Abstract：
:The discipline-wide effort to database the fossil record at the occurrence level has made it possible to estimate marine invertebrate extinction and origination rates with much greater accuracy. The new data show that two biotic mechanisms have hastened recoveries from mass extinctions and confined diversity to a relatively narrow range over the past 500 million years (Myr). First, a drop in diversity of any size correlates with low extinction rates immediately afterward, so much so that extinction would almost come to a halt if diversity dropped by 90%. Second, very high extinction rates are followed by equally high origination rates. The two relationships predict that the rebound from the current mass extinction will take at least 10 Myr, and perhaps 40 Myr if it rivals the Permo-Triassic catastrophe. Regardless, any large event will result in a dramatic ecological and taxonomic restructuring of the biosphere. The data also confirm that extinction and origination rates both declined through the Phanerozoic and that several extinctions in addition to the Permo-Triassic event were particularly severe. However, the trend may be driven by taxonomic biases and the rates vary in accord with a simple log normal distribution, so there is no sharp distinction between background and mass extinctions. Furthermore, the lack of any significant autocorrelation in the data is inconsistent with macroevolutionary theories of periodicity or self-organized criticality.
journal_name
Proc Natl Acad Sci U S Aauthors
Alroy Jdoi
10.1073/pnas.0802597105subject
Has Abstractpub_date
2008-08-12 00:00:00pages
11536-42eissn
0027-8424issn
1091-6490pii
0802597105journal_volume
105 Suppl 1pub_type
杂志文章abstract：:Although Hsp90 displays general chaperone activity in vitro, few substrates of the chaperone have been identified in vivo, and the characteristics that render these substrates dependent on Hsp90 remain elusive. To investigate this issue, we exploited a paradoxical observation: several unrelated oncogenic viral tyrosin...
journal_title：Proceedings of the National Academy of Sciences of the United States of America
pub_type： 杂志文章
doi：10.1073/pnas.96.1.109
更新日期：1999-01-05 00:00:00
abstract：:Sour taste is detected by a subset of taste cells on the tongue and palate epithelium that respond to acids with trains of action potentials. Entry of protons through a Zn(2+)-sensitive proton conductance that is specific to sour taste cells has been shown to be the initial event in sour taste transduction. Whether th...
journal_title：Proceedings of the National Academy of Sciences of the United States of America
pub_type： 杂志文章
doi：10.1073/pnas.1514282112
更新日期：2016-01-12 00:00:00
abstract：:Model compositions of Earth, Venus, and Mercury are calculated from the premise that planets and chondrites underwent four identical fractionation processes in the solar nebula. Because elements of similar properties stay together in these processes, five constraints suffice to define the composition of a planet: mass...
journal_title：Proceedings of the National Academy of Sciences of the United States of America
pub_type： 杂志文章
doi：10.1073/pnas.77.12.6973
更新日期：1980-12-01 00:00:00
abstract：:Selection is usually considered to be the dominant force controlling viral variation; the large population sizes suggest that deterministic population genetic models are appropriate. To investigate their validity for HIV, samples of env gene sequences were tested for departure from neutrality because of mutation-selec...
journal_title：Proceedings of the National Academy of Sciences of the United States of America
pub_type： 杂志文章
doi：10.1073/pnas.94.5.1862
更新日期：1997-03-04 00:00:00
abstract：:DNA damage leads to a halt in proliferation owing to apoptosis or senescence, which prevents transmission of DNA alterations. This cellular response depends on the tumor suppressor p53 and functions as a powerful barrier to tumor development. Adult stem cells are resistant to DNA damage-induced apoptosis or senescence...
journal_title：Proceedings of the National Academy of Sciences of the United States of America
pub_type： 杂志文章
doi：10.1073/pnas.1213394110
更新日期：2013-03-05 00:00:00
abstract：:E2F is a heterodimeric transcription factor that regulates the expression of genes at the G1/S boundary and is composed of two related but distinct families of proteins, E2F and DP. E2F/DP heterodimers form complexes with the retinoblastoma (Rb) protein, the Rb-related proteins p107 and p130, and cyclins/cdks in a cel...
journal_title：Proceedings of the National Academy of Sciences of the United States of America
pub_type： 杂志文章
doi：10.1073/pnas.93.15.7594
更新日期：1996-07-23 00:00:00
abstract：:We have expressed a male-specific, pheromone-sensitive odorant receptor (OR), BmorOR1, from the silkworm moth Bombyx mori in an "empty neuron" housed in the ab3 sensilla of a Drosophila Deltahalo mutant. Single-sensillum recordings showed that the BmorOR1-expressing neurons in the transgenic flies responded to the B. ...
journal_title：Proceedings of the National Academy of Sciences of the United States of America
pub_type： 杂志文章
doi：10.1073/pnas.0607874103
更新日期：2006-10-31 00:00:00
abstract：:Mass cytometry enables an unprecedented number of parameters to be measured in individual cells at a high throughput, but the large dimensionality of the resulting data severely limits approaches relying on manual "gating." Clustering cells based on phenotypic similarity comes at a loss of single-cell resolution and o...
journal_title：Proceedings of the National Academy of Sciences of the United States of America
pub_type： 杂志文章
doi：10.1073/pnas.1321405111
更新日期：2014-01-07 00:00:00
abstract：:Ubiquitin E3 ligases are crucial for eliminating misfolded proteins before they form cytotoxic aggregates that threaten cell fitness and survival. However, it remains unclear how emerging misfolded proteins in the cytoplasm can be selectively recognized and eliminated by E3 ligases in plants. We found that Misfolded P...
journal_title：Proceedings of the National Academy of Sciences of the United States of America
pub_type： 杂志文章
doi：10.1073/pnas.1713574114
更新日期：2017-11-14 00:00:00
abstract：:Linear porphyrin arrays self-assembled by either hydrogen bonding or metal ion coordination self-organize into lipid bilayer membranes. The length of the transmembrane assemblies is determined both by the thermodynamics of the intermolecular interactions in the supermolecule and by the dimension and physical chemical ...
journal_title：Proceedings of the National Academy of Sciences of the United States of America
pub_type： 杂志文章
doi：10.1073/pnas.062635099
更新日期：2002-04-16 00:00:00
abstract：:Mutations affecting mismatch repair result in elevated frequencies of microsatellite length alteration in prokaryotes and eukaryotes. However, the finding that microsatellite instability is found often in cells with a functional mismatch repair system prompted a search for other factors of tract alteration. In the pre...
journal_title：Proceedings of the National Academy of Sciences of the United States of America
pub_type： 杂志文章
doi：10.1073/pnas.95.17.10003
更新日期：1998-08-18 00:00:00
abstract：:Acetyl-CoA synthase from Clostridium thermoaceticum (ACS(Ct)) is an alpha(2)beta(2) tetramer containing two novel Ni-X-Fe(4)S(4) active sites (the A and C clusters) and a standard Fe(4)S(4) cluster (the B cluster). The acsA and acsB genes encoding the enzyme were cloned into Escherichia coli strain JM109 and overexpre...
journal_title：Proceedings of the National Academy of Sciences of the United States of America
pub_type： 杂志文章
doi：10.1073/pnas.220404397
更新日期：2000-11-07 00:00:00
abstract：:Transgenic mice expressing the sequences coding for the envelope proteins of the hepatitis B virus (HBV) in the liver have been used as a model of the HBV chronic carrier state. We evaluated the possibility of inducing a specific immune response to the viral envelope antigens and thus potentially controlling chronic H...
journal_title：Proceedings of the National Academy of Sciences of the United States of America
pub_type： 杂志文章
doi：10.1073/pnas.93.22.12496
更新日期：1996-10-29 00:00:00
abstract：:Molecular diversity of ion channel structure and function underlies variability in electrical signaling in nerve, muscle, and nonexcitable cells. Regulation by variable auxiliary subunits is a major mechanism to generate tissue- or cell-specific diversity of ion channel function. Mammalian large-conductance, voltage- ...
journal_title：Proceedings of the National Academy of Sciences of the United States of America
pub_type： 杂志文章
doi：10.1073/pnas.1205435109
更新日期：2012-05-15 00:00:00
abstract：:High sensitivity differential scanning calorimetry is applied to the study of the thermotropic behavior of mixtures of synthetic phospholipids in multilamellar aqueous suspensions. The systems dimyristoylphosphatidylcholine dipalmitoylphosphatidylcholine, and dimyristoylphosphatidylethanolamine-distearoylphosphatidyl...
journal_title：Proceedings of the National Academy of Sciences of the United States of America
pub_type： 杂志文章
doi：10.1073/pnas.73.11.3862
更新日期：1976-11-01 00:00:00
abstract：:Retinoblastoma is a childhood tumor that can arise because of mutant alleles acquired as somatic or germinal mutations. The mutant allele can be carried in the germ line. The mutations creating these alleles act by inactivating copies of a recessive oncogene located within band q14 of chromosome 13 and termed the RB1 ...
journal_title：Proceedings of the National Academy of Sciences of the United States of America
pub_type： 杂志文章
doi：10.1073/pnas.84.24.9059
更新日期：1987-12-01 00:00:00
abstract：:The Drosophila melanogaster urate oxidase (UO)-encoding gene is expressed in the third-instar larva and adult. In contrast, the Drosophila pseudoobscura UO gene is only expressed in the adult, whereas the Drosophila virilis UO gene is expressed only in the third-instar larva. UO activity in these three Drosophila spec...
journal_title：Proceedings of the National Academy of Sciences of the United States of America
pub_type： 杂志文章
doi：10.1073/pnas.88.13.5489
更新日期：1991-07-01 00:00:00
abstract：:Expression of the human beta amyloid peptide (A beta) in transgenic Caenorhabditis elegans animals can lead to the formation of intracellular immunoreactive deposits as well as the formation of intracellular amyloid. We have used this model to identify proteins that interact with intracellular A beta in vivo. Mass spe...
journal_title：Proceedings of the National Academy of Sciences of the United States of America
pub_type： 杂志文章
doi：10.1073/pnas.152313999
更新日期：2002-07-09 00:00:00
abstract：:In biological processes, such as fission, fusion and trafficking, it has been shown that lipids of different shapes are sorted into regions with different membrane curvatures. This lipid sorting has been hypothesized to be due to the coupling between the membrane curvature and the lipid's spontaneous curvature, which ...
journal_title：Proceedings of the National Academy of Sciences of the United States of America
pub_type： 杂志文章
doi：10.1073/pnas.0907354106
更新日期：2009-12-29 00:00:00
abstract：:In recent years, the field of psychology has begun to conduct replication tests on a large scale. Here, we show that "replicator degrees of freedom" make it far too easy to obtain and publish false-negative replication results, even while appearing to adhere to strict methodological standards. Specifically, using data...
journal_title：Proceedings of the National Academy of Sciences of the United States of America
pub_type： 杂志文章
doi：10.1073/pnas.1910951116
更新日期：2019-12-17 00:00:00
abstract：:The torI gene has been identified by using a genetic multicopy approach as a negative regulator of the torCAD operon that encodes the trimethylamine N-oxide reductase respiratory system in Escherichia coli. The negative effect was due to a previously unidentified small ORF (66 aa) of phage origin that we called torI f...
journal_title：Proceedings of the National Academy of Sciences of the United States of America
pub_type： 杂志文章
doi：10.1073/pnas.0401927101
更新日期：2004-06-22 00:00:00
abstract：:Phototropin, a major blue-light receptor for phototropism in seed plants, exhibits blue-light-dependent autophosphorylation and contains two light, oxygen, or voltage (LOV) domains and a serine/threonine kinase domain. The LOV domains share homology with the PER-ARNT-SIM (PAS) superfamily, a diverse group of sensor pr...
journal_title：Proceedings of the National Academy of Sciences of the United States of America
pub_type： 杂志文章
doi：10.1073/pnas.051520298
更新日期：2001-03-13 00:00:00
abstract：:Adult stem cells represent unique populations of undifferentiated cells with self-renewal capacity. In many tissues, stem cells divide less often than their progeny. It has been widely speculated, but largely untested, that their undifferentiated and quiescent state may make stem cells more efficient as donors for clo...
journal_title：Proceedings of the National Academy of Sciences of the United States of America
pub_type： 杂志文章
doi：10.1073/pnas.0611358104
更新日期：2007-02-20 00:00:00
abstract：:Muscarinic acetylcholine receptors (mAChR) in the embryonic chicken heart undergo agonist-induced internalization and a subsequent decrease in receptor number (downregulation). Cloning studies have identified two subtypes of mAChR expressed in the embryonic chicken heart, the cm2 and cm4 receptors. We report here that...
journal_title：Proceedings of the National Academy of Sciences of the United States of America
pub_type： 杂志文章
doi：10.1073/pnas.89.11.5035
更新日期：1992-06-01 00:00:00
abstract：:A striking and widespread observation is that higher-order folding for many RNAs is very slow, often requiring minutes. In some cases, slow folding reflects the need to disrupt stable, but incorrect, interactions. However, a molecular explanation for slow folding in most RNAs is unknown. The specificity domain of the ...
journal_title：Proceedings of the National Academy of Sciences of the United States of America
pub_type： 杂志文章
doi：10.1073/pnas.0901319106
更新日期：2009-09-15 00:00:00
abstract：:The crystal structure of DsRed, a red fluorescent protein from a corallimorpharian, has been determined at 2.0-A resolution by multiple-wavelength anomalous dispersion and crystallographic refinement. Crystals of the selenomethionine-substituted protein have space group P2(1) and contain a tetramer with 222 noncrystal...
journal_title：Proceedings of the National Academy of Sciences of the United States of America
pub_type： 杂志文章
doi：10.1073/pnas.98.2.462
更新日期：2001-01-16 00:00:00
abstract：:The chloroplast stromal proteins from spinach condense the two heterocyclic moieties of vitamin B1--4-methyl-5-(beta-hydroxyethyl)thiazole and 2-methyl-4-amino-5-hydroxymethylpyrimidine--in the presence of MgATP. We have taken advantage of this observation to study thiazole synthesis. We present data indicating that p...
journal_title：Proceedings of the National Academy of Sciences of the United States of America
pub_type： 杂志文章
doi：10.1073/pnas.88.6.2042
更新日期：1991-03-15 00:00:00
abstract：:An understanding of the division of labor in different societies, and especially how it evolved in the human species, is fundamental to most analyses of social, political, and economic systems. The ability to reconstruct how labor was organized, however, especially in ancient societies that left behind few material re...
journal_title：Proceedings of the National Academy of Sciences of the United States of America
pub_type： 历史文章,杂志文章
doi：10.1073/pnas.1901367116
更新日期：2019-06-18 00:00:00
abstract：:Tactoids are nuclei of an orientationally ordered nematic phase that emerge upon cooling the isotropic phase. In addition to providing a natural setting for exploring chromonics under confinement, we show that tactoids can also serve as optical probes to delineate the role of temperature and concentration in the aggre...
journal_title：Proceedings of the National Academy of Sciences of the United States of America
pub_type： 杂志文章
doi：10.1073/pnas.1614620114
更新日期：2017-04-11 00:00:00
abstract：:Disruption of latent Epstein-Barr virus (EBV) infection is induced by the key immediate-early protein BZLF1 (or Z, a member of the basic leucine-zipper family), which transactivates the viral early promoters. Viral reactivation is marked by renewed synthesis of early gene products such as EBV early antigen-diffuse (EA...
journal_title：Proceedings of the National Academy of Sciences of the United States of America
pub_type： 杂志文章
doi：10.1073/pnas.90.9.3894
更新日期：1993-05-01 00:00:00
