Stochasticity and evolutionary stability

In stochastic dynamical systems, different concepts of stability can be obtained in different limits. A particularly interesting example is evolutionary game theory, which is traditionally based on infinite populations, where strict Nash equilibria correspond to stable fixed points that are always evolutionarily stable. However, in finite populations stochastic effects can drive the system away from strict Nash equilibria, which gives rise to a new concept for evolutionary stability. The conventional and the new stability concepts may apparently contradict each other leading to conflicting predictions in large yet finite populations. We show that the two concepts can be derived from the frequency dependent Moran process in different limits. Our results help to determine the appropriate stability concept in large finite populations. The general validity of our findings is demonstrated showing that the same results are valid employing vastly different co-evolutionary processes

KETAHANAN TARIK CAMPURAN CTRB YANG MENGANDUNG 60% RAP DAN 40% RAM DENGAN SUBSTITUSI MATERIAL POZOLAN TERHADAP SEMEN

Kerusakan jalan yang terjadi pada lapis pondasi maka rehabilitasi yang harus dilakukan pada lapis pondasinya. Perbaikan yang sering dikakukan yaitu membongkar lapis pondasi yang rusak lalu menggantinya dengan material agregat batu pecah yang baru tanpa menggunakan bahan pengikat maupun menggunakan bahan pengikat berupa semen lalu dipadatkan. Dalam pelaksanaannya di lapangan, cara ini sering menghadapi tantangan yaitu secara ekonomi memerluka dana yang besar untuk pengadaan material baru, gangguan lingkungan hidup yaitu mengakibatkan daerah quarry, polusi udara dan degradasi lingkngan. Untuk mengatasi masalah tersebut maka salah satu teknologi daur ulang yaitu CTRB dapat digunakan. Campuran Cemen Treated Recycling Base (CTRB) adalah teknik daur ulang perkerasan jalan untuk lapis pondasi yang memanfaatkan RAP (Reclaimed Asphalt Pavement) yaitu material agregat yang mengandung aspal dan RAM (Reclaimed Aggregate Mineral) yaitu material agregat yang tidak mengandung aspal yang berasal dari garukan perkerasan yang telah rusak, dicampur kembali lalu distabilisasikan dengan semen. Semen sebagai bahan stabilisa pada campuran CTRB memerluka biaya yang besar. Oleh sebab itu akan disubstitusikan pozolan alam (tras) terhadap semen. Dalam penelitian ini dilakukan pengujian ITS (Indirect Tensile Strength). Dalam penelitian ini akukan dilpengujian ITS (Indirect Tensile Strength). Variasi semen yang dibuat yaitu 2%, 4%, 6%  terhadap RAP dan RAM dan variasi tras  0%, 15%, 30% terhadap semen. Variasi campuran semen dan tras yaitu 2% PC, 4% PC, 6% PC, 2% PC : 15% Tras, 4% PC : 15% Tras, 6% PC : 15% Tras, 2% PC : 30% Tras, 4% PC : 30% Tras, 6% PC : 30% Tras. Komposisi optimum campuran yang melampaui nilai ITS yaitu campuran CTRB 6% PC : 15 % Tras dan 6% PC : 30% Tras Kata Kunci: CTRB, RAP, RAM, Tras, ITS, Pozzola

Statistical Communication Theory

Contains reports on four research projects

Statistical Communication Theory

Contains research objectives and reports on eight research projects

Transformation in a changing climate: a research agenda

The concept of transformation in relation to climate and other global change is increasingly receiving attention. The concept provides important opportunities to help examine how rapid and fundamental change to address contemporary global challenges can be facilitated. This paper contributes to discussions about transformation by providing a social science, arts and humanities perspective to open up discussion and set out a research agenda about what it means to transform and the dimensions, limitations and possibilities for transformation. Key focal areas include: (1) change theories, (2) knowing whether transformation has occurred or is occurring; (3) knowledge production and use; (4), governance; (5) how dimensions of social justice inform transformation; (6) the limits of human nature; (7) the role of the utopian impulse; (8) working with the present to create new futures; and (9) human consciousness. In addition to presenting a set of research questions around these themes the paper highlights that much deeper engagement with complex social processes is required; that there are vast opportunities for social science, humanities and the arts to engage more directly with the climate challenge; that there is a need for a massive upscaling of efforts to understand and shape desired forms of change; and that, in addition to helping answer important questions about how to facilitate change, a key role of the social sciences, humanities and the arts in addressing climate change is to critique current societal patterns and to open up new thinking. Through such critique and by being more explicit about what is meant by transformation, greater opportunities will be provided for opening up a dialogue about change, possible futures and about what it means to re-shape the way in which people live

Statistical Communication Theory

Contains reports on nine research projects

Statistical Communication Theory

Contains reports on six research projects

On the generalized linear equivalence of functions over finite fields

In this paper we introduce the concept of generalized linear equivalence between functions defined over finite fields; this can be seen as an extension of the classical criterion of linear equivalence, and it is obtained by means of a particular geometric representation of the functions. After giving the basic definitions, we prove that the known equivalence relations can be seen as particular cases of the proposed generalized relationship and that there exist functions that are generally linearly equivalent but are not such in the classical theory. We also prove that the distributions of values in the Difference Distribution Table (DDT) and in the Linear Approximation Table (LAT) are invariants of the new transformation; this gives us the possibility to find some Almost Perfect Nonlinear (APN) functions that are not linearly equivalent (in the classical sense) to power functions, and to treat them accordingly to the new formulation of the equivalence criterion

Intrinsic Differences in Spatiotemporal Organization and Stromal Cell Interactions Between Isogenic Lung Cancer Cells of Epithelial and Mesenchymal Phenotypes Revealed by High-Dimensional Single-Cell Analysis of Heterotypic 3D Spheroid Models

The lack of inadequate preclinical models remains a limitation for cancer drug development and is a primary contributor to anti-cancer drug failures in clinical trials. Heterotypic multicellular spheroids are three-dimensional (3D) spherical structures generated by self-assembly from aggregates of two or more cell types. Compared to traditional monolayer cell culture models, the organization of cells into a 3D tissue-like structure favors relevant physiological conditions with chemical and physical gradients as well as cell-cell and cell-extracellular matrix (ECM) interactions that recapitulate many of the hallmarks of cancer in situ. Epidermal growth factor receptor (EGFR) mutations are prevalent in non-small cell lung cancer (NSCLC), yet various mechanisms of acquired resistance, including epithelial-to-mesenchymal transition (EMT), limit the clinical benefit of EGFR tyrosine kinase inhibitors (EGFRi). Improved preclinical models that incorporate the complexity induced by epithelial-to-mesenchymal plasticity (EMP) are urgently needed to advance new therapeutics for clinical NSCLC management. This study was designed to provide a thorough characterization of multicellular spheroids of isogenic cancer cells of various phenotypes and demonstrate proof-of-principle for the applicability of the presented spheroid model to evaluate the impact of cancer cell phenotype in drug screening experiments through high-dimensional and spatially resolved imaging mass cytometry (IMC) analyses. First, we developed and characterized 3D homotypic and heterotypic spheroid models comprising EGFRi-sensitive or EGFRi-resistant NSCLC cells. We observed that the degree of EMT correlated with the spheroid generation efficiency in monocultures. In-depth characterization of the multicellular heterotypic spheroids using immunohistochemistry and high-dimensional single-cell analyses by IMC revealed intrinsic differences between epithelial and mesenchymal-like cancer cells with respect to self-sorting, spatiotemporal organization, and stromal cell interactions when co-cultured with fibroblasts. While the carcinoma cells harboring an epithelial phenotype self-organized into a barrier sheet surrounding the fibroblasts, mesenchymal-like carcinoma cells localized to the central hypoxic and collagen-rich areas of the compact heterotypic spheroids. Further, deep-learning-based single-cell segmentation of IMC images and application of dimensionality reduction algorithms allowed a detailed visualization and multiparametric analysis of marker expression across the different cell subsets. We observed a high level of heterogeneity in the expression of EMT markers in both the carcinoma cell populations and the fibroblasts. Our study supports further application of these models in pre-clinical drug testing combined with complementary high-dimensional single-cell analyses, which in turn can advance our understanding of the impact of cancer-stroma interactions and epithelial phenotypic plasticity on innate and acquired therapy resistance in NSCLC.publishedVersio

Revisiting diagenesis on the Ontong Java Plateau: Evidence for authigenic crust precipitation in Globorotalia tumida

The calcite tests of foraminifera lie in marine sediments for thousands to millions of years, before being analysed to generate trace element and isotope palaeoproxy records. These sediments constitute a distinct physio-chemical environment from the conditions in which the tests formed. Storage in sediments can modify the trace element and isotopic content of foraminiferal calcite through diagenetic alteration, which has the potential to confound their palaeoceanographic interpretation. A previous study of G. tumida from the Ontong Java Plateau, western equatorial Pacific, found that preferential dissolution of higher-Mg chamber calcite, and the preservation of a low-Mg crust on the tests significantly reduced whole-test Mg/Ca and Sr/Ca [Brown and Elderfield, 1996]. Here, we revisit these specimens with a combination of synchrotron X-ray computed tomography (sXCT) and electron probe micro-analyses (EPMA) to re-evaluate the nature of their diagenetic alteration. The dissolution of higher-Mg calcite with depth was directly observed in the sXCT data, confirming the inference of the previous study. The sXCT data further reveal a thickening of the chemically and structurally distinct calcite crust with depth. We propose that these crusts have a diagenetic origin, driven by the simultaneous dissolution of high-Mg chamber calcite and precipitation of low-Mg crust from the resulting modified pore-water solution. While the breadth of the study is limited by the nature of the techniques, the observation of both dissolution and re-precipitation of foraminiferal calcite serves to demonstrate the action of two simultaneous diagenetic alteration processes, with significant impacts on the resulting palaeoproxy signals.The authors would like to acknowledge Aleksey Sadekov, Gerald Langer, India Weidle, Alberto de Fanis, Andrew Bodey, Joan Vila-Comamala and Ulrich Wagner for their help with the project. The work was funded by the Diamond Light Source and by the ERC (2010-NEWLOG ADG-267931 grant to HE).This is the author accepted manuscript. The final version is available from Wiley via http://dx.doi.org/10.1002/2014PA00275