Density and de-nitrifying potential of indigenous bacterial assemblage in mangrove and seagrass in the North of Vietnam

This study assessed the density and de-nitrification potential of indigenous microorganisms in mangroves and seagrass beds in northern Vietnam through two mangrove ecosystems in Tien Yen - Quang Ninh and Bang La - Hai Phong and three seagrass beds in Ha Coi and Dam Ha - Quang Ninh and Tam Giang - Thua Thien Hue. The analysis results of 4 sampling times in rainy and dry seasons during 2017–2019 showed that the density of de-nitrifying bacteria ranged from (1.0 × 102)–(4.6 × 103) MPN/mL, averaging 1.1 ± 0.3 × 103 MPN/mL. The density in mangroves was higher than that in seagrass (a = 0.05). De-nitrification rates ranged from 0.0 µgN/wet to 69.0 µgN/wet soil g/hour, averaging 18.4 ± 7.4 µgN/wet soil g/hour. The rate at the experiments added 0.5 mgN/L in seagrass was higher than that in the mangrove. The density and rate of de-nitrification were significantly correlated with many environmental factors, especially density of sulfur-oxidizing bacteria, the density of nitrifying bacteria, pH, Eh, Nts, N-NH4, P- PO4 and BOD5.

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Density and nitrifying potential of indigenous bacterial community in mangrove and seagrass in the north of Vietnam

Tạp chí Khoa học và Công nghệ Biển ◽

10.15625/1859-3097/15787 ◽

2020 ◽

Vol 20 (4) ◽

pp. 437-445

Author(s):

Le Thanh Huyen ◽

Dao Thi Anh Tuyet ◽

Le Minh Hiep ◽

Nguyen Tien Dat ◽

Ha Thi Binh ◽

...

Keyword(s):

Bacterial Community ◽

Average Density ◽

Nitrifying Bacteria ◽

Seagrass Beds ◽

The North ◽

Indigenous Microorganism ◽

Dry Seasons ◽

Quang Ninh ◽

Sampling Times ◽

Dry And Rainy Seasons

Density and nitrification potential of indigenous microorganism in mangroves (Tien Yen - Quang Ninh and Bang La - Hai Phong) and seagrass (Ha Coi, Dam Ha - Quang Ninh and Tam Giang - Thua Thien Hue) in the north of Vietnam were evaluated through 4 sampling times in the dry and rainy seasons in the years of 2017-2019. The analytical results showed that the average density of nitrifying bacteria was 4.6 ± 1.8 × 102 MPN/ml, in which the density in mangroves tended to be higher than that in the seagrass beds (P < 0.05) in both the rainy and dry seasons. The average nitrifying rate was 2.7 ± 0.6 µgN/g wet soil/hour, in which the rate in mangroves tended to be higher than that in seagrass beds in the rainy season (P < 0.05). Nitrifying density and rate are not only correlated with substrate concentration but also with other environmental factors such as P-PO4, BOD5, total phosphate in sediment and total bacterial density.

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Effects of Environmental Factors and Husbandry Practices on Summer Mortality Events in the Cultivated Pacific Oyster Crassostrea gigas in the North of Ireland

Journal of Shellfish Research ◽

10.2983/035.039.0102 ◽

2020 ◽

Vol 39 (1) ◽

pp. 13

Author(s):

Elizabeth C. Ashton ◽

Simon Guist ◽

Dai Roberts ◽

Julia D. Sigwart

Keyword(s):

Environmental Factors ◽

Crassostrea Gigas ◽

Pacific Oyster ◽

The North ◽

Summer Mortality ◽

Husbandry Practices

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An inter-dependence of flood and drought: disentangling amphibian beta diversity in seasonal floodplains

Marine and Freshwater Research ◽

10.1071/mf16391 ◽

2017 ◽

Vol 68 (11) ◽

pp. 2115 ◽

Cited By ~ 2

Author(s):

Leonardo F. B. Moreira ◽

Tainá F. Dorado-Rodrigues ◽

Vanda L. Ferreira ◽

Christine Strüssmann

Keyword(s):

Community Structure ◽

Environmental Factors ◽

Quantitative Data ◽

Explanatory Variable ◽

Biotic Interactions ◽

Ecological Role ◽

Β Diversity ◽

Amphibian Community ◽

Dry Seasons

Species composition in floodplains is often affected by different structuring factors. Although floods play a key ecological role, habitat selection in the dry periods may blur patterns of biodiversity distribution. Here, we employed a partitioning framework to investigate the contribution of turnover and nestedness to β-diversity patterns in non-arboreal amphibians from southern Pantanal ecoregion. We investigated whether components of β-diversity change by spatial and environmental factors. We sampled grasslands and dense arboreal savannas distributed in 12 sampling sites across rainy and dry seasons, and analysed species dissimilarities using quantitative data. In the savannas, both turnover and nestedness contributed similarly to β diversity. However, we found that β diversity is driven essentially by turnover, in the grasslands. In the rainy season, balanced variation in abundance was more related to altitude and factors that induce spatial patterns, whereas dissimilarities were not related to any explanatory variable during dry season. In the Pantanal ecoregion, amphibian assemblages are influenced by a variety of seasonal constraints on terrestrial movements and biotic interactions. Our findings highlighted the role of guild-specific patterns and indicated that mass effects are important mechanisms creating amphibian community structure in the Pantanal.

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Suspended sediment distribution under varied currents in the largest river-connected lake of China

Water Science & Technology Water Supply ◽

10.2166/ws.2017.167 ◽

2017 ◽

Vol 18 (3) ◽

pp. 994-1004 ◽

Cited By ~ 3

Author(s):

Hua Wang ◽

Yijun Zhao ◽

Fengnian Zhou ◽

Huaiyu Yan ◽

Yanqing Deng ◽

...

Keyword(s):

Flow Pattern ◽

Suspended Sediment ◽

Flow Patterns ◽

Field Investigation ◽

Gravity Flow ◽

Shear Stresses ◽

Sediment Distribution ◽

Back Flow ◽

The North ◽

Dry Seasons

Abstract Poyang Lake was selected as the research area. Based on laboratory experiment, field investigation and numerical simulation, the spatial distributions of suspended sediment (SS) under the gravity-flow, jacking-flow and back-flow patterns were quantitatively analysed. An annular flume experiment was conducted to determine the critical starting shear stresses of the sediments in the flood and dry seasons. By numerical experiment, the SS transport under different flow patterns was explored. Several results stand out. (1) The critical starting shear stresses of the sediments in the flood and dry seasons were 0.35 N·m−2 and 0.29 N·m−2, respectively. (2) Due to the strongest flow disturbance and scouring effect, SS under the gravity-flow pattern was characterized by the highest loads. The lowest SS was observed during the jacking-flow pattern, which could be attributed to the lowest water level gap between the lake and external rivers. The loads ranged from 0.053 kg·m−3 to 0.068 kg·m−3. (3) Under the back-flow pattern, SS in the north lake was evidently influenced by the Yangtze River, and the mean value was approximately 0.12 kg·m−3. With the gradually weakened back-flow impact, the SS load was decreased from the north to the middle of the lake.

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Investigation on Eutrophication Level for Gucheng Lake by the Model of Butterfly Catastrophe

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.726-731.2051 ◽

2013 ◽

Vol 726-731 ◽

pp. 2051-2056

Author(s):

Hua Wang ◽

Yi Yi Zhou ◽

Feng Qiang Ji

Keyword(s):

Fuzzy Membership ◽

Ecological Indicator ◽

Pollution Load ◽

The South ◽

Flood Season ◽

The North ◽

Gucheng Lake ◽

Dry Seasons ◽

Membership Value ◽

Water Eutrophication

Based on the field measured results in the typical periods of flood season and dry season of Gucheng Lake, the present eutrophication levels of the lake were investigated by the Model of Butterfly Catastrophe, in which series of the environmental factors were considered including the ecological indicator of chlorophylla, the nutrient indicator of total nitrogen and total phosphorus, and the physical index of water transparency. The results showed that: the water eutrophication levels of Gucheng Lake were mal-distributed in space and time; the lake eutrophication tendency in flood seasons were more obvious than that in dry seasons; the eutrophication levels in the south part of the lake were relatively lower than that in the north and the average comprehensive mutation of fuzzy membership value in the south was about 0.3006 in the dry seasons. Due to the increased pollution load and the hydrodynamic conditions, the eutrophication degree in the estuary areas were higher and the fuzzy membership value was close to 0.235, achieving the medium eutrophication level.

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MS prevalence in New Zealand, an ethnically and latitudinally diverse country

Multiple Sclerosis Journal ◽

10.1177/1352458510379614 ◽

2010 ◽

Vol 16 (12) ◽

pp. 1422-1431 ◽

Cited By ~ 54

Author(s):

Bruce V Taylor ◽

John F Pearson ◽

Glynnis Clarke ◽

Deborah F Mason ◽

David A Abernethy ◽

...

Keyword(s):

New Zealand ◽

Environmental Factors ◽

Latitudinal Gradient ◽

Population Level ◽

Cross Sectional Study ◽

European Population ◽

Multiple Sources ◽

Cross Sectional ◽

The North ◽

Mcdonald Criteria

Background: The prevalence of multiple sclerosis (MS) is not uniform, with a latitudinal gradient of prevalence present in most studies. Understanding the drivers of this gradient may allow a better understanding of the environmental factors involved in MS pathogenesis. Method: The New Zealand national MS prevalence study (NZMSPS) is a cross-sectional study of people with definite MS (DMS) (McDonald criteria 2005) resident in New Zealand on census night, 7 March 2006, utilizing multiple sources of notification. Capture—recapture analysis (CRA) was used to estimate missing cases. Results: Of 2917 people with DMS identified, the crude prevalence was 72.4 per 100,000 population, and 73.1 per 100,000 when age-standardized to the European population. CRA estimated that 96.7% of cases were identified. A latitudinal gradient was seen with MS prevalence increasing three-fold from the North (35°S) to the South (48°S). The gradient was non-uniform; females with relapsing—remitting/secondary-progressive (RRMS/SPMS) disease have a gradient 11 times greater than males with primary-progressive MS ( p < 1 × 10-7). DMS was significantly less common among those of Māori ethnicity. Conclusions: This study confirms the presence of a robust latitudinal gradient of MS prevalence in New Zealand. This gradient is largely driven by European females with the RRMS/SPMS phenotype. These results indicate that the environmental factors that underlie the latitudinal gradient act differentially by gender, ethnicity and MS phenotype. A better understanding of these factors may allow more targeted MS therapies aimed at modifiable environmental triggers at the population level.

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Memory impairments and its interaction with environmental factors in children aged 6 to 8 years living in gharb plain (N-w of Morocco)

European Psychiatry ◽

10.1016/s0924-9338(11)71974-5 ◽

2011 ◽

Vol 26 (S2) ◽

pp. 264-264 ◽

Cited By ~ 1

Author(s):

F.-Z. Azzaoui ◽

H. Hami ◽

A.O.T. Ahami

Keyword(s):

Working Memory ◽

Environmental Factors ◽

Building Materials ◽

Short Term Memory ◽

Rural Children ◽

Short Term ◽

Term Memory ◽

North West ◽

Memory Impairments ◽

The North

IntroductionThe “Gharb” plain (area of our study) localized in the North-West of Morocco is one of the most important agricultural and industrial regions of the Kingdom. Unfortunately, it suffered from the increase of different polluting human activities which expose the population, especially children, to serious neurobehavioral problems.Objective and aimsEvaluation of the short term memory and working memory in urban, periurban and rural schooled children (aged 6 to 8 years) living in Gharb plain and studying the relationship between the performance in this test and the quality of environment.MethodsMemory Sub-test of WISC III (Wechsler Intelligence Scale for Children) and questionnaire about some environmental conditions.ResultsThe obtained results had shown that 3,64% periurban children and 3,03% rural children suffer from short memory impairments and no impairments in urban children were registered. For working memory, 21,05%, 47,06% and 66,67% of impairments were found in urban, periurban and rural children respectively.Moreover, a significant correlations between the performances of short term memory and building materials (p < 0.05), source of pollution near the school (p < 0.05), and consumption of well water (p < 0.001) were registered.ConclusionsThe memory impairments recorded in these children appeared in connection with environmental factors, but a deeper investigation is needed for studying all these factors, in addition to others (psychological, socio-economical, and nutritional) ones.

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Otolith increments in European plaice (Pleuronectes platessa) reveal temperature and density-dependent effects on growth

ICES Journal of Marine Science ◽

10.1093/icesjms/fsy011 ◽

2018 ◽

Vol 75 (5) ◽

pp. 1655-1663 ◽

Cited By ~ 8

Author(s):

Peter van der Sleen ◽

Christoph Stransky ◽

John R Morrongiello ◽

Holger Haslob ◽

Melita Peharda ◽

...

Keyword(s):

Environmental Factors ◽

North Sea ◽

Bottom Temperature ◽

Growth Data ◽

Mixed Effect ◽

Pleuronectes Platessa ◽

Growing Season Length ◽

The North ◽

Growth Variation ◽

The North Sea

Abstract European plaice (Pleuronectes platessa) is a commercially important flatfish species in the North Sea. Yet, the environmental factors that affect the growth of plaice remain unresolved. Here we examine the drivers of plaice growth variation by using a large archive of otoliths from female plaice collected in the northeastern part of the North Sea from 1993 to 2015, providing growth data over the period 1985–2014. We developed a series of increasingly complex mixed-effect models to explore intrinsic (within individual) and extrinsic (environmental factors: bottom temperature and plaice density) sources of growth variation. We analysed juvenile (0 and 1 year) and (sub)adult (≥2 years) growth separately due to different habitat utilization across life stages. Juvenile growth was positively correlated with bottom temperature, whereas growth of adults was negatively correlated with bottom temperature. Correlations for both were strongest during autumn (September to October). For juveniles, the temperature–growth relationship likely reflects a response to growing season length while for adults it could reflect temperature-dependent changes to metabolic rate or food availability. For both juveniles and adults, we also found inverse relationship between population density and growth. We suggest that the approach used in this study can find a much wider application in European waters.

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Study on Dynamic Changes of Soil Erosion in the North and South Mountains of Lanzhou

10.21203/rs.3.rs-512984/v1 ◽

2021 ◽

Author(s):

Hua Zhang ◽

Jinping Lei ◽

Cungang Xu ◽

Yuxin Yin

Keyword(s):

Soil Erosion ◽

Environmental Factors ◽

Water Area ◽

Vegetation Coverage ◽

Dynamic Changes ◽

The North ◽

Joint Influence ◽

Bare Land ◽

Temporal And Spatial ◽

North And South

Abstract This study takes the north and south mountains of Lanzhou as the study area, calculates the soil erosion modulus of the north and south mountains of Lanzhou based on the five major soil erosion factors in the RUSLE model and analyzes the temporal and spatial dynamic changes of soil erosion and the characteristics of soil erosion under different environmental factors. The results show that the soil erosion intensity of the north and south mountains of Lanzhou is mainly micro erosion in 1995, 2000, 2005, 2010, 2015 and 2018. They are distributed in the northwest and southeast of the north and south mountains. Under different environmental factors, the soil erosion modulus first increased and then decreased with the increase of altitude; the soil erosion modulus increased with the increase of slope; the average soil erosion modulus of grassland and woodland was larger, and the average soil erosion modulus of water area was the smallest; except for bare land, the average soil erosion modulus decreased with the increase of vegetation coverage. The soil erosion modulus in the greening range is lower than that outside the greening scope, mainly the result of the joint influence of precipitation, soil and vegetation.

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