Stellar Oscillons

We study the weakly nonlinear evolution of acoustic instability of a plane- parallel polytrope with thermal dissipation in the form of Newton's law of cooling. The most unstable horizontal wavenumbers form a band around zero and this permits the development of a nonlinear pattern theory leading to a complex Ginzburg-Landau equation (CGLE). Numerical solutions for a subcritical, quintic CGLE produce vertically oscillating, localized structures that resemble the oscillons observed in recent experiments of vibrated granular material.Comment: 12 Latex pages using aasms4.sty, 2 postscript figures, submitted to the proceedings of the Florida Workshop in Nonlinear Astrophysics and Physic

Is Touch in Romantic Relationships Universally Beneficial for Psychological Well-Being? The Role of Attachment Avoidance.

Affectionate touch is crucial for well-being. However, attachment avoidance is associated with negative attitudes toward touch. We tested two preregistered hypotheses about how attachment avoidance influences the association between touch in romantic couples and psychological well-being. We examined whether greater attachment avoidance is associated with a reduced link between touch and well-being, and/or whether reduced touch mediates the relationship between attachment avoidance and lower well-being. Across three studies, including two dyadic ones, we measured retrospective self-reports (Studies 1 and 2), laboratory observations (Study 2), and daily experiences (Study 3) of touch. Touch and well-being were positively associated, and attachment avoidance was associated with lower well-being and less frequent touch. Touch was associated with greater well-being regardless of level of attachment avoidance, and less frequent touch mediated the negative association between attachment avoidance and well-being in most analyses. This underscores the importance of touch, even for those valuing distance and autonomy

The link between wildlife trade and the global donkey skin product network

Unsustainable global wildlife trade impacts biodiversity and threatens national and global security, but many aspects of this trade remain opaque. Our study is a novel investigation of the alleged links between the trade in wildlife products and in donkey skins. The global donkey skin trade is a newly prevalent and lucrative business, largely driven by Chinese demand for E-Jiao, a traditional medicine derived from donkey skins. Records of donkey skins being seized alongside other wildlife products lead us to hypothesize that there is a link between these two trades. We identified all donkey skin dealers on seven business-to-business e-commerce websites and obtained 14,949 data points. These were used in a network analysis to demonstrate the structure of the network and reveal the connection between the products, including wild animal and plant products offered alongside donkey skins. We identified at least 13 groups of CITES-listed species in the densely connected donkey skin product network, demonstrated an association between the online trade in wildlife products and donkey skins, and discuss the implications of this overlap—including the potential to shed light on potential novel trade pathways in legal and illegal domestic animal and wildlife trade

Conservation inequality and the charismatic cat: Felis felicis

AbstractConservation resources are limited, making it impossible to invest equally in all threatened species. One way to maximise conservation gains is to focus upon those species with particular public appeal, using them to generate funding and support that could also benefit less charismatic species. Although this approach is already used by many conservation organisations, no reliable metrics currently exist to determine the likely charisma of a given species, and therefore identify the most appropriate targets for such campaigns. Here we use market research techniques on over 1500 people from five continents to assess the relative charisma of different mammals, which factors appear to drive it, and how these patterns vary between countries. Felids and primates emerged as highly favoured species for conservation, with the tiger (Panthera tigris) the top species by a wide margin. Using an information theoretic approach we develop models that successfully predict respondents’ preferences across the entire sample, suggesting global commonalities in the attributes that people prefer for conservation. However, by analysing each country separately we are able to improve our models, thus highlighting the importance of identifying locally specific flagships for conservation. The most important attributes were body size and IUCN status, although the extent of baldness, whether the species was a potential threat to humans and whether the eyes were forward or side facing were also widely important. Several of the key attributes revealed in this study could be extrapolated to nearly all terrestrial mammals, paving the way for a standardised global identification of species likely to prove effective for future conservation campaigns. The public preferred species with which they had affinity and familiarity, and we discuss how these aspects could be increased to promote the under-achievers, whilst maximising the funding potential of the highly charismatic mammals. While the felids are widely regarded as a popular taxonomic group, the great extent to which they appealed to our respondents emphasises their potential as ambassadors for conservation. Indeed, the big cats were so highly rated that we might think of them as one, Felis felicis: a globally powerful flagship for conservation

“Trunk-like” heavy ion structures observed by the Van Allen Probes

Dynamic ion spectral features in the inner magnetosphere are the observational signatures of ion acceleration, transport, and loss in the global magnetosphere. We report “trunk-like” ion structures observed by the Van Allen Probes on 2 November 2012. This new type of ion structure looks like an elephant's trunk on an energy-time spectrogram, with the energy of the peak flux decreasing Earthward. The trunks are present in He+ and O+ ions but not in H+. During the event, ion energies in the He+ trunk, located at L = 3.6–2.6, magnetic local time (MLT) = 9.1–10.5, and magnetic latitude (MLAT) = −2.4–0.09°, vary monotonically from 3.5 to 0.04 keV. The values at the two end points of the O+ trunk are energy = 4.5–0.7 keV, L = 3.6–2.5, MLT = 9.1–10.7, and MLAT = −2.4–0.4°. Results from backward ion drift path tracings indicate that the trunks are likely due to (1) a gap in the nightside ion source or (2) greatly enhanced impulsive electric fields associated with elevated geomagnetic activity. Different ion loss lifetimes cause the trunks to differ among ion species

Multi-scale, multivariate community models improve designation of biodiversity hotspots in the Sunda Islands

Species occur in sympatric assemblages, bound together by ecological relationships and interspecific interactions. Borneo and Sumatra host some of the richest assemblages of biota worldwide. The region, however, faces the highest global deforestation rates, which seriously threaten its unique biodiversity. We used a large camera trap dataset that recorded data for 70 terrestrial species of mammals and birds, to explore the drivers of regional species richness patterns. Using a multi-scale, multivariate modelling framework which quantified the main environmental factors associated with patterns of biodiversity, while simultaneously assessing individual relationships of each species, we determined the ecological drivers of sampled biodiversity, and their contributions to community assemblages. We then mapped predicted species richness, evaluated the effectiveness of protected areas in securing biodiversity hotspots, performed gap analysis to highlight biodiverse areas lacking protection and compared our predictions with species richness maps produced by using IUCN range layers. Finally, we investigated the performance of each species as an indicator of sampled biodiversity. We demonstrate that biodiversity in Borneo and Sumatra is primarily affected by gradients of ecological and anthropogenic factors, and only marginally by topographic and spatial factors. In both islands, species are primarily associated with elevational gradients in vegetation and climate, leading to altitudinal zonation in niche separation as a major factor characterizing the islands' biodiversity. Species richness was highest in north-eastern Borneo and in western Sumatra. We found that most predicted biodiversity hotspots are not formally protected in either island; only 9.2 and 18.2% of the modelled species richness occurred within protected areas in Borneo and Sumatra, respectively. We highlighted that our prediction for Borneo performed better than, and differed drastically from, the IUCN species richness layer, while for Sumatra our modelled species richness layer and the IUCN one were similar, and both showed low predictive power. Our analysis suggests that common and generalist carnivores are the most effective indicators of sampled biodiversity and have high potential as focal, umbrella or indicator species to assist multi-species vertebrate conservation planning. Understanding existing drivers and patterns of biodiversity is critical to support the development of effective community conservation strategies in this rapidly changing region

Hopf algebras and Markov chains: Two examples and a theory

The operation of squaring (coproduct followed by product) in a combinatorial Hopf algebra is shown to induce a Markov chain in natural bases. Chains constructed in this way include widely studied methods of card shuffling, a natural "rock-breaking" process, and Markov chains on simplicial complexes. Many of these chains can be explictly diagonalized using the primitive elements of the algebra and the combinatorics of the free Lie algebra. For card shuffling, this gives an explicit description of the eigenvectors. For rock-breaking, an explicit description of the quasi-stationary distribution and sharp rates to absorption follow.Comment: 51 pages, 17 figures. (Typographical errors corrected. Further fixes will only appear on the version on Amy Pang's website, the arXiv version will not be updated.

Differential tumor surveillance by natural killer (NK) and NKT cells

Natural tumor surveillance capabilities of the host were investigated in six different mouse tumor models where endogenous interleukin (IL)-12. does or does not dictate the efficiency of the innate immune response. Gene-targeted and lymphocyte subset-depleted mice were used to establish the relative importance of natural killer (NK) and NK1.1(+) T (NKT) cells in protection from tumor initiation and metastasis. In the models examined, CD3(-) NK cells were responsible for tumor rejection and protection from metastasis in models where control of major histocompatibility complex class I-deficient tumors was independent of IL-12, A protective role for NKT cells was only observed when tumor rejection required endogenous IL-12 activity. In particular, T cell receptor J alpha 281 gene-targeted mice confirmed a critical function for NKT cells in protection from spontaneous tumors initiated by the chemical carcinogen, methylcholanthrene. This is the first description of an antitumor function for NKT cells in the absence of exogenously administered potent stimulators such as IL-12 or alpha-galactosylceramide