Mutations in a human ROBO gene disrupt hindbrain axon pathway crossing and morphogenesis     

Jen JC  Chan WM  Bosley TM  Wan J  Carr JR  Rüb U  Shattuck D  Salamon G  Kudo LC  Ou J  Lin DD  Salih MA  Kansu T  Al Dhalaan H  Al Zayed Z  MacDonald DB  Stigsby B  Plaitakis A  Dretakis EK  Gottlob I  Pieh C  Traboulsi EI  Wang Q  Wang L  Andrews C  Yamada K  Demer JL  Karim S  Alger JR  Geschwind DH  Deller T  Sicotte NL  Nelson SF  Baloh RW  Engle EC 《Science (New York, N.Y.)》2004,304(5676):1509-1513

The mechanisms controlling axon guidance are of fundamental importance in understanding brain development. Growing corticospinal and somatosensory axons cross the midline in the medulla to reach their targets and thus form the basis of contralateral motor control and sensory input. The motor and sensory projections appeared uncrossed in patients with horizontal gaze palsy with progressive scoliosis (HGPPS). In patients affected with HGPPS, we identified mutations in the ROBO3 gene, which shares homology with roundabout genes important in axon guidance in developing Drosophila, zebrafish, and mouse. Like its murine homolog Rig1/Robo3, but unlike other Robo proteins, ROBO3 is required for hindbrain axon midline crossing.  相似文献   

Palladium-catalyzed aerobic dehydrogenation of substituted cyclohexanones to phenols     

Izawa Y  Pun D  Stahl SS 《Science (New York, N.Y.)》2011,333(6039):209-213

Aromatic molecules are key constituents of many pharmaceuticals, electronic materials, and commodity plastics. The utility of these molecules directly reflects the identity and pattern of substituents on the aromatic ring. Here, we report a palladium(II) catalyst system, incorporating an unconventional ortho-dimethylaminopyridine ligand, for the conversion of substituted cyclohexanones to the corresponding phenols. The reaction proceeds via successive dehydrogenation of two saturated carbon-carbon bonds of the six-membered ring and uses molecular oxygen as the hydrogen acceptor. This reactivity demonstrates a versatile and efficient strategy for the synthesis of substituted aromatic molecules with fundamentally different selectivity constraints from the numerous known synthetic methods that rely on substitution of a preexisting aromatic ring.  相似文献   

Patches with links: a unified system for processing faces in the macaque temporal lobe     

Moeller S  Freiwald WA  Tsao DY 《Science (New York, N.Y.)》2008,320(5881):1355-1359

The brain processes objects through a series of regions along the ventral visual pathway, but the circuitry subserving the analysis of specific complex forms remains unknown. One complex form category, faces, selectively activates six patches of cortex in the macaque ventral pathway. To identify the connectivity of these face patches, we used electrical microstimulation combined with simultaneous functional magnetic resonance imaging. Stimulation of each of four targeted face patches produced strong activation, specifically within a subset of the other face patches. Stimulation outside the face patches produced an activation pattern that spared the face patches. These results suggest that the face patches form a strongly and specifically interconnected hierarchical network.  相似文献   

Retraction     

Davis ST  Benson BG  Bramson HN  Chapman DE  Dickerson SH  Dold KM  Eberwein DJ  Edelstein M  Frye SV  Gampe RT  Grifffen RJ  Harris PA  Hassell AM  Holmes WD  Hunter RN  Knick VB  Lackey K  Lovejoy B  Luzzio MJ  Murray D  Parker P  Rocque WJ  Shewchuk-Chapman L  Veal JM  Walker DH  Kuyper LF 《Science (New York, N.Y.)》2002,298(5602):2327

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An assay to estimate tannins added to postmortem Turkey meat     

Lau DW  King AJ  Waterhouse AL 《Journal of agricultural and food chemistry》2003,51(23):6640-6644

A method for quantification of tannins in wine was adapted to determine tannins added to turkey meat. Standard curves containing varying amounts of GSE [0, 0.5, 1.0, 1.5, 2.0, 2.5, and 5.0%, (w/w)] as a source of tannins were developed. The R(2) value of the mean standard curve was 0.9992. The overall percent recovery of GSE in meat was determined to be 54.78%. Results showed that estimation of GSE in four out of five of the spiked samples was less than or equal to 10%. It is unclear as to why spiked samples at 0.048 mg of GSE were always underestimated (25.0%). Overall, the method seems applicable for estimation of tannins in poultry meat and is probably applicable to estimation of tannins in other meat products.  相似文献   

Resistenzeigenschaften im Gersten- und Weizensortiment Gatersleben 29. Prüfung von Gersten auf ihr Verhalten gegenüber dem Milden Gerstenmosaik-Virus (barley mild mosaic virus,BaMMV), Gerstengelbmosaik-Virus (barley yellow mosaic virus,BaYMV),Drechslera teres (Sacc.)Shoem. undPuccinia hordei Otth     

Gerhard Proeseler  Horst Hartleb  Doris Kopahnke  Christian O. Lehmann 《Genetic Resources and Crop Evolution》1989,37(2):145-154

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A cortical region consisting entirely of face-selective cells     

Tsao DY  Freiwald WA  Tootell RB  Livingstone MS 《Science (New York, N.Y.)》2006,311(5761):670-674

Face perception is a skill crucial to primates. In both humans and macaque monkeys, functional magnetic resonance imaging (fMRI) reveals a system of cortical regions that show increased blood flow when the subject views images of faces, compared with images of objects. However, the stimulus selectivity of single neurons within these fMRI-identified regions has not been studied. We used fMRI to identify and target the largest face-selective region in two macaques for single-unit recording. Almost all (97%) of the visually responsive neurons in this region were strongly face selective, indicating that a dedicated cortical area exists to support face processing in the macaque.  相似文献   

Dimethylsulfoniopropionate uptake by marine phytoplankton     

Vila-Costa M  Simó R  Harada H  Gasol JM  Slezak D  Kiene RP 《Science (New York, N.Y.)》2006,314(5799):652-654

Dimethylsulfoniopropionate (DMSP) accounts for most of the organic sulfur fluxes from primary to secondary producers in marine microbial food webs. Incubations of natural communities and axenic cultures with radio-labeled DMSP showed that dominant phytoplankton groups of the ocean, the unicellular cyanobacteria Prochlorococcus and Synechococcus and diatoms, as well as heterotrophic bacteria take up and assimilate DMSP sulfur, thus diverting a proportion of plankton-produced organic sulfur from emission into the atmosphere.  相似文献   

Impact of dopamine or dobutamine infusions on cardiovascular variables after rapid blood loss and volume replacement during isoflurane-induced anesthesia in dogs     

Dyson DH  Sinclair MD 《American journal of veterinary research》2006,67(7):1121-1130

OBJECTIVE: To determine the cardiovascular effects of dopamine and dobutamine infusions during nor-movolemia, hypovolemia (HV) through blood loss of 10 mL/kg (HV(10)), further loss to 25 mL/kg (HV(25)), and volume replacement (VR) in isoflurane-anesthetized dogs. ANIMALS: 7 healthy young dogs. PROCEDURES: Dogs were anesthetized with isoflurane 2 times (3 weeks apart). Cardiovascular measurements were obtained for each volume state. The cardiac index (CI) determined by the lithium dilution technique was compared with CI assessed by the arterial pulse contour technique. At each volume state, random treatment with dobutamine or dopamine was assessed (CI by the arterial pulse contour technique). Ten-minute treatments with 3 and 6 microg of dobutamine/kg/min or 7 and 14 microg of dopamine/kg/min (low and high doses, respectively) were administered sequentially. Differences from baseline were determined for volume, drug, and dose effects. RESULTS: Significant proportional changes in blood pressure (BP), stroke index (SI), and CI were evident with changes in volume state. Systemic vascular resistance (SVR) decreased after VR. Dobutamine induced little change in BP; increased heart rate (HR), SI, and CI; and decreased SVR (high dose). Dopamine increased BP and SI, did not change CI, and increased SVR (high dose). The arterial pulse contour technique underestimated changes in CI associated with volume changes. CONCLUSIONS AND CLINICAL RELEVANCE: Isoflurane eliminates clinically obvious compensatory increases in HR during HV. Dopamine is suitable for temporary management of blood loss in isoflurane-anesthetized dogs. Dobutamine increased CI without an associated improvement in BP. The arterial pulse contour monitor should be recalibrated when volume status changes.  相似文献   

Novel septoria speckled leaf blotch resistance loci in a barley doubled-haploid population     

Luckert D  Toubia-Rahme H  Steffenson BJ  Choo TM  Molnar SJ 《Phytopathology》2012,102(7):683-691

The genetics of resistance to Septoria speckled leaf blotch (SSLB), caused by Septoria passerinii, was studied in the Leger × CIho9831 barley doubled-haploid population. The 140 lines in the population segregated as 102 resistant and 38 susceptible, approximating a 3:1 ratio. A recombination map was developed using diversity arrays technology and other molecular markers. Quantitative trait locus (QTL) analysis demonstrated that resistance is primarily conferred either by having the CIho9831 allele at a QTL on 6HS or by having the CIho9831 allele at both of two QTLs on 3H and 2HL. In addition, ≈1/16 of the lines were resistant for unidentified reasons. This model predicts a resistant/susceptible ratio of 11:5, which fits the phenotypic observations. Minor QTLs were detected on 2HS and 1H. DNA sequences of linked markers suggest that the 6HS, 3H, and 2HS QTLs are part of resistance gene clusters and that the 6HS and 3H QTLs share homology. The 6HS QTL is identical to or closely linked to the SSLB resistance locus Rsp4 and the 1H QTL to the Rsp2 or Rsp3 locus. The 3H and 2HS QTLs are unique and offer new opportunities for pyramiding resistance genes through marker-assisted breeding for resistance to S. passerinii.  相似文献