Response of Arctic ozone to sudden stratospheric warmings

Sudden stratospheric warmings (SSWs) are the main source of intra-seasonal and interannual variability in the extratropical stratosphere. The profound alterations to the stratospheric circulation that accompany such events produce rapid changes in the atmospheric composition. The goal of this study is to deepen our understanding of the dynamics that control changes of Arctic ozone during the life cycle of SSWs, providing a quantitative analysis of advective transport and mixing. We use output from four ensemble members (60 years each) of the Whole Atmospheric Community Climate Model version 4 performed for the Chemistry Climate Model Initiative and also use reanalysis and satellite data for validation purposes. The composite evolution of ozone displays positive mixing ratio anomalies of up to 0.5–0.6&thinsp;ppmv above 550&thinsp;K ( ∼ &thinsp;50&thinsp;hPa) around the central warming date and negative anomalies below (−0.2 to −0.3&thinsp;ppmv), consistently in observations, reanalysis, and the model. Our analysis shows a clear temporal offset between ozone eddy transport and diffusive ozone fluxes. The initial changes in ozone are mainly driven by isentropic eddy fluxes linked to enhanced wave drag responsible for the SSW. The recovery of climatological values in the aftermath of SSWs is slower in the lower than in the upper stratosphere and is driven by the competing effects of cross-isentropic motions (which work towards the recovery) and isentropic irreversible mixing (which delays the recovery). These features are enhanced in strength and duration during sufficiently deep SSWs, particularly those followed by polar-night jet oscillation (PJO) events. It is found that SSW-induced ozone concentration anomalies below 600&thinsp;K ( ∼ &thinsp;40&thinsp;hPa), as well as total column estimates, persist around 1 month longer in PJO than in non-PJO warmings.</p

Beetle and plant arrow poisons of the Ju|’hoan and Hai||om San peoples of Namibia (Insecta, Coleoptera, Chrysomelidae; Plantae, Anacardiaceae, Apocynaceae, Burseraceae)

The use of archery to hunt appears relatively late in human history. It is poorly understood but the application of poisons to arrows to increase lethality must have occurred shortly after developing bow hunting methods; these early multi-stage transitions represent cognitive shifts in human evolution. This paper is a synthesis of widely-scattered literature in anthropology, entomology, and chemistry, dealing with San (“Bushmen”) arrow poisons. The term San (or Khoisan) covers many indigenous groups using so-called ‘click languages’ in southern Africa. Beetles are used for arrow poison by at least eight San groups and one non-San group. Fieldwork and interviews with Ju|’hoan and Hai||om hunters in Namibia revealed major differences in the nature and preparation of arrow poisons, bow and arrow construction, and poison antidote. Ju|’hoan hunters use leaf-beetle larvae of Diamphidia Gerstaecker and Polyclada Chevrolat (Chrysomelidae: Galerucinae: Alticini) collected from soil around the host plants Commiphora africana (A. Rich.) Engl. and Commiphora angolensis Engl. (Burseracaeae). In the Nyae Nyae area of Namibia, Ju|’hoan hunters use larvae of Diamphidia nigroornata Ståhl. Larvae and adults live above-ground on the plants and eat leaves, but the San collect the underground cocoons to extract the mature larvae. Larval hemolymph is mixed with saliva and applied to arrows. Hai||om hunters boil the milky plant sap of Adenium bohemianum Schinz (Apocynaceae) to reduce it to a thick paste that is applied to their arrows. The socio-cultural, historical, and ecological contexts of the various San groups may determine differences in the sources and preparation of poisons, bow and arrow technology, hunting behaviors, poison potency, and perhaps antidotes

Monge Distance between Quantum States

We define a metric in the space of quantum states taking the Monge distance between corresponding Husimi distributions (Q--functions). This quantity fulfills the axioms of a metric and satisfies the following semiclassical property: the distance between two coherent states is equal to the Euclidean distance between corresponding points in the classical phase space. We compute analytically distances between certain states (coherent, squeezed, Fock and thermal) and discuss a scheme for numerical computation of Monge distance for two arbitrary quantum states.Comment: 9 pages in LaTex - RevTex + 2 figures in ps. submitted to Phys. Rev.

Study and application of the balloon frame system to the industrialization of housing: the case of the American System-Built Houses of Frank Lloyd Wright

[EN] Within his large architectural production, Frank Lloyd Wright had the opportunity to experiment with the timber industrialization, linking a traditional material with the modern sense of architecture. Wood and Frank Lloyd Wright are inseparable from the balloon frame system, a system which he will use at his first housing and through which he will materialize the spatial decomposition concept. The research on the particular American System-Built Houses case will serve to show the earliest experiences of Wright with the industry, whose conclusions he would use for subsequent researches on prefabrication.[ES] Dentro de su extensa producción arquitectónica, Frank Lloyd Wright tuvo ocasión para experimentar con la industrialización de la madera, trabando un material tradicional con el sentido moderno de la arquitectura. La madera y Frank Lloyd Wright son inseparables del sistema balloon frame, sistema que utilizará en sus primeras viviendas y a través del cual materializará su concepto de descomposición espacial. La investigación del caso concreto de las American System-Built Houses servirá para mostrar las experiencias más tempranas de Wright con la industria, cuyas conclusiones utilizaría para sus posteriores investigaciones sobre prefabricación.Serra Soriano, B.; Díaz Segura, AL.; Meri De La Maza, RM. (2017). Estudio y aplicación del sistema balloon frame a la industrialización de la vivienda: el caso de las American System-Built Houses de Frank Lloyd Wright. Informes de la Construcción. 69(546):1-11. doi:10.3989/ic.15.023S11169546(1) Sanz Esquide, J. A. (1990). Frank Lloyd Wright, p. 10, Barcelona: Ediciones del Serbal.(2) Hitchcock, H.-R. (1978). Frank Lloyd Wright. Obras 1887-1941, p. 66, Barcelona: Editorial Gustavo Gili.(3) Hitchcock, H.-R. (1978). Frank Lloyd Wright. Obras 1887-1941, p. 67, Barcelona: Editorial Gustavo Gili.(4) Hitchcock, H.-R. (1990). Frank Lloyd Wright y la tradición académica de principios de la década de 1890. En Sanz Esquide, J. A., Frank Lloyd Wright (p. 55). Barcelona: Ediciones del Serbal.(5) Seligmann, W. (1991). Evolution of the Prairie House. En McCarter, R. (Ed.), A Primer on Architectural Principles (p. 60). New York: Princeton Architectural Press.(6) Wright, F. Ll. (1998). Autobiografía 1867 [1944], p. 159, Madrid: El Croquis Editorial.(7) Wright, F. Ll. (1998). Autobiografía 1867 [1944], pp. 176-180, Madrid: El Croquis Editorial.(8) Scully, V. (1990). Frank Lloyd Wright y la estofa de los sue-os. En Sanz Esquide, J. A., Frank Lloyd Wright (p. 58). Barcelona: Ediciones del Serbal.(9) Norberg-Schulz, C. (2005). Los principios de la arquitectura moderna, p. 54, Barcelona: Editorial Reverté.(10) Wright, F. Ll. (1954). The natural house, p. 181, New York: Horizon Press.(11) Wright, F. Ll. (2010). Arquitectura moderna. The Kahn Lectures. Princeton 1930, p. 113, Madrid: Paidós Estética.(12) Wright, F. Ll. (2010). Arquitectura moderna. The Kahn Lectures. Princeton 1930, p. 140, Madrid: Paidós Estética.(13) Wright, F. Ll. (1998). Autobiografía 1867 [1944], p. 280, Madrid: El Croquis Editorial.(14) Martín-Saiz, D. (2013). Jaroslav J. Polivka y el Guggenheim Museum de New York. Informes de la Construcción, 65(531): 261-274.(15) Kaufmann, E. (1998). Frank Lloyd Wright. An american architecture, pp. 108-109, Arizona: The Frank Lloyd Wright Foundation.(16) Giedion, S. (1967). Space, time and architecture, pp. 353-354, Cambridge: Harvard University Press.(17) Field, W. (1942). A reexamination into the invention of the balloon frame. Journal of the American Society of Architectural Historians, 2(4): 3-29.(18) Sprague, P. E. (1981). The origin of balloon framing. Journal of the American Society of Architectural Historians, 40(4): 311-319.(19) Woodward, G. E., Woodward, F. W. (1865). Woodward's Country Homes, New York: Stephen Hallet, Printer.(20) Turan, M. (2009). Reconstructing the balloon frame: a study in the history of architectonics. Journal of the Faculty of Architecture of the Middle East Technical University, 26(2): 175-209.21. Bergdoll, B., Christensen, P. (2008). Home delivery: fabricating the modern dwelling, p. 41, New York: The Museum of Modern Art.(22) Sprague, P. E. (1983). Chicago Balloon Frame. En Jandl, H. W., The Technology of Historic American Buildings: Studies of The Materials, Craft Processes, and The Mechanization of Building Construction (pp. 35-36). Washington, DC: Foundation for Preservation Technology.(23) Woodward, G. E., Woodward, F. W. (1865). Woodward's Country Homes, p. 166, New York: Stephen Hallet, Printer.24. Bergdoll, B., Christensen, P. (2008). Home delivery: fabricating the modern dwelling, p. 48, New York: The Museum of Modern Art.(25) Wright, F. Ll. (1998). Autobiografía 1867 [1944], p. 280, Madrid: El Croquis Editorial.(26) McCarter, R. (1997). Frank Lloyd Wright. Architect, p. 240, London: Phaidon Press Limited.(27) Samuelson, T. (1993). American System Built Houses designed by Frank Lloyd Wright. 10410 and 10541 South Hoyne Avenue, pp. 10-14, Chicago: Department of Planning and Development.(28) Storrer, W. A. (2006). The Frank Lloyd Wright Companion, p. 202, Chicago: The University Chicago Press.(29) Ford, E. R. (1990). The Details of Modern Architecture, vol. 1, p. 325, Cambridge: The MIT Press.30. Brooks Pfeiffer, B. (2011). Frank Lloyd Wright: the complete Works, vol. 1, 1885-1916, p. 519, Köln: TASCHEN GmbH.(31) Dow, A. B. (1963). The continuity of idea and form. En Placzek, A. K., Four great makers of modern architecture (p. 25). New York: Da Capo Press.(32) Wright, F. Ll. (1998). Autobiografía 1867 [1944], p. 183, Madrid: El Croquis Editorial

The tip cross-sectional areas of poisoned bone arrowheads from southern Africa

Abstract: Current hunter-gatherers from the Kalahari in southern Africa are well-known for their use of poisoned arrowheads, and it is assumed that this tradition spanned most of the Holocene in the region. Recent archaeological work, however, indicates that the techno-behaviour may have originated sometime during the Pleistocene. Tracing the use of poisoned arrowheads through time is not an easy task. Here I explore the use of the tip cross-sectional area (TSCA) metric to analyse relatively large samples of bone points that are ethno-historically associated with Kalahari San poisoned arrow hunting. I add the southern African poisoned bone arrowhead TSCA range to the previous ranges established for North American atlatl dart tips, North American arrowheads and large thrusting spears. Based on the results obtained from 445 artefacts spanning historical, Later and Middle Stone Age phases, I show that poisoned bone arrowheads may have been in use in southern Africa throughout the last 60 000 years, and that a methodical effort to trace stone-tipped poison arrowheads may be warranted

Pre-emption cases may support, not undermine, the counterfactual theory of causation

Pre-emption cases have been taken by almost everyone to imply the unviability of the simple counterfactual theory of causation. Yet there is ample motivation from scientific practice to endorse a simple version of the theory if we can. There is a way in which a simple counterfactual theory, at least if understood contrastively, can be supported even while acknowledging that intuition goes firmly against it in pre-emption cases – or rather, only in some of those cases. For I present several new pre-emption cases in which causal intuition does not go against the counterfactual theory, a fact that has been verified experimentally. I suggest an account of framing effects that can square the circle. Crucially, this account offers hope of theoretical salvation – but only to the counterfactual theory of causation, not to others. Again, there is (admittedly only preliminary) experimental support for this account

Synthesis and reductive chemistry of bimetallic and trimetallic rare-earth metallocene hydrides with (C5H4SiMe3)1− ligands

The reductive chemistry of [Cp\u272Ln(μ–H)(THF)x]y [Ln = Y, Dy, Tb; Cp\u27 = (C5H4SiMe3)1−; x = 2, 0 and y = 2, 3] was examined to determine if these hydrides would be viable precursors for 4fn5d1 Ln2+ ions that could form 5d1-5d1 metal–metal bonded complexes. The hydrides were prepared by reaction of the chlorides, [Cp\u272Ln(μ–Cl)]2, 1-Ln, with allylmagnesium chloride to form the allyl complexes, [Cp\u272Y(η3–C3H5)(THF)], 2-Ln, which were hydrogenolyzed. The solvent-free reaction of solid 2-Ln with 60 psi of H2 gas in a Fischer-Porter apparatus produced, in the Y case, the trimetallic species, [Cp\u272Y(μ–H)]3, 3-Y, and in the Dy and Tb cases, the bimetallic complexes [Cp\u272Ln(μ–H)(THF)]2, 4-Ln (Ln = Dy, Tb). The latter complexes could be converted to 3-Dy and 3-Tb by heating under vacuum. Isopiestic data indicate that 3-Y solvates to 4-Y in THF. Reductions of 4-Y, 4-Dy, and 4-Tb with KC8 in the presence of a chelate such as 2.2.2-cryptand or 18-crown-6 all gave reaction products with intense dark colors characteristic of Ln2+ ions. In the yttrium case, with either chelating agent, the dark green product gives a rhombic EPR spectrum (g1 = 2.01, g2 = 1.99, g3 = 1.98, A = 24.1 G) at 77 K. However, the only crystallographically-characterizable products obtainable from these solutions were Ln3+polyhydride anion complexes of composition, [K(chelate)]{[Cp\u272Ln(μ–H)]3(μ–H)}

Insulin-like growth factor-I binds in the inner plexiform layer and circumferential germinal zone in the retina of the goldfish

Results of the previous study suggest that insulin-related peptides regulate proliferation of retinal progenitors in the adult goldfish. Because of their known roles in retinal neurogenesis, we have chosen to focus future studies on insulin-like growth factor I (IGF-I) and the IGF-I receptor. In the study described here, we characterized the spatial distribution and specificity of IGF-I binding sites in the retina of the adult goldfish by performing receptor-binding autoradiography with [ 125 I]-IGF-I alone and with unlabeled IGF-I-related molecules (IGF-I, IGF-II, insulin, and des-[1-3]-IGF-I) as competitive inhibitors of [ 125 I]-IGF-I binding. The results of these experiments show that IGF-I binds in two locations in the retina of the adult goldfish, within the inner plexiform layer of the differentiated retina and the circumferential germinal zone. The competition experiments suggest that [ 125 I]-IGF-I binds at sites specific for IGF-I, and that both IGF-I receptors and IGF-I binding proteins are present in the retina. J. Comp. Neurol. 394:395–401, 1998. © 1998 Wiley-Liss, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/34449/1/10_ftp.pd

An integrated pharmacokinetic and pharmacodynamic study of a new drug of abuse, methylone, a synthetic cathinone sold as 'bath salts'

Material and methods. Methylone was administered to male Sprague-Dawley rats intravenously (10 mg/kg) and orally (15 and 30 mg/kg). Plasma concentrations and metabolites were characterized by LC/MS and LC-MS/MS fragmentation patterns. Locomotor activity was monitored for 180-240 min. Results. Oral administration of methylone induced a dose-dependent increase in locomotor activity in rats. The plasma concentrations after i.v. administration were described by a two-compartment model with distribution and terminal elimination phases of α = 1.95 h− 1 and β = 0.72 h− 1. For oral administration, peak methylone concentrations were achieved between 0.5 and 1 h and fitted to a flip-flop model. Absolute bioavailability was about 80% and the percentage of methylone protein binding was of 30%. A relationship between methylone brain levels and free plasma concentration yielded a ratio of 1.42 ± 0.06, indicating access to the central nervous system. We have identified four Phase I metabolites after oral administration. The major metabolic routes are N-demethylation, aliphatic hydroxylation and O-methylation of a demethylenate intermediate. Discussion. Pharmacokinetic and pharmacodynamic analysis of methylone showed a correlation between plasma concentrations and enhancement of the locomotor activity. A contribution of metabolites in the activity of methylone after oral administration is suggested. Present results will be helpful to understand the time course of the effects of this drug of abuse in humans

Emergence of comparable covalency in isostructural cerium(IV)- and uranium(IV)-carbon multiple bonds

We report comparable levels of covalency in cerium- and uranium-carbon multiple bonds in the isostructural carbene complexes [M(BIPMTMS)(ODipp)2] [M = Ce (1), U (2), Th (3); BIPMTMS = C(PPh2NSiMe3)2; Dipp = C6H3-2,6-Pri2] whereas for M = Th the M=C bond interaction is much more ionic. On the basis of single crystal X-ray diffraction, NMR, IR, EPR, and XANES spectroscopies, and SQUID magnetometry complexes 1-3 are confirmed formally as bona fide metal(IV) complexes. In order to avoid the deficiencies of orbital-based theoretical analysis approaches we probed the bonding of 1-3 via analysis of RASSCF- and CASSCF-derived densities that explicitly treats the orbital energy near-degeneracy and overlap contributions to covalency. For these complexes similar levels of covalency are found for cerium(IV) and uranium(IV), whereas thorium(IV) is found to be more ionic, and this trend is independently found in all computational methods employed. The computationally determined trends in covalency of Ce ~ U > Th are also reproduced in experimental exchange reactions of 1-3 with MCI4 salts where 1 and 2 do not exchange with ThCl4, but 3 does exchange with MCl4 (M = Ce, U) and 1 and 2 react with UCl4 and CeCl4, respectively, to establish equilibria. This study therefore provides complementary theoretical and experimental evidence that contrasts to the accepted description that generally lanthanide-ligand bonding in non-zero oxidation state complexes is overwhelmingly ionic but that of uranium is more covalent