction. The slug may then benefit from switching to a secondary navigational tool, such as, magnetoreception (Wyeth 2010) when the odor cue is lost.
T. tetraquetra is a good model for studying the behavior and neural basis of navigation and magnetic sensing. Their navigational distances are short compared to
Morgan D. Linney 3
other animals, allowing behavioral experiments to be done in the lab. Additionally, they have a centralized nervous system with large orange and white neurons that make them easy to visualize and identify (Willows 1971). The majority of their neurons have been mapped and characterized. Past studies of the neural basis of T. tetraquetra magnetic sensing has begun to identify key neurons and potential uses of this navigational tool (Lohmann et al. 1991)
Silent no longer: Iranian memoir as Islamic feminism
No full textThis thesis explores Iranian memoirs as an Islamic feminist space. It details a brief history of Iran 1900-present, an exploration of Islam and its importance to women’s rights and the development, and lack there of, with reference to women’s roles in Iranian society throughout the past 100 years. The work argues that these memoirs create a space, much like western autobiographies, in which women can tell their stories and therefore create a history of their own through the pages of the memoir. This thesis assesses the differences between eastern and western feminist thought through examining the burgeoning discipline of Islamic feminism. The importance of understanding women’s roles in Islamic society through the lens of Islamic feminism, which is inherently more culturally sensitive to Iranian culture, is the foundation of this work. By exploring the memoir as a platform for Iranian female expression the goal of this work is to expound upon the definition of memoir, to allow the memoir to be seen as academic within the discipline of literature. Each section of this thesis explores parts of the history and development of Iran and its women. Breaking down women’s rights into public and private space, the interaction of men and women, education of women, historical development of the rights of women, the defining characteristics of Islamic feminism, what makes these memoirs literary in nature and finally dealing with the three memoirs in the all aforementioned contexts. Concluding the thesis with the argument that these memoirs allow Iranian women to become a part of history in their own context, and to hold onto the Iran that they love through their own words and memories in the pages of their memoirs.M.A.Includes bibliographical referencesIncludes vitaby Morgan D. Rautzha
Microbial sources of exocellular DNA in the ocean
No full text© The Author(s), 2022. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Linney, M. D., Eppley, J. M., Romano, A. E., Luo, E., DeLong, E. F., & Karl, D. M. Microbial sources of exocellular DNA in the ocean. Applied and Environmental Microbiology, 88(7), (2022): e02093-21, https://doi.org/10.1128/aem.02093-21.Exocellular DNA is operationally defined as the fraction of the total DNA pool that passes through a membrane filter (0.1 μm). It is composed of DNA-containing vesicles, viruses, and free DNA and is ubiquitous in all aquatic systems, although the sources, sinks, and ecological consequences are largely unknown. Using a method that provides separation of these three fractions, we compared open ocean depth profiles of DNA associated with each fraction. Pelagibacter-like DNA dominated the vesicle fractions for all samples examined over a depth range of 75 to 500 m. Viral DNA consisted predominantly of myovirus-like and podovirus-like DNA and contained the highest proportion of unannotated sequences. Euphotic zone free DNA (75 to 125 m) contained primarily bacterial and viral sequences, with bacteria dominating samples from the mesopelagic zone (500 to 1,000 m). A high proportion of mesopelagic zone free DNA sequences appeared to originate from surface waters, including a large amount of DNA contributed by high-light Prochlorococcus ecotypes. Throughout the water column, but especially in the mesopelagic zone, the composition of free DNA sequences was not always reflective of cooccurring microbial communities that inhabit the same sampling depth. These results reveal the composition of free DNA in different regions of the water column (euphotic and mesopelagic zones), with implications for dissolved organic matter cycling and export (by way of sinking particles and/or migratory zooplankton) as a delivery mechanism.This work was supported by the Simons Collaboration on Ocean Processes and Ecology (awards 329108 to D.M.K. and E.F.D., 721252 to D.M.K., and 721223 to E.F.D.)
1) False Creek Flats: What About the Others? 2) South Flatz: Community That Renovictz
No full textThe ECUAD DONOR MAP series is a zine and two posters connecting some of the biggest donors for our new campus to local gentrification and other Place-based violence. The series is by Mickey Vescera and Mickey Morgan for FALL 2020 SOCS-302 Ethics of Representation. Some questions we contemplated in the construction of these maps, and throughout our scholarship at Emily Carr University of Art + Design: How did we get here in this shiny new campus “owning” the Land? Who are our donors that paid for this? Where do we find them in our school and in our neighbourhoods? How much of the “property” in East Van do they own? What other capital investments do they hold? Who does our being here serve? And ultimately, how can we disrupt this built-in power imbalance to be better neighbours?
Sources and Resources: https://docs.google.com/document/d/e/2PACX-1vQvQDAIqTsATIoPqf257eXmXffUv9YuKilDGC0R_kTsgPkE2qWMHnTqInKrzJ_GUIxLl-j3wtzdXE2Z/pub?fbclid=IwAR2gyEUjI6fh4Yvceebo5GbSx5jh0lpnUR9r6BQaGDpEC3tQD4lV4QDXCZ
Data for "Fast Approximate STEM Image Simulations from a Machine Learning Model"
No full textThis data set contains all the data for the following paper:
Fast Approximate STEM Image Simulations from a Machine
Learning Model, Aidan H. Combs, Jason J. Maldonis, Jie Feng, Zhongnan Xu, Paul
M. Voyles, Dane Morgan, published in the journal Advanced Structural and Chemical Imaging (2019).
DOI : 10.1186/s40679-019-0064-2
ASCI-D-18-00004.4Contact author: Dane Morgan </p
Characterization of exocellular DNA in the oligotrophic ocean
No full textApproximately half of the DNA in the open ocean is present outside of living cells. Together, this exocellular DNA (or dissolved DNA; D-DNA) is comprised of truly dissolved “free” DNA (F-DNA), virion encapsidated DNA, and DNA inside of membrane vesicles. It is ubiquitous in nature yet its sources, sinks, and ecological characteristics are largely unknown. One reason for the uncertainty is the methodological limitation that precludes a distinction among the three pools that comprise D-DNA. Using a novel method that provides complete separation of vesicles, viruses, and F-DNA, the first fully sequenced open ocean water-column profile of exocellular DNA was obtained. Euphotic zone F-DNA (75-125 m) contained mostly bacterial and viral sequences, with bacteria dominating in the mesopelagic zone (500-1000 m). A high proportion of mesopelagic zone (500 and 1000 m) F-DNA sequences appeared to originate from surface waters, including a large amount of DNA contributed by high-light Prochlorococcus ecotypes. These results indicate the composition of F-DNA in different regions of the water-column (euphotic and mesopelagic) and suggest potential mechanisms for dissolved organic matter cycling and export. Experiments designed to examine the dynamics of F-DNA suggest that it is produced by viral lysis of microbial cells, and may be consumed by heterotrophic bacteria and protists. Collectively, this research provides novel insights into the microbial origins and dynamics of F-DNA in the open ocean.Ph.D
Author Co-Citation Analysis (ACA): a powerful tool for representing implicit knowledge of scholar knowledge workers
No full textIn the last decade, knowledge has emerged as one of the most important and valuable organizational assets. Gradually this importance caused to emergence of new discipline entitled ―knowledge management‖. However one of the major challenges of knowledge management is conversion implicit or tacit knowledge to explicit knowledge. Thus Making knowledge visible so that it can be better accessed, discussed, valued or generally managed is a long-standing objective in knowledge management. Accordingly in this paper author co- citation analysis (ACA) will be proposed as an efficient technique of knowledge visualization in academia (Scholar knowledge workers)
Author Correction: Environmental variability supports chimpanzee behavioural diversity
No full textThe original version of the Supplementary Information associated with this Article included an incorrect Supplementary Data 1 file, in which three columns (L, M and P) had slightly different variable names from those written in the code. The HTML has been updated to include a corrected version of Supplementary Data 1; the correct version of Supplementary Data 1 can be found as Supplementary Information associated with this Correction.Additional co-authors: Mattia Bessone, Gregory Brazzola, Valentine Ebua Buh, Rebecca Chancellor, Heather Cohen, Charlotte Coupland, Bryan Curran, Emmanuel Danquah, Tobias Deschner, Dervla Dowd, Manasseh Eno-Nku, J. Michael Fay, Annemarie Goedmakers, Anne-Céline Granjon, Josephine Head, Daniela Hedwig, Veerle Hermans, Sorrel Jones, Jessica Junker, Parag Kadam, Mohamed Kambi, Ivonne Kienast, Deo Kujirakwinja, Kevin E. Langergraber, Juan Lapuente, Bradley Larson, Kevin C. Lee, Vera Leinert, Manuel Llana, Sergio Marrocoli, Amelia C. Meier, David Morgan, Emily Neil, Sonia Nicholl, Emmanuelle Normand, Lucy Jayne Ormsby, Liliana Pacheco, Alex Piel, Jodie Preece, Martha M. Robbins, Aaron Rundus, Crickette Sanz, Volker Sommer, Fiona Stewart, Nikki Tagg, Claudio Tennie, Virginie Vergnes, Adam Welsh, Erin G. Wessling, Jacob Willie, Roman M. Wittig, Yisa Ginath Yuh, Klaus Zuberbühler & Hjalmar S. Küh
Large igneous provinces and Earth’s carbon cycle: lessons from the late Triassic and rapidly emplaced Central Atlantic Magmatic Province
No full textUsing stable carbon isotopes of soil carbonates, I demonstrate that the eruption of the Central Atlantic Magmatic Province (CAMP) resulted in a transient perturbation of atmospheric pCO2 in the Late Triassic. I show evidence of a discrete pCO2 pulse (roughly a doubling) immediately after the first CAMP flow-unit preserved in the Newark rift basin, followed by a ~200 kyr falloff toward pre-eruptive concentrations, a pattern repeated above the second and third flow-units. Observations from the Hartford basin indicate that pCO2 had fallen to concentrations well below background by 400 kyr after the final eruptions in the earliest Jurassic. I use a simple geochemical model to demonstrate that this decrease below pre-eruptive background is most easily accomplished by the extrusion of ~1.12 x 107 km2 of basalt into the equatorial humid belt, which effectively amplified the increase in global continental weathering rate by perhaps as much as 50%. These results indicate that LIPs can be overall net sinks for CO2. A test of the Late Triassic equilibrium state from a 33-My record of pCO2 broadly shows a ~3-fold decrease from the Carnian through the Rhaetian. This pCO2 decrease is most consistent with the hypothesis that a Late-Triassic increase in continental area within the tropical humid belt, as a result of the slow northward migration of the Pangean Supercontinent, lead to increased rates of continental weathering and CO2 consumption. A significant implication of this finding is that changes in degassing rate from variable ocean crust production are not driving the long-term decrease in pCO2 because crustal production rates show little variability through the Late Triassic. Together, the results of this work lay the foundation for a revision of our understanding regarding the driving mechanisms behind Earth’s long-term carbon cycle toward a greater emphasis on weathering processes.Ph. D.Includes bibliographical referencesIncludes vitaby Morgan Frederick Schalle
The Dutch barrier our's : or, The interest of England and Holland inseparable. With reflections on the insolent treatment the Emperor and States-general have met with from the author of The conduct, and his brethren. To which is added, an enquiry into the causes of the clamour against the Dutch, particularly with reference to the fishery.
No full textSignatures: [pi]¹ A-D⁴ E³.Title within double line border.Teerink and Morgan both attribute this to John Oldmixon.In answer to Swift's The conduct of the Allies.TeerinkMorganMode of access: Internet
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