Flow directionality of pristine meandering rivers is embedded in the skewing of high-amplitude bends and neck cutoffs.

abstract：:We solve a discrete version of the classic Plateau problem, which asks for a minimal surface spanning a given curve. Our algorithm is based on a network-flow formulation that finds minimal slabs, intuitively corresponding to minimal "surfaces" of prescribed thickness. We let the slab thickness approach zero in order t...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Hu TC,Kahng AB,Robins G

更新日期：1992-10-01 00:00:00

abstract：:Junctions that mediate excitation-contraction (e-c) coupling are formed between the sarcoplasmic reticulum (SR) and either the surface membrane or the transverse (T) tubules in normal skeletal muscle. Two structural components of the junctions, the feet of the SR and the tetrads of T tubules, have been identified resp...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Takekura H,Nishi M,Noda T,Takeshima H,Franzini-Armstrong C

更新日期：1995-04-11 00:00:00

abstract：:How did language evolve? A popular approach points to the similarities between the ontogeny and phylogeny of language. Young children's language and nonhuman primates' signing both appear formulaic with limited syntactic combinations, thereby suggesting a degree of continuity in their cognitive abilities. To evaluate ...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Yang C

更新日期：2013-04-16 00:00:00

abstract：:Detection and avoidance of impending obstacles is crucial to preventing head and body injuries in daily life. To safely avoid obstacles, locations of objects approaching the body surface are usually detected via the visual system and then used by the motor system to guide defensive movements. Mediating between visual ...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Huang RS,Chen CF,Tran AT,Holstein KL,Sereno MI

更新日期：2012-10-30 00:00:00

abstract：:To permit rapid optical control of brain activity, we have engineered multiple lines of transgenic mice that express the light-activated cation channel Channelrhodopsin-2 (ChR2) in subsets of neurons. Illumination of ChR2-positive neurons in brain slices produced photocurrents that generated action potentials within m...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Wang H,Peca J,Matsuzaki M,Matsuzaki K,Noguchi J,Qiu L,Wang D,Zhang F,Boyden E,Deisseroth K,Kasai H,Hall WC,Feng G,Augustine GJ

更新日期：2007-05-08 00:00:00

abstract：:Microtubule assembly is enhanced by the addition of 1 M sucrose or 4 M glycerol to the reassembly mixture. Tubulin can be purified from guinea pig brain readily and in good yield by two cycles of assembly in glycerol-containing solutions. The tubules assembled in glycerol and sucrose are more stable than tubules forme...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Shelanski ML,Gaskin F,Cantor CR

更新日期：1973-03-01 00:00:00

abstract：:We developed a helper-dependent adenoviral vector for cystic fibrosis lung gene therapy. The vector expresses cystic fibrosis transmembrane conductance regulator (Cftr) using control elements from cytokeratin 18. The vector expressed properly localized CFTR in cultured cells and in the airway epithelia of mice. Cftr R...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Koehler DR,Sajjan U,Chow YH,Martin B,Kent G,Tanswell AK,McKerlie C,Forstner JF,Hu J

更新日期：2003-12-23 00:00:00

abstract：:In organisms possessing a dispersal phase the processes of mating, competition, feeding, and predation are often carried out within "trait-groups," defined as populations enclosed in areas smaller than the boundaries of the deme. A simple model shows that this can lead to the selection of "altruistic" traits that favo...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Wilson DS

更新日期：1975-01-01 00:00:00

abstract：:Clustered DNA damage induced by ionizing radiation is refractory to repair and may trigger carcinogenic events for reasons that are not well understood. Here, we used an in situ method to directly monitor induction and repair of clustered DNA lesions in individual cells. We showed, consistent with biophysical modeling...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Asaithamby A,Hu B,Chen DJ

更新日期：2011-05-17 00:00:00

abstract：:During development, organisms acquire three-dimensional (3D) shapes with important physiological consequences. While basic mechanisms underlying morphogenesis are known in eukaryotes, it is often difficult to manipulate them in vivo. To circumvent this issue, here we present a study of developing Vibrio cholerae biofi...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Fei C,Mao S,Yan J,Alert R,Stone HA,Bassler BL,Wingreen NS,Košmrlj A

更新日期：2020-04-07 00:00:00

abstract：:Sparse 3T3 cells, in excess serum, become quiescent in the early G(1) (or G(0)) phase of the cell cycle if the cells are cultured in low concentrations of amino acids, glucose, or phosphate ion. These quiescent cells then initiate DNA synthesis if the concentration of the limiting nutrient is increased. In normal medi...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Holley RW,Kiernan JA

更新日期：1974-08-01 00:00:00

abstract：:The lentiviruses are associated with a wide range of chronic diseases in mammals. These include immunodeficiencies (such as HIV/AIDS in humans), malignancies, and lymphatic and neurological disorders in primates, felids, and a variety of wild and domesticated ungulates. Evolutionary analyses of the genomic sequences o...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Katzourakis A,Tristem M,Pybus OG,Gifford RJ

更新日期：2007-04-10 00:00:00

abstract：:Fluorescent bisretinoids, such as A2E and all-trans-retinal dimer, form as a by-product of vitamin A cycling in retina and accumulate in retinal pigment epithelial (RPE) cells as lipofuscin pigments. These pigments are implicated in pathological mechanisms involved in several vision-threatening diseases including age-...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Wu Y,Yanase E,Feng X,Siegel MM,Sparrow JR

更新日期：2010-04-20 00:00:00

abstract：:TNF family members and their receptors contribute to increased gene expression for inflammatory processes and intracellular cascades leading to programmed cell death, both via activation of NF-kappaB. TNF receptor (TNFR)-associated factors (TRAFs) are cytoplasmic adaptor proteins binding to various receptors of the TN...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Hauer J,Püschner S,Ramakrishnan P,Simon U,Bongers M,Federle C,Engelmann H

更新日期：2005-02-22 00:00:00

abstract：:In the face of antibiotics, bacterial populations avoid extinction by harboring a subpopulation of dormant cells that are largely drug insensitive. This phenomenon, termed "persistence," is a major obstacle for the treatment of a number of infectious diseases. The mechanism that generates both actively growing as well...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Rotem E,Loinger A,Ronin I,Levin-Reisman I,Gabay C,Shoresh N,Biham O,Balaban NQ

更新日期：2010-07-13 00:00:00

abstract：:Temporal integration in visual perception is thought to occur within cycles of occipital alpha-band (8-12 Hz) oscillations. Successive stimuli may be integrated when they fall within the same alpha cycle and segregated for different alpha cycles. Consequently, the speed of alpha oscillations correlates with the tempor...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Wutz A,Melcher D,Samaha J

更新日期：2018-02-06 00:00:00

abstract：:Human mitochondria contain their own genome, mitochondrial DNA, that is expressed in the mitochondrial matrix. This genome encodes 13 vital polypeptides that are components of the multisubunit complexes that couple oxidative phosphorylation (OXPHOS). The inner mitochondrial membrane that houses these complexes compris...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Zorkau M,Albus CA,Berlinguer-Palmini R,Chrzanowska-Lightowlers ZMA,Lightowlers RN

更新日期：2021-02-09 00:00:00

abstract：:Previous studies of legume nodules have indicated that formation of the heme moiety of leghemoglobin is a function of the bacterial symbiont. We now show that a hemA mutant of Bradyrhizobium japonicum that cannot carry out the first step in heme biosynthesis forms fully effective nodules on soybeans. The bacterial mut...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Guerinot ML,Chelm BK

更新日期：1986-03-01 00:00:00

abstract：:The synaptonemal complex (SC) is a conserved meiotic structure that regulates the repair of double-strand breaks (DSBs) into crossovers or gene conversions. The removal of any central-region SC component, such as the Drosophila melanogaster transverse filament protein C(3)G, causes a complete loss of SC structure and ...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Billmyre KK,Cahoon CK,Heenan GM,Wesley ER,Yu Z,Unruh JR,Takeo S,Hawley RS

更新日期：2019-10-22 00:00:00

abstract：:Genetic polymorphism in the H-2:Qa:Tla region of chromosome 17 is associated with constitutive variation of bodily odor phenotypes which permit individual olfactory recognition among mice. To determine whether known genes in the H-2:Qa:Tla complex are concerned in the constitution of odor phenotypes, mice were tested ...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Yamazaki K,Beauchamp GK,Egorov IK,Bard J,Thomas L,Boyse EA

更新日期：1983-09-01 00:00:00

abstract：:The highly productive coastal Mediterranean fishery off the Nile River delta collapsed after the completion of the Aswan High Dam in 1965. But the fishery has been recovering dramatically since the mid-1980s, coincident with large increases in fertilizer application and sewage discharge in Egypt. We use stable isotope...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Oczkowski AJ,Nixon SW,Granger SL,El-Sayed AF,McKinney RA

更新日期：2009-02-03 00:00:00

abstract：:Genetically engineered mice with targeted disruption of the neuronal nitric oxide synthase (nNOS) gene established the inhibitory role of nitric oxide (NO) in male impulsive aggressive behavior. This was later confirmed by using selective nNOS inhibitors in male wild-type mice. The molecular mechanisms accounting for ...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Chiavegatto S,Dawson VL,Mamounas LA,Koliatsos VE,Dawson TM,Nelson RJ

更新日期：2001-01-30 00:00:00

abstract：:A method is described in which the interference of radiated second-harmonic electric fields generated by a pair of oriented molecules intercalated into double-stranded DNA is controlled and measured. The results show that the relative molecular orientation of the two molecules significantly changes the magnitude of th...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Doughty B,Rao Y,Kazer SW,Kwok SJ,Turro NJ,Eisenthal KB

更新日期：2013-04-09 00:00:00

abstract：:The mosquito midgut plays a central role in the sporogonic development of malaria parasites. We have found that polyclonal sera, produced against mosquito midguts, blocked the passage of Plasmodium falciparum ookinetes across the midgut, leading to a significant reduction of infections in mosquitoes. Anti-midgut mAbs ...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Lal AA,Patterson PS,Sacci JB,Vaughan JA,Paul C,Collins WE,Wirtz RA,Azad AF

更新日期：2001-04-24 00:00:00

abstract：:Activation of the syk tyrosine kinase occurs almost immediately following engagement of many types of antigen receptors, including Fc receptors, but the mechanism through which syk is activated is currently unclear. Here we demonstrate that Fc receptor-induced syk activation occurs as the result of phosphorylation of ...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： El-Hillal O,Kurosaki T,Yamamura H,Kinet JP,Scharenberg AM

更新日期：1997-03-04 00:00:00

abstract：:The origin of the two-phase (cap, no cap) macroscopic kinetic model of the end of a microtubule is reviewed. The model is then applied to a new theoretical problem, namely, the Mitchison-Kirschner [Mitchison, T. & Kirschner, M. W. (1984) Nature (London) 312, 237-242] experiment in which aggregated microtubules in solu...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Chen Y,Hill TL

更新日期：1985-06-01 00:00:00

abstract：:The adenoviral E1A oncogene sensitizes mammalian cells to tumor necrosis factor-alpha (TNF-alpha), in part by repressing the nuclear factor-kappa B (NF-kappa B)-dependent defense against this cytokine. Other E1A activities involve binding to either p300/cyclic AMP response element-binding protein (CBP) or retinoblasto...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Cook JL,Walker TA,Worthen GS,Radke JR

更新日期：2002-07-23 00:00:00

abstract：:Among the earliest and most important stages during tumorigenesis is the activation of the angiogenic process, an event that is termed the "switch to the angiogenic phenotype." We have developed an in vivo system that can reliably recapitulate the stages in tumor development that represent this transition. Using this ...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Fang J,Shing Y,Wiederschain D,Yan L,Butterfield C,Jackson G,Harper J,Tamvakopoulos G,Moses MA

更新日期：2000-04-11 00:00:00

abstract：:Bacterial outer membrane porins have a robust beta-barrel structure and therefore show potential for use as stochastic sensors based on single-molecule detection. The monomeric porin OmpG is especially attractive compared with multisubunit proteins because appropriate modifications of the pore can be easily achieved b...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Chen M,Khalid S,Sansom MS,Bayley H

更新日期：2008-04-29 00:00:00

abstract：:Remembering and discriminating objects based on their previously learned values are essential for goal-directed behaviors. While the cerebral cortex is known to contribute to object recognition, surprisingly little is known about its role in retaining long-term object-value associations. To address this question, we t...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Ghazizadeh A,Griggs W,Leopold DA,Hikosaka O

更新日期：2018-02-27 00:00:00