Cryopreservation of Gametes and Larvae of the Eastern Oyster Crassostrea Virginica.

Storage of gametes and larvae offers benefits for research and commercial oyster production and should be applicable in the hatchery at a commercial scale. We optimized refrigerated storage of eastern oyster sperm. Significant differences were found in the motility of sperm suspended in artificial sea water (ASW) of different osmotic pressures (P \u3c 0.001). The highest motility was found in undiluted sperm and the lowest in 1:31 dilution. The greatest larval survival at 12 h (48%) was obtained with sperm diluted in calcium-free Hanks\u27 balanced salt solution (C-F HBSS). Thus, for storage of longer than 1 d, it is best to leave samples undiluted. However, when sperm samples are diluted, it is best to maintain high sperm concentrations and to use C-F HBSS as an extender. Samples were frozen at -2.5°C/min, held for 5 min at -30°C, and plunged in liquid nitrogen using 10% propylene glycol (PG) as the cryoprotectant for sperm and 10% or 15% PG for trochophore larvae. Motility and fertilizing ability of thawed sperm were affected by cryoprotectant concentration and thawing temperature (P = 0.0001). Larval survival was affected by the concentration of larvae per straw (P = 0.0011). Frozen samples were transported to an oyster hatchery at Grand Isle, Louisiana. After 4 months, 1,000 oysters from the control group, 230 oysters produced from thawed sperm, and 850 oysters from thawed larvae were found. Oysters produced from thawed larvae developed normally in the hatchery, demonstrating opportunities for use of cryopreservation in research and aquaculture. Flow cytometry with the fluorescent dyes Sybr-14 and propidium iodide (PI) was used to assess membrane damage of thawed sperm, and rhodamine 123 and PI were used to assess mitochondrial function. Preliminary studies of cryopreservation of oyster eggs were performed. Fluorescein diacetate (FDA) was used to identify viable eggs. Dimethyl sulfoxide (0.88 M and 1.75 M) and sucrose (0.12 M and 0.25 M) were the least toxic cryoprotectants evaluated. The cooling rate yielding least damage to eggs was -1.5°C per min. However, only an average of 14 eggs (out of 200) were stained with FDA in thawed samples and none were fertilizable

Effects of Cognition, Meta-Cognition and Social Affective Strategies through application of the module "Learning to Learn" in University Students

Efeitos da Cognição, Meta-Cognição e Estratégias Sócio-Afetivas em Estudantes Universitários No campo da psicologia cognitiva, o estudo das estratégias de aprendizagem e ensino despertaram um interesse crescente.  Este trabalho mostra o efeito da aplicação de um módulo chamado "aprender a aprender" aplicado a estratégias de aprendizagem em estudantes do segundo ciclo da Universidade Nacional da Amazônia do Peru. A abordagem quantitativa foi utilizada, o desenho foi quase-experimental e o instrumento um questionário de auto-relato. A amostra foi um grupo de cento e vinte e três estudantes universitários (n=120). O efeito do módulo aprende a aprender não apresenta uma melhoria significativa (p>0,05) nas estratégias de aprendizagem. A maturação e a motivação interna foram fatores que poderiam explicar este achado. Palavras-chave: Estratégias de Aprendizagem, Cognição, Metacognição, Estratégias Socioemocionais.   Effects of Cognition, Meta-Cognition and Social Affective Strategies through application of the module "Learning to Learn" in University Students ABSTRACT. In the field of cognitive psychology, the study of learning and teaching strategies has aroused a growing interest.  This work shows the effect of the application of a module called “learning to learn” applied to learn strategies in students of the second term of the National University of the Amazonia from Peru. The quantitative approach was used, the design was quasi-experimental and the instrument a self-reporting questionnaire. The sample was a group of one hundred twenty-three university students (n=120). The effect of the module learns to learn does not present a significant improvement (p>0.05) in the learning strategies. Maturation and internal motivation were factors that could explain this finding. Keywords: Learning Strategies, Cognitive, Metacognitive, Social Affective Strategies.   Efectos de las estrategias cognitivas, meta cognitivas y socio afectivas en estudiantes universitarios RESUMEN. En el campo de la psicología cognitiva el estudio de las estrategias de enseñanza y aprendizaje ha despertado un creciente interés. Este trabajo muestra el efecto de la aplicación de un módulo llamado: “Aprender a Aprender” aplicado en las estrategias de aprendizaje en los estudiantes del segundo ciclo de la Universidad Nacional del Amazonas en Perú. El método utilizado fue cuantitativo, el diseño cuasi experimental y los instrumentos aplicados fueron cuestionarios. La muestra constituyó de un grupo de ciento veinte estudiantes universitarios (n=120). El efecto del módulo “Aprender a Aprender” no representó una mejora significativa (p > 0.05) en las estrategias de aprendizaje. La maduración y la motivación interna son factores que podrían explicar este hallazgo. Palabras clave: Estrategias de Aprendizaje, Cognición, Meta-cognición, Estrategias socioemocionales.Efeitos da Cognição, Meta-Cognição e Estratégias Sócio-Afetivas em Estudantes Universitários No campo da psicologia cognitiva, o estudo das estratégias de aprendizagem e ensino despertaram um interesse crescente.  Este trabalho mostra o efeito da aplicação de um módulo chamado "aprender a aprender" aplicado a estratégias de aprendizagem em estudantes do segundo ciclo da Universidade Nacional da Amazônia do Peru. A abordagem quantitativa foi utilizada, o desenho foi quase-experimental e o instrumento um questionário de auto-relato. A amostra foi um grupo de cento e vinte e três estudantes universitários (n=120). O efeito do módulo aprende a aprender não apresenta uma melhoria significativa (p>0,05) nas estratégias de aprendizagem. A maturação e a motivação interna foram fatores que poderiam explicar este achado. Palavras-chave: Estratégias de Aprendizagem, Cognição, Metacognição, Estratégias Socioemocionais.   Effects of Cognition, Meta-Cognition and Social Affective Strategies through application of the module "Learning to Learn" in University Students ABSTRACT. In the field of cognitive psychology, the study of learning and teaching strategies has aroused a growing interest.  This work shows the effect of the application of a module called “learning to learn” applied to learn strategies in students of the second term of the National University of the Amazonia from Peru. The quantitative approach was used, the design was quasi-experimental and the instrument a self-reporting questionnaire. The sample was a group of one hundred twenty-three university students (n=120). The effect of the module learns to learn does not present a significant improvement (p>0.05) in the learning strategies. Maturation and internal motivation were factors that could explain this finding. Keywords: Learning Strategies, Cognitive, Metacognitive, Social Affective Strategies.   Efectos de las estrategias cognitivas, meta cognitivas y socio afectivas en estudiantes universitarios RESUMEN. En el campo de la psicología cognitiva el estudio de las estrategias de enseñanza y aprendizaje ha despertado un creciente interés. Este trabajo muestra el efecto de la aplicación de un módulo llamado: “Aprender a Aprender” aplicado en las estrategias de aprendizaje en los estudiantes del segundo ciclo de la Universidad Nacional del Amazonas en Perú. El método utilizado fue cuantitativo, el diseño cuasi experimental y los instrumentos aplicados fueron cuestionarios. La muestra constituyó de un grupo de ciento veinte estudiantes universitarios (n=120). El efecto del módulo “Aprender a Aprender” no representó una mejora significativa (p > 0.05) en las estrategias de aprendizaje. La maduración y la motivación interna son factores que podrían explicar este hallazgo. Palabras clave: Estrategias de Aprendizaje, Cognición, Meta-cognición, Estrategias socioemocionales.Efeitos da Cognição, Meta-Cognição e Estratégias Sócio-Afetivas em Estudantes Universitários No campo da psicologia cognitiva, o estudo das estratégias de aprendizagem e ensino despertaram um interesse crescente.  Este trabalho mostra o efeito da aplicação de um módulo chamado "aprender a aprender" aplicado a estratégias de aprendizagem em estudantes do segundo ciclo da Universidade Nacional da Amazônia do Peru. A abordagem quantitativa foi utilizada, o desenho foi quase-experimental e o instrumento um questionário de auto-relato. A amostra foi um grupo de cento e vinte e três estudantes universitários (n=120). O efeito do módulo aprende a aprender não apresenta uma melhoria significativa (p>0,05) nas estratégias de aprendizagem. A maturação e a motivação interna foram fatores que poderiam explicar este achado. Palavras-chave: Estratégias de Aprendizagem, Cognição, Metacognição, Estratégias Socioemocionais.   Effects of Cognition, Meta-Cognition and Social Affective Strategies through application of the module "Learning to Learn" in University Students ABSTRACT. In the field of cognitive psychology, the study of learning and teaching strategies has aroused a growing interest.  This work shows the effect of the application of a module called “learning to learn” applied to learn strategies in students of the second term of the National University of the Amazonia from Peru. The quantitative approach was used, the design was quasi-experimental and the instrument a self-reporting questionnaire. The sample was a group of one hundred twenty-three university students (n=120). The effect of the module learns to learn does not present a significant improvement (p>0.05) in the learning strategies. Maturation and internal motivation were factors that could explain this finding. Keywords: Learning Strategies, Cognitive, Metacognitive, Social Affective Strategies.   Efectos de las estrategias cognitivas, meta cognitivas y socio afectivas en estudiantes universitarios RESUMEN. En el campo de la psicología cognitiva el estudio de las estrategias de enseñanza y aprendizaje ha despertado un creciente interés. Este trabajo muestra el efecto de la aplicación de un módulo llamado: “Aprender a Aprender” aplicado en las estrategias de aprendizaje en los estudiantes del segundo ciclo de la Universidad Nacional del Amazonas en Perú. El método utilizado fue cuantitativo, el diseño cuasi experimental y los instrumentos aplicados fueron cuestionarios. La muestra constituyó de un grupo de ciento veinte estudiantes universitarios (n=120). El efecto del módulo “Aprender a Aprender” no representó una mejora significativa (p > 0.05) en las estrategias de aprendizaje. La maduración y la motivación interna son factores que podrían explicar este hallazgo. Palabras clave: Estrategias de Aprendizaje, Cognición, Meta-cognición, Estrategias socioemocionales.Efeitos da Cognição, Meta-Cognição e Estratégias Sócio-Afetivas em Estudantes Universitários No campo da psicologia cognitiva, o estudo das estratégias de aprendizagem e ensino despertaram um interesse crescente.  Este trabalho mostra o efeito da aplicação de um módulo chamado "aprender a aprender" aplicado a estratégias de aprendizagem em estudantes do segundo ciclo da Universidade Nacional da Amazônia do Peru. A abordagem quantitativa foi utilizada, o desenho foi quase-experimental e o instrumento um questionário de auto-relato. A amostra foi um grupo de cento e vinte e três estudantes universitários (n=120). O efeito do módulo aprende a aprender não apresenta uma melhoria significativa (p>0,05) nas estratégias de aprendizagem. A maturação e a motivação interna foram fatores que poderiam explicar este achado. Palavras-chave: Estratégias de Aprendizagem, Cognição, Metacognição, Estratégias Socioemocionais.   Effects of Cognition, Meta-Cognition and Social Affective Strategies through application of the module "Learning to Learn" in University Students ABSTRACT. In the field of cognitive psychology, the study of learning and teaching strategies has aroused a growing interest.  This work shows the effect of the application of a module called “learning to learn” applied to learn strategies in students of the second term of the National University of the Amazonia from Peru. The quantitative approach was used, the design was quasi-experimental and the instrument a self-reporting questionnaire. The sample was a group of one hundred twenty-three university students (n=120). The effect of the module learns to learn does not present a significant improvement (p>0.05) in the learning strategies. Maturation and internal motivation were factors that could explain this finding. Keywords: Learning Strategies, Cognitive, Metacognitive, Social Affective Strategies.   Efectos de las estrategias cognitivas, meta cognitivas y socio afectivas en estudiantes universitarios RESUMEN. En el campo de la psicología cognitiva el estudio de las estrategias de enseñanza y aprendizaje ha despertado un creciente interés. Este trabajo muestra el efecto de la aplicación de un módulo llamado: “Aprender a Aprender” aplicado en las estrategias de aprendizaje en los estudiantes del segundo ciclo de la Universidad Nacional del Amazonas en Perú. El método utilizado fue cuantitativo, el diseño cuasi experimental y los instrumentos aplicados fueron cuestionarios. La muestra constituyó de un grupo de ciento veinte estudiantes universitarios (n=120). El efecto del módulo “Aprender a Aprender” no representó una mejora significativa (p > 0.05) en las estrategias de aprendizaje. La maduración y la motivación interna son factores que podrían explicar este hallazgo. Palabras clave: Estrategias de Aprendizaje, Cognición, Meta-cognición, Estrategias socioemocionales.En el campo de la psicología cognitiva, el estudio de las estrategias de enseñanza y aprendizaje ha despertado un interés creciente. Este extenso trabajo sobre la aplicación de un módulo llamado "Aprender a aprender" se aplica a las estrategias de aprendizaje de los estudiantes en el segundo ciclo de la Universidad Nacional de Amazonas en Perú. los instrumentos aplicados fueron cuestionarios. La mayor constitución de un grupo de veinticinco estudiantes universitarios (n = 120). El efecto del módulo "Aprender a aprender" no es una mejora significativa (p> 0.05) en las estrategias de aprendizaje. La maduración y la motivación interna son factores que podrían explicar este sello distintivo

Zebrafish Reproduction: Revisiting In Vitro Fertilization to Increase Sperm Cryopreservation Success

Although conventional cryopreservation is a proven method for long-term, safe storage of genetic material, protocols used by the zebrafish community are not standardized and yield inconsistent results, thereby putting the security of many genotypes in individual laboratories and stock centers at risk. An important challenge for a successful zebrafish sperm cryopreservation program is the large variability in the post-thaw in vitro fertilization success (0 to 80%). But how much of this variability was due to the reproductive traits of the in vitro fertilization process, and not due to the cryopreservation process? These experiments only assessed the in vitro process with fresh sperm, but yielded the basic metrics needed for successful in vitro fertilization using cryopreserved sperm, as well. We analyzed the reproductive traits for zebrafish males with a strict body condition range. It did not correlate with sperm volume, or motility (P>0.05), but it did correlate with sperm concentration. Younger males produced more concentrated sperm (P<0.05). To minimize the wastage of sperm during the in vitro fertilization process, 106 cells/ml was the minimum sperm concentration needed to achieve an in vitro fertilization success of ≥ 70%. During the in vitro process, pooling sperm did not reduce fertilization success (P>0.05), but pooling eggs reduced it by approximately 30 to 50% (P<0.05). This reduction in fertilization success was due not to the pooling of the females' eggs, but to the type of tools used to handle the eggs. Recommendations to enhance the in vitro process for zebrafish include: 1) using males of a body condition closer to 1.5 for maximal sperm concentration; 2) minimizing sperm wastage by using a working sperm concentration of 106 motile cells/ml for in vitro fertilization; and 3) never using metal or sharp-edged tools to handle eggs prior to fertilization

Preserving and Using Germplasm and Dissociated Embryonic Cells for Conserving Caribbean and Pacific Coral

Coral reefs are experiencing unprecedented degradation due to human activities, and protecting specific reef habitats may not stop this decline, because the most serious threats are global (i.e., climate change), not local. However, ex situ preservation practices can provide safeguards for coral reef conservation. Specifically, modern advances in cryobiology and genome banking could secure existing species and genetic diversity until genotypes can be introduced into rehabilitated habitats. We assessed the feasibility of recovering viable sperm and embryonic cells post-thaw from two coral species, Acropora palmata and Fungia scutaria that have diffferent evolutionary histories, ecological niches and reproductive strategies. In vitro fertilization (IVF) of conspecific eggs using fresh (control) spermatozoa revealed high levels of fertilization (>90% in A. palmata; >84% in F. scutaria; P>0.05) that were unaffected by tested sperm concentrations. A solution of 10% dimethyl sulfoxide (DMSO) at cooling rates of 20 to 30°C/min most successfully cryopreserved both A. palmata and F. scutaria spermatozoa and allowed producing developing larvae in vitro. IVF success under these conditions was 65% in A. palmata and 53% in F. scutaria on particular nights; however, on subsequent nights, the same process resulted in little or no IVF success. Thus, the window for optimal freezing of high quality spermatozoa was short (∼5 h for one night each spawning cycle). Additionally, cryopreserved F. scutaria embryonic cells had∼50% post-thaw viability as measured by intact membranes. Thus, despite some differences between species, coral spermatozoa and embryonic cells are viable after low temperature (−196°C) storage, preservation and thawing. Based on these results, we have begun systematically banking coral spermatozoa and embryonic cells on a large-scale as a support approach for preserving existing bio- and genetic diversity found in reef systems

Effect of age and environmental conditions on the movement characteristics of Pacific oyster ( Crassostrea gigas

The movement characteristics of Pacific oyster trochophores have received very little coverage in the scientific literature. Described here are not only changes in the swimming characteristics of Crassostrea gigas trochophores (size: 53-77 mu m) in relation to time after fertilization and to inter-female variation but also the effects of salinity and pH on movement characteristics. The percentage of motile trochophores was measured on images obtained through a dissecting microscope and the Velocity Average Path (VAP) was assessed using a Computer Assisted Sperm Analysis (CASA) system. At 20 degrees C, the first movements of the trochophores were observed at 6.5 h post-fertilization. The mean (+/- SD) percentage of swimming trochophores and the VAP observed in seawater at 11.5 h post-fertilization were 85 +/- 10% and 146 +/- 75 mu m s(-1), respectively (n = 8 females). Significant inter-female variation in the percentage of motile trochophores (range: +/- 16-93 +/- 3%) and in the VAP (55 +/- 47 -180 +/- 90 mu m s(-1)) was detected. Most of the trochophores were motile in a 9 parts per thousand salinity solution. Adjusting the pH of the seawater to values from 5.10 to 9.08 had no effect on swimming characteristics. The present study shows that the movement of oyster trochophores exhibits high plasticity in relation to environmental conditions because the highest percentages of swimming trochophores and optimal velocity values were recorded within large ranges of salinity and pH. Further research is required to determine whether the swimming performances of trochophores can be used to assess embryo quality in commercial hatcheries