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Sporrij A, Choudhuri A, Prasad M, Muhire B, Fast EM, Manning ME, Weiss JD, Koh M, Yang S, Kingston RE, Tolstorukov MY, Clevers H, Zon LI. PGE 2 alters chromatin through H2A.Z-variant enhancer nucleosome modification to promote hematopoietic stem cell fate. Proc Natl Acad Sci U S A 2023; 120:e2220613120. [PMID: 37126722 PMCID: PMC10175842 DOI: 10.1073/pnas.2220613120] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2022] [Accepted: 03/13/2023] [Indexed: 05/03/2023] Open
Abstract
Prostaglandin E2 (PGE2) and 16,16-dimethyl-PGE2 (dmPGE2) are important regulators of hematopoietic stem and progenitor cell (HSPC) fate and offer potential to enhance stem cell therapies [C. Cutler et al. Blood 122, 3074-3081(2013); W. Goessling et al. Cell Stem Cell 8, 445-458 (2011); W. Goessling et al. Cell 136, 1136-1147 (2009)]. Here, we report that PGE2-induced changes in chromatin at enhancer regions through histone-variant H2A.Z permit acute inflammatory gene induction to promote HSPC fate. We found that dmPGE2-inducible enhancers retain MNase-accessible, H2A.Z-variant nucleosomes permissive of CREB transcription factor (TF) binding. CREB binding to enhancer nucleosomes following dmPGE2 stimulation is concomitant with deposition of histone acetyltransferases p300 and Tip60 on chromatin. Subsequent H2A.Z acetylation improves chromatin accessibility at stimuli-responsive enhancers. Our findings support a model where histone-variant nucleosomes retained within inducible enhancers facilitate TF binding. Histone-variant acetylation by TF-associated nucleosome remodelers creates the accessible nucleosome landscape required for immediate enhancer activation and gene induction. Our work provides a mechanism through which inflammatory mediators, such as dmPGE2, lead to acute transcriptional changes and modify HSPC behavior to improve stem cell transplantation.
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Affiliation(s)
- Audrey Sporrij
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA02138
- Stem Cell Program and Division of Hematology/Oncology, Boston Children’s Hospital, Boston, MA02115
| | - Avik Choudhuri
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA02138
- Stem Cell Program and Division of Hematology/Oncology, Boston Children’s Hospital, Boston, MA02115
| | - Meera Prasad
- Stem Cell Program and Division of Hematology/Oncology, Boston Children’s Hospital, Boston, MA02115
| | - Brejnev Muhire
- Department of Molecular Biology, Massachusetts General Hospital and Harvard Medical School, Boston, MA02114
| | - Eva M. Fast
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA02138
- Stem Cell Program and Division of Hematology/Oncology, Boston Children’s Hospital, Boston, MA02115
| | - Margot E. Manning
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA02138
- Stem Cell Program and Division of Hematology/Oncology, Boston Children’s Hospital, Boston, MA02115
| | - Jodi D. Weiss
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA02138
- Stem Cell Program and Division of Hematology/Oncology, Boston Children’s Hospital, Boston, MA02115
| | - Michelle Koh
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA02138
- Stem Cell Program and Division of Hematology/Oncology, Boston Children’s Hospital, Boston, MA02115
| | - Song Yang
- Stem Cell Program and Division of Hematology/Oncology, Boston Children’s Hospital, Boston, MA02115
| | - Robert E. Kingston
- Department of Molecular Biology, Massachusetts General Hospital and Harvard Medical School, Boston, MA02114
| | | | - Hans Clevers
- Oncode Institute, Hubrecht Institute, Royal Netherlands Academy of Arts and Sciences and University Medical Center Utrecht, Utrecht3584 CT, The Netherlands
- Princess Máxima Center for Pediatric Oncology, Utrecht3584 CS, The Netherlands
| | - Leonard I. Zon
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA02138
- Stem Cell Program and Division of Hematology/Oncology, Boston Children’s Hospital, Boston, MA02115
- HHMI, Harvard Stem Cell Institute, Boston, MA02115
- Harvard Medical School, Harvard Stem Cell Institute, Boston, MA02115
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Weiss JD, McVey SL, Stinebaugh SE, Sullivan CF, Dawe RK, Nannas NJ. Frequent Spindle Assembly Errors Require Structural Rearrangement to Complete Meiosis in Zea mays. Int J Mol Sci 2022; 23:ijms23084293. [PMID: 35457112 PMCID: PMC9031645 DOI: 10.3390/ijms23084293] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Revised: 04/01/2022] [Accepted: 04/05/2022] [Indexed: 12/04/2022] Open
Abstract
The success of an organism is contingent upon its ability to faithfully pass on its genetic material. In the meiosis of many species, the process of chromosome segregation requires that bipolar spindles be formed without the aid of dedicated microtubule organizing centers, such as centrosomes. Here, we describe detailed analyses of acentrosomal spindle assembly and disassembly in time-lapse images, from live meiotic cells of Zea mays. Microtubules organized on the nuclear envelope with a perinuclear ring structure until nuclear envelope breakdown, at which point microtubules began bundling into a bipolar form. However, the process and timing of spindle assembly was highly variable, with frequent assembly errors in both meiosis I and II. Approximately 61% of cells formed incorrect spindle morphologies, with the most prevalent being tripolar spindles. The erroneous spindles were actively rearranged to bipolar through a coalescence of poles before proceeding to anaphase. Spindle disassembly occurred as a two-state process with a slow depolymerization, followed by a quick collapse. The results demonstrate that maize meiosis I and II spindle assembly is remarkably fluid in the early assembly stages, but otherwise proceeds through a predictable series of events.
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Affiliation(s)
- Jodi D. Weiss
- Department of Biology, Hamilton College, Clinton, NY 13323, USA; (J.D.W.); (S.L.M.); (S.E.S.); (C.F.S.)
| | - Shelby L. McVey
- Department of Biology, Hamilton College, Clinton, NY 13323, USA; (J.D.W.); (S.L.M.); (S.E.S.); (C.F.S.)
| | - Sarah E. Stinebaugh
- Department of Biology, Hamilton College, Clinton, NY 13323, USA; (J.D.W.); (S.L.M.); (S.E.S.); (C.F.S.)
| | - Caroline F. Sullivan
- Department of Biology, Hamilton College, Clinton, NY 13323, USA; (J.D.W.); (S.L.M.); (S.E.S.); (C.F.S.)
| | - R. Kelly Dawe
- Department of Genetics, University of Georgia, Athens, GA 30602, USA;
- Department of Plant Biology, University of Georgia, Athens, GA 30602, USA
| | - Natalie J. Nannas
- Department of Biology, Hamilton College, Clinton, NY 13323, USA; (J.D.W.); (S.L.M.); (S.E.S.); (C.F.S.)
- Correspondence:
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Greer CB, Wright J, Weiss JD, Lazarenko RM, Moran SP, Zhu J, Chronister KS, Jin AY, Kennedy AJ, Sweatt JD, Kaas GA. Tet1 Isoforms Differentially Regulate Gene Expression, Synaptic Transmission, and Memory in the Mammalian Brain. J Neurosci 2021; 41:578-593. [PMID: 33262245 PMCID: PMC7842754 DOI: 10.1523/jneurosci.1821-20.2020] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Revised: 09/28/2020] [Accepted: 11/02/2020] [Indexed: 12/22/2022] Open
Abstract
The dynamic regulation of DNA methylation in postmitotic neurons is necessary for memory formation and other adaptive behaviors. Ten-eleven translocation 1 (TET1) plays a part in these processes by oxidizing 5-methylcytosine (5mC) to 5-hydroxymethylcytosine (5hmC), thereby initiating active DNA demethylation. However, attempts to pinpoint its exact role in the nervous system have been hindered by contradictory findings, perhaps due in part, to a recent discovery that two isoforms of the Tet1 gene are differentially expressed from early development into adulthood. Here, we demonstrate that both the shorter transcript (Tet1S ) encoding an N-terminally truncated TET1 protein and a full-length Tet1 (Tet1FL ) transcript encoding canonical TET1 are co-expressed in the adult mouse brain. We show that Tet1S is the predominantly expressed isoform and is highly enriched in neurons, whereas Tet1FL is generally expressed at lower levels and more abundant in glia, suggesting their roles are at least partially cell type-specific. Using viral-mediated, isoform and neuron-specific molecular tools, we find that the individual repression of each transcript leads to the dysregulation of unique gene ensembles and contrasting changes in basal synaptic transmission. In addition, Tet1S repression enhances, while Tet1FL impairs, hippocampal-dependent memory in male mice. Together, our findings demonstrate that each Tet1 isoform serves a distinct role in the mammalian brain.SIGNIFICANCE STATEMENT In the brain, activity-dependent changes in gene expression are required for the formation of long-term memories. DNA methylation plays an essential role in orchestrating these learning-induced transcriptional programs by influencing chromatin accessibility and transcription factor binding. Once thought of as a stable epigenetic mark, DNA methylation is now known to be impermanent and dynamically regulated, driving neuroplasticity in the brain. We found that Tet1, a member of the ten-eleven translocation (TET) family of enzymes that mediates removal of DNA methyl marks, is expressed as two separate isoforms in the adult mouse brain and that each differentially regulates gene expression, synaptic transmission and memory formation. Together, our findings demonstrate that each Tet1 isoform serves a distinct role in the CNS.
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Affiliation(s)
- C B Greer
- Department of Pharmacology, Vanderbilt University, Nashville, Tennessee 37232
| | - J Wright
- Department of Pharmacology, Vanderbilt University, Nashville, Tennessee 37232
| | - J D Weiss
- Department of Pharmacology, Vanderbilt University, Nashville, Tennessee 37232
| | - R M Lazarenko
- Department of Pharmacology, Vanderbilt University, Nashville, Tennessee 37232
| | - S P Moran
- Department of Pharmacology, Vanderbilt University, Nashville, Tennessee 37232
| | - J Zhu
- Department of Pharmacology, Vanderbilt University, Nashville, Tennessee 37232
| | - K S Chronister
- Department of Pharmacology, Vanderbilt University, Nashville, Tennessee 37232
| | - A Y Jin
- Department of Pharmacology, Vanderbilt University, Nashville, Tennessee 37232
| | - A J Kennedy
- Department of Chemistry, Bates College, Lewiston, Maine 04240
| | - J D Sweatt
- Department of Pharmacology, Vanderbilt University, Nashville, Tennessee 37232
| | - G A Kaas
- Department of Pharmacology, Vanderbilt University, Nashville, Tennessee 37232
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Lee S, Tarantini C, Gao P, Jiang J, Weiss JD, Kametani F, Folkman CM, Zhang Y, Pan XQ, Hellstrom EE, Larbalestier DC, Eom CB. Artificially engineered superlattices of pnictide superconductors. Nat Mater 2013; 12:392-396. [PMID: 23455850 DOI: 10.1038/nmat3575] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2012] [Accepted: 01/25/2013] [Indexed: 06/01/2023]
Abstract
Significant progress has been achieved in fabricating high-quality bulk and thin-film iron-based superconductors. In particular, artificial layered pnictide superlattices offer the possibility of tailoring the superconducting properties and understanding the mechanism of the superconductivity itself. For high-field applications, large critical current densities (J(c)) and irreversibility fields (H(irr)) are indispensable along all crystal directions. On the other hand, the development of superconducting devices such as tunnel junctions requires multilayered heterostructures. Here we show that artificially engineered undoped Ba-122/Co-doped Ba-122 compositionally modulated superlattices produce ab-aligned nanoparticle arrays. These layer and self-assemble along c-axis-aligned defects, and combine to produce very large J(c) and H(irr) enhancements over a wide angular range. We also demonstrate a structurally modulated SrTiO3(STO)/Co-doped Ba-122 superlattice with sharp interfaces. Success in superlattice fabrication involving pnictides will aid the progress of heterostructured systems exhibiting new interfacial phenomena and device applications.
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Weiss JD, Tarantini C, Jiang J, Kametani F, Polyanskii AA, Larbalestier DC, Hellstrom EE. High intergrain critical current density in fine-grain (Ba0.6K0.4)Fe2As2 wires and bulks. Nat Mater 2012; 11:682-685. [PMID: 22635041 DOI: 10.1038/nmat3333] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2012] [Accepted: 04/17/2012] [Indexed: 06/01/2023]
Abstract
The K- and Co-doped BaFe(2)As(2) (Ba-122) superconducting compounds are potentially useful for applications because they have upper critical fields (H(c2)) of well over 50 T, H(c2) anisotropy γ < 2and thin-film critical current densities J(c) exceeding 1 MA cm(-2) (refs 1-4) at 4.2 K. However, thin-film bicrystals of Co-doped Ba-122 clearly exhibit weak link behaviour for [001] tilt misorientations of more than about 5°, suggesting that textured substrates would be needed for applications, as in the cuprates. Here we present a contrary and very much more positive result in which untextured polycrystalline (Ba(0.6)K(0.4))Fe(2)As(2) bulks and round wires with high grain boundary density have transport critical current densities well over 0.1 MA cm(-2) (self-field, 4.2 K), more than 10 times higher than that of any other round untextured ferropnictide wire and 4-5 times higher than the best textured flat wire. The enhanced grain connectivity is ascribed to their much improved phase purity and to the enhanced vortex stiffness of this low-anisotropy compound (γ~1-2) when compared with YBa(2)Cu(3)O(7-x) (γ~5).
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Affiliation(s)
- J D Weiss
- Applied Superconductivity Center, National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32310, USA
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Tortello M, Daghero D, Ummarino GA, Stepanov VA, Jiang J, Weiss JD, Hellstrom EE, Gonnelli RS. Multigap superconductivity and strong electron-boson coupling in Fe-based superconductors: a point-contact Andreev-reflection study of Ba(Fe(1-x)Co(x))2As2 single crystals. Phys Rev Lett 2010; 105:237002. [PMID: 21231497 DOI: 10.1103/physrevlett.105.237002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2010] [Indexed: 05/30/2023]
Abstract
Directional point-contact Andreev-reflection measurements in Ba(Fe(1-x)Co(x))2As2 single crystals (T(c) = 24.5 K) indicate the presence of two superconducting gaps with no line nodes on the Fermi surface. The point-contact Andreev-reflection spectra also feature additional structures related to the electron-boson interaction, from which the characteristic boson energy Ω(b)(T) is obtained, very similar to the spin-resonance energy observed in neutron scattering experiments. Both the gaps and the additional structures can be reproduced within a three-band s ± Eliashberg model by using an electron-boson spectral function peaked at Ω(0) = 12 meV ≃ Ω(b)(0).
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Affiliation(s)
- M Tortello
- Dipartimento di Fisica, Politecnico di Torino, 10129 Torino, Italy
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7
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Sheet G, Mehta M, Dikin DA, Lee S, Bark CW, Jiang J, Weiss JD, Hellstrom EE, Rzchowski MS, Eom CB, Chandrasekhar V. Phase-incoherent superconducting pairs in the normal state of Ba(Fe(1-x)Co(x))₂As₂. Phys Rev Lett 2010; 105:167003. [PMID: 21230998 DOI: 10.1103/physrevlett.105.167003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2010] [Indexed: 05/30/2023]
Abstract
The normal state properties of the recently discovered ferropnictide superconductors might hold the key to understanding their exotic superconductivity. Using point-contact spectroscopy we show that Andreev reflection between an epitaxial thin film of Ba(Fe(0.92)Co(0.08))₂As₂ and a silver tip can be seen in the normal state of the film up to temperature T∼1.3T(c), where T(c) is the critical temperature of the superconductor. Andreev reflection far above T(c) can be understood only when superconducting pairs arising from strong fluctuation of the phase of the complex superconducting order parameter exist in the normal state. Our results provide spectroscopic evidence of phase-incoherent superconducting pairs in the normal state of the ferropnictide superconductors.
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Affiliation(s)
- Goutam Sheet
- Department of Physics and Astronomy, Northwestern University, Evanston, Illinois 60208, USA.
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Lee S, Jiang J, Zhang Y, Bark CW, Weiss JD, Tarantini C, Nelson CT, Jang HW, Folkman CM, Baek SH, Polyanskii A, Abraimov D, Yamamoto A, Park JW, Pan XQ, Hellstrom EE, Larbalestier DC, Eom CB. Template engineering of Co-doped BaFe2As2 single-crystal thin films. Nat Mater 2010; 9:397-402. [PMID: 20190768 DOI: 10.1038/nmat2721] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2009] [Accepted: 02/05/2010] [Indexed: 05/28/2023]
Abstract
Understanding new superconductors requires high-quality epitaxial thin films to explore intrinsic electromagnetic properties and evaluate device applications. So far, superconducting properties of ferropnictide thin films seem compromised by imperfect epitaxial growth and poor connectivity of the superconducting phase. Here we report new template engineering using single-crystal intermediate layers of (001) SrTiO(3) and BaTiO(3) grown on various perovskite substrates that enables genuine epitaxial films of Co-doped BaFe(2)As(2) with a high transition temperature (T(c,rho=0) of 21.5 K, where rho=resistivity), a small transition width (DeltaT(c)=1.3 K), a superior critical current density J(c) of 4.5 MA cm(-2) (4.2 K) and strong c-axis flux pinning. Implementing SrTiO(3) or BaTiO(3) templates to match the alkaline-earth layer in the Ba-122 with the alkaline-earth/oxygen layer in the templates opens new avenues for epitaxial growth of ferropnictides on multifunctional single-crystal substrates. Beyond superconductors, it provides a framework for growing heteroepitaxial intermetallic compounds on various substrates by matching interfacial layers between templates and thin-film overlayers.
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Affiliation(s)
- S Lee
- Department of Materials Science and Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
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Train JS, Ross H, Weiss JD, Feingold ML, Khoury-Yacoub A, Khoury PT. Mesenteric venous thrombosis: successful treatment by intraarterial lytic therapy. J Vasc Interv Radiol 1998; 9:461-4. [PMID: 9618106 DOI: 10.1016/s1051-0443(98)70299-4] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Affiliation(s)
- J S Train
- Department of Radiology, White Plains Hospital Center, NY 10601, USA
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Lovett SM, Weiss JD, Diogo MJ, Williams PT, Garite TJ. A prospective, double-blind, randomized, controlled clinical trial of ampicillin-sulbactam for preterm premature rupture of membranes in women receiving antenatal corticosteroid therapy. Am J Obstet Gynecol 1997; 176:1030-8. [PMID: 9166164 DOI: 10.1016/s0002-9378(97)70398-3] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
OBJECTIVE Our purpose was to test the efficacy of antibiotic prophylaxis in women with preterm premature rupture of the membranes who receive antenatal corticosteroids. STUDY DESIGN A total of 112 women received one of three regimens in a double-blind randomized controlled trial: (1) ampicillin-sulbactam for 72 hours followed by amoxicillin-clavulanate, (2) ampicillin for 72 hours followed by amoxicillin, or (3) placebo. RESULTS A total of 48.6% of neonates in the placebo group either died or had sepsis or respiratory distress syndrome versus 29.3% in the pooled antibiotic group (p < 0.05) and 26.3% in the ampicillin-sulbactam/amoxicillin-clavulanate subgroup (p < 0.05). All three neonatal deaths occurred in the placebo group (p = 0.03 versus pooled antibiotics). Mean birth weight was significantly greater in the pooled antibiotic group (1773 gm, p = 0.04) and in the ampicillin-sulbactam/amoxicillin-clavulanate subgroup (1870 gm, p = 0.02) than in the placebo group (1543 gm). Antibiotic prophylaxis reduced the need for prolonged ventilation (p = 0.05). CONCLUSIONS Antibiotic prophylaxis in combination with corticosteroids in preterm premature rupture of membranes significantly lowered the total frequency of neonatal mortality, sepsis, and respiratory distress syndrome and significantly increased birth weight compared with corticosteroids alone.
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Affiliation(s)
- S M Lovett
- East Bay Perinatal Medical Associates, Oakland, CA 94609, USA
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11
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Weiss JD, Stoever JH. Vacuum feedthrough for optical fiber cables. Appl Opt 1985; 24:165269. [PMID: 20440336 DOI: 10.1364/ao.24.2755_1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
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12
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Weiss JD. Piezooptic behavior of certain fluids. Appl Opt 1985; 24:1151. [PMID: 18217090 DOI: 10.1364/ao.24.001151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
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13
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Weiss JD. Frequency response of the atmosphere under thermal blooming conditions. Appl Opt 1982; 21:2253-2261. [PMID: 20396013 DOI: 10.1364/ao.21.002253] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
An analysis, using a single-phase-sheet model, of the effect of an oscillating thermally bloomed atmosphere on a high-power laser beam is presented. The oscillations are caused by a small modulation of the wave front of the beam at the transmitter. The primary contention made here is that the time-dependent blooming is not an oscillating version of its static counterpart; rather, new gratinglike effects are introduced by the interaction of the crosswind and the dithered high-power beam. The resulting temporal variations of the target-plane irradiance at the position of its static bloomed peak are examined and implications for slow dither are discussed.
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Affiliation(s)
- J D Weiss
- Sandia National Laboratories, Albuquerque, New Mexico 87185, USA
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14
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Weiss JD. Thermal blooming in a diagonal wind. Appl Opt 1980; 19:2268. [PMID: 20234405 DOI: 10.1364/ao.19.002268] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
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Weiss JD, Maclnnis WH. Thermal blooming: round beam vs square beam. Appl Opt 1980; 19:31-33. [PMID: 20216790 DOI: 10.1364/ao.19.000031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
We have examined Fried's suggestion that an initially square high-power laser beam will experience significantly less thermal blooming than a round beam. In almost every case of interest the computer results were the opposite of what he suggested, indicating the importance, and rather unintuitive nature, of diffraction.
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