scholarly journals Building a set of criteria for selection of natural clam beds (Lutraria rhynchaena, Jonas 1844) as broodstock source for seed production and gene conservation in Cat Ba - Ha Long bay

2019 ◽  
Vol 19 (3) ◽  
pp. 395-404
Author(s):  
Do Manh Hao ◽  
Dao Thi Anh Tuyet ◽  
Nguyen Tien Dat ◽  
Hoang Thi Thanh Nga ◽  
Le Minh Hiep ◽  
...  

Building on a set of criteria used as a scientific basis for conservation zoning of natural marine resources is essential. In this study, we propose the set of criteria to select the suitable natural clam beds of Lutraria rhynchaena for protection priority from 16 sites in Cat Ba - Ha Long bay. Research results have built a set of 13 different criteria, including area, density, benthic substrate, food organisms, turbidity, water flow, water depth, predators, salinity, benthic organisms, pollution, area location and zoning conflicts. The criteria are divided into 5 groups, in which the area and density have the highest coefficent of 5, followed by the zoning conflict with the coefficient of 4, the pollution with the coefficient of 3, the efficient of benthic substrate and  water flow is 2, the remaining criteria have a same coefficient of 1. The highest points are evaluated at Tung Sau bed (station 12) with a score of 254 points, followed by Van Boi beach (station 7) with a score of 235 points, the bed is in Trinh Nu Cave (Station 13) with a score of 229 points, which are proposed to be prioritized sites for conservation.

2020 ◽  
Vol 15 (1) ◽  
pp. 721-734
Author(s):  
Do Manh Hao ◽  
Do Trung Sy ◽  
Dao Thi Anh Tuyet ◽  
Le Minh Hiep ◽  
Nguyen Tien Dat ◽  
...  

AbstractLutraria rhynchaena Jonas, 1844 is of great commercial interest, but its reserves have dramatically declined over recent decades. Therefore, there is an urgent need of scientific basis to propose effective fishery management measures and improve artificial aquaculture of the clam. In this study, we investigated the distribution and density of L. rhynchaena, sediment characteristics, and established the clam’s reproductive cycle through monthly observations from August 2017 to July 2018. The study results showed that distribution and density of clams are related to sediment types, and the sediment type of medium sand is likely the best benthic substrate for the clams. The spawning of clams occurred throughout the year with three spawning peaks in January, April and September. For the sustainable management of the clam resource in Cat Ba-Ha Long Bay, the fishery authorities can issue a ban on harvest of the clam in spawning peak months in January, April and September.


1976 ◽  
Vol 56 (4) ◽  
pp. 805-809 ◽  
Author(s):  
V. M. BENDELOW

A procedure that provides information on the suitability of barley for malting and, brewing purposes is described. Three parameters are measured: mash filtration rate, wort viscosity and wort-reducing sugar content, as maltose. Maltose is determined by an auto-analyzer method and this is a satisfactory alternative to the specific gravity procedure for the estimation of percent extract. The addition of these criteria to those already in use enables more discriminatory selection at early generations of barley-breeding programs. The technique requires only one sample extraction and 18 g of laboratory malt.


Author(s):  
L.L. Zakharova ◽  
◽  
G.A. Zhorov ◽  
V.I. Dorozhkin ◽  
◽  
...  

Negative impact on the environment as a result of economic activity of man increasingly becomes the character of combined pollution of ecotoxicants, including xenobiotics of radiation and chemical nature. In animal husbandry in ecologically unfavorable regions, sorbtion-detoxication technologies based on the complex application of bioprotective substances of different origin are used to reduce the intake and accumulation of xenobiotics, to normalize the physiological state of animals and to obtain safe products. It is necessary to observe certain principles ensuring compatibility of components, a wide range of bioprotective action, efficiency and safety at their use in developing the compositions of such sorption-detoxifying complexes. The article substantiates the criteria that should be followed in creating sorption-detoxifying complexes and presents groups of drugs with different mechanisms of action (sorbents, antioxidants, immunomodulators, adaptogens and other biologically active substances) for inclusion in the formulations of combined compositions.


1982 ◽  
Vol 15 (12) ◽  
pp. 458-463 ◽  
Author(s):  
R. S. Medlock

Flow measurement has a long history extending over a period of about 3000 years, but it was only just over 200 years ago that the subject was first studied on a scientific basis and it was only 20 years ago that a surge of new techniques became available. Today there is a wide selection of methods and equipment to enable flow to be measured whether the medium is in the form of a liquid, gas, vapour or solid, or any combination thereof. According to the application, volumetric flow rate can be measured over a range exceeding 10−5m3/h to 106m3/h which in everday terms is equivalent to a cupful per day to the flow of a very large river. The price of a flowmeter can be as small as a few pounds or in excess of £1 million depending on the accuracy and capacity required. References are made to about 50 types of flow metering devices which can be classified into 11 groups.


Author(s):  
Jung-Hyun Ban ◽  
Tae-Ho Kim

The purpose of this study was to identify changes in the center of pressure during stair ascending in subjects with chronic ankle instability while different angles of foot are applied. The subjects of this study were 20 male and female adults with chronic ankle instability were selected from among the employees of D Hospital in Daegu Metropolitan City. The criteria for selection of subjects with chronic ankle instability were those who felt wobbling in the ankle joint and scored not higher than 24 points in a test using the Cumberland Ankle Instability Tool (CAIT). The subjects carried out stair ascending in neutral, toe-in and toe-out postures, respectively, and changes in the center of pressure (COP) were compared and analyzed. The results of this study, no statistically significant difference appeared in the comparison between the toe-in posture and neutral posture or between the neutral posture and the toe-out posture but medial/lateral movements of the center of pressure showed significant differences between the toe-in and toe-out postures. In addition, the total travel range and the moving range of the center of pressure, the average velocity, and the anterior/posterior movements of the center of pressure showed no statistically significant difference among all three postures. As a result, it could be seen that when adults with chronic ankle instability climb the stairs, the toe-in posture reduce the medial/lateral movements of the center of pressure thereby increasing the stability of the ankle and effectively preventing re-injuries.


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