Abstract:
:It is widely accepted that modern humans originated in sub-Saharan Africa approximately 150-200 thousand years ago (ka), but their route of dispersal across the currently hyperarid Sahara remains controversial. Given that the first modern humans north of the Sahara are found in the Levant approximately 120-90 ka, northward dispersal likely occurred during a humid episode in the Sahara within Marine Isotope Stage (MIS) 5e (130-117 ka). The obvious dispersal route, the Nile, may be ruled out by notable differences between archaeological finds in the Nile Valley and the Levant at the critical time. Further west, space-born radar images reveal networks of-now buried-fossil river channels that extend across the desert to the Mediterranean coast, which represent alternative dispersal corridors. These corridors would explain scattered findings at desert oases of Middle Stone Age Aterian lithic industries with bifacial and tanged points that can be linked with industries further to the east and as far north as the Mediterranean coast. Here we present geochemical data that demonstrate that water in these fossil systems derived from the south during wet episodes in general, and penetrated all of the way to the Mediterranean during MIS 5e in particular. This proves the existence of an uninterrupted freshwater corridor across a currently hyperarid region of the Sahara at a key time for early modern human migrations to the north and out of Africa.
journal_name
Proc Natl Acad Sci U S Aauthors
Osborne AH,Vance D,Rohling EJ,Barton N,Rogerson M,Fello Ndoi
10.1073/pnas.0804472105subject
Has Abstractpub_date
2008-10-28 00:00:00pages
16444-7issue
43eissn
0027-8424issn
1091-6490pii
0804472105journal_volume
105pub_type
历史文章,杂志文章abstract::The calcium, calmodulin-dependent phosphatase calcineurin, regulates growth and gene expression of striated muscles. The activity of calcineurin is modulated by a family of cofactors, referred to as modulatory calcineurin-interacting proteins (MCIPs). In the heart, the MCIP1 gene is activated by calcineurin and has 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.0308723101
更新日期:2004-03-02 00:00:00
abstract::Engagement of high-affinity IgE receptors leads to activation of tyrosine and serine/threonine kinases and the immediate phosphorylation of receptor beta (serine and tyrosine) and gamma (threonine and tyrosine) chains. Receptor disengagement leads to dephosphorylation of beta and gamma chains via the action of undefin...
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.89.22.10733
更新日期:1992-11-15 00:00:00
abstract::Two major themes in the physics of condensed matter are quantum critical phenomena and unconventional superconductivity. These usually occur in the context of competing interactions in systems of strongly correlated electrons. All this interesting physics comes together in the behavior of the recently discovered iron ...
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.0900886106
更新日期:2009-03-17 00:00:00
abstract::The positions of transition states along reaction coordinates (r++) for simple chemical reactions are often estimated from Leffler alpha values, the slope of plots of DeltaG++ (activation energy) versus DeltaG(0) (equilibrium free energy) for a series of structural variants. Protein folding is more complex than simple...
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.0406091101
更新日期:2004-10-05 00:00:00
abstract::The biosynthetic origin of the 10,000 molecular weight neurophysins, carriers of the peptide hormones oxytocin and vasopressin, has been studied by cell-free synthesis, Poly(A)-RNA was isolated from bovine hypothalamus and translated in a wheat germ system containing (35)S- or (3)H-labeled amino acids. A number of uni...
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.76.8.3800
更新日期:1979-08-01 00:00:00
abstract::With the completion of genome sequences of major model organisms, increasingly sophisticated genetic tools are necessary for investigating the complex and coordinated functions of genes. Here we describe a genetic manipulation system termed "genomic engineering" in Drosophila. Genomic engineering is a 2-step process 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.0900641106
更新日期:2009-05-19 00:00:00
abstract::Little is known about how genetic variation and epigenetic marks interact to shape differences in behavior. The foraging (for) gene regulates behavioral differences between the rover and sitter Drosophila melanogaster strains, but the molecular mechanisms through which it does so have remained elusive. We show that 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.1710770114
更新日期:2017-11-21 00:00:00
abstract::When deprived of D-glucose for 24 hr, chicken embryo fibroblasts exhibit a marked increase in hexose transport activity compared with that of control cells. Scatchard analysis of [3H]cytochalasin B binding to starved cell plasma membranes (46 pmol/mg) indicated a six-fold increase compared with fed cell plasma membran...
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.79.7.2286
更新日期:1982-04-01 00:00:00
abstract::Hydrogen bond networks are key elements of protein structure and function but have been challenging to study within the complex protein environment. We have carried out in-depth interrogations of the proton transfer equilibrium within a hydrogen bond network formed to bound phenols in the active site of ketosteroid is...
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.1302191110
更新日期:2013-07-09 00:00:00
abstract::Injection of antisense oligonucleotides was used to investigate the function of c-mos in murine oocytes. Oocytes injected with antisense c-mos oligonucleotides completed the first meiotic division but failed to initiate meiosis II. Instead, loss of c-mos function led to chromosome decondensation, reformation of a nucl...
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.86.18.7038
更新日期:1989-09-01 00:00:00
abstract::In normal adult rats anesthetized with urethane, intravenous injections of beta-endorphin (30--150 micrograms kg-1) induced a transient fall of blood pressure followed by a small hypertension and a prolonged hypotension. Prior administration of naloxone completely blocked these effects, whereas naloxone, given 1 hr af...
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.75.12.6240
更新日期:1978-12-01 00:00:00
abstract::The presynaptic plasma membrane protein SNAP-25 (synaptosome-associated protein of 25 kDa) has been implicated as one of several neural-specific components that direct constitutive fusion mechanisms to the regulated vesicle trafficking and exocytosis of neurotransmitter release. There exist two alternatively spliced i...
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.92.5.1510
更新日期:1995-02-28 00:00:00
abstract::By exploiting the ability of Pseudomonas aeruginosa to infect a variety of vertebrate and nonvertebrate hosts, we have developed model systems that use plants and nematodes as adjuncts to mammalian models to help elucidate the molecular basis of P. aeruginosa pathogenesis. Our studies reveal a remarkable degree of con...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章,评审
doi:10.1073/pnas.97.16.8815
更新日期:2000-08-01 00:00:00
abstract::The hallmark of the menstrual cycle is extensive steroid-dependent tissue turnover. Estrogen mediates endometrial cell growth and structural remodeling, whereas progesterone suppresses estrogen-dependent proliferation and promotes cellular differentiation. In nonfertile cycles, tissue degradation and menstruation occu...
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.91.21.10129
更新日期:1994-10-11 00:00:00
abstract::Transmural stimulation of the isolated adrenal gland of the rat and guinea pig results in secretion of catecholamine. The secretion is due to activation of cholinergic receptors of the adrenal medulla by acetylcholine released from splanchnic nerve terminals after transmural stimulation. Our aim was to see whether 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.79.9.3071
更新日期:1982-05-01 00:00:00
abstract::Conflicts of interest between the community and its members are at the core of human social dilemmas. If observed selfishness has future costs, individuals may hide selfish acts but display altruistic ones, and peers aim at identifying the most selfish persons to avoid them as future social partners. An interaction in...
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.1108996108
更新日期:2011-11-08 00:00:00
abstract::RNA interference (RNAi) is triggered in eukaryotic organisms by double-stranded RNA (dsRNA), and it destroys any mRNA that has sequence identity with the dsRNA trigger. The RNAi pathway in Anopheles gambiae can be silenced by transfecting cells with dsRNA derived from exon sequence of the A. gambiae Argonaute2 (AgAgo2...
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.0406983101
更新日期:2004-12-07 00:00:00
abstract::5 alpha-Cholest-8(14)-en-3 beta-ol-15-one has been found to have significant hypocholesterolemic activity upon oral administration at a daily dosage of 75 mg/kg of body weight to Rhesus monkeys fed a diet of moderate cholesterol (Chol) content [0.19 mg/kcal (1 cal = 4.184 J) of diet]. The reductions in total serum Cho...
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.81.21.6861
更新日期:1984-11-01 00:00:00
abstract::The lineage-determining transcription factor CCAAT enhancer binding protein alpha (C/EBPalpha) is required for myeloid differentiation. Decreased function or expression of C/EBPalpha is often found in human acute myeloid leukemia. However, the precise impact of C/EBPalpha deficiency on the maturation arrest in leukemo...
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.0508143103
更新日期:2006-04-18 00:00:00
abstract::In Huntington's disease (HD), mutation of huntingtin causes selective neurodegeneration of dopaminoceptive striatal medium spiny neurons. Transgenic HD model mice that express a portion of the disease-causing form of human huntingtin develop a behavioral phenotype that suggests dysfunction of dopaminergic neurotransmi...
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.120166397
更新日期:2000-06-06 00:00:00
abstract::Peroxisome proliferators cause rapid and coordinated transcriptional activation of genes encoding peroxisomal beta-oxidation system enzymes by activating peroxisome proliferator-activated receptor (PPAR) isoform(s). Since the thyroid hormone (T3; 3,3',5-triiodothyronine) receptor (TR), another member of the nuclear ho...
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.92.25.11593
更新日期:1995-12-05 00:00:00
abstract::Tumor-specific molecules are needed across diverse areas of oncology for use in early detection, diagnosis, prognosis and therapy. Large and growing public databases of transcriptome sequencing data (RNA-seq) derived from tumors and normal tissues hold the potential of yielding tumor-specific molecules, but because 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.1508057112
更新日期:2015-06-09 00:00:00
abstract::gC1qR is one of the C1q receptors implicated in the regulation of innate and adaptive immunity. We found that gC1qR inhibits RIG-I and MDA5-dependent antiviral signaling. Double stranded RNA and virus trigger the translocation of gC1qR to the mitochondrial outer membrane leading to the interaction of gC1qR with the RI...
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.0811029106
更新日期:2009-02-03 00:00:00
abstract::The Escherichia coli strain, ts-rnp5, originally described in 1975 by G. D. Burdick and H. Berger, is shown to possess an RNA polymerase (RNA nucleotidyltransferase) sigma subunit with an activity 4--6 times less thermostable at 45 degrees than sigma from wild-type strains. This defect remains associated with the sigm...
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.75.1.427
更新日期:1978-01-01 00:00:00
abstract::Photonic materials with positionally ordered structure can interact strongly with light to produce brilliant structural colors. Here, we found that the nonperiodic nematic liquid crystals of nanoplates can also display structural color with only significant orientational order. Owing to the loose stacking of the nemat...
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.1906511116
更新日期:2019-09-10 00:00:00
abstract::Egg laying hormone, a peptide neurohormone with an approximate molecular weight of 6000, was isolated from the region of the abdominal ganglion of Aplysia that contains the neuroendocrine bag cells and purified by gel filtration chromatography, isoelectric focusing, and dialysis. A 1-min local application of egg layin...
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.75.11.5732
更新日期:1978-11-01 00:00:00
abstract::Kinetic partitioning is predicted to be a general mechanism for proteins to fold into their well defined native three-dimensional structure from unfolded states following multiple folding pathways. However, experimental evidence supporting this mechanism is still limited. By using single-molecule atomic force microsco...
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.0706775105
更新日期:2008-02-12 00:00:00
abstract::Inhibin, a gonadal hormone capable of preferential suppression of pituitary follicle-stimulating hormone (FSH) secretion, has recently been purified. The major form of this protein is an alpha beta heterodimer encoded by two separate genes. In contrast to the FSH-suppressing action of the alpha beta heterodimer, 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.84.14.5082
更新日期:1987-07-01 00:00:00
abstract::Reaction networks displaying bistability provide a chemical mechanism for long-term memory storage in cells, as exemplified by many epigenetic switches. These biological systems are not only bistable but switchable, in the sense that they can be flipped from one state to the other by application of specific molecular ...
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.1212069109
更新日期:2012-11-20 00:00:00
abstract::Kdo (3-deoxy-d-manno-oct-2-ulosonic acid) is an eight-carbon sugar mostly confined to Gram-negative bacteria. It is often involved in attaching surface polysaccharides to their lipid anchors. α-Kdo provides a bridge between lipid A and the core oligosaccharide in all bacterial LPSs, whereas an oligosaccharide of β-Kdo...
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.1603146113
更新日期:2016-05-31 00:00:00