202 research outputs found
Differences in Radiative Forcing, Not Sensitivity, Explain Differences in Summertime Land Temperature Variance Change Between CMIP5 and CMIP6
No full text© The Author(s), 2022. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Chan, D., Rigden, A., Proctor, J., Chan, P. W., & Huybers, P. Differences in radiative forcing, not sensitivity, explain differences in summertime land temperature variance change between CMIP5 and CMIP6. Earth’s Future, 10(2), (2022): e2021EF002402, https://doi.org/10.1029/2021EF002402.How summertime temperature variability will change with warming has important implications for climate adaptation and mitigation. CMIP5 simulations indicate a compound risk of extreme hot temperatures in western Europe from both warming and increasing temperature variance. CMIP6 simulations, however, indicate only a moderate increase in temperature variance that does not covary with warming. To explore this intergenerational discrepancy in CMIP results, we decompose changes in monthly temperature variance into those arising from changes in sensitivity to forcing and changes in forcing variance. Across models, sensitivity increases with local warming in both CMIP5 and CMIP6 at an average rate of 5.7 ([3.7, 7.9]; 95% c.i.) × 10−3°C per W m−2 per °C warming. We use a simple model of moist surface energetics to explain increased sensitivity as a consequence of greater atmospheric demand (∼70%) and drier soil (∼40%) that is partially offset by the Planck feedback (∼−10%). Conversely, forcing variance is stable in CMIP5 but decreases with warming in CMIP6 at an average rate of −21 ([−28, −15]; 95% c.i.) W2 m−4 per °C warming. We examine scaling relationships with mean cloud fraction and find that mean forcing variance decreases with decreasing cloud fraction at twice the rate in CMIP6 than CMIP5. The stability of CMIP6 temperature variance is, thus, a consequence of offsetting changes in sensitivity and forcing variance. Further work to determine which models and generations of CMIP simulations better represent changes in cloud radiative forcing is important for assessing risks associated with increased temperature variance.This study was supported by the Harvard Global Institute and NSF (Award 1903657). D. Chan was also supported by the Woods Hole Oceanographic Institute Weston Howland Jr. Postdoctoral Fellowship
Keeping objects live
No full textIt is often assumed that museum exhibits are inert but, in contrast to artifacts in most mainstream institutions, those at the Museum of Witchcraft, The Valiant Soldier community museum, and the Dartmoor Prison Museum are felt to be fully functioning and, to some extent, potent or dangerous. In order to consider why this is the case, this essay investigates how museums are considered to “kill off” their exhibits and why this process does not occur in these small, independent organizations. Notably, the three venues have few or no paid members of staff and limited opportunities for gaining state funding. Operating largely independently of the public sector, they have no need to adopt official priorities and in consequence their modes of practice differ from those encountered in major institutions. They also have close links to their immediate location and communities. Focusing on these museums therefore raises the possibility that the “death” of objects is not a necessary condition but that their demise depends upon the specific character and circumstances of display
The synthesis of monodisperse alkanes with long chains
No full textThis thesis discusses reasons for the interest in monodisperse long chain alkanes and describes attempts, past and present, to synthesise such molecules. Chapter 1 discusses why the synthesis of such molecules are important and the objectives of this project. Chapter 2 reviews the methods previous groups have devised to prepare pure samples of long chain alkanes. In particular, work carried out by Whiting et al. at Bristol, whose scheme formed the basis of the early work in Durham. Chapter 3 describes the work in Durham and improvements which were made to Whiting's method, allowing the synthesis of longer chain lengths and greater quantities of materials to be achieved. Chapter 4 provides a summary of the practical work carried out by the author. Chapter 5 gives experimental details of the work described in Chapter 4
Straw Hat Players programs, 1992 (1992)
No full textMicheal Brannan, Jeffrey D. Boyd, Amber Carlsgaard, Karl L. G. Crose, Jennifer R. Daly, Dayna Del Val, Todd Denning, Edia A. Durdin, Dan W. Erickson, Elizabeth A. Evert, Nicole Fenstad, Patricia Fike, David M. Filmore, jr., Michael Garver, Michael J. Hance, Bryndis Hovde, Jarrod D. Iversen, Chadwyn Knutson, Jay Kopita, Betsy Kruse, Randy E. Long, Michael Messano, Lisa Moes, Dan Moore, Betsi Morrison, R. Anne Nelson, Timothy N. Nelson, Paul Neumann, Jeffrey Nibbe, Susan Nickel, Susan M. Pederson, Mary M. Pelletier, John Peters, J. Caleb Peterson, Libby Pitts, John Proctor III, Leah Roy, Jeremy A. Simonson, Joey Siti, Nancy Spiegel, Toby Sprague, Kay Sterner, Doreen S. Thorson, Dean Tschider, Aasne Vigesaa, C. Patrick Ward, Matthew P. Weil, Jennifer Weir, Michael Wildehttps://red.mnstate.edu/shp_programs/1027/thumbnail.jp
Effects of fir-wood biochar on CH4 oxidation rates and methanotrophs in landfill cover soils packed at three different proctor compaction levels
No full textApplication of biochar to landfill cover soils can purportedly improve methane (CH4) oxidation rates, but understanding the combined effects of soil texture, compaction, and biochar on the activity and composition of the methanotrophs is limited. The amendment of wood biochar on two differently textured landfill cover soils at three compaction levels of the Proctor density was explored by analyzing changes in soil physical properties relevant to methane oxidation, the effects on CH4 oxidation rates, and the composition of the methanotrophic community. Loose soils with and without biochar were pre-incubated to equally elevate the CH4 oxidation rates. Hereafter, soils were compacted and re-incubated. Methane oxidation rates, gas diffusivity, water retention characteristics, and pore size distribution were analyzed on the compacted soils. The relative abundance of methanotrophic bacteria (MOB) was determined at the end of both the pre-incubation and incubation tests of the packed samples. Biochar significantly increased porosity at all compaction levels, enhancing diffusion coefficients. Also, a re-distribution in pore sizes was observed. Increased gas diffusivity from low compaction and amendment of biochar, though, did not reflect higher methane oxidation rates due to high diffusive oxygen fluxes over the limited height of the compacted soil specimens. All soils, with and without biochar, were strongly dominated by Type II methanotrophs. In the sandy soil, biochar amendment strongly increased MOB abundance, which could be attributed to a corresponding increase in the relative abundance of Methylocystis species, while no such response was observed in the clayey soil. Compaction did not change the community composition in either soil. Fir-wood biochar addition to landfill cover soils may not always enhance methanotrophic activity and hence reduce fugitive methane emissions, with the effect being soil-specific. However, especially in finer and more compacted soils, biochar amendment can maintain soil diffusivity above a critical level, preventing the collapse of methanotrophy.Geo-engineeringLarge Scale Energy StoragePattern Recognition and Bioinformatic
The formation history of the Galactic bulge
No full textThe distributions of the stellar metallicities of K giant stars in several fields of the Galactic bulge, taken from the literature and probing projected Galactocentric distances of similar to500 pc to similar to3 kpc, are compared with a simple model of star formation and chemical evolution. Our model assumes a Schmidt law of star formation and is described by only a few parameters that control the infall and outflow of gas and the star formation efficiency. Exploring a large volume of parameter space, we find that very short infall time-scales are needed (less than or similar to0.5 Gyr), with durations of infall and star formation greater than 1 Gyr being ruled out at the 90 per cent confidence level. The metallicity distributions are compatible with an important amount of gas and metals being ejected in outflows, although a detailed quantification of the ejected gas fraction is strongly dependent on a precise determination of the absolute stellar metallicities. We find a systematic difference between the samples of Ibata & Gilmore, at projected distances of 1-3 kpc, and the sample in Baade's window (Sadler et al.). This could be caused either by a true metallicity gradient in the bulge or by a systematic offset in the calibration of [Fe/H] between these two samples. This offset does not play an important role in the estimate of infall and formation time-scales, which are mostly dependent on the width of the distributions. The recent bulge data from Zoccali et al. are also analysed, and the subsample with subsolar metallicities still rules out infall time-scales greater than or similar to1 Gyr at the 90 per cent confidence level. Hence, the short time-scales we derive based on the observed distribution of metallicities are robust and should be taken as stringent constraints on bulge formation models
Secondary Literacy Across the Curriculum
No full textThis paper discusses the challenges and possibilities attendant upon successfully implementing literacy across the curriculum initiatives – or ‘school language policies’ as they have come to be known – particularly at the secondary or high school level. It provides a theoretical background to these issues, exploring previous academic discussions of school language policies, and highlights key areas of concern as well as opportunity with respect to school implementation of such policies. As such, it provides a necessary conceptual background to the subsequent papers in this special issue, which focus upon the Secondary Schools’ Literacy Initiative (SSLI) – a New Zealand funded programme that aims to establish cross-curricular language and literacy policies in secondary schools
Agnotology
No full textRobert Proctor e Ian Bolin acuñaron el término agnotología para designar el estudio de la ignorancia. Este escrito propone superar la visión de la ignorancia como un vacío que puede ser llenado por el conocimiento e invita a pensar en las formas en que hoy se produce, en forma premeditada y estructural: por negligencia, miopía, secreto o supresión. El autor muestra que la creación deliberada de la ignorancia es una estrategia para engañar y sembrar dudas sobre los hechos observados y sobre el conocimiento científico, tomando como ejemplos el papel de los secretos comerciales, la actividad de las tabacaleras para negar la relación causal entre el consumo de cigarrillos y el cáncer y el papel del secreto militar. Por último analiza algunos casos en que la ignorancia es una expresión de valores morales, como la prohibición, en algunas universidades, de investigaciones cuyo único fin es el afán de lucro y, en algunas revistas científicas, de publicar trabajos financiados por ciertas fuentes, así como el rechazo de ciertas tecnologías por razones intelectuales y morales bien fundadas.Robert Proctor and Ian Bolin coined the term agnotology to designate the study of ignorance. This paper proposes to overcome the vision of ignorance as a void that can be filled by knowledge and invites us to think about the ways in which it is produced today, in a premeditated and structural way: through negligence, myopia, secrecy or suppression. The author shows that the deliberate creation of ignorance is a strategy to compromise and sow doubts about the observed facts and about scientific knowledge, taking as examples the role of trade secrets, the activity of tobacco companies to deny the causal relationship between the cigarette smoking and cancer and the role of military secret. Finally, some cases in ignorance is an expression of moral values, such as the prohibition, in some universities, of research whose sole purpose is the profit motive and, in some scientific journals, of publishing works financed by certain sources, as well as the rejection of certain technologies for well-founded intellectual and moral reasons
Agnotologia
No full textRobert Proctor and Ian Bolin coined the term agnotology to designate the study of ignorance. This paper proposes to overcome the vision of ignorance as a void that can be filled by knowledge and invites us to think about the ways in which it is produced today, in a premeditated and structural way: through negligence, myopia, secrecy or suppression. The author shows that the deliberate creation of ignorance is a strategy to compromise and sow doubts about the observed facts and about scientific knowledge, taking as examples the role of trade secrets, the activity of tobacco companies to deny the causal relationship between the cigarette smoking and cancer and the role of military secret. Finally, some cases in ignorance is an expression of moral values, such as the prohibition, in some universities, of research whose sole purpose is the profit motive and, in some scientific journals, of publishing works financed by certain sources, as well as the rejection of certain technologies for well-founded intellectual and moral reasons.Robert Proctor e Ian Bolin acuñaron el término agnotología para designar el estudio de la ignorancia. Este escrito propone superar la visión de la ignorancia como un vacío que puede ser llenado por el conocimiento e invita a pensar en las formas en que hoy se produce, en forma premeditada y estructural: por negligencia, miopía, secreto o supresión. El autor muestra que la creación deliberada de la ignorancia es una estrategia para engañar y sembrar dudas sobre los hechos observados y sobre el conocimiento científico, tomando como ejemplos el papel de los secretos comerciales, la actividad de las tabacaleras para negar la relación causal entre el consumo de cigarrillos y el cáncer y el papel del secreto militar. Por último analiza algunos casos en que la ignorancia es una expresión de valores morales, como la prohibición, en algunas universidades, de investigaciones cuyo único fin es el afán de lucro y, en algunas revistas científicas, de publicar trabajos financiados por ciertas fuentes, así como el rechazo de ciertas tecnologías por razones intelectuales y morales bien fundadas.Robert Proctor e Ian Bolin cunharam o termo agnotologia para designar o estudo da ignorância. Este artigo propõe-se a superar a visão da ignorância como um vazio que pode ser preenchido pelo conhecimento e nos convida a pensar sobre as maneiras pelas quais é produzido hoje, de maneira premeditada e estrutural: por negligência, miopia, sigilo ou supressão. O autor mostra que a criação deliberada da ignorância é uma estratégia para enganar e semear dúvidas sobre os fatos observados e sobre o conhecimento científico, tomando como exemplo o papel dos segredos comerciais, a atividade das empresas de tabaco em negar a relação causal entre os tabagismo e câncer e o papel do segredo militar. Por fim, analisa alguns casos em que a ignorância é uma expressão de valores morais, como a proibição, em algumas universidades, de pesquisas cujo único objetivo é o lucro e, em algumas revistas científicas, a publicação de obras financiadas por determinadas fontes, como a rejeição de certas tecnologias por razões intelectuais e morais bem fundamentadas
Environment and self-regulation in galaxy formation
No full textThe environment is known to affect the formation and evolution of galaxies considerably best visible through the well-known morphology–density relationship. It is less clear, though, whether the environment is equally important at a given galaxy morphology. In this paper, we study the effect of environment on the evolution of early-type galaxies as imprinted in the fossil record by analysing the stellar population properties of 3360 galaxies morphologically selected by visual inspection from the Sloan Digital Sky Survey in a narrow redshift range ( 0.05 ≤z≤ 0.06 ). The morphological selection algorithm is critical, as it does not bias against recent star formation. We find that the distribution of ages is bimodal with a strong peak at old ages and a secondary peak at young ages around ∼2.5 Gyr containing about 10 per cent of the objects. This is an analogue to 'red sequence' and 'blue cloud' identified in galaxy populations usually containing both early- and late-type galaxies. The fraction of the young, rejuvenated galaxies increases with both decreasing galaxy mass and decreasing environmental density up to about 45 per cent, which implies that the impact of environment increases with decreasing galaxy mass. The rejuvenated galaxies have lower α/Fe ratios than the average and most of them show signs of ongoing star formation through their emission line spectra. All objects that host active galactic nuclei in their centres without star formation are part of the red sequence population. We confirm and statistically strengthen earlier results that luminosity weighted ages, metallicities and α/Fe element ratios of the red sequence population correlate well with velocity dispersion and galaxy mass. Most interestingly, however, these scaling relations are not sensitive to environmental densities and are only driven by galaxy mass. We infer that early-type galaxy formation has undergone a phase transition a few billion years ago around z∼ 0.2 . A self-regulated formation phase without environmental dependence has recently been superseded by a rejuvenation phase, in which the environment plays a decisive role possibly through galaxy mergers and interactions
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