Abstract:
:The rate of change of climate codetermines the global warming impacts on natural and socioeconomic systems and their capabilities to adapt. Establishing past rates of climate change from temperature proxy data remains difficult given their limited spatiotemporal resolution. In contrast, past greenhouse gas radiative forcing, causing climate to change, is well known from ice cores. We compare rates of change of anthropogenic forcing with rates of natural greenhouse gas forcing since the Last Glacial Maximum and of solar and volcanic forcing of the last millennium. The smoothing of atmospheric variations by the enclosure process of air into ice is computed with a firn diffusion and enclosure model. The 20th century increase in CO(2) and its radiative forcing occurred more than an order of magnitude faster than any sustained change during the past 22,000 years. The average rate of increase in the radiative forcing not just from CO(2) but from the combination of CO(2), CH(4), and N(2)O is larger during the Industrial Era than during any comparable period of at least the past 16,000 years. In addition, the decadal-to-century scale rate of change in anthropogenic forcing is unusually high in the context of the natural forcing variations (solar and volcanoes) of the past millennium. Our analysis implies that global climate change, which is anthropogenic in origin, is progressing at a speed that is unprecedented at least during the last 22,000 years.
journal_name
Proc Natl Acad Sci U S Aauthors
Joos F,Spahni Rdoi
10.1073/pnas.0707386105subject
Has Abstractpub_date
2008-02-05 00:00:00pages
1425-30issue
5eissn
0027-8424issn
1091-6490pii
0707386105journal_volume
105pub_type
杂志文章abstract::The techniques of electrophoresis were used in a search for evidence of mutation affecting protein structure, the indicators being hemoglobin and a set of serum proteins and erythrocyte enzymes. Among 94,796 locus tests on Amerindians from Central and South America, there was no evidence for mutation. Among 105,649 lo...
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.77.10.6037
更新日期:1980-10-01 00:00:00
abstract::Gap junctions are specialized membrane regions that seem to mediate intercellular communication. They appear to contain closely packed arrays of equally sized particles all of which, upon freeze-cleaving, remain attached to one membrane leaflet and not to the other. One gap junction cleavage face, therefore, always ex...
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.69.5.1318
更新日期:1972-05-01 00:00:00
abstract::Most new genes are thought to evolve from preexisting genes but duplications of entire genes or shuffling of preexisting exons provides only a limited repertoire of new sequences that can be presented to a cell. Only pieces that previously existed can be used in the construction and any further divergence depends on t...
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.91.16.7506
更新日期:1994-08-02 00:00:00
abstract::The het-s locus of Podospora anserina is a heterokaryon incompatibility locus. The coexpression of the antagonistic het-s and het-S alleles triggers a lethal reaction that prevents the formation of viable heterokaryons. Strains that contain the het-s allele can display two different phenotypes, [Het-s] or [Het-s*], ac...
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.94.18.9773
更新日期:1997-09-02 00:00:00
abstract::Brief learning experience (classical conditioning) induces frequency-specific receptive-field (RF) plasticity in the auditory cortex, characterized as increased response to the frequency of the conditioned stimulus and decreased responses to most other frequencies, including the pretraining best frequency. This experi...
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.90.6.2394
更新日期:1993-03-15 00:00:00
abstract::Developmental hemoglobin switching involves sequential globin gene activations and repressions that are incompletely understood. Earlier observations, described herein, led us to hypothesize that nuclear ferritin is a repressor of the adult beta-globin gene in embryonic erythroid cells. Our data show that a ferritin-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.151147098
更新日期:2001-07-31 00:00:00
abstract::Three distinct forms of human alkaline phosphatase, presumably isozymes, are known, each apparently associated with a specific tissue. These are placental, intestinal, and liver (kidney and bone). We have used a specific immunoassay and HPLC to show that placental alkaline phosphatase is also present in extracts of li...
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.82.18.6080
更新日期:1985-09-01 00:00:00
abstract::Multiple cues, across multiple sensory modalities, are involved in mate choice in a wide range of animal taxa. This multiplicity leads to the prediction that, in adaptive radiations, sexual isolation results from divergence in multiple dimensions. However, difficulties in directly measuring preferences and detecting m...
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.1003537107
更新日期:2010-09-21 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
pub_type: 杂志文章
doi:10.1073/pnas.0913112107
更新日期:2010-04-20 00:00:00
abstract::Metabolism of [3-13C]alanine in the presence and absence of beta-hydroxybutyrate or ethanol has been followed at 25 degrees C by 13C NMR at 90.5 MHz in primary hepatocytes from untreated rats and rats treated with triiodothyronine and not allowed to eat for 24 hr. The phosphoenolpyruvate/pyruvate futile cycle was foll...
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.78.1.60
更新日期:1981-01-01 00:00:00
abstract::A long-term electrophoretic survey of genetic variants of serum albumin has identified an alloalbumin in 589 unrelated individuals in Italy. The alloalbumins were classified electrophoretically into 17 types. The number of unrelated carriers for each type varied from 1 for several variants reported here to 103 for alb...
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.87.22.8721
更新日期:1990-11-01 00:00:00
abstract::In adult skeletal muscles, 2 junctophilin isoforms (JPH1 and JPH2) tether the sarcoplasmic reticulum (SR) to transverse tubule (T-tubule) membranes, generating stable membrane contact sites known as triads. JPHs are anchored to the membrane of the SR by a C-terminal transmembrane domain (TMD) and bind the T-tubule mem...
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.1820980116
更新日期:2019-07-30 00:00:00
abstract::Certain mutations at the glaB locus result in the failure to fully derepress glutamine synthetase [L-glutamate:ammonia ligase (ADP-forming), EC 6.3.1.2] and to convert it to the active nonadenylylated form in response to nitrogen limitation. In these mutants the PII regulatory protein is altered such that it cannot be...
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.77.5.2636
更新日期:1980-05-01 00:00:00
abstract::The T-cell antigen receptor alpha-chain genes of an alloreactive, H-2Db-specific cytotoxic T-cell clone (3F9) are described. This study and our work on the 3F9 beta-chain genes reveal that the variable region gene segments for the alpha and beta chains expressed in 3F9 are identical to the ones used by a chicken eryth...
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.84.1.219
更新日期:1987-01-01 00:00:00
abstract::New approaches to the study of early hominin diets have refreshed interest in how and when our diets diverged from those of other African apes. A trend toward significant consumption of C4 foods in hominins after this divergence has emerged as a landmark event in human evolution, with direct evidence provided by stabl...
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.2006221117
更新日期:2020-09-08 00:00:00
abstract::Stimulation of the region antero-ventral to the third cerebral ventricle (AV3V) by a cholinergic drug, carbachol, and lesions of the AV3V have been demonstrated in previous studies to either augment or decrease sodium excretion, respectively. Atrial natriuretic peptide (ANP) dramatically increases renal sodium excreti...
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.86.23.9621
更新日期:1989-12-01 00:00:00
abstract::We have studied the effects of recombinant (r) interleukin 7 (IL-7) on growth and differentiation of marrow pro-B-lymphocyte clones (CB/Bm7, LyD9, LyB9), marrow pro-T-lymphocyte clones (C4-77/3, C4-86/18, C4-95/16), and fetal thymocyte clones (FTH5, FTA2, FTD5) in the presence or absence of the bone marrow stroma clon...
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.86.5.1634
更新日期:1989-03-01 00:00:00
abstract::Marine Archaea are important players among microbial plankton and significantly contribute to biogeochemical cycles, but details regarding their community structure and long-term seasonal activity and dynamics remain largely unexplored. In this study, we monitored the interannual archaeal community composition of abun...
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.1216863110
更新日期:2013-04-09 00:00:00
abstract::The 1.1 Å, ultrahigh resolution neutron structure of hydrogen/deuterium (H/D) exchanged crambin is reported. Two hundred ninety-nine out of 315, or 94.9%, of the hydrogen atom positions in the protein have been experimentally derived and resolved through nuclear density maps. A number of unconventional interactions ar...
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.1208341109
更新日期:2012-09-18 00:00:00
abstract::The biodistribution profiles in mice of two pyrrole-imidazole polyamides were determined by PET. Pyrrole-imidazole polyamides are a class of small molecules that can be programmed to bind a broad repertoire of DNA sequences, disrupt transcription factor-DNA interfaces, and modulate gene expression pathways in cell cul...
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.0806308105
更新日期:2008-09-02 00:00:00
abstract::The role of the products of the K and D loci of the H-2 complex as target antigens for cytotoxic T cells generated to modified syngeneic cells has been investigated. Spleen cells, when cocultured with trinitrophenyl-derivatized syngeneic cells, generate cytolytic T cells that lyse most effectively tumor or spleen targ...
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.73.2.625
更新日期:1976-02-01 00:00:00
abstract::The mechanisms for plant growth restriction during stress conditions remains unclear. Here, we demonstrate that a phytochrome-interacting factor-like protein, OsPIL1/OsPIL13, acts as a key regulator of reduced internode elongation in rice under drought conditions. The level of OsPIL1 mRNA in rice seedlings grown under...
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.1207324109
更新日期:2012-09-25 00:00:00
abstract::African sleeping sickness is a fatal disease that is caused by the protozoan parasite Trypanosoma brucei. Polyamine biosynthesis is an essential pathway in the parasite and is a validated drug target for treatment of the disease. S-adenosylmethionine decarboxylase (AdoMetDC) catalyzes a key step in polyamine biosynthe...
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.0701111104
更新日期:2007-05-15 00:00:00
abstract::Highly multiplexed assays using antibody coated, fluorescent (xMap) beads are widely used to measure quantities of soluble analytes, such as cytokines and antibodies in clinical and other studies. Current analyses of these assays use methods based on standard curves that have limitations in detecting low or high abund...
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.1112599109
更新日期:2012-02-21 00:00:00
abstract::Forkhead box g1 (Foxg1) is a nuclear-cytosolic transcription factor essential for the forebrain development and involved in neurodevelopmental and cancer pathologies. Despite the importance of this protein, little is known about the modalities by which it exerts such a large number of cellular functions. Here we show ...
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.1515190112
更新日期:2015-11-10 00:00:00
abstract::Mechanotransduction in the mammalian auditory system depends on mechanosensitive channels in the hair bundles that project from the apical surface of the sensory hair cells. Individual stereocilia within each bundle contain a core of tightly packed actin filaments, whose length is dynamically regulated during developm...
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.1304644110
更新日期:2013-08-20 00:00:00
abstract::Although the role of liganded nuclear receptors in mediating coactivator/corepressor exchange is well-established, little is known about the potential regulation of chromosomal organization in the 3-dimensional space of the nucleus in achieving integrated transcriptional responses to diverse signaling events. Here, we...
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.0810634105
更新日期:2008-12-09 00:00:00
abstract::Two striking differences between humans and our closest living relatives, chimpanzees and gorillas, are the size of our brains (larger by a factor of three or four) and our life span (longer by a factor of about two). Our thesis is that these two distinctive features of humans are products of coevolutionary selection....
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.152502899
更新日期:2002-07-23 00:00:00
abstract::The binding of chylomicron remnants rat liver plasma membranes was studied. Liver membranes bound up to 8 times more remnants than they bound chylomicrons. The remnant particle appeared to bind to the membrane as a unit. Remnant binding was greatest to liver plasma membrane; only one third as much binding was observed...
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.76.1.338
更新日期:1979-01-01 00:00:00
abstract::Low-temperature flash photolysis with IR and visible spectroscopy was used to probe the influence of the distal histidine His-64(E7) of sperm-whale myoglobin (Mb) on the orientation of bound carbon monoxide (CO) and on the kinetics of CO rebinding. The synthesis and high-level expression of a sperm-whale myoglobin gen...
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.85.22.8497
更新日期:1988-11-01 00:00:00