Estudamos sistemas de passeios aleatórios sobre os vértices de um grafo completo. Inicialmente há uma partícula em cada vértice do grafo das quais somente uma está ativa, as outras estão inativas. A partícula ativa realiza um passeio aleatório simples a tempo discreto com tempo de vida que depende do passado do processo, movendo-se ao longo de elos. Quando uma partícula ativa encontra uma inativa, esta se ativa; quando salta sobre um vértice já visitado, morre. O objetivo desta dissertação é estudar a cobertura do grafo completo, ou seja, a proporção de vértices visitados ao fim do processo, quando o número $n$ de vértices tende ao infinito. Analisamos as equações de campo médio para o processo descrito acima, comparando os seus resultados com os do modelo aleatório. Aqui, os resultados do campo médio parecem reproduzir os do modelo aleatório. Depois, apresentamos um estudo similar entre o modelo estocástico e as equações de campo médio para o caso em que cada partícula possui 2 vidas. Finalmente, observamos a cobertura do grafo completo para as equações de campo médio quando o número de vidas por partículas é maior que dois. / We study random walks systems on complete graphs. Initially there is a particle at each vertex of the graph; only one is active and the other are inactive. An active particle performs a discrete-time simple random walk with lifetime depending on the past of the process moving along edges. When an active particle hits an inactive one, the latter is activated. When it jumps on a vertex which has been visited before it dies. The goal of this work is to study the coverage of the complete graph, that is, the proportion of visited vertices at the end of the process, when the number of vertices goes to infinity. We analyze the mean field equations to the process cited above, comparing their results with the ones of the random model. Here the results of the mean field approach seem to reproduce the ones of the random model. After we present a similar study between the stochastic model and mean field approximation to the case that each particle has 2 lifes. Finally we observe the coverage of the complete graph to the mean-field equations when the number of lifes by particle is bigger than two.

A confecção de próteses totais envolve uma série de procedimentos técnicos complexos. No entanto, a simplificação dessa sequência de procedimentos pode ser tão eficazes quanto os convencionais, mas com menor gasto de tempo e recursos. O objetivo deste estudo foi quantificar os custos envolvidos com a confecção de próteses totais com um método simplificado em comparação a um convencional. A amostra foi formada por pacientes desdentados totais solicitando tratamento com próteses totais duplas, que foram divididos aleatoriamente em dois grupos: o Grupo S recebeu próteses totais confeccionadas por um método simplificado, enquanto que o Grupo C recebeu próteses confeccionadas convencionalmente. Os custos diretos e indiretos de cada procedimento foram calculados por participante, incluindo sessões imprevistas. O estudo foi realizado com 19 e 21 participantes nos grupos S e C, respectivamente, e comparações entre os dois grupos foram feitas por meio dos testes de Mann-Whitney e t de Student (&alpha;=0,05). A confecção das próteses demandou do operador um tempo mediano de 173,2 e 284,5 min. para os grupos S e C, respectivamente, enquanto os tempos para o auxiliar foram 46,6 e 61,7 min. (diferenças significantes, P<0,05). Os grupos não diferiram significantemente na fase de ajustes pós-instalação. O grupo S também apresentou valores menores que C durante a fase de confecção, mas não durante os ajustes, para custos com materiais empregados e tempo despendido pelo paciente. No total, o método simplificado reduziu o custo direto do tratamento em 34,9%. Conclui-se que o método simplificado é menos oneroso ao paciente e sistema de saúde, quando comparado a um protocolo convencional para a reabilitação do paciente edentado. / Complete denture fabrication involves a series of complex technical procedures. Nevertheless, simplified methods may be as effective as conventional ones albeit the lower use of time and resources. The aim of this study is to quantify the costs of complete denture fabrication by means of a simplified method compared with a conventional protocol. A sample of edentulous patients needing conventional maxillary and mandibular complete dentures was randomly divided into: group S, which received dentures fabricated by means of a simplified method, and group C, which received conventionally fabricated dentures. We calculated direct and indirect costs for each participant including unscheduled procedures. This study assessed 19 and 20 participants allocated in groups S and C, respectively, and comparisons between groups were conducted by means of the Mann-Whitney and Students t test (&alpha;=0,05). Complete denture fabrication demanded median time periods of 173,2 and 284,5 min from the operator for groups S and C respectively, and 46.6 and 61.7 min from the dental assistant (significant differences, P<0.05). There was no difference between groups regarding postinsertion adjustments. Group S also showed lower values than C during the fabrication stage, but not during adjustments, for costs with materials and time spent by patients. In summary, the simplified method reduced direct treatment costs in 34.9%. It can be concluded that the simplified method is less costly for patients and health system when compared with a conventional protocol for the rehabilitation of edentulous patients.

O objetivo deste trabalho foi avaliar, por meio de estudo laboratorial e clínico, a eficácia de soluções de hipoclorito alcalino (0,25% e 0,5%) e à base de mamona (Ricinus communis) a 10% quanto à ação antimicrobiana frente a micro-organismos específicos, por meio da contagem de Unidades Formadoras de Colônias (UFC). No estudo laboratorial, a partir de matrizes metálicas quadrangulares (10 x 2 mm), foram confeccionados 360 corpos de prova de resina acrílica termopolimerizável (Lucitone 550), os quais foram esterilizados em micro-ondas (650W, por 6 minutos), contaminados com cepas de Staphylococcus aureus, Pseudomonas aeruginosa, Candida albicans, Bacillus subtilis, Escherichia coli, Streptococcus mutans, Enterococcus faecalis e Candida glabrata e imersos (20 minutos) em soluções higienizadoras (n=10): Grupo A - Hipoclorito de sódio 0,25%; Grupo B - Hipoclorito de sódio 0,5%; Grupo C - Solução de mamona a 10%; Grupo D (Controle positivo) - solução salina e Grupo E (Controle negativo) - sem contaminação e imerso em solução salina (n=5). Em seguida, foram lavados em solução salina e imersos em meio de cultura líquido (Letheen), a partir do qual foram obtidas diluições seriadas (100 e 10-3), as quais foram semeadas em meios de cultura seletivos. Após incubação a 37ºC por 24 horas, as colônias foram contadas e os valores de UFC/mL calculados. No estudo clínico, 64 pacientes, usuários de próteses totais, foram orientados a escovar suas próteses (escova Bitufo® e sabonete líquido neutro) três vezes ao dia e imergí-las (20 minutos), uma vez ao dia, em soluções: Solução 1 - Hipoclorito de sódio 0,25%; Solução 2 - Hipoclorito de sódio 0,5%; Solução 3 - Solução de mamona a 10% e Solução 4 - solução salina (controle). De acordo com uma sequência aleatorizada, cada solução foi utilizada por 7 dias, com um período de wash out entre elas. A avaliação da ação antimicrobiana foi realizada antes dos uso dos produtos (Baseline) e após os 7 dias de uso de cada uma das soluções, por meio da contagem de Unidades Formadoras de Colônias (UFC) de Streptococcus mutans, Candida spp. e gram negativos. Para coleta do biofilme, cada prótese total superior foi colocada em placa de Petri e a superfície interna escovada (escova Tek e solução salina) por 2 minutos, sendo a suspensão transferida para tubo de ensaio. Após diluições decimais (100 até 10-3), alíquotas de 50 &mu;L foram semeadas em placas de Petri contendo Mitis Salivarius Agar Base, Chromagar® Candida e Mac Conkey Agar para a detecção de Streptococcus mutans, Candida spp. ou gram negativo, respectivamente. Após incubação a 37ºC (em microaerofilia durante 48-72 horas para grupo mutans e aerobiose durante 48 horas para Candida spp. e gram negativo), de acordo com morfologia típica, o número de colônias características foi mensurado e o número de UFC/mL calculado. Os dados obtidos foram transformados de acordo com a fórmula log10 (UFC+1) e analisados estatisticamente por meio do teste t de Student (&alpha;=0,05), para a análise laboratorial, e teste de Friedman (&alpha;=0,05), para a análise clínica. Os resultados mostraram que, no estudo laboratorial, as soluções de hipoclorito de sódio (0,25% e 0,5%) eliminaram completamente todos os micro-organismos. A solução de mamona eliminou completamente B. subtilis, não apresentou efeito sobre E. faecalis e apresentou ação antimicrobiana moderada frente às demais cepas, havendo redução significante (p < 0,05) do número de UFC quando comparado com o grupo D (controle positivo). No estudo clínico, houve diferença significante entre as soluções (P < 0,001), sendo que o hipoclorito de sódio a 0,5% apresentou ação efetiva sobre todos os micro-organismos avaliados (Candida spp., S. mutans e gram negativos); o hipoclorito de sódio 0,25%, ação efetiva sobre S. mutans e moderada sobre Candida spp. e gram negativos, e a solução de mamona, ação efetiva sobre S. mutans e moderada contra Candida spp. A espécie de Candida mais frequentemente isolada foi C. albicans, seguida pelas espécies C. tropicalis e C. glabrata. Concluiu-se que a solução de hipoclorito de sódio 0,5% foi a mais efetiva, apresentando ação antimicrobiana sobre ambos os biofilmes (in vitro e in vivo), seguida pela solução de hipoclorito de sódio 0,25% que apresentou ação antimicrobiana sobre o biofilme in vitro e sobre S. mutans (biofilme in vivo). A solução de mamona (10%) foi a menos efetiva, apresentando ação antimicrobiana sobre B. subtilis (biofilme in vitro) e S. mutans (biofilme in vivo). / The objective of this study was to evaluate, through laboratory and clinical study, the efficacy of alkaline hypochlorite solutions (0.25% and 0.5%) and 10% castor oil solution (Ricinus communis) about the antimicrobial action against specific microorganisms, by counting the number of Colony Forming Units (CFU). In the laboratory study, 360 denture base acrylic resin specimens (Lucitone 550) were obtained from square metal matrix (10 mm x 2 mm), which were sterilized with microwave (650W, for 6 minutes), contaminated with Staphylococcus aureus, Pseudomonas aeruginosa, Candida albicans, Bacillus subtilis, Escherichia coli, Streptococcus mutans, Enterococcus faecalis and Candida glabrata and immersed (20 minutes) in the hygiene solutions (n = 10): Group A - 0.25% Sodium Hypochlorite; Group - B - 0.5% Sodium hypochlorite; Group C - 10% Castor oil solution; Group D (Positive Control) - saline and Group E (Negative Control) - no contamination and immersed in saline (n = 5). The specimens were washed in saline solution and immersed in liquid culture medium (Letheen), from which were obtained serial dilutions (100 to 10-3) and seeded into selective solid media. After incubation at 37º C for 24 hours, the colonies were counted and the values of CFU/mL calculated. In the clinical study, 64 complete denture wearers were instructed to brush their dentures (Bitufo ® brush and liquid neutral soap) three times a day and to soak them (20 minutes), once a day, in the solutions: Solution 1 - 0.25% Sodium Hypochlorite; Solution 2 - 0.5% Sodium hypochlorite; Solution 3 - 10% Castor oil and Solution 4 - saline (control). According to a randomized sequence, each solution was used for 7 days, with a period of wash out between them. The evaluation of the antimicrobial action was performed before the use of the products (Baseline) and after 7 days after using each solution, by counting the Colony Forming Units (CFU) of Streptococcus mutans, Candida spp. and gram negative. For collection of the biofilm, each upper complete denture was placed in a Petri dish, the internal surface was brushed with saline solution for 2 minutes and the suspension was transferred to a test tube. After decimal dilutions (100 to 10-3), aliquots of 50 uL were seeded inside Petri dishes containing Mitis Salivarius Agar Base, Candida Chromagar ® and Mac Conkey Agar for the detection of Streptococcus mutans, Candida spp. or gram negative, respectively. After incubation at 37° C (in microaerophilic conditions for 48-72 hours for mutans and aerobiosis for 48 hours for Candida spp. and gram negative), in accordance with characteristic morphology, the number of characteristic colonies was countedand the number of CFU/ml calculated. Data were processed following transformation into the formula log10 (CFU +1) and statistically analyzed using the Student t test (&alpha; = 0.05) for laboratory analysis, and Friedman test (&alpha; = 0.05), for clinical analysis. The results showed that, in the laboratory study, sodium hypochlorite (0.25% and 0.5%) eliminated completely all microorganisms. The Castor oil solution eliminated B. subtilis, had no effect on E. faecalis and showed moderate antimicrobial activity against other strains, with a significant reduction (p <0.05) in the number of CFU compared with group D (positive control). In the clinical study, there was significant difference between the solutions (P <0.001), and 0.5% sodium hypochlorite had effective action on all evaluated microorganisms (Candida spp., S. mutans and gram negative); 0.25% sodium hypochlorite had effective action on S. mutans and moderate on Candida spp. and gram negative, and the castor oil solution had effective action on S. mutans and moderate against Candida spp. . The Candida species most often isolated was C. albicans, followed by the species C. tropicalis and C. glabrata. It was concluded that the solution of 0.5% sodium hypochlorite was the most effective presenting antimicrobial action on both biofilms (in vitro and in vivo), followed by 0.25% sodium hypochlorite solution that showed antimicrobial activity on biofilms in vitro and on S. mutans (biofilm in vivo). The 10% castor oil was less effective, with antimicrobial action on Bacillus subtilis (biofilm in vitro) and S. mutans (biofilm in vivo).

Humane Astroviren (HAstV) stellen wichtige Erreger kindlicher Gastroenteritiden dar, die in ihrer Bedeutung lange Zeit unterschätzt wurden. Sie werden in acht Serotypen klassifiziert, die nach dem bisherigen Kenntnisstand mit den Genotypen korrespondieren. Ziel dieser Arbeit war es, Einsicht in die molekulare Epidemiologie der in Deutschland zirkulierenden Astroviren zu vermitteln. Eine HAstV-spezifische RT-PCR bildete die Grundlage für die phylogenetische Analyse eines Genomabschnitts, der für die Kapsidproteine des Virus kodiert. Dazu wurden 16 deutsche Astrovirusisolate aus den Jahren 1997-1999 unter Einbeziehung bereits publizierter Sequenzdaten der Serotypen 1-8 untersucht. In Anlehnung an ein in der vorliegenden Literatur verwendetes Klassifizierungsschema erfolgte die Einteilung der deutschen Isolate in unterschiedliche Genotypen. Hierbei bildete eine Konvergenz von mindestens 85% das Kriterium für die Zuordnung differenter Isolate zum gleichen Genotyp. Es konnte gezeigt werden, dass in Deutschland wenigstens vier HAstV-Genotypen (1-4) kozirkulieren. Über dem betrachteten Genomabschnitt stimmten einige Isolate aus unterschiedlichen geografischen Regionen in ihrer Sequenz überein. Im Rahmen dieser Arbeit wurde erstmals die Totalsequenz eines humanen Astrovirus vom Serotyp 3 ermittelt. Während in der phylogenetischen Analyse des betreffenden Isolats nur ein Genomabschnitt betrachtet wurde, ließ sich an seiner Totalsequenz demonstrieren, dass die Einordnung in den Geno- bzw. Serotyp 3 auch in anderen Genomregionen Gültigkeit besitzt. Analog zu den bisher bekannten Gesamtgenomsequenzen der Serotypen 1, 2 und 8 lassen sich drei überlappende offene Leseraster (ORFs) identifizieren. In den beiden am 5'-Ende gelegenen ORFs 1a und 1b erweisen sich die putativen Motive der Protease und der RNA-Polymerase zwischen den vier Serotypen als hochkonserviert, ebenso wie vier potentielle Transmembrandomänen, ein ribosomales frameshift-Signal und ein nukleäres Lokalisationssignal. In dem am 3'-Ende gelegenen ORF 2 befinden sich drei hochkonservierte potentielle N-Glykosylierungs-Sites sowie ein hochkonserviertes Glykosaminoglykan-Attachment-Site. Ein wesentlicher Befund im Zusammenhang mit der Totalsequenz ist der Nachweis einer 45 Nukleotide umfassenden Deletion im ORF1a im Originalmaterial (Stuhl). Diese wurde bisher nur bei Astroviren gefunden, die in Zellen kultiviert wurden. Von Interesse und weiteren Untersuchungen vorbehalten ist ihre Nähe zur nukleären Lokalisationssequenz, die für die Beeinflussung des Zielzell-Tropismus von Astroviren verantwortlich sein könnte. / Human astroviruses (HastV) are an important cause of infantile gastroenteritis. To date, there are eight recognized serotypes which correlate with genotypes. The aim of this study was to investigate the molecular epidemiology of astroviruses circulating in Germany. Based on a HAstV-specific RT-PCR, phylogenetic analysis of a segment of the capsid protein gene was performed. The examination included sequence data of 16 German astrovirus isolates from the years 1997-1999 as well as published sequence information of the serotypes 1-8. Molecular typing was carried out following published classification strategies. The criterion for classification of isolates into one genotype was sequence identity of at least 85%. Astroviruses of at least four different genotypes (1-4) were found to cocirculate in Germany. The nucleotide sequences of several isolates from different geographical regions were identical. As part of this study, the complete genomic sequence of a type 3 human astrovirus was determined. The classification of the virus as a genotype 3 astrovirus as suggested by phylogenetic analysis over a limited genome section was supported by sequence comparison over two different genomic regions. Similar to the known total sequences of serotypes 1,2 and 8, three overlapping open reading frames (ORFs) were identified. The 5' end ORFs 1a and 1b contain the putative protease and polymerase motifs, which are highly conserved between the four serotypes. A high degree of sequence identity was also found for four potential transmembrane domains, a ribosomal frameshift signal and a nuclear localisation signal. The 3' end ORF 2 encodes three almost totally conserved potential N-glycosylation sites and one highly conserved putative glycosaminoglycan attachment site. As an outstanding feature, the virus, which was isolated and sequenced directly from diarrheal feces, presents a 45-nucleotide deletion in ORF 1 a. This deletion has previously only been found in cell cultured astroviruses. Further studies are needed to determine whether all viral genomes within the quasispecies carry the deletion.

Recursion is a fundamental tool of mathematics used to define, construct, and analyze mathematical objects. This work employs induction, sieving, inversion, and other recursive methods to solve a variety of problems in the areas of algebraic number theory, topological and combinatorial graph theory, and analytic probability and statistics. A common theme of recursively defined functions, weighted sums, and cross-referencing sequences arises in all three contexts, and supplemented by sieving methods, generating functions, asymptotics, and heuristic algorithms. In the area of number theory, this work generalizes the sieve of Eratosthenes to a sequence of polynomial values called polynomial-value sieving. In the case of quadratics, the method of polynomial-value sieving may be characterized briefly as a product presentation of two binary quadratic forms. Polynomials for which the polynomial-value sieving yields all possible integer factorizations of the polynomial values are called recursively-factorable. The Euler and Legendre prime producing polynomials of the form n2+n+p and 2n2+p, respectively, and Landau's n2+1 are shown to be recursively-factorable. Integer factorizations realized by the polynomial-value sieving method, applied to quadratic functions, are in direct correspondence with the lattice point solutions (X,Y) of the conic sections aX2+bXY +cY2+X-nY=0. The factorization structure of the underlying quadratic polynomial is shown to have geometric properties in the space of the associated lattice point solutions of these conic sections. In the area of combinatorial graph theory, this work considers two topological structures that are used to model the process of homologous genetic recombination: assembly graphs and chord diagrams. The result of a homologous recombination can be recorded as a sequence of signed permutations called a micronuclear arrangement. In the assembly graph model, each micronuclear arrangement corresponds to a directed Hamiltonian polygonal path within a directed assembly graph. Starting from a given assembly graph, we construct all the associated micronuclear arrangements. Another way of modeling genetic rearrangement is to represent precursor and product genes as a sequence of blocks which form arcs of a circle. Associating matching blocks in the precursor and product gene with chords produces a chord diagram. The braid index of a chord diagram can be used to measure the scope of interaction between the crossings of the chords. We augment the brute force algorithm for computing the braid index to utilize a divide and conquer strategy. Both assembly graphs and chord diagrams are closely associated with double occurrence words, so we classify and enumerate the double occurrence words based on several notions of irreducibility. In the area of analytic probability, moments abstractly describe the shape of a probability distribution. Over the years, numerous varieties of moments such as central moments, factorial moments, and cumulants have been developed to assist in statistical analysis. We use inversion formulas to compute high order moments of various types for common probability distributions, and show how the successive ratios of moments can be used for distribution and parameter fitting. We consider examples for both simulated binomial data and the probability distribution affiliated with the braid index counting sequence. Finally we consider a sequence of multiparameter binomial sums which shares similar properties with the moment sequences generated by the binomial and beta-binomial distributions. This sequence of sums behaves asymptotically like the high order moments of the beta distribution, and has completely monotonic properties.

<p>The overall aim of this thesis is to compare different methods for calculation of Core-Level shifts in metallic alloys. The methods compared are the Initial State model, the Complete screening and the Transition state model. Core-level shifts can give information of chemical bonding and about the electronic structure in solids.</p><p>The basic theory used is the so-called Density-Functional-Theory, in conjunction with the Local-Density Approximation and the Coherent-Potential- Approximation. The metallic alloys used are Silver-Palladium, Copper-Palladium, Copper-Gold and Copper-Platinum, all inface-centered-cubic configuration.</p><p>The complete screening- and the transition-state model are found to be in better agreement with experimental results than those calculated with the initial state model. This is mainly due to the fact that the two former models includes final-state effects, whereas the last one do not. The screening parameters within the Coherent-Potential approximation are also investigated. It is found that the Screened-Impurity Model can extend the validity of the Coherent-Potential-Approximation and increase it's accuracy.</p>

Thesis (M.Ed.)--North-West University, Potchefstroom Campus, 2007.

The game of Hex is of interest to the mathematics, algorithms, and artificial intelligence communities. It is a classical PSPACE-complete problem, and its invention is intrinsically tied to the Four Colour Theorem and the well-known strategy-stealing argument. Nash, Shannon, Tarjan, and Berge are among the mathematicians who have researched and published about this game. In this thesis we expand on previous research, further developing the mathematical theory and algorithmic techniques relating to Hex. In particular, we identify new classes of moves that can be pruned from consideration, and devise new algorithms to identify connection strategies efficiently. As a result of these theoretical improvements, we produce an automated solver capable of solving all 8 x 8 Hex openings and most 9 x 9 Hex openings; this marks the first time that computers have solved all Hex openings solved by humans. We also produce the two strongest automated Hex players in the world --- Wolve and MoHex --- and obtain both the gold and silver medals in the 2008 and 2009 International Computer Olympiads.

Computationally hard problems are routinely encountered during the course of solving practical problems. This is commonly dealt with by settling for less than optimal solutions, through the use of heuristics or approximation algorithms. This dissertation examines the alternate possibility of solving such problems exactly, through a detailed study of one particular problem, the maximum clique problem. It discusses algorithms, implementations, and the application of maximum clique results to real-world problems. First, the theoretical roots of the algorithmic method employed are discussed. Then a practical approach is described, which separates out important algorithmic decisions so that the algorithm can be easily tuned for different types of input data. This general and modifiable approach is also meant as a tool for research so that different strategies can easily be tried for different situations. Next, a specific implementation is described. The program is tuned, by use of experiments, to work best for two different graph types, real-world biological data and a suite of synthetic graphs. A parallel implementation is then briefly discussed and tested. After considering implementation, an example of applying these clique-finding tools to a specific case of real-world biological data is presented. Results are analyzed using both statistical and biological metrics. Then the development of practical algorithms based on clique-finding tools is explored in greater detail. New algorithms are introduced and preliminary experiments are performed. Next, some relaxations of clique are discussed along with the possibility of developing new practical algorithms from these variations. Finally, conclusions and future research directions are given.

The main aim of this thesis was to evaluate the effect of prednisolone and valaciclovir in a large number of Bell's palsy patients. The incidence and intensity of pain around the ear, in the face or in the neck during the first two months of palsy, and its prognostic value, was also assessed. We also investigated how study design and choice of analysis method affect the rate of facial recovery. Furthermore, the agreement between the Sunnybrook, House-Brackmann and Yanagihara facial grading systems was evaluated. From May 2001 to September 2007, a prospective, randomised, double-blind, placebo-controlled, multicentre trial with 12-month follow-up was performed in patients with Bell's palsy. Of 839 randomised patients, 829 were included in the intention-to-treat analysis; 206 received placebo plus placebo, 210 prednisolone plus placebo, 207 valaciclovir plus placebo, and 206 prednisolone plus valaciclovir. Time to recovery was significantly shorter in the 416 patients who received prednisolone compared with the 413 who did not (p&lt;0.0001). At 12 months, 300 of 416 patients (72%) in the prednisolone group had recovered compared with 237 of 413 patients (57%) in the no prednisolone group (p&lt;0.0001). Valaciclovir was not found to affect time to facial recovery or outcome at 12 months. Prednisolone and/or valaciclovir did not affect the incidence or intensity of pain. Presence of pain at day 11 to 17 indicated a worse prognosis for facial recovery at 12 months. We also found that recovery rates in a Bell's palsy trial are substantially affected by the choice of analysis method and definition of facial recovery. We used weighted Kappa statistics in 100 examinations of patients with facial palsy to assess the agreement between the Sunnybrook, House-Brackmann and Yanagihara scales. The highest agreement was found between the regional Sunnybrook and Yanagihara scales. An evaluative difference between the Sunnybrook and House-Brackmann systems was observed.