RESUMEN
Broodstock selection programs are currently underway for Atlantic cod (Gadus morhua). To complement and further these selection programs we need to develop sperm cryopreservation procedures. This will allow genomic DNA from males from selected individuals or stocks to be frozen and conserved in perpetuity. In our study we used a full factorial ANOVA design to examine the effects of diluent (Mounib's sucrose-based diluent, Hanks' Balanced Salt Solution, Mounib's sucrose-based diluent+hen's egg yolk, and Hanks' Balanced Salt Solution+hen's egg yolk), cryoprotectant (propylene glycol, dimethyl sulphoxide, and glycerol), and freezing rate (-2.5, -5.0, -7.5, and -10.0°C/min) on motility of cod frozen-thawed sperm. Sperm velocity and morphometric analyses of sperm heads and flagella were also assessed. We found that sperm motility-recovery index was strongly influenced by the presence of higher-order interactions of the factors we tested. The best cryoprotection used diluents that contained hen's egg yolk. Generally, extenders containing propylene glycol yielded higher post-thaw sperm motilities than those with dimethyl sulphoxide or glycerol. In comparison to sperm from other frozen-thawed extenders, sperm from extenders supplemented with propylene glycol had significantly higher curvilinear velocity. Cryopreservation showed no impact on sperm head morphology parameters, however, considerable damage to frozen-thawed sperm flagella was observed. We believe that our experimental/statistical approach and our results add significantly new information to the study of semen biology/cryobiology in fishes. Our findings are also highly relevant to the development of cod mariculture and for aiding in conservation efforts of this very important marine species.
Asunto(s)
Criopreservación/veterinaria , Crioprotectores/farmacología , Gadus morhua , Preservación de Semen/veterinaria , Espermatozoides , Animales , Cruzamiento , Supervivencia Celular , Criopreservación/métodos , ADN , Dimetilsulfóxido/farmacología , Yema de Huevo , Peces , Flagelos/efectos de los fármacos , Flagelos/metabolismo , Congelación , Genoma , Glicerol/farmacología , Masculino , Propilenglicol/farmacología , Semen/efectos de los fármacos , Preservación de Semen/métodos , Bancos de Esperma , Motilidad Espermática/efectos de los fármacos , Espermatozoides/efectos de los fármacos , Espermatozoides/fisiologíaRESUMEN
The North American spiny-cheek crayfish, Orconectes limosus (Cambaridae), endangered in its native range, is a widespread invasive species in European waters and conservationally important carrier of crayfish plague. However, its population structure is poorly known, and no informative genetic markers for the species are available. We tested cross-species transfer of microsatellite loci to spiny-cheek crayfish from 5 other crayfish species. Variability of 10 successfully amplifying loci derived from 4 species was then tested in 60 individuals of O. limosus originating from 3 natural populations: the river Danube at Bogyiszló in Hungary, a pond in Starý Klíèov, and the brook Eernovický, both in the Czech Republic. The allele number within the populations ranged from 4 to 10 alleles per locus, while heterozygosity levels varied from 0.650 to 0.900 for H(o) and from 0.660 to 0.890 for H(e). No linkage disequilibrium and no null alleles were detected. The selected markers are useful for assessing population structure, intraspecific variation, and paternity studies in spiny-cheek crayfish.
Asunto(s)
Astacoidea/crecimiento & desarrollo , Astacoidea/genética , Cruzamiento , Variación Genética , Genética de Población , Repeticiones de Microsatélite/genética , Animales , Marcadores GenéticosRESUMEN
Inositol 1,4,5-trisphosphate receptors (IP(3)Rs) mediate cytosolic free calcium concentration ([Ca(2+)](c)) signals in response to a variety of agonists that stimulate mesangial cell contraction and proliferation. In the present study, we demonstrate that mesangial cells express both type I and III IP(3)Rs and that these receptors occupy different cellular locations. Chronic treatment with transforming growth factor-beta1 (TGF-beta1; 10 ng/ml, 24 h) leads to downregulation of both type I and III IP(3)Rs as measured by immunoblot and confocal analysis. TGF-beta1 treatment does not affect IP(3) levels, and downregulation of type I IP(3)R is not due to enhanced degradation of the protein, as the half-life of type I IP(3)R is unchanged in the presence or absence of TGF-beta1. Functional effects of TGF-beta1-induced downregulation of the IP(3)Rs were evaluated by measuring [Ca(2+)](c) changes in response to epidermal growth factor (EGF) in intact cells and sensitivity of [Ca(2+)](c) release to IP(3) in permeabilized cells. TGF-beta1 pretreatment led to a significant decrease of [Ca(2+)](c) release induced by EGF in intact cells and by submaximal IP(3) (400 nm) in permeabilized cells. Total IP(3)-sensitive [Ca(2+)](c) stores were not changed, as assessed by stimulation with maximal doses of IP(3) (10.5 microm) and thapsigargin-mediated calcium release in permeabilized cells. We conclude that prolonged exposure to TGF-beta1 leads to downregulation of both type I and III IP(3)Rs in mesangial cells and this is associated with impaired sensitivity to IP(3).
Asunto(s)
Canales de Calcio/efectos de los fármacos , Canales de Calcio/metabolismo , Señalización del Calcio/efectos de los fármacos , Mesangio Glomerular/efectos de los fármacos , Mesangio Glomerular/metabolismo , Receptores Citoplasmáticos y Nucleares/efectos de los fármacos , Receptores Citoplasmáticos y Nucleares/metabolismo , Factor de Crecimiento Transformador beta/farmacología , Animales , Canales de Calcio/clasificación , Línea Celular , Factor de Crecimiento Epidérmico/farmacología , Semivida , Inositol 1,4,5-Trifosfato/metabolismo , Inositol 1,4,5-Trifosfato/farmacología , Receptores de Inositol 1,4,5-Trifosfato , Ratones , Modelos Biológicos , Isoformas de Proteínas/metabolismo , Receptores Citoplasmáticos y Nucleares/clasificaciónRESUMEN
Using data obtained from personal interviews with 647 Southeast Asian refugees in Canada, this study tests hypotheses regarding both the association between perceived racial discrimination and depression, and the roles of coping and ethnic identity in conditioning the nature of the discrimination-depression relation. Refugees who reported that they had experienced racial discrimination had higher depression levels than their counterparts who reported no such experiences. Responding to discrimination through confrontation was not significantly associated with depression. Study findings support the effectiveness of forbearance in diminishing the strength of the association between discrimination and depression. The moderating effect of forbearance was conditioned by the level of ethnic identity: The beneficial effect of forbearance was significantly greater among those holding stronger ethnic identification. Cultural and situational interpretations of the findings are presented.
Asunto(s)
Adaptación Psicológica , Trastorno Depresivo/etnología , Prejuicio , Adulto , Asia Sudoriental/etnología , Canadá , Etnicidad , Femenino , Humanos , Masculino , Factores de RiesgoRESUMEN
OBJECTIVES: Occupational therapists sometimes observe an alarming discrepancy between the occupational performance skills developed in the clinical setting and the degree to which the client willingly puts these skills to use outside the clinical environment. The literature strongly suggests that perceived self-efficacy partially explains this discrepancy; however, an understanding of perceived self-efficacy has not yet been integrated into the practice of occupational therapy. Both a lack of awareness of the construct and a lack of ability to assess perceived self-efficacy within the occupational performance domain are responsible for this lack of integration into practice. This article presents the development, reliability, and validity testing of a measure of perceived self-efficacy developed particularly for use by occupational therapists, the Self-Efficacy Gauge. METHOD: Reliability and validity testing was performed through use of a mailed survey (n = 126). Test-retest reliability, internal consistency, and alternate form reliability were examined. In addition, the subjects' scores on the Gauge were compared to actual performance and a hopelessness scale. RESULTS: The Self-Efficacy Gauge has a reasonable degree of reliability when used on a clinical sample whose perceived self-efficacy for occupational performance activities is unlikely to change. The results also provide preliminary support for the validity of the instrument. CONCLUSION: It is recognized that without a gold standard for comparison, validity testing will be an ongoing need.
Asunto(s)
Actividades Cotidianas , Personas con Discapacidad/rehabilitación , Terapia Ocupacional/normas , Autoimagen , Adulto , Anciano , Anciano de 80 o más Años , Personas con Discapacidad/psicología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Reproducibilidad de los Resultados , Autoevaluación (Psicología) , Encuestas y CuestionariosRESUMEN
This study reports the prevalence and risk factors of depression in a large representative community sample of adult Korean immigrants in Toronto, Canada. The Center for Epidemiologic Studies-Depression scale was used to measure depression by applying DSM-III criteria. Results in general suggest few differences between the immigrant community and the larger communities in Canada and the United States. Depressive syndrome was present in 4.5% of the sample, a prevalence similar to rates reported by the Epidemiologic Catchment Area studies. The risk factors associated with depression in larger populations were also found to be related to depression in this sample. Gender, marital status, intention to re-migrate, and social support were the most powerful correlates of depressive syndrome. In summary, Korean immigrants in Toronto are not exceptionally vulnerable to depression, and the social support from informal ethnic networks at the time of arrival has long-lasting effects on their mental health. Future research should focus on how the informal social supports available at the time of arrival are maintained by immigrants and the precise ways in which they exert long-term protective effects.
Asunto(s)
Trastorno Depresivo/epidemiología , Emigración e Inmigración , Etnicidad , Adulto , Canadá/epidemiología , Áreas de Influencia de Salud , Intervalos de Confianza , Etnicidad/estadística & datos numéricos , Femenino , Humanos , Corea (Geográfico)/etnología , Masculino , Matrimonio , Análisis Multivariante , Prevalencia , Factores Sexuales , Apoyo Social , Estados Unidos/epidemiologíaRESUMEN
The Center for Epidemiologic Studies-Depression scale was used to measure depression by applying DSM-III criteria to a community sample of 860 adult Korean immigrants residing in Toronto, Canada. A total of 2.6% of men (95% confidence interval, 1.1% to 4.1%) and 6.7% of women (95% confidence interval, 4.3% to 9.1%) manifested depressive syndrome, rates not substantially different from those reported in North American community populations. The study also identified the subgroups in which the gender differences in depression were the greatest. Both the role demand (or double burden) and power explanations of gender differences might be supported. The mental health implications of social roles, including gender role, may be better understood from cross-cultural or multicultural perspectives.