scholarly journals Evaluation of Aluminum Resistance among Zoysia Willd. Accessions from China

HortScience ◽  
2017 ◽  
Vol 52 (2) ◽  
pp. 225-229
Author(s):  
Chun-qiong Huang ◽  
Guo-dao Liu ◽  
Chang-jun Bai
Keyword(s):  
Cluster Analysis ◽  
Soil Conservation ◽  
Liquid Culture ◽  
Acid Soils ◽  
Plant Production ◽  
Small Scale ◽  
The Mean ◽  
Subordinate Function ◽  
Moderately Resistant ◽  
Nutrient Solutions

Aluminum ion (Al3+) toxicity is a major factor limiting plant production on acid soils. Species of zoysiagrass (Zoysia Willd.) are grown for lawn, turf, and soil conservation, especially in temperate zones. Herein, 46 zoysiagrass accessions obtained from eight provinces in China were evaluated for Al resistance using small-scale liquid culture. Each accession was grown in triplicate in nutrient solutions with 1500 μm AlCl3·6H2O (experimental) or without exposure to Al (control). The mean dry weights of the roots, shoots, and total bodies of the accessions relative to those of the nontreated controls were calculated after 60 days, and showed considerable diversity. Overall, the cv for the shoot, root, and total weights of the Al-treated accessions relative to the nontreated controls were 45.78%, 56.67%, and 42.84%, respectively. A cluster analysis based on Al resistance and subordinate function values revealed that 12 of the 46 zoysiagrass accessions (26.09%) were resistant to Al, 9 (19.57%) were moderately resistant, and 25 (54.35%) were sensitive to Al stress. These 46 zoysiagrass accessions from China have great potential for horticultural breeding and development, and for research into mechanisms that underlie Al resistance.

Quantification of small-scale heterogeneity in aquatic aminopeptidase activity

2020 ◽  
Vol 84 ◽  
pp. 127-140
Author(s):  
BM Gaas ◽  
JW Ammerman
Keyword(s):  
Chlorophyll Fluorescence ◽  
Leucine Aminopeptidase ◽  
Hudson River ◽  
Aminopeptidase Activity ◽  
Small Scale ◽  
Analysis Instrument ◽  
Sequential Samples ◽  
Degree Of Confidence ◽  
The Mean ◽  
Hydrolysis Of

Leucine aminopeptidase (LAP) is one of the enzymes involved in the hydrolysis of peptides, and is sometimes used to indicate potential nitrogen limitation in microbes. Small-scale variability has the potential to confound interpretation of underlying patterns in LAP activity in time or space. An automated flow-injection analysis instrument was used to address the small-scale variability of LAP activity within contiguous regions of the Hudson River plume (New Jersey, USA). LAP activity had a coefficient of variation (CV) of ca. 0.5 with occasional values above 1.0. The mean CVs for other biological parameters—chlorophyll fluorescence and nitrate concentration—were similar, and were much lower for salinity. LAP activity changed by an average of 35 nmol l-1 h-1 at different salinities, and variations in LAP activity were higher crossing region boundaries than within a region. Differences in LAP activity were ±100 nmol l-1 h-1 between sequential samples spaced <10 m apart. Variogram analysis indicated an inherent spatial variability of 52 nmol l-1 h-1 throughout the study area. Large changes in LAP activity were often associated with small changes in salinity and chlorophyll fluorescence, and were sensitive to the sampling frequency. This study concludes that LAP measurements in a sample could realistically be expected to range from zero to twice the average, and changes between areas or times should be at least 2-fold to have some degree of confidence that apparent patterns (or lack thereof) in activity are real.

Small-Scale Cultural Tourism Events: Residents' Perceptions on Their Quality and Impacts

2020 ◽  
Vol 25 (2) ◽  
pp. 283-293
Author(s):  
Maria Doumi ◽  
Anna Kyriakaki ◽  
Theodoros Stavrinoudis
Keyword(s):  
Cluster Analysis ◽  
Present Article ◽  
Natural Environment ◽  
Local Level ◽  
Tourism Development ◽  
Cultural Tourism ◽  
Small Scale ◽  
Primary Research ◽  
Local Society ◽  
Cultural Events

In the present article researchers feature the examination of the opinions and attitudes of the residents of Chios island in Greece. It is based on the investigation of both the characteristics (quality, potential, organization) of the island's main annual cultural events (Rocket War, Agas, and Mostra) and their possible impact on the local society, economy, tourism, and natural environment. Cluster analysis was used to classify the residents under three groups: Embracers, Realists, Neutrals. Each group has particular characteristics and a clearly defined opinion about local cultural tourism events and their impact on a local level. According to the main findings of the primary research some particularly interesting aspects of the effects of local cultural tourism events both on the local level and on the island's tourism development emerge. The conclusions drawn from the elaboration of such findings afford an opportunity to understand better the general impact of cultural events and by the same token to assist government bodies, residents, and other stakeholders in maximizing benefits, whenever possible.

scholarly journals Quantification of Measurement and Model Effects in Monopile Foundation Scour Protection Experiments

2021 ◽  
Vol 9 (6) ◽  
pp. 585
Author(s):  
Minghao Wu ◽  
Leen De Vos ◽  
Carlos Emilio Arboleda Chavez ◽  
Vasiliki Stratigaki ◽  
Maximilian Streicher ◽  
...  
Keyword(s):  
Standard Deviation ◽  
Flow Field ◽  
Three Dimensional ◽  
Small Scale ◽  
Maximum Wave Height ◽  
Chaotic Flow ◽  
The Mean ◽  
Scour Protection ◽  
Damage Number ◽  
Measurement Effects

The present work introduces an analysis of the measurement and model effects that exist in monopile scour protection experiments with repeated small scale tests. The damage erosion is calculated using the three dimensional global damage number S3D and subarea damage number S3D,i. Results show that the standard deviation of the global damage number σ(S3D)=0.257 and is approximately 20% of the mean S3D, and the standard deviation of the subarea damage number σ(S3D,i)=0.42 which can be up to 33% of the mean S3D. The irreproducible maximum wave height, chaotic flow field and non-repeatable armour layer construction are regarded as the main reasons for the occurrence of strong model effects. The measurement effects are limited to σ(S3D)=0.039 and σ(S3D,i)=0.083, which are minor compared to the model effects.

Use of information and communication technologies in small-scale dairy production systems in central Mexico

2020 ◽  
Vol 56 (5) ◽  
pp. 767-779
Author(s):  
Juan de Dios García-Villegas ◽  
Anastacio García-Martínez ◽  
Carlos Manuel Arriaga-Jordán ◽  
Monica Elizama Ruiz-Torres ◽  
Adolfo Armando Rayas-Amor ◽  
...  
Keyword(s):  
Cluster Analysis ◽  
Production Systems ◽  
Communication Technologies ◽  
Small Scale ◽  
Central Mexico ◽  
Dairy Production ◽  
Dairy Farmers ◽  
Use Of Technology ◽  
Group 2 ◽  
Small Scale Dairy

AbstractThe objective of the study was to characterize small-scale dairy production systems to identify the technological preferences according to the farmer and farm characteristics and to analyze the importance and role of the information communication technologies (ICTs) in the dissemination of information related to management and livestock activities. To collect the data, a survey was applied to 170 small-scale dairy farmers from central Mexico. To characterize the farms, a factor analysis (FA) and cluster analysis (CA) were performed. To compare and identify differences between groups, a Kruskal–Wallis test was conducted. Four factors that explain 70.93% of the accumulated variance were identified; these factors explain the use of technology, production characteristics, social connections, and use of ICTs. The cluster analysis identified four groups. Group 1 was integrated by farmers with more experience and the largest farms. Group 2 had higher studies and use of ICTs. Group 3 was formed by young farmers but had a low use of technology. Group 4 contained older farmers with a low use of technology. The young farmers with higher studies have begun to incorporate ICTs into their daily activities on the farm, as observed in Group 2. Smartphones were the most used and were considered important by the farmers of the four groups, since they enable interaction with other farmers and the dissemination of topics of interest related with the farm. In conclusion, four group of farmers were differentiated; therefore, different extension approaches should be implemented to take into account the preferences and the technologies considered most important for each group. The ICTs are emerging technologies among small-scale dairy farmers to communicate information related to livestock management, mainly by young farmers with studies of secondary, as observed in Group 2.

scholarly journals Methodology for Developing Hydrological Models Based on an Artificial Neural Network to Establish an Early Warning System in Small Catchments

2016 ◽  
Vol 2016 ◽  
pp. 1-14 ◽  
Author(s):  
Ivana Sušanj ◽  
Nevenka Ožanić ◽  
Ivan Marović
Keyword(s):  
Neural Network ◽  
Artificial Neural Network ◽  
Early Warning ◽  
Early Warning System ◽  
Warning System ◽  
Small Scale ◽  
Ann Model ◽  
Data Value ◽  
The Mean ◽  
Artificial Neural

In some situations, there is no possibility of hazard mitigation, especially if the hazard is induced by water. Thus, it is important to prevent consequences via an early warning system (EWS) to announce the possible occurrence of a hazard. The aim and objective of this paper are to investigate the possibility of implementing an EWS in a small-scale catchment and to develop a methodology for developing a hydrological prediction model based on an artificial neural network (ANN) as an essential part of the EWS. The methodology is implemented in the case study of the Slani Potok catchment, which is historically recognized as a hazard-prone area, by establishing continuous monitoring of meteorological and hydrological parameters to collect data for the training, validation, and evaluation of the prediction capabilities of the ANN model. The model is validated and evaluated by visual and common calculation approaches and a new evaluation for the assessment. This new evaluation is proposed based on the separation of the observed data into classes based on the mean data value and the percentages of classes above or below the mean data value as well as on the performance of the mean absolute error.

scholarly journals Statistical analysis in support of maintaining a healthy traditional Siamese cat population

2021 ◽  
Vol 53 (1) ◽  
Author(s):  
Arthur M. A. Pistorius ◽  
Ineke Blokker
Keyword(s):  
Genetic Diversity ◽  
Cluster Analysis ◽  
Companion Animals ◽  
Hereditary Diseases ◽  
Small Scale ◽  
Genetic Traits ◽  
Inbreeding Coefficients ◽  
A Value ◽  
Siamese Cat ◽  
Line Breeding

Abstract Background For many years, breeders of companion animals have applied inbreeding or line breeding to transfer desirable genetic traits from parents to their offspring. Simultaneously, this resulted in a considerable spread of hereditary diseases and phenomena associated with inbreeding depression. Results Our cluster analysis of kinship and inbreeding coefficients suggests that the Thai or traditional Siamese cat could be considered as a subpopulation of the Siamese cat, which shares common ancestors, although they are considered as separate breeds. In addition, model-based cluster analysis could detect regional differences between Thai subpopulations. We show that by applying optimal contribution selection and simultaneously limiting the contributions by other breeds, the genetic diversity within subpopulations can be improved. Conclusion In principle, the European mainland Thai cat population can achieve a genetic diversity of about 26 founder genome equivalents, a value that could potentially sustain a genetically diverse population. However, reaching such a target will be difficult in the absence of a supervised breeding program. Suboptimal solutions can be obtained by minimisation of kinships within regional subpopulations. Exchanging animals between different regions on a small scale might be already quite useful to reduce the kinship, by achieving a potential diversity of 23 founder genome equivalents. However, contributions by other breeds should be minimised to preserve the original Siamese gene pool.

Extraction Techniques and Analysis of Turbulence Quantities From In-Cylinder Velocity Data

1989 ◽  
Vol 111 (3) ◽  
pp. 466-478 ◽  
Author(s):  
A. E. Catania ◽  
A. Mittica
Keyword(s):  
Direct Injection ◽  
Detailed Comparison ◽  
Ensemble Average ◽  
Small Scale ◽  
Velocity Data ◽  
Mean Flow ◽  
Reciprocating Engine ◽  
Reduction Methods ◽  
The Mean ◽  
Correlation And Spectral Analysis

In addition to the frequently used statistical ensemble-average, non-Reynolds filtering operators have long been proposed for nonstationary turbulent quantities. Several techniques for the reduction of velocity data acquired in the cylinder of internal combustion reciprocating engines have been developed by various researchers in order to separate the “mean flow” from the “fluctuating motion,” cycle by cycle, and to analyze small-scale engine turbulence by statistical methods. Therefore a thorough examination of these techniques and a detailed comparison between them would seem to be a preliminary step in attempting a general study of unconventional averaging procedures for reciprocating engine flow application. To that end, in the present work, five different cycle-resolved data reduction methods and the conventional ensemble-average were applied to the same in-cylinder velocity data, so as to review and compare them. One of the methods was developed by the authors. The data were acquired in the cylinder of a direct-injection automotive diesel engine, during induction and compression strokes, using an advanced hot-wire anemometry technique. Correlation and spectral analysis of the engine turbulence, as determined from the data with the different procedures, were also performed.

scholarly journals Energetic Submesoscales Maintain Strong Mixed Layer Stratification during an Autumn Storm

2017 ◽  
Vol 47 (10) ◽  
pp. 2419-2427 ◽  
Author(s):  
Daniel B. Whitt ◽  
John R. Taylor
Keyword(s):  
Mixed Layer ◽  
North Atlantic ◽  
Small Scale ◽  
Upper Ocean ◽  
Ocean Mixed Layer ◽  
Ocean Stratification ◽  
The North ◽  
Large Eddy ◽  
The Mean ◽  
Scale Turbulence

AbstractAtmospheric storms are an important driver of changes in upper-ocean stratification and small-scale (1–100 m) turbulence. Yet, the modifying effects of submesoscale (0.1–10 km) motions in the ocean mixed layer on stratification and small-scale turbulence during a storm are not well understood. Here, large-eddy simulations are used to study the coupled response of submesoscale and small-scale turbulence to the passage of an idealized autumn storm, with a wind stress representative of a storm observed in the North Atlantic above the Porcupine Abyssal Plain. Because of a relatively shallow mixed layer and a strong downfront wind, existing scaling theory predicts that submesoscales should be unable to restratify the mixed layer during the storm. In contrast, the simulations reveal a persistent and strong mean stratification in the mixed layer both during and after the storm. In addition, the mean dissipation rate remains elevated throughout the mixed layer during the storm, despite the strong mean stratification. These results are attributed to strong spatial variability in stratification and small-scale turbulence at the submesoscale and have important implications for sampling and modeling submesoscales and their effects on stratification and turbulence in the upper ocean.

scholarly journals Evaluating the influence of anxiety and depression on academic performance in high school students

2021 ◽  
Author(s):  
Waleed Ahmed Shahzad
Keyword(s):  
High School ◽  
Academic Performance ◽  
High School Students ◽  
Anxiety And Depression ◽  
Small Scale ◽  
School Students ◽  
Cross Sectional ◽  
Grade Point ◽  
Negative Effect ◽  
The Mean

The purpose of this study was to evaluate whether anxiety and depression have a negative effect on academic performance. This small-scale study assessed the relationship between these factors. A cross-sectional questionnaire survey was carried out. A randomized sample of 52 high school students based in various schools across Lahore participated in the survey. Of the participants, 32 were males and 20 were females. As a measure of anxiety and depression 14 questions from the DASS-21 were utilized (The 7 questions pertaining to the measure of stress were not included in this study). Based on the DASS-21 score obtained by the respondents they were classified under categories of normal, mild, moderate, severe and extremely severe levels of anxiety and depression. As a measure of academic performance, the Grade Point Average (GPA) of the students was obtained via the survey. The mean average GPA was calculated for all the students falling under the aforementioned categories pertaining to anxiety and depression separately and these averages were compared. It was found that the mean average GPA was highest in students falling under the categories of normal and mild levels of anxiety and depression. Whereas, mean average GPA was lower in students suffering from severe levels of anxiety and depression. These findings suggest the need to come up with methods to combat anxiety and depression in high school students as these factors impede academic performance.

scholarly journals Influence of spatial heterogeneity of local surface albedo on the area-averaged surface albedo retrieved from airborne irradiance measurements

2013 ◽  
Vol 6 (3) ◽  
pp. 527-537 ◽  
Author(s):  
E. Jäkel ◽  
M. Wendisch ◽  
B. Mayer
Keyword(s):  
Optical Depth ◽  
Surface Albedo ◽  
Radiative Transfer Model ◽  
Small Scale ◽  
Mean Deviation ◽  
Transfer Model ◽  
Horizontal Distance ◽  
Local Surface ◽  
Atmospheric Scattering ◽  
The Mean

Abstract. Spectral airborne upward and downward irradiance measurements are used to derive the area-averaged surface albedo. Real surfaces are not homogeneous in their reflectivity. Therefore, this work studies the effects of the heterogeneity of surface reflectivity on the area-averaged surface albedo to quantify how well aircraft measurements can resolve the small-scale variability of the local surface albedo. For that purpose spatially heterogeneous surface albedo maps were input into a 3-dimensional (3-D) Monte Carlo radiative transfer model to simulate 3-D irradiance fields. The calculated up- and downward irradiances in altitudes between 0.1 and 5 km are used to derive the area-averaged surface albedo using an iterative retrieval method that removes the effects due to atmospheric scattering and absorption within the layer beneath the considered level. For the case of adjacent land and sea surfaces, parametrizations are presented which quantify the horizontal distance from the coastline that is required to reduce surface heterogeneity effects on the area-averaged surface albedo to a given limit. The parametrization which is a function of altitude, aerosol optical depth, single scattering albedo, and the ratio of local land and sea albedo was applied for airborne spectral measurements. In addition, the deviation between area-averaged and local surface albedo is determined for more complex surface albedo maps. For moderate aerosol conditions (optical depth less than 0.4) and a wavelength range between 400 and 1000 nm, the altitude and the heterogeneity of the surface albedo are the dominant factors determining the mean deviation between local and area-averaged surface albedo. A parametrization of the mean deviation is applied to an albedo map that was derived from a Landsat image of an area in East Anglia (UK). Parametrization and direct comparison of local and area-averaged surface albedo show similar mean deviations (20% vs. 25%) over land.

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