Fundamental differences between Arctic and Antarctic ozone depletion.

abstract：:The supposition that agricultural intensification results in land sparing for conservation has become central to policy formulations across the tropics. However, underlying assumptions remain uncertain and have been little explored in the context of conservation incentive schemes such as policies for Reducing Emission...

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

authors： Phelps J,Carrasco LR,Webb EL,Koh LP,Pascual U

更新日期：2013-05-07 00:00:00

abstract：:Prolonged incubation of NIH 3T3 cells under the growth constraint of confluence results in the death of some cells in a manner suggestive of apoptosis. Successive rounds of prolonged incubation at confluence of the surviving cells produce increasing neoplastic transformation in the form of increments in saturation den...

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

authors： Rubin H,Yao A,Chow M

更新日期：1995-05-23 00:00:00

abstract：:Most climate models are large dynamical systems involving a million (or more) variables on big computers. Given that they are nonlinear and not perfect, what can we expect to learn from them about the earth's climate? How can we determine which aspects of their output might be useful and which are noise? And how shoul...

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

authors： Smith LA

更新日期：2002-02-19 00:00:00

abstract：:Vertebrate remains recovered from a limestone fissure filling on Antigua, Lesser Antilles, are associated with radiocarbon dates ranging from 4300 to 2500 yr B.P., contemporaneous with the earliest aboriginal human occupation of the island. Nine taxa of lizards, snakes, birds, bats, and rodents (one-third of the total...

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

authors： Steadman DW,Pregill GK,Olson SL

更新日期：1984-07-01 00:00:00

abstract：:Control of iron homeostasis is essential for healthy central nervous system function: iron deficiency is associated with cognitive impairment, yet iron overload is thought to promote neurodegenerative diseases. Specific genetic markers have been previously identified that influence levels of transferrin, the protein t...

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

authors： Jahanshad N,Kohannim O,Hibar DP,Stein JL,McMahon KL,de Zubicaray GI,Medland SE,Montgomery GW,Whitfield JB,Martin NG,Wright MJ,Toga AW,Thompson PM

更新日期：2012-04-03 00:00:00

abstract：:Cell couples have been formed by mixing an antigen- and Ia-specific cloned helper T-cell line with a B-cell hybridoma presenting the antigen. By immunofluorescence observations, we have shown that the microtubule-organizing center (MTOC) inside the helper T cell, but not in the bound antigen-presenting cell, becomes o...

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

authors： Kupfer A,Swain SL,Janeway CA Jr,Singer SJ

更新日期：1986-08-01 00:00:00

abstract：:Loss of miR-15/16 is the most common genetic lesion in chronic lymphocytic leukemia (CLL), promoting overexpression of BCL2, which factors in leukemia pathogenesis. Indeed, an inhibitor of Bcl2, venetoclcax, is highly active in the treatment of patients with CLL. However, single-agent venetoclcax fails to eradicate mi...

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

authors： Rassenti LZ,Balatti V,Ghia EM,Palamarchuk A,Tomasello L,Fadda P,Pekarsky Y,Widhopf GF 2nd,Kipps TJ,Croce CM

更新日期：2017-10-03 00:00:00

abstract：:The early reactions in the catabolism of quinic acid in Neurospora crassa are controlled by at least four genes which are clustered on linkage group VII. Three of the loci (qa-2, qa-4, and qa-3) encode enzymes that convert quinic acid to protocatechuic acid. The fourth gene (qa-1) encodes a positive regulatory protein...

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

authors： Schweizer M,Case ME,Dykstra CC,Giles NH,Kushner SR

更新日期：1981-08-01 00:00:00

abstract：:The antitumor drug Taxol stabilizes microtubules and reduces their dynamicity, promoting mitotic arrest and cell death. Upon assembly of the alpha/beta-tubulin heterodimer, GTP bound to beta-tubulin is hydrolyzed to GDP reaching a steady-state equilibrium between free tubulin dimers and microtubules. The binding of Ta...

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

authors： Xiao H,Verdier-Pinard P,Fernandez-Fuentes N,Burd B,Angeletti R,Fiser A,Horwitz SB,Orr GA

更新日期：2006-07-05 00:00:00

abstract：:The complement system is highly efficient in targeting pathogens, but lack of its apposite regulation results in host-cell damage, which is linked to diseases. Thus, complement activation is tightly regulated by a series of proteins, which primarily belong to the regulators of complement activation (RCA) family. Struc...

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

authors： Panwar HS,Ojha H,Ghosh P,Barage SH,Raut S,Sahu A

更新日期：2019-05-14 00:00:00

abstract：:The role of ornithine decarboxylase (OrnDCase, EC 4.1.1.17) and of the polyamines [putrescine (Put), spermidine (Spd), and spermine (Spm)] in mouse skin tumor promotion was investigated by the use of alpha-difluoromethylornithine (CHF2-Orn), an enzyme-activated irreversible inhibitor of OrnDCase. 12-O-Tetradecanoylpho...

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

authors： Weeks CE,Herrmann AL,Nelson FR,Slaga TJ

更新日期：1982-10-01 00:00:00

abstract：:2'-Deoxyadenosine 5'-O-(1-thiotriphosphate) (dATP[alpha S]) was introduced into the 3' ends of DNA restriction fragments with Escherichia coli DNA polymerase I to give phosphorothioate internucleotide linkages. Such "capped" 3' ends were found to be resistant to exonuclease III digestion. Moreover, the resistance to d...

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

authors： Putney SD,Benkovic SJ,Schimmel PR

更新日期：1981-12-01 00:00:00

abstract：:We demonstrate remote detection of nuclear magnetic resonance (NMR) with a microchip sensor consisting of a microfluidic channel and a microfabricated vapor cell (the heart of an atomic magnetometer). Detection occurs at zero magnetic field, which allows operation of the magnetometer in the spin-exchange relaxation-fr...

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

authors： Ledbetter MP,Savukov IM,Budker D,Shah V,Knappe S,Kitching J,Michalak DJ,Xu S,Pines A

更新日期：2008-02-19 00:00:00

abstract：:By optically probing with a focused, low-power laser beam, we measured the spontaneous deflection fluctuations of the sensory hair bundles on frog saccular hair cells with a sensitivity of about 1 pm/square root of Hz. The preparation was illuminated by two orthogonally polarized laser beams separated by only about 0....

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

authors： Denk W,Webb WW,Hudspeth AJ

更新日期：1989-07-01 00:00:00

abstract：:Amputation of the zebrafish caudal fin stimulates regeneration of the dermal skeleton and reexpression of sonic hedgehog (shh)-signaling pathway genes. Expression patterns suggest a role for shh signaling in the secretion and patterning of the regenerating dermal bone, but a direct role has not been demonstrated. We e...

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

authors： Quint E,Smith A,Avaron F,Laforest L,Miles J,Gaffield W,Akimenko MA

更新日期：2002-06-25 00:00:00

abstract：:Copper is an essential metal nutrient that is tightly regulated in the body because loss of its homeostasis is connected to severe diseases such as Menkes and Wilson diseases, Alzheimer's disease, prion disorders, and amyotrophic lateral sclerosis. The complex relationships between copper status and various stages of ...

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

authors： Hirayama T,Van de Bittner GC,Gray LW,Lutsenko S,Chang CJ

更新日期：2012-02-14 00:00:00

abstract：:We have cloned a murine cDNA encoding a tyrosine kinase receptor with about 90% similarity to the chicken fibroblast growth factor (FGF) receptor and the human fms-like gene (FLG) tyrosine kinase. This mouse receptor lacks 88 amino acids in the extracellular portion, leaving only two immunoglobulin-like domains compar...

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

authors： Mansukhani A,Moscatelli D,Talarico D,Levytska V,Basilico C

更新日期：1990-06-01 00:00:00

abstract：:The G-protein-coupled metabotropic glutamate receptor mGluR1 alpha and the ionotropic glutamate receptor GluR6 were examined for posttranslational palmitoylation. Recombinant receptors were expressed in baculovirus-infected insect cells or in human embryonic kidney cells and were metabolically labeled with [3H]palmiti...

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

authors： Pickering DS,Taverna FA,Salter MW,Hampson DR

更新日期：1995-12-19 00:00:00

abstract：:Agrobacterium tumefaciens harboring the tumor-inducing Ti plasmid incites crown gall tumor on dicotyledonous species. Upon infection of these plants, Ti plasmid DNA sequence is stably transferred (T-DNA) by unknown mechanisms to plant cells to be integrated into nuclear DNA. The T-DNA processing and transfer require t...

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

authors： Usami S,Okamoto S,Takebe I,Machida Y

更新日期：1988-06-01 00:00:00

abstract：:A complementarity-determining region (CDR) of the mouse monoclonal antibody (mAb) F58 was constructed with specificity to a neutralization-inducing region of human immunodeficiency virus type 1 (HIV-1). The mAb has its major reactivity to the amino acid sequence I--GPGRA in the V3 viral envelope region. All CDRs inclu...

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

authors： Levi M,Sällberg M,Rudén U,Herlyn D,Maruyama H,Wigzell H,Marks J,Wahren B

更新日期：1993-05-15 00:00:00

abstract：:Membranes were purified from rat muscle by a differential centrifugation method that avoids the use of salt extraction or incubations at elevated temperature. Three populations of membrane-limited vesicles were defined having average densities of 1.112 (fraction I), 1.141 (fraction II), and 1.158 (fraction III) g/ml i...

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

authors： Barchi RL,Bonilla E,Wong M

更新日期：1977-01-01 00:00:00

abstract：:Interleukin (IL)-15 and its specific receptor chain, IL-15Rα, support the development of various effector cells, including NK and CD8 T cells via a mechanism called trans-presentation. Whereas the dynamic of trans-presentation has been shown to involve the recycling of IL-15Rα by presenting cells, the way responding c...

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

authors： Tamzalit F,Barbieux I,Plet A,Heim J,Nedellec S,Morisseau S,Jacques Y,Mortier E

更新日期：2014-06-10 00:00:00

abstract：:Ribonucleotide reductase provides deoxynucleotides for nuclear and mitochondrial (mt) DNA replication and repair. The mammalian enzyme consists of a catalytic (R1) and a radical-generating (R2 or p53R2) subunit. During S-phase, a R1/R2 complex is the major provider of deoxynucleotides. p53R2 is induced by p53 after DN...

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

authors： Pontarin G,Fijolek A,Pizzo P,Ferraro P,Rampazzo C,Pozzan T,Thelander L,Reichard PA,Bianchi V

更新日期：2008-11-18 00:00:00

abstract：:Although gamma frequency oscillations are common in the brain, their functional contributions to neural computation are not understood. Here we report in vitro electrophysiological recordings to evaluate how noisy gamma frequency oscillatory input interacts with the overall activation level of a neuron to determine th...

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

authors： Markowitz DA,Collman F,Brody CD,Hopfield JJ,Tank DW

更新日期：2008-06-17 00:00:00

abstract：:Exposures to ambient and household fine-particulate matter (PM2.5) together are among the largest single causes of premature mortality in India according to the Global Burden of Disease Studies (GBD). Several recent investigations have estimated that household emissions are the largest contributor to ambient PM2.5 exp...

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

authors： Chowdhury S,Dey S,Guttikunda S,Pillarisetti A,Smith KR,Di Girolamo L

更新日期：2019-05-28 00:00:00

abstract：:Some tumor cell lines secrete high concentrations of TGFbeta or IL-1. Similarly high concentrations of each of these cytokines cross-activate the other pathway: TGFbeta activates NFkappaB, and IL-1beta activates Smads. The IL-1 signaling components IRAK, MyD88, TRAF6, and TAK1 are all required for cross-activation of ...

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

authors： Lu T,Tian L,Han Y,Vogelbaum M,Stark GR

更新日期：2007-03-13 00:00:00

abstract：:Extracellular potassium concentration is actively maintained within narrow limits in all higher organisms. Slight variations in extracellular potassium levels can induce major alterations of essential physiological functions in excitable tissues. Here we describe that superfusion of cultured rat hippocampal neurones w...

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

authors： Pardo LA,Heinemann SH,Terlau H,Ludewig U,Lorra C,Pongs O,Stühmer W

更新日期：1992-03-15 00:00:00

abstract：:Recent studies show that plant organ positioning may be mediated by localized concentrations of the plant hormone auxin. Auxin patterning in the shoot apical meristem is in turn brought about by the subcellular polar distribution of the putative auxin efflux mediator, PIN1. However, the question of what signals determ...

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

authors： Jönsson H,Heisler MG,Shapiro BE,Meyerowitz EM,Mjolsness E

更新日期：2006-01-31 00:00:00

abstract：:Early conformational events during folding of acyl-CoA binding protein (ACBP), an 86-residue alpha-helical protein, were explored by using a continuous-flow mixing apparatus with a dead time of 70 micros to measure changes in intrinsic tryptophan fluorescence and tryptophan-dansyl fluorescence energy transfer. Althoug...

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

authors： Teilum K,Maki K,Kragelund BB,Poulsen FM,Roder H

更新日期：2002-07-23 00:00:00

abstract：:Septins assemble into filaments and higher-order structures that act as scaffolds for diverse cell functions including cytokinesis, cell polarity, and membrane remodeling. Despite their conserved role in cell organization, little is known about how septin filaments elongate and are knitted together into higher-order a...

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

authors： Bridges AA,Zhang H,Mehta SB,Occhipinti P,Tani T,Gladfelter AS

更新日期：2014-02-11 00:00:00