Now showing items 6014-6033 of 18256

    • Following the Behavior of the Flagellar Rotary Motor Near Zero Load 

      Yuan, Junying; Berg, Howard (Springer Verlag, 2009)
      At room temperature at stall, the flagellar motor of the bacterium Escherichia coli exerts a torque of ~1300 pN nm. At zero external load, it spins ~330 Hz. Techniques for studying the motor near zero load are novel and ...
    • Following the flow: tracer particles in astrophysical fluid simulations 

      Genel, Shy; Vogelsberger, Mark; Nelson, Dylan; Sijacki, Debora; Springel, Volker; Hernquist, Lars (Oxford University Press, 2013)
      We present two numerical schemes for passive tracer particles in the hydrodynamical moving-mesh code arepo, and compare their performance for various problems, from simple set-ups to cosmological simulations. The purpose ...
    • Following young people with perinatal HIV infection from adolescence into adulthood: the protocol for PHACS AMP Up, a prospective cohort study 

      Tassiopoulos, Katherine; Patel, Kunjal; Alperen, Julie; Kacanek, Deborah; Ellis, Angela; Berman, Claire; Allison, Susannah M; Hazra, Rohan; Barr, Emily; Cantos, Krystal; Siminski, Suzanne; Massagli, Michael; Bauermeister, Jose; Siddiqui, Danish Q; Puga, Ana; Van Dyke, Russell; Seage, George R (BMJ Publishing Group, 2016)
      Introduction: The first generation of adolescents born with HIV infection has reached young adulthood due to advances in treatment. It is important to continue follow-up of these individuals to assess their long-term ...
    • The Fontaine-Mazur conjecture for {GL}_2 

      Kisin, Mark (American Mathematical Society (AMS), 2009)
      We prove new cases of the Fontaine-Mazur conjecture, that a 2 -dimensional p -adic representation rho of G_{{Q}, S} which is potentially semi-stable at p with distinct Hodge-Tate weights arises from a twist of a modular ...
    • Food for Early Animal Evolution 

      Knoll, Andrew (Springer Nature, 2017-08)
      Ever since microorganisms first emerged, Earth and the life upon it have engaged in something of a pas de deux. Seldom during this long history have the dance's tempo and the dramatic heights of the jeté leaps exceeded ...
    • Food-Web Models Predict Species Abundances in Response to Habitat Change 

      Gotelli, Nicholas J; Ellison, Aaron M. (Public Library of Science, 2006)
      Plant and animal population sizes inevitably change following habitat loss, but the mechanisms underlying these changes are poorly understood. We experimentally altered habitat volume and eliminated top trophic levels of ...
    • Foot Callus Thickness Does Not Trade Off Protection for Tactile Sensitivity During Walking 

      Holowka, Nicholas; Wynands, Bert; Drechsel, Tina; Yegian, Andrew; Tobolsky, Victoria; Okutoyi, Paul; Mang’eni Ojiambo, Robert; Halle, Diresibachew; Sigel, Timothy; Zippenfennig, Claudio; Milani, Thomas; Lieberman, Daniel (Springer Science and Business Media LLC, 2019-06-26)
      Until relatively recently, humans, like other animals, were habitually barefoot, hence the soles of our feet were the only direct contact between the body and the ground when walking. There is indirect evidence that simple ...
    • Foot-propelled swimming kinematics and turning strategies in common loons 

      Clifton, Glenna T.; Biewener, Andrew (The Company of Biologists, 2018-08-20)
      Loons (Gaviiformes) are arguably one of the most successful groups of swimming birds. As specialist foot-propelled swimmers, loons are capable of diving up to 70 meters, remaining underwater for several minutes, and capturing ...
    • Footprints reveal direct evidence of group behavior and locomotion in Homo erectus 

      Hatala, Kevin G.; Roach, Neil T.; Ostrofsky, Kelly R.; Wunderlich, Roshna E.; Dingwall, Heather L.; Villmoare, Brian A.; Green, David J.; Harris, John W. K.; Braun, David R.; Richmond, Brian G. (Nature Publishing Group, 2016)
      Bipedalism is a defining feature of the human lineage. Despite evidence that walking on two feet dates back 6–7 Ma, reconstructing hominin gait evolution is complicated by a sparse fossil record and challenges in inferring ...
    • For a cognitive neuroscience of concepts: Moving beyond the grounding issue 

      Leshinskaya, Anna; Caramazza, Alfonso (Springer Verlag, 2016)
      Cognitive neuroscience research on conceptual knowledge often is discussed with respect to "embodiment" or "grounding." We tried to disentangle at least three distinct claims made using these terms. One of these, the view ...
    • For a Poetics of Social Life 

      Herzfeld, Michael (1987)
      One of the burning issues in modern anthropology concerns the relationship between the individual and the larger society. Is society a kind of metallic grid that we all have to move through in lockstep? How many of us feel ...
    • For Prayer and Profit: West Africa's Religious and Economic Ties to the Gulf 1960s to the Present 

      Akyeampong, Emmanuel K. (African Finance and Economic Association, 2010)
      West Africa’s historic ties of trade and Islam with the Arabian Peninsula date back to the 7th and 8th Centuries CE. On independence from colonial rule several African countries turned to the Arab world for official ...
    • For the Law, Neuroscience Changes Nothing and Everything 

      Greene, Joshua; Cohen, Jonathan D. (The Royal Society, 2004)
      The rapidly growing field of cognitive neuroscience holds the promise of explaining the operations of the mind in terms of the physical operations of the brain. Some suggest that our emerging understanding of the physical ...
    • For-Profit Colleges 

      Deming, David James; Goldin, Claudia D.; Katz, Lawrence F. (Brookings Institution Press, 2013)
      For-profit, or proprietary, colleges are the fastest-growing postsecondary schools in the nation, enrolling a disproportionately high share of disadvantaged and minority students and those ill-prepared for college. Because ...
    • Foraging strategies and diet composition of Hadza children 

      Crittenden, Alyssa N.; Conklin-Brittain, Nancy L.; Marlowe, Frank W.; Schoeninger, Margaret J.; Wrangham, Richard (John Wiley & Sons, 2009)
      Among the Hazda hunter-gatherers of Tanzania, children are active foragers and collect various types of wild plant foods and hunt small sized prey animals. The collection effort of Hazda children is reported to have a ...
    • Force and stroke of a hydrogel actuator 

      Illeperuma, Widusha Ruwangi Kaushalya; Sun, Jeong-Yun; Suo, Zhigang; Vlassak, Joost J. (Royal Society of Chemistry (RSC), 2013)
      Hydrogels that undergo a volume phase transition in response to an external stimulus are of great interest because of their possible use as actuator materials. The performance of an actuator material is normally characterized ...
    • Force and Velocity of Mycoplasma mobile Gliding 

      Miyata, Makoto; Ryu, William S.; Berg, Howard C. (American Society for Microbiology, 2002)
      The effects of temperature and force on the gliding speed of Mycoplasma mobile were examined. Gliding speed increased linearly as a function of temperature from 0.46 mum/s at 11.5degreesC to 4.0 mum/s at 36.5degreesC. A ...
    • Force control of flexible catheter robots for beating heart surgery 

      Kesner, Samuel Benjamin; Howe, Robert D. (Institute of Electrical and Electronics Engineers, 2011)
      Recent developments in cardiac catheter technology promise to allow physicians to perform most cardiac interventions without stopping the heart or opening the chest. However, current cardiac devices, including newly developed ...
    • Force fluctuations and polymerization dynamics of intracellular microtubules 

      Brangwynne, Clifford P.; MacKintosh, F. C.; Weitz, David A. (National Academy of Sciences, 2007)
      Microtubules are highly dynamic biopolymer filaments involved in a wide variety of biological processes including cell division, migration, and intracellular transport. Microtubules are very rigid and form a stiff structural ...