Phylogenetic, ecological and intraindividual variability patterns in grass phytolith shape

Grass silica short cell (GSSC) phytoliths appear to be the most reliable source of fossil evidence for tracking the evolutionary history and paleoecology of grasses. In recent years, modern techniques have been used to quantitatively assess phytolith shape variation. This progress has widened opportunities with respect to the classification of grass fossil phytoliths. However, phylogenetic, ecological and intraindividual variability patterns in phytolith shape remain largely unexplored. The full range of intraindividual phytolith shape variation (3650 2D outlines) from 73 extant grass species, 48 genera, 18 tribes, and 8 subfamilies (with special attention paid to Pooideae) was analysed using the geometric morphometric analysis based on the semilandmarks spanning phytolith outlines. Although we showed that 2D phytolith shape is mainly driven by deep-time diversification of grass subfamilies, a closer look uncovered distinct phytolith shape variation in early-diverging lineages of Pooideae. The phylogenetic pattern in phytolith shape was successfully revealed by applying geometric morphometrics to 2D phytolith shape outlines. This finding strengthens the potential of phytoliths to track the evolutionary history and paleoecology of grasses. Moreover, geometric morphometrics of 2D phytolith shape proved to be an excellent tool for analysis requiring large sums of phytolith outlines, making it useful for quantitative palaeoecological reconstruction.

Securely Sharing Randomized Code that Flies

Address Space Layout Randomization (ASLR) was a great role model being a light-weight defense technique that could prevent early return-oriented programming attacks. Simple yet effective, ASLR was quickly widely-adopted. Conversely, today only a trickle of defense techniques are being integrated or adopted mainstream. As code reuse attacks have evolved, defenses have strived to keep up. To do so, many have had to take unfavorable tradeoffs like using background threads or protecting only a subset of sensitive code. In reality, these tradeoffs were unavoidable steps necessary to improve the strength of the state-of-the-art. We present Goose, an on-demand system-wide runtime re-randomization technique capable of scalable protection of application as well as shared library code most defenses have forgone. We achieve code sharing with diversification by implementing reactive and scalable, rather than continuous or one-time diversification. Enabling code sharing further removes redundant computation like tracking, patching, along with memory overheads required by prior randomization techniques. In its baseline state, the code transformations needed for Goose security hardening incur a reasonable performance overhead of 5.5% on SPEC and minimal degradation of 4.4% in NGINX, demonstrating its applicability to both compute-intensive and scalable real-world applications. Even when under attack, Goose only adds from less than 1% up to 15% depending on application complexity.

Equity market anomalies in major European economies

This paper investigates five leading equity market anomalies – size, value, momentum, profitability, and asset growth, for four Western European markets, namely, Germany, France, Italy and Spain, from January 2002 to March 2018. The study tests whether these anomalies reverse under different macro-economic uncertainty conditions, and evaluates if strategies based on time diversification can be formed using these equity market anomalies. Market anomalies were tested using four major asset pricing models – the Capital Asset Pricing Model, the Fama-French three-factor model, the Carhart model, and the Fama-French five-factor model. Macro-economic uncertainty was tested using two proxies, namely VIX and default premiums. Time diversified strategies were examined by estimating Sharpe ratios of combined portfolios formed by combining winner univariate portfolios. Value effect in Germany, Size effect in France and Profitability effect in Italy and Spain provide the highest unadjusted returns on long side strategies. No significant reversal of these anomalies was found under different macroeconomic uncertainties. Asset pricing tests show that CAPM works well for Spain and Italy, while Carhart’s model explains returns in Germany. The Fama-French five factor model does not seem to be a good descriptor of asset pricing for data. No suitable model for explaining asset returns is identified for France. Finally, it is observed that some of the equity market anomalies seem to be countercyclical and therefore provide time diversification opportunities. The study has implications for academicians, investors, and policy makers by providing insights for developing profitable investment strategies and highlighting the efficacy of alternative models as performance benchmarks.

A measure of innovation performance: the Innovation Patent Index

PurposeThe measure of companies' Innovation Performance is fundamental for enhancing the value and decision-making processes of firms. The purpose of this paper is to present a new measure of Innovation Performance, called Innovation Patent Index (IPI), which makes it possible to quantitatively summarize different aspects of firms' innovation.Design/methodology/approachIn order to define the IPI, a secondary source, i.e. patent data, has been used. The five dimensions of IPI, i.e. efficiency, time, diversification, quality and internationalization have been defined both analyzing the literature and applying three different machine learning algorithms (regularized least squares, deep neural networks and decision trees), considering patent forward citations as a proxy of the innovation performance.FindingsResults show that the IPI index is a very useful tool, simple to use and very promptly. In fact, it is possible to get important results without making time consuming analysis with primary sources. It is a tool that can be used by managers, businessmen, policymakers, organizations, patent experts and financiers to evaluate and plan future activities, to enhance the innovation capability, to find financing and to support and improve innovation.Research limitations/implicationsPatent data are not widely used in all the sectors. Moreover, the pure number of forward citations is not the only forward looking indicator suggested by the literature.Originality/valueThe demand for a useable Innovation Performance tool, as well as the lack of tools able to grasp different aspects of the innovation, highlight the need to develop new instruments. In fact, although previous studies provide several measures of Innovation Performance, these are often difficult for managers to use, do not appreciate different aspects of the innovation and are not forward looking.

Desert lizard diversity worldwide: effects of environment, time, and evolutionary rate

ABSTRACTBiodiversity is not uniformly distributed across the Earth’s surface, even among physiographically comparable biomes in different biogeographic regions. For lizards, the world’s large desert regions are characterized by extreme heterogeneity in species richness, spanning some of the most species-rich (arid Australia) and species-poor (central Asia) biomes overall. Regional differences in species diversity may arise as a consequence of the interplay of several factors (e.g., evolutionary time, diversification rate, environment), but their relative importance for biogeographic patterns remains poorly known. Here we use distributional and phylogenetic data to assess the evolutionary and ecological drivers of large-scale variation in desert lizard diversity. We specifically test whether diversity patterns are best explained by differences in the ages of arid-adapted lineages (evolutionary time hypothesis), by regional variation in speciation rate, by geographic area of the arid systems, and by spatial variation related to environment (climate, topography, and productivity). We found no effect of recent speciation rate and geographic area on differences in desert lizard diversity. We demonstrate that the extreme species richness of the Australian deserts cannot be explained by greater evolutionary time, because species began accumulating more recently there than in more species-poor arid regions. We find limited support for relationships between regional lizard richness and environmental variables, especially temperature, but these effects were inconsistent across deserts. Our results provide evidence against several classic hypotheses for interregional variation in species richness, but also highlight the complexity of processes underlying vertebrate community richness in the world’s great arid systems.

Time, diversification, and dispersal on the Australian continent

Sahul, the ancient continent uniting Australia and New Guinea, is the only inhabited continent uniquely occupied by small-scale societies until colonial contact. And Australia (only separated from New Guinea for 10,000 years) is the only continent exclusively occupied by hunter-gatherers. This makes Sahul, and Australia, crucial for understanding how language has evolved through our deep human past. This chapter addresses three enigmas: first the discrepancy in deep linguistic diversity and typological disparity between the Australian and New Guinea hemi-continents (1 maximal clade in Australia, over 50 in New Guinea), second the apparent relatedness of all Australian indigenous languages despite continuous human occupation for 60,000 years with no external intrusions, and third the recent spread of the Pama-Nyungan branch of the Australian family over seven-eighths of the continent, most likely in the mid-Holocene?

A Wavelet-Based Analysis of the Co-Movement between Sukuk Bonds and Shariah Stock Indices in the GCC Region: Implications for Risk Diversification

Investors are interested in knowing whether sukuk bonds and shariah stock indices in the Gulf Corporation Council (GCC) region are related. This study examines the connectedness between the sukuk- and shariah-compliant stock indices in the GCC financial markets. Bivariate and multivariate wavelet approaches are applied to the daily data covering the period 10 July 2008 to 15 May 2017. The empirical findings demonstrate a strong correlation between these GCC sukuk bond indices and shariah stock indices. The degree of connectedness between these sukuk and shariah stock indices varies across time and scale. A strong and positive association is observed in the short term and a negative association is evident in the long term. The same findings are observed, using the wavelet cohesion approach that also validates the existence of portfolio diversification opportunities at a short-time horizon. The multivariate cross-correlation analysis reveals that these sukuk and shariah stock markets are highly integrated across time and scale. Furthermore, the value at risk (VaR) for the sukuk bond–shariah stocks portfolio is performed to highlight the significance of the wavelet analysis. The outcomes show that portfolio stocks are variable with respect to time or scale (time diversification). Overall, analyzing the sukuk bond–shariah stock index returns in the GCC at a multiscale level makes it easier for financial agents dealing with heterogeneous trading horizons to assess the benefits of diversifications.