1: Science. 2006 Jun 16;312(5780):1644-6.
Comment in:
Science. 2006 Jun 16;312(5780):1587.
Phosphatized polar lobe-forming embryos from the Precambrian of southwest China.
Chen JY, Bottjer DJ, Davidson EH, Dornbos SQ, Gao X, Yang YH, Li CW, Li G, Wang
XQ, Xian DC, Wu HJ, Hwu YK, Tafforeau P.
Nanjing Institute of Geology and Paleontology, Institute of Evo/Developmental
Biology, and State Key Laboratory of Pharmaceutical Biotechnology, Nanjing
University, Nanjing 210093, China.
chenjy@nju.edu.cnIn developing embryos of some extant spiralian animals, polar lobe formation is
one of the symmetry-breaking mechanisms for segregation of maternal cytoplasmic
substances to certain blastomeres and not others. Polar lobe formation leads to
unique early cleavage morphologies that include trilobed, J-shaped, and
five-lobed structures. Fossil embryos similar to modern lobeforming embryos are
recognized from the Precambrian Doushantuo Formation phosphates, Weng'an,
Guizhou Province, China. These embryos are abundant and form a developmental
sequence comparable to different developing stages observed in lobe-forming
embryos of extant spiralians. These data imply that lobe formation is an
evolutionarily ancient process of embryonic specification.
PMID: 16778054 [PubMed - indexed for MEDLINE]
2: Science. 2006 Jun 16;312(5780):1640-3.
A nearly modern amphibious bird from the Early Cretaceous of northwestern China.
You HL, Lamanna MC, Harris JD, Chiappe LM, O'connor J, Ji SA, Lu JC, Yuan CX, Li
DQ, Zhang X, Lacovara KJ, Dodson P, Ji Q.
Institute of Geology, Chinese Academy of Geological Sciences, 26 Baiwanzhuang
Road, Beijing 100037, People's Republic of China.
Three-dimensional specimens of the volant fossil bird Gansus yumenensis from the
Early Cretaceous Xiagou Formation of northwestern China demonstrate that this
taxon possesses advanced anatomical features previously known only in Late
Cretaceous and Cenozoic ornithuran birds. Phylogenetic analysis recovers Gansus
within the Ornithurae, making it the oldest known member of the clade. The
Xiagou Formation preserves the oldest known ornithuromorph-dominated avian
assemblage. The anatomy of Gansus, like that of other non-neornithean
(nonmodern) ornithuran birds, indicates specialization for an amphibious
life-style, supporting the hypothesis that modern birds originated in aquatic or
littoral niches.
PMID: 16778053 [PubMed - indexed for MEDLINE]
3: Science. 2006 Jun 16;312(5780):1621.
The age of the Taklimakan Desert.
Sun J, Liu T.
State Key Laboratory of Lithospheric Evolution, Institute of Geology and
Geophysics, Chinese Academy of Sciences, Post Office Box 9825, Beijing 100029,
China.
jmsun@mail.igcas.ac.cnThe Taklimakan Desert is located in the foreland basin of the Tibetan Plateau.
We report here the results of stratigraphic investigations of a 1626-meter-thick
sequence with interbedded wind-blown silt from the southern marginal Taklimakan
Desert. Because the studied section is located downwind of the desert, the
eolian silt accumulation is closely linked to desert formation. Our new evidence
indicates that shifting sand dunes prevailed in the Tarim Basin by at least 5.3
million years ago, as they do today. We attribute this event to late Cenozoic
climatic deterioration, as well as to changes in atmospheric circulation induced
by Tibetan Plateau uplift.
PMID: 16778048 [PubMed]
4: Science. 2006 Jun 9;312(5779):1533-7.
Long-term potentiation of neuron-glia synapses mediated by Ca2+-permeable AMPA
receptors.
Ge WP, Yang XJ, Zhang Z, Wang HK, Shen W, Deng QD, Duan S.
Institute of Neuroscience and Key Laboratory of Neurobiology, Shanghai
Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai
200031, China.
shumin@ion.ac.cnInteractions between neurons and glial cells in the brain may serve important
functions in the development, maintenance, and plasticity of neural circuits.
Fast neuron-glia synaptic transmission has been found between hippocampal
neurons and NG2 cells, a distinct population of macroglia-like cells widely
distributed in the brain. We report that these neuron-glia synapses undergo
activity-dependent modifications analogous to long-term potentiation (LTP) at
excitatory synapses, a hallmark of neuronal plasticity. However, unlike the
induction of LTP at many neuron-neuron synapses, both induction and expression
of LTP at neuron-NG2 synapses involve Ca2+-permeable AMPA receptors on NG2
cells.
PMID: 16763153 [PubMed - indexed for MEDLINE]
5: Science. 2006 Jun 9;312(5779):1475-6.
Public health. HIV testing in China.
Wu Z, Sun X, Sullivan SG, Detels R.
National Center for AIDS/STD Control and Prevention, Chinese Center for Disease
Control and Prevention, Beijing 100050, PR China.
PMID: 16763133 [PubMed - indexed for MEDLINE]
6: Science. 2006 May 5;312(5774):731-4.
Lower Cambrian vendobionts from China and early diploblast evolution.
Shu DG, Morris SC, Han J, Li Y, Zhang XL, Hua H, Zhang ZF, Liu JN, Guo JF, Yao
Y, Yasui K.
Early Life Institute and Key Laboratory of Continental Dynamics, Northwest
University, Xi'an 710069, China.
elidgshu@nwu.edu.cnEdiacaran assemblages immediately predate the Cambrian explosion of metazoans
and should have played a crucial role in this radiation. Their wider
relationships, however, have remained refractory and difficult to integrate with
early metazoan phylogeny. Here, we describe a frondlike fossil, Stromatoveris
(S. psygmoglena sp. nov.), from the Lower Cambrian Chengjiang Lagerstatte
(Yunnan, China) that is strikingly similar to Ediacaran vendobionts. The
exquisite preservation reveals closely spaced branches, probably ciliated, that
appear to represent precursors of the diagnostic comb rows of ctenophores.
Therefore, this finding has important implications for the early evolution of
this phylum and related diploblasts, some of which independently evolved a
frondose habit.
PMID: 16675697 [PubMed - indexed for MEDLINE]
7: Science. 2006 Mar 10;311(5766):1440-3.
Comment in:
Science. 2006 Mar 10;311(5766):1383-5.
Observation of Feshbach resonances in the F + H2 --> HF + H reaction.
Qiu M, Ren Z, Che L, Dai D, Harich SA, Wang X, Yang X, Xu C, Xie D, Gustafsson
M, Skodje RT, Sun Z, Zhang DH.
State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of
Chemical Physics, Chinese Academy of Sciences, Dalian, Liaoning 116023, P. R.
China.
Reaction resonances, or transiently stabilized transition-state structures, have
proven highly challenging to capture experimentally. Here, we used the highly
sensitive H atom Rydberg tagging time-of-flight method to conduct a crossed
molecular beam scattering study of the F + H2 --> HF + H reaction with full
quantum-state resolution. Pronounced forward-scattered HF products in the v' = 2
vibrational state were clearly observed at a collision energy of 0.52 kcal/mol;
this was attributed to both the ground and the first excited Feshbach resonances
trapped in the peculiar HF(v' = 3)-H' vibrationally adiabatic potential, with
substantial enhancement by constructive interference between the two resonances.
PMID: 16527975 [PubMed - indexed for MEDLINE]
8: Science. 2006 Feb 24;311(5764):1127-9.
X-ray flares from postmerger millisecond pulsars.
Dai ZG, Wang XY, Wu XF, Zhang B.
Department of Astronomy, Nanjing University, Nanjing 210093, China.
dzg@nju.edu.cnRecent observations support the suggestion that short-duration gamma-ray bursts
are produced by compact star mergers. The x-ray flares discovered in two short
gamma-ray bursts last much longer than the previously proposed postmerger
energy-release time scales. Here, we show that they can be produced by
differentially rotating, millisecond pulsars after the mergers of binary neutron
stars. The differential rotation leads to windup of interior poloidal magnetic
fields and the resulting toroidal fields are strong enough to float up and break
through the stellar surface. Magnetic reconnection-driven explosive events then
occur, leading to multiple x-ray flares minutes after the original gamma-ray
burst.
PMID: 16497927 [PubMed]
9: Science. 2006 Feb 24;311(5764):1123-7.
Comment in:
Science. 2006 Feb 24;311(5764):1109-10.
A swimming mammaliaform from the Middle Jurassic and ecomorphological
diversification of early mammals.
Ji Q, Luo ZX, Yuan CX, Tabrum AR.
Department of Earth Science, Nanjing University, Nanjing 200017, China.
A docodontan mammaliaform from the Middle Jurassic of China possesses swimming
and burrowing skeletal adaptations and some dental features for aquatic feeding.
It is the most primitive taxon in the mammalian lineage known to have fur and
has a broad, flattened, partly scaly tail analogous to that of modern beavers.
We infer that docodontans were semiaquatic, convergent to the modern platypus
and many Cenozoic placentals. This fossil demonstrates that some mammaliaforms,
or proximal relatives to modern mammals, developed diverse locomotory and
feeding adaptations and were ecomorphologically different from the majority of
generalized small terrestrial Mesozoic mammalian insectivores.
PMID: 16497926 [PubMed - indexed for MEDLINE]
10: Science. 2006 Jan 27;311(5760):470; author reply 470.
Comment on:
Science. 2005 May 13;308(5724):996.
Comment on "Reconstructing the origin of Andaman islanders".
Palanichamy MG, Agrawal S, Yao YG, Kong QP, Sun C, Khan F, Chaudhuri TK, Zhang
YP.
Laboratory for Conservation and Utilization of Bio-resource, Yunnan University,
Kunming 650091, China.
On the basis of mitochondrial DNA sequence analyses, Thangaraj et al. (Brevia,
13 May 2005, p. 996) proposed that Andaman islanders descended from the first
humans to migrate out of Africa. We identified mitochondrial DNA from two
northeast Indian Rajbanshi individuals that shares three specific mutations with
the M31a lineage observed in the Great Andamanese, which suggests that the
predecessor of haplogroup M31 originated on the Indian subcontinent.
Publication Types:
Comment
PMID: 16439647 [PubMed - indexed for MEDLINE]
11: Science. 2006 Jan 6;311(5757):54-7. Epub 2005 Dec 8.
Comment in:
Science. 2006 Jan 6;311(5757):44-5.
The distance to the Perseus spiral arm in the Milky Way.
Xu Y, Reid MJ, Zheng XW, Menten KM.
Department of Astronomy, Nanjing University, Nanjing 210093, China.
We have measured the distance to the massive star-forming region W3OH in the
Perseus spiral arm of the Milky Way to be 1.95 +/- 0.04 kiloparsecs (5.86
x10(16) km). This distance was determined by triangulation, with Earth's orbit
as one segment of a triangle, using the Very Long Baseline Array. This resolves
the long-standing problem that there is a discrepancy of a factor of 2 between
different techniques used to determine distances. The reason for the discrepancy
is that this portion of the Perseus arm has anomalous motions. The orientation
of the anomalous motion agrees with spiral density-wave theory, but the
magnitude of the motion is somewhat larger than most models predict.
PMID: 16339410 [PubMed]
