scholarly journals Role of Microbial Communities in the Weathering and Stalactite Formation in Karst Topography

2019 ◽  
Author(s):  
Tung-Yi Huang ◽  
Bing-Mu Hsu ◽  
Cheng-Wei Fan ◽  
Hsin-Chi Tsai ◽  
Chien-Yi Tung ◽  
...  
Keyword(s):  
Sequence Similarity ◽  
Outer Wall ◽  
Physical Parameters ◽  
Physical Factors ◽  
Organic Carbon Content ◽  
Light Penetration ◽  
Calcite Precipitation ◽  
Associated Bacteria ◽  
Coralline Limestone ◽  
Limestone Weathering

Abstract. This study investigated the long-term effect of environmental physical factors on the relative abundance of bacteria and the consequential landscape evolution in karst topography, focusing mainly on the effects of limestone weathering and calcite precipitation. The Narrow-Sky located in the upper part of Takangshan is a small gulch of Pleistocene coralline limestone formation in southern Taiwan. The landscapes were different in the karst walls between the opening and the inner of gulch due to the variation of physical parameters such as sunlight penetration, humidity, and temperature. A metagenomic approach was used out to determine the relationship of microbial community structures on the landscapes in various habitats around the gulch, namely on the inner and outer limestone wall, the water collected from speleothems surface, and the ground soil at the outer wall. The total organic carbon content was measured in solid samples to evaluate the biomass of the habitats. Our results showed that the biomass of habitats in the opening of the gulch was two times higher than the that inside where light penetration was lower. We also found that speleothems only occurred at the inner wall inside the gulch, where the environment exhibited water drips running through the surface of speleothems and less light penetration. The metagenomics in each habitat was surveyed to measure the sequence similarity of operational taxonomic units relative to urease-producing bacteria and weathering-associated bacteria available in the National Center for Biotechnology Information database. Our data revealed that the metagenomics of the inner wall and water samples exhibited more sequences that were similar to those of urease-producing bacteria, whereas the outer wall showed more sequences that were similar to those of weathering-associated bacteria, suggesting that bacteria facilitated the formation of limestone weathering and calcite precipitation for various habitats. This study revealed the pivotal roles of microorganisms in governing the geological evolution of the limestone landscape.

Spatial variability of trace metals in Podzols of northern forest ecosystems: Sampling implications

2003 ◽  
Vol 83 (5) ◽  
pp. 581-587 ◽  
Author(s):  
J. D. MacDonald ◽  
W. H. Hendershot
Keyword(s):  
Trace Metals ◽  
Spatial Variability ◽  
Point Source ◽  
Forest Ecosystems ◽  
Physical Factors ◽  
Individual Plant ◽  
Forest Site ◽  
Organic Carbon Content ◽  
Metal Concentrations ◽  
Northern Forest

The concentrations of metals in soils are spatially heterogeneous and soil sampling carried out when studying metals in forest ecosystems is often inadequate. We examined the spatial variability of Cd, Cu, Mn, Ni, Pb and Zn in northern forest ecosystems on a transect with distance from two point source emitters with the goal of providing basic information about the distribution and variability of metals in these soils. Samples were taken under six sampling points at four depths from three experimental sites on each of the two transects. Soils were analysed for acid digestible metals, pH and organic carbon content. Standard deviation, coefficients of variation, mean and medians were analysed for each horizon of each site. It was observed that Cu and Mn variability is higher in closer proximity to the point source while the variability of Zn increased with decreasing soil pH. In Sudbury, emitted metals Ni and Cu accumulate together in soils, whereas in Rouyn-Noranda, with the exception of Cd and Zn, metal concentrations were not related in forest floors. Observations suggest that physical factors influencing where metals are deposited as well as the inherent variability in soil chemical characteristics, and the distance from the point source can all act together to result in high variability in soil metal concentrations in a single forest site. Sampling in the interest of relating vegetation metal concentrations or response to soil metals should be carried out on an individual plant basis with multiple samples taken for each individual. Soil samples taken at intervals of 1 to 1.7 m will provide relative error in estimating soil concentrations of 10% or 20%, respectively. Key words: Spatial variability, trace metals, podzolic soils, smelter emissions

Simulation of Thrombus Formation Process Using Lattice Boltzmann Method With Consideration of Adhesion Force to Wall

2010 ◽  
Author(s):  
Masaaki Tamagawa
Keyword(s):  
Lattice Boltzmann Method ◽  
Lattice Boltzmann ◽  
Adhesion Force ◽  
Thrombus Formation ◽  
Artificial Organs ◽  
Physical Parameters ◽  
Physical Factors ◽  
Blood Pumps ◽  
Boltzmann Method ◽  
Rotary Blood Pumps

Recently artificial organs, especially rotary blood pumps, have been developed in the worldwide, but in this development, thrombus occurs in the pumps. In general, the main physical factors of thrombus formation are considered to be shear rate, wall properties for blood’s adhesion. But, there are no proper CFD codes for predicting thrombus formations using physical parameters in shear flows. In this paper, new model for predicting thrombus formation by considering aggregation and adhesion force to the wall by lattice Boltzmann method is proposed, and the trend of thrombus’s adhesion to the wall can be simulated more adequately than that of previous one.

scholarly journals Study of Changes in Physical Parameters of compost and vermicompost of Eucalyptus leaf litters

2018 ◽  
Vol 4 (1) ◽  
pp. 34-40
Author(s):  
Ritu Nagar ◽  
Anurag Titov ◽  
Praveesh Bhati
Keyword(s):  
Moisture Content ◽  
Leaf Litter ◽  
Initial Temperature ◽  
Cattle Dung ◽  
Physical Parameters ◽  
Physical Factors ◽  
Eudrilus Eugeniae ◽  
Minimum Level ◽  
Metabolic Heat ◽  
Later Phase

Vermicompost and compost of leaf litter of Eucalyptus was studied in plastic bins in duplicate sets with two different proportions (100 % and 50 %). For vermicompost experiments, epigeic earthworm species Eisenia foetida and Eudrilus eugeniae were employed at 10-10 numbers each per vermicompost bins. Cattle dung was taken as control. During the entire process physical factors viz. temperature, pH, moisture content and biomass were measured and compaired. The results were reveal that initial temperature was 35°C ± 2°C in both vermicompost and compost leaf litter and after several weeks, it was set at minimum level. In 50 % leaf litter temperature was 2-3°C higher than 100 % leaf litter. pH of both vermicompost and compost mixtures were acidic in beginning phase while set at alkaline at final stage. Vermicompost had lower pH than compost. Moisture content of leaf litter also decreased in initial phase due to generation of metabolic heat but at later phase it was increased due to decreasing of metabolic heat. More changed was seen in 100 % leaf litter followed by 50 % and then cattle dung. Biomass of leaf litter was more decreased in 100 % waste then 50 % and cattle dung.

scholarly journals Beyond Slam: the DUF560 family outer membrane protein superfamily SPAM has distinct network subclusters that suggest a role in non-lipidated substrate transport and bacterial environmental adaptation

2020 ◽  
Author(s):  
Terra J. Mauer ◽  
Alex S. Grossman ◽  
Katrina T. Forest ◽  
Heidi Goodrich-Blair
Keyword(s):  
Host Range ◽  
Outer Membrane ◽  
Binding Protein ◽  
Sequence Similarity ◽  
Outer Membrane Proteins ◽  
Environmental Adaptation ◽  
Host Cells ◽  
Xenorhabdus Nematophila ◽  
Associated Bacteria ◽  
Host Phylogeny

AbstractIn host-associated bacteria, surface and secreted proteins mediate acquisition of nutrients, interactions with host cells, and specificity of host-range and tissue-localization. In Gram-negative bacteria, the mechanism by which many proteins cross, become embedded within, or become tethered to the outer membrane remains unclear. The domain of unknown function (DUF)560 occurs in outer membrane proteins found throughout and beyond the proteobacteria. Functionally characterized DUF560 representatives include NilB, a host-range specificity determinant of the nematode-mutualist Xenorhabdus nematophila and the surface lipoprotein assembly modulators (Slam), Slam1 and Slam2 which facilitate surface exposure of lipoproteins in the human pathogen Neisseria meningitidis. Through network analysis of protein sequence similarity we show that DUF560 subclusters exist and correspond with organism lifestyle rather than with taxonomy, suggesting a role for these proteins in environmental adaptation. Cluster 1 had the greatest number of representative proteins, was dominated by homologs from animal-associated symbionts, and was composed of subclusters: 1A (containing NilB, Slam1, and Slam2), 1B, and 1C. Genome neighborhood networks revealed that Cluster 1A DUF560 members are strongly associated with TonB, TonB-dependent receptors, and predicted co-receptors such as the Slam1 lipoprotein substrates transferrin binding protein and lactoferrin binding protein. The genome neighborhood network of Cluster 1B sequences are similarly dominated by TonB loci, but typically the associated co-receptors (the presumed DUF560 substrates) are predicted to be non-lipidated. We suggest that these subclusters within the DUF560 protein family indicate distinctive activities and that Slam activity may be characteristic of Cluster 1A members but not all DUF560 homologs. For Cluster 1 DUF560 homologs we propose the name SPAM (Surface/Secreted Protein Associated Outer Membrane Proteins) to accommodate the potential for non-lipoprotein substrates or different activities. We show that the repertoire of SPAM proteins in Xenorhabdus correlates with host phylogeny, suggesting that the host environment drives the evolution of these symbiont-encoded proteins. This pattern of selection for specific sequences based on host physiology and/or environmental factors may extend to other clusters of the DUF560 family.

scholarly journals Energy Efficient Routing based on Reliability for Mobile Ad hoc Network

2019 ◽  
Vol 8 (4) ◽  
pp. 5327-5330
Keyword(s):  
Ad Hoc ◽  
Mobile Ad Hoc Network ◽  
Data Communication ◽  
Physical Factor ◽  
Physical Parameters ◽  
Physical Factors ◽  
Quality Factors ◽  
Energy Efficient Routing ◽  
Performance Factors ◽  
And Performance

MANETs is a network which has nodes. Communication is done without use of infrastructure. Quality based routing is developed which considers end to end qualitatiove data communication. A number of protocols were designed and suggested by researchers to achieve effective communication in MANETs. Considering number of quality factors as energy, trust, bandwidth etc a number of protocols are existing. But still there are number of factors those can consider to enhance the performance of the protocols used for the communication purpose. The existing schemes were effective enough but still as factors those were considering only the resources held by a node not the physical factors were present as node is to survive and communication in network. So further enhancements were possible by considering the physical parameters. Inspired from that in this paper a proposed scheme considering physical factor name as Distance is considered as the improvement to the traditional scheme. The distance factor is behaving as finding the physical presence of the node in the network also the distance factor will help to find the appropriate node for the next hop to communicate. A simulation is conducted in MATLAB software and performance factors as throughput and energy are analyzed, also an comparison with existing system is done and the results shows that the proposed scheme is effective enough to achieve QOS based routing with reduced energy consumption and high throughput.

A Comparison of PCB Congener Distributions in Two Point-Source Contaminated Lakes and One Uncontaminated Lake in Ontario

1989 ◽  
Vol 24 (1) ◽  
pp. 23-46 ◽  
Author(s):  
C. R. Macdonald ◽  
C. D. Metcalfe
Keyword(s):  
Point Source ◽  
Yellow Perch ◽  
Water Solubility ◽  
Smallmouth Bass ◽  
Physical Factors ◽  
Organic Carbon Content ◽  
Substitution Pattern ◽  
Significant Difference ◽  
The Individual ◽  
High Organic Carbon Content

Abstract PCB congener accumulation in biota and sediments involves several processes, including physical factors characterized by octanol-water partition coefficients and water solubility, and chemical factors which are influenced by the degree of chlorination and the substitution pattern of the individual congeners. The present study was conducted to determine if PCB congeners are distributed in a consistent pattern in two lakes known to have received point-source contamination with PCBs, and a control lake with no known point source. Samples of 4 groups of biota, water and sediment indicated that each lake had a unique pattern of congener distribution which was probably related to the source of the contamination. A comparison of total and individual PCB congener concentrations within each study lake showed that no one species consistently contained the highest residues of PCBs. Smallmouth bass had the highest concentration of PCBs in Rice lake while yellow perch was highest in Lakes Clear and Scugog. Sediments contained lower concentrations of PCBs than biota and did not show enrichment of higher chlorinated congeners, despite having high organic carbon content. Within the contaminated lakes, young-of-the-year (YOY) and older yellow perch had the same congener pattern, and there was no significant difference in their PCB concentration. This indicates that equilibrium concentrations of PCBs are established rapidly in the young fish and that all congeners equilibrate at the same rate.

scholarly journals Impact of Brick Kilns’ Emission on Soil Quality of Agriculture Fields in the Vicinity of Selected Bhaktapur Area of Nepal

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Gunjan Bisht ◽  
Sanjila Neupane
Keyword(s):  
Heavy Metal ◽  
Soil Quality ◽  
Heavy Metal Contamination ◽  
Nutrient Content ◽  
Physical Parameters ◽  
Organic Carbon Content ◽  
Brick Kiln ◽  
Entire Study ◽  
Brick Kilns

The study was conducted to evaluate soil quality and impact of brick kiln on different physicochemical parameters of soils of agricultural field, located in the vicinity of Bhaktapur, Nepal. The study was carried out by determining the physicochemical characteristics of soil, soil fertility, and heavy metal contamination of soil. During the entire study period, water absorptivity of soil ranged from 2.4 to 3.3 mg/L, pH varies from 5.885 to 7.64, and organic carbon content and organic matter varied from 0.277 to 0.93%, from 0.477% to 1.603%, respectively. Nutrient content, that is, sulfate and nitrate concentration, in the soil ranged from 0.829 to 3.764 mol/L and from 0.984 to 29.99 mol/L, respectively. The findings revealed that concentrations of heavy metals (chromium and lead) were within permissible limit, although the levels were higher in soil at 50 m and decrease farther from brick kiln. However, the physical parameters and nutrient content were deficient in soil at 50 m while increasing gradually at distances of 100 m and 150 m. The variation of result obtained for physical parameters supports the fact that quality of soil in terms of heavy metal content and nutrient content was directly proportional to the distance from the kiln; that is, the quality of soil increased with increasing distance.

scholarly journals Classification of Different Blueberry Cultivars by Analysis of Physical Factors, Chemical and Nutritional Ingredients, and Antioxidant Capacities

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Juan Song ◽  
Qiong Shi ◽  
Si-Min Yan ◽  
Hai-Yan Fu ◽  
Si-Zhan Wu ◽  
...  
Keyword(s):  
Supervised Classification ◽  
Particle Swarm Optimization Algorithm ◽  
Principal Component ◽  
Physical Parameters ◽  
Physical Factors ◽  
Quality Indices ◽  
Quality Factors ◽  
Key Factors ◽  
Nutritional Components

Blueberry fruits of different cultivars are featured with different quality indices. In this work, three types of quality factors, including 6 physical parameters, 12 chemical and nutritional components, and 3 antioxidant indices, were measured to compare and classify blueberry fruits from 12 different cultivars in China. Using the autoscaled data of quality factors, unsupervised principal component analysis was performed for exploratory analysis of intercultivar differences and the influences of quality factors. A supervised classification method, partial least squares discriminant analysis (PLSDA), was combined with the global particle swarm optimization algorithm (PSO) and two multiclass strategies, one-versus-rest (OVR) and one-versus-one (OVO), to select discriminative quality factors and develop classification models of the 12 cultivars. As a result, OVO-PLSDA with 8 quality factors could achieve the classification accuracy of 0.915. This study will provide new insights into the quality variations and key factors among different blueberry cultivars.

Effects of some physical factors on the stability of collapsing stars

2014 ◽  
Vol 23 (10) ◽  
pp. 1450085 ◽  
Author(s):  
M. Sharif ◽  
M. Zaeem Ul Haq Bhatti
Keyword(s):  
Heat Flux ◽  
Shear Viscosity ◽  
Anisotropic Pressure ◽  
Physical Parameters ◽  
Physical Factors ◽  
Field Equations ◽  
Radiation Density ◽  
Instability Range ◽  
Instability Regions ◽  
The Stability

This paper formulates the instability regions of a general charged spherically symmetric matter distribution with anisotropic pressure, shear viscosity, radiation density and radial heat flux. Matching conditions are found by taking Reissner–Nordström–Vaidya spacetime as an exterior geometry. The perturbed forms of Einstein–Maxwell field equations and conservation laws are constructed to formulate the collapse equation. The instability regions are identified under N and pN limits for the stability analysis. We conclude that the adiabatic index identifies the instability range which depends upon physical parameters like anisotropic pressure, energy density, shear viscosity and electromagnetic field and heat flux but radiation density has no role.

scholarly journals Mapping of Landslide Hazard Distribution in Alo Watershed Gorontalo Regency

2020 ◽  
Vol 2 (1) ◽  
pp. 30-40
Author(s):  
Risman Jaya ◽  
Ahmad Syamsu Rijal
Keyword(s):  
Local Community ◽  
Public Works ◽  
Geographical Information ◽  
Physical Parameters ◽  
Physical Factors ◽  
Scoring Method ◽  
Watershed Area ◽  
Landslide Occurrence ◽  
Landslide Distribution ◽  
Hazard Distribution

Landslide occurrence can be influenced by physical factors and human activities. Thus, research related to the provision of information about landslide distribution in Alo watershed is needed as a basis in enhancing community preparedness in dealing with disasters. The method used in this study is the scoring method based on the Minister of Public Works Regulation No.22 / PRT / M / 2017 which is processed through a geographical information system through the overlay of all physical parameters. The result shows that the Alo watershed area is divided into three vulnerability categories. "Low" category covers 7171.8 ha, "medium" category covers 12008.7 ha, and "high" category covers 5039.5 ha out of 24.221 ha the total area of Alo watershed. Information provided in this research is expected to be able to help the local government in making policies in managing the Alo watershed area and enhancing the understanding of the local community in Alo watershed in dealing with disasters.

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