26 research outputs found
Root morphology of mandibular molars: a cone-beam computed tomography study
Background: The aim of the study was to assess the number and anatomical classification of roots and root canals of first and second mandibular molars using cone-beam computed tomography (CBCT) in a Chilean population.
Materials and methods: This study evaluated the CBCT scans of 289 patients aged between 14 and 86 years, obtaining a sample of 1022 mandibular first and second molars. The number of roots and root canals was evaluated according to the anatomical classification proposed by Ahmed in 2016. Data were analysed using Pearson’s chi-squared test and ANOVA.
Results: Nine hundred fifty-one (93.05%) molars had two roots, while the remaining 71 (6.95%) molars had one root. The most frequent root and root canal morphologies found were: 2MM M2 D1 (29.65%), 2MM M2-1 D1 (22.3%) and 2MM M1 D1 (13.4%) (M — mesial, D — distal), with a total of 32 different anatomical distributions. C-shaped canals were present in 56 molars and were more frequently found in women than in men (7.1% vs. 3.88%; p = 0.024).
Conclusions: The analysis of internal anatomy using CBCT revealed a highly variable distribution of root canals. The most frequent morphology found in mandibular molars in a Chilean population was two roots and three canals
Naming a phantom – the quest to find the identity of Ulluchu, an unidentified ceremonial plant of the Moche culture in Northern Peru
The botanical identification of Ulluchu, an iconic fruit frequently depicted in the art of the pre-Columbian Moche culture that flourished from A.D. 100–800 on the Peruvian north coast, has eluded scientists since its documentation in ceramics in the 1930s. Moche fine-line drawings of Ulluchu normally depict seed-pods or seeds floating in the air in sacrificial scenes, associated with runners and messengers or intoxicated priests. It is a grooved, comma-shaped fruit with an enlarged calyx found mainly in fine-line scenes painted on Moche ceramics. The term first appeared without linguistic explanation in the work of pioneer Moche scholar Rafael Larco Hoyle, and the identification of the plant was seen as the largest remaining challenge in current archaebotany at the Peruvian North coast. The name Ulluchu seems to have been coined by Larco. According to his description, the name originated in the Virú River valley, and is supposedly of Mochica origin. However, there is no linguistic evidence that such a term indeed existed in the Mochica or Yunga language
Shadows of the colonial past – diverging plant use in Northern Peru and Southern Ecuador
This paper examines the traditional use of medicinal plants in Northern Peru and Southern Ecuador, with special focus on the Departments of Piura, Lambayeque, La Libertad, Cajamarca, and San Martin, and in Loja province, with special focus on the development since the early colonial period. Northern Peru represents the locus of the old Central Andean "Health Axis." The roots of traditional healing practices in this region go as far back as the Cupisnique culture early in the first millennium BC
Produção e qualidade do leite em sistemas de produção da região leiteira de Pelotas, RS, Brasil
Fatores ambientais que afetam a produção e a composição do leite em rebanhos assistidos por cooperativas no Rio Grande do Sul
Com o diabo no corpo: os terríveis papagaios do Brasil colônia
Desde a Antiguidade, papagaios, periquitos e afins (Psittacidae) fascinaram os europeus por seu vivo colorido e uma notável capacidade de interação com seres humanos. A descoberta do Novo Mundo nada faria além de acrescentar novos elementos ao tráfico de animais exóticos há muito estabelecido pelos europeus com a África e o Oriente. Sem possuir grandes mamíferos, a América tropical participaria desse comércio com o que tinha de mais atrativo, essencialmente felinos, primatas e aves - em particular os papagaios, os quais eram embarcados em bom número. Contudo, a julgar pelos documentos do Brasil colônia, esses voláteis podiam inspirar muito pouca simpatia, pois nenhum outro animal - exceto as formigas - foi tantas vezes mencionado como praga para a agricultura. Além disso, alguns psitácidas mostravam-se tão loquazes que inspiravam a séria desconfiança de serem animais demoníacos ou possessos, pois só três classes de entidades - anjos, homens e demônios - possuíam o dom da palavra. Nos dias de hoje, vários representantes dos Psittacidae ainda constituem uma ameaça para a agricultura, enquanto os indivíduos muito faladores continuam despertando a suspeita de estarem possuídos pelo demônio. Transcendendo a mera curiosidade, essa crença exemplifica o quão intrincadas podem ser as relações do homem com o chamado “mundo natural”, revelando um universo mais amplo e multifacetado do que se poderia supor a princípio. Nesse sentido, a existência de aves capazes de falar torna essa relação ainda mais complexa e evidencia que as dificuldades de estabelecer o limite entre o animal e o humano se estendem além dos primatas e envolvem as mais inusitadas espécies zoológicas.Since ancient times, parrots and their allies (Psittacidae) have fascinated Europeans by their striking colors and notable ability to interact with human beings. The discovery of the New World added new species to the international exotic animal trade, which for many centuries had brought beasts to Europe from Africa and the Orient. Lacking large mammals, tropical America participated in this trade with its most appealing species, essentially felines, primates and birds - especially parrots - which were shipped in large numbers. It should be noted, however, that at times these birds were not well liked. In fact, according to documents from colonial Brazil, only the ants rank higher than parrots as the animals most often mentioned as agricultural pests. On the other hand, some of these birds were so chatty that people suspected them to be demonic or possessed animals, since only three classes of beings - angels, men and demons - have the ability to speak. Nowadays, several Psittacidae still constitute a threat to agriculture, and the suspicion that extremely talkative birds were demon possessed has also survived. More than a joke or a mere curiosity, this belief exemplifies how intricate man’s relationships with the “natural world” may be. In this sense, the existence of birds that are able to speak adds a further twist to these relationships, demonstrating that the problem of establishing a boundary between the animal and the human does not only involve primates, but also includes some unusual zoological species
Correlations between Herd Life and Type Traits in Quebec Holsteins
Long productive life is a primary breeding objective of dairy farmers. Herd life and lifetime profitability are two of the most important factors influencing a cow’s profitability. Various tools have been introduced to aid farmers in obtaining efficient, high producing, sustainable cows, of which type traits, which evaluate an animal’s physical characteristics, are the most popular. Dairy producers have bred for high producing and healthy cows, and many of their decisions are based on a cow’s conformation traits. The objective of this study was to estimate the relationship between various lengths of productive life and type traits for Quebec Holstein cows.[...
Genetic Analysis of Herd Life in Quebec Holsteins Using Weibull Models
A genetic study was conducted to analyze herd life in Quebec Holstein herds utilizing Weibull regression models. It has been shown that this class of models are more appropriate to analyze herd life data in dairy cattle than the usual linear models (Ducrocq, 1987). They belong to the general class of survival models known as “proportional hazards models”, which assume that the hazard functions for different individuals are proportional over time. The possibility to include timedependent covariates and to define different strata add flexibility to these models in situations where the assumption of proportionality does not hold. A Bayesian approach for the estimation of breeding values for herd life traits using Weibull models has been recently described by Ducrocq and Casella (1996) and France and Austria have already adopted these methodologies to estimate official sire proofs for herd life. Canada publishes sire genetic evaluations for herd life based on an index that includes an indirect herd life estimate (based on type) and a direct herd life estimate which is obtained by linear models. The research reported here is the first attempt to utilize survival models for sire evaluation using Canadian data, and may be used to infer whether the methodology to produce official proofs for herd life should be revised.[...
Phenotypic Impact of Conformation Traits on Herd Life Assessed by Survival Analysis
Many farmers believe that selection of dairy cows based on conformation traits will increase herd life indirectly. Although only few type traits have been reported to have significant genetic correlations with herd life traits, conformation still influences the culling decision making process in dairy herds. It is reasonable to assume, for example, that those herds which have their cows classified for type would put some emphasis on conformation when selecting their cows. The Canadian type classification program uses a linear scores system, in which physical characteristics of the cows are actually “measured”. The type scores are posteriorly combined into composite traits (score-card traits), which describe more general aspects of the cow conformation. These composite traits tend to receive more attention than individual scores, because they are easier to interpret, and they probably would be the traits considered by dairymen when making culling decisions.[...