Discovery of intense gamma-ray flashes of atmospheric origin   总被引：1，自引：0，他引：1  

Fishman GJ  Bhat PN  Mallozzi R  Horack JM  Koshut T  Kouveliotou C  Pendleton GN  Meegan CA  Wilson RB  Paciesas WS  Goodman SJ  Christian HJ 《Science (New York, N.Y.)》1994,264(5163):1313-1316

Detectors aboard the Compton Gamma Ray Observatory have observed an unexplained terrestrial phenomenon: brief, intense flashes of gamma rays. These flashes must originate in the atmosphere at altitudes above at least 30 kilometers in order to escape atmospheric absorption and reach the orbiting detectors. At least a dozen such events have been detected over the past 2 years. The photon spectra from the events are very hard (peaking in the high-energy portion of the spectrum) and are consistent with bremsstrahlung emission from energetic (million-electron volt) electrons. The most likely origin of these high-energy electrons, although speculative at this time, is a rare type of high-altitude electrical discharge above thunderstorm regions.  相似文献   

Phylogenetic relations of humans and African apes from DNA sequences in the psi eta-globin region   总被引：17，自引：0，他引：17  

M M Miyamoto  J L Slightom  M Goodman 《Science (New York, N.Y.)》1987,238(4825):369-373

Sequences from the upstream and downstream flanking DNA regions of the psi eta-globin locus in Pan troglodytes (common chimpanzee), Gorilla gorilla (gorilla), and Pongo pygmaeus (orangutan, the closest living relative to Homo, Pan, and Gorilla) provided further data for evaluating the phylogenetic relations of humans and African apes. These newly sequenced orthologs [an additional 4.9 kilobase pairs (kbp) for each species] were combined with published psi eta-gene sequences and then compared to the same orthologous stretch (a continuous 7.1-kbp region) available for humans. Phylogenetic analysis of these nucleotide sequences by the parsimony method indicated (i) that human and chimpanzee are more closely related to each other than either is to gorilla and (ii) that the slowdown in the rate of sequence evolution evident in higher primates is especially pronounced in humans. These results indicate that features (for example, knuckle-walking) unique to African apes (but not to humans) are primitive and that even local molecular clocks should be applied with caution.  相似文献   

Implantation of genetically engineered fibroblasts into mice: implications for gene therapy   总被引：7，自引：0，他引：7  

R F Selden  M J Skoskiewicz  K B Howie  P S Russell  H M Goodman 《Science (New York, N.Y.)》1987,236(4802):714-718

In a variety of human genetic diseases, replacement of the absent or defective protein provides significant therapeutic benefits. As a model for a somatic cell gene therapy system, cultured murine fibroblasts were transfected with a human growth hormone (hGH) fusion gene and cells from one of the resulting clonal lines were subsequently implanted into various locations in mice. Such implants synthesized and secreted hGH, which was detectable in the serum. The function of the implants depended on their location and size, and on the histocompatibility of the donor cells with their recipients. The expression of hGH could be modified by addition of regulatory effectors, and, with appropriate immunosuppression, the implants survived for more than 3 months. This approach to gene therapy, here termed "transkaryotic implantation," is potentially applicable to many genetic diseases in that the transfected cell line can be extensively characterized prior to implantation, several anatomical sites are suitable for implantation, and regulated expression of the gene of therapeutic interest can be obtained.  相似文献   

A simple model for neutrino cooling of the large magellanic cloud supernova     

Spergel DN  Piran T  Loeb A  Goodman J  Bahcall JN 《Science (New York, N.Y.)》1987,237(4821):1471-1473

A simplified analytic model of a cooling hot neutron star, motivated by detailed computer calculations, describes well the neutrinos detected from the recent supernova in the Large Magellanic Cloud. The observations do not require explanations that invoke exotic physics or complicated astrophysics. The parameters in this simple model are not severely constrained: 6.1(-3.6)(+3.5) x 10(52) ergs emitted in electron antineutrinos, a peak temperature of 4.2(-0.8)(+1.2) megaelectron volts, a radius of 27(-15)(+17) kilometers, and a cooling time of 4.5(-2.0)(+1.7) seconds.  相似文献   

Expression and function of the segmentation gene fushi tarazu during Drosophila neurogenesis   总被引：33，自引：0，他引：33  

C Q Doe  Y Hiromi  W J Gehring  C S Goodman 《Science (New York, N.Y.)》1988,239(4836):170-175

Segmentation genes control cell identities during early pattern formation in Drosophila. One of these genes, fushi tarazu (ftz), is now shown also to control cell fate during neurogenesis. Early in development, ftz is expressed in a striped pattern at the blastoderm stage. Later, it is transiently expressed in a specific subset of neuronal precursor cells, neurons (such as aCC, pCC, RP1, and RP2), and glia in the developing central nervous system (CNS). The function of ftz in the CNS was determined by creating ftz mutant embryos that express ftz in the blastoderm stripes but not in the CNS. In the absence of ftz CNS expression, some neurons appear normal (for example, the aCC, pCC, and RP1), whereas the RP2 neuron extends its growth cone along an abnormal pathway, mimicking its sibling (RP1), suggesting a transformation in neuronal identity.  相似文献   

Undergraduate research. Genomics Education Partnership     

Lopatto D  Alvarez C  Barnard D  Chandrasekaran C  Chung HM  Du C  Eckdahl T  Goodman AL  Hauser C  Jones CJ  Kopp OR  Kuleck GA  McNeil G  Morris R  Myka JL  Nagengast A  Overvoorde PJ  Poet JL  Reed K  Regisford G  Revie D  Rosenwald A  Saville K  Shaw M  Skuse GR  Smith C  Smith M  Spratt M  Stamm J  Thompson JS  Wilson BA  Witkowski C  Youngblom J  Leung W  Shaffer CD  Buhler J  Mardis E  Elgin SC 《Science (New York, N.Y.)》2008,322(5902):684-685

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Gonadotroph-specific expression of metallothionein fusion genes in pituitaries of transgenic mice   总被引：4，自引：0，他引：4  

M J Low  R M Lechan  R E Hammer  R L Brinster  J F Habener  G Mandel  R H Goodman 《Science (New York, N.Y.)》1986,231(4741):1002-1004

Transgenic mice expressing a metallothionein-somatostatin fusion gene contain high concentrations of somatostatin in the anterior pituitary gland, a tissue that does not normally produce somatostatin. Immunoreactive somatostatin within the anterior pituitaries was found exclusively within gonadotrophs. Similarly, a metallothionein-human growth-hormone fusion gene was also expressed selectively in gonadotrophs. It is proposed that sequences common to the two fusion genes are responsible for the gonadotroph-specific expression.  相似文献   

Immunogenicity of glucagon: determinants responsible for antibody binding and lymphocyte stimulation   总被引：4，自引：0，他引：4  

G Senyk  D Nitecki  J W Goodman 《Science (New York, N.Y.)》1971,171(969):407-408

Bovine glucagon, a polypeptide of 29 amino acids, is immunogenic in rabbits and guinea pigs. The antigenic determinants of glucagon were investigated with isolated tryptic peptides of the hormone. Antibodies from virtually all of more than a dozen animals tested had specificity primarily for the aminoterminal heptadecapeptide. However, only intact glucagon and its carboxy-terminal dodecapeptide stimulated spleen or lymph node cells to synthesize DNA. It thus appears that glucagon was cleaved along functional lines into two parts, one of which contained the major antigenic determinant for serum antibody and the other of which was "recognized" by antigen-reactive cells.  相似文献   

Eppendorf essay winner. Deconstructing C. elegans sensory mechanotransduction     

Goodman MB 《Science (New York, N.Y.)》2004,306(5695):427-428

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Coherin: a new peptide of the bovine neurohypophysis with activity on gastrointestinal motility   总被引：1，自引：0，他引：1  

I Goodman  R B Hiatt 《Science (New York, N.Y.)》1972,178(59):419-421

A factor with potent activity in the regulation of mammalian gastrointestinal motor function has been isolated from the bovine posterior pituitary gland by a process allowing minimal dissociation of neurophysin-bound complexes and the separation of free unbound peptides. This substance alters the frequency, amplitude, rhythm, and duration of peristaltic contraction.  相似文献