SABIIA - Sistema Aberto e Integrado de Informação em Agricultura (Sabiia)

Vanhaecke, P.; Sorgeloos, P..

The effect of temperature on different geographical strains of Artemia has been studied for the following criteria: the hatchability of the cysts, the resistance of the larvae to high temperature (34°C) and the biomass production of larvae cultured under standard conditions. Experimental temperatures ranged from 25° to 37°C for the hatching criteria and from 20° to 32.5°C for the biomass production.Both the hatching percentage and growth performance are affected by temperature. However, the relative and quantitative impact of temperature varies widely among Artemia strains. This is also the case for the temperature resistance of the larvae. The impact of increasing temperatures on cyst hatching as well as the...

Effect of dietary essential fatty acids on egg quality and larviculture success of the greasy grouper (Epinephelus tauvina F.): preliminary results

Palavras-chave: Aquaculture techniques; Biomass; Brine shrimp culture; Growth; Larvae; Survival; Temperature effects; Artemia.

Ano: 1989

URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=3194

Dhert, P.; Lim, L.C.; Lavens, P.; Chao, T.M.; Chou, R.; Sorgeloos, P..

In spite of its aquaculture potential, the larval rearing of greasy grouper (Epinephelus tauvina) remains problematic and is not yet commercially feasible. The low and unpredictable larval survival is due to difficulties encountered in spawning the broodstock, the small size of the larvae at first feeding, and the high sensitivity of the larvae until day 45. The nutritional requirements for the broodstock as well as for the young larvae are still enigmatical. In this presentation the impact of supplementing the highly unsaturated fatty acids (HUFA), eicosapentaenoic (EPA), and docosahexaenoic acid (DHA) to the broodstock and larval diets is illustrated.

International study on Artemia: 14. Growth and survival of Artemia larvae of different geographical origin in a standard culture test

Palavras-chave: Diets; Fatty acids; Fish culture; Fish eggs; Fish larvae; Nutritional requirements; Survival.

Ano: 1991

URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=2852

Vanhaecke, P.; Sorgeloos, P..

For characterization of strains of the brine shrimp Artemia of different geographical origin, a standard culture test has been developed in order to compare statistically growth and survival of larvae of different strains. 25 geographical strains have been studied so far -including, for 3 strains, analyses of cysts harvested at different times. Important differences in rates of growth and survival were observed between strains but not among batches of the same strain. Best performances were noted for strains from Bahia Salinas (Puerto Rico), Buenos Aires (Argentina), Chaplin Lake (Canada), Great Salt Lake (Utah, USA), Galera Zamba and Manaure (Colombia).

The effect of HUFA and vitamin C-enriched rotifers on larval growth and survival of grouper (Epinephelus suillus)

Palavras-chave: Aquaculture; Growth; Larvae; Survival; Artemia.

Ano: 1980

URL: http://www.vliz.be/imisdocs/publications/261892.pdf

Chavez, D.R.; Estenor, D.G.; Merchie, G.; Lavens, P..

Newly-hatched grouper larvae were reared for 24 days at a density of 15 larvae.l-1 in 250-l capacity cylindro-conical tanks filled with 200l seawater. Starting day 2, the larvae were given: Chlorella-fed rotifers (Chl-R) rotifers fed Culture Selco (INVE Aquaculture NV, Belgium) (CS-R), and rotifers fed Culture Selco and consequently enriched for 24h with 20% vitamin C (CSC-R). The rotifer density in the larval tanks was maintained at 15 rotifers.ml-1. The rotifer diet was supplemented with egg yolk until day 5. Each treatment had five replicates. Preliminary results show no significant difference in the survival rate of grouper larvae given Chl-R (4.21±2.8%), CS-R (2.56±0.9%) and CSC-R...

Search for beneficial bacterial strains for turbot (Scophthalmus maximus L.) larviculture

Palavras-chave: Fatty acids; Feeding experiments; Growth; Larvae; Survival; Vitamin C; Chlorella; Epinephelus suillus; Rotifera.

Ano: 1995

URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=2537

Huys, L.; Dhert, P.; Robles, R.; Ollevier, F.P.; Sorgeloos, P.; Swings, J..

The aerobic bacterial flora in the gut of turbot larvae and their influence on larval survival was examined. Two turbot experiments were run with six replicates each time. Large variation, from 0% up to 44%, was observed in the survival percentage of turbot larvae. There was no correlation between the number of bacteria present in the gut of turbot larvae and the larval survival rate. During both experiments, all replicates followed nearly the same rate of bacterial development in the gut of turbot larvae going from circa 102 CFU larva-1 just before first feeding at day 3 post hatch to 105 CFU larva-1 at day 9 post hatch.In total, 127 bacterial isolates from 12...

International study on Artemia : 32. Combined effects of temperature and salinity on the survival of Artemia of various geographical origin

Palavras-chave: Aerobic bacteria; Aquaculture; Commensals; Digestive system; Fish culture; Fish larvae; Gastrointestinal tract; Microorganisms; Rearing; Scophthalmus maximus; Survival; Bacteria; Scophthalmus maximus; Vibrio mediterranei.

Ano: 2001

URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=5720

Vanhaecke, P.; Siddall, S.E.; Sorgeloos, P..

The brine shrimp inhabits geographically isolated biotopes with specific biotic and abiotic conditions. This has resulted in various geographical strains between which marked genetica, biological and chemical differentiation exists. The response of 13 different Artemia strains to the combined effect of temperature and salinity has been studied. Experimental temperatures tested ranged from 18 to 34°C and salinities from 5 to 120 promille. Except for Chaplin Lake (Canada) Artemia , all strains showed high survival over a wide range of salinities (35-110 promille). For all strains the common temperature optimum was between 20 and 25°C. Interaction between temperature and salinity was negligible or very limited....

Comparison of phosphatidylcholine purified from soybean and marine fish roe in the diet of postlarval Penaeus vannamei Boone

Palavras-chave: Salinity effects; Survival; Temperature effects; Artemia.

Ano: 1984

URL: http://www.vliz.be/imisdocs/publications/261924.pdf

Coutteau, P.; Kontara, E.K.M.; Sorgeloos, P..

The effects of adding two different types of phosphatidylcholine (PC) (purified from soybean lecithin, SPC, or marine fish roe, MPC) on growth, survival and osmotic stress resistance as well as lipid and fatty acid composition of postlarval Penaeus vannamei was determined. PC was added at a level of 1.5% in a semi-purified diet containing similar levels of essential fatty acids (EFA). A PC-free diet served as the control treatment. The supplementation of 1.5% SPC significantly improved growth and reduced sensitivity to osmotic stress. P. vannamei-fed MPC showed inferior growth compared to those fed SPC, but yielded better growth and survival than the PC-deprived shrimp. The addition of any of the PC types resulted in a...

Microbial control of the culture of Artemia juveniles through preemptive colonization by selected bacterial strains

Palavras-chave: Animal nutrition; Complex lipids; Diets; Feeding experiments; Lipids; Neurotransmitters; Polyunsaturated fatty acids; Shrimp culture; Survival; Litopenaeus vannamei; Penaeus vannamei.

Ano: 2000

URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=37

Verschuere, L.; Rombaut, G.; Huys, G.; Dhont, J.; Sorgeloos, P.; Verstraete, W..

The use of juvenile Artemia as feed in aquaculture and in the pet shop industry has been getting more attention during the last decade. In this study, the use of selected bacterial strains to improve the nutritional value of dry food for Artemia juveniles and to obtain control of the associated microbial community was examined. Nine bacterial strains were selected based on their positive effects on survival and/or growth of Artemia juveniles under monoxenic culture conditions, while other strains caused no significant effect, significantly lower rates of survival and/or growth, or even total mortality of the Artemia . The nine selected strains were used to preemptively colonize the...

Longevity of Horseweed Seed Bank Depending on the Burial Depth

Palavras-chave: Aquaculture; Biological control; Brine shrimp culture; Chemotaxonomy; Colonization; Feeds; Interspecific relationships; Nutrition; Polyculture; Survival; Artemia.

Ano: 1999

URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=4039

Planta Daninha

VARGAS,A.A.M.; AGOSTINETTO,D.; ZANDONÁ,R.R.; FRAGA,D.S.; AVILA NETO,R.C..

ABSTRACT: Horseweed (Conyza spp.) is considered as one of the major weeds occurring in the agricultural areas of South America, especially in Brazil. This species stands out from the other weeds due to characteristics such as large seed production, continued seed production, dispersion over long distances and resistance to 5-enolpyruvoylshikimate 3-phosphate (EPSP) and acetolactate synthase (ALS) inhibiting herbicides, features that increase their management. Therefore, this study aimed at determining the physiological quality and longevity of horseweed seeds over 12 months. The experiment was established under field conditions, using a randomized block design with four replications. Fifty horseweed seeds were distributed into 50 g of dry soil, placed in...

Palavras-chave: Conyza spp.; Survival; Dormancy; Germination; Viability.

Ano: 2018

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-83582018000100249

A Theory of Firm Decline

Gian Luca, Clementi; Cooley, Thomas; Di Giannatale, Sonia.

We study the problem of an investor that buys an equity stake in an entrepreneurial venture, under the assumption that the former cannot monitor the latter’s operations. The dynamics implied by the optimal incentive scheme is rich and quite different from that induced by other models of repeated moral hazard. In particular, our framework generates a rationale for firm decline. As young firms accumulate capital, the claims of both investor (outside equity) and entrepreneur (inside equity) increase. At some juncture, however, even as the latter keeps on growing, invested capital and firm value start declining and so does the value of outside equity. The reason is that incentive provision is costlier the wealthier the entrepreneur (the greater is inside...

Tipo: Working or Discussion Paper

Palavras-chave: Principal Agent; Moral Hazard; Hidden Action; Incentives; Survival; Firm Dynamics; Financial Economics; D82; D86; D92; G32.

Ano: 2010

URL: http://purl.umn.edu/92788

The Impact of Trade Costs on Firm Entry, Exporting, and Survival in Korea

Kim, Sooil; Reimer, Jeffrey J.; Gopinath, Munisamy.

This study uses a unique firm-level dataset to examine how falling trade costs from 1993-2001 affected entry, exit, productivity, and exporting in the Korean manufacturing sector. We verify many of the predictions of recent heterogeneous-firm models of international trade. For example, falling trade costs reduced entry by new Korean firms, increased their probability of exit, and reduced the market share of surviving firms. We also find that small firms had a particularly high level of dynamism over the sample period. Small firms were more likely to enter and exit, and marginally more likely to gain market share, enter export markets for the first time, and improve their productivity.

Tipo: Conference Paper or Presentation

Palavras-chave: Employment; Exit; Exports; Firm deaths; Survival; Trade costs; Agribusiness; Industrial Organization; International Development; International Relations/Trade; Labor and Human Capital; Marketing; Production Economics; Productivity Analysis; Research and Development/Tech Change/Emerging Technologies; F10; D24.

Ano: 2009

URL: http://purl.umn.edu/49185

Do Government Payments Influence Farm Size and Survival?

Key, Nigel D.; Roberts, Michael J..

Using farm-level data from the 1987, 1992, and 1997 Census of Agriculture, this study estimates what effect agricultural payments have had on the likelihood of farm business survival and on farm size. The unique panel data set permits conditioning current farm size on past farm size, which removes much of the individual heterogeneity of farms that could be spuriously correlated with payment levels. Results indicate that between consecutive censuses, past per acre payments have a significant positive effect on farm business survival and a small yet significant influence on the size of continuing farms.

Tipo: Journal Article

Palavras-chave: Agricultural payments; Exit rate; Farm size; Growth; Payment limits; Survival; Agricultural and Food Policy; Agricultural Finance; Farm Management.

Ano: 2007

URL: http://purl.umn.edu/8645

Why Do Rural Firms Live Longer?

Buckley–James method for analyzing censored data, with an application to a cardiovascular disease and an HIV/AIDS study

Yu, Li; Orazem, Peter F.; Jolly, Robert W..

Rural firms have a higher survival rate than urban firms. Over the first 13 years after firm entry, the hazard rate for firm exits is persistently higher for urban firms. While differences in firm attributes explain some of the rural-urban gap in firm survival, rural firms retain a survival advantage 18.5% greater than observationally equivalent urban firms. We argue that in competitive markets, the remaining survival advantage for rural firms must be attributable to unobserved factors that must be known at the time of entry. A plausible candidate for such a factor is thinner markets for the capital of failed rural firms. The implied lower salvage value of rural firms suggests that firms sorting into rural markets must have a higher probability of success...

Tipo: Working or Discussion Paper

Palavras-chave: Rural; Urban; Entry; Exit; Survival; Sorting; Salvage value; Community/Rural/Urban Development; Demand and Price Analysis; Financial Economics; Industrial Organization; Labor and Human Capital; Marketing; Production Economics; Productivity Analysis; Risk and Uncertainty; O18; L21; D92.

Ano: 2009

URL: http://purl.umn.edu/54081

Aedes aegypti survival in the presence of Toxorhynchites violaceus (Diptera: Culicidae) fourth instar larvae

Cui, James.

The Buckley–James method and the Cox proportional hazards model were proposed in the 1970s. Both methods can be used to analyze survival-type data, although the former focuses on calculation of the expected value of the survival time and the latter on the relative risk of explanatory variables on the failure event. In cardiovascular disease epidemiological studies, it is essential to correct the effect of taking antihypertensive medicine, which means we need to calculate the expected blood pressure for people who take the medicine. I developed a Stata program to calculate the Buckley–James estimate. I will describe how to use this program to calculate the expected value of a censored outcome and illustrate the method through an example from a...

Tipo: Journal Article

Palavras-chave: Buckley–James method; Censoring; Expectation; Survival; Research Methods/ Statistical Methods.

Ano: 2005

URL: http://purl.umn.edu/117542

Shelter building behavior of Pyrrhopyge papius (Lepidoptera: Hesperiidae) and the use of the Mayfield method for estimating survivorship of shelter-building Lepidopteran larvae

Albeny,Daniel S; Martins,Gustavo F; Andrade,Mateus R; Krüger,Rodrigo F; Vilela,Evaldo F.

The mosquito Aedes aegypti (Linnaeus, 1762) is the main vector of dengue and yellow fever viruses. Different methods have been used to control A. aegypti, including chemical and biological tools. However, chemical control can lead to a subsequent increase in the mosquitoes' insecticide resistance, and biological control represents an important method as an alternative to insecticide usage. Larvae from the Toxorhynchites genus (Diptera: Culicidae) are predators of other mosquitoes and represent a potential natural biocontrol agent of A. aegypti larvae. In the present work, A. aegypti larval survival was studied in the presence of the neotropical Toxorhynchites violaceus (Wiedemann, 1821) fourth instar larvae. Toxorhynchites violaceus consumption of A....

Tipo: Info:eu-repo/semantics/other

Palavras-chave: Predation; Survival.

Ano: 2011

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1984-46702011000400017

Greeney,Harold F.; Walla,Thomas R.; Jahner,Josh; Berger,Ryan.

Estimating the survivorship of lepidopteran larvae in the field poses many problems, most notably the potential for monitored subjects to simply wander away. Larvae of the family Hesperiidae, however, construct and dwell in shelters built out of leaf tissue on their host plants, return to their shelters between feeding bouts, and build a predictable series of shelters during larval ontogeny. Here we describe the shelter building behavior of Pyrrhopyge papius Hopffer, 1874 from northeastern Ecuador. Subsequently we test the use of the Mayfield method, a widely-used ornithological method for estimating survivorship of nests, to examine its utility for monitoring survival in free-living hesperiid larvae. Pyrrhopyge papius builds three distinct shelter types...

Effect of humic acid on survival, ionoregulation and hematology of the silver catfish, Rhamdia quelen (Siluriformes: Heptapteridae), exposed to different pHs

Palavras-chave: Caterpillar; Ecuador; Predation; Skipper; Survival.

Ano: 2010

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1984-46702010000600005

Costa,Silvio T. da; Gressler,Luciane T.; Sutili,Fernando J.; Loebens,Luíza; Lazzari,Rafael; Baldisserotto,Bernardo.

This study evaluates whether humic acid (HA; Aldrich) protects the silver catfish, Rhamdia quelen (Quoy & Gaimard, 1824), against exposure to acidic pH. Survival, levels of Na+, Cl- and K+ plasma, hematocrit, hemoglobin and erythrocyte morphometry were measured. Fish were exposed to 0, 10, 25 and 50 mg L 1 HA at four pH levels: 3.8, 4.0, 4.2 and 7.0 up to 96 hours. None of the fish exposed to pH 3.8 survived for 96 hours into the experiment, and survival of fish subjected to pH 4.0 decreased when HA concentration increased. Plasma Na+ levels decreased when pH was acidic, with no influence of HA, while Cl- levels declined at low pH with increased HA concentration. The levels of K+ at pH 4.0 and 4.2 increased without HA. Hematocrit and hemoglobin...

Thermal tolerance of the zoea I stage of four Neotropical crab species (Crustacea: Decapoda)

Palavras-chave: Blood parameters; Humic acid; Plasma ion levels; Survival.

Ano: 2015

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1984-46702015000300215

Rebolledo,Adriana P.; Collin,Rachel.

ABSTRACT Although larval stages are often considered particularly vulnerable to stressors, for many marine invertebrates studies of thermal tolerance have focused on adults. Here we determined the upper thermal limit (LT50) of the zoea I of four Caribbean crab species (Macrocoeloma trispinosum, Aratus pisonii, Armases ricordi, and Minuca rapax) and compared their thermal tolerance over time and among species. The zoea from the subtidal species M. trispinosum and tree climbing mangrove species A. pisonii had a lower thermal tolerance, 35 and 38.5 °C respectively, than did the semiterrestrial A. ricordi and M. rapax. In all four species tested, the estimates of thermal tolerance depend on the duration of exposure to elevated temperatures. Longer exposures to...

Tipo: Info:eu-repo/semantics/other

Palavras-chave: Caribbean; Larvae; Survival; Temperature; Exposure time.

Ano: 2018

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1984-46702018000100501

Compensatory growth of Malaysian prawns reared at high densities during the nursery phase

R. Bras. Zootec.

Marques,H.L.A.; Lombardi,J.V..

The objective of this work was to verify the occurrence of compensatory growth in Malaysian prawn (Macrobrachium rosenbergii) reared in pens, after being stocked in cages under high densities during nursery phase. The experiment was carried out in 0.5 m² cages and 2-m² pens set in natural bottom pond with 2,400 m². Prawn post-larvae (PL) with an average weight of 0.026 ± 0.012 g (nursery phase) were initially stocked in 16 cages at the densities of 50, 400, 800 and 1,200 PL m-2. Sixty days later, prawns were transferred to 16 growing pens, at the density of 12 prawns m-2. Initial average weight of the prawn in this phase was the final average weight registered in the nursery phase, as follows: 50 PL m-2 = 2.3 ± 0.3 g; 400 PL m-2 = 0.5 ± 0.03 g; 800 PL m-2...

Temperament and reproductive biology: emotional reactivity and reproduction in sheep

Palavras-chave: Biomass; Freshwater prawn; Growing; Macrobrachium rosenbergii; Pens; Survival.

Ano: 2011

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-35982011000400001

R. Bras. Zootec.

Blache,Dominique; Bickell,Samantha L..

Reproductive capacity is controlled by a large number of factors such as season, social interactions and metabolic status. However, the influence of emotional reactivity on reproductive success has not been intensively investigated in farm animals. In this review, we define emotion reactivity and the expression of its inter individual variability named temperament. We briefly describe our protocol to measure temperament in sheep and discuss the heritability of temperament traits. Using the results obtained from our flock of sheep selected for calm or nervous temperament, we illustrate how this selection affects the reproductive biology from changing the inexperienced ewe's response to the male effect to improving lamb survival and ovulation rate. We...