An analysis of variability in the activity of nitrifiers in a soil under pasture .II. Some problems in the geostatistical analysis of biological soil properties

Soil Research ◽  
1991 ◽  
Vol 29 (1) ◽  
pp. 109 ◽  
Author(s):  
RGV Bramley ◽  
RE White
Keyword(s):  
Soil Properties ◽  
Spatial Variation ◽  
Sampling Design ◽  
High Variability ◽  
Geostatistical Analysis ◽  
Sample Variance ◽  
Geostatistical Methods ◽  
Sample Data ◽  
Principal Directions ◽  
The Relationship

An investigation of spatially dependent variability in the activity of soil nitrifiers indicated a number of shortcomings in the application of geostatistical methods to the analysis of spatial variation in biological soil properties which inherently have high variability. The relationship between the sill variance (Co+C) and sample variance (s2)), problems in the identification of anisotropic variation, and the effect of the scale of sampling on s2 are considered in relation to the sampling design used for collection of sample data. It is concluded that for minimum complication, sampling designs should be symmetrical in at least four principal directions, and that some sampling sites should be positioned at points between the nodes of the grid to ensure as wide a spread as possible in the distances between pairs of observations.

scholarly journals Modeling and Analysis on Teacher-Student Relationship

2019 ◽  
Vol 2019 ◽  
pp. 1-7
Author(s):  
Li Xu ◽  
Qi Yang
Keyword(s):  
Discrete Model ◽  
Equation Model ◽  
Reciprocal Relations ◽  
Modeling And Analysis ◽  
Teacher Student ◽  
Teacher Student Relationship ◽  
Sample Data ◽  
Teachers And Students ◽  
Student Relationship ◽  
The Relationship

Although the teacher-student relationship has been addressed in some studies, the cooperation or reciprocal relations between teachers and students have not been explored sufficiently. In this paper, a difference equation model is applied to express the relationship, stability analysis at the positive steady state of the discrete model is done to verify that the performance output is not empty, and hypothesis testing is conducted to show the validity of the model by means of sample data from a college. Then some reasonable suggestions are proposed to improve the performance output of teachers and students.

scholarly journals Characterization of tillage effects on the spatial variation of soil properties using ground-penetrating radar and electromagnetic induction

Geoderma ◽  
2013 ◽  
Vol 207-208 ◽  
pp. 310-322 ◽  
Author(s):  
François Jonard ◽  
Mohammad Mahmoudzadeh ◽  
Christian Roisin ◽  
Lutz Weihermüller ◽  
Frédéric André ◽  
...  
Keyword(s):  
Soil Properties ◽  
Spatial Variation ◽  
Ground Penetrating Radar ◽  
Electromagnetic Induction ◽  
Ground Penetrating

scholarly journals Soil Nutrient and Vegetation Diversity Patterns of Alpine Wetlands on the Qinghai-Tibetan Plateau

2021 ◽  
Vol 13 (11) ◽  
pp. 6221
Author(s):  
Muyuan Ma ◽  
Yaojun Zhu ◽  
Yuanyun Wei ◽  
Nana Zhao
Keyword(s):  
Species Diversity ◽  
Tibetan Plateau ◽  
Soil Properties ◽  
Soil Ph ◽  
Plant Biomass ◽  
Principal Component ◽  
Vegetation Diversity ◽  
Vegetation Biomass ◽  
Relative Contribution ◽  
The Relationship

To predict the consequences of environmental change on the biodiversity of alpine wetlands, it is necessary to understand the relationship between soil properties and vegetation biodiversity. In this study, we investigated spatial patterns of aboveground vegetation biomass, cover, species diversity, and their relationships with soil properties in the alpine wetlands of the Gannan Tibetan Autonomous Prefecture of on the Qinghai-Tibetan Plateau, China. Furthermore, the relative contribution of soil properties to vegetation biomass, cover, and species diversity were compared using principal component analysis and multiple regression analysis. Generally, the relationship between plant biomass, coverage, diversity, and soil nutrients was linear or unimodal. Soil pH, bulk density and organic carbon were also significantly correlated to plant diversity. The soil attributes differed in their relative contribution to changes in plant productivity and diversity. pH had the highest contribution to vegetation biomass and species richness, while total nitrogen was the highest contributor to vegetation cover and nitrogen–phosphorus ratio (N:P) was the highest contributor to diversity. Both vegetation productivity and diversity were closely related to soil properties, and soil pH and the N:P ratio play particularly important roles in wetland vegetation biomass, cover, and diversity.

Respiratory Periodicity and Electroencephalogram Arousals During Sleep in Older Adults

2007 ◽  
Vol 8 (4) ◽  
pp. 249-260 ◽  
Author(s):  
Barbara Waag Carlson ◽  
Virginia J. Neelon ◽  
John R. Carlson ◽  
Marilyn Hartman ◽  
Sunil Dogra
Keyword(s):  
Older Adults ◽  
Exploratory Study ◽  
High Variability ◽  
Arterial Oxygenation ◽  
Type B ◽  
Breathing Patterns ◽  
The Mean ◽  
Relationship Of ◽  
The Relationship ◽  
Electroencephalogram Eeg

The aim of this exploratory study was to examine the relationship of electroencephalogram (EEG) arousals to breathing patterns and the relationship of both arousals and breathing patterns to arterial oxygenation during sleep in older adults. Five older adults were monitored using standard polysomnography. Records were divided into 5-min segments and breathing patterns identified based on the level of respiratory periodicity and the variability in the frequency of breathing cycles. Standard criteria were used to determine sleep states and occurrence of EEG arousals. High respiratory periodicity was seen in 23% of the segments, whereas 24% had low respiratory periodicity with minimal variability in the frequency of breathing (Type A low respiratory periodicity) and 53% had low respiratory periodicity with high variability in the frequency of breathing (Type B low respiratory periodicity). Nearly all (97%) segments with high respiratory periodicity had EEG arousals, whereas fewer segments (33%) with low respiratory periodicity had arousals, regardless of the stage of sleep. Desaturations occurred more often in segments with high respiratory periodicity, F (2,4) = 57.3, p < .001, but overall, the mean SaO2 of segments with high respiratory periodicity did not differ from levels seen in segments with low respiratory periodicity, F( 2,4) = 0.77, ns. Our findings suggest that high respiratory periodicity is a common feature of EEG arousals and, in older adults, may be important for maintaining oxygen levels during desaturations during sleep.

scholarly journals Geostatistical prediction of clay percentage based on soil survey data

2002 ◽  
Vol 11 (4) ◽  
pp. 381-390
Author(s):  
A. TALKKARI ◽  
L. JAUHIAINEN ◽  
M. YLI-HALLA
Keyword(s):  
Soil Properties ◽  
Spatial Variation ◽  
Survey Data ◽  
Clay Content ◽  
Spherical Model ◽  
Simulation Method ◽  
Soil Survey ◽  
Management Zones ◽  
Additional Information ◽  
Clay Percentage

In precision farming fields may be divided into management zones according to the spatial variation in soil properties. Clay content is an important soil characteristic, because it is associated with other soil properties that are important in management. Soil survey data from 150 sampling sites taken from an area of 218 ha were used to predict the spatial variation of clay percentage geostatistically in an agricultural soil in Jokioinen, Finland. The exponential and spherical models with a nugget component were fitted to the experimental variogram. This indicated that the medium-range pattern could be modelled, but the short-range variation could not, due to sparsity of sample points at short distances. The effect of sampling density on the kriging error was evaluated using the random simulation method. Kriging with a spherical model produced a map with smooth variation in clay percentage. The standard error of kriging estimates decreased only slightly when the density of samples was increased. The predictions were divided into three classes based on the clay percentage. Areas with clay content below 30%, between 30% and 60% and over 60% belong to non-clay, clay and heavy clay zones, respectively. With additional information from the soil samples on the contents of nutrients and organic matter these areas can serve as agricultural management zones.;

scholarly journals KEMAMPUAN AUDIT TENURE MEMODERASI PENGARUH PENGALAMAN DAN SKEPTISISME AUDITOR DENGAN KUALITAS AUDIT

2017 ◽  
Vol 2 (1) ◽  
Author(s):  
I Gusti Ayu Nyoman Budiasih ◽  
Ketut Budiartha
Keyword(s):  
Data Analysis ◽  
Audit Quality ◽  
Total Sample ◽  
Financial Reports ◽  
Auditor Quality ◽  
Sample Data ◽  
Client Pressure ◽  
Relationship Of ◽  
The Relationship

ABSTRAKPentingnya laporan keuangan bagi banyak pihak, menyebabkan laporan tersebut harus disajikan secara relevan dan reliabel. Kualitas audit yang baik dapat menyebabkan laporan keuangan semakin dipercaya keasliannya. Kualitas audit tergantung pada independensi dan kompetensi auditor. Independensi dan kompetensi seorang auditor tergantung pada pengalaman maupun sikap skeptis yang dimiliki auditor tersebut. Pengalaman auditor akan meningkat dikarenakan telah terbiasa dengan pekerjaannya sehingga auditor akan bekerja secara efisien dan lebih tahan terhadap tekanan klien. Sampel yang dipilih menggunakan teknik sampel jenuh dengan jumlah sampel sebanyak 85 auditor. Pengumpulan data dilakukan dengan menyebarkan kuesioner kepada auditor yang menjadi sampel penelitian. Teknik analisis datanya menggunakan analisis regresi tanpa dan dengan variabel moderasi. Berdasarkan hasil analisis data dan pembahasan yang telah dilakukan, maka dapat disimpulkan bahwa kualitas audit di KAP Provinsi Bali memiliki hubungan secara positif dengan pengalaman dan skeptisisme auditor, audit tenure tidak mampu memoderasi hubungan pengalaman auditor dengan kualitas audit auditor di KAP Provinsi Bali, dan audit tenure mampu memoderasi hubungan skeptisisme auditor dengan kualitas audit auditor di KAP Provinsi Bali.Kata Kunci: audit tenure, pengalaman , skeptisisme auditor, kualitas audit  ABSTRACTThe importance of financial statements for many, causing the report to be presented in a relevant and reliable manner. A good audit quality can lead to more authentic financial reports. The quality of the audit depends on the independence and competence of the auditor. The independence and competence of an auditor depends on the experience and skepticism of the auditor. The experience of the auditor will increase due to the familiarity with the work so that the auditor will work efficiently and more resistant to client pressure. The samples were selected using a sample saturated technique with a total sample of 85 auditors. Data collection was done by distributing questionnaires to the auditor who became the research sample. Data analysis techniques use regression analysis without and with moderation variables. Based on the results of data analysis and discussion that have been done, it can be concluded that the audit quality in KAP Bali Province has a positive relationship with the experience and skepticism of auditors, audit tenure unable to moderate the relationship of auditor experience with audit auditor quality in KAP Bali Province and audit tenure able to moderate the relationship of auditor skepticism with audit auditor quality in KAP Bali Province.Keywords: audit tenure, experience, auditor skepticism, audit quality 

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