Twist and chew: three-dimensional tongue kinematics during chewing in macaque primates

Three-dimensional (3D) tongue movements are central to performance of feeding functions by mammals and other tetrapods, but 3D tongue kinematics during feeding are poorly understood. Tongue kinematics were recorded during grape chewing by macaque primates using biplanar videoradiography. Complex shape changes in the tongue during chewing are dominated by a combination of flexion in the tongue's sagittal planes and roll about its long axis. As hypothesized for humans, in macaques during tongue retraction, the middle (molar region) of the tongue rolls to the chewing (working) side simultaneous with sagittal flexion, while the tongue tip flexes to the other (balancing) side. Twisting and flexion reach their maxima early in the fast close phase of chewing cycles, positioning the food bolus between the approaching teeth prior to the power stroke. Although 3D tongue kinematics undoubtedly vary with food type, the mechanical role of this movement—placing the food bolus on the post-canine teeth for breakdown—is likely to be a powerful constraint on tongue kinematics during this phase of the chewing cycle. The muscular drivers of these movements are likely to include a combination of intrinsic and extrinsic tongue muscles.

Why Men (Don’t) Buy Sex: Purity Moralization and Perceived Harm as Constraints on Prostitution Offending

This study explores the moralization of purity and perceptions of harm as constraints on sex buying among men. Purchasing sex has long been considered an offense against public morality. While personal morality provides a powerful constraint on offending, and people may vary in the extent to which they experience moral intuitions about bodily and spiritual purity, research has so far neglected the role of purity moralization in understanding sex buying behavior. We hypothesize specifically that moral intuitions about purity constrain sex buying by leading people to perceive it as inherently wrong and by eliciting perceptions that sex buying is harmful to prostitutes. We test these hypotheses in a nationally representative survey of U.S. men ( N = 2,525). Results indicate that purity moralization is associated with reduced sex buying, and that this relationship is mediated fully by perceptions of sex buying as harming prostitutes.

simba: the average properties of the circumgalactic medium of 2 ≤ z ≤ 3 quasars are determined primarily by stellar feedback

ABSTRACT We use the simba cosmological hydrodynamic simulation suite to explore the impact of feedback on the circumgalactic medium (CGM) and intergalactic medium (IGM) around 2 ≤ z ≤ 3 quasars. We identify quasars in simba as the most rapidly accreting black holes, and show that they are well matched in bolometric luminosity and correlation strength to real quasars. We extract Lyα absorption in spectra passing at different transverse distances ($10 \, \mathrm{kpc} \lesssim b \lesssim 10 \, \rm Mpc$) around those quasars, and compare to observations of the mean Lyα absorption profile. The observations are well reproduced, except within $100 \, \, \rm kpc$ from the foreground quasar, where simba overproduces absorption; this could potentially be mitigated by including ionization from the quasar itself. By comparing runs with different feedback modules activated, we find that (mechanical) AGN feedback has little impact on the surrounding CGM even around these most highly luminous black holes, while stellar feedback has a significant impact. By further investigating thermodynamic and kinematic properties of CGM gas, we find that stellar feedback, and not AGN feedback, is the primary physical driver in determining the average properties of the CGM around z ∼ 2–3 quasars. We also compare our results with previous works, and find that simba predicts much more absorption within $100 \, \rm kpc$ than the nyx and illustris simulations, showing that the Lyα absorption profile can be a powerful constraint on simulations. Instruments such as VLT-MUSE and upcoming surveys (e.g. WEAVE and DESI) promise to further improve such constraints.

What could we learn about climate sensitivity from variability in the surface temperature record?

<p>We examine what can be learnt about climate sensitivity from variability in the surface air temperature record over the instrumental period, from around 1880 to the present. While many previous studies have used the trend in the time series to constrain equilibrium climate sensitivity, it has recently been argued that temporal variability may also be a powerful constraint. We explore this question in the context of a simple widely used energy balance model of the climate system. We consider two recently-proposed summary measures of variability and also show how the full information content can be optimally used in this idealised scenario. We find that the constraint provided by variability is inherently skewed and its power is inversely related to the sensitivity itself, discriminating most strongly between low sensitivity values and weakening substantially for higher values. As a result of this, is only when the sensitivity is very low that the variability can provide a tight constraint. Our results support the analysis of variability as a potentially useful tool in helping to constrain equilibrium climate sensitivity, but suggest caution in the interpretation of precise results.</p>

Redshift evolution of the Fundamental Plane relation in the IllustrisTNG simulation

ABSTRACT We investigate the Fundamental Plane (FP) evolution of early-type galaxies in the IllustrisTNG-100 simulation (TNG100) from redshift z = 0 to z = 2. We find that a tight plane relation already exists as early as z = 2. Its scatter stays as low as ∼0.08 dex across this redshift range. Both slope parameters b and c (where R ∝ σbIc with R, σ, and I being the typical size, velocity dispersion, and surface brightness) of the plane evolve mildly since z = 2, roughly consistent with observations. The FP residual $\rm Res$ ($\equiv \, a\, +\, b\log \sigma \, +\, c\log I\, -\, \log R$, where a is the zero-point of the FP) is found to strongly correlate with stellar age, indicating that stellar age can be used as a crucial fourth parameter of the FP. However, we find that 4c + b + 2 = δ, where δ ∼ 0.8 for FPs in TNG, rather than zero as is typically inferred from observations. This implies that a tight power-law relation between the dynamical mass-to-light ratio Mdyn/L and the dynamical mass Mdyn (where Mdyn ≡ 5σ2R/G, with G being the gravitational constant) is not present in the TNG100 simulation. Recovering such a relation requires proper mixing between dark matter and baryons, as well as star formation occurring with correct efficiencies at the right mass scales. This represents a powerful constraint on the numerical models, which has to be satisfied in future hydrodynamical simulations.

Hypocognitive Mind: How Lack of Conceptual Knowledge Confines What People See and Remember

We examine hypocognition, in which people lack a cognitive or linguistic representation of a concept necessary to identify, interpret, or remember instances of it. Six studies (N = 2,085) revealed that hypocognition degrades retention of fundamental information in everyday living, such as frequency of encounter. Hypocognitive participants reported encountering instances of a concept less often compared to those who knew the concept (Study 1). They failed to discern the presence and encode the frequency of objects for which they were hypocognitive, such as American participants when observing exotic fruits (Studies 2A & 3) and alphabetic letters rendered as unfamiliar symbols (Studies 2B & 5). Hypocognition occurs across cultures: British participants tracked the frequency of Asian dumplings less accurately than Chinese participants, who tracked the frequency of cheese less accurately than the British (Study 4). Lacking an underlying concept impedes remembering even when novel verbal labels are present (Study 5). Finite channels of conceptual knowledge impose a powerful constraint on what people identify, recognize, and remember in their everyday environment. The concepts that people lack impoverish their experience with the world.

The Price Equation Program: Simple Invariances Unify Population Dynamics, Thermodynamics, Probability, Information and Inference

The fundamental equations of various disciplines often seem to share the same basic structure. Natural selection increases information in the same way that Bayesian updating increases information. Thermodynamics and the forms of common probability distributions express maximum increase in entropy, which appears mathematically as loss of information. Physical mechanics follows paths of change that maximize Fisher information. The information expressions typically have analogous interpretations as the Newtonian balance between force and acceleration, representing a partition between the direct causes of change and the opposing changes in the frame of reference. This web of vague analogies hints at a deeper common mathematical structure. I suggest that the Price equation expresses that underlying universal structure. The abstract Price equation describes dynamics as the change between two sets. One component of dynamics expresses the change in the frequency of things, holding constant the values associated with things. The other component of dynamics expresses the change in the values of things, holding constant the frequency of things. The separation of frequency from value generalizes Shannon’s separation of the frequency of symbols from the meaning of symbols in information theory. The Price equation’s generalized separation of frequency and value reveals a few simple invariances that define universal geometric aspects of change. For example, the conservation of total frequency, although a trivial invariance by itself, creates a powerful constraint on the geometry of change. That constraint plus a few others seem to explain the common structural forms of the equations in different disciplines. From that abstract perspective, interpretations such as selection, information, entropy, force, acceleration, and physical work arise from the same underlying geometry expressed by the Price equation.

Query Answering with Transitive and Linear-Ordered Data

We consider entailment problems involving powerful constraint languages such as frontier-guarded existential rules in which we impose additional semantic restrictions on a set of distinguished relations. We consider restricting a relation to be transitive, restricting a relation to be the transitive closure of another relation, and restricting a relation to be a linear order. We give some natural variants of guardedness that allow inference to be decidable in each case, and isolate the complexity of the corresponding decision problems. Finally we show that slight changes in these conditions lead to undecidability.

Planetary nebulae in the (extra)-galactic context: Probing chemical evolution in star-forming galaxies

The populations of planetary nebulae (PNe) probe metallicity and chemical content (and its evolution) of the parent galaxy, giving clues to galaxy formation and evolution. This sub-field of extra-galactic PN research has been particularly active in the recent years. Comparison of data and models yielded estimates of global cosmic enrichment and provided constraints to galaxy formation history. In external spiral galaxies, the chemical contents of PNe and H II regions can be compared to disclose possible evolution of the radial metallicity gradient, which is, in turn, a powerful constraint to galactic chemical evolutionary models. In the Milky Way, recent PN progenitor dating and new chemical abundances offer an updated look into our own Galaxy. Collectively, Galactic and extra-galactic radial metallicity gradients from emission-line probes (PNe and H II regions) can be compared to have a cosmological outlook on galactic evolution.