scholarly journals Effect of Salinities and Dietary Patterns toward Fullness of Gut and Gut Evacuation Time of the Newly Introduced Penaeus merguiensis Larvae

2021 ◽  
Vol 26 (2) ◽  
pp. 71-78
Author(s):  
Mostafa Imhmed Ighwerb ◽  
Johannes Hutabarat ◽  
Ervia Yudiati ◽  
Rudhi Pribadi ◽  
Widianignsih Widianingsih ◽  
...  

The gut capacity of shrimp larvae is minimal, and their digestion is often challenged by the inevitable fact that they tend to develop slowly during the zoea stage. Many studies approved that the digestive capacity of shrimp larvae could be improved by increasing the retention time of food in the intestine. Gut evacuation time and fullness of the gut are crucial parameters in assessing the growth of shrimp larvae, and the diet as well as  environmental conditions indeed influence the activity of these parameters. Although many species of shrimps have a wide salinity tolerance, more specific research on salinity and its relation to the type of diet is necessary to find the optimum condition supporting the growth of shrimp larvae. By employing Penaeus merguiensis larvae, this study evaluates the effect of three nominal salinities (28, 32, and 36 ppt) and types of diets (Diet A: 100% live feed; Diet B: 100% FRIPPAK; Diet C: a combination of Diet A and Diet C, 50 % each) toward the fullness of gut and gut evacuation time of the newly introduced Penaeus merguiensis larvae culture. The result showed that the longest gut evacuation time and the highest percentage of gut's fullness were found in all Zoea reared with Diet A at salinity 28 and 32 ppt; Zoea-1 at 28 ppt with Diet A; Zoea-2 at 32 ppt with Diet A; Zoea-3 at 32 ppt with Diet A. Longer gut evacuation time would have an impact on the higher percentage of the fullness of gut. The higher fullness of the gut also indicates that the larvae have the best capacity to produce energy and achieve optimum growth.

2021 ◽  
Vol 26 (3) ◽  
pp. 197-206
Author(s):  
Mostafa Imhmed Ighwerb ◽  
Johannes Hutabarat ◽  
Ervia Yudiati ◽  
Rudhi Pribadi

The water quality found on the surface is usually better than that accumulated at the seabed and more bottomless sea. When recycled, water usually brings many materials along the path, all the way to reaching its end. Water quality varies from place to place, season, and different types of rock and soil it passes through also influences the possessed quality. By employing Penaeus merguiensis larvae produced by the Marine Research Center Hatchery owned by Jepara's government, this study analyzes varying effects in three nominal salinities (28, 32, and 36 ppt) and types of diets (Diet A: 100% live feed; Diet B: 100% FRIPPAK; Diet C: a combination of Diet A and Diet C, 50 % each) and finds the optimum water quality parameters such as dissolved oxygen, pH, and temperature on the growth of the newly introduced Penaeus merguiensis larvae. The results show that two nominals of water salinities (28 and 32 ppt) with Diet A works well, supporting the growth from most Zoea to Postlarvae-1: Zoea-1 at 28 ppt with Diet A; Zoea-2 at 32 ppt with Diet A; Zoea-3 at 32 ppt with Diet A; Mysis-1 at 28 ppt with Diet A; Mysis-2 at 28 ppt with Diet C; Mysis-3 at 28 ppt with Diet A; Postlarva-1 at 28 ppt with Diet A. All shrimp prefers temperature ranging from 31-32.4 °C with dissolved oxygen of 4.9-5.74 ppm and pH 7.0-8.1. 


2021 ◽  
Vol 882 (1) ◽  
pp. 012007
Author(s):  
I Rodliyah ◽  
R Wijayanti ◽  
A Septiarani ◽  
A Sudrajat ◽  
D Firmansyah

Abstract More than half of the world’s tin production is from secondary ore deposits. However, along with its depletion, PT Timah Tbk has explored and mined the primary deposits in Belitung, one that is expected to become tin’s new source. Tin was found liberated as cassiterite in the secondary deposits, while in the primary, it was associated with other minerals requiring more complex processing. Therefore, a suitable technology is needed to extract the tin from the primary ore deposits. This research aims to observe the extraction of tin from primary deposits (oxide and skarn ores) using HCl wet chlorination, observed at different temperature (60 – 90°C), HCl concentrations (10 – 50 % excess of stoichiometric amount), leaching time (60 – 300 minutes), and with or without the addition of oxidant (hydrogen peroxide, H2O2). The research found that the highest percentage of tin extraction from oxide and skarn ores was 92.32% and 97.28%, respectively. Both results were achieved at the same optimum condition: temperature of 60°C, 50% excess of HCl, 240 minutes of leaching time, and at two-fold excess of the stoichiometric amount of H2O2. It was concluded that oxidative wet chlorination could be used to recover tin from its primary ore deposits.


2018 ◽  
Vol 6 (2) ◽  
pp. 22
Author(s):  
Dimas Ramadhan ◽  
Melya Riniarti ◽  
Trio Santoso

Rising urban development decreased the availability of topsoil for growing media. Therefore, it was necessary to study potential alternative media such as cocopeat. The objective of the study wasto know the optimum composition of cocopeat and soil for optimum growth of Paraserianthes falcataria and Intsia palembanica. The method used was a complete random design. Five treatments were applied to each seedling, included: A (100% soil), B (75% soil + 25% cocopeat), C (50% soil + 50% cocopeat), D (25% soil + 75% cocopeat) and E (100% cocopeat). Seedlings growth were analyzed using analysis of variance, followed by least significant different (LSD) test. Result showed that the 25% cocopeat compound was the most optimum composition for Intsia palembanica seedlings, while 25% and 50% of cocopeat composition was the most optimum for the Paraserianthes falcataria growth. Keyword : cocopeat, growing media, Intsia palembanica, Paraserianthes falcataria, seedling growth.


1970 ◽  
Vol 32 (2) ◽  
pp. 189-195
Author(s):  
Po-Teen Lim ◽  
Chui-Pin Leaw ◽  
Shinnosuke Kaga ◽  
Katsushi Sekiguchi ◽  
Takehiko Ogata

Growth response of five clonal cultures of Alexandrium obtained from tropical and temperate waters were examined. Experiments were carried out in eighteen variable temperature-salinity conditions (temperatures of 15 °C, 20°C, and 25°C; salinities between 5 to 30 psu) under constant illumination of 150 ± 10.0 Amol m-2 s-' at 15:9 light:dark photo-cycle. Our results showed optimum growth of all Alexandrium species at 20 - 25°C. The salinity range for optimum growth however varied among the species. Growth rates of A. eine, A. insuetum, and A. fraterculus (0.28 — 0.37 day') were higher than those of A. leei and A. pseudogoniaulax under the same culture conditions (0.14 —0.22 day-'). The three temperate species showed positive growth at suboptimum temperature, 15°C, but the tropical species did not grow and died off. Salinity tolerance of the five species in decreasing order was A. pseudogoniaulax > A. leei > A. insuetum > A. affine > A. fraterculus. Results of the present study showed vast variations in salinity tolerance among the Alexandrium species regardless the geographical origins. Adaptation of the temperate species at higher temperature indicated that the species might proliferate in warm tropical waters.


2019 ◽  
Vol 1 (1) ◽  
pp. 26-30
Author(s):  
Ridwan Syarif ◽  
◽  
Intan Nurul Rizki ◽  
Ridho Kresna Wattimena ◽  
Siti Khodijah Chaerun ◽  
...  

A modification of bacterial medium using calcium lactate pentahydrate was developed for calcium carbonate precipitation. A total of five strains of bacteria were cultivated on the solution medium containing nutrient broth and calcium lactate pentahydrate. In this study, the variation of 3.2 mM and 16.2 mM of calcium lactate pentahydrate was used to obtain the optimum condition for bacterial growth. The results showed that isolated strains CPB 1, CPB 3, and CPB 5 with medium containing nutrient broth and 3.2 mM calcium lactate pentahydrate gave the optimum growth, pH and Eh, thus being favourable for the process of calcium carbonate precipitation. Hence, this will be useful for self-healing concrete.


Author(s):  
T. Ichinokawa ◽  
H. Maeda

I. IntroductionThermionic electron gun with the Wehnelt grid is popularly used in the electron microscopy and electron beam micro-fabrication. It is well known that this gun could get the ideal brightness caluculated from the Lengumier and Richardson equations under the optimum condition. However, the design and ajustment to the optimum condition is not so easy. The gun has following properties with respect to the Wehnelt bias; (1) The maximum brightness is got only in the optimum bias. (2) In the larger bias than the optimum, the brightness decreases with increasing the bias voltage on account of the space charge effect. (3) In the smaller bias than the optimum, the brightness decreases with bias voltage on account of spreading of the cross over spot due to the aberrations of the electrostatic immersion lens.In the present experiment, a new type electron gun with the electrostatic and electromagnetic lens is designed, and its properties are examined experimentally.


1978 ◽  
Vol 39 (01) ◽  
pp. 193-200 ◽  
Author(s):  
Erwin F Workman ◽  
Roger L Lundblad

SummaryAn improved method for the preparation of bovine α-thrombin is described. The procedure involves the activation of partially purified prothrombin with tissue thromboplastin followed by chromatography on Sulfopropyl-Sephadex C-50. The purified enzyme is homogeneous on polyacrylamide discontinuous gel electrophoresis and has a specific activity toward fibrinogen of 2,200–2,700 N.I.H. U/mg. Its stability on storage in liquid media is dependent on both ionic strenght and temperature. Increasing ionic strength and decreasing temperature result in optimal stability. The denaturation of α-thrombin by guanidine hydrochloride was found to be a partially reversible process with the renatured species possessing properties similar to “aged” thrombin. In addition, the catalytic properties of a-thrombin covalently attached to agarose gel beads were also examined. The activity of the immobilized enzyme toward fibrinogen was affected to a much greater extent than was the hydrolysis of low molecular weight, synthetic substrates.


1981 ◽  
Vol 45 (02) ◽  
pp. 121-126 ◽  
Author(s):  
Utako Okamoto ◽  
Noboru Horie ◽  
Yoko Nagamatsu ◽  
Jun-Ichiro Yamamoto

SummaryMilk plasminogen-activator was partially purified from human transitional milk collected at about 10 days after delivery, by a five-step procedure involving chloroform treatment, ammonium sulfate precipitation, and column chromatography on Sephadex G-150, CM Sephadex C-50 and DEAE Sephadex A-50. This gave milk-activator with a maximum purification factor of about 2,400-fold with respect to the skimmed milk. The CM Sephadex-step preparation showed, on polyacrylamide gel electrophoresis, a single plasminogen-activator activity band located between the bands of albumin and prealbumin of human serum. This preparation exhibited no kinin forming activity. The activator hydrolyzed acetyl-glycyl-L-lysine methyl ester with similar order kinetic constants to urokinase, and was inhibited strongly by diisopropyl-fluorophosphate. The molecular weight of the activator as estimated by gel filtration was approximately 86,000, the isoelectric points as estimated by gel isoelectric focusing were pH 7.2, 6.9 and 6.6, and the activator activity was not quenched by antiurokinase globulin, indicating that the milk-activator is a different entity from urokinase.


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