Effects of temperature and delayed initial feeding on the survival and growth of Japanese flounder larvae

The effects of the timing of initial feeding (0, 1, 2 3 and 4 days after yolk exhaustion) and temperature (15, 18 and 21degrees C) on the point-of-no-return (PNR), survival and growth of laboratory-reared Japanese flounder Paralichthys olivaceus larvae were studied under controlled conditions. The larvae reached PNR on 7(.)7, 5(.)2 and 4(.)2 days-post-hatching (dph) at 15, 18 and 2 V C, respectively. At each temperature, larval growth did not differ significantly among the delayed initial feedings 1 day before PNR but decreased significantly in larvae first fed after that. In the treatments where initial feeding was equally delayed, larvae grew significantly faster at 18 and 21degrees C than at 15degrees C. The larvae survived apparently better at 15 and 18degrees C than at 21degrees C when initial feeding was equally delayed. At each temperature, survival of the larvae first fed before PNR did not differ noticeably, while delayed initial feeding after that apparently reduced their survival. These results indicated that there existed a negatively temperature-dependent PNR in the Japanese flounder larvae. Survival and growth of the larvae strongly depended on temperature as well as the timing of initial feeding. High temperature accelerated the yolk exhaustion and growth of the larvae and thus reduced their starvation tolerance and survival. To avoid potential starvation mortality and obtain good growth, the Japanese flounder larvae must establish successful initial feeding within 2 days after yolk exhaustion at 15degrees C and within 1 day at both 18 and 21degrees C. (C) 2005 The Fisheries Society of the British Isles.

Early ontogeny of Ancherythroculter nigrocauda and effects of delayed first feeding on larvae

Development of embryos and larvae in Ancherythroculter nigrocauda Yih et Woo (1964) and effects of delayed first feeding on larvae were observed after artificial fertilization. The fertilized eggs were incubated at an average temperature of 26.5 degrees C (range: 25.7-27) and the larvae reared at temperatures ranging from 21.8 to 28 degrees C. First cleavage was at 50 min, epiboly began at 7 h 5 min, heartbeat reached 72 per min at 24 h 40 min and hatching occurred at 43 h 15 min after insemination. Mean total length of newly hatched larvae was 4.04 +/- 0.03 mm (n = 15). A one-chambered gas bladder was observed at 70 h 50 min, two chambers occurred at 15 days, and scales appeared approximately 30 days after hatching. Larvae began to feed exogenously at day 4 post-hatch at an average temperature of 24 degrees C. Food deprivation resulted in a progressive atrophy of skeletal muscle fibres, deterioration of the larval digestive system and cessation of organ differentiation. Larval growth under food deprivation was significantly affected by the time of first exogenous feeding. Starved larvae began to shrink, with negative growth from day 6 post-hatch. The point of no return (PNR) was reached at day 11 after hatching. Mortality of starved larvae increased sharply from day 12 after hatching.

Effects of delayed first feeding on growth and survival of rock bream Oplegnathus fasciatus larvae

The effects of the timing of first feeding (0, 1 and 2 days after yolk exhaustion) and starvation on the point-of-no-return (PNR), survival and growth of laboratory-reared rock bream larvae were studied under controlled conditions. Larvae began to feed exogenously at 3 days after hatching (dah) and reached PNR on 54 h after yolk exhaustion at 22 +/- 1.5 degrees C. Larvae growth was significantly affected by the time of first exogenous feeding. The growth of 0 day delayed first feeding larvae was obviously faster than those of the other delayed first feeding larvae (P<0.05) whether at 7 dab (SL=3.40 mm, SGR=5.7, CV=4.0) or at 15 dah (SL=4.85 mm, SGR=6.1, CV=8.2) with a more uniform size distribution. Survival of 0 day delayed first feeding larvae and I day delayed first feeding larvae was 13% and 8% at the end of experiment, respectively, while no larvae survived up to 7 dah for 2 days delayed first feeding larvae and unfed larvae. Food resulted in a progressive deterioration of the larval digestive system and atrophy of skeletal muscle fibre. The ratios of head length to SL (standard length), body height to SL and eye diameter to SL were the most sensitive morphometric indices to detect the effects of fasting on larval condition. Present results showed that the combination of morphological and morphometric variables could be used to evaluate the nutritional condition of rock bream larvae. In order to avoid the potential mortality and gain better development, survival and growth in industrial production, the rock bream larvae must establish successful first feeding within 2 days after yolk exhaustion. (C) 2008 Elsevier B.V. All rights reserved.

The influence of initial feeding on muscle development and growth in pacu Piaractus mesopotamicus larvae

The effects of different feeding schemes on pacu Piaractus mesopotamicus early development were evaluated with respect to growth, survival, muscle development, and differential gene expression of MyoD and myogenin. The pacu larvae (4 days post hatch-dph, 0.77 mg wet weight) were given six feeding treatments intentionally designed to cause variations in the larvae growth rate: (A) only artemia nauplii; (CD) only a commercial diet; (ED) only a semi-purified experimental diet; (ACD) and (AED) two treatments that involved weaning; and (S) starvation. Early weaning from artemia nauplii to the formulated diets (ACD and AED) affected growth and survival of the pacu larvae compared with the exclusive use of artemia (A). Starvation (S) and the commercial diet (CD) caused total mortality in pacu larvae at 18 dph. The experimental diet (ED) assured low fish survival and growth. The skeletal muscle morphology was not affected by the delay in somatic growth from early weaning onto the formulated diets. Three distinct muscle compartments were observed throughout the larval development in treatments A, ACD and AED: superficial, deep and intermediate, accompanied by muscle thickening. Severe undernourishment caused drastic differences in growth and in the morphology of the muscle fibers. Pacu larvae fed only formulated diets (CD and ED) showed muscle characteristics similar to the larvae in starvation (S) during the first 15 dph. At 27 and 35 dph, a slight increase in epaxial muscle mass was noted in larvae fed only the experimental diet (ED). At 35 dph, we observed a high frequency of fibers >= 40 mu m in the larvae that were weaned onto the formulated diets (ACD and AED), indicative of hypertrophy. In contrast, the larvae fed only artemia nauplii (A) displayed a larger number of fibers with diameters <= 20 mu m, which is indicative of hyperplasia. The expression of the MyoD and myogenin genes in pacu larvae at 35 dph was not affected by initial feeding (p>0.05). In conclusion, the formulated diets used impaired pacu larvae growth and survival; therefore, they were inadequate for pacu, at least at the times they were introduced. Artemia nauplii were the most adequate food source during first feeding of the pacu, and they produced bigger fish upon completion of the experiment. Moreover, the contribution of hyperplasia to the skeletal muscle growth appeared higher in fast- than in slow-growing pacu larvae. (C) 2011 Elsevier By. All rights reserved.

Feeding, morphological changes and allometric growth during starvation in miiuy croaker larvae

We investigated the effects of the timing of first feeding (larvae in F0, F1, F2, F3 and S were first fed on day 3, 4, 5, 6 days after hatching (DAH) and unfed, respectively) on feeding, morphological changes, survival and growth in miiuy croaker larvae at 24A degrees C. The fed larvae initiated feeding on 3 DAH and reached point of no return (PNR) on 6 DAH. Larvae in F0 and F1 groups survived apparently better than F2 group at the end of the experiment on 36 DAH. High larval mortality occurred from 3 to 7 DAH in all feeding groups, accounting for 40% (F0, F1 and F2 groups) to 90% (F3 and S groups) of the total mortality. Larvae in F0 and F1 groups grew better than F2 group throughout the experiment. Eye diameter, body height, head height and mouth gape of the first feeding larvae were more sensitive to starvation than other morphometrics and could be used as indicators for evaluating their nutritional status. Results indicated that delayed first feeding over 1 day after yolk exhaustion could lead to poor larval survival and growth. To avoid starvation and obtain good growth in culturing, larvae feeding should be initiated within 1 day after yolk exhaustion at 24A degrees C.

Colonization and osteogenic differentiation of different stem cell sources on electrospun nanofiber meshes

Numerous challenges remain in the successful clinical translation of cell-based therapies for musculoskeletal tissue repair, including the identification of an appropriate cell source and a viable cell delivery system. The aim of this study was to investigate the attachment, colonization, and osteogenic differentiation of two stem cell types, human mesenchymal stem cells (hMSCs) and human amniotic fluid stem (hAFS) cells, on electrospun nanofiber meshes. We demonstrate that nanofiber meshes are able to support these cell functions robustly, with both cell types demonstrating strong osteogenic potential. Differences in the kinetics of osteogenic differentiation were observed between hMSCs and hAFS cells, with the hAFS cells displaying a delayed alkaline phosphatase peak, but elevated mineral deposition, compared to hMSCs. We also compared the cell behavior on nanofiber meshes to that on tissue culture plastic, and observed that there is delayed initial attachment and proliferation on meshes, but enhanced mineralization at a later time point. Finally, cell-seeded nanofiber meshes were found to be effective in colonizing three-dimensional scaffolds in an in vitro system. This study provides support for the use of the nanofiber mesh as a model surface for cell culture in vitro, and a cell delivery vehicle for the repair of bone defects in vivo.

Use of water-miscible retinyl palmitate as markers of chylomicrons gives earlier peak response of plasma retinyl esters compared with oil-soluble retinyl palmitate

Delayed peak response of plasma retinyl esters (RE) relative to plasma triacylglycerols (TAG) and apolipoprotein (Apo) B-48 responses following a fat load supplemented with vitamin A raised doubts about the use of vitamin A to label dietary-derived lipids and lipoproteins. The present study compared the use of water-miscible and oil-soluble retinyl palmitate (RP) as markers of dietary-derived lipoproteins in healthy subjects along with the measurements of postprandial plasma TAG and ApoB-48 responses to investigate whether the delayed peak response observed was due to delayed intestinal output of RE from oil-based solutions. Nine healthy female subjects were given a standard test meal containing a dose (112 mg) of RP in either water-miscible or oil-soluble form in random order, on two separate occasions after a 12 h overnight fast. The results showed that the mean plasma RE concentrations reached a peak significantly later than mean plasma TAG and ApoB-48 concentrations when oil-soluble RP was consumed, whereas plasma RE peaked earlier relative to plasma TAG and ApoB-48 responses when water-miscible RP was used. The results suggested a more rapid absorption with a significantly higher and earlier peak response of plasma RE when water-miscible RP was consumed. This was in contrast to the delayed initial appearance and later sustained higher concentrations of plasma RE during the late postprandial period when oil-soluble RP was consumed. The RE response to the water-miscible RP showed better concordance with plasma TAG response than that of oil-soluble RP.

Utilização de embriões liofilizados e flocos de Artemia na diversificação nutricional de pós-larvas do camarão marinho Litopenaes vannamei (Boone, 1931)

The objective of the current study was to evaluate the zootechnical performance (survival and growth) of Litopenaeus vannamei post-Iarvae fed an artificial shrimp diet supplemented with Artemia flakes or freeze-dried Artemia embryos. For that purpose, 20 culturing units were individually stocked with 50 shrimp post-Iarvae (average dry weight of 0,3 ± 0,03 mg) at a stocking density of 20 post-larvae per liter, and fed the experimental diets to satiation during 20 days. The experimental design consisted of four diets (T1, T2, T3 and T4) with five repetitions each. For treatments T1, T2 and T3, dietary supplements of 5mg of Artemia flakes (T1), freeze-dried Artemia embryos (T2), and of the commercial shrimp diet (T3) were offered 2 hours after the shrimp were initially fed the commercial shrimp diet. For treatment T4 (control), no additive was offered 2 hours after the initial feeding. Shrimp survival, absolut (GPA) and relative increase in weight (GPR), and specific growth rate (TCR) were used as evaluation criteria. After the experimental period, no significant statistical differences (p>0,05) in survival were observed. Regarding growth, the dietary treatment which used freeze-dried Artemia embryos as an additive (T2) presented the best results for GPA (6,7 ± 0,7 mg). There were no statistical differences within treatments T1, T3 and T4 (p>0,05). AIso, post-larvae fed freeze-dried embryos (T2) showed a relative increase in weight (2241,4%) which differed significantly (p<0,05) from T4(1911,7%) but not from T1 (1801,6%) or T3 (1946,7%). In conclusion, the results of the current study indicate that an artificial shrimp diet supplemented with freeze-dried Artemia embryos fulfils the nutritional requirements of post-larvae L. vannamei and promotes a better growth than diets not supplemented with Artemia flakes

Política de formação profissional do SENAI e a qualidade de vida no trabalho: o olhar dos egressos

Este estudo apresenta uma pesquisa em que se discute a política de formação profissional do SENAI-PA, a partir dos depoimentos de egressos de cursos na área de aprendizagem industrial, da instituição, cujo direcionamento teórico baseia-se na Qualidade de Vida do Trabalho. Teoricamente, consideramos a influência da Teoria do Capital Humano e os indicadores de QVT, destacadamente o econômico, o político, o psicológico e o sociológico na formação de aprendizes industriais. A questão central foi responder como a formação profissional obtida pelos egressos do SENAI refletiu na sua qualidade de vida no trabalho. Entre os objetivos de ordem geral e específicos, destacam-se, desenvolver um estudo sobre a situação dos egressos dos cursos do SENAI do Centro de Formação Profissional Getúlio Vargas em Belém-PA, no período de 2000 a 2003; identificar os egressos do Curso de Aprendizagem Industrial; verificar a inserção no campo profissional desses egressos; analisar as expectativas profissionais e sócio-econômicas dos egressos com base nos indicadores de QVT e contribuir para o aprofundamento dos processos de avaliação institucional do Centro de Formação Profissional, no intuito de sintonizar a atuação estratégica do SENAI com os anseios e necessidades da comunidade. Os depoimentos objetos de nosso estudo foram obtidos em entrevistas com ex-alunos, nos quais as falas revelam a importância dada por eles ao profissionalismo, à obtenção de renda a partir dessa profissão e dos necessários aperfeiçoamentos profissionais, em face à acirrada disputa no mercado de força de trabalho, na conjuntura sócio-econômica globalizada contemporânea. Para além disso, este trabalho possibilita também uma reflexão histórica sobre a evolução do SENAI, destacado integrante do Sistema S e percussor de políticas de educação profissional no Brasil, oriundas da fase inicial tardia da industrialização brasileira. Na análise, procuramos ainda revelar aspectos fundamentais que devem ser perseguidos pelas políticas públicas - em especial as relativas à educação profissional com todos os entes executores dessa política, quer públicos ou privados -, em termos de adequação de suas diretrizes em prol de uma formação profissional para as pessoas mais necessitadas que atenda as necessidade de um padrão de Qualidade de Vida, equivalente aos parâmetros mundiais.

Lecithotrophic behaviour in zoea and megalopa larvae of the ghost shrimp Lepidophthalmus siriboia Felder and Rodrigues, 1993 (Decapoda: Callianassidae)

A alimentação é considerada crítica em cultivo de larvas de decápodes. No entanto, algumas espécies podem apresentar reservas nutritivas suficientes para completar o desenvolvimento larval sem a necessidade de alimentação externa (conhecido como desenvolvimento larval lecitotrófico). No presente estudo, dois experimentos foram realizados para verificar se o callianassídeo Lepidophthalmus siriboia tem comportamento lecitotrófico ou se precisa de alimento externo para completar o desenvolvimento larval: Experimento 1, larvas submetidas a um período inicial de alimentação e, Experimento 2, larvas submetidas a um período inicial de inanição. Em ambos os experimentos, observou-se altas taxas de sobrevivência, com apenas 2 megalopas e 1 zoea III mortos. Estes resultados sugerem fortemente que larvas de L. siriboia são lecitotróficas, tendo reservas suficientes para completar o desenvolvimento larval, enquanto o estágio de megalopa apresenta lecitotrofia facultativa. Os períodos larvais de cada estágio nos tratamentos foram bastante semelhantes. No entanto, foram observadas algumas diferenças significantes entre alguns períodos, os quais podem estar relacionados às condições de cultivo, provavelmente devido a fatores abióticos, à variabilidade individual da condição larval, ou ainda a fatores como estresse causado às fêmeas ovígeras durante embriogênese.

Complicated intra-abdominal infections in Europe: a comprehensive review of the CIAO study

The CIAO Study ("Complicated Intra-Abdominal infection Observational" Study) is a multicenter investigation performed in 68 medical institutions throughout Europe over the course of a 6-month observational period (January-June 2012).Patients with either community-acquired or healthcare-associated complicated intra-abdominal infections (IAIs) were included in the study.2,152 patients with a mean age of 53.8 years (range: 4-98 years) were enrolled in the study. 46.3% of the patients were women and 53.7% were men. Intraperitoneal specimens were collected from 62.2% of the enrolled patients, and from these samples, a variety of microorganisms were collectively identified.The overall mortality rate was 7.5% (163/2.152).According to multivariate analysis of the compiled data, several criteria were found to be independent variables predictive of patient mortality, including patient age, the presence of an intestinal non-appendicular source of infection (colonic non-diverticular perforation, complicated diverticulitis, small bowel perforation), a delayed initial intervention (a delay exceeding 24 hours), sepsis and septic shock in the immediate post-operative period, and ICU admission.Given the sweeping geographical distribution of the participating medical centers, the CIAO Study gives an accurate description of the epidemiological, clinical, microbiological, and treatment profiles of complicated intra-abdominal infections (IAIs) throughout Europe.

Development of an animal repellent - selection, efficacy and presentation

Under some circumstances it may be desirable to repel herbivorous pests (e. g. goats and wallabies) from plants (e. g. horticultural or forestry seedlings) rather than to kill them. These circumstances may include using these animals as a resource at a later time, and there may also be welfare, public perception or legislative issues where repelling animals from particular plants or area is preferable to killing them. The first experiment tested the efficacy of 5 different materials (tiger fecal extract, maggot brew-the liquid exudate from a flyblown goat, capsaicin, dog urine, and burnt goat hair, skin and carcass+fat) to repel groups of goats in a feedlot pen from 1 trough of feed when another trough of feed was available to them to eat. Each repellent was tested on 5 groups of mixed age female goats for periods of 3 days. All 5 groups were exposed to the 5 repellents. Both tiger fecal extract and maggot brew reduced intake of feed from the 'protected' feed trough and significantly (P < 0.05) delayed 'normal' feeding behaviour by more than 5 h from that trough. The repellents became less effective with repeated use even with different groups of goats. The reduction in effectiveness was indicated by higher intakes of feed and earlier feeding from the protected trough. This habituation to the repellents, where the effectiveness is reduced with repeated exposure, is of concern. In the second experiment, we selected the most effective repellent (tiger fecal extract) and tested its efficacy under similar conditions, after the repellent had been mixed with a carrier (bentonite) in an endeavour to increase the duration of its effectiveness. This repellent was significantly more effective in repelling groups of 3 goats in a feedlot pen from 1 trough of feed for 3 days, when another trough of feed was available to them to eat.

Utilização de embriões liofilizados e flocos de Artemia na diversificação nutricional de pós-larvas do camarão marinho Litopenaes vannamei (Boone, 1931)

The objective of the current study was to evaluate the zootechnical performance (survival and growth) of Litopenaeus vannamei post-Iarvae fed an artificial shrimp diet supplemented with Artemia flakes or freeze-dried Artemia embryos. For that purpose, 20 culturing units were individually stocked with 50 shrimp post-Iarvae (average dry weight of 0,3 ± 0,03 mg) at a stocking density of 20 post-larvae per liter, and fed the experimental diets to satiation during 20 days. The experimental design consisted of four diets (T1, T2, T3 and T4) with five repetitions each. For treatments T1, T2 and T3, dietary supplements of 5mg of Artemia flakes (T1), freeze-dried Artemia embryos (T2), and of the commercial shrimp diet (T3) were offered 2 hours after the shrimp were initially fed the commercial shrimp diet. For treatment T4 (control), no additive was offered 2 hours after the initial feeding. Shrimp survival, absolut (GPA) and relative increase in weight (GPR), and specific growth rate (TCR) were used as evaluation criteria. After the experimental period, no significant statistical differences (p>0,05) in survival were observed. Regarding growth, the dietary treatment which used freeze-dried Artemia embryos as an additive (T2) presented the best results for GPA (6,7 ± 0,7 mg). There were no statistical differences within treatments T1, T3 and T4 (p>0,05). AIso, post-larvae fed freeze-dried embryos (T2) showed a relative increase in weight (2241,4%) which differed significantly (p<0,05) from T4(1911,7%) but not from T1 (1801,6%) or T3 (1946,7%). In conclusion, the results of the current study indicate that an artificial shrimp diet supplemented with freeze-dried Artemia embryos fulfils the nutritional requirements of post-larvae L. vannamei and promotes a better growth than diets not supplemented with Artemia flakes

Utilização de embriões liofilizados e flocos de Artemia na diversificação nutricional de pós-larvas do camarão marinho Litopenaes vannamei (Boone, 1931)

The objective of the current study was to evaluate the zootechnical performance (survival and growth) of Litopenaeus vannamei post-Iarvae fed an artificial shrimp diet supplemented with Artemia flakes or freeze-dried Artemia embryos. For that purpose, 20 culturing units were individually stocked with 50 shrimp post-Iarvae (average dry weight of 0,3 ± 0,03 mg) at a stocking density of 20 post-larvae per liter, and fed the experimental diets to satiation during 20 days. The experimental design consisted of four diets (T1, T2, T3 and T4) with five repetitions each. For treatments T1, T2 and T3, dietary supplements of 5mg of Artemia flakes (T1), freeze-dried Artemia embryos (T2), and of the commercial shrimp diet (T3) were offered 2 hours after the shrimp were initially fed the commercial shrimp diet. For treatment T4 (control), no additive was offered 2 hours after the initial feeding. Shrimp survival, absolut (GPA) and relative increase in weight (GPR), and specific growth rate (TCR) were used as evaluation criteria. After the experimental period, no significant statistical differences (p>0,05) in survival were observed. Regarding growth, the dietary treatment which used freeze-dried Artemia embryos as an additive (T2) presented the best results for GPA (6,7 ± 0,7 mg). There were no statistical differences within treatments T1, T3 and T4 (p>0,05). AIso, post-larvae fed freeze-dried embryos (T2) showed a relative increase in weight (2241,4%) which differed significantly (p<0,05) from T4(1911,7%) but not from T1 (1801,6%) or T3 (1946,7%). In conclusion, the results of the current study indicate that an artificial shrimp diet supplemented with freeze-dried Artemia embryos fulfils the nutritional requirements of post-larvae L. vannamei and promotes a better growth than diets not supplemented with Artemia flakes