scholarly journals Effects of dissolved oxygen concentrations on growth, survival and gonadal development of freshwater pearl mussel Lamellidens marginalis

2021 ◽  
Vol 33 (1) ◽  
pp. 99-108
Author(s):  
MD. FIDA HASSAN KAFI ◽  
MD. HASIBUL ISLAM ◽  
MD. HELAL UDDIN ◽  
KIZAR AHMED SUMON ◽  
HARUNUR RASHID
Keyword(s):  
Survival Rate ◽  
Dissolved Oxygen ◽  
Survival Rates ◽  
Pond Water ◽  
Reproductive Organs ◽  
Gonadal Development ◽  
Pearl Mussel ◽  
Freshwater Pearl Mussel ◽  
Relative Growth Rates ◽  
Oxygen Concentrations

The present study was conducted to evaluate the effects of dissolved oxygen concentrations on growth, survival and gonadal development of freshwater pearl mussel (Lamellidens marginalis). Twenty adult L. marginalis were exposed to each of the five different concentrations of dissolved oxygen (DO) i.e (T0, no aeration), and T1, T2, T3 and T4 with one, two, three and four air stone aerators, respectively in fifteen glass aquaria each containing 10L of pond water. DO concentrations were significantly higher in all the treatments compared to the control but there were no significant differences among the treatments. There were significant differences in the growth and survival rates between control and treatments. The relative growth rates (%) were significantly higher in the highest oxygen concentration (T4) compared to other treatments. The survival rate was zero in control (T0), whereas it was 66.67%, 70.00%, 71.67% and 73.33%, respectively for T1, T2, T3 and T4. On day-30, oocytes in T0 were found to be smaller in size, with developing acini and no previtellogenic oocytes; whereas in T1, T2, T3 and T4, previtellogenic oocytes and larger acini were evident. On day-60, vitellogenic oocytes along with few under-developed oocytes started to detach from the acini walls, as well as some already started migration to germinal duct on day-90. This indicates that ovaries of all the treatments were ripe and were ready to spawn between day-60 and -90. On day-30, secondary spermatocytes were observed in testicular acini in case of T0, whereas more developed and dense spermatids were evident in T1, T2, T3 and T4. These results indicate that testes were in late development stages in T0, whereas they were ripe in all the treatments. The current findings indicate that hypoxia slows down growth, reduces survival rate and retards development of reproductive organs in L. marginalis.

A New Life for the St. Croix River

1988 ◽  
Vol 23 (4) ◽  
pp. 568-577
Author(s):  
Harold S. Bailey
Keyword(s):  
Water Quality ◽  
Dissolved Oxygen ◽  
Discharge Rate ◽  
Paper Mill ◽  
Regulated River ◽  
Secondary Treatment ◽  
Pulp And Paper Mill ◽  
Oxygen Regime ◽  
Oxygen Concentrations

Abstract The water quality of the upper 110 kilometres of the St. Croix River is considered to be pristine. A major industrial discharge renders the lower 14 kilometres of the river a water quality limited segment. Prior to 1970 the Georgia-Pacific Pulp and Paper Mill at Woodland, Maine, discharged untreated effluent directly into the river causing dissolved oxygen concentrations to drop well below 5 mg/L, the objective chosen in the interest of restoring endemic fish populations. Since 1972, the Mill has installed primary and secondary treatment, regulated river discharge rate and effluent composition which has greatly improved the summer dissolved oxygen regime. By 1980, dissolved oxygen concentrations were generally above 5.0 mg/L and restocking the river with Atlantic Salmon (Salmo salar) was initiated.

THE PRINTING OF PACIOLI'S SUMMA IN 1494: HOW MANY COPIES WERE PRINTED?

2007 ◽  
Vol 34 (1) ◽  
pp. 125-145 ◽  
Author(s):  
Alan Sangster
Keyword(s):  
Survival Rate ◽  
Survival Rates ◽  
Printing Process

This paper considers the printing of Pacioli's Summa de Arithmetica, Geometria, Proportioni et Proportionalita (Summa) in 1494. In particular, it attempts to answer the question, how many copies of Summa were printed in 1494? It does so through consideration of the printing process, the printer of Summa, the size of the book, survival rates of other “serious” books of the period, and the dates it contains revealing when parts of it were completed. It finds that more copies were published than was previously suggested, and that the survival rate of copies has probably as much to do with the manner in which it was treated once acquired as in the number of copies printed.

scholarly journals Survival after surgery among patients with cholangiocarcinoma in Northeast Thailand according to anatomical and morphological classification

BMC Cancer ◽  
2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Chaiwat Tawarungruang ◽  
Narong Khuntikeo ◽  
Nittaya Chamadol ◽  
Vallop Laopaiboon ◽  
Jaruwan Thuanman ◽  
...  
Keyword(s):  
Survival Rate ◽  
Survival Time ◽  
Median Survival ◽  
Median Survival Time ◽  
Cox Regression ◽  
Survival Rates ◽  
Care Program ◽  
Tumor Location ◽  
Northeast Thailand ◽  
Curative Surgery

Abstract Background Cholangiocarcinoma (CCA) has been categorized based on tumor location as intrahepatic (ICCA), perihilar (PCCA) or distal (DCCA), and based on the morphology of the tumor of the bile duct as mass forming (MF), periductal infiltrating (PI) or intraductal (ID). To date, there is limited evidence available regarding the survival of CCA among these different anatomical and morphological classifications. This study aimed to evaluate the survival rate and median survival time after curative surgery among CCA patients according to their anatomical and morphological classifications, and to determine the association between these classifications and survival. Methods This study included CCA patients who underwent curative surgery from the Cholangiocarcinoma Screening and Care Program (CASCAP), Northeast Thailand. The anatomical and morphological classifications were based on pathological findings after surgery. Survival rates of CCA and median survival time since the date of CCA surgery and 95% confidence intervals (CI) were calculated. Multiple cox regression was performed to evaluate factors associated with survival which were quantified by hazard ratios (HR) and their 95% CIs. Results Of the 746 CCA patients, 514 had died at the completion of the study which constituted 15,643.6 person-months of data recordings. The incidence rate was 3.3 per 100 patients per month (95% CI: 3.0–3.6), with median survival time of 17.8 months (95% CI: 15.4–20.2), and 5-year survival rate of 24.6% (95% CI: 20.7–28.6). The longest median survival time was 21.8 months (95% CI: 16.3–27.3) while the highest 5-year survival rate of 34.8% (95% CI: 23.8–46.0) occurred in the DCCA group. A combination of anatomical and morphological classifications, PCCA+ID, was associated with the longest median survival time of 40.5 months (95% CI: 17.9–63.0) and the highest 5-year survival rate of 42.6% (95% CI: 25.4–58.9). The ICCA+MF combination was associated with survival (adjusted HR: 1.45; 95% CI: 1.01–2.09; P = 0.013) compared to ICCA+ID patients. Conclusions Among patients receiving surgical treatment, those with PCCA+ID had the highest 5-year survival rate, which was higher than in groups classified by only anatomical characteristics. Additionally, the patients with ICCA+MF tended to have unfavorable surgical outcomes. Showed the highest survival association. Therefore, further investigations into CCA imaging should focus on patients with a combination of anatomical and morphological classifications.

scholarly journals The survival rates and risk factors of implants in the early stage: a retrospective study

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Yong Yang ◽  
Huiting Hu ◽  
Mianyan Zeng ◽  
Hongxing Chu ◽  
Zekun Gan ◽  
...  
Keyword(s):  
Risk Factors ◽  
Survival Rate ◽  
Dental Implants ◽  
Bone Quality ◽  
Early Stage ◽  
Survival Rates ◽  
Bone Augmentation ◽  
Early Survival ◽  
Immediate Implantation ◽  
Implant Length

Abstract Background Few large-sample studies in China have focused on the early survival of dental implants. The present study aimed to report the early survival rates of implants and determine the related influencing factors. Methods All patients receiving dental implants at our institution between 2006 and 2017 were included. The endpoint of the study was early survival rates of implants, according to gender, age, maxilla/mandible, dental position, bone augmentation, bone augmentation category, immediate implant, submerged implant category, implant diameter, implant length, implant torque, and other related factors. Initially, SPSS22.0 was used for statistical analysis. The Chi-square test was used to screen all factors, and those with p < 0.05 were further introduced into a multiple logistic regression model to illustrate the risk factors for early survival rates of implants. Results In this study, we included 1078 cases (601 males and 477 females) with 2053 implants. After implantation, 1974 implants were retained, and the early survival rate was 96.15%. Patients aged 30–60 years (OR  2.392), with Class I bone quality (OR  3.689), bone augmentation (OR  1.742), immediate implantation (OR  3.509), and implant length < 10 mm (OR  2.972), were said to possess risk factors conducive to early survival rates. Conclusions The early survival rate of implants in our cohort exceeded 96%, with risk factors including age, tooth position, bone quality, implant length, bone augmentation surgery, and immediate implantation. When the above factors coexist, implant placement should be treated carefully.

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