931 resultados para interspecific association and correlation
Resumo:
BACKGROUND: Hallux valgus is one of the most common forefoot problems in females. Studies have looked at gait alterations due to hallux valgus deformity, assessing temporal, kinematic or plantar pressure parameters individually. The present study, however, aims to assess all listed parameters at once and to isolate the most clinically relevant gait parameters for moderate to severe hallux valgus deformity with the intent of improving post-operative patient prognosis and rehabilitation. METHODS: The study included 26 feet with moderate to severe hallux valgus deformity and 30 feet with no sign of hallux valgus in female participants. Initially, weight bearing radiographs and foot and ankle clinical scores were assessed. Gait assessment was then performed utilizing pressure insoles (PEDAR®) and inertial sensors (Physilog®) and the two groups were compared using a non-parametric statistical hypothesis test (Wilcoxon rank sum, P<0.05). Furthermore, forward stepwise regression was used to reduce the number of gait parameters to the most clinically relevant and correlation of these parameters was assessed with the clinical score. FINDINGS: Overall, the results showed clear deterioration in several gait parameters in the hallux valgus group compared to controls and 9 gait parameters (effect size between 1.03 and 1.76) were successfully isolated to best describe the altered gait in hallux valgus deformity (r(2)=0.71) as well as showed good correlation with clinical scores. INTERPRETATION: Our results, and nine listed parameters, could serve as benchmark for characterization of hallux valgus and objective evaluation of treatment efficacy.
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Ants are among the most problematic invasive species. They displace numerous native species, alter ecosystem processes, and can have negative impacts on agriculture and human health. In part, their success might stem from a departure from the discovery-dominance trade-off that can promote co-existence in native ant communities, that is, invasive ants are thought to be at the same time behaviorally dominant and faster discoverers of resources, compared to native species. However, it has not yet been tested whether similar asymmetries in behavioral dominance, exploration, and recruitment abilities also exist among invasive species. Here, we establish a dominance hierarchy among four of the most problematic invasive ants (Linepithema humile, Lasius neglectus, Wasmannia auropunctata, Pheidole megacephala) that may be able to arrive and establish in the same areas in the future. To assess behavioral dominance, we used confrontation experiments, testing the aggressiveness in individual and group interactions between all species pairs. In addition, to compare discovery efficiency, we tested the species' capacity to locate a food resource in a maze, and the capacity to recruit nestmates to exploit a food resource. The four species differed greatly in their capacity to discover resources and to recruit nestmates and to dominate the other species. Our results are consistent with a discovery-dominance trade-off. The species that showed the highest level of interspecific aggressiveness and dominance during dyadic interactions.
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The perceived low levels of genetic diversity, poor interspecific competitive and defensive ability, and loss of dispersal capacities of insular lineages have driven the view that oceanic islands are evolutionary dead ends. Focusing on the Atlantic bryophyte flora distributed across the archipelagos of the Azores, Madeira, the Canary Islands, Western Europe, and northwestern Africa, we used an integrative approach with species distribution modeling and population genetic analyses based on approximate Bayesian computation to determine whether this view applies to organisms with inherent high dispersal capacities. Genetic diversity was found to be higher in island than in continental populations, contributing to mounting evidence that, contrary to theoretical expectations, island populations are not necessarily genetically depauperate. Patterns of genetic variation among island and continental populations consistently fitted those simulated under a scenario of de novo foundation of continental populations from insular ancestors better than those expected if islands would represent a sink or a refugium of continental biodiversity. We, suggest that the northeastern Atlantic archipelagos have played a key role as a stepping stone for transoceanic migrants. Our results challenge the traditional notion that oceanic islands are the end of the colonization road and illustrate the significant role of oceanic islands as reservoirs of novel biodiversity for the assembly of continental floras.
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Post-translational protein modifications are crucial for many fundamental cellular and extracellular processes and greatly contribute to the complexity of organisms. Human HCF-1 is a transcriptional co-regulator that undergoes complex protein maturation involving reversible and irreversible post-translational modifications. Upon synthesis as a large precursor protein, HCF-1 undergoes extensive reversible glycosylation with β-N-acetylglucosamine giving rise to O-linked-β-N-acetylglucosamine (O-GlcNAc) modified serines and threonines. HCF-1 also undergoes irreversible site-specific proteolysis, which is important for one of HCF-1's major functions - the regulation of the cell-division cycle. HCF-1 O-GlcNAcylation and site-specific proteolysis are both catalyzed by a single enzyme with an unusual dual enzymatic activity, the O-GlcNAc transferase (OGT). HCF-1 is cleaved by OGT at any of six highly conserved 26 amino acid repeated sequences (HCF-1PRO repeats), but the mechanisms and the substrate requirements for OGT-mediated cleavage are not understood. In the present work, I characterized substrate requirements for OGT-mediated cleavage and O-GlcNAcylation of HCF-1. I identified key elements within the HCF-1PRO-repeat sequence that are important for proteolysis. Remarkably, an invariant single amino acid side-chain within the HCF-1PRO-repeat sequence displays particular OGT-binding properties and is essential for proteolysis. Additionally, I characterized substrate requirements for proteolysis outside of the HCF-1PRO repeat and identified a novel, highly O-GlcNAcylated OGT-binding sequence that enhances cleavage of the first HCF-1PRO repeat. These results link OGT association and its O-GlcNAcylation activities to HCF-1PRO-repeat proteolysis.
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Diffuse large B-cell lymphoma (DLBCL) with MYC rearrangement (MYC-R) carries an unfavorable outcome. We explored the prognostic value of the MYC translocation partner gene in a series of MYC-R de novo DLBCL patients enrolled in first-line prospective clinical trials (Groupe d'Etudes des Lymphomes de l'Adulte/Lymphoma Study Association) and treated with rituximab-anthracycline-based chemotherapy. A total of 774 DLBCL cases characterized for cell of origin by the Hans classifier were analyzed using fluorescence in situ hybridization with BCL2, BCL6, MYC, immunoglobulin (IG)K, and IGL break-apart and IGH/MYC, IGK/MYC, and IGL/MYC fusion probes. MYC-R was observed in 51/574 (8.9%) evaluable DLBCL cases. MYC-R cases were predominantly of the germinal center B-cell-like subtype 37/51 (74%) with no distinctive morphologic and phenotypic features. Nineteen cases were MYC single-hit and 32 cases were MYC double-hit (MYC plus BCL2 and/or BCL6) DLBCL. MYC translocation partner was an IG gene in 24 cases (MYC-IG) and a non-IG gene (MYC-non-IG) in 26 of 50 evaluable cases. Noteworthy, MYC-IG patients had shorter overall survival (OS) (P = .0002) compared with MYC-negative patients, whereas no survival difference was observed between MYC-non-IG and MYC-negative patients. In multivariate analyses, MYC-IG predicted poor progression-free survival (P = .0051) and OS (P = .0006) independently from the International Prognostic Index and the Hans classifier. In conclusion, we show in this prospective randomized trial that the adverse prognostic impact of MYC-R is correlated to the MYC-IG translocation partner gene in DLBCL patients treated with immunochemotherapy. These results may have an important impact on the clinical management of DLBCL patients with MYC-R who should be routinely characterized according to MYC partner gene. These trials are individually registered at www.clinicaltrials.gov as #NCT00144807, #NCT01087424, #NCT00169143, #NCT00144755, #NCT00140660, #NCT00140595, and #NCT00135499.
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International sport governing bodies (ISGBs) are built on the foundations of freedom of association and traditionally enjoy a large degree of autonomy in their decision-making. Their autonomy is increasingly confined, however, and their hierarchical self-governance is giving way to a more networked governance, in which different stakeholders exert power in different ways and in different contexts in a complex web of interrelationships. Taking a rationalist perspective on the autonomy of ISGBs, this article demonstrates that ISGBs are deploying strategies to safeguard their waning governing monopoly over international sport. Opting for an inductive approach, the authors present four possible conceptualizations of autonomy as applied to ISGBs, namely political autonomy, legal autonomy, financial autonomy and pyramidal autonomy. For each dimension, they describe the different strategies ISGBs wield in order to safeguard different dimensions of their autonomy. This article uses governance theories to hypothesize that the autonomy of ISGBs can be understood as 'pragmatic autonomy' since ISGBs only cede certain aspects of their autonomy under particular circumstances and when being subject to specific threats. Acting in a rationalist manner, they are able to keep control over governance developments in sport by using indirect and more subtle forms of governance.
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At the dawn of the eighteenth century chemistry was establishing itself as a physical science on its own right, after a long ancillary relationship with medicine and pharmacy, which had began two centuries before. This association, and the many changes that came along the scientific revolution spread into many walks of life. The Luso-Brazilian world, apparently so removed from the new developments, could not help to be touched by them, as this study shows, in which two contemporary medical authors are analysed. Both were Portuguese who had long lived in Brazil; both practised and wrote extensively on Medicine; both felt the influence of the new times, albeit in quite different ways.
Resumo:
L'objectiu del nostre estudi va ser conèixer si l'esport extraescolar i el temps dedicat setmanalment a les tecnologies de la informació i la comunicació (TIC) i jocs electrònics, tenen influència en el desenvolupament de la força de prensió de la mà i avantbraç en nens entre els 14 i 16 anys. Es va realitzar un estudi observacional de disseny transversal. La població objecte d'estudi van ser 39 nens de segon cicle de l'ESO. L'activitat física extraescolar i el temps dedicat setmanalment a les TIC i als jocs electrònics es van recollir mitjançant qüestionaris. Es va utilitzar el test d'handgrip per a la valoració de la força màxima voluntària de la mà i avantbraç del costat dominant. L'edat i la força de la mà dominant estan associades de forma estadísticament significativa, la força màxima voluntària (F=5,86; p=0,006) i el valor mig de la força sostinguda per sobre del 60% (F=4,5; p=0,02). A l'analitzar el grau d'activitat física (Kcal/setmana) respecte a la força màxima voluntària (r= 0,07; p= 0,716) i força sostinguda per sobre del 60% (r= 0,30; p= 0,09) observem una associació feble positiva i no estadísticament significativa. Si analitzem les hores setmanes TIC en relació a la força màxima voluntària observem una associació molt feble i no estadísticament significativa. La força de prensió de la mà en escolars està relacionada de forma positiva i estadísticament significativa amb l'edat i el pes corporal. No es relaciona amb el nivell d'activitat física i les hores dedicades a les TIC.
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Ten common doubts of chemistry students and professionals about their statistical applications are discussed. The use of the N-1 denominator instead of N is described for the standard deviation. The statistical meaning of the denominators of the root mean square error of calibration (RMSEC) and root mean square error of validation (RMSEV) are given for researchers using multivariate calibration methods. The reason why scientists and engineers use the average instead of the median is explained. Several problematic aspects about regression and correlation are treated. The popular use of triplicate experiments in teaching and research laboratories is seen to have its origin in statistical confidence intervals. Nonparametric statistics and bootstrapping methods round out the discussion.
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The chemistry of natural products has been remarkably growing in the past few decades in Brazil. Aspects related to the isolation and identification of new natural products, as well as their biological activities, have been achieved in different laboratories working on this subject in the country. More recently, the introduction of new molecular biology tools has strongly influenced the research on natural products, mainly those produced by microorganisms, creating new possibilities to assess the chemical diversity of secondary metabolites. This paper describes some ideas on how the research on natural products can have a considerable input from molecular biology in the generation of chemical diversity. We also explore the role of microbial natural products in mediating interspecific interactions and their relevance to ecological studies. Examples of the generation of chemical diversity are highlighted by using genome mining, mutasynthesis, combinatorial biosynthesis, metagenomics, and synthetic biology, while some aspects of microbial ecology are also discussed. The idea to bring up this topic is linked to the remarkable development of molecular biology techniques to generate useful chemicals from different organisms. Here, we focus mainly on microorganisms, even though similar approaches have also been applied to the study of plants and other organisms. Investigations in the frontier of chemistry and biology require interactions between different areas, characterizing the interdisciplinarity of this research field. The necessity of a real integration of chemistry and biology is pivotal to finding correct answers to a number of biological phenomena. The use of molecular biology tools to generate chemical diversity and control biosynthetic pathways is largely explored in the production of important biologically active compounds. Finally, we briefly comment on the Brazilian organization of research in this area, the necessity of new strategies for the graduation programs, and the establishment of networks as a way of organization to overcome some of the problems faced in the area of natural products.
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The purpose of this academic economic geographical dissertation is to study and describe how competitiveness in the Finnish paper industry has developed during 2001–2008. During these years, the Finnish paper industry has faced economically challenging times. This dissertation attempts to fill the existing gap between theoretical and empirical discussions concerning economic geographical issues in the paper industry. The main research questions are: How have the supply chain costs and margins developed during 2001–2008? How do sales prices, transportation, and fixed and variable costs correlate with gross margins in a spatial context? The research object for this case study is a typical large Finnish paper mill that exports over 90 % of its production. The economic longitudinal research data were obtained from the case mill’s controlled economic system and, correlation (R2) analysis was used as the main research method. The time series data cover monthly economic and manufacturing observations from the mill from 2001 to 2008. The study reveals the development of prices, costs and transportation in the case mill, and it shows how economic variables correlate with the paper mills’ gross margins in various markets in Europe. The research methods of economic geography offer perspectives that pay attention to the spatial (market) heterogeneity. This type of research has been quite scarce in the research tradition of Finnish economic geography and supply chain management. This case study gives new insight into the research tradition of Finnish economic geography and supply chain management and its applications. As a concrete empirical result, this dissertation states that the competitive advantages of the Finnish paper industry were significantly weakened during 2001–2008 by low paper prices, costly manufacturing and expensive transportation. Statistical analysis expose that, in several important markets, transport costs lower gross margins as much as decreasing paper prices, which was a new finding. Paper companies should continuously pay attention to lowering manufacturing and transporting costs to achieve more profitable economic performance. The location of a mill being far from markets clearly has an economic impact on paper manufacturing, as paper demand is decreasing and oversupply is pressuring paper prices down. Therefore, market and economic forecasting in the paper industry is advantageous at the country and product levels while simultaneously taking into account the economic geographically specific dimensions.
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Since its introduction, fuzzy set theory has become a useful tool in the mathematical modelling of problems in Operations Research and many other fields. The number of applications is growing continuously. In this thesis we investigate a special type of fuzzy set, namely fuzzy numbers. Fuzzy numbers (which will be considered in the thesis as possibility distributions) have been widely used in quantitative analysis in recent decades. In this work two measures of interactivity are defined for fuzzy numbers, the possibilistic correlation and correlation ratio. We focus on both the theoretical and practical applications of these new indices. The approach is based on the level-sets of the fuzzy numbers and on the concept of the joint distribution of marginal possibility distributions. The measures possess similar properties to the corresponding probabilistic correlation and correlation ratio. The connections to real life decision making problems are emphasized focusing on the financial applications. We extend the definitions of possibilistic mean value, variance, covariance and correlation to quasi fuzzy numbers and prove necessary and sufficient conditions for the finiteness of possibilistic mean value and variance. The connection between the concepts of probabilistic and possibilistic correlation is investigated using an exponential distribution. The use of fuzzy numbers in practical applications is demonstrated by the Fuzzy Pay-Off method. This model for real option valuation is based on findings from earlier real option valuation models. We illustrate the use of number of different types of fuzzy numbers and mean value concepts with the method and provide a real life application.
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ABSTRACT This study aimed to identify wavelengths based on leaf reflectance (400-1050 nm) to estimate white mold severity in common beans at different seasons. Two experiments were carried out, one during fall and another in winter. Partial Least Squares (PLS) regression was used to establish a set of wavelengths that better estimates the disease severity at a specific date. Therefore, observations were previously divided in two sub-groups. The first one (calibration) was used for model building and the second subgroup for model testing. Error measurements and correlation between measured and predicted values of disease severity index were employed to provide the best wavelengths in both seasons. The average indexes of each experiment were of 5.8% and 7.4%, which is considered low. Spectral bands ranged between blue and green, green and red, and red and infrared, being most sensitive for disease estimation. Beyond the transition ranges, other spectral regions also presented wavelengths with potential to determine the disease severity, such as red, green, and near infrared.
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Tämän tutkielman tarkoituksena oli löytää keinoja uusien tuotteiden tavoitevarastoarvojen määrittämisen helpottamiseksi case-yrityksessä. Ongelma on seurausta siitä, ettei uusille tuotteille ole saatavissa kysyntädataa. Oikeelliset tavoitevarastoarvot on tärkeitä case-yritykselle hävikin minimoimisen ja erityisesti asiakastyytyväisyyden vuoksi. Tutkittavaa aihetta lähestyttiin päivittäistavarakaupan strategisten menestystekijöiden sekä varastonhallinnan kautta. Teoriaosuuden pohjalta toteutettiin empiirinen osio, jossa etsittiin case-yrityksen kahden tuoteryhmän kysyntää selittäviä tekijöitä paneeliregression avulla. Ensin kuitenkin tutkittiin tuoteryhmien yleistä kysynnän rakennetta erilaisten kysyntäkuvaajien sekä korrelaatiomatriisien avulla. Tavoitevarastoarvoon eniten vaikuttava tekijä on kysyntä. Brändi ja hinta muodostuivat puolestaan vahvimmiksi kysyntää määrittäviksi muuttujiksi. Kysyntää arvioitaessa muut sitä nostavat muuttujat tulee aina miettiä tapauskohtaisesti. Mehukeitoilla kysyntää nostivat eniten vahva brändi ja suuri pakkauskoko. Juustoraasteilla puolestaan alhainen hinta ja pieni pakkauskoko olivat keskeisimmät myyntiin vaikuttavat tekijät. Tuoteryhmien muut kysyntää nostavat ominaisuudet olivat samoja, kuin tuoteryhmän suosituimmilla tuotteilla.
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OBJECTIVE: To evaluate the applicability of the main categories of risk and morphological factors in the prognosis of gastrointestinal stromal tumors. METHODS: we retrospectively studied fifty-four cases of GIST, assessing the main prognostic factors of this neoplasis: risk levels, topography, size, mitotic index, necrosis, histological subtype and immunophenotype. We also verified their association and the reduction of overall survival. RESULTS: Univariate analysis showed that tumors with mitoses number greater than 5 per 50CGA (high-power fields), the presence of necrosis and a high risk for both the systems proposed by Fletcher and Miettinen had a significant association with reduced survival (p = 0.00001, 0.0056, 0.03 and 0.009, respectively). The remaining analyzed factors (size, histological subtype, topography and immunophenotype) had no such association. Multivariate analysis (Jacard index) showed that the Miettinen degree of risk was the one that best correlated with prognosis. CONCLUSION: the risk criteria of Fletcher and Miettinen are important in assessing the prognosis of patients with gastrointestinal stromal tumors, especially the latter, which adds to the mitotic index and the presence of tumor necrosis.