215 research outputs found
Facial visualizations of women’s voices suggest a cross-modality preference for femininity
Women with higher-pitched voices and more feminine facial features are commonly judged as being more attractive than are women with lower-pitched voices and less feminine faces, possibly because both features are affected by (age-related) variations in endocrine status. These results are primarily derived from investigations of perceptions of variations in single-modality stimuli (i.e., faces or voices) in samples of young adult women. In the present study we sought to test whether male and female perceptions of women’s voices affect visual representations of facial femininity. Eighty men and women judged voice recordings of 10 young girls (11-15 years), 10 adult women (19-28 years) and 10 peri-/post-menopausal women (50-64 years) on age, attractiveness, and femininity.
Another 80 men and women were asked to indicate the face they think each voice corresponded to using a video that gradually changed from a masculine looking male face into a feminine looking female face. Both male and female participants perceived voices of young girls and adult women to be significantly younger, more attractive and feminine than those of peri-/post-menopausal women. Hearing young girls’ and adult women’s voices resulted in both men and women selecting faces that differed markedly in apparent femininity from those associated with peri-/post-menopausal women’s voices. Voices of young girls had the strongest effect on visualizations of facial femininity. Our results suggest a cross-modal preference for women’s vocal and facial femininity, which depends on female age and is independent of the perceiver’s sex
Friendly societies in the rural East Riding, 1830-1912
Local and affiliated order friendly societies which together formed the largest working-class movement in Victorian Britain have been largely ignored by social and labour historians. Oddfellows, Foresters, Druids, Shepherds and Gardeners with their ritual, regalia, and secrecy imitative of Freemasonry, emerged as benefit societies in industrial Yorkshire and Lancashire in the second and third decades of the nineteenth century. The orders exploded into the East Riding in the wake of the passing of the New Poor Law in 1834 and its implementation three years later but many branches suffered severe set-backs or extinction during the economic crisis which hit agriculture in 1848-52. A substantial number of those that survived, many of them well into the twentieth century, chose independence rather than the authoritarian rule of a national headquarters.Affiliated branches far from being the preserve of the urban artisan, as has been often suggested, had an extensive agricultural worker membership. The founders and leaders of branches, which were most commonly located in larger open settlements with a substantial nonconformist and artisan population, were drawn from all sections of the membership but village craftsmen predominated. The club anniversary which became the principal feast day for many villages was initially, along with public house meetings and funeral ritual, much criticised by Anglican clergy. They found, however, that their annual sermon and attendance at the dinner gave them their principal point of contact with the rural working-class, a fact also realised after 1885 by politicians. The sickness and funeral benefits provided by the orders were considerable in relation to agricultural workers' incomes in the mid-19th century but higher wages and the passing of the National Insurance Act in 1912 considerably decreased their significance to the rural community
Mantle-derived trace element variability in olivines and their melt inclusions
Trace element variability in oceanic basalts is commonly used to constrain the physics of mantle melting and the chemistry of Earth's deep interior. However, the geochemical properties of mantle melts are often overprinted by mixing and crystallisation processes during ascent and storage. Studying primitive melt inclusions offers one solution to this problem, but the fidelity of the melt-inclusion archive to bulk magma chemistry has been repeatedly questioned. To provide a novel check of the melt inclusion record, we present new major and trace element analyses from olivine macrocrysts in the products of two geographically proximal, yet compositionally distinct, primitive eruptions from the Reykjanes Peninsula of Iceland. By combining these macrocryst analyses with new and published melt inclusion analyses we demonstrate that olivines have similar patterns of incompatible trace element (ITE) variability to the inclusions they host, capturing chemical systematics on intra- and inter-eruption scales. ITE variability (element concentrations, ratios, variances and variance ratios) in olivines from the ITE-enriched Stapafell eruption is best accounted for by olivine-dominated fractional crystallisation. In contrast, ITE variability in olivines and inclusions from the ITE-depleted Háleyjabunga eruption cannot be explained by crystallisation alone, and must have originated in the mantle. Compatible trace element (CTE) variability is best described by crystallisation processes in both eruptions. Modest correlations between host and inclusion ITE contents in samples from Háleyjabunga suggest that melt inclusions can be faithful archives of melting and magmatic processes. It also indicates that degrees of ITE enrichment can be estimated from olivines directly when melt inclusion and matrix glass records of geochemical variability are poor or absent. Inter-eruption differences in olivine ITE systematics between Stapafell and Háleyjabunga mirror differences in melt inclusion suites, and confirm that the Stapafell eruption was fed by lower degree melts from greater depths within the melting region than the Háleyjabunga eruption. Although olivine macrocrysts from Stapafell are slightly richer in Ni than those from Háleyjabunga, their overall CTE systematics (e.g., Ni/(Mg/Fe), Fe/Mn and Zn/Fe) are inconsistent with being derived from olivine-free pyroxenites. However, the major element systematics of Icelandic basalts require lithological heterogeneity in their mantle source in the form of Fe-rich and hence fusible domains. We thus conclude that enriched heterogeneities in the Icelandic mantle are composed of modally enriched, yet nonetheless olivine-bearing, lithologies and that olivine CTE contents provide an incomplete record of lithological heterogeneity in the mantle. Modally enriched peridotites may therefore play a more important role in oceanic magma genesis than previously inferred.</p
Clinopyroxene Dissolution Records Rapid Magma Ascent
Magma ascent rates control volcanic eruption styles. However, the rates at which basaltic magmas ascend through the crust remain highly uncertain. Although recent studies have successfully exploited records of decompression driven degassing to estimate the rates at which H2O-rich basalts ascend, such approaches cannot readily be applied to primitive and H2O-poor basalts that erupt in ocean island and mid-ocean ridge settings. Here we present magma ascent rates obtained by modeling the dissolution of clinopyroxene crystals in a wehrlitic nodule from the primitive Borgarhraun lava flow in North Iceland. High-Al2O3 clinopyroxene core compositions are consistent with crystallization near the Moho (~800 MPa), whereas low-Al2O3 clinopyroxene rims and inclusion compositions are consistent with crystallization at or near the surface. We interpret low-Al2O3 rims and inclusions as the crystallized remnants of boundary layers formed by the dissolution of high-Al2O3 clinopyroxene during magma ascent. By combining characteristic rim dissolution lengths of 50–100 μm with published experimental calibrations of clinopyroxene dissolution behavior, we estimate that the Borgarhraun magma most likely decompressed and ascended at rates of 3.0–15 kPa.s−1 and 0.11–0.53 m.s−1, respectively. These rates are slightly faster than published estimates obtained by modeling the diffusive re-equilibration of olivine crystals, suggesting that the Borgarhraun magma either accelerated upwards or that it stalled briefly at depth prior to final ascent. Comparisons with other basaltic eruptions indicate that the H2O-poor magma that fed the dominantly effusive Borgarhraun eruption ascended at a similar rate to some H2O-rich magmas that have fed explosive eruptions in arc settings. Thus, magma ascent rates do not appear to correlate simply with magma H2O contents. Overall, our findings confirm that primitive and H2O-poor basalts can traverse the crust within days, and may erupt with little precursory warning of magma ascent
Dynamic and thermal control of an electromagnetic formation flight testbed
Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 2005.Includes bibliographical references (p. 141).Formation flight of multiple spacecraft is an emerging method for completing complex space missions in an efficient manner. A limitation found in maintaining such formations is the need for precise control at all times. Using traditional thruster propulsion systems can be costly and life-limiting since the propellant is consumed during the mission. An alternative method for providing this relative position control is to use electromagnetic interaction between the vehicles of the formation to provide forces and torques. This method uses electricity alone, which is a renewable resource in space, to provide all actuation to control the formation. The Space Systems Laboratory at MIT is developing this concept with a project called Electromagnetic Formation Flight (EMFF). A two-dimensional testbed has been developed to demonstrate the ability to control vehicle position and attitude using only electromagnetic forces and reaction wheels. A thorough description of this system is given, focusing on the development of its thermal and dynamic control. Innovations to the thermal system, used to cool the superconducting wire of the electromagnet, are described. All systems involved with dynamic control of an EMFF vehicle are identified and the methods used to develop control algorithms are explained. Simulations demonstrating the stability achieved by these controllers are presented and successful experimental results from the testbed are examined. Finally, the test results are used to refine the parameters used in the simulation and a more accurate dynamic model of the system is determined.by Matthew D. Neave.S.M
Geochemical constraints on basalt petrogenesis in the Strait of Sicily Rift Zone (Italy): Insights into the importance of short lengthscale mantle heterogeneity
Igneous activity from the late Miocene to historic time (most recently 1891 CE) in the Strait of Sicily has created
two volcanic islands (Pantelleria and Linosa) and several seamounts. These volcanoes are dominated by transitional
(ol + hy-normative) to alkaline (ne-normative) basaltic lavas and scoriae; volcanic felsic rocks (peralkaline
trachyte-rhyolite) crop out only on Pantelleria. Although most likely erupted through continental crust,
basalts demonstrate no evidence of crustal contamination and are geochemically similar to oceanic island basalts
(OIB). Despite their isotopic similarities, there are considerable compositional differences with respect to major
and trace element geochemistry both between and within the two islands that are due to short-length scale
mantle heterogeneity beneath the region as well as variability in partial melting and magma storage conditions.
Published geophysical surveys suggest that lithospheric thickness beneath both islands is ~60 km; this is consistent
with the results of our geochemical modelling (59\u201360 km), which also suggest mantle potential temperatures
between 1415 and 1435 \ub0C, similar to those documented in other continental passive rifts. Trace
element and isotopic data reveal that the asthenosphere beneath the Strait of Sicily is heterogenous at both interisland
(100s of km) and intra-island (10s of km) scales. Although there is some compositional overlap between
the two major synthems at Linosa, in general the older magmas (Arena Bianca, 700 ka) formed as a result of
~5% partial melting of a depleted MORB mantle (DMM) source enriched with a relatively small amount of
recycled MORB material, whereas the younger magmas (Monte Bandiera, 530 ka) formed as a result of ~2%
partial melting of a similar mantle source. Pantelleria magmas formed from a higher degree (~6%) of partial
melting of a DMM source with a relatively greater amount of recycled MORB material and possibly other
components. Geochemical modelling also suggests the older magmas on Linosa differentiated at a much shallower
level (~8 km) than the younger magmas (~25 km, at or below the base of the crust) prior to eruption.
Magmas stored in higher-level reservoirs were effectively homogenized and preserve a narrower compositional
range than magmas sourced from depth. Data for the seamounts are scarce and compromised by significant
seawater alteration; thus, these volcanic centers cannot be modelled but based on comparative geochemistry
with the islands are likely the result of even smaller (< 2%) degrees of partial melting beneath thicker
(> 60 km) lithosphere. Despite the geophysical similarities between the two islands in terms of lithospheric
thickness and crustal thinning, melt productivity has been greater at Pantelleria, producing a much larger island
and sustaining felsic magmatism, which we hypothesize may ultimately be entirely due to the local occurrence of
much more fusible mantle
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