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Sealing in light cream terracotta, showing a seated female figure on a throne, with an inscription; impresson made from a coin (of the Kuṣāṇa king Vasishka, circa CE 246-67); on the reverse, the residual impression of a document

Sealing in light cream terracotta, showing a seated female figure on a throne, with an inscription; impresson made from a coin (of the Kuṣāṇa king Vasishka, circa CE 246-67); on the reverse, the residual impression of a document. British Museum 1960,0517.1.17.

Sealing. Two-sided circular sealing in terracotta; on one side a trident and one line inscription below; on the reverse a trident and second inscription below. Impressions of string round the edge.

Sealing. Two-sided circular sealing in terracotta; on one side a trident and one line inscription below; on the reverse a trident and second inscription below. Impressions of string round the edge. British Museum 2005,0814.6.

Sealing in terracotta with on one a trident and one line inscription below; to the right an oval object with a looped edge. Line impression on the reverse.

Sealing in terracotta with on one a trident and one line inscription below; to the right an oval object with a looped edge. Line impression on the reverse. British Museum 2005,0814.4.

Sealing. Circular sealing in terracotta with a two line inscription; above a discus. On the reverse a hooked device, possibly an elephant goad.

Sealing. Circular sealing in terracotta with a two line inscription; above a discus. On the reverse a hooked device, possibly an elephant goad. British Museum 2005,0814.11.

Data set for "Dynamic perceptual feature selectivity in primary somatosensory cortex upon reversal learning"

This repository contains the data used to generate the figures and well as the main codes that were used for analyses.

Wavelet Domain Compensation of Frequency Dispersion of UWB Electromagnetic Waves for Time-Reversal Imaging (dataset)

These files are the simulation data used to create the figures illustrated in the relevant journal paper. Each filename indicates which figure number it relates to. These files are text files. The first row in each file describes the content of each of its columns.

opencc-by-4.0Jul 2020View details →

Data for 'Complete reversal of the atomic unquenched orbital moment by a single electron'

This folder contains all the raw data needed to generate the figures in the paper 'Complete reversal of the atomic unquenched orbital moment by a single electron.' Contents:  Figure 1  (a) STM topography 'Fig1Topography.sxm' (b) and (c) DFT calculations, reproduced with 'public_sis2.pw.in' and the Quantum ESPRESSO package. Figure 2  (a) Energy levels (in meV) for the spin-orbit Hamiltonian, reproduced using 'Fig2spectra_SM'; multiplet calculations from the point-charge model found in 'Fig2spectra_PCM.'  Please note that .out files can be opened with any text editor (e.g. such as TextEdit), and .tar files can be unpacked with any open-source file archiver (e.g. such as 7-zip). (b) dI/dV spectra atop Fe atom and bare Cu2N: 'Fig2Spec_MonomerFullRange' and 'Fig2Spec_CuNFullRange' Figure 3 (a) and (b) field dependence of the spin excitation, with data files 'SJ30_001-036', for 0-4T. Field values indicated in data files. (c) 1T-5T data of orbital excitation, in order of increasing field: 'Fig4Spec_1T', 'Fig4Spec_2T', 'Fig4Spec_3T', 'Fig4Spec_4T', 'Fig4Spec_5T.' PCM transport calculations also provided.  (d) Zeeman splitting data in 'ShiftwField' Figure 4 (a) and (b) current sweeps, with data files 'S_J31_016-032'. Current values indicated in data files. (c) Measured data 'Fig4MonomerSpectrum.' Point-charge transport calculations in 'PCMTransport.' Spin-orbit transport calculations in 'SOTransport.' (d) Point-charge calculations in 'Occupations', first column is the Bias (mv), second column is the occupation of the ground state, and third column is occupation of the first excited state.

opencc-zeroAug 2020View details →

Male competition reverses female preference for male chemical cues

Females must choose among potential mates with different phenotypes in a variety of social contexts. Many male traits are inherent and unchanging, but others are labile to social context. Competition, for example, can cause physiological changes that reflect recent wins and losses which fluctuate throughout time. We may expect females to respond differently to males depending on the outcome of their most recent fight. In Bolitotherus cornutus (forked fungus beetles), males compete for access to females, but copulation requires female cooperation. In this study we use behavioural trials to determine if females use chemical cues to differentiate between males and if the outcome of recent male competition alters female preference. We measured female association time with chemical cues of two size-matched males both before and after male-male competition. Females in our study preferred to associate with future losers before males interacted, but changed their preference for realized winners following male competitive interactions. Our study provides the first evidence of change in female preference based solely on the outcome of male-male competition.

opencc-zeroAug 2020View details →

Data from: Variant files for genotypic and sex-reversed males

X and Y chromosomes are usually derived from a pair of homologous autosomes, which then diverge from each other over time. Although Y-specific features have been characterized in sex chromosomes of various ages, the earliest stages of Y chromosome evolution remain elusive. In particular, we do not know whether early stages of Y chromosome evolution consist of changes to individual genes or happen via chromosome-scale divergence from the X. To address this question, we quantified divergence between young proto-X and proto-Y chromosomes in the house fly, Musca domestica. We compared proto-sex chromosome sequence and gene expression between genotypic (XY) and sex-reversed (XX) males. We find evidence for sequence divergence between genes on the proto-X and proto-Y, including five genes with mitochondrial functions. There is also an excess of genes with divergent expression between the proto-X and proto-Y, but the number of genes is small. This suggests that individual proto-Y genes, but not the entire proto-Y chromosome, have diverged from the proto-X. We identified one gene, encoding an axonemal dynein assembly factor (which functions in sperm motility), that has higher expression in XY males than XX males because of a disproportionate contribution of the proto-Y allele to gene expression. The up-regulation of the proto-Y allele may be favored in males because of this gene's function in spermatogenesis. The evolutionary divergence between proto-X and proto-Y copies of this gene, as well as the mitochondrial genes, is consistent with selection in males affecting the evolution of individual genes during early Y chromosome evolution.

opencc-zeroSep 2020View details →

Geometric model for toppling-prone deformation of layered reverse-dip slope

This paper concentrates on analyzing toppling response of layered reverse-dip slope under the action of geometric feature factors of slope angle, strata thickness and strata dip, so as to establish toppling-prone geometric model for toppling deformation. To achieve this, a total of 144 kinds of combination schemes performed by numerical simulation are carried out on three secondary factors of slope angle and strata dip and thickness. The toppling response of reverse dip slope under the effect of geometric feature factors is obtained using numerical simulation software UDEC. Then a model for toppling prediction is designed by utilizing support vector machine, and followed by a geometric model for possible toppling of reverse-dip slope. The research shows that the geometric model is a quarter of a spheroid with a slope angle of 80°, a strata dip of 80°, and a strata thickness of 0.19 m as the center. The length of the long equatorial radius of the spheroid is 31° (strata dip axial), that of the short equatorial radius is 21° (slope angle axial), and the polar radius is 0.075 m (strata thickness axial), and the ratio of long equatorial radius, short equatorial radius and polar radius is 2.48:1.68:1.00.

opencc-by-4.0Jan 2021View details →

Reversing dune

The data in manuscript.

opencc-zeroDec 2011View details →

Data from: Differential investment in pre- versus post-copulatory sexual selection reinforces a cross-continental reversal of sexual size dimorphism in Sepsis punctum (Diptera: Sepsidae)

Theory predicts that males have a limited amount of resources to invest in reproduction, suggesting a trade-off between traits that enhance mate acquisition and those enhancing fertilization success. Here we investigate the relationship between pre- and post-copulatory investment by comparing the mating behavior and reproductive morphology of four European and five North American populations of the dung fly Sepsis punctum (Diptera) that display a reversal of sexual size dimorphism (SSD). We show that the geographic reversal in SSD between the continents (male-biased in Europe, female-biased in North America) is accompanied by differential investment in pre- versus post-copulatory traits. We find higher re-mating rates in European populations, where larger males acquire more matings and consequently have evolved relatively larger testes and steeper hyper-allometry with body size. American populations, in sharp contrast, display much reduced, if any, effect of body size on those traits. Instead, North American males demonstrate an increased investment in mate acquisition prior to copulation, with more mounting attempts and a distinctive abdominal courtship display that is completely absent in Europe. When controlling for body size, relative female spermathecal size is similar on both continents, so we find no direct evidence for the co-evolution of male and female internal reproductive morphology. By comparing allopatric populations of the same species that apparently have evolved different mating systems and consequently SSD, we thus indirectly demonstrate differential investment in pre- vs. post-copulatory mechanisms increasing reproductive success.

opencc-zeroDec 2017View details →

Data from: Abundance-dependent effects of neighborhood dissimilarity and growth rank reversal in a Neotropical forest

Why tropical forests harbor an exceptional number of species with striking differences in abundances remains an open question. We propose a theoretical framework to address this question in which rare species may have different extirpation risks depending on species ranks in tree growth and sensitivities to neighborhood interactions. To evaluate the framework, we studied tree growth and its responses to neighborhood dissimilarity (ND) in traits and phylogeny for 146 species in a Neotropical forest. We found that tree growth was positively related to ND, and common species were more strongly affected by ND than rare species, which may help delay dominance of common species. Rare species grew more slowly at the community-wide average ND than common species. But rare species grew faster when common species tended to dominate locally, which may help reduce extirpation risk of rare species. Our study highlights that tree growth rank among species depends on their responses to neighborhood interactions, which can be important in fostering diversity maintenance in tropical forests.

opencc-zeroDec 2011View details →

Data from: Slowly switching between environments facilitates reverse evolution in small populations

Natural populations must constantly adapt to ever-changing environmental conditions. A particularly interesting question is whether such adaptations can be reversed by returning the population to an ancestral environment. Such evolutionary reversals have been observed in both natural and laboratory populations. However, the factors that determine the reversibility of evolution are still under debate. The timescales of environmental change vary over a wide range, but little is known about how the rate of environmental change influences the reversibility of evolution. Here we demonstrate computationally that slowly switching between environments increases the reversibility of evolution for small populations, which are subject to only modest clonal interference. For small populations, slow switching reduces the mean number of mutations acquired in a new environment and also increases the probability of reverse evolution at each of these "genetic distances." As the population size increases, slow switching no longer reduces the genetic distance, thus decreasing the evolutionary reversibility. We confirm this effect using both a phenomenological model of clonal interference and also a Wright-Fisher stochastic simulation that incorporates genetic diversity. Our results suggest that the rate of environmental change is a key determinant of the reversibility of evolution, and provides testable hypotheses for experimental evolution.

opencc-zeroDec 2012View details →

Data from: Evolutionary reversals of antibiotic resistance in experimental populations of Pseudomonas aeruginosa

Antibiotic resistance mutations are accompanied by a fitness cost, and two mechanisms allow bacteria to adapt to this cost once antibiotic use is halted. First, it is possible for resistance to revert; second, it is possible for bacteria to adapt to the cost of resistance by compensatory mutations. Unfortunately, reversion to antibiotic sensitivity is rare, but the underlying factors that prevent reversion remain obscure. Here, we directly study the evolutionary dynamics of reversion by experimentally mimicking reversion mutations—sensitives—in populations of rifampicin-resistant Pseudomonas aeruginosa. We show that, in our populations, most sensitives are lost due to genetic drift when they are rare. However, clonal interference from lineages carrying compensatory mutations causes a dramatic increase in the time to fixation of sensitives that escape genetic drift, and mutations surpassing the sensitives' fitness are capable of driving transiently common sensitive lineages to extinction. Crucially, we show that the constraints on reversion arising from clonal interference are determined by the potential for compensatory adaptation of the resistant population. Although the cost of resistance provides the incentive for reversion, our study demonstrates that both the cost of resistance and the intrinsic evolvability of resistant populations interact to determine the rate and likelihood of reversion.

opencc-zeroDec 2017View details →

Data from: The quick are the dead: pheasants that are slow to reverse a learned association survive for longer in the wild

Cognitive abilities likely evolve through natural selection if they provide individuals with fitness benefits. A growing number of studies demonstrate a positive relationship between performance in psychometric tasks and (proxy) measures of fitness. We assayed the performance of 154 Common Pheasant Phasianus colchicus chicks on tests of acquisition and reversal learning, using a different set of chicks and different set of cue types (spatial location and colour) in each of two years and then followed their fates after release into the wild. Across all birds, individuals that were slow to reverse previously learned associations were more likely to survive to four months old. For heavy birds, individuals that rapidly acquired an association had improved survival to four months, whereas for light birds, slow acquirers were more likely to be alive. Slow reversers also exhibited less exploratory behaviour in assays when five weeks old. Fast acquirers visited more artificial feeders after release. By contrast to most other studies, we showed that apparently 'poor' cognitive performance (slow reversal speed suggesting low behavioural flexibility) correlates with fitness benefits in at least some circumstances. This correlation suggests a novel mechanism by which continued exaggeration of cognitive abilities may be constrained.

opencc-zeroDec 2015View details →

Data from: Chemogenetic inhibition of the medial prefrontal cortex reverses the effects of REM sleep loss on sucrose consumption

Rapid eye movement (REM) sleep loss is associated with increased consumption of weight-promoting foods. The prefrontal cortex (PFC) is thought to mediate reward anticipation. However, the precise role of the PFC in mediating reward responses to highly palatable foods (HPF) after REM sleep deprivation is unclear. We selectively reduced REM sleep in mice over a 25–48 hr period and chemogenetically inhibited the medial PFC (mPFC) by using an altered glutamate-gated and ivermectin-gated chloride channel that facilitated neuronal inhibition through hyperpolarizing infected neurons. HPF consumption was measured while the mPFC was inactivated and REM sleep loss was induced. We found that REM sleep loss increased HPF consumption compared to control animals. However, mPFC inactivation reversed the effect of REM sleep loss on sucrose consumption without affecting fat consumption. Our findings provide, for the first time, a causal link between REM sleep, mPFC function and HPF consumption.

opencc-zeroDec 2010View details →

Data from: Reverse evolution: selection against costly resistance in disease-free microcosm populations of Paramecium caudatum

Evolutionary costs of parasite resistance arise if genes conferring resistance reduce fitness in the absence of parasites. Thus, parasite-mediated selection may lead to increased resistance and a correlated decrease in fitness, whereas relaxed parasite-mediated selection may lead to reverse evolution of increased fitness and a correlated decrease in resistance. We tested this idea in experimental populations of the protozoan Paramecium caudatum and the parasitic bacterium Holospora undulata. After 8 years, resistance to infection and asexual reproduction were compared among paramecia from (i) infected populations, (ii) uninfected naive populations and (iii) previously infected, parasite-free (recovered) populations. Paramecia from infected populations were more resistant (+12%), but had lower reproduction (-15%) than naive paramecia, indicating an evolutionary trade-off between resistance and fitness. Recovered populations showed similar reproduction to naive populations; however, resistance of recently (<3 years) recovered populations was similar to paramecia from infected populations, while longer (>3 years) recovered populations were as susceptible as naive populations. This suggests a weak, convex trade-off between resistance and fitness, allowing recovery of fitness, without complete loss of resistance, favouring the maintenance of a generalist strategy of intermediate fitness and resistance. Our results indicate that (co)evolution with parasites can leave a genetic signature in disease-free populations.

opencc-zeroDec 2015View details →

Data from: Neuroendocrine correlates of sex-role reversal in barred buttonquails

Sex differences in brain structure and behaviour are well documented among vertebrates. An excellent model exploring the neural mechanisms of sex differences in behaviour is represented by sex-role-reversed species. In the majority of bird species, males compete over access to mates and resources more strongly than do females. It is thought that the responsible brain regions are therefore more developed in males than in females. Because these behaviours and brain regions are activated by androgens, males usually have increased testosterone levels during breeding. Therefore, in species with sex-role reversal, certain areas of the female brain should be more developed or steroid hormone profiles should be sexually reversed. Here, I studied circulating hormone levels and gene expression of steroid hormone receptors and aromatase in a captive population of barred buttonquails (Turnix suscitator). While females performed courtship and agonistic behaviours, there was no evidence for sexually reversed hormone profiles. However, I found female-biased sex differences in gene expression of androgen receptors in several hypothalamic and limbic brain regions that were already in place at hatching. Such sex differences are not known from non-sex-role-reversed species. These data suggest that increased neural sensitivity to androgens could be involved in the mechanisms mediating sex-role-reversed behaviours.