1,759 research outputs found
Ageing as a price of cooperation and complexity: Self-organization of complex systems causes the ageing of constituent networks
The analysis of network topology and dynamics is increasingly used for the description of the structure, function and evolution of complex systems. Here we summarize key aspects of the evolvability and robustness of the hierarchical network-set of macromolecules, cells, organisms, and ecosystems. Listing the costs and benefits of cooperation as a necessary behaviour to build this network hierarchy, we outline the major hypothesis of the paper: the emergence of hierarchical complexity needs cooperation leading to the ageing of the constituent networks. Local cooperation in a stable environment may lead to over-optimization developing an ‘always-old’ network, which ages slowly, and dies in an apoptosis-like process. Global cooperation by exploring a rapidly changing environment may cause an occasional over-perturbation exhausting system-resources, causing rapid degradation, ageing and death of an otherwise ‘forever-young’ network in a necrosis-like process. Giving a number of examples we explain how local and global cooperation can both evoke and help successful ageing. Finally, we show how various forms of cooperation and consequent ageing emerge as key elements in all major steps of evolution from the formation of protocells to the establishment of the globalized, modern human society. Thus, ageing emerges as a price of complexity, which is going hand-in-hand with cooperation enhancing each other in a successful community
Use of r(+)-n-propargyl-1-aminoindan to treat or prevent hearing loss
A method of treating or inhibiting hearing loss in a mammalian subject, comprising administering to the subject an amount of R(+)-N-propargyl-1-aminoindan or pharmaceutically acceptable salt thereof effective to treat or inhibit the hearing loss in the subject
Pretkoncentracija mikroelemenata iz vode koristeći 4-morfolin ditiokarbamat
The optimum conditions were found for the preconcentration of trace metals in natural waters and model samples with standard metals concentrations by using 4-morpholine dithiocarbamate. The formed complexes were extracted with chloroform. Different methods for recovering the metals from the organic solvent were studied and compared before AAS metal analysis. The developed preconcentration method was successfully applied to the determination of trace metals concentrations in water samples from the "Barje" lake (Leskovac. Yugoslavia).Nađeni su optimalni uslovi za pretkoncentraciju mikroelemenata iz vode koristeći 4-morfolin ditiokarbamat kao kompleksirajući agens. Nagrađeni kompleksi su ekstrahovani hloroformom. Upoređeni su različiti načini ekstrakcije metalnih jona iz organskog rastvarača pre analize atomskom apsorpcionom spektrofotometrijom. Razvijena metoda za pretkoncentraciju uspešno je primenjena za analizu uzoraka vode jezera Barje (Leskovac Jugoslavija)
On the Thermal Activation of Negative Bias Temperature Instability
The temperature dependence of negative bias temperature instability (NBTI) is investigated on 2.0nm SiO2 devices from temperatures ranging from 300K down to 6K with a measurement window of ~12ms to 100s. Results indicate that classic NBTI degradation is observed down to ~200K and rarely observed at temperatures below 140K in the experimental window. Since experimental results show the charge trapping component contributing to NBTI is thermally activated, the results cannot be explained with the conventionally employed elastic tunneling theory. A new mechanism is observed at temperatures below 200K where device performance during stress conditions improves rather than degrades with time, which is opposite to the classical NBTI phenomenon
(S,S)-N,N '-Bis(1-carboxy-2-methylpropyl)ethylenediammonium dihalide cyclopentanol tetrasolvate (halide = bromide/chloride similar or equal to 1:12)
In the crystal structure of the title compound, C(12)H(26)N(2)O(4)(2+)center dot-2(Br(0.085)Cl(0.915))(-)center dot 4C(5)H(9)OH, the complete cation is generated by crystallographic twofold symmetry. Contamination of the chloride counter-anion with bromide occured during the preparation, due to the use of 1,2-dibromoethane. One of the solvent molecules is disordered, with occupancies 0.53 (3): 0.47 (3). The crystal packing is stabilized by an infinite two dimensional center dot center dot center dot X center dot center dot center dot H-N-H center dot center dot center dot X center dot center dot center dot hydrogen-bonding network (X: Br(-)/Cl(-) similar or equal to 1:12). In addition, O-H center dot center dot center dot X and O-H center dot center dot center dot O hydrogen bonds involving solvent molecules are observed
Bacterial Peritonitis Following Esophagogastroduodenoscopy in a Patient on Peritoneal Dialysis
Effect of Exhaust Pressure on the Performance of an 18-cylinder Air-cooled Radial Engine with a Valve Overlap of 40 Degrees
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