scispace - formally typeset
Search or ask a question
Institution

California Institute of Technology

EducationPasadena, California, United States
About: California Institute of Technology is a education organization based out in Pasadena, California, United States. It is known for research contribution in the topics: Galaxy & Population. The organization has 57649 authors who have published 146691 publications receiving 8620287 citations. The organization is also known as: Caltech & Cal Tech.


Papers
More filters
Journal ArticleDOI
TL;DR: Genetic mosaics show that the cells of each ommatidium are not derived from a single mother cell; the cells appear to be recruited at random at the morphogenetic front.

996 citations

Journal ArticleDOI
16 Nov 2007-Science
TL;DR: A design strategy is introduced that allows a specified input oligonucleotide to catalyze the release of a specified output oligon nucleotide, which in turn can serve as a catalyst for other reactions, which provides an amplifying circuit element that is simple, fast, modular, composable, and robust.
Abstract: Artificial biochemical circuits are likely to play as large a role in biological engineering as electrical circuits have played in the engineering of electromechanical devices. Toward that end, nucleic acids provide a designable substrate for the regulation of biochemical reactions. However, it has been difficult to incorporate signal amplification components. We introduce a design strategy that allows a specified input oligonucleotide to catalyze the release of a specified output oligonucleotide, which in turn can serve as a catalyst for other reactions. This reaction, which is driven forward by the configurational entropy of the released molecule, provides an amplifying circuit element that is simple, fast, modular, composable, and robust. We have constructed and characterized several circuits that amplify nucleic acid signals, including a feedforward cascade with quadratic kinetics and a positive feedback circuit with exponential growth kinetics.

995 citations

Journal ArticleDOI
TL;DR: The photochemistry of simple molecules containing carbon, hydrogen, nitrogen, and oxygen atoms in the atmosphere of Titan has been investigated using updated chemical schemes and the authors' own estimates of a number of key rate coefficients, which satisfactorily accounts for the concentrations of minor species observed by the Voyager IRIS and UVS instruments.
Abstract: The photochemistry of simple molecules containing carbon, hydrogen, nitrogen, and oxygen atoms in the atmosphere of Titan has been investigated using updated chemical schemes and our own estimates of a number of key rate coefficients. Proper exospheric boundary conditions, vertical transport, and condensation processes at the tropopause have been incorporated into the model. It is argued that the composition, climatology, and evolution of Titan's atmosphere are controlled by five major processes: (a) photolysis and photosensitized dissociation of CH_4 ; (b) conversion of H to H_2 and escape of hydrogen; (c) synthesis of higher hydrocarbons; (d) coupling between nitrogen and hydrocarbons; (e) coupling between oxygen and hydrocarbons. Starting with N_2, CH_4, and H_20, and invoking interactions with ultraviolet sunlight, energetic electrons, and cosmic rays, the model satisfactorily accounts for the concentrations of minor species observed by the Voyager IRIS and UVS instruments. Photochemistry is responsible for converting the simpler atmospheric species into more complex organic compounds, which are subsequently condensed at the tropopause and deposited on the surface. Titan might have lost 5.6 × 10^4 , 1.8 × 10^3, and 4.0 g cm^-2 , or the equivalent of 8,0.25, and 5 × 10^-4 bars of CH_4, N_2 , and CO, respectively, over geologic time. Implications of abiotic organic synthesis on Titan for the origin of life on Earth are briefly discussed.

994 citations

Journal ArticleDOI
TL;DR: In this paper, it was shown that the process of evaporation and diffusion of water vapor from any water surface into the body of air above it is exactly similar to that of the conduction or diffusion of specific heat energy from the water surface to the same body of water.
Abstract: It is shown that the process of evaporation and diffusion of water vapor from any water surface into the body of air above it is exactly similar to that of the conduction or "diffusion" of specific heat energy from the water surface into the same body of air. Because of this similarity it is possible to represent the ratio R of the heat loss by conduction to that by evaporation by the formula R=.46Tw-Ta/Pw-PaP/760 where Ta and Pa are the original temperature and vapor pressure of the air passing over the lake, and Tw and Pw are the corresponding quantities for the layer of air in contact with the water surface. The substitution of R times the evaporation loss for the value of the conduction heat loss in the Cummings equation for evaporation makes it an exact equation for the determination of evaporation from any water surface in terms of the net radiant energy absorbed by the water and the heat stored in the water.

993 citations

Journal ArticleDOI
TL;DR: In this article, the authors estimate the galaxy stellar mass function and stellar mass density for star-forming and quiescent galaxies with 0.2 − 1.5 consistent with the expected uncertainties.
Abstract: We estimate the galaxy stellar mass function and stellar mass density for star-forming and quiescent galaxies with 0.2 1.5 consistent with the expected uncertainties. We also develop a new method to infer the specific star formation rate from the mass function of star-forming galaxies. We find that the specific star formation rate of 1010 − 10.5ℳ⊙ galaxies increases continuously in the redshift range 1 < z < 4. Finally, we compare our results with a semi-analytical model and find that these models overestimate the density of low mass quiescent galaxies by an order of magnitude, while the density of low-mass star-forming galaxies is successfully reproduced.

992 citations


Authors

Showing all 58155 results

NameH-indexPapersCitations
Eric S. Lander301826525976
Donald P. Schneider2421622263641
George M. Whitesides2401739269833
Yi Chen2174342293080
David Baltimore203876162955
Edward Witten202602204199
George Efstathiou187637156228
Michael A. Strauss1851688208506
Jing Wang1844046202769
Ruedi Aebersold182879141881
Douglas Scott1781111185229
Hyun-Chul Kim1764076183227
Phillip A. Sharp172614117126
Timothy M. Heckman170754141237
Zhenan Bao169865106571
Network Information
Related Institutions (5)
Massachusetts Institute of Technology
268K papers, 18.2M citations

95% related

Princeton University
146.7K papers, 9.1M citations

94% related

Max Planck Society
406.2K papers, 19.5M citations

93% related

University of California, Berkeley
265.6K papers, 16.8M citations

93% related

Centre national de la recherche scientifique
382.4K papers, 13.6M citations

93% related

Performance
Metrics
No. of papers from the Institution in previous years
YearPapers
2023176
2022737
20214,682
20205,519
20195,321
20185,133