2,615 research outputs found

    Tributes to Professor Cyril A. Fox, Jr.

    Get PDF
    Cy Fox often forgets that he was supposed to be “only” an academic. For three decades, as he helped thousands of law students through the intricacies of the Rule in Shelley’s Case, or watched them calculate a “life in being plus twenty one years” for the Rule Against Perpetuities, he failed to appreciate that law school was supposed to be an amalgam of theory and confusion, not the place for his teaching law students about helping real people solve real life problems

    Computational study of T cell repolarization during target elimination

    Get PDF
    T Cells are one of the most important players of the immune system. They are responsible for the elimination of the pathogen-infected or tumorigenic cells (target cells). When a target cell is recognized, the T Cell establishes a contact zone called the immunological synapse (IS). Subsequently, the cytoskeleton rotates and the MTOC relocates to the IS. The cytoskeleton rotation is correlated with a movement of organelles attached to microtubules (MT). The MTOC repositioning results from an interplay between MTs and dyneins in the IS pulling MTs via two mechanisms: cortical sliding and capture-shrinkage. Since many aspects of the process remain unknown, we designed a theoretical model for the molecular-motor-driven motion of the MT cytoskeleton in the cell with one or two IS. The model offers explanations of several experimental results including the biphasic nature of the MTOC movement. We also compared the two mechanisms in different cell configurations and found that the T Cell performs one of the most important immune reactions with stunning efficiency by the advantageous placement of dyneins and by employing two mechanisms acting in synergy. We also analyzed Ca2+ diffusion in the T Cell following the MTOC repositioning. We provided the evidence that mitochondria relocate towards the IS with the MTOC and their placement together with their ability of absorption and redistribution significantly increase the Ca2+ concentration.T Zellen sind einer der wichtigsten Spieler des Immunsystems. Sie sind verantwortlich für die Beseitigung von infizierten-oder tumorösen Zellen (Zielzellen). Wenn eine Zielzelle erkannt ist, schafft die T-Zelle eine Immunologische Synapse (IS) genannte Kontaktzone. Dann rotiert das Zytoskelett und das MTOC zieht zur IS. Die Rotation ist mit einer Bewegung von an Mikrotubuli (MT) angehefteten Organellen korreliert. Die MOTC Umpositionierung ergibt sich aus dem Zusammenspiel zwischen MT und Dyneinen in der IS wobei MTs über zwei Mechanismen gezogen werden: ”cortical slidingünd ”captureshrinkage”. Da viele Aspekte des Prozesses unbekannt bleiben entwarfen wir ein theoretisches Modell für die durch molekulare Dyneinen Bewegung des MT Zytoskeletts in der Zelle mit einer oder zwei IS. Das Modell bietet Erklärungen mehrerer experimenteller Ergebnisse einschließlich der biphasischen Natur der MTOC Bewebung. Ebenso verglichen wir die beiden Mechanismen unter verschiedenen Konfigurationen und fanden, dass die T-Zelle eine der wichtigsten Immunreaktionen durch nutzbar Anordnung von Dyneinen und Einsatzes zweier in Synergie arbeitenden Mechanismen mit erstaunlicher Effizienz durchführt. Wir analysierten auch folgenden Ca2+ Diffusion in der T-Zelle. Wir liefern den Nachweis, dass Mitochondrien mit das MTOC zu der IS ziehen und ihre Plazierung, zusammen mit der Fähigkeit der Absorption und Umverteilung, die global Ca2+ Konzentration signifikant steiger

    The use of think-alouds in order to increase comprehension in struggling readers at the middle school level

    Get PDF
    This study assessed the effect that the use of the think-aloud strategy had on improving reading comprehension of struggling middle school readers. The study consisted of a six-week intervention in which the student were provided instruction in the use of the think-aloud strategy three days each week during their small-group reading class. Seven students, four boys and three girls, from an urban, public school near Milwaukee, Wisconsin, participated in this study. The researcher used marked think-aloud passages from the Qualitative Reading Inventory-V (Leslie & Caldwell, 2010), the Fountas and Pinnell reading assessment, and MAPs (Measures of Academic Progress) in order to obtain data before the onset of the study and at the end of the study in order to gauge its effectiveness. Additionally, the researcher monitored progress through the use of guided and independent practice on the use of think-alouds on high-interest reading passages. Data findings indicated that the treatment had a positive impact on the students\u27 ability to answer explicit comprehension questions. The study did not positively impact the students\u27 ability to answer implicit questions. Teachers who are considering using the think-aloud strategy should consider examining this study

    Media Consolidation & Political Polarization: Reviewing the National Television Ownership Rule

    Get PDF
    Local television plays an important role in the democratic society. The medium is viewed as being trustworthy, and it is accessible and uniquely situated to report on matters of local interest. Among other roles, the Federal Communications Commission (FCC) regulates firms’ ownership interests in the media through regulations that permit a certain degree of consolidation at both the local and national levels. Since 1996, Congress has mandated that the FCC regularly review broadcast media ownership regulations. Originally, this requirement mandated biennial review. In 2004, however, Congress revised the mandate, requiring review on a quadrennial basis and excluding from such review only the regulation limiting broadcast television firms’ ownership interests at the national level—the national television ownership rule. Since then, permissive regulations and the financial state of the local broadcast television industry have promoted consolidation among firms, and commentary suggests this consolidation has contributed to political polarization. A case study of the impact of one firm’s acquisition of affiliates demonstrates the relationship between consolidation and polarization, while the firm’s recent attempted acquisition demonstrates the stakes of the transactions the national television ownership rule currently permits. Balancing First Amendment guarantees viewed in light of the “marketplace of ideas” metaphor with concerns raised by commentary identifying a link between consolidation and political polarization, this Note asserts that the regulations governing national limits on broadcast television ownership should be subject to regular review alongside other broadcast media regulations, beginning with the FCC’s next quadrennial review. Beyond this recommendation, this Note proposes moderate amendments to the rule and presents additional mitigating measures that could alternatively address the policy concerns underlying this Note’s proposals

    Every coin has a back side: Invasion by Limnohabitans planktonicus promotes the maintenance of species diversity in bacterial communities

    Get PDF
    One of the earliest challenges for ecologists has been to study the impact of invasive species on microbial communities. Although bacteria are fundamental in biological processes, current knowledge on invasion effects by aquatic nonpathogenic bacteria is still limited. Using pure cultures of diverse planktonic bacteria as model organisms at two different carbon concentration levels, we tested the response of an assembled community to the invasion by Limnohabitans planktonicus, an opportunistic bacterium, successful in freshwaters. The invader, introduced at the early stationary growth phase of the resident community, caused a strong decrement of the abundance of the dominant species. This was due to competition for nutrients and a potential allelopathic interaction. Simultaneously, resident species formerly unable to successfully compete within the community, thus potentially exposed to competitive exclusion, increased their abundances. The overall result of the invasion was preservation of species diversity, the higher the lower was the substrate content available. Our study provides new insights into bacterial invasions, offering an alternative interpretation of invasions for community ecology

    Characterization of RNA aptamer binding to Rift Valley fever virus nucleocapsid protein

    Get PDF
    Rift Valley fever virus (RVFV) is a mosquito-borne virus that can cause hemorrhagic fever in humans and miscarriage in livestock. There is currently no cure for RVFV. Viral nucleocapsid protein (N) binding to viral RNA is crucial for RVFV replication, transcription, and genome protection. If N-RNA binding is prevented, RVFV will be unable to propagate in a host. This suggests that disruption of N-RNA interaction is a good potential therapeutic strategy for a new class of antiviral drugs. To exploit this target, molecular details about how N recognizes its preferred RNA binding sites must be elucidated. The Lodmell laboratory previously discovered a small RNA shown to bind N with high affinity called MBE87. MBE87 structure contains two GAUU nucleotide motifs. We have collaborated with Dr. Doug Raiford in the Computer Science department at UM to design RNAs with the same predicted secondary structure as MBE87 but with GAUU motifs at different positions in the structure. We hypothesize that the position of the GAUU motif is important for recognition by N and thus for viral functions. Using MBE87 and an RNA devoid of GAUU motifs as controls, electrophoretic mobility shift assays were performed to determine if moving the GAUU sequence affects N-RNA binding affinity. We performed the binding experiments in the presence and absence of suramin, a drug recently shown to inhibit RVFV replication. Our results suggest that suramin acts as a competitive inhibitor that binds to the site on N where aptamer RNA also binds. Because suramin binds at a site that at least overlaps with the aptamer RNA binding site, it had a stronger inhibitory effect on weaker-binding aptamers. When completed, this research will lend insight into how N recognizes preferred viral or host RNA binding sites and will pave the way toward development of drugs that target N protein
    • …
    corecore