23 results
Agricultural Research Service Weed Science Research: Past, Present, and Future
- Stephen L. Young, James V. Anderson, Scott R. Baerson, Joanna Bajsa-Hirschel, Dana M. Blumenthal, Chad S. Boyd, Clyde D. Boyette, Eric B. Brennan, Charles L. Cantrell, Wun S. Chao, Joanne C. Chee-Sanford, Charlie D. Clements, F. Allen Dray, Stephen O. Duke, Kayla M. Eason, Reginald S. Fletcher, Michael R. Fulcher, John F. Gaskin, Brenda J. Grewell, Erik P. Hamerlynck, Robert E. Hoagland, David P. Horvath, Eugene P. Law, John D. Madsen, Daniel E. Martin, Clint Mattox, Steven B. Mirsky, William T. Molin, Patrick J. Moran, Rebecca C. Mueller, Vijay K. Nandula, Beth A. Newingham, Zhiqiang Pan, Lauren M. Porensky, Paul D. Pratt, Andrew J. Price, Brian G. Rector, Krishna N. Reddy, Roger L. Sheley, Lincoln Smith, Melissa C. Smith, Keirith A. Snyder, Matthew A. Tancos, Natalie M. West, Gregory S. Wheeler, Martin M. Williams, Julie Wolf, Carissa L. Wonkka, Alice A. Wright, Jing Xi, Lew H. Ziska
-
- Journal:
- Weed Science / Volume 71 / Issue 4 / July 2023
- Published online by Cambridge University Press:
- 16 August 2023, pp. 312-327
-
- Article
-
- You have access Access
- Open access
- HTML
- Export citation
-
The U.S. Department of Agriculture–Agricultural Research Service (USDA-ARS) has been a leader in weed science research covering topics ranging from the development and use of integrated weed management (IWM) tactics to basic mechanistic studies, including biotic resistance of desirable plant communities and herbicide resistance. ARS weed scientists have worked in agricultural and natural ecosystems, including agronomic and horticultural crops, pastures, forests, wild lands, aquatic habitats, wetlands, and riparian areas. Through strong partnerships with academia, state agencies, private industry, and numerous federal programs, ARS weed scientists have made contributions to discoveries in the newest fields of robotics and genetics, as well as the traditional and fundamental subjects of weed–crop competition and physiology and integration of weed control tactics and practices. Weed science at ARS is often overshadowed by other research topics; thus, few are aware of the long history of ARS weed science and its important contributions. This review is the result of a symposium held at the Weed Science Society of America’s 62nd Annual Meeting in 2022 that included 10 separate presentations in a virtual Weed Science Webinar Series. The overarching themes of management tactics (IWM, biological control, and automation), basic mechanisms (competition, invasive plant genetics, and herbicide resistance), and ecosystem impacts (invasive plant spread, climate change, conservation, and restoration) represent core ARS weed science research that is dynamic and efficacious and has been a significant component of the agency’s national and international efforts. This review highlights current studies and future directions that exemplify the science and collaborative relationships both within and outside ARS. Given the constraints of weeds and invasive plants on all aspects of food, feed, and fiber systems, there is an acknowledged need to face new challenges, including agriculture and natural resources sustainability, economic resilience and reliability, and societal health and well-being.
Pro-inflammatory markers predict response to sequential pharmacotherapy in major depressive disorder: a CAN-BIND-1 report
- M. I. Husain, J. A. Foster, B. L. Mason, S. Chen, W. Wang, S. Rotzinger, S. Rizvi, K. Ho, R. Lam, G. MacQueen, R. Milev, B. N. Frey, D. Mueller, G. Turecki, M. Jha, M. Trivedi, S. H. Kennedy
-
- Journal:
- European Psychiatry / Volume 66 / Issue S1 / March 2023
- Published online by Cambridge University Press:
- 19 July 2023, p. S295
-
- Article
-
- You have access Access
- Open access
- Export citation
-
Introduction
Despite replicated cross-sectional evidence of aberrant levels of peripheral inflammatory markers in individuals with major depressive disorder (MDD), there is limited literature on associations between inflammatory tone and response to sequential pharmacotherapies.
ObjectivesTo assess associations between plasma levels of pro-inflammatory markers and treatment response to escitalopram and adjunctive aripiprazole in adults with MDD.
MethodsIn a 16-week open-label clinical trial, 211 participants with MDD were treated with escitalopram 10– 20 mg daily for 8 weeks. Responders continued on escitalopram while non-responders received adjunctive aripiprazole 2–10 mg daily for 8 weeks. Plasma levels of pro-inflammatory markers – C-reactive protein, Interleukin (IL)-1β, IL-6, IL-17, Interferon gamma (IFN)-Γ, Tumour Necrosis Factor (TNF)-α, and Chemokine C–C motif ligand-2 (CCL-2) - measured at baseline, and after 2, 8 and 16 weeks were included in logistic regression analyses to assess associations between inflammatory markers and treatment response.
ResultsPre-treatment levels of IFN-Γ and CCL-2 were significantly higher in escitalopram non-responders compared to responders. Pre-treatment IFN-Γ and CCL-2 levels were significantly associated with a lower of odds of response to escitalopram at 8 weeks. Increases in CCL-2 levels from weeks 8 to 16 in escitalopram non-responders were significantly associated with higher odds of non-response to adjunctive aripiprazole at week 16.
ConclusionsPre-treatment levels of IFN-Γ and CCL-2 were predictive of response to escitalopram. Increasing levels of these pro-inflammatory markers may predict non-response to adjunctive aripiprazole. These findings require validation in independent clinical populations.
Disclosure of InterestNone Declared
Predictors of olfactory improvement after endoscopic sinus surgery in chronic rhinosinusitis with nasal polyps
- A K Hernandez, O Wendler, S Mayr, H Iro, T Hummel, S K Mueller
-
- Journal:
- The Journal of Laryngology & Otology / Volume 137 / Issue 5 / May 2023
- Published online by Cambridge University Press:
- 06 July 2022, pp. 524-531
- Print publication:
- May 2023
-
- Article
-
- You have access Access
- Open access
- HTML
- Export citation
-
Objective
This study aimed to determine the predictors of olfactory improvement after endoscopic sinus surgery among patients with chronic rhinosinusitis with nasal polyps.
MethodThis prospective cohort study included patients admitted to a university hospital between 2006 and 2012. Assessment using odour identification testing, a sinonasal symptom questionnaire, the Rhinosinusitis Disability Index and mucus biomarker levels was performed at various time points. Correlation of variables with identification score differences at six post-operative time points and at baseline was performed, followed by multiple linear regression to determine significant predictors at each of the six post-operative time points.
ResultsBaseline absence of acute sinusitis, elevated serpin F2 and anterior rhinorrhoea predict early olfactory improvement, whereas baseline allergic rhinitis predicts late olfactory improvement. Baseline odour identification score was the strongest predictor across all time points.
ConclusionPatients with chronic rhinosinusitis and nasal polyps with worse disease or baseline olfactory function may benefit more from endoscopic sinus surgery in terms of olfactory improvement.
Neutron Star Extreme Matter Observatory: A kilohertz-band gravitational-wave detector in the global network
- Part of
- K. Ackley, V. B. Adya, P. Agrawal, P. Altin, G. Ashton, M. Bailes, E. Baltinas, A. Barbuio, D. Beniwal, C. Blair, D. Blair, G. N. Bolingbroke, V. Bossilkov, S. Shachar Boublil, D. D. Brown, B. J. Burridge, J. Calderon Bustillo, J. Cameron, H. Tuong Cao, J. B. Carlin, S. Chang, P. Charlton, C. Chatterjee, D. Chattopadhyay, X. Chen, J. Chi, J. Chow, Q. Chu, A. Ciobanu, T. Clarke, P. Clearwater, J. Cooke, D. Coward, H. Crisp, R. J. Dattatri, A. T. Deller, D. A. Dobie, L. Dunn, P. J. Easter, J. Eichholz, R. Evans, C. Flynn, G. Foran, P. Forsyth, Y. Gai, S. Galaudage, D. K. Galloway, B. Gendre, B. Goncharov, S. Goode, D. Gozzard, B. Grace, A. W. Graham, A. Heger, F. Hernandez Vivanco, R. Hirai, N. A. Holland, Z. J. Holmes, E. Howard, E. Howell, G. Howitt, M. T. Hübner, J. Hurley, C. Ingram, V. Jaberian Hamedan, K. Jenner, L. Ju, D. P. Kapasi, T. Kaur, N. Kijbunchoo, M. Kovalam, R. Kumar Choudhary, P. D. Lasky, M. Y. M. Lau, J. Leung, J. Liu, K. Loh, A. Mailvagan, I. Mandel, J. J. McCann, D. E. McClelland, K. McKenzie, D. McManus, T. McRae, A. Melatos, P. Meyers, H. Middleton, M. T. Miles, M. Millhouse, Y. Lun Mong, B. Mueller, J. Munch, J. Musiov, S. Muusse, R. S. Nathan, Y. Naveh, C. Neijssel, B. Neil, S. W. S. Ng, V. Oloworaran, D. J. Ottaway, M. Page, J. Pan, M. Pathak, E. Payne, J. Powell, J. Pritchard, E. Puckridge, A. Raidani, V. Rallabhandi, D. Reardon, J. A. Riley, L. Roberts, I. M. Romero-Shaw, T. J. Roocke, G. Rowell, N. Sahu, N. Sarin, L. Sarre, H. Sattari, M. Schiworski, S. M. Scott, R. Sengar, D. Shaddock, R. Shannon, J. SHI, P. Sibley, B. J. J. Slagmolen, T. Slaven-Blair, R. J. E. Smith, J. Spollard, L. Steed, L. Strang, H. Sun, A. Sunderland, S. Suvorova, C. Talbot, E. Thrane, D. Töyrä, P. Trahanas, A. Vajpeyi, J. V. van Heijningen, A. F. Vargas, P. J. Veitch, A. Vigna-Gomez, A. Wade, K. Walker, Z. Wang, R. L. Ward, K. Ward, S. Webb, L. Wen, K. Wette, R. Wilcox, J. Winterflood, C. Wolf, B. Wu, M. Jet Yap, Z. You, H. Yu, J. Zhang, J. Zhang, C. Zhao, X. Zhu
-
- Journal:
- Publications of the Astronomical Society of Australia / Volume 37 / 2020
- Published online by Cambridge University Press:
- 05 November 2020, e047
-
- Article
-
- You have access Access
- HTML
- Export citation
-
Gravitational waves from coalescing neutron stars encode information about nuclear matter at extreme densities, inaccessible by laboratory experiments. The late inspiral is influenced by the presence of tides, which depend on the neutron star equation of state. Neutron star mergers are expected to often produce rapidly rotating remnant neutron stars that emit gravitational waves. These will provide clues to the extremely hot post-merger environment. This signature of nuclear matter in gravitational waves contains most information in the 2–4 kHz frequency band, which is outside of the most sensitive band of current detectors. We present the design concept and science case for a Neutron Star Extreme Matter Observatory (NEMO): a gravitational-wave interferometer optimised to study nuclear physics with merging neutron stars. The concept uses high-circulating laser power, quantum squeezing, and a detector topology specifically designed to achieve the high-frequency sensitivity necessary to probe nuclear matter using gravitational waves. Above 1 kHz, the proposed strain sensitivity is comparable to full third-generation detectors at a fraction of the cost. Such sensitivity changes expected event rates for detection of post-merger remnants from approximately one per few decades with two A+ detectors to a few per year and potentially allow for the first gravitational-wave observations of supernovae, isolated neutron stars, and other exotica.
FROM BAUHAUS TO DESIGN THINKING AND BEYOND: A COMPARISON OF TWO DESIGN EDUCATIONAL SCHOOLS
- Part of
- K. Thoring, R. M. Mueller, S. Giegler, P. Badke-Schaub
-
- Journal:
- Proceedings of the Design Society: DESIGN Conference / Volume 1 / May 2020
- Published online by Cambridge University Press:
- 11 June 2020, pp. 1815-1824
-
- Article
-
- You have access Access
- Open access
- Export citation
-
This paper compares two pioneering design educational approaches: the historic Bauhaus school founded in 1919 in Germany, and contemporary design thinking education, based on the example of the “HPI School of Design Thinking”. We compare both approaches according to six emerging categories: (1) curriculum, (2) multi-disciplinarity, (3) mind-set and culture, (4) study environment, (5) conditions for innovation, and (6) socio-economic context. We outline differences and similarities and discuss the possible impact for future design education.
P0104 - Improvement of neuronal energy metabolism and stabilization of mitchondrial function by ginkgo biloba Extract
- A. Eckert, S. Hauptmann, U. Lipka, R. Abdel-Kader, I. Scherping, K. Leuner, W.E. Mueller
-
- Journal:
- European Psychiatry / Volume 23 / Issue S2 / April 2008
- Published online by Cambridge University Press:
- 16 April 2020, p. S223
-
- Article
-
- You have access Access
- Export citation
-
Background:
Ginkgo biloba extract (EGb761) has been used for many years to treat age-related cognitive disorders. Recent studies also indicate a therapeutic potential of EGb761 in Alzheimer disease (AD). Bolstered evidence indicates that mitochondrial abnormalities might be part of the spectrum of chronic oxidative stress occurring in aging and AD finally contributing to synaptic failure and neuronal degeneration.
Objective:We investigated the protective effects of EGb761 on mitochondrial function and ATP production.
Methods:As cellular models, PC12 cells and acutely dissociated brain cells from young and aged mice were investigated under a variety of conditions, e.g. oxidative and nitrosative stress, associated with impaired mitochondrial function and decreased membrane potential.
Results:EGb761 alleviated mitochondrial functions in vitro at concentrations as low as 0.01mg/ml. The effect of EGb761 was specific, since protective effects were mainly seen after specifically impairing respiratory chain complexes II, IV, and V. Comparable findings were made with dissociated brain cells from young and aged mice where usually aged brain cells were more sensitive for the protective effects of EGb761. In addition, PC12 cells bearing an AD-related mutation in the amyloid precursor protein, that leads to enhanced beta-amyloid production, showed a greater benefit from treatment with EGb761 than control cells.
Conclusions:Taking together, our finding clearly show stabilization and protection of mitochondrial function as a specific and very sensitive property of EGb761 at rather low concentrations. This mechanism can explain many of the until now rather unrelated observations of EGb761 in brain aging and neurodegeneration.
A Comparison of Symmetrical and Asymmetrical Triazine Herbicides for Enhanced Degradation in Three Midwestern Soils
- Ethan T. Parker, Micheal D. K. Owen, Mark L. Bernards, William S. Curran, Lawrence E. Steckel, Thomas C. Mueller
-
- Journal:
- Weed Science / Volume 66 / Issue 5 / September 2018
- Published online by Cambridge University Press:
- 11 September 2018, pp. 673-679
-
- Article
- Export citation
-
The triazines are one of the most widely used herbicide classes ever developed and are critical for managing weed populations that have developed herbicide resistance. These herbicides are traditionally valued for their residual weed control in more than 50 crops. Scientific literature suggests that atrazine, and perhaps other s-triazines, may no longer remain persistent in soils due to enhanced microbial degradation. Experiments examined the rate of degradation of atrazine and two other triazine herbicides, simazine and metribuzin, in both atrazine-adapted and non-history Corn Belt soils, with similar soils being used from each state as a comparison of potential triazine degradation. In three soils with no history of atrazine use, the t1/2 of atrazine was at least four times greater than in three soils with a history of atrazine use. Simazine degradation in the same three sets of soils was 2.4 to 15 times more rapid in history soils than non-history soils. Metribuzin in history soils degraded at 0.6, 0.9, and 1.9 times the rate seen in the same three non-history soils. These results indicate enhanced degradation of the symmetrical triazine simazine, but not of the asymmetrical triazine metribuzin.
Resting-state thalamic dysconnectivity in schizophrenia and relationships with symptoms
- J. Ferri, J. M. Ford, B. J. Roach, J. A. Turner, T. G. van Erp, J. Voyvodic, A. Preda, A. Belger, J. Bustillo, D. O'Leary, B. A. Mueller, K. O. Lim, S. C. McEwen, V. D. Calhoun, M. Diaz, G. Glover, D. Greve, C. G. Wible, J. G. Vaidya, S. G. Potkin, D. H. Mathalon
-
- Journal:
- Psychological Medicine / Volume 48 / Issue 15 / November 2018
- Published online by Cambridge University Press:
- 15 February 2018, pp. 2492-2499
-
- Article
- Export citation
-
Background
Schizophrenia (SZ) is a severe neuropsychiatric disorder associated with disrupted connectivity within the thalamic-cortico-cerebellar network. Resting-state functional connectivity studies have reported thalamic hypoconnectivity with the cerebellum and prefrontal cortex as well as thalamic hyperconnectivity with sensory cortical regions in SZ patients compared with healthy comparison participants (HCs). However, fundamental questions remain regarding the clinical significance of these connectivity abnormalities.
MethodResting state seed-based functional connectivity was used to investigate thalamus to whole brain connectivity using multi-site data including 183 SZ patients and 178 matched HCs. Statistical significance was based on a voxel-level FWE-corrected height threshold of p < 0.001. The relationships between positive and negative symptoms of SZ and regions of the brain demonstrating group differences in thalamic connectivity were examined.
ResultsHC and SZ participants both demonstrated widespread positive connectivity between the thalamus and cortical regions. Compared with HCs, SZ patients had reduced thalamic connectivity with bilateral cerebellum and anterior cingulate cortex. In contrast, SZ patients had greater thalamic connectivity with multiple sensory-motor regions, including bilateral pre- and post-central gyrus, middle/inferior occipital gyrus, and middle/superior temporal gyrus. Thalamus to middle temporal gyrus connectivity was positively correlated with hallucinations and delusions, while thalamus to cerebellar connectivity was negatively correlated with delusions and bizarre behavior.
ConclusionsThalamic hyperconnectivity with sensory regions and hypoconnectivity with cerebellar regions in combination with their relationship to clinical features of SZ suggest that thalamic dysconnectivity may be a core neurobiological feature of SZ that underpins positive symptoms.
Salmonella Typhimurium in livestock in Great Britain – trends observed over a 32-year period
- D. Mueller-Doblies, K. C. R. Speed, S. Kidd, R. H. Davies
-
- Journal:
- Epidemiology & Infection / Volume 146 / Issue 4 / March 2018
- Published online by Cambridge University Press:
- 08 February 2018, pp. 409-422
-
- Article
-
- You have access Access
- HTML
- Export citation
-
In this retrospective study, we describe and analyse Salmonella data from four livestock species in Great Britain between 1983 and 2014, focusing on Salmonella Typhimurium. A total of 96 044 Salmonella isolates were obtained during the study period. S. Typhimurium was the predominant serovar isolated from cattle and pigs and represented 40.7% (18 455/45 336) and 58.3% (4495/7709) of isolates from these species respectively, while it only accounted for 6.7% (2114/31 492) of chicken isolates and 8.1% (926/11 507) of turkey isolates. Over the study period, DT104 was the most common phage type in all four species; however, DT104 peaked in occurrence between 1995 and 1999, but is currently rare.
Monophasic strains of S. Typhimurium represented less than 3% of all Salmonella isolates in cattle and chickens in 2014, but accounted for 10.4% of all turkey isolates and 39.0% of all pig isolates in the same year.
Salmonella isolates were tested for their in vitro susceptibility to 16 antimicrobials. Antimicrobial resistance of S. Typhimurium isolates is largely influenced by the dominance of specific phage types at a certain time, which are commonly associated with particular resistance patterns. Changes in resistance patterns over time were analysed and compared between species.
Efficacy and Safening of Aryloxyphenoxypropionate Herbicides when Tank-Mixed with Triclopyr for Bermudagrass Control in Zoysiagrass Turf
- D. F. Lewis, J. S. Mcelroy, J. C. Sorochan, T. C. Mueller, T. J. Samples, G. K. Breeden
-
- Journal:
- Weed Technology / Volume 24 / Issue 4 / December 2010
- Published online by Cambridge University Press:
- 20 January 2017, pp. 489-494
-
- Article
- Export citation
-
Aryloxyphenoxypropionate (AOPP) herbicides are used to control bermudagrass contamination in various turfgrasses. Applying AOPP herbicides alone can cause unacceptable injury to zoysiagrass but injury can be reduced when tank-mixed with triclopyr. There are limited data illustrating the extent of bermudagrass control and zoysiagrass cultivar tolerance when these compounds are combined. Research was conducted to determine the efficacy of multiple AOPP herbicides applied alone and tank-mixed with triclopyr for bermudagrass control in zoysiagrass turf. Treatments include three sequential applications of cyhalofop (0.32 kg ai ha−1), fenoxaprop (0.14 kg ha−1), fluazifop (0.11 kg ha−1), or quizalofop (0.09 kg ha−1) applied alone and tank-mixed with triclopyr (1.12 kg ae ha−1) applied to ‘Tifway’ bermudagrass, and ‘Diamond’, ‘Palisades’, and ‘Zenith’ zoysiagrass. Tifway bermudagrass control ranged from 41 to 69% and digital image analysis turf coverage data ranged from 18 to 50% for AOPP herbicides applied alone. The addition of triclopyr to AOPP herbicides increased bermudagrass control (64–79%) and reduced turf coverage (8–29%). Palisades and Zenith zoysiagrass exhibited less injury (1–18%) and greater turf coverage (84–86%) when AOPP herbicides were tank-mixed with triclopyr compared to AOPP herbicides applied alone. Diamond zoysiagrass was not tolerant to any AOPP herbicides applied alone or tank-mixed with triclopyr, except for fluazifop alone (18% injury and 93% turf coverage). Visual ratings and digital image analysis turf coverage data had a strong negative correlation over all tested turfgrasses. In general, AOPP herbicides plus triclopyr will control bermudagrass greater and injure zoysiagrass less compared to AOPP herbicides applied alone; however, these mixtures can cause unacceptable injury to Diamond zoysiagrass.
Evaluation of chest radiography, lytA real-time PCR, and other routine tests for diagnosis of community-acquired pneumonia and estimation of possible attributable fraction of pneumococcus in northern Togo
- A. BLAKE, B. M. NJANPOP-LAFOURCADE, J. N. TELLES, A. RAJOHARISON, M. S. MAKAWA, K. AGBENOKO, S. TAMEKLOE, J. E. MUELLER, H. TALL, B. D. GESSNER, G. PARANHOS-BACCALÀ, J. C. MOÏSI
-
- Journal:
- Epidemiology & Infection / Volume 145 / Issue 3 / February 2017
- Published online by Cambridge University Press:
- 17 November 2016, pp. 583-594
-
- Article
-
- You have access Access
- Open access
- HTML
- Export citation
-
Streptococcus pneumoniae (Spn) is a leading cause of community-acquired pneumonia (CAP), yet existing diagnostic tools remain inadequate. We aimed to evaluate laboratory and radiological methods for detecting pneumococcal aetiology in CAP patients and to estimate Spn prevalence in this group. All-aged patients hospitalized with clinically defined CAP in northern Togo were enrolled during 2010–2013. Latent class analysis pooled results of semi-automated blood culture (SABC), whole blood lytA real-time polymerase chain reaction (rt-PCR), serum C-reactive protein (CRP), and chest radiography (CXR) and categorized patients as likely pneumococcal or non-pneumococcal CAP. We enrolled 1684 patients; 1501 had results for all tests. CXR, SABC, lytA rt-PCR and CRP >71·2 mg/l had sensitivities of 94% [95% confidence interval (CI) 87–100], 13% (95% CI 10–16), 17% (95% CI 14–21) and 78% (95% CI 75–80), and specificities of 88% (95% CI 84–93), 100% (95% CI 99–100), 97% (95% CI 96–99) and 77% (95% CI 75–79), respectively. Pneumococcal attributable proportion was 34% (95% CI 32–37), increasing with age and in men. We estimated that Spn caused one third of CAP. Whole blood lytA rt-PCR was more sensitive than SABC; both had low sensitivity and high specificity. Conversely CXR was highly sensitive and reasonably specific; it could be a useful tool for epidemiological studies aiming to define Spn pneumonia incidence across all ages.
Current Status of the Quality of 4H-SiC Substrates and Epilayers for Power Device Applications
- M. Dudley, H. Wang, Jianqiu Guo, Yu Yang, Balaji Raghothamachar, J. Zhang, B. Thomas, G. Chung, E. K. Sanchez, D. Hansen, S. G. Mueller
-
- Journal:
- MRS Advances / Volume 1 / Issue 2 / 2016
- Published online by Cambridge University Press:
- 26 January 2016, pp. 91-102
- Print publication:
- 2016
-
- Article
- Export citation
-
Interfacial dislocations (IDs) and half-loop arrays (HLAs) present in the epilayers of 4H-SiC crystal are known to have a deleterious effect on device performance. Synchrotron X-ray Topography studies carried out on n-type 4H-SiC offcut wafers before and after epitaxial growth show that in many cases BPD segments in the substrate are responsible for creating IDs and HLAs during CVD growth. This paper reviews the behaviors of BPDs in the substrate during the epitaxial growth in different cases: (1) screw-oriented BPD segments intersecting the surface replicate directly through the interface during the epitaxial growth and take part in stress relaxation process by creating IDs and HLAs (Matthews-Blakeslee model [1] ); (2) non-screw oriented BPD half loop intersecting the surface glides towards and replicates through the interface, while the intersection points convert to threading edge dislocations (TEDs) and pin the half loop, leaving straight screw segments in the epilayer and then create IDs and HLAs; (3) edge oriented short BPD segments well below the surface get dragged towards the interface during epitaxial growth, leaving two long screw segments in their wake, some of which replicate through the interface and create IDs and HLAs. The driving force for the BPDs to glide toward the interface is thermal stress and driving force for the relaxation process to occur is the lattice parameter difference at growth temperature which results from the doping concentration difference between the substrate and epilayer.
New Hybrid Peak-Force Tapping/Near-Field Microscope for Nano-Chemical and Nano-Mechanical Imaging of Graphene Plasmons, Polymers and Proteins
- M. Wagner, G. Andreev, K. Carneiro, S. Habelitz, T. Mueller
-
- Journal:
- Microscopy and Microanalysis / Volume 21 / Issue S3 / August 2015
- Published online by Cambridge University Press:
- 23 September 2015, pp. 1873-1874
- Print publication:
- August 2015
-
- Article
-
- You have access Access
- Export citation
Contributors
-
- By Mitchell Aboulafia, Frederick Adams, Marilyn McCord Adams, Robert M. Adams, Laird Addis, James W. Allard, David Allison, William P. Alston, Karl Ameriks, C. Anthony Anderson, David Leech Anderson, Lanier Anderson, Roger Ariew, David Armstrong, Denis G. Arnold, E. J. Ashworth, Margaret Atherton, Robin Attfield, Bruce Aune, Edward Wilson Averill, Jody Azzouni, Kent Bach, Andrew Bailey, Lynne Rudder Baker, Thomas R. Baldwin, Jon Barwise, George Bealer, William Bechtel, Lawrence C. Becker, Mark A. Bedau, Ernst Behler, José A. Benardete, Ermanno Bencivenga, Jan Berg, Michael Bergmann, Robert L. Bernasconi, Sven Bernecker, Bernard Berofsky, Rod Bertolet, Charles J. Beyer, Christian Beyer, Joseph Bien, Joseph Bien, Peg Birmingham, Ivan Boh, James Bohman, Daniel Bonevac, Laurence BonJour, William J. Bouwsma, Raymond D. Bradley, Myles Brand, Richard B. Brandt, Michael E. Bratman, Stephen E. Braude, Daniel Breazeale, Angela Breitenbach, Jason Bridges, David O. Brink, Gordon G. Brittan, Justin Broackes, Dan W. Brock, Aaron Bronfman, Jeffrey E. Brower, Bartosz Brozek, Anthony Brueckner, Jeffrey Bub, Lara Buchak, Otavio Bueno, Ann E. Bumpus, Robert W. Burch, John Burgess, Arthur W. Burks, Panayot Butchvarov, Robert E. Butts, Marina Bykova, Patrick Byrne, David Carr, Noël Carroll, Edward S. Casey, Victor Caston, Victor Caston, Albert Casullo, Robert L. Causey, Alan K. L. Chan, Ruth Chang, Deen K. Chatterjee, Andrew Chignell, Roderick M. Chisholm, Kelly J. Clark, E. J. Coffman, Robin Collins, Brian P. Copenhaver, John Corcoran, John Cottingham, Roger Crisp, Frederick J. Crosson, Antonio S. Cua, Phillip D. Cummins, Martin Curd, Adam Cureton, Andrew Cutrofello, Stephen Darwall, Paul Sheldon Davies, Wayne A. Davis, Timothy Joseph Day, Claudio de Almeida, Mario De Caro, Mario De Caro, John Deigh, C. F. Delaney, Daniel C. Dennett, Michael R. DePaul, Michael Detlefsen, Daniel Trent Devereux, Philip E. Devine, John M. Dillon, Martin C. Dillon, Robert DiSalle, Mary Domski, Alan Donagan, Paul Draper, Fred Dretske, Mircea Dumitru, Wilhelm Dupré, Gerald Dworkin, John Earman, Ellery Eells, Catherine Z. Elgin, Berent Enç, Ronald P. Endicott, Edward Erwin, John Etchemendy, C. Stephen Evans, Susan L. Feagin, Solomon Feferman, Richard Feldman, Arthur Fine, Maurice A. Finocchiaro, William FitzPatrick, Richard E. Flathman, Gvozden Flego, Richard Foley, Graeme Forbes, Rainer Forst, Malcolm R. Forster, Daniel Fouke, Patrick Francken, Samuel Freeman, Elizabeth Fricker, Miranda Fricker, Michael Friedman, Michael Fuerstein, Richard A. Fumerton, Alan Gabbey, Pieranna Garavaso, Daniel Garber, Jorge L. A. Garcia, Robert K. Garcia, Don Garrett, Philip Gasper, Gerald Gaus, Berys Gaut, Bernard Gert, Roger F. Gibson, Cody Gilmore, Carl Ginet, Alan H. Goldman, Alvin I. Goldman, Alfonso Gömez-Lobo, Lenn E. Goodman, Robert M. Gordon, Stefan Gosepath, Jorge J. E. Gracia, Daniel W. Graham, George A. Graham, Peter J. Graham, Richard E. Grandy, I. Grattan-Guinness, John Greco, Philip T. Grier, Nicholas Griffin, Nicholas Griffin, David A. Griffiths, Paul J. Griffiths, Stephen R. Grimm, Charles L. Griswold, Charles B. Guignon, Pete A. Y. Gunter, Dimitri Gutas, Gary Gutting, Paul Guyer, Kwame Gyekye, Oscar A. Haac, Raul Hakli, Raul Hakli, Michael Hallett, Edward C. Halper, Jean Hampton, R. James Hankinson, K. R. Hanley, Russell Hardin, Robert M. Harnish, William Harper, David Harrah, Kevin Hart, Ali Hasan, William Hasker, John Haugeland, Roger Hausheer, William Heald, Peter Heath, Richard Heck, John F. Heil, Vincent F. Hendricks, Stephen Hetherington, Francis Heylighen, Kathleen Marie Higgins, Risto Hilpinen, Harold T. Hodes, Joshua Hoffman, Alan Holland, Robert L. Holmes, Richard Holton, Brad W. Hooker, Terence E. Horgan, Tamara Horowitz, Paul Horwich, Vittorio Hösle, Paul Hoβfeld, Daniel Howard-Snyder, Frances Howard-Snyder, Anne Hudson, Deal W. Hudson, Carl A. Huffman, David L. Hull, Patricia Huntington, Thomas Hurka, Paul Hurley, Rosalind Hursthouse, Guillermo Hurtado, Ronald E. Hustwit, Sarah Hutton, Jonathan Jenkins Ichikawa, Harry A. Ide, David Ingram, Philip J. Ivanhoe, Alfred L. Ivry, Frank Jackson, Dale Jacquette, Joseph Jedwab, Richard Jeffrey, David Alan Johnson, Edward Johnson, Mark D. Jordan, Richard Joyce, Hwa Yol Jung, Robert Hillary Kane, Tomis Kapitan, Jacquelyn Ann K. Kegley, James A. Keller, Ralph Kennedy, Sergei Khoruzhii, Jaegwon Kim, Yersu Kim, Nathan L. King, Patricia Kitcher, Peter D. Klein, E. D. Klemke, Virginia Klenk, George L. Kline, Christian Klotz, Simo Knuuttila, Joseph J. Kockelmans, Konstantin Kolenda, Sebastian Tomasz Kołodziejczyk, Isaac Kramnick, Richard Kraut, Fred Kroon, Manfred Kuehn, Steven T. Kuhn, Henry E. Kyburg, John Lachs, Jennifer Lackey, Stephen E. Lahey, Andrea Lavazza, Thomas H. Leahey, Joo Heung Lee, Keith Lehrer, Dorothy Leland, Noah M. Lemos, Ernest LePore, Sarah-Jane Leslie, Isaac Levi, Andrew Levine, Alan E. Lewis, Daniel E. Little, Shu-hsien Liu, Shu-hsien Liu, Alan K. L. Chan, Brian Loar, Lawrence B. Lombard, John Longeway, Dominic McIver Lopes, Michael J. Loux, E. J. Lowe, Steven Luper, Eugene C. Luschei, William G. Lycan, David Lyons, David Macarthur, Danielle Macbeth, Scott MacDonald, Jacob L. Mackey, Louis H. Mackey, Penelope Mackie, Edward H. Madden, Penelope Maddy, G. B. Madison, Bernd Magnus, Pekka Mäkelä, Rudolf A. Makkreel, David Manley, William E. Mann (W.E.M.), Vladimir Marchenkov, Peter Markie, Jean-Pierre Marquis, Ausonio Marras, Mike W. Martin, A. P. Martinich, William L. McBride, David McCabe, Storrs McCall, Hugh J. McCann, Robert N. McCauley, John J. McDermott, Sarah McGrath, Ralph McInerny, Daniel J. McKaughan, Thomas McKay, Michael McKinsey, Brian P. McLaughlin, Ernan McMullin, Anthonie Meijers, Jack W. Meiland, William Jason Melanson, Alfred R. Mele, Joseph R. Mendola, Christopher Menzel, Michael J. Meyer, Christian B. Miller, David W. Miller, Peter Millican, Robert N. Minor, Phillip Mitsis, James A. Montmarquet, Michael S. Moore, Tim Moore, Benjamin Morison, Donald R. Morrison, Stephen J. Morse, Paul K. Moser, Alexander P. D. Mourelatos, Ian Mueller, James Bernard Murphy, Mark C. Murphy, Steven Nadler, Jan Narveson, Alan Nelson, Jerome Neu, Samuel Newlands, Kai Nielsen, Ilkka Niiniluoto, Carlos G. Noreña, Calvin G. Normore, David Fate Norton, Nikolaj Nottelmann, Donald Nute, David S. Oderberg, Steve Odin, Michael O’Rourke, Willard G. Oxtoby, Heinz Paetzold, George S. Pappas, Anthony J. Parel, Lydia Patton, R. P. Peerenboom, Francis Jeffry Pelletier, Adriaan T. Peperzak, Derk Pereboom, Jaroslav Peregrin, Glen Pettigrove, Philip Pettit, Edmund L. Pincoffs, Andrew Pinsent, Robert B. Pippin, Alvin Plantinga, Louis P. Pojman, Richard H. Popkin, John F. Post, Carl J. Posy, William J. Prior, Richard Purtill, Michael Quante, Philip L. Quinn, Philip L. Quinn, Elizabeth S. Radcliffe, Diana Raffman, Gerard Raulet, Stephen L. Read, Andrews Reath, Andrew Reisner, Nicholas Rescher, Henry S. Richardson, Robert C. Richardson, Thomas Ricketts, Wayne D. Riggs, Mark Roberts, Robert C. Roberts, Luke Robinson, Alexander Rosenberg, Gary Rosenkranz, Bernice Glatzer Rosenthal, Adina L. Roskies, William L. Rowe, T. M. Rudavsky, Michael Ruse, Bruce Russell, Lilly-Marlene Russow, Dan Ryder, R. M. Sainsbury, Joseph Salerno, Nathan Salmon, Wesley C. Salmon, Constantine Sandis, David H. Sanford, Marco Santambrogio, David Sapire, Ruth A. Saunders, Geoffrey Sayre-McCord, Charles Sayward, James P. Scanlan, Richard Schacht, Tamar Schapiro, Frederick F. Schmitt, Jerome B. Schneewind, Calvin O. Schrag, Alan D. Schrift, George F. Schumm, Jean-Loup Seban, David N. Sedley, Kenneth Seeskin, Krister Segerberg, Charlene Haddock Seigfried, Dennis M. Senchuk, James F. Sennett, William Lad Sessions, Stewart Shapiro, Tommie Shelby, Donald W. Sherburne, Christopher Shields, Roger A. Shiner, Sydney Shoemaker, Robert K. Shope, Kwong-loi Shun, Wilfried Sieg, A. John Simmons, Robert L. Simon, Marcus G. Singer, Georgette Sinkler, Walter Sinnott-Armstrong, Matti T. Sintonen, Lawrence Sklar, Brian Skyrms, Robert C. Sleigh, Michael Anthony Slote, Hans Sluga, Barry Smith, Michael Smith, Robin Smith, Robert Sokolowski, Robert C. Solomon, Marta Soniewicka, Philip Soper, Ernest Sosa, Nicholas Southwood, Paul Vincent Spade, T. L. S. Sprigge, Eric O. Springsted, George J. Stack, Rebecca Stangl, Jason Stanley, Florian Steinberger, Sören Stenlund, Christopher Stephens, James P. Sterba, Josef Stern, Matthias Steup, M. A. Stewart, Leopold Stubenberg, Edith Dudley Sulla, Frederick Suppe, Jere Paul Surber, David George Sussman, Sigrún Svavarsdóttir, Zeno G. Swijtink, Richard Swinburne, Charles C. Taliaferro, Robert B. Talisse, John Tasioulas, Paul Teller, Larry S. Temkin, Mark Textor, H. S. Thayer, Peter Thielke, Alan Thomas, Amie L. Thomasson, Katherine Thomson-Jones, Joshua C. Thurow, Vzalerie Tiberius, Terrence N. Tice, Paul Tidman, Mark C. Timmons, William Tolhurst, James E. Tomberlin, Rosemarie Tong, Lawrence Torcello, Kelly Trogdon, J. D. Trout, Robert E. Tully, Raimo Tuomela, John Turri, Martin M. Tweedale, Thomas Uebel, Jennifer Uleman, James Van Cleve, Harry van der Linden, Peter van Inwagen, Bryan W. Van Norden, René van Woudenberg, Donald Phillip Verene, Samantha Vice, Thomas Vinci, Donald Wayne Viney, Barbara Von Eckardt, Peter B. M. Vranas, Steven J. Wagner, William J. Wainwright, Paul E. Walker, Robert E. Wall, Craig Walton, Douglas Walton, Eric Watkins, Richard A. Watson, Michael V. Wedin, Rudolph H. Weingartner, Paul Weirich, Paul J. Weithman, Carl Wellman, Howard Wettstein, Samuel C. Wheeler, Stephen A. White, Jennifer Whiting, Edward R. Wierenga, Michael Williams, Fred Wilson, W. Kent Wilson, Kenneth P. Winkler, John F. Wippel, Jan Woleński, Allan B. Wolter, Nicholas P. Wolterstorff, Rega Wood, W. Jay Wood, Paul Woodruff, Alison Wylie, Gideon Yaffe, Takashi Yagisawa, Yutaka Yamamoto, Keith E. Yandell, Xiaomei Yang, Dean Zimmerman, Günter Zoller, Catherine Zuckert, Michael Zuckert, Jack A. Zupko (J.A.Z.)
- Edited by Robert Audi, University of Notre Dame, Indiana
-
- Book:
- The Cambridge Dictionary of Philosophy
- Published online:
- 05 August 2015
- Print publication:
- 27 April 2015, pp ix-xxx
-
- Chapter
- Export citation
X-ray Topography Studies of Relaxation during the Homo-Epitaxy of 4H-SiC
- H. Wang, M. Dudley, J. Zhang, B. Thomas, G. Chung, E. K. Sanchez, D. Hansen, S. G. Mueller
-
- Journal:
- MRS Online Proceedings Library Archive / Volume 1741 / 2015
- Published online by Cambridge University Press:
- 06 February 2015, mrsf14-1741-aa13-02
- Print publication:
- 2015
-
- Article
- Export citation
-
A review is presented of Synchrotron X-ray Topography and KOH etching studies carried out on n type 4H-SiC offcut substrates before and after homo-epitaxial growth to study defect replication and strain relaxation processes and identify the nucleation sources of both interfacial dislocations (IDs) and half-loop arrays (HLAs) which are known to have a deleterious effect on device performance. We show that these types of defects can nucleate during epilayer growth from: (1) short segments of edge oriented basal plane dislocations (BPDs) in the substrate which are drawn by glide into the epilayer; and (2) segments of half loops of BPD that are attached to the substrate surface prior to growth which also glide into the epilayer. It is shown that the initial motion of the short edge oriented BPD segments that are drawn from the substrate into the epilayer is caused by thermal stress resulting from radial temperature gradients experienced by the wafer whilst in the epi-chamber. This same stress also causes the initial glide of the surface half-loop into the epilayer and through the advancing epilayer surface. These mobile BPD segments provide screw oriented segments that pierce the advancing epilayer surface that initially replicate as the crystal grows. Once critical thickness is reached, according to the Mathews-Blakeslee model [1], these screw segments glide sideways under the action of the mismatch stress leaving IDs and HLAs in their wake. The origin of the mismatch stress is shown to be associated with lattice parameter differences at the growth temperature, arising from the differences in doping concentration between substrate and epilayer.
Combined Application of Section and Projection Topography to Defect Analysis in PVT-Grown 4H-SiC
- H. Wang, F. Wu, S. Byrappa, S. Shun, B. Raghothamachar, M. Dudley, E. K. Sanchez, G. Chung, D. Hansen, S. G. Mueller, M. J. Loboda
-
- Journal:
- MRS Online Proceedings Library Archive / Volume 1433 / 2012
- Published online by Cambridge University Press:
- 13 June 2012, mrss12-1433-h03-06
- Print publication:
- 2012
-
- Article
- Export citation
-
The combined application of section and projection topography carried out using synchrotron white beam radiation can be a powerful tool for the determination of the three-dimensional configurations of defects in single crystals. In this paper, we present examples of the application of this combination of techniques to the analysis of defect configurations in PVT-grown 4H-SiC wafers cut perpendicular and parallel to the growth axis. Detailed correlation between section and projection topography of threading screw dislocations (TSDs) is presented with particular emphasis being laid on the determination of the signs of the dislocations. Further, information can also be determined regarding the position of the dislocations within the crystal depth. In addition, similar correlation is presented for threading edge dislocations (TEDs) and basal plane dislocations (BPDs). The section topography images of dislocations can comprise direct, intermediary and dynamical contrast and all three types are observed. The application to the study of stacking faults will be also discussed in detail.
Synchrotron Topography Studies of Growth and Deformation-Induced Dislocations in 4H-SiC
- M. Dudley, H. Wang, F. Wu, S. Byrappa, S. Shun, B. Raghothamachar, E. K. Sanchez, G. Chung, D. Hansen, S. G. Mueller, M. J. Loboda
-
- Journal:
- MRS Online Proceedings Library Archive / Volume 1433 / 2012
- Published online by Cambridge University Press:
- 13 June 2012, mrss12-1433-h03-03
- Print publication:
- 2012
-
- Article
- Export citation
-
Synchrotron topography studies are presented of the behavior of growth dislocations and deformation-induced dislocations in 4H-SiC single crystals. The growth dislocations include those in threading orientation with line directions approximately along c with Burgers vectors of a, c, and na+mc (where n and m are integers) while the deformation-induced dislocations include those with line directions confined to the basal plane with Burgers vectors of a and Shockley partial dislocations with Burgers vectors of 1/3<1-100> as well as those with line directions in the {1-100} prismatic planes with Burgers vectors of a. Processes leading to the nucleation of the growth dislocations are discussed as well as their deflection onto the basal plane during crystal growth in a reversible process. This latter process can lead to the conversion of segments of the deflected growth dislocations into deformation induced dislocations. In some cases this can lead to dislocation multiplication via the Hopping Frank-Read source mechanism and in others to the motion of single Shockley partial dislocations leading to Shockley stacking fault expansion. Studies are also presented of interactions between threading growth dislocations with c-component of Burger’s vector facilitated by climb processes which are mediated by interactions with non-equilibrium concentrations of vacancies. This can lead to reactions whereby complete or partial dislocation Burgers vector annihilation occurs.
The Deceleration Capacity - a New Measure of Heart Rate Variability Evaluated in Patients With Schizophrenia and Antipsychotic Treatment
- A. Birkhofer, J. Geissendoerfer, P. Alger, A. Mueller, M. Rentrop, T. Strubel, S. Leucht, H. Förstl, K.-J. Bär, G. Schmidt
-
- Journal:
- European Psychiatry / Volume 28 / Issue 2 / February 2013
- Published online by Cambridge University Press:
- 14 September 2011, pp. 81-86
-
- Article
- Export citation
-
Background
Schizophrenia is associated with increased cardiac mortality. A disturbed autonomic modulation of heart rate (HR) has been described in patients with schizophrenia in whom antipsychotic medication may represent an additional cardiac risk. The novel measure deceleration capacity (DC) of heart rate predicts cardiac mortality in patients with cardiovascular illnesses. The aim of the present paper was to calculate DC in patients with schizophrenia and to compare this measure with established parameters of heart rate variability (HRV).
MethodsHRV and DC were calculated in 24-hour electrocardiogram (ECG) recordings of 20 unmedicated, 40 medicated patients with schizophrenia and 40 controls. As activity has a major influence on HRV, 4-hour periods of “sleep-” and “wake-” ECG were evaluated as additional parameters. Actigraphy was used to ensure comparable levels of activity in patients and controls.
ResultsThe DC as well as the other established HRV measures were not significantly different comparing unmedicated patients with schizophrenia to healthy controls. However, medicated patients showed a significant reduction of DC calculated from ECG recordings during 4 hour over night periods.
ConclusionCalculation of DC might contribute to a better monitoring and identification of an increased risk of cardiac mortality in patients with schizophrenia undergoing antipsychotic treatment.
The science of EChO
- Giovanna Tinetti, James Y-K. Cho, Caitlin A. Griffith, Olivier Grasset, Lee Grenfell, Tristan Guillot, Tommi T. Koskinen, Julianne I. Moses, David Pinfield, Jonathan Tennyson, Marcell Tessenyi, Robin Wordsworth, Alan Aylward, Roy van Boekel, Angioletta Coradini, Therese Encrenaz, Ignas Snellen, Maria R. Zapatero-Osorio, Jeroen Bouwman, Vincent Coudé du Foresto, Mercedes Lopez-Morales, Ingo Mueller-Wodarg, Enric Pallé, Franck Selsis, Alessandro Sozzetti, Jean-Philippe Beaulieu, Thomas Henning, Michael Meyer, Giuseppina Micela, Ignasi Ribas, Daphne Stam, Mark Swain, Oliver Krause, Marc Ollivier, Emanuele Pace, Bruce Swinyard, Peter A.R. Ade, Nick Achilleos, Alberto Adriani, Craig B. Agnor, Cristina Afonso, Carlos Allende Prieto, Gaspar Bakos, Robert J. Barber, Michael Barlow, Peter Bernath, Bruno Bézard, Pascal Bordé, Linda R. Brown, Arnaud Cassan, Céline Cavarroc, Angela Ciaravella, Charles Cockell, Athéna Coustenis, Camilla Danielski, Leen Decin, Remco De Kok, Olivier Demangeon, Pieter Deroo, Peter Doel, Pierre Drossart, Leigh N. Fletcher, Matteo Focardi, Francois Forget, Steve Fossey, Pascal Fouqué, James Frith, Marina Galand, Patrick Gaulme, Jonay I. González Hernández, Davide Grassi, Matt J. Griffin, Ulrich Grözinger, Manuel Guedel, Pactrick Guio, Olivier Hainaut, Robert Hargreaves, Peter H. Hauschildt, Kevin Heng, David Heyrovsky, Ricardo Hueso, Pat Irwin, Lisa Kaltenegger, Patrick Kervella, David Kipping, Geza Kovacs, Antonino La Barbera, Helmut Lammer, Emmanuel Lellouch, Giuseppe Leto, Mercedes Lopez Morales, Miguel A. Lopez Valverde, Manuel Lopez-Puertas, Christophe Lovi, Antonio Maggio, Jean-Pierre Maillard, Jesus Maldonado Prado, Jean-Baptiste Marquette, Francisco J. Martin-Torres, Pierre Maxted, Steve Miller, Sergio Molinari, David Montes, Amaya Moro-Martin, Olivier Mousis, Napoléon Nguyen Tuong, Richard Nelson, Glenn S. Orton, Eric Pantin, Enzo Pascale, Stefano Pezzuto, Ennio Poretti, Raman Prinja, Loredana Prisinzano, Jean-Michel Réess, Ansgar Reiners, Benjamin Samuel, Jorge Sanz Forcada, Dimitar Sasselov, Giorgio Savini, Bruno Sicardy, Alan Smith, Lars Stixrude, Giovanni Strazzulla, Gautam Vasisht, Sandrine Vinatier, Serena Viti, Ingo Waldmann, Glenn J. White, Thomas Widemann, Roger Yelle, Yuk Yung, Sergey Yurchenko
-
- Journal:
- Proceedings of the International Astronomical Union / Volume 6 / Issue S276 / October 2010
- Published online by Cambridge University Press:
- 10 November 2011, pp. 359-370
- Print publication:
- October 2010
-
- Article
-
- You have access Access
- Export citation
-
The science of extra-solar planets is one of the most rapidly changing areas of astrophysics and since 1995 the number of planets known has increased by almost two orders of magnitude. A combination of ground-based surveys and dedicated space missions has resulted in 560-plus planets being detected, and over 1200 that await confirmation. NASA's Kepler mission has opened up the possibility of discovering Earth-like planets in the habitable zone around some of the 100,000 stars it is surveying during its 3 to 4-year lifetime. The new ESA's Gaia mission is expected to discover thousands of new planets around stars within 200 parsecs of the Sun. The key challenge now is moving on from discovery, important though that remains, to characterisation: what are these planets actually like, and why are they as they are?
In the past ten years, we have learned how to obtain the first spectra of exoplanets using transit transmission and emission spectroscopy. With the high stability of Spitzer, Hubble, and large ground-based telescopes the spectra of bright close-in massive planets can be obtained and species like water vapour, methane, carbon monoxide and dioxide have been detected. With transit science came the first tangible remote sensing of these planetary bodies and so one can start to extrapolate from what has been learnt from Solar System probes to what one might plan to learn about their faraway siblings. As we learn more about the atmospheres, surfaces and near-surfaces of these remote bodies, we will begin to build up a clearer picture of their construction, history and suitability for life.
The Exoplanet Characterisation Observatory, EChO, will be the first dedicated mission to investigate the physics and chemistry of Exoplanetary Atmospheres. By characterising spectroscopically more bodies in different environments we will take detailed planetology out of the Solar System and into the Galaxy as a whole.
EChO has now been selected by the European Space Agency to be assessed as one of four M3 mission candidates.
Contributors
-
- By Hideki Azuma, Susan Mary Benbow, Bettina Heike Bewernick, T. K. Birkenhäger, Hal Blumenfeld, Tom G. Bolwig, Stanley N. Caroff, Sidney S. Chang, Pinhas N. Dannon, Renana Eitan, Alan R. Felthous, Felipe Fregni, Gabor Gazdag, Nataliya Giagou, Mustafa M. Husain, Charles H. Kellner, Barry Alan Kramer, Galit Landshut, James Stuart Lawson, Bernard Lerer, Jerry Lewis, Dongchen Li, Colleen Loo, Michelle Magid, Stephan C. Mann, Limore Maron, W. Vaughn McCall, Shawn M. McClintock, Niall McCrae, Andrew McDonald, Nikolaus Michael, Paul S. Mueller, Alexander I. Nelson, Unnati D. Patel, Kathy Peng, Keith G. Rasmussen, William H. Reid, Joseph M. Rey, Barbara M. Rohland, Marina Odebrecht Rosa, Moacyr Alexandro Rosa, Oded Rosenberg, Peter B. Rosenquist, Thomas E. Schläpfer, Edward Shorter, Pascal Sienaert, Conrad M. Swartz, Kenneth Trevino, Gabor S. Ungvari, Walter W. van den Broek, Garry Walter, Julie A. Williams
- Edited by Conrad M. Swartz
-
- Book:
- Electroconvulsive and Neuromodulation Therapies
- Published online:
- 15 July 2009
- Print publication:
- 02 March 2009, pp ix-xiv
-
- Chapter
- Export citation