scholarly journals Quantifying the woody component of savanna vegetation along a density gradient in the Kalahari Bushveld: a comparison of two adapted point-centered quarter methods

2014 ◽  
Vol 36 (1) ◽  
pp. 91 ◽  
Author(s):  
Niels Dreber ◽  
Christiaan J. Harmse ◽  
Albie Götze ◽  
Winston S. W. Trollope ◽  
Klaus Kellner
Keyword(s):  
Assessment Methods ◽  
Point Of View ◽  
Sampling Effort ◽  
Frequency Distributions ◽  
Savanna Vegetation ◽  
Reliable Assessment ◽  
Distance Methods ◽  
Data Assessment ◽  
Under Sampling ◽  
Savanna Communities

Bush encroachment is a serious problem in savanna rangelands of southern Africa. There is a strong interest in practical and reliable assessment methods to quantify related vegetation changes in the woody layer such as the widely applied point-centred quarter (PCQ) methods. Several variations of these distance methods exist but their results differ due to differences in sampling effort and methodological accuracy. The aim of this study was to compare the performance of two recently developed adapted PCQ methods. These methods were used to estimate density, productivity and diversity of the woody layer of a semiarid savanna along a degradation gradient in the Kalahari rangelands. It was found that both adapted PCQ methods (APCQ10 and APCQ20, with the APCQ20 method using less recording points but a larger sampling area and higher sampling intensity per recording point) provided similar results for density, phytomass, available browse and browsing capacity in open, dense and encroached savanna types. Significant differences between the methods were obtained in differentiating height classes, which were, however, largely restricted to the woody layer above 2 m in open savanna types. There, applying the APCQ20 method avoided an under-sampling of larger shrubs and trees and increased precision in data assessment. This was confirmed by a better representation of species frequency distributions, as well as the density, phytomass and diversity status of the woody layer. These differences disappeared as the woody vegetation became denser with the APCQ10 method providing similar results to that of the APCQ20 method in densely vegetated and encroached savanna types. From a practical point of view, the APCQ10 method has a range of advantages in dense vegetation, where restricted movement impedes effective data collection. It is concluded that the APCQ20 method should be used to quantify open savanna communities, whereas the APCQ10 method is more suitable in dense stands of >1200 tree equivalents ha–1. Overall, the two APCQ methods were effective for assessing and monitoring woody savanna layers for management purposes but, for research, their accuracy still needs to be investigated in comparison to other assessment methods.

scholarly journals Species frequency distribution as a function of the surface area

2014 ◽  
Vol 53 (1) ◽  
pp. 87-98
Author(s):  
Anna J. Kwiatkowska
Keyword(s):  
Statistical Analysis ◽  
Surface Area ◽  
Frequency Distribution ◽  
Point Of View ◽  
Sample Plot ◽  
Statistical Point ◽  
Frequency Distributions ◽  
Species Frequency

Paper deals with the results of statistical analysis of the type of frequency distribution of species occuring in the field layers of two forest phytocoenoses. In the both cases frequency distributions were ranged out for the surface area of 1, 2, 4, 8, 16, 32 and 64 m<sup>2</sup>. The types of frequency distributions were determined on the grounds of the values of Fisher's and Pearson's K coefficients. Analysed distributions were classified into Pearson's system. Also the size of the sample plot at which the empirical frequency distributions were symetrical, from the statistical point of view, nad where they were U-shaped was determined.

scholarly journals Tüketicilerin Sosyo-ekonomik Nitelikleri ile Çevre Bilinci Düzeyleri Arasındaki İlişki ve Çevre Dostu Gıda Ürünlerini Satın Almalarında etkili olan Faktörler

2021 ◽  
Vol 9 (7) ◽  
pp. 1297-1303
Author(s):  
Yusuf Çakmakçı ◽  
Harun Hurma
Keyword(s):  
Environmentally Friendly ◽  
Food Products ◽  
Point Of View ◽  
Legal Regulations ◽  
Chi Square ◽  
Environmental Friendliness ◽  
Frequency Distributions ◽  
Factors Affecting ◽  
Label Information ◽  
Data Frequency

This study examined whether there is a relationship between the socio-economic and demographic characteristics of consumers while purchasing food products and the level of environmental awareness and environmental consciousness. In addition, the factors affecting consumers' trust in environmentally friendly food products were examined. The data of the study were obtained from the questionnaires made with 171 people in the district of Süleymanpaşa in Tekirdağ. In the evaluation of the obtained data, frequency distributions, chi-square, and factor analyses were used. In the results of the research, it determined that the level of environmental friendliness of consumers in their general consumption habits differs according to their age, education, having children under the age of 10, monthly income level, monthly food expenditure level. Consumers over the age of 36 were found to be more environmentally sensitive than other consumers. Similarly, consumers with undergraduate and higher education were found to be more environmentally friendly than those who have under undergraduate education. On the other hand, factor analysis was applied to 11 variables that affect the confidence level of consumers for food products produced with environmentally friendly and human health sensitive production methods. 11 variables were grouped under 3 factors as “Legal regulations and promotion efforts”, “Certificates and label information” and “Product awareness”. When evaluated from this point of view, it revealed that certificates and label information are very important as well as legal regulations in increasing the reliability of environmentally friendly food products in the eyes of consumers. However, it is understood that the environmental attitudes of consumers should also be taken into account in consumer-oriented studies in the food products market today.

scholarly journals Methods for Assessing the Investment Attractiveness of Innovative Projects

2021 ◽  
Vol 39 (6) ◽  
Author(s):  
Petro Pererva ◽  
Maksym Usov ◽  
Svitlana Chernobrovkina ◽  
Ludmila Larka ◽  
Viktor Rudyka
Keyword(s):  
Investment Strategy ◽  
Point Of View ◽  
Management Decision ◽  
Investment Climate ◽  
Key Factors ◽  
Logical Sequence ◽  
Reliable Assessment ◽  
Essential Components ◽  
Integral Assessment ◽  
Enterprise Investment

The material examines basic concepts of enterprise investment activities assessing from the point of view of the investment climate in the industry. The main objective of this study is to determine an integral assessment of the possibilities of financing innovative projects of industrial enterprises.The relevance of such a study is explained by the urgent need to form a more accurate and reliable assessment of the priorities of modern financing of innovative projects. The study takes into account additional factors that are applicable in the specific context of the enterprise.In the course of the study, the following logical sequence is observed: several relatively simple and essential components in the structure of enterprises are distinguished, which consistently have the most significant impact on the dynamics of changes in the innovative and investment characteristics of the entire industry as a whole. The research object is various energy enterprises of Ukraine since they are one of the key factors that allow creating and developing a competitive world economy in terms of energy-saving innovations, including non-traditional renewable energy.Based on the results obtained, it becomes possible to determine the integral indicators of the investment attractiveness of specific innovative projects. This technique allows you to sensibly assess all sides of the issue and make an informed management decision on forming the company’s investment strategy.

Effiziente Erfassung der Kronendichte mit Hilfe fotografischer Senkrechtaufnahmen | Efficient data assessment of canopy density with the help of vertical photographic exposures

2005 ◽  
Vol 156 (2) ◽  
pp. 59-64 ◽  
Author(s):  
Thomas Coch ◽  
René Bertiller ◽  
Beat Trachsler
Keyword(s):  
Objective Assessment ◽  
Visual Assessment ◽  
Ecological Assessment ◽  
Point Of View ◽  
Automatic Evaluation ◽  
Nature Protection ◽  
Canopy Density ◽  
Forest Reserves ◽  
Data Assessment ◽  
Efficient Data

From the point of view of silvicultural and nature protection the canopies of forests represent an important characteristic value. However, conventional forestry methods do not allow for a differentiated ecological assessment of the changed situation of radiation following light tending interventions. The method presented here enables the collection of exact and reproducible values on the actual density of the canopy from the ground, which calls for no specialist demands on workers or equipment. The paper describes the technology of vertical exposures for both analogue and digital photographic technology. In addition, we present a specially developed programme,which allows the automatic evaluation of the digital canopy exposures. We give two examples for areas of application of the method (finely structured map of trees along a water course and documentation of forestry intervention for the resumption of traditional middle forest management). The presented methodology enables an objective assessment of measures to manage the conditions of light in forests (e.g., special forest reserves), which is significantly superior to a visual assessment with regard to accuracy and reproducibility.

Mutualistic Networks in Time and Space

2013 ◽  
Author(s):  
Jordi Bascompte ◽  
Pedro Jordano
Keyword(s):  
Theoretical Models ◽  
Theoretical Work ◽  
Point Of View ◽  
Sampling Effort ◽  
Time And Space ◽  
Species Accumulation Curves ◽  
High Turnover ◽  
Accumulation Curves ◽  
Mutualistic Networks ◽  
Temporal Dimensions

This chapter reviews the combination of empirical and theoretical work describing the dynamics of mutualistic networks in time and space. It also addresses what components of these networks are time and space invariant. On a daily basis, network assembly is intermediate between preferential and random attachment. In a year-to-year scale, there is a very high turnover in species and interactions across years, and yet the global structure of the network is quite constant. Across space, theoretical models predict that plantanimal interactions increase spatial heterogeneity. The spatial and temporal dimensions are also interesting from a more methodological point of view to assess the effect of sampling effort. Interaction accumulation curves are the equivalent of species accumulation curves used in biodiversity monitoring and can be used to assess the role of sampling effort. But important natural history details explain a fraction of the nonobserved links. Therefore, treating missing interactions as the expected unique result of sampling bias would miss important components of the ecological and (co)evolutionary basis of mutualistic networks.

Activity patterns in sympatric carnivores in the Nahuelbuta Mountain Range, southern-central Chile

Mammalia ◽  
2017 ◽  
Vol 81 (5) ◽  
Author(s):  
Alfredo H. Zúñiga ◽  
Jaime E. Jiménez ◽  
Pablo Ramírez de Arellano
Keyword(s):  
Species Interactions ◽  
Activity Patterns ◽  
Point Of View ◽  
Camera Traps ◽  
Sampling Effort ◽  
Mountain Range ◽  
Central Chile ◽  
Biological Communities ◽  
Southern Central ◽  
Sympatric Carnivores

AbstractSpecies interactions determine the structure of biological communities. In particular, interference behavior is critical as dominant species can displace subordinate species depending on local ecological conditions. In carnivores, the outcome of interference may have important consequences from the point of view of conservation, especially when vulnerable species are the ones suffering displacement. Using 24 baited camera traps and a sampling effort of 2821 trap nights, we examined the activity patterns and spatial overlap of an assemblage of five sympatric carnivores in the Nahuelbuta Mountain Range, in southern-central Chile. In this forested landscape we found predominantly nocturnal activity in all species, but not for the puma (

Exploring valid and reliable assessment methods for care management education

2016 ◽  
Vol 29 (3) ◽  
pp. 240-250 ◽  
Author(s):  
Lokke Gennissen ◽  
Lorette Stammen ◽  
Jolien Bueno-de-Mesquita ◽  
Sietse Wieringa ◽  
Jamiu Busari
Keyword(s):  
Care Management ◽  
Leadership Competencies ◽  
Assessment Method ◽  
Assessment Methods ◽  
Delphi Survey ◽  
Content Type ◽  
Residency Programs ◽  
Clinical Educators ◽  
Reliable Assessment ◽  
Medical Leadership

Purpose It is assumed that the use of valid and reliable assessment methods can facilitate the development of medical residents’ management and leadership competencies. To justify this assertion, the perceptions of an expert panel of health care leaders were explored on assessment methods used for evaluating care management (CM) development in Dutch residency programs. This paper aims to investigate how assessors and trainees value these methods and examine for any inherent benefits or shortcomings when they are applied in practice. Design/methodology/approach A Delphi survey was conducted among members of the platform for medical leadership in The Netherlands. This panel of experts was made up of clinical educators, practitioners and residents interested in CM education. Findings Of the respondents, 40 (55.6 per cent) and 31 (43 per cent) participated in the first and second rounds of the Delphi survey, respectively. The respondents agreed that assessment methods currently being used to measure residents’ CM competencies were weak, though feasible for use in many residency programs. Multi-source feedback (MSF, 92.1 per cent), portfolio/e-portfolio (86.8 per cent) and knowledge testing (76.3 per cent) were identified as the most commonly known assessment methods with familiarity rates exceeding 75 per cent. Practical implications The findings suggested that an “assessment framework” comprising MSF, portfolios, individual process improvement projects or self-reflections and observations in clinical practice should be used to measure CM competencies in residents. Originality/value This study reaffirms the need for objective methods to assess CM skills in post-graduate medical education, as there was not a single assessment method that stood out as the best instrument.

A Numerical-Experimental Approach of Indentation Problem: Part I — Force-Dent Response of Steel Pipes

2017 ◽  
Author(s):  
Mario A. Polanco-Loria ◽  
Håvar Ilstad ◽  
Erik Levold
Keyword(s):  
Experimental Approach ◽  
Technology Development ◽  
Experimental Tests ◽  
Assessment Methods ◽  
Development Plan ◽  
Close Collaboration ◽  
Steel Pipes ◽  
Environmental Consequences ◽  
Reliable Assessment ◽  
Indentation Problem

Accidents by trawling impact have the potential of environmental consequences, in terms of safety, monetary values and reputation. Aware of this situation a technology development plan on “Pipeline subject to high interference loads” has been established at STATOIL in close collaboration with GASSCO. The overall achievement is to adapt and introduce more reliable assessment methods in the load and response of pipelines under a trawling impact scenario. This work includes a review of some known force-indentation models appeared in the literature. Some comments on the recently updated version of the DNV-RP-F111 document. Next, the description of the numerical results of 12 analyses of steel pipes studied is described and based on these results a new force-dent proposal is presented. The proposed equations are validated against experimental tests and the findings indicated fairly good predictions as indicated in the conclusions.

scholarly journals Towards Compilation of Balanced Protein Stability Datasets: Flattening the ΔΔG Curve through Systematic Under-sampling

2021 ◽  
Author(s):  
Narod Kebabci ◽  
Ahmet Can Timucin ◽  
Emel Timucin
Keyword(s):  
Protein Stability ◽  
Binary Classification ◽  
Structural Features ◽  
Frequency Distributions ◽  
Error Analyses ◽  
Under Sampling ◽  
Neutral Mutations ◽  
The Impact

AbstractProtein stability datasets contain neutral mutations that are highly concentrated in a much narrower ΔΔG range than destabilizing and stabilizing mutations. Notwith-standing their high density, often studies analyzing stability datasets and/or predictors ignore the neutral mutations and use a binary classification scheme labeling only destabilizing and stabilizing mutations. Recognizing that highly concentrated neutral mutations would affect the quality of stability datasets, we have explored three protein stability datasets; S2648, PON-tstab and the symmetric Ssym that differ in size and quality. A characteristic leptokurtic shape in the ΔΔG distributions of all three datasets including the curated and symmetric ones were reported due to concentrated neutral mutations. To further investigate the impact of neutral mutations on ΔΔG predictions, we have comprehensively assessed the performance of eleven predictors on the PON-tstab dataset. Correlation and error analyses showed that all of the predictors performed the best on the neutral mutations while their performance became gradually worse as the ΔΔG of the mutations departed further from the neutral zone regardless of the direction, implying a bias towards dense mutations. To this end, after unraveling the role of concentrated neutral mutations in biases of stability datasets, we described a systematic under-sampling approach to balance the ΔΔG distributions. Before under-sampling, mutations were clustered based on their biochemical and/or structural features and then three mutations were systematically selected from every 2 kcal/mol of each cluster. Upon implementation of this approach by distinct clustering schemes, we generated five subsets varying in size and ΔΔG distributions. All subsets notably showed amelioration of not only the shape of ΔΔG distributions but also other pre-existing imbalances in the frequency distributions. We also reported differences in the performance of the predictors between the parent and under-sampled subsets due to the enrichment of previously under-represented mutations in the subsets. Altogether, this study not only elaborated the pivotal role of concentrated mutations in the dataset biases but also contemplated and realized a rational strategy to tackle this and other forms of biases. Under-sampling code is available on GitHub (https://github.com/narodkebabci/gRoR).

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