Co-Branding

Publisher website: http://www.e-elgar.co.uk/Professor Maniatis contributed 50% to this chapter.Professor Maniatis contributed 50% to this chapter.DISCLAIMER: This material is copyright protected and for personal use only.Professor Maniatis contributed 50% to this chapter.Professor Maniatis contributed 50% to this chapter.In this timely book, expert contributors address this controversial issue and identify the various points at which names are shared

Perceptual organization and consciousness

With chapter written by leading researchers in the field, this is the state-of-the-art reference work on this topic, and will be so for many years to come

Variability in visual cortex size reflects tradeoff between local orientation sensitivity and global orientation modulation

The surface area of early visual cortices varies several fold across healthy adult humans and is genetically heritable. But the functional consequences of this anatomical variability are still largely unexplored. Here we show that interindividual variability in human visual cortical surface area reflects a tradeoff between sensitivity to visual details and susceptibility to visual context. Specifically, individuals with larger primary visual cortices can discriminate finer orientation differences, whereas individuals with smaller primary visual cortices experience stronger perceptual modulation by global orientation contexts. This anatomically correlated tradeoff between discrimination sensitivity and contextual modulation of orientation perception, however, does not generalize to contrast perception or luminance perception. Neural field simulations based on a scaling of intracortical circuits reproduce our empirical observations. Together our findings reveal a feature-specific shift in the scope of visual perception from context-oriented to detail-oriented with increased visual cortical surface area

Non-gapped Fermi surfaces, quasiparticles and the anomalous temperature dependence of the near-EFE_F electronic states in the CMR oxide La2−2x_{2-2x}Sr1+2x_{1+2x}Mn2_2O7_7 with x=0.36x=0.36

After years of research into colossal magnetoresistant (CMR) manganites using bulk techniques, there has been a recent upsurge in experiments directly probing the electronic states at or near the surface of the bilayer CMR materials La$_{2-2x}$Sr$_{1+2x}$Mn$_2$O$_7$ using angle-resolved photoemission or scanning probe microscopy. Here we report new, temperature dependent, angle resolved photoemission data from single crystals with a doping level of $x=0.36$. The first important result is that there is no sign of a pseudogap in the charge channel of this material for temperatures below the Curie temperature $T_C$. The second important result concerns the temperature dependence of the electronic states. The temperature dependent changes in the Fermi surface spectra both at the zone face and zone diagonal regions in $k$-space indicate that the coherent quasiparticle weight disappears for temperatures significantly above $T_C$, and that the $k$-dependence of the T-induced changes in the spectra invalidate an interpretation of these data in terms of the superposition of a `universal' metallic spectrum and an insulating spectrum whose relative weight changes with temperature. In this sense, our data are not compatible with a phase separation scenario.Comment: 6 pages, 4 figure

Investigating Representations of Facial Identity in Human Ventral Visual Cortex with Transcranial Magnetic Stimulation

The occipital face area (OFA) is face-selective. This enhanced activation to faces could reflect either generic face and shape-related processing or high-level conceptual processing of identity. Here we examined these two possibilities using a state-dependent transcranial magnetic stimulation (TMS) paradigm. The lateral occipital (LO) cortex which is activated non-selectively by various types of objects served as a control site. We localized OFA and LO on a per-participant basis using functional MRI. We then examined whether TMS applied to either of these regions affected the ability of participants to decide whether two successively presented and physically different face images were of the same famous person or different famous people. TMS was applied during the delay between first and second face presentations to investigate whether neuronal populations in these regions played a causal role in mediating the behavioral effects of identity repetition. Behaviorally we found a robust identity repetition effect, with shorter reaction times (RTs) when identity was repeated, regardless of the fact that the pictures were physically different. Surprisingly, TMS applied over LO (but not OFA) modulated overall RTs, compared to the No-TMS condition. But critically, we found no effects of TMS to either area that were modulated by identity repetition. Thus, we found no evidence to suggest that OFA or LO contain neuronal representations selective for the identity of famous faces which play a causal role in identity processing. Instead, these brain regions may be involved in the processing of more generic features of their preferred stimulus categories

Epidemic spreading in evolving networks

A model for epidemic spreading on rewiring networks is introduced and analyzed for the case of scale free steady state networks. It is found that contrary to what one would have naively expected, the rewiring process typically tends to suppress epidemic spreading. In particular it is found that as in static networks, rewiring networks with degree distribution exponent $\gamma >3$ exhibit a threshold in the infection rate below which epidemics die out in the steady state. However the threshold is higher in the rewiring case. For $2<\gamma \leq 3$ no such threshold exists, but for small infection rate the steady state density of infected nodes (prevalence) is smaller for rewiring networks.Comment: 7 pages, 7 figure

How geckos stick in nature: ecology and biomechanics of gecko feet

Phenotype and performance play a fundamental role in evolution and ecology. Studies of form and function often use correlations between morphology, performance, and habitat use to examine patterns of ecomorphology and morphological adaptation. Geckos, of the taxonomic group Gekkota, are an understudied yet diverse clade of lizards in which studies of form and function would greatly improve our understanding of their evolution. Geckos have the rather unique trait of adhesive toe pads, enabling them to use arboreal and rocky environments in a way few other creatures can. Gecko toe pad morphology and adhesive abilities are highly variable across species, suggesting ecological adaptations may have driven their evolution, yet few studies has considered gecko adhesive morphology and performance in an ecological context. In this study, we quantified morphology, adhesive performance, and habitat use of 13 gecko species from Queensland, Australia including tropical, arid, arboreal, and rock-dwelling species. We found toe detachment angle to be correlated with residual limb length. We also found residual limb length to be correlated with the use of arboreal and rock microhabitats as well as negatively correlated with perch diameter. This study is one of the first examples investigating gecko adhesive performance and specific microhabitat parameters. We suggest additional comparative studies investigating gecko limb kinematics and setal mechanics to corroborate our observational results

The toad less travelled: comparing life histories, ecological niches, and potential habitat of Asian black-spined toads and cane toads

Context: Invasive vertebrates have significant negative impacts on biodiversity and agricultural production worldwide. Increased connectivity among countries, through trade and tourism, is escalating the rate of introductions of vertebrate species, particularly herpetofauna, across international borders. In Australia, Asian black-spined toads (ABSTs; Duttaphrynus melanostictus) are one of the species most intercepted at borders. They are considered a biosecurity risk because of the potential for negative environmental impacts, similar to those caused by cane toads (Rhinella marina).Aims: We aimed to compare ABSTs with cane toads to investigate potential impacts and distribution of ABSTs in the Australian context. We also aimed to identify knowledge gaps regarding ABST biology and the potential role of cane toads in an ABST invasion in Australia.Methods: We undertook a literature review to obtain published data to compare the life history characteristics of ABSTs and cane toads. We also modelled climatic niche overlap and compared suitable habitat for both species in Australia.Key results: Our results show ABSTs and cane toads have broadly similar reproductive life histories and feeding niches. In particular, similarities include large clutch sizes, preferred oviposition sites, and diet at tadpole and adult life stages. In Australia, the species share suitable potential habitat, particularly in North Queensland, where the majority of ABST incursions have occurred. The species differ in size, call characteristics, clutch size relative to body size, and egg development rate, although the environment also influences these traits. We identify gaps in our knowledge of ABST spatial ecology, thermal tolerances, water reliance, and habitat.Conclusions: ABSTs pose a significant biosecurity threat to Australia. Similarities in life history to cane toads means they may have similar impacts, but may have a more limited distribution in Australia. Invasion of Australia by ABSTs would likely result in interactions with cane toads, but it is not possible to accurately determine the outcomes of those interactions without further investigation.Implications: Addressing knowledge gaps and quantitatively determining the potential for competition between ABSTs and cane toads will assist surveillance and response planning for ABST incursions in Australia

Characteristics and robustness of Agulhas leakage estimates: an inter-comparison study of Lagrangian methods

The inflow of relatively warm and salty water from the Indian Ocean into the South Atlantic via Agulhas leakage is important for the global overturning circulation and the global climate. In this study, we analyse the robustness of Agulhas leakage estimates as well as the thermohaline property modifications of Agulhas leakage south of Africa. Lagrangian experiments with both the newly developed tool Parcels and the well established tool Ariane were performed to simulate Agulhas leakage in the eddy-rich ocean–sea-ice model INALT20 (1/20∘ horizontal resolution) forced by the JRA55-do atmospheric boundary conditions. The average transport, its variability, trend and the transit time from the Agulhas Current to the Cape Basin of Agulhas leakage is simulated comparably with both Lagrangian tools, emphasizing the robustness of our method. Different designs of the Lagrangian experiment alter in particular the total transport of Agulhas leakage by up to 2 Sv, but the variability and trend of the transport are similar across these estimates. During the transit from the Agulhas Current at 32∘ S to the Cape Basin, a cooling and freshening of Agulhas leakage waters occurs especially at the location of the Agulhas Retroflection, resulting in a density increase as the thermal effect dominates. Beyond the strong air–sea exchange around South Africa, Agulhas leakage warms and salinifies the water masses below the thermocline in the South Atlantic

Feeding of golden-mantled ground squirrels by park visitors at Crater Lake National Park

Interaction between the golden-mantled ground squirrel and park visitors at a highly visited portion of the Rim Village area of Crater Lake National Park was studied. Observations were made of the total number of visitors entering the area, age, sex, and group composition of visitors who fed the squirrels, type of food offered, how long visitors fed the squirrels, and whether the feeders were themselves eating or taking pictures of the squirrels. Approximately half of those visitors feeding squirrels were under the age of twenty. The effectiveness of signs in deterring visitor feeding was studied. A sign stressing the danger to humans of bubonic plague was twice as effective in deterring feeding as one emphasizing the welfare of the squirrel, and the latter sign was twice as effective in deterring feeding as having no sign at all