The algae community in taxon Haptophyceae at the early bloom stage of Phaeocystis globosa in Northern Beibu Gulf in winter

Phaeocystis globosa (Order Phaeocystales, family Phaeocystaceae) caused significant impact on aquaculture farming, global climate change and industry. Since the year 2010, intensive red tides of P. globosa began to appear in Beibu Gulf, where previously free of harmful algal blooms, and posed great threats to the cooling systems of a nuclear power plant in 2014 and 2015. In order to discover the bloom mechanism, the community structure of marine microalgae, with a focus on Haptophyceae taxa, in winter in the northern Beibu Gulf near the Qinzhou Bay, Sanniang Bay (SNB) and Dafenjiang River Estuary (DRE), were explored via 18S ribosomal DNA analysis of the V4 region using the Illumina-Based Sequencing platform. The correlation between the relative abundance of five kinds of Haptophyceae algae and environmental factors of seawater were analyzed. The most abundant Haptophyceae-related OTU in terms of number of reads was identified as Phaeocystis and Chrysochromulina. The abundance for other Haptophyceae class was relatively low, such as Haptolina, Prymnesium and Isochrysis. Phaeocystis was present in all samples sites except S6, S11, S12, S14 and S15, and particularly abundant at S8, nearly 29 times more than the second most abundant site. Most notably, the results showed that Phaeocystis displayed highly positive linear correlation with the concentration of NO3--N (Pearson r=0.856, p<0.01). Linear regression analysis indicated that Phaeocystis was significantly linearly related to the NO3--N (R2=0.732; Y=-0.005 + 0.410*X, Y is the relative abundance of P.globosa, X is the concentration of NO3--N; F=38.227, P<0.05) and NO3--N has a significant positive effect on P.globosa (regression coefficient is 0.410, P=0.000). Moreover, the relative abundance of Phaeocystis was significant related to temperature of sea water (Pearson r=-0.882,p<0.01). Water temperature can explain the 77.8% change reason for the P.globosa (R2=0.778), and has a significant effect on P. globosa (Y=0.169-0.009*X, F=49.031,P<0.05), and the regression coefficient is -0.009 (P=0.000) which indicated a significant negative impact relationship between them. Our high throughput sequencing (HTS) based research illustrated how the P. globosa bloom generated and its relationship with NO3--N and temperature of sea water in northern Beibu Gulf for the first time, and bringing hope for solving this big problem.

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Removal effect of algicidal modified clay on Phaeocystis globosa blooms in culturing enclosure experiments: A short communication

IOP Conference Series Earth and Environmental Science ◽

10.1088/1755-1315/869/1/012068 ◽

2021 ◽

Vol 869 (1) ◽

pp. 012068

Author(s):

X Qin ◽

X Chen ◽

F Li ◽

H Ya ◽

D Zhu ◽

...

Keyword(s):

Harmful Algal Blooms ◽

Algal Blooms ◽

Control Group ◽

Beibu Gulf ◽

Blank Control Group ◽

Phaeocystis Globosa ◽

Marine Aquaculture ◽

Modified Clay ◽

The Past ◽

Field Culture

Abstract With the increased scale of marine aquaculture in the Beibu Gulf, as well as accelerating urbanization and industrialization, frequent harmful algal blooms (HABs) have occurred in this area, especially those formed by Phaeocystis globosa in the past several years. As the P. globosa bloom has been a serious marine ecological disaster in the Beibu Gulf, research on quick and effective methods to eliminate P. globosa blooms is a hot research topic. In this study, the bacteria Streptomyces yatensis B4503 combined with modified diatomite was used to prepare algicidal modified clay, which was then used to study the removal effect on P. globosa blooms in field culture enclosures. The results showed that after 6 h of treatment with algicidal modified clay, compared with the blank control group, the cell density and chlorophyll a content of P. globosa decreased by 26.86% and 64.03%, respectively, and they decreased by 75.23% and 84.81%, respectively, after 24 h. The study indicated that algicidal modified clay can be applied to eliminate HABs caused by P. globosa in coastal water.

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The Effect of Aggregate-Forming Minerals on Thermodynamic Parameters Using Surface Free Energy Concept and Its Relationship with the Moisture Susceptibility of Asphalt Mixtures

Advances in Civil Engineering ◽

10.1155/2021/8818681 ◽

2021 ◽

Vol 2021 ◽

pp. 1-15

Author(s):

Gholam Hossein Hamedi ◽

Mohammad Reza Esmaeeli ◽

Vahid Najafi Moghaddam Gilani ◽

Seyed Mohsen Hosseinian

Keyword(s):

Free Energy ◽

Surface Free Energy ◽

Regression Coefficient ◽

Negative Impact ◽

Positive Impact ◽

Linear Regression Analysis ◽

Asphalt Mixtures ◽

Rate Of Change ◽

Moisture Susceptibility ◽

Adhesion Properties

Moisture damage is known to be a key factor influencing the durability of asphalt pavements. This phenomenon will reduce the mechanical properties of asphalt mixtures due to its destructive effects on the adhesion of the bitumen-aggregate system and the cohesion of the bitumen membrane. The mineral properties of the aggregates of asphalt mixtures are one of the factors affecting moisture susceptibility. Therefore, the surface free energy (SFE) method, as one of the thermodynamic methods, and indirect tensile strength test (ITST) have been used to determine the failure mechanism and the rate of change of adhesion properties of asphalt mixtures under the influence of mineralogical characteristics. Prior to the above tests, an X-ray fluorescence spectrometry (XRF) test was performed to identify aggregate-forming minerals in eight different types of aggregates with various minerals from eight mines, and also the apparent bitumen film thickness was measured. XRF test results showed that most parts of the aggregates in mines 1– 6 were composed of SiO2, which had strong acidic properties, according to the SFE results. ITST results showed that samples constructed with aggregates of mine 7 and 8 (with high CaO mineral content) experienced a higher TSR than other mixtures in all freeze-thaw (F-T) cycles. Results of the SFE method showed that aggregates with more calcareous properties had a smaller acidic component and a larger basic component. In mines 7 and 8, where the nonpolar component of their aggregates was larger, the tendency of the aggregates to adherence and wettability by water decreased. The adhesion free energy (AFE) between bitumen and aggregates with higher CaO and less SiO2 amounts was more than AFE between bitumen and aggregates with lower CaO and higher SiO2 amounts, in dry conditions. The presence of higher amounts of CaO in aggregates increased AFE of bitumen-aggregate in presence of water from a negative value to zero. In linear regression analysis, due to the positive regression coefficient of the CaO mineral, this mineral had a positive impact on TSR; on the other hand, due to the negative regression coefficient of the SiO2 mineral, this mineral had a negative impact on the TSR of asphalt mixtures.

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Transformation Kinetics of Burnt Lime in Freshwater and Sea Water

Materials ◽

10.3390/ma13214926 ◽

2020 ◽

Vol 13 (21) ◽

pp. 4926

Author(s):

Harald Justnes ◽

Carlos Escudero-Oñate ◽

Øyvind Aaberg Garmo ◽

Martin Mengede

Keyword(s):

Calcium Hydroxide ◽

Magnesium Hydroxide ◽

Open System ◽

Algal Blooms ◽

Sea Water ◽

Negative Impact ◽

Particle Surface ◽

Burnt Lime ◽

Green Algal ◽

Kinetics Of

Calcium oxide (CaO), also known as burnt lime, is being considered as a possible treatment to reduce the negative impact of sea urchins on tare forests in northern coastal waters and blue-green algal blooms in the surrounding of fish-farms. In this respect, the reaction kinetics of burnt lime in contact with sea water has been elucidated and compared to its behaviour in fresh water. In the first minutes of contact between burnt lime and water, it “slaked” as CaO reacted with water to yield calcium hydroxide (Ca(OH)2). Subsequently, calcium hydroxide reacted with magnesium, sulphate and carbonate from the sea water to yield magnesium hydroxide (Mg(OH)2), calcium sulphate dihydrate (gypsum, CaSO4·2H2O) and calcium carbonate (CaCO3), respectively. In a closed system of 1% CaO in natural sea water (where the supply of sulphate, magnesium and carbonate is limited), more than 90% reacted within the first 5 h. It is foreseen that in an open system, like a marine fjord, it will react even faster. The pH 8 of sea water close to the CaO particle surface will immediately increase to a theoretical value of about 12.5 but will, in an open system with large excess of sea water, rapidly fall back to pH 10.5 being equilibrium pH of magnesium hydroxide. This is further reduced to <9 due to the common ion effect of dissolved magnesium in sea water and then be diluted to the sea water background pH, about 8. Field test dosing CaO particles to sea water showed that the pH of water between the particles stayed around 8.

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Factors Affecting the Failure of Patient Safety Target Indicators in the Regional Hospital of the Datu Beru Takengon Central Aceh

Journal of Asian Multicultural Research for Medical and Health Science Study ◽

10.47616/jamrmhss.v1i2.29 ◽

2020 ◽

Vol 1 (2) ◽

pp. 40-52

Author(s):

Ainal Mardiah ◽

Mappeaty Nyorong ◽

Jamaluddin Jamaluddin

Keyword(s):

Patient Safety ◽

Linear Regression ◽

Multiple Linear Regression ◽

Communication Systems ◽

Safety Management ◽

Regression Coefficient ◽

Negative Impact ◽

Linear Regression Analysis ◽

Dominant Factor ◽

Cross Sectional

The application of patient safety management is very important in an effort to prevent or minimize the occurrence of adverse patient safety incidents. The purpose of this study was to identify the factors that influence the achievement of patient safety target indicators. The method is a quantitative observational study with a cross sectional study approach. The study population was a nurse who worked in the inpatient room with a sample of 60 people who were taken by purposive sampling. The statistical test used is Multiple Linear Regression Analysis. The results of the Multiple Linear Regression Test show that knowledge, communication systems, commitment and experience (regression coefficient values of 0.164, 1.1192, 0.528 and 1.169 have a positive influence on the achievement of patient safety goal indicators and leadership, risk management systems and reporting systems have a significant influence. negative impact on the achievement of patient safety target indicators (regression coefficient values of -0.064, - 0.967 and -0.281). The results of the t test were obtained that the communication system is the dominant factor that has a significant effect on the achievement of the patient safety goal indicators. significant towards the achievement of patient safety target indicators.It is expected that input or consideration for the hospital in evaluating and improving hospital policies in increasing the achievement of patient safety target indicators is in accordance with existing targets.

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The Ecological Responses of Bacterioplankton During a Phaeocystis Globosa Bloom in Beibu Gulf, China Highlighted by Integrated Metagenomics and Metatranscriptomics

10.21203/rs.3.rs-1011939/v1 ◽

2021 ◽

Author(s):

sha xu ◽

Cheng He ◽

Zhenjun Kang ◽

Shuqun Song ◽

Caiwen Li

Keyword(s):

Bacterial Community ◽

Algal Blooms ◽

Molecular Data ◽

Field Investigation ◽

Beibu Gulf ◽

Phaeocystis Globosa ◽

Extracellular Secretion ◽

Depth Analysis ◽

The Difference ◽

Microbial Groups

Abstract The interaction between bacteria and phytoplankton during bloom events are complicated throughout the developmental processes of algal blooms. The detailed ecological roles of bacterioplankton during algal blooms still need to be investigated comprehensively. With the assistance of omics techniques, the composition and function of bacterioplankton were studied during the blooming and recession periods of Phaeocystis globosa in the Beibu Gulf, China. The transcriptionally active taxa of Vibrio, which correlated with most functional genes, were enriched in the blooming period, whereas the active microbial groups, such as Erythrobacter and Candidatus puniceispirillum, increased significantly in the recession period of the P. globosa bloom. The transcriptional analyses indicated the blooming and recession periods of P. globosa had different impacts on the function of bacterioplankton, including shifts in expression of specific metabolic pathways for variable nutritional utilization and their advantage in bacterial motility, quorum sensing, and extracellular secretion. Overall, the integrated field investigation and in-depth analysis of molecular data highlighted the difference of bacterial community during the outbreak and collapse stages of P. globosa bloom, and provided fundamental data for better understanding of the bacterial community in response to blooming and recession of the P. globosa bloom.

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PENGARUH KEPEMIMPINAN TRANSFORMASIONAL, KEPUASAN KERJA, KEPERCAYAAN KEPADA PEMIMPIN TERHADAP KETERIKATAN KERJA KARYAWAN PADA PT. BALI BIJAKSANA NUSA DUA – BALI

MEDIA BINA ILMIAH ◽

10.33758/mbi.v14i4.356 ◽

2019 ◽

Vol 14 (4) ◽

pp. 2455

Author(s):

I Putu Dharmawan Pradhana ◽

Putu Nova Kusuma Hendra

Keyword(s):

Job Satisfaction ◽

Transformational Leadership ◽

Employee Engagement ◽

Regression Coefficient ◽

Linear Regression Analysis ◽

Simple Random Sampling ◽

Multiple Linear Regression Analysis ◽

Coefficient Of Determination ◽

Positive Effects ◽

Trust In Leaders

The purpose of this study was to determine the effect of transformational leadership, job satisfaction, trust in leaders on employee engagement at PT.Bali Bijaksana Nusa Dua – Bali. The number of samples in this study were 75 employees with a simple random sampling method. Data collection used questionnaire. The data analysis technique used is the classical assumption test, multiple linear regression analysis, t-test, F-test and test coefficient of determination. The results of the study show that there are positive and partial positive effects of transformational leadership, job satisfaction, and trust in leaders in increasing employee engagement at PT. Bali Bijaksana Nusa Dua – Bali. The results showed that the transformational leadership regression coefficient (X1) was 0.268 with a value that meant that each increase in transformational leadership variables could increase employee engagement at PT. Bali Bijaksana Nusa Dua – Bali. Job satisfaction regression coefficient (X2) is equal to 0.303, which means that every increase in job satisfaction variables can increase employee engagement at PT. Bali Bijaksana Nusa Dua – Bali. Regression coefficient value to leader (X3) is equal to 0.256, which means that every increase in the trust variable in the leader can increase employee engagement at PT. Bali Bijaksana Nusa Dua – Bali. As the results of the determination coefficient of 0.657, its means that 65.7% can explain the model or influence of each variable on work engagement, while the rest (100% -65.7% = 34,3%) is explained by other reasons outside research model.

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Investigational Studies on Quantity of Salinity in Netravati River Estuary Sand-Coastal Karnataka

International Journal of Emerging Research in Management and Technology ◽

10.23956/ijermt.v6i6.243 ◽

2018 ◽

Vol 6 (6) ◽

pp. 46

Author(s):

Raveesha P ◽

K. E. Prakash ◽

B. T. Suresh Babu

Keyword(s):

Brackish Water ◽

Sea Water ◽

Salt Water ◽

Construction Material ◽

Salt Content ◽

River Estuary ◽

Sand Sample ◽

River Sand ◽

Natural Aggregates

The salt water mixes with fresh water and forms brackish water. The brackish water contains some quantity of salt, but not equal to sea water. Salinity determines the geographic distribution of the number of marshes found in estuary. Hence salinity is a very important environmental factor in estuary system. Sand is one major natural aggregate, required in construction industry mainly for the manufacture of concrete. The availability of good river sand is reduced due to salinity. The quality of sand available from estuarine regions is adversely affected due to this reason. It is the responsibility of engineers to check the quality of sand and its strength parameters before using it for any construction purpose. Presence of salt content in natural aggregates or manufactured aggregates is the cause for corrosion in steel. In this study the amount of salinity present in estuary sand was determined. Three different methods were used to determine the salinity in different seasonal variations. The sand sample collected nearer to the sea was found to be high in salinity in all methods. It can be concluded that care should be taken before we use estuary sand as a construction material due to the presence of salinity.

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DIVERSITY OF FISH LARVAE AROUND THE ESTUARY OF THE BANYUASIN RIVER, SOUTH SUMATERA PROVINCE

BIOVALENTIA Biological Research Journal ◽

10.24233/biov.6.2.2020.181 ◽

2020 ◽

Vol 6 (2) ◽

Author(s):

Moh. Rasyid Ridho ◽

Enggar Patriono ◽

Sarno Sarno ◽

Sahira Wirda

Keyword(s):

Initial Phase ◽

Sampling Method ◽

Environmental Changes ◽

Negative Impact ◽

Fish Larvae ◽

River Estuary ◽

Sampling Technique ◽

Critical Phase ◽

Morisita Index ◽

Index Value

The initial phase of the fish life cycle is a critical phase associated with high mortality due to sensitivity to predators, food availability, and also environmental changes that occur in nature. Disruption of the initial stages of fish life has a negative impact on fish populations. Until now there has been no information about fish larvae around the Banyuasin River Estuary. Therefore, research is needed on the diversity of fish larvae around the Banyuasin River Estuary, South Sumatra Province. This research were used purposive sampling method, sampling technique in the form of Cruise Track Design with continuous parallel survey trajectory. Based on the results of the study found as many as 10 families consisting of 1483 individuals of fish larvae in March and 1013 individuals of fish larvae in May consisting of Engraulidae 1,601 individuals of fish larvae, Mungiloidei as many as 109 individuals, Leiognathidae 50 individuals, Chanidae 453 individuals, Scatophagidae 20 individuals , Belonidae 39 individuals, Gobioididae 5 individuals, Chandidae 183 individuals, Syngnatihidae 6 individuals, and Gobiidae 30 individuals fish larvae. The index value of fish larvae diversity is classified as medium category (March 1.02 and May 1.12), Morisita index shows the distribution pattern of fish larvae classified as a group (March 0-14.17 and May 2.43-10.40 ), and the evenness index value is in the medium category (March 0.437 and May 0.521).

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Bacterial die-away rates in red sea waters

Water Science & Technology ◽

10.2166/wst.1995.0071 ◽

1995 ◽

Vol 32 (2) ◽

pp. 45-52 ◽

Cited By ~ 2

Author(s):

H. Z. Sarikaya ◽

A. M. Saatçi

Keyword(s):

Solar Radiation ◽

Decay Rate ◽

Sea Water ◽

Membrane Filter ◽

Linear Regression Analysis ◽

Total Coliform ◽

Coliform Bacteria ◽

Decay Rate Constant ◽

Solar Intensity ◽

Log Normal

Total coliform bacteria have been chosen as the indicator organism. Coliform die-away experiments have been carried out in unpolluted sea water samples collected at about 100 m off the coastline and under controlled environmental conditions. The samples were transformed into one litre clean glass beakers which were kept at constant temperature and were exposed to the solar radiation. The membrane filter technique was used for the coliform analysis. The temperature ranged from 20 to 40° C and the dilution ratios ranged from 1/50 to 1/200. Coliform decay rate in the light has been expressed as the summation of the coliform decay rate in the dark and the decay rate due to solar radiation. The solar radiation required for 90 percent coliform removal has been found to range from 17 cal/cm2 to 40 cal/cm2 within the temperature range of 25 to 30° C. Applying the linear regression analysis two different equations have been given for the high (I>10 cal/cm2.hour) and low solar intensity ranges in order to determine the coliform decay rate constant as a function of the solar intensity. T-90 values in the light have been found to follow log-normal distribution with a median T-90 value of 32 minutes. The corresponding T-90 values in the dark were found to be 70-80 times longer. Coliform decay rate in the dark has been correlated with the temperature.

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