1,081 research outputs found
Concept of Sustained Ordering and an ATP-related Mechanism of Lifeβs Origin
This paper shows that the steady state of a system of conjugated reactions, which are characterized by disproportionation of entropy and proceed in the domain of linear interactions, is an attractor of ordering. Such systems are primed to produce ordering, and life is a specific manifestation of the sustained ordering inherent to the chemistry of carbon. The adenosine triphospate (ATP) molecule has properties which makes ATP hydrolysis to be most appropriate to form such a system in primitive world. Hence, ATP is suggested to play a key role in prebiological evolution. Principles of the origin and evolution of life following from the concept of ordering are stated
Death happy: Adaptive ageing and its evolution by kin selection in organisms with colonial ecology
Standard evolutionary theory, supported by mathematical modelling of outbred, dispersed populations predicts that ageing is not an adaptation. We recently argued that in clonal, viscous populations, programmed organismal death could promote fitness through social benefits and has, in some organisms (e.g. Caenorhabditis elegans), evolved to shorten lifespan. Here we review previous adaptive death theory, including consumer sacrifice, biomass sacrifice, and defensive sacrifice types of altruistic adaptive death. In addition we discuss possible adaptive death in semelparous fish, coevolution of reproductive and adaptive death, and adaptive reproductive senescence in C. elegans. We also describe findings from recent tests for the existence of adaptive death in C. elegans using computer modelling. Such models have provided new insights into how trade-offs between fitness at the individual and colony levels mean that senescent changes can be selected traits. Exploring further the relationship between adaptive death and social interactions, we consider examples where adaptive death results more from action of kin than from self-destructive mechanisms and, to describe this, introduce the term adaptive killing of kin.
This article is part of the special issue on βAgeing and socialityβ
Improving procurement autonomous institutions
Π ΡΠΎΠ²ΡΠ΅ΠΌΠ΅Π½Π½ΠΎΠΉ Π ΠΎΡΡΠΈΠΈ Π·Π°ΠΊΡΠΏΠΊΠΈ ΠΊΠ°ΠΊ ΡΡΠ΅Π΄ΡΡΠ²ΠΎ Π²ΠΎΠ·Π΄Π΅ΠΉΡΡΠ²ΠΈΡ Π½Π° ΡΠΊΠΎΠ½ΠΎΠΌΠΈΠΊΡ ΠΈΠΌΠ΅ΡΡ Π±ΠΎΠ»ΡΡΠΎΠ΅ Π·Π½Π°ΡΠ΅Π½ΠΈΠ΅, Π·Π½Π°Π½ΠΈΡ Π² ΠΎΠ±Π»Π°ΡΡΠΈ ΡΠ΅Π³ΡΠ»ΠΈΡΠΎΠ²Π°Π½ΠΈΡ Π·Π°ΠΊΡΠΏΠΎΠΊ, Π° ΡΠ°ΠΊΠΆΠ΅ Π½Π°Π΄Π»Π΅ΠΆΠ°ΡΠ΅ ΠΏΡΠ°Π²ΠΎ ΠΏΡΠΈΠΌΠΈΡΠΈΡΠ΅Π»ΡΠ½Π°Ρ ΠΏΡΠ°ΠΊΡΠΈΠΊΠ° ΠΎΠΊΠ°Π·ΡΠ²Π°Π΅Ρ ΠΏΠΎΠ»ΠΎΠΆΠΈΡΠ΅Π»ΡΠ½ΡΠΉ ΡΡΡΠ΅ΠΊΡ Π½Π° ΡΠ΅ΡΠΎΡΠΌΠΈΡΠΎΠ²Π°Π½ΠΈΠ΅ Π·Π°ΠΊΠΎΠ½ΠΎΠ΄Π°ΡΠ΅Π»ΡΡΡΠ²Π°. ΠΡΠ΅Π΄Π»ΠΎΠΆΠ΅Π½ΠΈΡ ΠΏΠΎ ΡΠΎΠ²Π΅ΡΡΠ΅Π½ΡΡΠ²ΠΎΠ²Π°Π½ΠΈΡ Π·Π°ΠΊΠΎΠ½ΠΎΠ΄Π°ΡΠ΅Π»ΡΡΡΠ²Π°, ΠΏΡΠΎΠ²Π΅ΡΠ΅Π½Ρ Π½Π° ΠΏΡΠ°ΠΊΡΠΈΠΊΠ΅ Π² ΠΈ ΠΌΠΎΠ³ΡΡ Π±ΡΡΡ ΠΈΡΠΏΠΎΠ»ΡΠ·ΠΎΠ²Π°Π½Ρ Π² ΠΏΡΠ°Π²ΠΎΠΏΡΠΈΠΌΠ΅Π½ΠΈΡΠ΅Π»ΡΠ½ΠΎΠΉ ΠΏΡΠ°ΠΊΡΠΈΠΊΠ΅.In modern Russia procurement as a means of influencing the economy are important knowledge in the field of regulation of procurement, as well as the right to properly apologetic practice has a positive effect on the legislative reform. Proposals to improve legislation, tested in practice in Urfa and can be used in law enforcement
When and How Can Death Be an Adaptation?
The concept of phenoptosis (or programmed organismal death) is problematic with respect to most species (including humans) since it implies that dying of old age is an adaptation, which contradicts the established evolutionary theory. But can dying ever be a strategy to promote fitness? Given recent developments in our understanding of the evolution of altruism, particularly kin and multilevel selection theories, it is timely to revisit the possible existence of adaptive death. Here, we discuss how programmed death could be an adaptive trait under certain conditions found in organisms capable of clonal colonial existence, such as the budding yeast Saccharomyces cerevisiae and, perhaps, the nematode Caenorhabditis elegans. The concept of phenoptosis is only tenable if consistent with the evolutionary theory; this accepted, phenoptosis may only occur under special conditions that do not apply to most animal groups (including mammals)
Influence of Heat Treatment Mode of Various Magnesia Rocks on their Properties
Investigations of the changes of structure, specific surface and true density of following high-magnesia rocks at heat treatment have been performed: brucite rocks, magnesite, hydromagnesia rocks, amorphous magnesite. It has been revealed that to obtain chemically active magnesium oxide, which is used for synthesis of high-refractory materials and obtaining magnesia binder, it is necessary to burn at low or moderate temperatures in the temperature range of 500-800 Β°Π‘. Increase of temperature more than 800 Β°Π‘ leads to obtaining densely sintered cubic magnesium oxide with the periclase structure
Enhancing a service life of torch components for MIG/MAG welding
The paper analyzes the main vulnerable elements of torches used in mechanized gas-shielded welding. Particular attention is given to the gas nozzle designs, materials they are made of, and other welding torch elements exposed to increased electrical and thermal stresses during the welding process
Evaluation of simultaneous surgical operations in obesity patients
Aim is to study the quality of life in patients with obesity who underwent hernia repair, in comparison with patients who underwent a weight-correcting intervention. Materials and methods. On the basis of the University Clinic was performed a prospective study of 107 patients with incisional hernia, who underwent a prosthetic hernioplasty and whose BMI exceeded 35 kg/m2. All operated patients were divided into compared groups. The first group consisted of 36 (33.6%) patients who, in addition to hernia correction, underwent one of bariatric procedure. The second group consisted of 71 (66.4%) patients who underwent only prosthetic hernioplasty. In this groups was assessed the quality of life by SF-36 questionnaire before and 1 year after the operation. Results and discussion. It was found a correlation between the weight-correction surgery with the physical component of health, indicating a decrease in the role of physical problems in limiting the patient's life. Significant differences were revealed on the scales of physical functioning, health assessment, and the physical component of quality of life. Conclusion. Performing a simultaneous bariatric surgery with hernia repair improves the quality of life in these patients
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