Building blocks of a fish head: Developmental and variational modularity in a complex system

2015 ◽  
Vol 324 (7) ◽  
pp. 614-628 ◽  
Author(s):  
Caroline Lehoux ◽  
Richard Cloutier
Keyword(s):  
Complex System ◽  
Building Blocks ◽  
Variational Modularity

Ligand-Dependent Regiodivergent Enantioselective Allylic Alkylations of α-Trifluoromethylated Ketones

2020 ◽  
Author(s):  
Yi Zhu ◽  
Yifan Ni ◽  
Chenxi Lu ◽  
Xiaochen Wang ◽  
Yi Wang ◽  
...  
Keyword(s):  
Complex System ◽  
Medicinal Chemistry ◽  
Palladium Complex ◽  
Transition States ◽  
Building Blocks ◽  
Computational Studies ◽  
Allylic Alkylations ◽  
Pharmacokinetic Properties ◽  
Metabolic Degradation ◽  
Enantioselective Addition

Abstract The asymmetric introduction of CF3 unit is a powerful tool for modifying pharmacokinetic properties and slowing metabolic degradation in medicinal chemistry. A catalytic and enantioselective addition of α-CF3 enolates allows for expeditious access to functionalized chiral building blocks with CF3-containing stereogenicity. The computational studies reveal that the choice of ligand in a designed palladium-complex system regulates the regioselectivity and stereoselectivity of the asymmetric allylic alkyation (AAA) of α-CF3 ketones and Morita–Baylis–Hillman (MBH) adducts. Multiple C-H···F interactions are involved in the transition states.

scholarly journals The Building Blocks of Social Trust: The Role of Customary Mechanisms and Property Relations for the Emergence of Social Trust in the Context of the Commons

2021 ◽  
pp. 004839312110084
Author(s):  
Marc Goetzmann
Keyword(s):  
Complex System ◽  
Social Trust ◽  
Building Blocks ◽  
Institutional Structure ◽  
External Effects ◽  
Property Relations ◽  
Management Of Resources ◽  
Mutual Monitoring ◽  
The Commons

This paper argues that social trust is the emergent product of a complex system of property relations, backed up by a sub-system of mutual monitoring. This happens in a context similar to Ostrom’s commons, where cooperation is necessary for the management of resources, in the absence of external authorities to enforce sanctions. I show that social trust emerges in this context because of an institutional structure that enables individuals to develop a generalized disposition to internalize the external effects of their actions. This is made possible by the “patrimonial” nature of this structure.

scholarly journals Formal verification with HiLLS-specified models: A further step in multi-analysis modeling of complex systems

2019 ◽  
Vol 10 (05) ◽  
pp. 1950032 ◽  
Author(s):  
Kehinde G. Samuel ◽  
Oumar Maiga ◽  
Mamadou K. Traoré
Keyword(s):  
Complex System ◽  
Formal Verification ◽  
Discrete Event Simulation ◽  
Discrete Event ◽  
Building Blocks ◽  
High Level Language ◽  
Graphical Language ◽  
Event Simulation ◽  
Unique Model ◽  
High Level

The multi-analysis modeling of a complex system is the act of building a family of models which allows to cover a large spectrum of analysis methods (such as simulation, formal methods, enactment,[Formula: see text]) that can be performed to derive various properties of this system. The High-Level Language for Systems Specification (HiLLS) has recently been introduced as a graphical language for discrete event simulation, with potential for other types of analysis, like enactment for rapid system prototyping. HiLLS defines an automata language that also opens the way to formal verification. This paper provides the building blocks for such a feature. That way, a unique model can be used not only to perform both simulation and enactment experiments but also to allow the logical analysis of properties without running any experiment. Therefore, it saves from the effort of building three different analysis-specific models and the need to align them semantically.

Photochemical Evolution of Interstellar/Precometary Organic Material

1997 ◽  
Vol 161 ◽  
pp. 23-47 ◽  
Author(s):  
Louis J. Allamandola ◽  
Max P. Bernstein ◽  
Scott A. Sandford
Keyword(s):  
Origin Of Life ◽  
Building Blocks ◽  
Complex Species ◽  
Infrared Observations ◽  
Interstellar Ice ◽  
Polycyclic Aromatic ◽  
Ultraviolet Photolysis ◽  
The Origin Of Life ◽  
Simple Molecules ◽  
Complex Organic

AbstractInfrared observations, combined with realistic laboratory simulations, have revolutionized our understanding of interstellar ice and dust, the building blocks of comets. Since comets are thought to be a major source of the volatiles on the primative earth, their organic inventory is of central importance to questions concerning the origin of life. Ices in molecular clouds contain the very simple molecules H2O, CH3OH, CO, CO2, CH4, H2, and probably some NH3and H2CO, as well as more complex species including nitriles, ketones, and esters. The evidence for these, as well as carbonrich materials such as polycyclic aromatic hydrocarbons (PAHs), microdiamonds, and amorphous carbon is briefly reviewed. This is followed by a detailed summary of interstellar/precometary ice photochemical evolution based on laboratory studies of realistic polar ice analogs. Ultraviolet photolysis of these ices produces H2, H2CO, CO2, CO, CH4, HCO, and the moderately complex organic molecules: CH3CH2OH (ethanol), HC(= O)NH2(formamide), CH3C(= O)NH2(acetamide), R-CN (nitriles), and hexamethylenetetramine (HMT, C6H12N4), as well as more complex species including polyoxymethylene and related species (POMs), amides, and ketones. The ready formation of these organic species from simple starting mixtures, the ice chemistry that ensues when these ices are mildly warmed, plus the observation that the more complex refractory photoproducts show lipid-like behavior and readily self organize into droplets upon exposure to liquid water suggest that comets may have played an important role in the origin of life.

A Reproducible Selective Stain for Cardiac Sarcoplasmic Reticulum

1974 ◽  
Vol 32 ◽  
pp. 214-215
Author(s):  
R. A. Waugh ◽  
J. R. Sommer
Keyword(s):  
Complex System ◽  
Electron Microscope ◽  
Sarcoplasmic Reticulum ◽  
Transmission Electron Microscope ◽  
Electron Microscopic ◽  
Cardiac Sarcoplasmic Reticulum ◽  
Transmission Electron

Cardiac sarcoplasmic reticulum (SR) is a complex system of intracellular tubules that, due to their small size and juxtaposition to such electron-dense structures as mitochondria and myofibrils, are often inconspicuous in conventionally prepared electron microscopic material. This study reports a method with which the SR is selectively “stained” which facilitates visualizationwith the transmission electron microscope.

Laboratory and in-situ analysis of comet dust

1988 ◽  
Vol 46 ◽  
pp. 8-9
Author(s):  
D.E. Brownlee ◽  
A.L. Albee
Keyword(s):  
Electron Microscopy ◽  
Solar System ◽  
Laboratory Study ◽  
Isotopic Analysis ◽  
Building Blocks ◽  
Sem Analysis ◽  
Early Solar System ◽  
Cometary Material ◽  
Comet Dust

Comets are primitive, kilometer-sized bodies that formed in the outer regions of the solar system. Composed of ice and dust, comets are generally believed to be relic building blocks of the outer solar system that have been preserved at cryogenic temperatures since the formation of the Sun and planets. The analysis of cometary material is particularly important because the properties of cometary material provide direct information on the processes and environments that formed and influenced solid matter both in the early solar system and in the interstellar environments that preceded it.The first direct analyses of proven comet dust were made during the Soviet and European spacecraft encounters with Comet Halley in 1986. These missions carried time-of-flight mass spectrometers that measured mass spectra of individual micron and smaller particles. The Halley measurements were semi-quantitative but they showed that comet dust is a complex fine-grained mixture of silicates and organic material. A full understanding of comet dust will require detailed morphological, mineralogical, elemental and isotopic analysis at the finest possible scale. Electron microscopy and related microbeam techniques will play key roles in the analysis. The present and future of electron microscopy of comet samples involves laboratory study of micrometeorites collected in the stratosphere, in-situ SEM analysis of particles collected at a comet and laboratory study of samples collected from a comet and returned to the Earth for detailed study.

Cryo-TEM of amphiphilic polymer and amphiphile/polymer solutions

1993 ◽  
Vol 51 ◽  
pp. 876-877
Author(s):  
Yeshayahu Talmon
Keyword(s):  
Microstructural Characterization ◽  
Building Blocks ◽  
Quantitative Information ◽  
Physical Models ◽  
Specimen Preparation ◽  
Time Resolved ◽  
Temperature Changes ◽  
Temperature And Humidity ◽  
Microstructured Fluids ◽  
Air Streams

To achieve complete microstructural characterization of self-aggregating systems, one needs direct images in addition to quantitative information from non-imaging, e.g., scattering or Theological measurements, techniques. Cryo-TEM enables us to image fluid microstructures at better than one nanometer resolution, with minimal specimen preparation artifacts. Direct images are used to determine the “building blocks” of the fluid microstructure; these are used to build reliable physical models with which quantitative information from techniques such as small-angle x-ray or neutron scattering can be analyzed.To prepare vitrified specimens of microstructured fluids, we have developed the Controlled Environment Vitrification System (CEVS), that enables us to prepare samples under controlled temperature and humidity conditions, thus minimizing microstructural rearrangement due to volatile evaporation or temperature changes. The CEVS may be used to trigger on-the-grid processes to induce formation of new phases, or to study intermediate, transient structures during change of phase (“time-resolved cryo-TEM”). Recently we have developed a new CEVS, where temperature and humidity are controlled by continuous flow of a mixture of humidified and dry air streams.

Emotional Variability Predicts Tiredness in Daily Life

2016 ◽  
Vol 37 (3) ◽  
pp. 181-193 ◽  
Author(s):  
Aire Mill ◽  
Anu Realo ◽  
Jüri Allik
Keyword(s):  
Sampling Method ◽  
Daily Life ◽  
Emotional Experience ◽  
Experience Sampling ◽  
Experience Sampling Method ◽  
Building Blocks ◽  
Intraindividual Variability ◽  
Unique Role ◽  
Over Time

Abstract. Intraindividual variability, along with the more frequently studied between-person variability, has been argued to be one of the basic building blocks of emotional experience. The aim of the current study is to examine whether intraindividual variability in affect predicts tiredness in daily life. Intraindividual variability in affect was studied with the experience sampling method in a group of 110 participants (aged between 19 and 84 years) during 14 consecutive days on seven randomly determined occasions per day. The results suggest that affect variability is a stable construct over time and situations. Our findings also demonstrate that intraindividual variability in affect has a unique role in predicting increased levels of tiredness at the momentary level as well at the level of individuals.

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