Concentração letal (CL50) do óleo essencial de mentha piperita (lamiaceae) em pirarucus arapaima gigas.

Na piscicultura, diversos produtos fitoterápicos vêm sendo usados no tratamento das parasitoses, principalmente causadas por helmintos. Mentha piperita, planta usada na medicina popular para tratar nauseas, vômitos, indigestão, desordens estomacais, cólicas mestruais e verminoses não tem sido testada em peixes, incluindo pirarucu Arapaima gigas. Porém, é importante conhecer a toxicidade de qualquer produto antes de recomendar a sua concentração terapêutica. Este ensaio realizado no Laboratório de Sanidade de Organismos Aquáticos da Embrapa Amapá, Macapá (AP), teve como objetivo determinar a concentração letal média (CL50-4h) do óleo essencial (OE) de M. piperita para pirarucus. Neste ensaio de toxicidade utilizou-se 168 alevinos de pirarucu (34,7 ± 12,4 g e 16,8 ± 2,0 cm) que após aclimatação foram distribuídos aleatoriamente em 14 tanques com volume para 80 L de água e na densidade de 12 peixes/tanque. O delineamento experimental foi inteiramente casualizado, constituído por dois grupos controles (um somente água do cultivo e outro água do cultivo contendo 80 ?L de álcool etílico absoluto) e seis concentrações (20, 40, 80, 100, 130 e 160 mg/L) de OE de M. piperita em duplicatas. As concentrações do OE foram diluídas em álcool etílico (1g:10 mL). Durante o período de 4 horas de exposição ao OE, os peixes foram mantidos sem alimentação, em sistema estático de água e a CL50-4h, foi calculada usando o método de Trimmed Spearman-Karber. Os resultados mostraram que a CL50-4h de M. piperita foi 38 mg/L, com intervalo de confiança (95%) variando de 30-40 mg/L. Portanto, o teste de toxicidade aguda indica que as concentrações clínicas para banhos terapêuticos de pirarucus com OE de M. piperita devem ser abaixo desses valores obtidos, para evitar mortalidade dos peixes, que é indesejada em qualquer piscicultura durante o tratamento antiparasitário.US100

Back to replacement migration: a new European perspective applying the prospective-age concept

Background: The UN Replacement Migration report (2000) had a significant impact in academic and civil society. Its approach consisted of estimating the migration volumes required to mitigate the effects of population decline and ageing. The volume of migrants required to prevent population decline and sustain the working-age population was not particularly high, but the vast number of migrants needed to maintain the potential support ratio was highlighted as an unrealistic goal. Objective: In this paper the UN exercise is revisited and updated by deploying the concept of prospective age to overcome a strict chronological definition of the working-age population. The replacement migration approach is developed from a new European perspective, the temporal series is extended for an additional decade, and alternative operative age-group definitions are compared by projecting replacement migration estimations according to both classic (conventional) and dynamic (prospective) age limits. Conclusions: The key conclusions of the original UN publication are reasserted. In many countries the replacement migration volumes needed to sustain the decline in total population and working-age population are of an order of magnitude similar to recent observed migration. However, even under the prospective-age approach the halt of the ageing process – expressed as the maintenance of the current potential support ratio – remains an unrealistic target. Contribution: We propose the deployment of the prospective-age concept to define dynamic age limits in the definition of working-age population. Because the prospective-age concept is flexible it will be possible to explore other dimensions from this perspective in the future, increasing the analytical potential of replacement migration estimations as a valuable contribution to the demographic ageing debate.info:eu-repo/semantics/publishedVersio

INFECCIÓN ELEVADA DE Nilonema senticosum EN ADULTOS DE Arapaima gigas CULTIVADOS EN LA AMAZONÍA PERUANA

Ten specimens of paiche Arapaima gigas from a semi-intensive fish farm located in the province of Maynas, Loreto, Peru were examined between June and October 2011 to identify the presence of parasitic helminths. This study identified a high infection of the nematode species Nilomena senticosum. The prevalence was 100% and a mean intensity of 80 parasites per fish.Se colectaron 10 especímenes de paiche Arapaima gigas de un centro de cultivo piscícola semiintensivo de Maynas, Loreto, Perú, entre junio y octubre de 2011, para investigar la presencia de parásitos. Se identificó una alta infección de nematodos de la especie Nilomena senticosum. Se encontró una prevalencia de 100% y una intensidad media de 80 parásitos por pez

Optimization of growth and bacteriocin production by Lactobacillus sakei subsp. sakei 2a

<p><italic>Lactobacillus sakei</italic> subsp. <italic>sakei</italic> 2a is a bacteriocinogenic lactic acid bacterium isolated from Brazilian pork sausage, capable of inhibiting the growth of microbial pathogens, mainly <italic>Listeria monocytogenes</italic>. In order to optimize bacteriocin production for industrial applications, this study evaluated the effect of supplementation of MRS broth with glucose, Tween 20, Tween 80, sodium citrate, potassium chloride and cysteine, and effect of the initial pH and temperature of incubation of the medium on production of bacteriocins by <italic>L. sakei</italic> 2a. Adding glucose and Tween 20 to the medium, an initial pH of 5.0 or 5.5, and incubation temperatures of 25 °C or 30 °C resulted to the highest bacteriocin yields. Thus, a 2⁴ factorial design with the four variables was performed, and statistical analysis showed that it was an adequate model (<italic>R</italic>² = 0.8296). In the studied range, the four parameters significantly influenced bacteriocin production, with the maximum yield produced at an initial pH between 5.5 and 7.0, a temperature between 25 and 30 °C and supplementation of the MRS broth with glucose from 3.25 to 6.0 g L⁻¹ and Tween 20 from 0.575 to 1.15% (v/v). Response Surface Methodology analysis indicated that the highest bacteriocin production (12800 AU mL⁻¹) occurred in the MRS broth supplemented with 5.5 g L⁻¹ glucose and 1.05% Tween 20 at an initial pH of 6.28 and an incubation temperature of 25 °C. The amount of bacteriocin produced in commercial MRS broths under the same conditions was only 5600AU mL⁻¹.</p

Efeitos in vitro da Mentha piperita (Lamiaceae) em Dawestrema spp. (Monogenoidea) e toxicidade aguda em Arapaima gigas (Arapaimidae).

Este estudo avaliou o efeito in vitro do óleo essencial de Mentha piperita L. sobre monogenoideas e sua ação tóxica para Arapaima gigas.AQUACIÊNCIA

Prediction of Dry Matter Intake Based on Ruminal Degradation from Milking Cows Grazing Coast-Cross Grass

Dry matter intake (DMI) of coast-cross grazing by crossbred Holstein-Zebu and Zebu lactating cows was calculated using in vitro dry matter digestibility from extrusa (four esophageal fistulated cows) and fecal output estimate with mordent chromium. Pasture was rotationally grazed with three days grazing period and 27 days resting period, adopting a stocking rate of 1.6 and 3.2 cows/ha, during the dry and rainy season respectively. Voluntary DMI was estimated from degradation characteristics using different equations. Predicted coast-cross DMI varied with models. The prediction of tropical forages dry matter intake from equations based in ruminal degradation parameters needs further investigation before being employed in practice

Antioxidants effects and resistance against pathogens of Colossoma macropomum (Serassalmidae) fed Mentha piperita essential oil.

Immunostimulants in farmed fish diets has been considered an effective approach to health management. This study aimed to assess antioxidant effects and resistance against pathogens of Colossoma macropomum (tambaqui) fed essential oil (EO) of M. piperita at 0%, 0.5%, 1.0% and 1.5% kg&#8722;1 commercial feed during 30 days. Tambaqui were challenged with Aeromonas hydrophila and did not present clinical signs of alterations. Higher hepatic catalase activity was observed in fish fed 1.0% of M. piperita EO, compared with 1.5%. Renal superoxide dismutase and glutathione peroxidase decreased in the fish fed M. piperita EO. Hepatic and renal lipid hydroperoxide increased among fish fed diets with 1.0 and 1.5% of EO. Tambaqui fed 1.0% of M. piperita EO showed respiratory activity increase, compared with 0.5%. Monocytes and PAS-GL were abundant in fish fed higher EO concentrations. Reduction in monogenoideans abundance was observed in fish fed 0.5 and 1.0% of EO. Although anti-helminth effects were observed, M. piperita EO in tambaqui diet did not promote leukocytes and lysozyme activity increases at the concentrations assessed. It can be suggested that other concentrations should be tested in future studies, as the combined use with other products, such as immunostimulants and probiotics