scholarly journals Brood stock formation of the hermaphrodite finfish species Pagellus erythrinus (common Pandora) from fish reared in captivity

2004 ◽  
Vol 5 (1) ◽  
pp. 187 ◽  
Author(s):  
S.D. KLAOUDATOS ◽  
D.S. KLAOUDATOS
Keyword(s):  
Hormonal Treatment ◽  
Sex Reversal ◽  
Reproductive Period ◽  
Brood Stock ◽  
Pagellus Erythrinus ◽  
Short Period ◽  
Significant Difference ◽  
In Captivity ◽  
Fish Group ◽  
Common Pandora

Formation of brood stock is considered to be one of the most important operations in order to acquire eggs and fry from any promising candidate finfish species for aquaculture production. The sex reversal observed in hermaphrodite species adds to confusion and creates additional complications in forming a brood stock. The present study describes the efforts and the results of the brood stock formation of the hermaphrodite finfish species Pagellus erythrinus (common Pandora) from individuals aged between 4 and 5 years (TL>300mm) reared in floating cages. Six groups were formed (50 fish/group) in all of which females were present comprising 20 to 40% of the population. The presence of females was in contrast to the literature, which reported that sex reversal of the common Pandora is complete in naturally occurring populations with the absence of females in sizes of a total length greater than 220mm, indicating that in captivity sex reversal is not complete for this species. Four of the groups formed spawned under natural environmental conditions without hormonal treatment and the other two groups were administered a different dosage (250 and 500 IU/kg) of Human Chorionic Gonadotropin (HCG) to induce spawning. The reproductive period started in the middle of May and ended at the beginning of July and spontaneous spawning occurred in all groups. Egg release lasted for a mean period of one month for the groups that spawned without hormonal treatment with no significant difference in the number of viable eggs between groups. The groups that spawned under hormonal treatment released eggs for a period of six and seven days, for the group that spawned under the high and low hormonal treatment, respectively, with no significant difference in the number of viable eggs between them. The hormonal induced spawning resulted in egg release within a short period of time ideal for a hatchery. However, the number of viable eggs produced was significantly lower compared to the number of viable eggs produced from groups that spawned without hormonal treatment.

scholarly journals Quality of semen in the reproductive cycle of Cachara (Pseudoplatystoma fasciatum) raised in captivity

2019 ◽  
Vol 41 ◽  
pp. e46517
Author(s):  
Rodrigo Diana Navarro ◽  
Juliana Ventorim Lemos ◽  
Marcela Tosta Ribeiro
Keyword(s):  
Semen Quality ◽  
Sperm Concentration ◽  
Reproductive Period ◽  
Significant Difference ◽  
In Captivity ◽  
Intermediate Part ◽  
Mean Concentration ◽  
Evident Relationship ◽  
Motility Rate

In this study, we evaluated the semen quality of Cachara (Pseudoplatystoma fasciatum) raised in captivity during its reproductive period. For the evaluation of qualitative parameters, we analyzed: sperm morphology, sperm motility, and sperm vigor; while for the quantitative parameter, we analyzed sperm concentration. In general, the main significant difference was found in March, with a motility rate of 40% and a duration of 39 seconds. The highest mean concentration (1.2x10⁸) was observed in February, as well as the highest percentage of defects in the intermediate part of the spermatozoa (59%). The morphological analysis of spermatozoa showed an average of 24.2% abnormalities in the head and 22.7% in the intermediate part of spermatozoa of P. fasciatum for the four months studied. We did not find any evident relationship between the climate changes evaluated and the qualitative and quantitative parameters. The greatest difference between the percentage of normal spermatozoa and the sharp increase of defects in the intermediate piece, observed in February, can be explained by the sudden climate change, with a significant decrease in temperature and relative humidity, and increase in precipitation. These findings demonstrate the importance of maintaining an optimum climate interval during the breeding season for P. fasciatum.

Supercooling Points of Adult Dermacentor variabilis (Acari: Ixodidae) From a Population Near the Northern Distribution Limit

2020 ◽  
Author(s):  
Matthew E M Yunik ◽  
Neil B Chilton
Keyword(s):  
Cold Hardiness ◽  
Dermacentor Variabilis ◽  
Subzero Temperatures ◽  
Host Seeking ◽  
Short Period ◽  
Significant Difference ◽  
Northern Distribution ◽  
Dog Tick ◽  
Provincial Park ◽  
Established Population

Abstract The northern distributional limit of Dermacentor variabilis Say, the American dog tick, is expanding in Saskatchewan and Manitoba (western Canada). The ability of D. variabilis to continue to expand its range northwards will depend upon the ability of individuals within populations at the species distributional edge to withstand very low temperatures during winter. One component of cold hardiness is the supercooling point (SCP), the temperature below 0°C at which an individual freezes. In this study, the SCP was determined for 94 questing D. variabilis adults (44 females and 50 males) from an established population near Blackstrap Provincial Park in Saskatchewan. SCP values ranged from −18.2 to −6.7°C, with a median of −13.3°C. This suggests that host-seeking D. variabilis adults differ in their ability to survive exposure to subzero temperatures, for at least a short period of time, without freezing. The distribution of SCPs was bimodal, but there was no significant difference in SCP values between female and male ticks, and no relationship between SCP and tick body weight. It remains to be determined what factors contribute to the variation in SCP values among questing D. variabilis adults.

Effects of Different Stocking Densities on Growth, Serum Steroid Hormone Concentrations, Gonadosomatic Index and Sex Reversal in the Rice Field Eel, Monopterus albus (Zuiew)

2011 ◽  
Vol 142 ◽  
pp. 233-237
Author(s):  
Han Wen Yuan ◽  
Fang Chen ◽  
Qiao Qing Xu ◽  
Shi Yuan Gong ◽  
Zhang Jie Chu ◽  
...  
Keyword(s):  
Rice Field ◽  
Steroid Hormone ◽  
Gonadosomatic Index ◽  
Stocking Density ◽  
Sex Reversal ◽  
The Other ◽  
Daily Weight Gain ◽  
Monopterus Albus ◽  
Rice Field Eel ◽  
Significant Difference

The effects of stocking density on various growth parameters and sex reversal in the rice field eel (Monopterus albus) were investigated by evaluating steroid hormone, the gonadosomatic index (GSI) and sex ratio. Fish (mean initial weight of 9.88 ± 0.70 g) were stocked to densities of 4, 20, 36, 52, 68, 84 or 100 fish/m2 in cages (2 m × 1 m × 1.5 m) in a pond, with five replicate cages for each density. Fish were fed for 420 days on a formulated isocaloric diet containing 40.22% crude protein and 12.86 MJ/kg. Serum E2 and T concentrations were determined by radioimmunoassays. There were no significant differences in final bodyweight (FBW) and daily weight gain (DWG) for fish in the groups containing less than 52 fish/m2, while FBW and DWG were significant lower in groups at 68 fish/m2 or more. Specific growth rate (SGR) differed significantly between the 84 and 100 fish/m2 groups compared with the 4, 20 and 36 fish/m2 groups. There was no significant difference in SGR in groups containing less than 84 fish/m2. There were no significant difference between the 4 and 20 fish/m2 groups in net yield (NY), but these groups did differ significantly from the other groups. The final condition factors of fish stocked at 84 or 100 fish/m2 were significantly lower than fish stocked at the other densities. E2 and T hormone concentrations declined as stocking density increased, while GSI values increased initially but then reduced with increasing stocking density. Female ratio and survival decreased with increasing stocking density. The proportion of male fish was significantly greater in the three highest stocking density groups. Therefore, high stocking density may promote sex change from female to male in M. albus.

scholarly journals Heterogeneity and effectiveness analysis of COVID-19 prevention and control in major cities in China through time-varying reproduction number estimation

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Qing Cheng ◽  
Zeyi Liu ◽  
Guangquan Cheng ◽  
Jincai Huang
Keyword(s):  
Prevention And Control ◽  
Large Scale ◽  
Reproduction Number ◽  
Correlation Method ◽  
Control Measures ◽  
Time Varying ◽  
Short Period ◽  
Significant Difference ◽  
Prevention And Control Measures ◽  
And Control

AbstractBeginning on December 31, 2019, the large-scale novel coronavirus disease 2019 (COVID-19) emerged in China. Tracking and analysing the heterogeneity and effectiveness of cities’ prevention and control of the COVID-19 epidemic is essential to design and adjust epidemic prevention and control measures. The number of newly confirmed cases in 25 of China’s most-affected cities for the COVID-19 epidemic from January 11 to February 10 was collected. The heterogeneity and effectiveness of these 25 cities’ prevention and control measures for COVID-19 were analysed by using an estimated time-varying reproduction number method and a serial correlation method. The results showed that the effective reproduction number (R) in 25 cities showed a downward trend overall, but there was a significant difference in the R change trends among cities, indicating that there was heterogeneity in the spread and control of COVID-19 in cities. Moreover, the COVID-19 control in 21 of 25 cities was effective, and the risk of infection decreased because their R had dropped below 1 by February 10, 2020. In contrast, the cities of Wuhan, Tianmen, Ezhou and Enshi still had difficulty effectively controlling the COVID-19 epidemic in a short period of time because their R was greater than 1.

Effects of collection zones and storage on hatchability and survival of feral helmeted guineafowl (Numida meleagris galleata pallas) eggs

2021 ◽  
Vol 18 (1) ◽  
pp. 74-81
Author(s):  
A.A. Yusuf ◽  
O.A. Jayeola ◽  
I.O.O. Osunsina ◽  
G.A. Dedeke
Keyword(s):  
National Park ◽  
Captive Breeding ◽  
Storage Systems ◽  
Ecological Zones ◽  
Numida Meleagris ◽  
Significant Difference ◽  
In Captivity ◽  
Protein Supply ◽  
And Storage ◽  
Kainji Lake

The desire to shore up the shortfall in protein supply, the increased awareness of the importance of cholesterol free animal protein, like guineafowl, and the need to conserve their wild genes, have necessitated studies on improved captive breeding of feral helmeted guineafowl. Hence, this study was aimed at determining the effects of ecological zones and storage systems on the guineafowl eggs. Guineafowl eggs (n=214), were collected from identified and monitored-nests within the Kainji Lake National Park (KLNP) and Old Oyo National Park (OONP). Out of 91 eggs collected from KLNP, 32 and 38 were stored at room temperature (RT-21-25°C) and refrigerator (RF-17-20°C), respectively for five days prior to incubation while 21 eggs were not stored (NS-27-29°C), and out of 123 collected from OONP, 70 and 19 were stored for five days prior to incubation at (RT-21-25°C) and (RF-17-20°C), respectively while 34 eggs were (NS- 27-29°C). Prior to incubation, eggs were weighed, the height and width were measured. The process was repeated after incubation for unhatched eggs. Candling was done three days before hatching at day 29 of egg incubation. Embryo status of unhatched eggs was determined by cracking the eggs. Descriptive and inferential statistics were used to analyse the data. The NS eggs from Kainji (7.60%) and Oyo (2.01%) had the lowest percentage shrinkage in weight across the three storage systems. The order was reversed in height with RF eggs from Kainji (0.96%) and Oyo (0.46%) having lowest. The least shrinkage in width of eggs from Oyo was recorded in the RF eggs (0.00%) and in NS (0.59%) from Kainji. Eggs candling showed that presumed fertile (opaque) was highest (69.10%) in NS eggs followed by RT (45.00%). There was no significant difference (p>0.05) between the hatchability of eggs from the two parks though hatchability (7.60%) of Kainji eggs was higher than those of Oyo (7.40%). Further check on fertilization after incubation showed that RT (37.50%) eggs from Kainji were fertilized but were unable to hatch alive so also was RF eggs (21.10%). The study showed that the eggs sizes vary with ecozones while size of the eggs and storage systems affects hatchability and survival of feral helmeted guineafowl eggs in captivity. Keywords: Guineafowl; ecozones; storage systems; incubation; candling; hatchability

scholarly journals Are Hormonal Agents Better Than Chemo İn Metastati̇c Castrati̇on Resistant Prostate Cancer?

2021 ◽  
Author(s):  
Serkan Yıldırım ◽  
Atike Pınar ERDOĞAN ◽  
Cengiz Yılmaz ◽  
Ferhat Ekinci ◽  
Gülcan Bulut ◽  
...  
Keyword(s):  
Overall Survival ◽  
Therapy Group ◽  
Hormonal Treatment ◽  
Progression Free Survival ◽  
Free Survival ◽  
Chemotherapy Group ◽  
Randomized Controlled Studies ◽  
Significant Difference ◽  
Hormonal Therapies ◽  
Multi Center Study

Abstract İNTRODUCTİONIn this study, we aim to determine which treatment is more appropriate in castration-resistant chemotherapy-naive patients. Therefore, docetaxel and agents active in the androgen pathway (abiraterone and enzalutamide) were compared retrospectively in patients progressing on ADT.MATERİAL METHODThe study was designed as a retrospective and multi-center study. Patients from 5 centers in Turkey were included in the study. The primary endpoint of the study was ovreall survival and the secondary endpoint was progression-free survival.RESULTSMedian overall survival of the chemotherapy group was 18.66 months, it was 16.26 months in the hormonal treatment group. There was no statistically significant difference between the groups (p = 0.311). Median progression-free survival of the chemotherapy group was 5.6 months, while it was 9 months in the hormonal therapy group. There was statistically significant difference between the groups (p = 0.024).CONCLUSİONThere was statistical difference in progression-free survival in favor of hormonal therapies in our study. The difference did not reflect on overall survival and there was no difference between hormonal therapies and docetaxel. Heterogeneity in the selection of patients is considered to lead to this result; however, larger randomized controlled studies are needed to determine the most appropriate treatment in these patients.

scholarly journals Therapeutical aspect of trichomoniasis

2003 ◽  
Vol 131 (3-4) ◽  
pp. 156-162 ◽  
Author(s):  
Jelica Vukicevic ◽  
Jasmina Jankicevic
Keyword(s):  
Trichomonas Vaginalis ◽  
Communicable Disease ◽  
Repeated Administration ◽  
Transmitted Infection ◽  
Microbiological Test ◽  
Clinical Forms ◽  
Short Period ◽  
Significant Difference

Trichomoniasis is frequent, parasitic and sexually transmitted infection of genitourinary tract. It is treated by metronidazole (5-nitroimidazole) according to protocol recommended by Center for Disease Control (CDC formerly called: Communicable Disease Center) [19]. The resistance of Trichomonas vaginalis (TV) strains to metronidazole (MND) was described in USA in 1960, and later on in many European countries [8, 9, 10, 11, 12, 13]. In these cases, due to persistent trichomonas infection, it is necessary to repeat MND treatment with moderate modification of dose and/or length of its application. Nevertheless, oncogenic and toxic effects of MND have to be taken into consideration. OBJECT The aim of this study was to investigate and analyze the incidence of TV in STD and lower susceptibility of certain TV strains to MND were analyzed. MATERIAL AND METHODS In three-year period (1999-2001) 612 patients (244 females and 368 males) suspected of STD were examined clinically and microbiologically at the Institute of Dermatovenereology in Belgrade. The patients detected for TV were treated according to CDC protocol. The affected were considered cured if there was no manifest clinical infection, and no TV verified by microbiological test. Results TV was isolated in 216 patients (35.29 % of all subjects). Trichomonas infection was found in 90 (36.88 %) out of 244 tested females and in 126 (32.34 %) of 368 males. Clinically manifested infection, with extensive urethral and vaginal secretion, was recorded in 161 patients, while the asymptomatic form was found in 55 subjects. This result indicates the predominance of manifested trichomonas infections (75.54 % of cases). The difference of distribution of clinical forms of trichomoniasis, in relation to sex, was not statistically significant (c2=0.854; p>0.05). The patients with verified trichomonas infection were treated by metronidazole according to CDC protocol. The recommended therapeutical scheme consisted of three phases proceeding in succession, in so far TV had not been eliminated by previous one. The number of cured patients, according to therapeutical phases, was shown in Table 4. Three patients (1.39 %, 2 males and 1 female) were not cured in spite of all three completed phases of therapeutical protocol. In all three cases, TV was eliminated by MND application in dose of 3 g/daily, during two days. The failure of minute MND treatment was analyzed in relation to clinical forms of the infection (manifested or asymptomatic), as well as in relation to types of infection (single- or associated infection). The incidence of refractory trichomoniasis treated by a single metronidazole dose of 2 g was significantly higher in the group of patients with polyinfection (c2=18.270 p<0.01). There was no significant difference of resistance to a single MND dose between the groups with manifested and asymptomatic trichomoniasis (c2=0.321; p<0.01). The prevalence of TV in vaginal and urethral smears indicates the significant incidence of trichomoniasis in STD. TV was more frequently isolated in patients with clinically manifested infection. TV susceptibility to MND was tested in vitro in aerobic and anaerobic conditions. The resistance of strains under in vitro conditions did not correlate with refractory feature of trichomoniasis to MND application [7 17, 18]. The success of trichomoniasis treatment depends upon multiple factors, including: a) TV susceptibility to drug, b) intravaginal redox potential, c) drug concentration in situ, d) associated microorganisms that may modify the amount of the drug available in situ [7, 18, 21]. The results of our investigation argue for the latter item, verifying that TV resistance to MND is higher in patients with polyinfection in relation to those with monoinfection (significant difference, c2=18.270; p<0.01). Repeated administration of low metronidazole doses may prolong the therapy of trichomonas infections, while application of high doses (over 3 g/day) may result in undesired complications. Given the well-known fact that repeated sublethal doses induce the resistance, would it be more beneficial to begin with slightly higher metronidazole dose (3 g/day) during short period of time (3-5 days)? This will be the subject of our further investigation.

scholarly journals Effect of whitening dentifrices on the surface roughness of a nanohybrid composite resin

2016 ◽  
Vol 10 (02) ◽  
pp. 170-175 ◽  
Author(s):  
Gabriela Migliorin da Rosa ◽  
Luciana Mendonça da Silva ◽  
Márcio de Menezes ◽  
Hugo Felipe do Vale ◽  
Diego Ferreira Regalado ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Composite Resin ◽  
Wilcoxon Test ◽  
Control Group ◽  
Mean Values ◽  
Short Period ◽  
Significant Difference ◽  
Before And After ◽  
Nanohybrid Composite ◽  
One Way Anova

ABSTRACT Objectives: The present study verified the influence of whitening dentifrices on the surface roughness of a nanohybrid composite resin. Materials and Methods: Thirty-two specimens were prepared with Filtek™ Z350 XT (3M/ESPE) and randomly divided into four groups (n = 08) that were subjected to brushing simulation equivalent to the period of 1 month. The groups assessed were a control group with distilled water (G1), Colgate Total 12 Professional Clean (G2), Sensodyne Extra Whitener Extra Fresh (G3), and Colgate Luminous White (G4). A sequence of 90 cycles was performed for all the samples. The initial roughness of each group was analyzed by the Surface Roughness Tester (TR 200-TIME Group Inc., CA, USA). After the brushing period, the final roughness was measured, and the results were statistically analyzed using nonparametric Kruskal–Wallis and Dunn tests for intergroup roughness comparison in the time factor. For intragroup and “Δ Final − Initial” comparisons, the Wilcoxon test and (one-way) ANOVA were, respectively, performed (α = 0.05). Results: The roughness mean values before and after brushing showed no statistically significant difference when the different dentifrices were used. None of the dentifrices analyzed increased significantly the nanohybrid composite resin surface roughness in a 1 month of tooth brushing simulation. Conclusions: These results suggest that no hazardous effect on the roughness of nanohybrid composite resin can be expected when whitening dentifrices are used for a short period. Similar studies should be conducted to analyze other esthetic composite materials.

73 Artificial incubation of resplendent quetzal (Pharomachrus mocinno mocinno) eggs

2019 ◽  
Vol 31 (1) ◽  
pp. 162
Author(s):  
J. R. Martínez Guzmán ◽  
M. Palma-Irizarry ◽  
M. E. Kjelland ◽  
J. A. Quintana López ◽  
S. Romo ◽  
...  
Keyword(s):  
Early Embryo ◽  
Future Research ◽  
Assisted Reproductive Technique ◽  
Artificial Nests ◽  
Exact Test ◽  
Significant Difference ◽  
In Captivity ◽  
Resplendent Quetzal ◽  
Embryonic Death ◽  
Artificial Incubation

The scientific literature lacks information regarding the incubation conditions and hatching success of the resplendent quetzal (Pharomachrus mocinno mocinno). Jesús Estudillo López, founder of the El Nido aviary, was the first to succeed with quetzal reproduction in captivity. Quetzals do not typically reproduce in captivity and the aim of this study was to increase fecundity through artificial incubation. Over a 3-year period (Yr1, Yr2, and Yr3), data about quetzal eggs, artificial incubation, and diet were recorded for 3 quetzal pairs (ranging from ~4-12 years old, with females ~4-8 years old). Eggs were manually collected from artificial nests and egg substitution was utilised. Quetzals can continue laying eggs up to 8 times with egg substitution. Eggs were weighed and placed into an 80W incubator (INCA 200®, DMP Engineering, Tel Aviv, Israel) with an automatic egg turner. The eggs were incubated for 17 to 18 days at 37.2 to 37.6°C with a relative humidity of 20 to 40%. Fisher’s exact test (2-tailed, α=0.05) was used for statistical analyses comparing the numbers of eggs hatched, infertile eggs, and eggs experiencing embryonic death for the study period. Eggs were candled on Day 3 to determine fertility by the presence of a darker area with vasculogenesis. Hatchability (%) was determined by dividing the total number of offspring hatched by the total number of eggs deemed fertile after candling. All of the eggs that did not hatch were opened at the end of the incubation period to detect early embryo death. A total of 27 quetzal eggs [mean weight (g)=17.3, s.d.=1.2] were incubated over 3 years, of which 10 (~37%) hatched, with 3 (30%) fledging and surviving to adulthood. Six of the eggs (~22%) suffered embryonic mortality during incubation, whereas 11 eggs were infertile (~41%). Hatchability over the study period was 62.5% (10/16). During Yr1 and Yr2 two eggs hatched each year, and compared with the 6 eggs that hatched in Yr3, a noteworthy but not significant difference was observed (Yr1v. Yr2, P=1; Yr1v. Yr3, P=0.188; Yr2v. Yr3, P=0.170). Embryonic death of the eggs was also not significantly different between the years (Yr1v. Yr2, P=1; Yr1v. Yr3, P=0.314; Yr2v. Yr3, P=0.303). However, the number of infertile eggs was significantly different between Yr1v. Yr3 (P=0.007) and Yr2v. Yr3 (P=0.003), but not Yr1v. Yr2 (P=1). During Yr1 and Yr2 the diet consisted of fruit (aguacatillo, banana, and papaya) and a mouse pup once a week. In Yr3 the diet was modified to include blueberry and a commercial food for Tucans (Mazuri®; https://www.mazuri.com/) and a new quetzal pair was added. The modified diet will continue to be used given that there were fewer infertile eggs. However, future research will need to be conducted to elucidate which variables specifically contribute to better hatching results. The results of this study demonstrate an assisted reproductive technique for quetzals that can benefit conservation efforts for this species.

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