Science and Technology

1. Using the two electrode voltage clamp configuration, a high voltage activated whole-cell Ca2+ channel current (IBa) was recorded from a cluster of neurosecretory ‘Light Yellow’ Cells (LYC) in the right parietal ganglion of the pond snail Lymnaea stagnalis. 2. Recordings of IBa from LYCs show a reversible concentration-dependent depression of current amplitude in the presence of the volatile anaesthetics halothane, isoflurane and sevoflurane, or the non-volatile anaesthetic pentobarbitone at clinical concentrations. 3. In the presence of the anaesthetics investigated, IBa measured at the end of the depolarizing test pulse showed proportionally greater depression than that at measured peak amplitude, as well as significant decrease in the rate of activation or increase in inactivation or both. 4. Within the range of concentrations used, the concentration-response plots for all the anaesthetics investigated correlate strongly to straight line functions, with linear regression R2 values > 0.99 in all instances. 5. For volatile anaesthetics, the dose-response regression slopes for IBa increase in magnitude, in order of gradient: sevoflurane, isoflurane and halothane, a sequence which reflects their order of clinical potency in terms of MAC value."

In the four decades straddling the turn of the nineteenth century, the small Ontario town of Niagara-on-the-Lake experienced marked growth in its tourism industry. Catering predominantly to wealthy upper-middle-class Canadian and American visitors, the lake-side settlement offered numerous opportunities for polite recreation. Chief among them was lawn tennis, a sport that sat somewhat outside of the mainstream in terms of its high-class, mixed-sex participation demographic. While its players were imbued with a strong amateur philosophy, local boosters recognized the sport’s potential to generate tourism income through its two tournaments, but this hinged on the outward presentation among its players/guests of refined gentility—a reflection of both class and gender—both on and off the court. This article considers how lawn tennis tournaments fit into the town’s burgeoning tourism industry, and examines gender relations—particularly the role of women—in relation to this development.

This article examines the connections between (lawn) tennis in Britain and the Great War (1914–1918). While previous historical research has suggested a four-year hiatus, in fact the sport continued to be played during the war, recreationally and among servicemen/women and more elite players in exhibition matches. Anecdotes about the cessation of tournaments and restricted play were interspersed with debates about the appropriateness of continuing play recreationally, as the ‘gentleman in tennis flannels’ became a symbol of public censure. Alongside enlistment, tennis players responded to the call byoffering their club facilities to the war effort, digging up courts to plant vegetables, hosting charity matches, and providing entertainment for convalescent soldiers. This analysis highlights the significance of tennis as a vehicle to promote a kind of British identity, as responses to the war as seen through tennis reflected broader sporting ideals, privileging amateurism, fair play and the ‘stuff upper lip’.

Sport continues to be one of the primary means through which notions of Englishness and Britishness are constructed, contested, and resisted. The legacy of the role of sport in the colonial project of the British Empire, combined with more recent connections between sport and far right fascist/nationalist politics, has made the association between Britishness, Englishness, and ethnic identity(ies) particularly intriguing. In this paper, these intersections are explored through British media coverage of the Canadian-born, British tennis player, Greg Rusedski. This coverage is examined through the lens of ‘performativity,’ as articulated by Judith Butler. Through a critical application of Butler's ideas, the ways in which the media seek to recognise and normalise certain identities, while problematising and excluding others, can be more fully appreciated. Thus, it was within newspaper framings of Rusedski that hegemonic notions of White Englishness could be performed, maintained, and embedded.

Heavy‐atom substitution chemistry in donor–acceptor (D–A) conjugated polymers has gained increasing attention in the past few years. Overall, the introduction of “heavy” atoms (below C in group 14; below N in group 15; below S in group 16) into D–A conjugated polymers allows control over properties through relatively straightforward synthetic chemistry, and produces materials with high molecular weights (>20 000 g mol−1), strong absorption (ε ≈ 40 000 L mol−1 cm−1), narrow highest occupied molecular orbital (HOMO)–lowest unoccupied molecular orbital (LUMO) gaps (<1 eV), as well as high charge‐carrier mobility (>10−2 cm2 V−1 s−1). This Trend article aims to describe heavy‐atom substitution effects in D–A polymers, and their applications, by systematically examining representative polymer structures.

Controlling the phase-separation behavior and achieving an ideal morphology has turned into one of the most important challenges in the field of polymer electronics. In this study we report a straightforward route to ‘blocky’ copolymers that incorporates selenophene into a benzodithiophene (BDT)–thienothiophene (TT) donor–acceptor system for improved molecular ordering. The blocky structure preserves the optical properties of the parent polymers, which is different than an analogue employing purely statistical sequence. Peak force quantitative nanomechanical mode atomic force microscopy reveals a more ordered network-like morphology in blocky polymer:PC71BM films. However the photovoltaic properties of blocky polymers are still lower than the physical mixtures of the two parent polymers. This blocky copolymer approach can be applied to many other polymerization methods to prepare many new types of blocky D–A polymers. As such, it could be a new tool for tuning the polymer crystallinity, and eventually achieving controllable solid-state morphology for polymer electronic applications.

13C hyperfine coupling constants of the MuC60 radical have been measured by muon level-crossing spectroscopy, using a dilute solution of 99% enriched 13C60 in decalin. The signs as well as the magnitudes of the hyperfine constants were determined. The results range from 52.6 to −25.4 MHz and support those calculations which predict an extended distribution of unpaired electron spin density in radical adducts of fullerenes. The hyperfine constants are consistent with published electron spin resonance results for (CD3)3CC60, but contradict a recent report for HC60, where a considerably smaller value is reported for the largest splitting. [ABSTRACT FROM AUTHOR]

Amphibolite facies metasedimentary schists within the Yukon-Tanana terrane in the northern Canadian Cordillera reveal a two-stage, polymetamorphic garnet growth history. In situ U-Th-Pb Sensitive High Resolution Ion Microprobe dating of monazite provide timing constraints for the late stages of garnet growth, deformation and subsequent decompression. Distinct textural and chemical growth zoning domains, separated by a large chemical discontinuity, reveal two stages of garnet growth characterized in part by: (i) a syn-kinematic, inclusion-rich stage-1 garnet core; and (ii) an inclusion-poor, stage-2 garnet rim that crystallized with syn- to post-kinematic staurolite and kyanite. Phase equilibria modelling of garnet molar and compositional isopleths suggest stage-1 garnet growth initiated at ~600 °C, 8 kbar along a clockwise P-T path. Growth of the compositionally distinct, grossular-rich, pyrope-poor inner portion of the stage-2 overgrowth is interpreted to have initiated at higher pressure and/or lower temperature than the stage-1 core along a separate P-T loop, culminating at peak P-T conditions of ~650-680 °C and 9 kbar. Stage-2 metamorphism and the waning development of a composite transposition foliation ( ST) are dated at c. 118 Ma from monazite aligned parallel to ST, and inclusions in syn- to post- ST staurolite and kyanite. Slightly younger ages ( c. 112 Ma) are obtained from Y-rich monazite that occurs within resorbed areas of both stage-1 and stage-2 garnet, together with retrograde staurolite and plagioclase. The younger ages obtained from these texturally and chemically distinct grains are interpreted, with the aid of phase equilibria calculations, to date the growth of monazite from the breakdown of garnet during decompression at c. 112 Ma. Evidence for continued near-isothermal decompression is provided by the presence of retrograde sillimanite, and cordierite after staurolite, which indicates decompression below ~4-5 kbar prior to cooling below ~550 °C. As most other parts of the Yukon-Tanana terrane were exhumed to upper crustal levels in the Early Jurassic, these data suggest this domain represents a tectonic window revealing a much younger, high-grade tectono-metamorphic core (infrastructure) within the northern Cordilleran orogen. This window may be akin to extensional core complexes identified in east-central Alaska and in the southeastern Canadian Cordillera. [ABSTRACT FROM AUTHOR]

Sierra Negra volcano, the most voluminous shield volcano in the Galápagos archipelago and one of the largest basaltic calderas in the world, erupted on October 22, 2005 after more than 25years of quiescence. GPS and satellite radar interferometry (InSAR) monitoring of the deformation of the caldera floor in the months prior to the eruption documented extraordinary inflation rates (1cm/day). The total amount of uplift recorded since monitoring began in 1992 approached 5m at the center of the caldera over the eight days of the eruption the caldera floor deflated a maximum of 5 m and subsquently renewed its inflation, but at a decelerating rate. To gain insight into the nature of the subsurface mass/density changes associated with the deformation, gravity measurements performed in 2005, 2006, and 2007 are compared to previous measurements from 2001-2002 when the volcano underwent a period of minor deflation and magma withdrawal. The residual gravity decrease between 2001-2002 and 2005 is among the largest ever recorded at an active volcano (−950 μGal) and suggests that inflation was accompanied by a relative density decrease in the magmatic system. Forward modeling of the residual gravity data in 4D (from 2002 to 2005) gives an estimate of the amount of vesiculation in the shallow sill required to explain the observed gravity variations. Geochemical constraints from melt inclusion and satellite remote-sensing data allow us to estimate the pre-eruptive gas content of the magma and place constraints on the thickness of the gas-rich sill necessary to produce the gravity anomalies observed. Results suggest that reasonable sill thicknesses (700–800m) and bubble contents (10–50 volume %) can explain the large decrease in residual gravity prior to eruption. Following the eruption (2006 and 2007), the deformation and gravity patterns suggest re-equilibration of the pressure regime in the shallow magma system via a renewed influx of relatively gas-poor magma into the shallow parts of the system.