Evolution of the folding ability of proteins through functional selection

An evolutionary process is simulated with a simple spin-glass-like model of proteins to examine the origin of folding ability. At each generation, sequences are randomly mutated and subjected to a simulation of the folding process based on the model. According to the frequency of local configurations at the active sites, sequences are selected and passed to the next generation. After a few hundred generations, a sequence capable of folding globally into a native conformation emerges. Moreover, the selected sequence has a distinct energy minimum and an anisotropic funnel on the energy surface, which are the imperative features for fast folding of proteins. The proposed model reveals that the functional selection on the local configurations leads a sequence to fold globally into a conformation at a faster rate.

Permanence or change? The meaning of genetic variation

Selected aspects of the evolutionary process and more specifically of the genetic variation are considered, with an emphasis in studies performed by my group. One key aspect of evolution seems to be the concomitant occurrence of dichotomic, contradictory (dialect) processes. Genetic variation is structured, and the dynamics of change at one level is not necessarily paralleled by that in another. The pathogenesis-related protein superfamily can be cited as an example in which permanence (the maintenance of certain key genetic features) coexists with change (modifications that led to different functions in different classes of organisms). Relationships between structure and function are exemplified by studies with hemoglobin Porto Alegre. The genetic structure of tribal populations may differ in important aspects from that of industrialized societies. Evolutionary histories also may differ when considered through the investigation of patrilineal or matrilineal lineages. Global evaluations taking into consideration all of these aspects are needed if we really want to understand the meaning of genetic variation.

Evolutionary relationships of the coelacanth, lungfishes, and tetrapods based on the 28S ribosomal RNA gene.

The origin of land vertebrates was one of the major transitions in the history of vertebrates. Yet, despite many studies that are based on either morphology or molecules, the phylogenetic relationships among tetrapods and the other two living groups of lobe-finned fishes, the coelacanth and the lungfishes, are still unresolved and debated. Knowledge of the relationships among these lineages, which originated back in the Devonian, has profound implications for the reconstruction of the evolutionary scenario of the conquest of land. We collected the largest molecular data set on this issue so far, about 3,500 base pairs from seven species of the large 28S nuclear ribosomal gene. All phylogenetic analyses (maximum parsimony, neighbor-joining, and maximum likelihood) point toward the hypothesis that lungfishes and coelacanths form a monophyletic group and are equally closely related to land vertebrates. This evolutionary hypothesis complicates the identification of morphological or physiological preadaptations that might have permitted the common ancestor of tetrapods to colonize land. This is because the reconstruction of its ancestral conditions would be hindered by the difficulty to separate uniquely derived characters from shared derived characters in the coelacanth/lungfish and tetrapod lineages. This molecular phylogeny aids in the reconstruction of morphological evolutionary steps by providing a framework; however, only paleontological evidence can determine the sequence of morphological acquisitions that allowed lobe-finned fishes to colonize land.

Plastisol foaming process. Decomposition of the foaming agent, polymer behavior in the corresponding temperature range and resulting foam properties

The decomposition of azodicarbonamide, used as foaming agent in PVC—plasticizer (1/1) plastisols was studied by DSC. Nineteen different plasticizers, all belonging to the ester family, two being polymeric (polyadipates), were compared. The temperature of maximum decomposition rate (in anisothermal regime at 5 K min−1 scanning rate), ranges between 434 and 452 K. The heat of decomposition ranges between 8.7 and 12.5 J g−1. Some trends of variation of these parameters appear significant and are discussed in terms of solvent (matrix) and viscosity effects on the decomposition reactions. The shear modulus at 1 Hz frequency was determined at the temperature of maximum rate of foaming agent decomposition, and differs significantly from a sample to another. The foam density was determined at ambient temperature and the volume fraction of bubbles was used as criterion to judge the efficiency of the foaming process. The results reveal the existence of an optimal shear modulus of the order of 2 kPa that corresponds roughly to plasticizer molar masses of the order of 450 ± 50 g mol−1. Heavier plasticizers, especially polymeric ones are too difficult to deform. Lighter plasticizers such as diethyl phthalate (DEP) deform too easily and presumably facilitate bubble collapse.

Exploring the research process through the innovation journey of tourism entrepreneurs case study

Presentation for the I International Seminar of Tourism and Hospitality Research, Alicante, April 18th, 2016.

Is there a special kind of "reading" for translation? An empirical investigation of reading in the translation process

The role of reading in translation is rarely discussed in the literature. Translation has mainly been discussed within a product-oriented framework. The more process-oriented approaches of recent years have taken notice of reading as a component activity of the translation process. However, few empirical studies have been completed which address the role of reading in translation. The way a person reads, and the result of that reading (some sort of mental representation of the text or text segment), will depend on the reader's purposes and motivations. The present empirical study indicates that while the translator's reading of a text may be to some extent more thorough and deliberate than that of an ordinary reader, it is not likely to be markedly so. The study also indicates a significant variability in the way translators "read for translation". This suggests the existence of alternate strategies in this kind of reading.

The mechanics of the conform continuous extrusion process

The work describes the programme of activities relating to a mechanical study of the Conform extrusion process. The main objective was to provide a basic understanding of the mechanics of the Conform process with particular emphasis placed on modelling using experimental and theoretical considerations. The experimental equipment used includes a state of the art computer-aided data-logging system and high temperature loadcells (up to 260oC) manufactured from tungsten carbide. Full details of the experimental equipment is presented in sections 3 and 4. A theoretical model is given in Section 5. The model presented is based on the upper bound theorem using a variation of the existing extrusion theories combined with temperature changes in the feed metal across the deformation zone. In addition, constitutive equations used in the model have been generated from existing experimental data. Theoretical and experimental data are presented in tabular form in Section 6. The discussion of results includes a comprehensive graphical presentation of the experimental and theoretical data. The main findings are: (i) the establishment of stress/strain relationships and an energy balance in order to study the factors affecting redundant work, and hence a model suitable for design purposes; (ii) optimisation of the process, by determination of the extrusion pressure for the range of reduction and changes in the extrusion chamber geometry at lower wheel speeds; and (iii) an understanding of the control of the peak temperature reach during extrusion.

A discussion of ethnographic research methods and their relevance for the translation process

In recent years, technologically advanced methodologies such as Translog have gained a lot of ground in translation process research. However, in this paper it will be argued that quantitative research methods can be supplemented by ethnographic qualitative ones so as to enhance our understanding of what underlies the translation process. Although translation studies scholars have sometimes applied an ethnographic approach to the study of translation, this paper offers a different perspective and considers the potential of ethnographic research methods for tapping cognitive and behavioural aspects of the translation process. A number of ethnographic principles are discussed and it is argued that process researchers aiming to understand translators’ perspectives and intentions, how these shape their behaviours, as well as how translators reflect on the situations they face and how they see themselves, would undoubtedly benefit from adopting an ethnographic framework for their studies on translation processes.

On the Poisson Process of Order k Space

2010 Mathematics Subject Classification: 60E05, 62P05.

A kínai reformfolyamat politikai gazdaságtani logikája (The politico-economic logic of the Chinese reform process)

Kína az elmúlt több mint három évtizedben szegény, elmaradott országból a világgazdaság egyik legfontosabb szereplője lett. Szocialista rendszerét egy sajátos kapitalista rendszer váltotta fel, miközben politikai struktúrája lényegében változatlan maradt. A folyamatok során a vezetés mindvégig ügyelt arra, hogy a kommunista párt egyeduralmát semmi se veszélyeztethesse, ugyanakkor megfelelő források álljanak rendelkezésre hatalma megtartásához. A tanulmány a kínai reformfolyamatot politikai gazdaságtani szempontból vizsgálja, különös figyelmet szentelve az intézményi változásoknak. Bemutatja, milyen okok és tényezők álltak a reformok elindításának hátterében, milyen változások következtek be a szereplők érdekviszonyaiban a reformok előrehaladtával, és mire lehet számítani a reformok jövőjét illetően. Úgy tűnik, hogy a jelenlegi rendszer érdekviszonyai a reformok folytatása ellen hatnak, ellehetetlenítve a piacgazdaság intézményrendszerének további kiépítését. A járadékok és privilégiumok az elitet abban sem teszik érdekeltté, hogy komolyabb politikai reformokat hajtson végre, így a kialakuló csapdahelyzet megakadályozza az átmenet kiteljesedését. ____ In the last three decades China has risen from being a poor and underdeveloped country to being one of the most important players in the world economy. Its planned economy has been replaced by a capitalist system, but its political structure has remained essentially unchanged. The leaders during the reform process have sought constantly to avert dangers to the rule of the Communist Party and gain access to valuable resources that allow power to be retained. The study approaches the Chinese reform process from a politico-economic point of view, focusing primarily on institutional changes. It reveals the main factors behind the various phases of reform, the constantly changing interests of the players, and the possible future of the process. It seems that under the current authoritarian regime, there are vested interests working against a continuation of the reforms and precluding full establishment of the institutional framework of a market economy. The elite is also deterred from implementing serious political reforms by the current rents and privileges. This leads to a trap that prevents completion of the transition process.

The recruitment process of the Shining Path and MRTA guerrilla groups: A political psychological perspective

This thesis is an analysis of the recruitment process of the Shining Path -SP- and Revolutionary Movement “Túpac Amaru” -MRTA- guerrilla groups. Although SP was considered more aggressive, it gained more followers than MRTA. This thesis tries to explain why. Social Revolution Theory and Social Movement Theory provide explanations based on issues of “poverty”, disregarding the specific characteristics of the guerrilla groups and their supporters, as well as the influence of specific persuasive processes between the leaders of the groups and their followers. Integrative complexity theory, on the contrary, provides a consistent method to analyze cognitive processes: because people tend to reject complex and sophisticated explanations that require mental efforts, simplicity was the key for success. To prove which guerrilla group provided a simpler worldview, a sample of official documents of SP and MRTA are compared. Finally, content analysis is applied through the Paragraph Completion Test (P.C.T.). ^

History and evolutionary trajectory of the Iranian nuclear program

What actors and processes at what levels of analysis and through what mechanisms have pushed Iran's nuclear program (INP) towards being designated as a proliferation threat (securitization)? What actors and processes at what levels of analysis and through what mechanisms have pushed Iran's nuclear program away from being designated as an existential threat (de-securitization)? What has been the overall balance of power and interaction dynamics of these opposing forces over the last half-century and what is their most likely future trajectory? ^ Iran's nuclear story can be told as the unfolding of constant interaction between state and non-state forces of "nuclear securitization" and "nuclear de-securitization." Tracking the crisscrossing interaction between these different securitizing and de-securitizing actors in a historical context constitutes the central task of this project. ^ A careful tracing of "security events" on different analytical levels reveals the broad contours of the evolutionary trajectory of INP and its possible future path(s). Out of this theoretically conscious historical narrative, one can make informed observations about the overall thrust of INP along the securitization - de-securitization continuum. ^ The main contributions of this work are three fold: First, it brings a fresh theoretical perspective on Iran's proliferation behavior by utilizing the "securitization" theory tracing the initial indications of the threat designation of INP all the way back to the mid 1970s. Second, it gives a solid and thematically grounded historical texture to INP by providing an intimate engagement with the persons, processes, and events of Tehran's nuclear pursuit over half a century. Third, it demonstrates how INP has interacted with and even at times transformed the NPT as the keystone of the non-proliferation regime, and how it has affected and injected urgency to the international discourse on nuclear proliferation specifically in the Middle East.^

Identification of characteristic volatile organic compounds released during the decomposition process of human remains and analogues

The manner in which remains decompose has been and is currently being researched around the world, yet little is still known about the generated scent of death. In fact, it was not until the Casey Anthony trial that research on the odor released from decomposing remains, and the compounds that it is comprised of, was brought to light. The Anthony trial marked the first admission of human decomposition odor as forensic evidence into the court of law; however, it was not "ready for prime time" as the scientific research on the scent of death is still in its infancy. This research employed the use of solid-phase microextraction (SPME) with gas chromatography-mass spectrometry (GC-MS) to identify the volatile organic compounds (VOCs) released from decomposing remains and to assess the impact that different environmental conditions had on the scent of death. Using human cadaver analogues, it was discovered that the environment in which the remains were exposed to dramatically affected the odors released by either modifying the compounds that it was comprised of or by enhancing/hindering the amount that was liberated. In addition, the VOCs released during the different stages of the decomposition process for both human remains and analogues were evaluated. Statistical analysis showed correlations between the stage of decay and the VOCs generated, such that each phase of decomposition was distinguishable based upon the type and abundance of compounds that comprised the odor. This study has provided new insight into the scent of death and the factors that can dramatically affect it, specifically, frozen, aquatic, and soil environments. Moreover, the results revealed that different stages of decomposition were distinguishable based upon the type and total mass of each compound present. Thus, based upon these findings, it is suggested that the training aids that are employed for human remains detection (HRD) canines should 1) be characteristic of remains that have undergone decomposition in different environmental settings, and 2) represent each stage of decay, to ensure that the HRD canines have been trained to the various odors that they are likely to encounter in an operational situation.

Bagasse Fractionation by the Soda Process

The soda process was the first chemical pulping method and was patented in 1845. Soda pulping led to kraft pulping, which involves the combined use of sodium hydroxide and sodium sulfide. Today, kraft pulping dominates the chemical pulping industry. However, about 10% of the total chemical pulp produced in the world is made using non-wood material, such as bagasse and wheat straw. The soda process is the preferred method of chemical pulping of non-wood materials, because it is considered to be economically viable on a small scale and for bagasse is compatible with sugarcane processing. With recent developments, the soda process can be designed to produce minimal effluent discharge and the fouling of evaporators by silica precipitation. The aim of this work is to produce bagasse fibres suitable for papermaking and allied applications and to produce sulfur-free lignin for use in specialty applications. A preliminary economic analysis of the soda process for producing commodity silica, lignin and pulp for papermaking is presented.