As denture cleansers should be able to reduce biofilm accumulation without changing the acrylic resin surface structure, this study evaluated the effect of denture cleansers on surface roughness of acrylic resin and on biofilm accumulation. It was conducted a crossover study of three phases of 4 days each and 13 volunteers wore palatal appliances containing four specimens of acrylic resin of known surface roughness which were extra-orally submitted once a day to three groups of separated treatments: (i) negative control, (ii) enzymatic commercial solution (Ortoform) or (iii) 0.5% sodium hypochlorite (NaOCl). The appliances were immersed eight times a day in a 20% sucrose solution to enhance biofilm formation. On morning of the fifth day of each phase, the amount of biofilm formed on the specimens was estimated by the amount of protein extracted with alkali and the surface roughness of the specimens was again measured. New palatal appliances with new specimens were worn by the volunteers in the following phases, but the treatments were changed. The roughness of the resin increased after the treatments (P < 0.05) but the difference among the cleansers was not statistically significant (P = 0.85). The lowest amount of biofilm formed on acrylic resin specimens was found for the treatment with NaOCl (P < 0.05) but the enzymatic product did not differ from the negative control group (P > 0.05). The data suggest that the roughness of acrylic resin was not changed by the cleansers, but the ability to reduce biofilm accumulation depended on the product used.

Sunflower (Helianthus annuus L.) is an allogamic plant, which needs insects on flowering, especially the honeybees for seed production. Collecting nectar and pollen by honeybees in agricultural crops is essential to apiculture, as well as a better understanding of plant biology. The foraging behavior of Africanized Apis mellifera L. (Hymenoptera, Apidae) and its efficiency of pollination on seed yield of sunflower genotypes (open pollination and restricted pollination) were evaluated. There were peaks of visits by A. mellifera for nectar collection on the 2 nd and 3 rd flowering days between 7h00 and 8h30. The average density of A. mellifera during increased visitation ranged from 2.27 to 2.94 bees per capitulum. Nectar collecting bees were more frequent (2.28 bees per capitulum) than pollen collecting (0.40 bees per capitulum). On the 3 rd flowering day, Helio 360 and Aguará hybrids had higher (p ≤ 0.05) number of bee visits per flower head than the other genotypes. Seed yield was 43 % higher (p ≤ 0.05) from sunflower plants that were visited by pollinator-insects compared with plants restricted to pollinators.

This study aimed to develop a Geographic Information System (GIS), for storage of information and geographic location of apiaries in eight counties in western Paraná; study the local flora; the land used; and the honey productivity in the harvest of 2010 in two of these areas: Marechal Cândido Rondon and Santa Helena. In order to do so we used the software SPRING, delimiting a radius of action of bees of three kilometers around the apiaries. We interviewed and registered 126 beekeepers with 383 apiaries. By using the images we selected areas with greater and lower overlap of hives in Marechal Cândido Rondon (144 and 44 hives, respectively) and Santa Helena (165 and 40 hives, respectively), in a three kilometers radius, selecting 15 colonies in each area, for the study of the parameters cited. In the multivariate analysis of the grouping, five groups were formed, by their similarity of management, indicating the higher average production in the hives of the most populated area of Santa Helena and lower average production in the most populated of Marechal Cândido Rondon. The grouping of hives, the differences in the production of honey and floristic survey indicated that these differences could be associated with management, floristic and climatic differences recorded in the period of production, in the areas studied.

Phenotypic characters of honeybees, relevant to beekeepers, can be evaluated by studying correlations between them, and the correlated characteristics can be evaluated in the short term to assist in monitoring of annual genetic progress. This work therefore aims to evaluate the production of honey and propolis, the hygiene and defensive behaviours of two generations of Africanized Apis mellifera (Hymenoptera, Apidae), to estimate the correlations between them and their heritability. We used 30 Langstroth beehives in apiaries in Marechal Cândido Rondon, Paraná State, Brazil. We used a method of drilling pupae to evaluate hygiene behaviour and the velveteen ball method to test defensive behaviour. We selected ten colonies which had the best honey and propolis production, and which produced F1 queens that were then transferred to beehives at an experimental farm, in order to observe honey and propolis production, hygiene and defence behaviours of their female offspring. The estimated differences for each characteristic between the generations, the correlations between them within each generation and their heritability suggest that selection of colonies based on propolis production was more efficient at maintaining this high production than was selection based on honey production according to the performance of the colonies for this characteristic. The selected behavioural characteristics can be used to enhance performance, but not for improving yield characteristics evaluated.

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Human listeriosis is a severe foodborne disease caused by Listeria monocytogenes. It is a zoonosis that represents a significant concern for the food industry due to the high mortality rate it causes and the fact that the organism is capable of growing at refrigeration temperatures. Dairy products and ready-to-eat meats are among the foods most often involved in listeriosis outbreaks. Listeria is a common contaminant in the dairy environment, both on the farm and in the processing plant. The main sources of L. monocytogenes in dairy farms are manure and improperly fermented silage. If silage crops are grown on contaminated land, a new cycle of silage contamination and faecal shedding by ruminants that consume such silage may ensue. High loads of L. monocytogenes produced in farm environments may thus represent a primary source for the introduction of this pathogen into the human food supply chain; dairy cows would represent a reservoir for the bacterium, and raw milk and beef would represent the main vehicles for its transmission from dairy farms to humans. Even if contamination originates in post-processing environments, contaminated raw foods may still represent a vehicle for introducing L. monocytogenes into food processing plants. Molecular typing methods have confirmed that common strains of L. monocytogenes are present in dairy farm-associated isolates and isolates from both human epidemic and sporadic cases. Pre-harvest (on-farm) control of listeriosis should be based mainly on the control of manure, silage, herd health and milking practices.Additional key words: animal reservoir; dairy primary production; environmental sources; food vehicles; listeriosis. ResumenRevisión. Tipos de gestión y producción de las granjas de ganado vacuno lechero relacionados con la presencia de Listeria monocytogenes en la leche y la carne La listeriosis humana es una grave enfermedad transmitida por alimentos y causada por Listeria monocytogenes. Se trata de una zoonosis que supone una gran preocupación para la industria alimentaria debido a su alta tasa de mortalidad y al hecho de que el microorganismo es capaz de crecer a temperaturas de refrigeración. Listeria es un contaminante habitual en las granjas y plantas de productos lácteos. En las granjas las fuentes principales de L. monocytogenes son el estiércol y los ensilados mal fermentados. Si la cosecha utilizada para producir ensilados procede de campos contaminados, puede comenzar un nuevo ciclo de contaminación de los ensilados y liberación del patógeno en las heces de los animales. El ganado vacuno lechero representa uno de los principales reservorios de este microorganismo y la leche y la carne representarían los principales vehículos para su transmisión desde la granja de producción de leche al ser humano. Incluso cuando la contaminación del alimento procede de etapas posteriores al procesado, los alimentos crudos contaminados también representan uno de los vehículos de entrada de L. monocytogenes en las plan-

Dentofacial morphology may affect orofacial functions, therefore the aim of the current study was to evaluate the influence of craniofacial morphology on masticatory function, occlusal contact area (OCA), and masticatory muscles activity. Seventy-eight (78) subjects were divided into three groups according to vertical facial pattern: 1. mesofacial; 2. brachyfacial; and 3. dolichofacial. Artificial material and the sieving method were used to access masticatory efficiency (ME). OCA was determined by registration of posterior teeth. Electromyographic (EMG) activity of the masseter and anterior temporal (AT) muscles was accessed bilaterally at rest and at maximal vertical clenching (MVC). ME (%) was significantly higher in brachyfacial and lower in dolichofacial subjects. Brachyfacials presented the highest OCA (mm2) followed by meso and dolichofacial subjects. The EMG of the masseter and AT at rest and at MVC showed that dolichofacial subjects presented the lowest activity values, while brachyfacial subjects presented significantly higher measurements. Craniofacial morphology affected masticatory function, OCA, and EMG activity of the masticatory muscles.