Larger Bodies Research Articles

Condition, not eyespan, predicts contest outcome in female stalk-eyed flies, Teleopsis dalmanni.

In contests among males, body condition is often the key determinant of a successful outcome, with fighting ability signaled by so-called armaments, that is, exaggerated, condition-dependent traits. However, it is not known whether condition and exaggerated traits function in the same way in females. Here, we manipulated adult condition by varying larval nutrition in the stalk-eyed fly, Teleopsis dalmanni, a species in which eyespan is exaggerated in both sexes, and we measured the outcome of contests between females of similar or different body condition and relative eyespan. We found that females in higher condition, with both larger bodies and eyespan, won a higher proportion of encounters when competing against rivals of lower condition. However, when females were of equal condition, neither eyespan nor body length had an effect on the outcome of a contest. An analysis of previously published data revealed a similar pattern in males: individuals with large relative eyespan did not win significantly more encounters when competing with individuals of a similar body size. Contrary to expectations, and to previous findings in males, there was no clear effect of differences in body size or eyespan affecting contest duration in females. Taken together, our findings suggest that although eyespan can provide an honest indicator of condition, large eyespans provide no additional benefit to either sex in intrasexual aggressive encounters; body size is instead the most important factor.

The Baptist Colleges in the Mid-Nineteenth Century

The era between the 1830s and the opening of the 1860s witnessed a gradual shift in Baptist ministerial education. Nonconformists were becoming more respectable; and educational standards were rising in society at large. There was therefore a tendency for an academy to turn into a college. A change of scale meant that several institutions grew into larger bodies. The setting often altered from basic provision to grand facilities. The instruction delivered generally ceased to be amateurish and became more professional. The purpose shifted further from evangelism to study. Standards rose from the elementary to the advanced. The range of studies tended to move from a narrower to a broader variety. And the theology shifted from a confessional to an evangelical stance. Although there was resistance to the trends, especially from C. H. Spurgeon, traditional academies were becoming colleges with a newer ethos.

Whitesel, J. Fat Gay Men: Girth, Mirth, and the Politics of Stigma, New York: New York University Press. 2014. 192pp. £13.99 ISBN 978–0814724125

For many years, the debate whether ‘fat is a feminist issue' has been, understandably, at the heart of the discipline of fat studies. Yet recently there have been monographs by scholars such as Lee Monaghan and Sander Gilman that have been devoted to the consideration of masculinity and fat. Whitesel's research monograph now broadens these debates to address the issue faced by men who identify both as fat and gay. To identify as fat in contemporary Western culture is extremely difficult when nearly all media and cultural discourses exalt thinness and gym-toned muscularity. Fat prejudice (if not even fat phobia) continues to be a problem in many cultural and social settings despite advancements in fat acceptance politics. However, in the body fascist ‘no pecs; no sex’ world of metropolitan gay masculinity it is, arguably, even more challenging to identify as fat. Whitesel emphasises that fat gay men face a double exclusion – first from heteronormative culture and then, because of their size, exclusion from within gay culture itself. As such, fat gay men are ‘a subaltern within the subaltern’ (p. 2). Attempting to challenge these prejudices are a number of support and social groups in metropolitan gay culture and Whitesel's ethnographic study, drawing upon interviews and in-depth field notes, analyses the politics of one such group: Girth & Mirth. Whitesel's highly accessible book begins with an overview of the history of Girth & Mirth and shows how this organisation functions as both a social club and support network for fat gay men. The second chapter examines the bullying that fat gay men often experience and chapters 3 and 4 then consider how Girth & Mirth events attempt to challenge and subvert the strategies of oppression that these men may have suffered. Whitesel engages in detailed analyses of the events that Girth & Mirth organise, including the Super Weekend in which fat gay men redefine themselves as sex objects rather than abject bodies of derision, and Convergence, which aims to challenge issues of class stereotyping usually associated with larger bodies. The final chapter addresses an important issue within queer studies: shame. Can fat gay men address the stigma of fat through strategies of carnivalesque and camp and what do these strategies do to a body's sexualised identification? Fat Gay Men is one of the first sustained studies of the politics of fat, gay male embodiment in metropolitan Western culture. Although it is an academic monograph, Whitesel's accessible, lively writing style – and command of the critical material – would also make it an excellent text for undergraduate teaching. Each chapter is underpinned by relevant cultural theory but never falls into the trap of recycling academic jargon. Throughout every chapter it is evident that the analyses are never simply abstract theories but are informed by the lived experience of larger gay men. One slight disappointment is that the reader may have appreciated some comparative analysis to consider the differences and similarities between fat, gay men and their heterosexual (male and female) counterparts, but the book stops a little short of doing this. However, a consideration of Western fatness is not the book's remit and instead Fat Gay Men should be appreciated for its detailed and nuanced investigation into subcultural identifications and performances, which may well be unfamiliar issues to many scholars. Even queer-identifying readers may not have been aware of the political efforts that fat gay men need to make in their fight for equality within gay culture itself. The struggle fat gay men may face in order to identify not only in terms of sexual desirability but simply for the right not to apologise for being oversized is brought to the foreground of the debate in every chapter. Whitesel's own emotional investment in the politics of this group is extremely engaging and infectious and so all readers, whether gay, straight, fat or thin, should feel they are not simply reading about the subcultural activities organised by Girth & Mirth but instead recognise and relate to this narrative of struggle on the road to acceptance.

POLARIMETRY WITH THE GEMINI PLANET IMAGER: METHODS, PERFORMANCE AT FIRST LIGHT, AND THE CIRCUMSTELLAR RING AROUND HR 4796A

We present the first results from the polarimetry mode of the Gemini Planet Imager (GPI), which uses a new integral field polarimetry architecture to provide high contrast linear polarimetry with minimal systematic biases between the orthogonal polarizations. We describe the design, data reduction methods, and performance of polarimetry with GPI. Point spread function subtraction via differential polarimetry suppresses unpolarized starlight by a factor of over 100, and provides sensitivity to circumstellar dust reaching the photon noise limit for these observations. In the case of the circumstellar disk around HR 4796A, GPI's advanced adaptive optics system reveals the disk clearly even prior to PSF subtraction. In polarized light, the disk is seen all the way in to its semi-minor axis for the first time. The disk exhibits surprisingly strong asymmetry in polarized intensity, with the west side >9 times brighter than the east side despite the fact that the east side is slightly brighter in total intensity. Based on a synthesis of the total and polarized intensities, we now believe that the west side is closer to us, contrary to most prior interpretations. Forward scattering by relatively large silicate dust particles leads to the strong polarized intensity on the west side, and the ring must be slightly optically thick in order to explain the lower brightness in total intensity there. These findings suggest that the ring is geometrically narrow and dynamically cold, perhaps shepherded by larger bodies in the same manner as Saturn's F ring.

Spatial Multiplexing

Geometrical constraints limit how much information can be received and emitted along real pathways across the boundary of any processor. Applied to central nervous systems this imposes a seemingly impassable bottleneck to the evolution of large brains. A small brain could never access enough information to warrant a larger brain. A small brain could not send enough information to operate a large body. Larger bodies are needed to support larger brains. Thus, with a rare exception, there are no invertebrates with large brains or large bodies. It is proposed that a convergent-divergent scanning neural network developed which enabled vertebrates to squeeze more information through this bottleneck by “spatial multiplexing”. This reduces the number of pathways into, between and from processors by a factor of 16 while maintaining spatial and intensity accuracy. This paper describes spatial multiplexing using downloadable spreadsheet models and shows how the necessity of scanning likely introduced brain rhythms.

The Precambrian history of the origin and evolution of the Solar System and Earth. Part 1

The paper provides a review of early stages of development the Solar System and the geological history of Earth with reference to the latest data on the origin of the Solar System and the formation of the first continental rocks and results of studies of zircon, the oldest mineral so far dated on Earth. The formation of the Solar System from a gas-and-dust nebula is estimated to have begun 4.568 billion years ago. Ice was formed 1.5 million years later; it concentrated at the periphery of the system and served as the material for the largest planets, Jupiter and Saturn. In the central areas of the system, asteroids with diameters of about 10 km were formed. Their small bodies were composed of the basic material of the solar nebula, as evidenced by carbonaceous chondrite, CI, which composition is similar to the composition of the Sun, with the exception of hydrogen, helium, and volatile components that served as the main material for peripheral planets of the Solar System. Due to collision and partial merger of such small bodies, the formation of embryos of the terrestrial planets was initiated. Gravity made such embryos to cluster into larger bodies. After 7 million years, large asteroids and planet Mars were formed. It took 11 million years to form Planet Earth with a mass of 63 %, and 30 million years to form 93 % of its mass. Almost from the beginning of the formation of the Earth, short-lived radionuclides, 26Al and 60Fe, caused warming up of the small planetary bodies which led to the formation of their cores. During the initial stages, small magma reservoirs were formed, and molten iron particles gathered in the centres of the planetary bodies. As suggested by the ratio of 182W/184W, the major part of the core was formed within 20 million years, while its full mass accumulated completely within the next 50 million years. In 30–40 million years after the creation of the Solar System, the Earth collided with a cosmic body which mass was close to the mass of Mars, and it was the beginning of the formation of its satellite, Moon. When the Earth – Moon system was subject to the major meteorite bombardment 4.5–4.1 billion years ago, zircons formed due to impact activity on the Moon, and on Earth it caused major eruption of basaltic magma, the differentiation of which led to the formation of acid magmas in small amounts which caused the formation of zircons, the only remnants of the first continental rocks of Earth. Later on, meteorite bombardment continued and contributed to the burial of the first continental acid and basic rocks in the mantle, wherein such rocks eventually became part of the mantle which became the progenitor of granite-greenstone rock associations. Grey gneisses contain traces of the first continental formations of Earth as evidenced by ancient zircons that are ubiquitous in the crust of Earth. The above is confirmed by results of detailed studies of regional zircons with the use of modern analytical equipment providing for high accuracy of local analyses.

Climatic correlates of body size in European tenebrionid beetles (Coleoptera: Tenebrionidae)

Tenebrionidae are one of the largest families of beetles and are known for their adaptations to hot and dry climates. An increase in body size also increases the volume/surface area ratio, which reduces transpiration, and hence water loss. If an increase in body size is an important adaptation in tenebrionids to cope with increasing aridity, we expect a correlation between body size and climatic gradients in the major tenebrionid clades. Alternatively, we can postulate that arid climates do not drive body size evolution, but rather select, from a wider fauna containing species of any size, those that have larger bodies. In this case we expect that drier regions will host faunas that contain, on average, larger species. To test the first hypothesis, we correlated inter-specific body size variation in the main tenebrionid clades with climatic gradients in Europe. We found only weak trends. To test the second hypothesis, we regressed mean body size of European country faunas against climatic characteristics. We found a strong increase in body size in southern faunas experiencing hot and dry climates. Therefore, increase in body size is not a major adaptation in tenebrionid evolution, but climate is an important filtering factor that determines a prevalence of larger species in southern Europe.

Anomopterellidae Restored, with Two New Genera and Its Phylogeny in Evanioidea (Hymenoptera)

BackgroundAnomopterellidae was originally classified as a family within the Evanioidea, and later lowered to a subfamily, Anomopterellinae, of Praeaulacidae. Up to date, only Rasnitsyn 1975, with four species, was assigned to Anomopterellinae. Due to their special wing venation and their metasomal attachment similar to those known in Evanioidea, the systematic position of Anomopterellinae in Evanioidea has been in contention.Principal FindingsHere we report a new fossil genus Synaphopterella gen. nov. and six species from the Middle Jurassic of China and transfer Anomopterella stenocera Rasnitsyn, 1975, from Upper Jurassic of Kazakhstan, to Choristopterella gen. nov. We place these three genera in the restored family Anomopterellidae and provide a key to known genera and species.Conclusions/SignificanceBased on new fossil specimens and phylogenetic analyses, Praeaulacidae has the most basal position in Evanioidea and it is justifiable to restore Anomopterellidae Rasnitsyn, 1975 as a full family. Comparing the size of all described anomopterellids from China, Mongolia and Kazakhstan, we conclude that the species from China have larger bodies and forewings. Diversity of the Praeaulacidae and Anomopterellidae in the late Middle Jurassic of Daohugou suggests that Evanioidea appeared at least before the late Middle Jurassic.

Ontogenetic and sexual differences of thermal biology and locomotor performance in a lacertid lizard, Eremias multiocellata

A viviparous lizard, Eremias multiocellata, was used to investigate the possible sexual and ontogenetic effects on selected body temperature, thermal tolerance range and the thermal dependence of locomotor performance. We show that adults are sexually dimorphic and males have larger bodies and heads than females. Adults selected higher body temperatures (34.5 vs. 32.4°C) and could tolerate a broader range of body temperatures (8.1–46.8 vs. 9.1–43.1°C) than juveniles. The sprint speed and maximum sprint distance increased with temperature from 21°C to 33°C, but decreased at 36°C and 39°C in both juveniles and adults. Adults ran faster and longer than juveniles at each tested temperature. Adult locomotor performance was not correlated with snout–vent length (SVL) or sex, and sprint speed was positively correlated with hindlimb length. Juvenile locomotor performance was positively correlated with both SVL and hindlimb length. The ontogenetic variation in selected body temperature, thermal tolerance and locomotor performance in E. multiocellata suggests that the effects of morphology on temperature selection and locomotor performance vary at different ontogenetic stages.

THE FATE OF PLANETESIMALS IN TURBULENT DISKS WITH DEAD ZONES. I. THE TURBULENT STIRRING RECIPE

Turbulence in protoplanetary disks affects planet formation in many ways. While small dust particles are mainly affected by the aerodynamical coupling with turbulent gas velocity fields, planetesimals and larger bodies are more affected by gravitational interaction with gas density fluctuations. For the latter process, a number of numerical simulations have been performed in recent years, but a fully parameter-independent understanding has not been yet established. In this study, we present simple scaling relations for the planetesimal stirring rate in turbulence driven by magnetorotational instability (MRI), taking into account the stabilization of MRI due to Ohmic resistivity. We begin with order-of-magnitude estimates of the turbulence-induced gravitational force acting on solid bodies and associated diffusion coefficients for their orbital elements. We then test the predicted scaling relations using the results of recent Ohmic-resistive MHD simulations by Gressel et al. We find that these relations successfully explain the simulation results if we properly fix order-of-unity uncertainties within the estimates. We also update the saturation predictor for the density fluctuation amplitude in MRI-driven turbulence originally proposed by Okuzumi & Hirose. Combination of the scaling relations and saturation predictor allows to know how the turbulent stirring rate of planetesimals depends on disk parameters such as the gas column density, distance from the central star, vertical resistivity distribution, and net vertical magnetic flux. In Paper II, we apply our recipe to planetesimal accretion to discuss its viability in turbulent disks.

Pollinator shift to managed honeybees enhances reproductive output in a bumblebee-pollinated plant

Introduced honeybees have had a large impact on native ecosystems by disrupting native plant–pollinator interactions. However, little is known of the effect of honeybees on reproduction of bumblebee-pollinated plants. Seasonal displacement of native bumblebees by introduced honeybees (Apis mellifera and A. cerana) was observed in Pedicularis densispica, endemic to Hengduan Mountains, China, providing an opportunity for honeybee presence/absence comparisons. Five-year field surveys were conducted in one frequently disturbed population at Yila Pasture (YP). We compared pollination effectiveness (combinations of visitation rate, efficiency in pollen transfer, and potential geitonogamy) between native and introduced managed bees. The total visitation rate of native bees and subsequent reproductive output decreased progressively, but honeybee introduction resulted in at least twofold increase in visitation and 70 % increase in seed set. In general, native bumblebees, which have larger bodies and longer proboscises and spent more time probing single flowers, were more efficient than honeybees in terms of pollen removal and pollen deposition during first visits to virgin flowers. Compared with bumblebees, honeybees visited markedly fewer flowers in sequence within individual plants, potentially reducing geitonogamous pollination. Our data highlight that introduced honeybees can provide pollination service in terms of both quantity and quality for P. densispica. We suggest honeybee introduction as an effective way to augment pollination of P. densispica at disturbed and isolated sites.

An Ancient Core Dynamo in Asteroid Vesta

The asteroid Vesta is the smallest known planetary body that has experienced large-scale igneous differentiation. However, it has been previously uncertain whether Vesta and similarly sized planetesimals formed advecting metallic cores and dynamo magnetic fields. Here we show that remanent magnetization in the eucrite meteorite Allan Hills A81001 formed during cooling on Vesta 3.69 billion years ago in a surface magnetic field of at least 2 microteslas. This field most likely originated from crustal remanence produced by an earlier dynamo, suggesting that Vesta formed an advecting liquid metallic core. Furthermore, the inferred present-day crustal fields can account for the lack of solar wind ion-generated space weathering effects on Vesta.

Heidegger, Merleau-Ponty and the Question of Biological Continuism

I THE LEGACY OF HUMAN EXCEPTIONALISM AND MERLEAUPONTY'S TURN TO EVOLUTIONARY BIOLOGY Even as posthumanists seek to dismantle the legacy of human exceptionalism, a queasy reluctance among philosophers prevents full acknowledgement of our kinship with the rest of animalia. Heidegger's declaration that animals are 'poor in world' and his description of an abyss yawning between humans and all other animals established the best known and most influential position in this regard. (1) Even though Derrida challenged what he saw as Heidegger's dogmatic humanism and violent commentary on animals, (2) he could not acknowledge the biological continuism which evolutionary science, genomics, and microbiology make obvious. (3) Matthew Calarco takes 'Derrida's insistence on maintaining the human-animal distinction to be one of the most dogmatic and puzzling moments in all of his writings' (4) and wonders 'why he would use this language of ruptures and abysses when the largest bodies of empirical knowledge we have concerning human beings and animals strongly contest such language'. (5) Similar to Derrida, Giorgio Agamben decries what he calls 'the anthropological machine' but never moves beyond it. He urges us to work on the divisions of animal from human and suggests that 'even the most luminous sphere of our relations with the divine depends, in some way, on that darker one which separates us from the animal'. (6) Only Cary Wolfe, Matthew Calarco, Donna Haraway, and Kelly Oliver among prominent recent animal theorists are moving away from abyssal distinctions between humans and other animals, Haraway the most decisively. (7) Yet more than fifty years ago, Maurice Merleau-Ponty had already gone far beyond Heidegger to seriously explore the philosophical consequences of evolutionary biology and ethology--the scientific studies of actual animals--and to anticipate the radical breakthroughs of the past several decades in studies of animal sentience, tool use, communication, and culture. Merleau-Ponty laid the theoretical groundwork for an understanding of human animality that is congruent with evolutionary biology and ethology. (8) In this essay I will briefly describe Heidegger's resistance to thinking of humans as animals within an evolutionary perspective, in order to demonstrate how Merleau-Ponty took a radically different direction through a thoughtful engagement with evolutionary science and ethology that affirms both biological continuity and the distinctive qualities of our species. At stake in these debates is the question of whether cultural theory can accept the legitimacy of modern science as an access to knowledge about the natural world, or whether we are trapped in a solipsistic bubble. Calarco thinks that persistent anthropocentrism is one of the chief blind spots in contemporary Continental philosophy, claiming that it is always 'one version or another of the human that falsely occupies the space of the universal and that functions to exclude what is considered nonhuman (which, of course, includes the immense majority of human beings themselves, along with all else deemed to be nonhuman) from ethical and political consideration'. (9) And as Derrida argued in his Geschlecht essays and also in The Animal That Therefore I Am, a central problem remains the failure of theorists to seriously pay attention to the life sciences, particularly the experimental studies of other animals. (10) He himself never got around to doing this, and neither have most participants in recent critical animal studies debates indebted to Derrida's work. (11) What makes Merleau-Ponty's philosophy unique and radical in this regard is his lifelong engagement with the sciences of his own era, including Gestalt psychology and cognitive neuroscience for his work on embodiment in The Phenomenology of Perception, and in his later writings, quantum mechanics, evolutionary biology, embryology, and ethology. Close examination of empirical animal research in his late Nature lectures led to the beginnings of an understanding of a 'strange kinship' between humans and animals over evolutionary time, and the human-animality intertwining that defines our species' distinctive way of participating in the Brute being of the world's flesh. …

Pitted Terrain on Vesta and Implications for the Presence of Volatiles

We investigated the origin of unusual pitted terrain on asteroid Vesta, revealed in images from the Dawn spacecraft. Pitted terrain is characterized by irregular rimless depressions found in and around several impact craters, with a distinct morphology not observed on other airless bodies. Similar terrain is associated with numerous martian craters, where pits are thought to form through degassing of volatile-bearing material heated by the impact. Pitted terrain on Vesta may have formed in a similar manner, which indicates that portions of the surface contain a relatively large volatile component. Exogenic materials, such as water-rich carbonaceous chondrites, may be the source of volatiles, suggesting that impactor materials are preserved locally in relatively high abundance on Vesta and that impactor composition has played an important role in shaping the asteroid's geology.

Elemental Mapping by Dawn Reveals Exogenic H in Vesta’s Regolith

Using Dawn's Gamma Ray and Neutron Detector, we tested models of Vesta's evolution based on studies of howardite, eucrite, and diogenite (HED) meteorites. Global Fe/O and Fe/Si ratios are consistent with HED compositions. Neutron measurements confirm that a thick, diogenitic lower crust is exposed in the Rheasilvia basin, which is consistent with global magmatic differentiation. Vesta's regolith contains substantial amounts of hydrogen. The highest hydrogen concentrations coincide with older, low-albedo regions near the equator, where water ice is unstable. The young, Rheasilvia basin contains the lowest concentrations. These observations are consistent with gradual accumulation of hydrogen by infall of carbonaceous chondrites--observed as clasts in some howardites--and subsequent removal or burial of this material by large impacts.

DISK MASSES AT THE END OF THE MAIN ACCRETION PHASE: CARMA OBSERVATIONS AND MULTI-WAVELENGTH MODELING OF CLASS I PROTOSTARS

We present imaging observations at 1.3 mm wavelength of Class I protostars in the Taurus star forming region, obtained with the CARMA interferometer. Of an initial sample of 10 objects, we detected and imaged millimeter wavelength emission from 9. One of the 9 is resolved into two sources, and detailed analysis of this binary protostellar system is deferred to a future paper. For the remaining 8 objects, we use the CARMA data to determine the basic morphology of the millimeter emission. Combining the millimeter data with 0.9 micron images of scattered light, Spitzer IRS spectra, and broadband SEDs (all from the literature), we attempt to determine the structure of the circumstellar material. We consider models including both circumstellar disks and envelopes, and constrain the masses (and other structural parameters) of each of these components. We show that the disk masses in our sample span a range from <0.01 to >0.1 Msun. The disk masses for our sample are significantly higher than for samples of more evolved Class II objects. Thus, Class I disk masses probably provide a more accurate estimate of the initial mass budget for star and planet formation. However, the disk masses determined here are lower than required by theories of giant planet formation. The masses also appear too low for gravitational instability, which could lead to high mass accretion rates. Even in these Class I disks, substantial particle growth may have hidden much of the disk mass in hard-to-see larger bodies.

Planetesimal formation by sweep-up: how the bouncing barrier can be beneficial to growth

The formation of planetesimals is often accredited to collisional sticking of dust grains. The exact process is unknown, as collisions between larger aggregates tend to lead to fragmentation or bouncing rather than sticking. Recent laboratory experiments have however made great progress in the understanding and mapping of the complex physics involved in dust collisions. We want to study the possibility of planetesimal formation using the results from the latest laboratory experiments, particularly by including the fragmentation with mass transfer effect, which might lead to growth even at high impact velocities. We present a new experimentally and physically motivated dust collision model capable of predicting the outcome of a collision between two particles of arbitrary masses and velocities. It is used together with a continuum dust-size evolution code that is both fast in terms of execution time and able to resolve the dust well at all sizes, allowing for all types of interactions to be studied without biases. We find that for the general dust population, bouncing collisions prevent the growth above millimeter-sizes. However, if a small number of cm-sized particles are introduced, for example due to vertical mixing or radial drift, they can act as a catalyst and start to sweep up the smaller particles. At a distance of 3 AU, 100-meter-sized bodies are formed on a timescale of 1 Myr. We conclude that direct growth of planetesimals might be a possibility thanks to a combination of the existence of a bouncing barrier and the fragmentation with mass transfer effect. The bouncing barrier is here even beneficial, as it prevents the growth of too many large particles that would otherwise only fragment among each other, and creates a reservoir of small particles that can be swept up by larger bodies. However, for this process to work, a few seeds of cm in size or larger have to be introduced.

Self-Enhancement Following Exposure to Idealized Body Portrayals in Ethnically Diverse Men: A Fantasy Effect of Advertising

Viewing idealized body portrayals of men and women in advertising is known to have negative effects on men’s self-esteem and body dissatisfaction, but little research investigates these effects across race/ethnicity. Racial minorities tend to idealize larger bodies than Whites and so might respond differently to advertising influences. We investigated whether exposure to idealized portrayals of male and female bodies in TV advertisements has different effects on men of different race/ethnicity. Additionally, we investigated whether implicit methods reveal different results than self-reports. One hundred and sixty Asian, Hispanic, and White American male undergraduates from a university in California (USA) were randomly assigned to watch TV advertisements portraying thin women, muscular men, or watched no ads. Their implicit self-esteem was measured using the Implicit Association Test, and a questionnaire assessed explicit self-esteem, actual-ideal body discrepancy, and perception of weight-related health-risks. Exposure to portrayals of muscular men decreased actual-ideal body discrepancy in all men. Exposure to portrayals of thin women increased men’s implicit but not explicit self-esteem in Asian and Hispanic men only. Both these findings are consistent with a self-enhancing role of exposure to idealized male and female bodies in advertising, which is often referred to as a “fantasy effect”. This study provides evidence that media exposure interacts with culturally local body ideals and so can produce varying effects in different racial/ethnic groups. This result could have important implications for interventions.

TIDAL DISSIPATION COMPARED TO SEISMIC DISSIPATION: IN SMALL BODIES, EARTHS, AND SUPER-EARTHS

While the seismic quality factor and phase lag are defined solely by the bulk properties of the mantle, their tidal counterparts are determined both by the bulk properties and self-gravitation of a body as a whole. For a qualitative estimate, we model the body with a homogeneous sphere and express the tidal phase lag through the lag in a sample of material. Although simplistic, our model is sufficient to understand that the lags are not identical. The difference emerges because self-gravitation pulls the tidal bulge down. At low frequencies, this reduces strain and makes tidal damping less efficient in larger bodies. At high frequencies, competition between self-gravitation and rheology becomes more complex, though for sufficiently large superearths the same rule works: the larger the body, the weaker tidal damping in it. Being negligible for small terrestrial planets and moons, the difference between the seismic and tidal lagging (and likewise between the seismic and tidal damping) becomes very considerable for superearths. In those, it is much lower than what one might expect from using a seismic quality factor. The tidal damping rate deviates from the seismic damping rate especially in the zero-frequency limit, and this difference takes place for bodies of any size. So the equal in magnitude but opposite in sign tidal torques, exerted on one another by the primary and the secondary, go smoothly through zero as the secondary crosses the synchronous orbit. We describe the mantle rheology with the Andrade model, allowing it to lean towards the Maxwell model at the lowest frequencies. To implement this additional flexibility, we reformulate the Andrade model by endowing it with a free parameter which is the ratio of the anelastic timescale to the viscoelastic Maxwell time of the mantle. Some uncertainty in this parameter's frequency-dependence does not influence our principal conclusions.

A MECHANISM TO PRODUCE THE SMALL DUST OBSERVED IN PROTOPLANETARY DISKS

Small (sub)-micron dust is present over the entire lifetime of protoplanetary disks. As aggregation readily depletes small particles, one explanation might be that dust is continuously generated by larger bodies in the midplane and transported to the surface of the disks. In general, in a first step of this scenario, the larger bodies have to be destroyed again and different mechanisms exist with the potential to accomplish this. Possible destructive mechanisms are fragmentation in collisions, erosion by gas drag or light induced erosion. In laboratory experiments we find that the latter, light induced erosion by Knudsen compression and photophoresis, can provide small particles. It might be a preferred candidate as the dust is released into a low particle density region. The working principle of this mechanism prevents or decreases the likelihood for instant re-accretion or re-growth of large dense aggregates. Provided that there is a particle lift, e.g. turbulence, these particles might readily reach the surface of the disk.