Fungal farming in a snail.

abstract：:The three-dimensional crystal structure of variant-3 toxin from the scorpion Centruroides sculpturatus Ewing has been determined at 3 A resolution. Phases were obtained by use of K2PtCl4 and K2IrCl6 derivatives. The most prominent secondary structural features are two and a half turns of alpha-helix and a three-strand...

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

authors： Fontecilla-Camps JC,Almassy RJ,Suddath FL,Watt DD,Bugg CE

更新日期：1980-11-01 00:00:00

abstract：:This work explores the concept that differential wave function overlap between excited states can be engineered within a molecular chromophore. The aim is to control excited state wave function symmetries, so that symmetry matches or mismatches result in differential orbital overlap and define low-energy trajectories ...

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

authors： Oviedo PS,Baraldo LM,Cadranel A

更新日期：2021-01-26 00:00:00

abstract：:Injection of 3':5'-cyclic AMP (cAMP) into larvae of the fly Sarcophaga bullata 3-4 hr before the beginning of puparium formation (red-spiracle stage) greatly accelerates the onset of tanning without affecting initiation of puparium formation (anterior retraction). Accelerated tanning resembles real tanning in two impo...

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

authors： Fraenkel G,Blechl A,Blechl J,Herman P,Seligman MI

更新日期：1977-05-01 00:00:00

abstract：:Broken-cell preparations of Salmonella typhimurium rapidly incorporated 75Se from 75SeO3(2-) into tRNA by an ATP-dependent process. Selenium incorporation in the presence of 50 microM 75SeO3(2-) (0.8-1 pmol per A260 unit) was enhanced by the selenocysteine precursor, O-acetyl-L-serine (to 3.7 pmol per A260 unit). This...

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

authors： Veres Z,Tsai L,Politino M,Stadtman TC

更新日期：1990-08-01 00:00:00

abstract：:The unprecedented scale of the Ebola outbreak in Western Africa (2014-2015) has prompted an explosion of efforts to understand the transmission dynamics of the virus and to analyze the performance of possible containment strategies. Models have focused primarily on the reproductive numbers of the disease that represen...

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

authors： Lau MS,Dalziel BD,Funk S,McClelland A,Tiffany A,Riley S,Metcalf CJ,Grenfell BT

更新日期：2017-02-28 00:00:00

abstract：:Small molecules that specifically bind with high affinity to any designated DNA sequence in the human genome would be useful tools in molecular biology and potentially in human medicine. Simple rules have been developed to rationally alter the sequence specificity of minor groove-binding polyamides containing N-methyl...

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

authors： Cho J,Parks ME,Dervan PB

更新日期：1995-10-24 00:00:00

abstract：:E2A helix-loop-helix proteins are involved in the control of various developmental pathways. We show here by in situ hybridization that E2A transcripts are present in most embryonic and adult tissues. However, no E2A expression is detectable in heart and nonproliferative regions of the brain and spinal cord. Highest l...

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

authors： Roberts VJ,Steenbergen R,Murre C

更新日期：1993-08-15 00:00:00

abstract：:The gene IL-3 encodes interleukin 3, a hematopoietic colony-stimulating factor (CSF) that is capable of supporting the proliferation of a broad range of hematopoietic cell types. By using somatic cell hybrids and in situ chromosomal hybridization, we localized this gene to human chromosome 5 at bands q23-31, a chromos...

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

authors： Le Beau MM,Epstein ND,O'Brien SJ,Nienhuis AW,Yang YC,Clark SC,Rowley JD

更新日期：1987-08-01 00:00:00

abstract：:G protein-coupled receptors mediate biological signals by stimulating nucleotide exchange in heterotrimeric G proteins (Galphabetagamma). Receptor dimers have been proposed as the functional unit responsible for catalytic interaction with Galphabetagamma. To investigate whether a G protein-coupled receptor monomer can...

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

authors： Ernst OP,Gramse V,Kolbe M,Hofmann KP,Heck M

更新日期：2007-06-26 00:00:00

abstract：:Prompted by the increasing interest in networks in many fields, we present an attempt at unifying points of view and analyses of these objects coming from the social sciences, statistics, probability and physics communities. We apply our approach to the Newman-Girvan modularity, widely used for "community" detection, ...

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

authors： Bickel PJ,Chen A

更新日期：2009-12-15 00:00:00

abstract：:Bone morphogenetic protein (BMP) signaling plays a major role in dorsoventral patterning in vertebrates and in Drosophila. Remarkably, in Tribolium, a beetle with an ancestral type of insect development, early BMP/dpp exhibits differential expression along the anteroposterior axis. However, the BMP/Dpp inhibitor Sog/c...

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

authors： van der Zee M,Stockhammer O,von Levetzow C,Nunes da Fonseca R,Roth S

更新日期：2006-10-31 00:00:00

abstract：:A hallmark of most neurodegenerative diseases, including those caused by polyglutamine expansion, is the formation of ubiquitin (Ub)-positive protein aggregates in affected neurons. This finding suggests that the Ub system may be involved in common mechanisms underlying these otherwise unrelated diseases. Here we repo...

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

authors： Donaldson KM,Li W,Ching KA,Batalov S,Tsai CC,Joazeiro CA

更新日期：2003-07-22 00:00:00

abstract：:Trisomy is a genetic abnormality of considerable medical importance. The most familiar example is trisomy 21, which causes Down Syndrome [Cummings, M. R. (1988) Human Heredity: Principles and Issues (West Publishing Company, New York)]. In a classic paper, Axelrod and Hamilton [Axelrod, R. & Hamilton, W. D. (1981) Sci...

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

authors： Day T,Taylor PD

更新日期：1998-03-03 00:00:00

abstract：:The X-ray crystal structure of the Head module, one-third of the Mediator of transcriptional regulation, has been determined as a complex with the C-terminal domain (CTD) of RNA polymerase II. The structure reveals multiple points of interaction with an extended conformation of the CTD; it suggests a basis for regulat...

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

authors： Robinson PJ,Bushnell DA,Trnka MJ,Burlingame AL,Kornberg RD

更新日期：2012-10-30 00:00:00

abstract：:DNA was extracted from the remains of 35 ground sloths from various parts of North and South America. Two specimens of Mylodon darwinii, a species that went extinct at the end of the last glaciation, yielded amplifiable DNA. However, of the total DNA extracted, only approximately 1/1000 originated from the sloth, wher...

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

authors： Höss M,Dilling A,Currant A,Pääbo S

更新日期：1996-01-09 00:00:00

abstract：:Nonenzymatic manganese was first shown to provide protection against superoxide toxicity in vivo in 1981, but the chemical mechanism responsible for this protection subsequently became controversial due to conflicting reports concerning the ability of Mn to catalyze superoxide disproportionation in vitro. In a recent ...

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

authors： Barnese K,Gralla EB,Valentine JS,Cabelli DE

更新日期：2012-05-01 00:00:00

abstract：:Methods for the construction of ordered nanoscale arrays have been implicated in fields ranging from separation technologies to microelectronics. Yet, despite the plethora of nanoscale structures assembled in nature that use a templating strategy, chemists have been unable to replicate this success. A technology is re...

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

authors： Willis B,Eubanks LM,Wood MR,Janda KD,Dickerson TJ,Lerner RA

更新日期：2008-02-05 00:00:00

abstract：:Stochasticity alters the nonlinear dynamics of inherently cycling populations. The power spectrum can describe and explain the impacts of stochasticity. We fitted models to short observed time series of flour beetle populations in the frequency domain, then used a well fitting stochastic mechanistic model to generate ...

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

authors： Reuman DC,Desharnais RA,Costantino RF,Ahmad OS,Cohen JE

更新日期：2006-12-05 00:00:00

abstract：:Treatment of cultured Hodgkin disease (HD) cells with neuraminidase results in decreased reactivity of monoclonal antibody VIM-D5 with its antigen, the X hapten, a fucosyl-N-acetyllactosamine. The other feature characteristic of HD cells is the expression of high levels of ectosialyltransferase activity. We present ev...

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

authors： Paietta E,Stockert RJ,Morell AG,Diehl V,Wiernik PH

更新日期：1986-05-01 00:00:00

abstract：:Mutant forms of the BRCA2 gene contribute significantly to hereditary breast cancer. Isolation of the normal and mutant forms of the BRCA2 gene with its natural promoter would greatly facilitate analysis of the gene and its contribution to breast cancer. We have accomplished the direct isolation of the 90-kb gene from...

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

authors： Larionov V,Kouprina N,Solomon G,Barrett JC,Resnick MA

更新日期：1997-07-08 00:00:00

abstract：:Mutations in sequences at the C terminus of the capsid precursor protein of human immunodeficiency virus type 1 that affect the viral p6 protein prevent release of budded virus particles from the cell surface. The experiments reported here define an important step in the life cycle of the virus, the release of the bud...

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

authors： Göttlinger HG,Dorfman T,Sodroski JG,Haseltine WA

更新日期：1991-04-15 00:00:00

abstract：:Speech recognition involves three processes: extraction of acoustic indices from the speech signal, estimation of the probability that the observed index string was caused by a hypothesized utterance segment, and determination of the recognized utterance via a search among hypothesized alternatives. This paper is not ...

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

authors： Jelinek F

更新日期：1995-10-24 00:00:00

abstract：:Climate change is expected to cause shifts in the composition of tropical montane forests towards increased relative abundances of species whose ranges were previously centered at lower, hotter elevations. To investigate this process of "thermophilization," we analyzed patterns of compositional change over the last de...

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

authors： Duque A,Stevenson PR,Feeley KJ

更新日期：2015-08-25 00:00:00

abstract：:Understanding mammalian spermatozoan development and the events surrounding fertilization has grown slowly, in part because of uncertainty about the number and identity of the cellular components involved. Determination of those transcripts expressed specifically by germ cells should provide an inclusive list of proba...

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

authors： Schultz N,Hamra FK,Garbers DL

更新日期：2003-10-14 00:00:00

abstract：:Most simian-human immunodeficiency viruses (SHIVs) bearing envelope (Env) glycoproteins from primary HIV-1 strains fail to infect rhesus macaques (RMs). We hypothesized that inefficient Env binding to rhesus CD4 (rhCD4) limits virus entry and replication and could be enhanced by substituting naturally occurring simian...

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

authors： Li H,Wang S,Kong R,Ding W,Lee FH,Parker Z,Kim E,Learn GH,Hahn P,Policicchio B,Brocca-Cofano E,Deleage C,Hao X,Chuang GY,Gorman J,Gardner M,Lewis MG,Hatziioannou T,Santra S,Apetrei C,Pandrea I,Alam SM,Liao HX,

更新日期：2016-06-14 00:00:00

abstract：:Understanding and manipulation of the forces assembling DNA/RNA helices have broad implications for biology, medicine, and physics. One subject of significance is the attractive force between dsDNA mediated by polycations of valence ≥ 3. Despite extensive studies, the physical origin of the "like-charge attraction" re...

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

authors： Qiu X,Parsegian VA,Rau DC

更新日期：2010-12-14 00:00:00

abstract：:Imbalances between proinflammatory and proresolving mediators can lead to chronic inflammatory diseases. The balance of arachidonic acid-derived mediators in leukocytes is thought to be achieved through intracellular localization of 5-lipoxygenase (5-LOX): nuclear 5-LOX favors the biosynthesis of proinflammatory leuko...

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

authors： Fredman G,Ozcan L,Spolitu S,Hellmann J,Spite M,Backs J,Tabas I

更新日期：2014-10-07 00:00:00

abstract：:Huntington disease (HD) is a neurodegenerative disorder caused by a CAG expansion within the huntingtin gene that encodes a polymorphic glutamine tract at the amino terminus of the huntingtin protein. HD is one of nine polyglutamine expansion diseases. The clinical threshold of polyglutamine expansion for HD is near 3...

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

authors： Caron NS,Desmond CR,Xia J,Truant R

更新日期：2013-09-03 00:00:00

abstract：:It has been known for more than a century that increases in neuronal activity in the brain are reliably accompanied by changes in local blood flow. More recently it has been appreciated that these blood flow increases are accompanied by increases in glycolysis that are much greater than the increases in oxidative phos...

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

authors： Vlassenko AG,Rundle MM,Raichle ME,Mintun MA

更新日期：2006-02-07 00:00:00

abstract：:We have reported previously that murine bone marrow-derived dendritic cells (DC) pulsed with whole tumor lysates can mediate potent antitumor immune responses both in vitro and in vivo. Because successful therapy was dependent on host immune T cells, we have now evaluated whether the systemic administration of the T c...

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

authors： Shimizu K,Fields RC,Giedlin M,Mulé JJ

更新日期：1999-03-02 00:00:00