Miracle-dz/UniFAR-FTUs huggingface dataset:
O estabelecimento da cooperação no contexto das estratégias reativas

Diversas especies na natureza exibem comportamento cooperativo. O chamado dilema do prisioneiro e um jogo amplamente estudado para modelar o fenomeno da emergencia da cooperacao. Nesse jogo, os individuos tem duas opcoes: cooperar (C) ou desertar (D), que e o comportamento nao cooperativo. Se o jogo e composto de uma unica rodada, a desercao e a melhor opcao, visto que ela fornece um ganho maior para o jogador. Porem, uma vez que individuos se encontram e jogam varias vezes entre si, a cooperacao pode emergir. Se p e q sao, respectivamente, as probabilidades do jogador cooperar dado que o seu oponente tenha cooperado e desertado na rodada anterior, uma infinidade de estrategias e permitida. A evolucao temporal das frequencias dos individuos que jogam uma estrategia e ditada pela equacao do replicador. Como existem versoes diferentes para essa equacao e formas diferentes de resolve-la numericamente (usando abordagens computacionais para se resolver equacoes continuas e discretas), resultados diferentes podem ser obtidos. Neste trabalho foi mostrado que os resultados da literatura (a vitoria da estrategia \tit-for-tat"generosa) e encontrado somente sob condicoes especificas. Um argumento analitico envolvendo analises de equilibrio de Nash foi construi a fim de confirmar os resultados. Para investigar o estabelecimento da cooperacao, as solucoes numericas foram obtidas usando-se as versoes continua e discreta das duas formas da equacao do replicador (forma de Taylor e forma de Maynard Smith). Basicamente, a cooperacao so e capaz de se manter se a densidade de estrategias presente no jogo nao e muito grande.
Cytotoxicity of chlopyrifos and cypermethrin: The ameliorative effects of antioxidants

The present paper reviews the mechanism underlying chlorpyrifos and cypermethrin poisoning. It explains the mechanism of action of chlopyrifos and cypermethrin and the role of oxidative stress. It sheds light on the interaction between chlopyrifos and cypermethrin as observed in many cocktails of pesticide combinations today. It also explains the adverse health effects of pesticides and some antioxidants which may ameliorate their effects. Further research aimed at identifying more agents that may ameliorate chlorpyrifos and cypermethrin-induced toxicity should be carried out. Key words : Pesticides, chlorpyrifos, cypermethrin oxidative stress, antioxidant.
Ionic basis for variability in repolarisaion and its implications in pathological response

Sudden cardiac death represents one of the leading causes of death worldwide, with the majority of these deaths caused by arrhythmias derived from ischæmic events. However, the mechanisms leading from ischæmia to re-entry, arrhythmia and eventual death are poorly understood. Furthermore, variability in the action potential of cardiac tissue, while important in determining arrhythmic risk, is only recently being addressed in computational modelling, with little known about the causes and mechanisms underlying it, nor regarding its evolution in response to pathological conditions such as ischæmia. This dissertation investigates the causes of variability in the repolarisation of the action potential of the rabbit ventricular myocyte, and the response of this variability to ischæmia. The effect of variability in ion channel conductances is investigated by means of a complete search of the parameter space revealed by simultaneous variation in multiple parameters describing ion channel conductances in computational models of the rabbit ventricular action potential. Rabbit data and models are used in this thesis due to the similarities to human data, both in terms of electrophysiology generally, and the response to ischæmia specifically. The response of two different model frameworks is assessed to determine similarities and differences between model frameworks that are designed to reproduce the same system. Those models producing action potential durations that fall within an experimentally derived range at multiple pacing rates are used to define model populations that thus reproduce experimental variability in repolarisation. Thesemodel populations are used to investigate the effects of ischæmic conditions on population variability. Variability is measured not only for action potential duration, but also for other biomarkers commonly implicated in the development of re-entry. The work presented in this dissertation is significant for: (1) presenting a comprehensive study of the effect of simultaneous variation in ion channel conductances, with details regarding the interactions between conductances and how these interactions change depending on the pacing rate; (2) detailed examination of the differences between two models of the same system; (3) production of the largest extant populations reproducing experimentally observed variability in action potential duration; (4) the first time model populations have been used to investigate the effects of ischæmia on variability.
Role and Regulation of Starch Phosphorylase and Starch Synthase IV in Starch Biosynthesis in Maize Endosperm Amyloplasts

ROLE AND REGULATION OF PLASTIDIAL STARCH PHOSPHORYLASE AND STARCH SYNTHASE IV IN STARCH BIOSYNTHESIS IN MAIZE ENDOSPERM AMYLOPLASTS Renuka M. Subasinghe Advisor: University of Guelph, 2013 Dr. Ian Tetlow Storage starch is synthesized in sub-cellular organelles called amyloplasts in higher plants. The synthesis of the starch granule is a result of the coordinated activity of several groups of starch biosynthetic enzymes. There are four major groups of these enzymes, ADP-glucose pyrophosphorylase (AGPase), starch synthases (SS), starch branching enzymes (SBE), and starch debranching enzymes (SDE). Starch phosphorylase (SP) exists as both dimeric and tetrameric forms in plastids in developing cereal endosperm and catalyses the reversible transfer of glucosyl units from glucose-1-phosphate to the nonreducing end of α-1-4 linked glucan chains, although the precise role in the pathway remains unclear. The present study was conducted to investigate the role and regulation of SP and SSIV in starch biosynthesis in developing maize endosperm. The results of this study showed that the tetrameric form of SP accounts for the majority of measurable catalytic activity, with the dimeric form being barely active and the monomer catalytically inactive. A catalytically active recombinant maize SP was heterologously expressed and used as an affinity ligand with amyloplast lysates to test protein-protein interactions in vitro. Results showed that the different multimeric status of SP influenced interactions with other enzymes of starch synthesis. Tetrameric SP interacted with SBEI and SSIIa, whilst the dimeric form of the enzyme interacted with SBEI, SBEIIb. All of these interactions were enhanced when amyloplasts were pre-treated with ATP, and broken following treatment with alkaline phosphatase (APase), indicating these interactions are regulated by protein phosphorylation. In addition, the catalytic activity of SSIV was reduced following treatment with APase, indicating a role for protein phosphorylation in the regulation of SSIV activity. Proteinprotein interaction experiments also suggested a weak interaction between SSIV and SP. Multimeric forms of SP regulated by protein-protein interactions and protein phosphorylation suggested a role for SP in starch biosynthesis in maize endosperm.
Adrenergic protection of the fish heart under simulated exercise conditions

Exercise is an integral part of the survival of vertebrates. However, intense exercise disrupts extracellular homeostasis, resulting in venous blood becoming hypoxic, hyperkalemic and acidotic. These changes challenge the heart, as the venous blood passing through the ventricular lumen is the sole source of myocardial support for most vertebrates. Consequently, during exercise when the heart is working its hardest it must ironically be supported by the hostile composition of venous blood. Rainbow trout (Oncorhynchus mykiss) and African catfish (Claris gariepinus) were used to examine the role of adrenergic stimulation in protecting cardiac performance during exercise-induced changes in venous blood composition. As cardiac performance is ultimately limited by oxygen supply, in situ perfused rainbow trout hearts were first used to determine the effect of adrenergic stimulation on the venous hypoxic threshold during simulated exercise conditions (5.0 m M K + , p H 7.5); where the hypoxic threshold is defined as the lowest level of venous oxygen tension (PVO2) that can support maximum cardiac performance. Hearts were tested under these relevant conditions with both tonic (5 n M adrenaline, A D ) and maximal (500 n M A D ) adrenergic stimulation. With 5 n M A D maximum cardiac performance in hearts at 10°C was significantly reduced even at normoxia. In contrast, 500 n M A D fully protected cardiac performance under hyperkalemia and acidosis to hypoxia of 2.0 kPa, a Pvc-2 close to routine values in vivo. Temperature acclimation alters the response of the rainbow trout heart to adrenaline such that an increase in acclimation temperature is associated with a decrease in adrenergic sensitivity. To determine how this reduction in adrenergic effectiveness alters the protection
Effect of rumen escape amino acids andmultiple TBA implants on feedlot performanceof lightweight Holstein steer calves

Two hundred forty Holstein steers (343 lb) were stratified by weight and allotted to one of eight treatment combinations in a 2 x 4 factorial arrangement. Main effects were implant (Synovex-S (S) or Synovex-S + Finaplix-S (SF) on day 0, 87, 168, and 238 and level of rumen escape amino acids (Smartamine-ML (SML) at 0, 5, 10, or 15 grams/head/day). These levels of SML supplied 0, 2.75, 5.5, and 8.25 g/day of Llysine and 0, . 75, 1.5, and 2.25 g/day of DL-methionine. Steers implanted with SF gained 4% faster, had a 4% improvement in feed:gain, a lower dressing percentage, 12% less backfat, 3.4% more rib-eye area, a lower yield grade, less marbling, and fewer Choice grades (P<.05) compared to S-implanted steers. Overall feed intake and carcass weights were similar between Sand SF-implanted steers. Use of SML resulted in a linear decline in hot carcass weight (P<.10) and KPH (P<.05), with other carcass traits unaffected. Increasing the level of SML tended to increase feed intake (P<.15), and quadratically degraded feed:gain (P<.10). Repeated implants of SF did not improve carcass worth and the use of rumen escape amino acids did not improve performance, suggesting that the basal diet was not first-limiting in lysine and(or) methionine.
CLIMATIC WARMING, SPRING BUDBURST AND FROST DAMAGE ON TREES

SUMMARY (1) If future C02-induced warming of 2 'C increased the incidence of warm springs, of the type that have occurred in Britain during this century, then warming would induce earlier blossoming and budburst in many temperate trees, with an increase in the risk of subsequent damaging frosts. There would, for example, be an increase in the already high incidence of frost damage to apple blossom (Malus pumila Mill.) cv. Cox's Orange Pippin, in Kent and to new vegetative shoots of Picea sitchensis (Bong.) Carr. in the Scottish uplands. (2) If budburst occurred after a constant thermal time (e.g. 100 day 'C > 5 0C after mid-January), then budburst would occur so much earlier in the spring that, on average, the temperature on the date of budburst would be lower than at present. Consequently, the risk of damaging frosts occurring after budburst would be much increased. (3) However, in many trees there is an increase in the thermal time to budburst with decreased chilling. This increase prevents very early budburst in warm springs, and lessens the risk of frost damage. (4) Theoretically, warming could delay or advance budburst, depending upon the extent to which a tree's chilling requirements are currently met. (5) Empirical thermal time-chilling models suggested that, on average, Cox's apple in Kent would blossom 18-24 days earlier than at present following 2 'C warming, but that P. sitchensis in the Scottish uplands would burst its buds only 5 days earlier than at present.
Les radicaux libres dans l'organisme des animaux d'élevage: conséquences sur la reproduction, la physiologie et la qualité de leurs produits

Les radicaux libres sont des composes caracterises par une structure electronique desequilibree qui leur confere une grande reactivite sur les constituants organiques et sur les structures cellulaires.Ils se forment de facon inevitable en parallele au metabolisme energetique et par une multitude d'autres voies. Ils favorisent habituellement le bon fonctionnement de l'organisme et la sante des mammiferes, mais leur exces peut etre nefaste. En dehors de toute situation pathologique, leur production est stimulee par toute situation de stress, en particulier par la manipulation maladroite ou brutale des animaux, par l'exercice physique, par le froid, par des niveaux d'alimentation excessifs ou par des desequilibres alimentaires. Elle peut alors atteindre des niveaux nuisibles pour les aspects quantitatifs et qualitatifs des productions animales.
Variation in dinosaur skeletochronology indicators: implications for age assessment and physiology

Twelve different bones from the skeleton of the holotype specimen of the hadrosaurian dinosaur Hypacrosaurus stebingeri were thin-sectioned to evaluate the significance of lines of arrested growth (LAGs) in age assessments. The presence of an external fundamental system (EFS) at the external surface of the cortex and mature epiphyses indicate that the Hypacrosaurus specimen had reached adulthood and growth had slowed considerably from earlier stages. The number of LAGs varied from none in the pedal phalanx to as many as eight in the tibia and femur. Most elements had experienced considerable Haversian reconstruction that had most likely obliterated many LAGs. The tibia was found to have experienced the least amount of reconstruction, but was still not optimal for skeletochronology because the LAGs were difficult to count near the periosteal surface. Additionally, the numbers of LAGs within the EFS vary considerably around the circumference of a single element and among elements. Counting LAGs from a single bone to assess skeletochronology appears to be unreliable, particularly when a fundamental system exists. Because LAGs are plesiomorphic for tetrapods, and because they are present in over a dozen orders of mammals, they have no particular physiological meaning that can be generalized to particular amniote groups without independent physiological evidence. Descriptions of dinosaur physiology as “intermediate” between the physiology of living reptiles and that of living birds and mammals may or may not be valid, but cannot be based reliably on the presence of LAGs.
Specific Primers for Rapid and Sensitive Identification of Vibrio vulnificus

A primer pair designed from vvbfp (Vibrio vulnificus blue fluorescent protein) of V. vulnificus amplified a 251 bp PCR fragment from all clinical isolates of V. vulnificus and failed to amplify any fragment from other clinical pathogens. The sensitivity of the primer pair is as little as 1 fg of chromosomal DNA and 60 cells of V. vulnificus. In a scientific evaluation of specimens, a total of 22 samples including serum specimens and wound aspirates from septicemic mice were screened by PCR. Thirteen (92.9%) of the 14 V. vulnificus culture-positive specimens gave positive results. Three (37.5%) of the 8 culturenegative specimens yielded positive results. The primer set gives high sensitivity and specificity in a one-step PCR protocol, an important criterion for unambiguous bacterial identification.
Microsatellite-enriched libraries : applied methodology for the development of SSR markers in tropical crops

Introduction. Les productions tropicales, primordiales pour les pays en voie de developpement, peuvent cependant etre considerees comme le parent pauvre des marqueurs moleculaires. L'utilisation des marqueurs microsatellites a de nombreux avantages par rapport a d'autres techniques moleculaires comme les analyses d'isozymes, de RFLP ou de RADP. Notre objectif a donc ete de developper une methode permettant de constituer des banques enrichies en microsatellites en utilisant, comme materiel de depart, de l'ADN de plantes tropicales. Une construction simple et rapide de banque enrichie en sequences microsatellites (GA) n du palmier a huile est decrite ici. Procedure de construction de banques enrichies en microsatellites. L'hybridation avec une sonde microsatellite biotinylee puis la capture des sequences ciblees grâce a des particules magnetiques recouvertes de streptavidine sont les deux principes de la technique utilisee. Les differentes etapes de la methode sont discutees et un protocole optimise est propose. Caracterisation des banques enrichies. Les banques de plusieurs milliers de clones ont une proportion de clones positifs, contenant un microsatellite, superieure a 70 %. Le taux de redondance des clones positifs depend du mode de preparation de l'ADN, avec, respectivement, 20 et 60 % pour des fragments obtenus par restriction par PstI ou par sonication. Conclusion. L'etude presentee donne une technique pour developper facilement des banques de marqueurs microsatellites specifiques des plantes tropicales en attendant que la communaute internationale entreprenne des projets moleculaires appliques a l'amelioration genetique de ces cultures traditionnellement oubliees.
Integrated high-resolution physical and comparative gene maps in horses

Integrated High-Resolution Physical and Comparative Gene Maps in Horses. (December 2006) Candice Lea Brinkmeyer Langford, B.S., Texas A&M University Chair of Advisory Committee: Dr. Bhanu Chowdhary High-resolution physically ordered gene maps for the horse (Equus caballus, ECA) are essential to the identification of genes associated with hereditary diseases and traits of interest like fertility, coat color, and disease resistance or susceptibility. Such maps also serve as foundations for genome comparisons across species and form the basis to study chromosome evolution. In this study seven equine chromosomes (ECA6, 7, 10, 15, 18, 21 and X) corresponding to human chromosomes (HSA) 2, 19 and X were selected for high-resolution mapping on the basis of their potential involvement in diseases and conditions of importance to horses. To accomplish this, geneand sequence-specific markers were generated and genotyped on the TAMU 5000rad horse x hamster RH panel. Additionally, screening of a BAC library by overgoes and subsequent STS content mapping and fingerprinting approaches were used to assemble and verify a BAC contig along a ~5 Mb span on ECA21. Dense gene maps were generated for each of the seven equine chromosomes by adding 408 new markers (285 type I and 123 type II) to the current maps of these chromosomes, thereby greatly improving overall map resolution to one mapped marker every 960kb on average (range: 700 kb – 1.3 Mb). Moreover, the contig on ECA21
The cyclic-di-GMP receptors of S. Typhimurium: Testing their signaling specificity through second messenger affinity and their use as biosensors

The cyclic-di-GMP receptors of S. Typhmurium: testing their signaling specificity through second messenger affinity and their use as biosensors Ingrid Swanson Pultz Chair of the Supervisory Committee: Professor Samuel I. Miller Department of Microbiology c-di-GMP is a second messenger that regulates motility and the production of adhesive factors in many bacterial species. Enzymes containing specific c-di-GMP metabolizing domains integrate information about the environment into an intracellular level of c-di-GMP that then binds to specific downstream receptors, including proteins that contain the PilZ domain. Many bacterial species encode dozens of c-di-GMP metabolizing enzymes in their genomes. Although each of these enzymes metabolizes the same small, diffusible second messenger molecule, many of these proteins can be specifically linked to downstream c-di-GMP-regulated processes. The mechanisms involved in achieving this signaling specificity between c-di-GMP metabolizing enzymes and their downstream receptors are not known. Here, we provide evidence that c-diGMP signaling specificity is achieved through differences in the binding affinities of downstream receptors. Salmonella Typhimurium harbors two PilZ domain proteins: YcgR, which controls flagellar-based motility, and BcsA, an enzyme that produces cellulose. Using a Forster resonance energy transfer (FRET)-based method, we measured the binding affinities of these PilZ domain proteins and found that they span a 43-fold range. Increasing the binding affinity of BcsA for c-di-GMP increased the amount of cellulose that this enzyme produced at lower levels of c-di-GMP. Decreasing the affinity of YcgR for c-di-GMP increased the amount of this second messenger needed for YcgR to inhibit motility. In addition, we found that mutation in yhjH, which encodes a predicted c-di-GMP-degrading enzyme, increased the fraction of the cellular population that demonstrated c-di-GMP levels high enough to bind to the higheraffinity YcgR protein, but did not enough to bind to the lower-affinity BcsA protein and stimulate cellulose production. Thus, the specific affinities of these proteins for c-di-GMP are important for their biological functions. Additionally, the binding affinities of the eight PilZ domain proteins in Pseudomonas aeruginosa were measured and found to span a 145-fold range, implying that regulation by binding affinity of downstream receptors for c-di-GMP may be a common theme in c-di-GMP signaling. Finally, we generated a panel of FRET-based c-di-GMP biosensors which will allow for the accurate measurement of the free c-di-GMP level in individual cells from the nanomolar to the micromolar range.
A gall mite, Aceria rhodiolae (Acari: Eriophyidae), altering the phytochemistry of a medicinal plant, Rhodiola rosea (Crassulaceae), in the Canadian Arctic

ABSTRACT The eriophyid mite Aceria rhodiolae (G. Canestrini) is known to induce galls on the flowers and leaves of roseroot, Rhodiola rosea L. , in subarctic and alpine regions of Europe. After discovering galls on the inflorescences of roseroot in Nunavik (Québec), northeastern Canada, we examined the mites extracted from the galls and compared them with specimens of A. rhodiolae from Europe. Through morphological analyses, we demonstrate that the mites from galls in Nunavik are conspecific with A. rhodiolae from Europe. We then provide a detailed redescription of the mite species based on the morphology of adult females and males from Canada and Europe, using a combination of standard light microscopy, confocal microscopy and scanning electron microscopy. Because roseroot is well-known for its medicinal properties, we tested the hypothesis that roseroot galled by the mite had altered phytochemistry, by using salidroside and rosavins as indicators. Our results show a significant reduction of almost half in salidroside content (45.8%), but not in rosavins. Moreover, because the mite sometimes affects most or all of the inflorescence of R. rosea, it can considerably reduce the production of seeds. We also show that A. rhodiolae is widespread along the Ungava Bay (Nunavik), with 31.5% of 92 sites surveyed having at least a few to numerous plants galled. Given the importance of roseroot as a crop for Inuit communities and as medicinal products used by them and other Canadians, and also in view of the commonness of A. rhodiolae in the Canadian Arctic and its broad distribution in Europe, the impact of the mite and its relationship with roseroot should be examined further in Nunavik and elsewhere.