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Showing 3 results for Ayashi
Volume 3, Issue 3 (Number 3 - 2001)
Abstract
In order to determine the most effective hormones on the in vitro oocyte maturation
(germinal vesicle breakdown - GVBD) in a hybrid sturgeon bester, ovarian follicles were
incubated at the migratory nucleus stage in the presence of several steroids, gonadotropin
preparations and forskolin. Occurrence of GVBD and 17,20β-dihydroxy-4-pregnen-3 -one
(DHP) production were followed during an experimental period of one year of germinal
vesicle (GV) migration. From all the steroids tested, three progesterone derivatives-17α-
hydroxyprogesterone (17αOHP), 17, 20β, 21-trihydroxy-4-pregnen-3-one (17, 20 β, 21-
triol), and DHP-were the most potent steroid inducers of GVBD, followed closely by deoxycorticosterone
(DOC). No GVBD responses were found in ovarian follicles in July
when the GV was still central. The responsiveness increased gradually from then and
reached its peak in November when the GV had migrated fully towards the oocyte periphery.
Their potencys gradually declined later from December and the oocytes lost their
ability to mature the next July when degeneration set in. DHP production by ovarian follicle
during successive months of nucleus migration demonstrated a relatively similar pattern
of GVBD frequencies. These results indicated again a relevant role for DHP on oocyte
maturation in the bester and also suggested that GV localization along with in vitro
oocyte maturation assay can be used as practical tools for selecting the appropriate individuals
in exogenous induced spawning in bester.
Volume 12, Issue 2 (Number 2 - 2010)
Abstract
The biology of Chrysocharis pentheus (Walker) (Hymenoptera: Eulophidae), the most abundant endoparasitoid of Phyllocnistis citrella Stainton (Lepidoptera: Gracillariidae) in Ehime prefecture, Japan, was studied under laboratory and field conditions. The mean immature developmental time and adult longevity at different temperatures (22 to 31°C) under 50-70% RH decreased as the temperature increased, and females survived longer than males. The developmental threshold of male and female was 8.9°C and 11.9°C, respectively. The effective accumulative temperature (thermal constant) for males and females from egg to adult was 181.8 and 238.1 degree-days, respectively. C. pentheus appeared to be a synovigenic species. The offspring sex ratio from females provided with males was 73.8% males and 26.2% females. Presumably, mated females began oviposition 1-2 days after emergence and continued for up to 40 days. Females laid a mean of 118.2±10.10 eggs each, and their longevity reached 32.3±0.30 days at 27±1°C, 50-70% RH. The intrinsic rate of natural increase (rm) was 0.144. Host feeding or stinging without oviposition killed 65.7±8.65 P. citrella larvae per female. Oviposition in the field was highest (62.7%) on the third instar larva of P. citrella, with the rest on the prepupal stage (37.3%), showing a significant preference for third instars. The sex ratio (M:F) of C. pentheus reared from the third instar larvae of host and pupae was 3.3:1.0 and 1.0:3.0 respectively.
Volume 28, Issue 4 (12-2024)
Abstract
This research endeavors to delineate and scrutinize the principal determinants that affect tourist satisfaction with eco-lodges situated in Zanjan Province, as well as to investigate the spatial correlations pertinent to these determinants utilizing online data. In order to fulfill this objective, data were procured from the Jabama platform via automated web mining techniques (n=59), which were subsequently subjected to both statistical and spatial analyses. The findings derived from stepwise multiple regression analysis indicated that the most salient predictors of tourist satisfaction encompassed location (β = 0.372, p < 0.01), price value (β = 0.343, p < 0.01), and information accuracy (β = 0.292, p < 0.01). Furthermore, the spatial autocorrelation analysis conducted through the Local Moran’s I index revealed the existence of statistically significant clusters of tourist satisfaction, particularly in proximity to prominent attractions such as the Soltaniyeh Dome, where levels of satisfaction were notably elevated. The empirical results indicate that these three variables in unison account for 69% of the variability in tourist satisfaction. The implications of this study can guide eco-lodge administrators and tourism policymakers in refining service strategies and pricing frameworks, thereby elevating visitor satisfaction and fostering the sustainable advancement of nature-based tourism in Zanjan Province.
