scholarly journals Ecohydrological threats to Colophospermum mopane in southern Zimbabwe

2019 ◽  
Vol 11 (2) ◽  
Author(s):  
Tendayi Gondo ◽  
Agnes Musyoki ◽  
Aina T. Adeboyejo
Keyword(s):  
Management Practices ◽  
Life Support ◽  
Rural Households ◽  
Large Population ◽  
Principal Component ◽  
Agglomerative Clustering ◽  
Colophospermum Mopane ◽  
Hierarchical Agglomerative Clustering ◽  
Arid Landscapes ◽  
Semi Arid

Rapid ecohydrological changes in semi-arid landscapes are increasingly threatening humanity’s life-support systems and eroding many of the ecosystem services (ESs) upon which humans occupying such regions depend. Knowing which services and ecohydrological changes to be most concerned about is indispensable to maintaining the general health of such ecosystems and for developing effective ecosystem management practices. In the semi-arid regions of southwestern Zimbabwe where a large population of rural households depend on ESs extracted from the Colophospermum mopane tree, such understanding may be critical in reversing potential ES losses that may have catastrophic effects on the lives of many. We surveyed a total of 127 rural households who occupy the semi-arid landscapes of the Colophospermum mopane belt in southern Zimbabwe. We assessed the ecohydrological conditions characterising ecosystems where they obtain ES provisioning goods using a number of ecohydrological variables commonly cited in the literature on ecohydrology. Building on principal component analysis (PCA), we employed a hierarchical agglomerative clustering method to create unique clusters of households that depicted different levels of risks or threats associated with their ES provisioning harvesting practices. Multiple regression analysis was further performed to identify significant ecohydrological cluster-defining variables. Our results showed that spatial differences in ecohydrological parameters resulted in four distinct ES resource thresholds depicting four categories of risks that households face in extracting such resources in nearby landscapes. We concluded by proposing a number of landscape restoration or management practices targeted at reversing potential ES losses and subsequently safeguarding the livelihoods of many who depend on ESs.

scholarly journals Chromatographic, Chemometric and Antioxidant Assessment of the Equivalence of Granules and Herbal Materials of Angelicae Sinensis Radix

Medicines ◽  
2020 ◽  
Vol 7 (6) ◽  
pp. 35
Author(s):  
Valentina Razmovski-Naumovski ◽  
Xian Zhou ◽  
Ho Yee Wong ◽  
Antony Kam ◽  
Jarryd Pearson ◽  
...  
Keyword(s):  
Ferulic Acid ◽  
Caffeic Acid ◽  
Radical Scavenging ◽  
Principal Component ◽  
Ultra Performance Liquid Chromatography ◽  
Array Detector ◽  
Agglomerative Clustering ◽  
Antioxidant Power ◽  
Hierarchical Agglomerative Clustering ◽  
Angelicae Sinensis

Background: Granules are a popular way of administrating herbal decoctions. However, there are no standardised quality control methods for granules, with few studies comparing the granules to traditional herbal decoctions. This study developed a multi-analytical platform to compare the quality of granule products to herb/decoction pieces of Angelicae Sinensis Radix (Danggui). Methods: A validated ultra-performance liquid chromatography coupled with photodiode array detector (UPLC-PDA) method quantitatively compared the aqueous extracts. Hierarchical agglomerative clustering analysis (HCA) and principal component analysis (PCA) clustered the samples according to three chemical compounds: ferulic acid, caffeic acid and Z-ligustilide. Ferric ion-reducing antioxidant power (FRAP) and 2,2-Diphenyl-1-picrylhydrazyl radical scavenging capacity (DPPH) assessed the antioxidant activity of the samples. Results: HCA and PCA allocated the samples into two main groups: granule products and herb/decoction pieces. Greater differentiation between the samples was obtained with three chemical markers compared to using one marker. The herb/decoction pieces group showed comparatively higher extraction yields and significantly higher DPPH and FRAP (p < 0.05), which was positively correlated to caffeic acid and ferulic acid, respectively. Conclusions: The results confirm the need for the quality assessment of granule products using more than one chemical marker for widespread practitioner and consumer use.

scholarly journals Elemental quantification, chemistry, and source apportionment in golf course facilities in a semi-arid urban landscape using a portable X-ray fluorescence spectrometer

Solid Earth ◽  
2015 ◽  
Vol 6 (2) ◽  
pp. 415-424 ◽  
Author(s):  
T. K. Udeigwe ◽  
J. Young ◽  
T. Kandakji ◽  
D. C. Weindorf ◽  
M. A. Mahmoud ◽  
...  
Keyword(s):  
Source Apportionment ◽  
Management Practices ◽  
Principal Component ◽  
The United States ◽  
Golf Course ◽  
High Plains ◽  
Urban Landscapes ◽  
Anthropogenic Influences ◽  
X Ray ◽  
Semi Arid

Abstract. This study extends the application of the portable X-ray fluorescence (PXRF) spectrometry to the examination of elements in semi-arid urban landscapes of the Southern High Plains (SHP) of the United States, focusing on golf courses. The complex environmental challenges of this region and the unique management practices at golf course facilities could lead to differences in concentration and in the chemistry of elements between managed (irrigated) and non-managed (non-irrigated) portions of these facilities. Soil samples were collected at depths of 0–10, 10–20, and 20–30 cm from managed and non-managed areas of seven different facilities in the city of Lubbock, Texas, and analyzed for a suite of soil properties. Total elemental quantification was conducted using a PXRF spectrometer. Findings mostly indicated no significant differences in the concentration of examined elements between the managed and non-managed areas of the facilities. However, strong positive relationships (R = 0.82−0.91, p < 0.001) were observed among elements (e.g., Fe on the one hand and Cr, Mn, Ni, and As on the other; Cu and Zn; As and Cr) and between these elements and soil constituents or properties such as clay, calcium carbonate, organic matter, and pH. The strengths of these relationships were mostly higher in the non-managed areas, suggesting a possible alteration in the chemistry of these elements by anthropogenic influences in the managed areas. Principal component and correlation analyses within the managed areas suggested that As, Cr, Fe, Mn, and Ni could be of lithogenic origin, while Cu, Pb, and Zn could have anthropogenic influences. Only one possible, likely lithogenic, source of the elements was identified within the non-managed areas. As evidenced by the study, the PXRF spectrometer can be a valuable tool for elemental quantification and rapid investigation of elemental interaction and source apportionment in semi-arid climates.

A proposed winter-injury classification for apple trees on the northern fringe of commercial production

1992 ◽  
Vol 72 (2) ◽  
pp. 507-516 ◽  
Author(s):  
Warren K. Coleman
Keyword(s):  
Cluster Analysis ◽  
New Brunswick ◽  
Air Temperature ◽  
Hierarchical Classification ◽  
Principal Component ◽  
Fruit Production ◽  
Agglomerative Clustering ◽  
Apple Trees ◽  
Hierarchical Agglomerative Clustering ◽  
Temperature Records

Because of a severe and highly variable winter environment, commercially significant fruit production in New Brunswick is restricted to a few hardy apple cultivars. Cluster, principal-component and discriminant analyses were applied to monthly temperature records to derive a satisfactory classification of recorded occurrences of winter injury in New Brunswick during the 20th century. Production of a dendrogram based on a hierarchical, agglomerative clustering technique separated root- from shoot-injury years. The analyses suggested that low temperatures per se in December, January or February are not the dominant factors controlling recurring winter shoot injury of apple trees in New Brunswick. Rather mild weather during mid-winter (especially maximum air temperature in February) and the October mean air temperature during the fall hardening-off period consistently contributed to the hierarchical classification. Cluster analysis allowed the separation of recorded occurrences of winter injury into plausible groupings that should complement current attempts to understand the underlying causes of winter injury in New Brunswick.Key words: Malus × domestica, apple, winter injury, cluster analysis

scholarly journals Assessment by Multivariate Analysis of Groundwater between Low and High Tides Interactions in East Coast of Terengganu

2018 ◽  
Vol 7 (3.14) ◽  
pp. 80
Author(s):  
Hafizan Juahir ◽  
Muhammad Barzani Gasim ◽  
Mohd. Khairul Amri Kamarudin ◽  
Azman Azid ◽  
Norsyuhada Hairoma ◽  
...  
Keyword(s):  
High Tide ◽  
Principal Component ◽  
Agglomerative Clustering ◽  
Physico Chemical ◽  
Groundwater Samples ◽  
Positive Loading ◽  
Hierarchical Agglomerative Clustering ◽  
Compositional Pattern ◽  
Dry Seasons ◽  
The Difference

World sea level rise has an effect in the rise on high and low tides levels in coastal areas of Terengganu. Because of that, as many as 13 groundwater represented of well that located close to Terengganu coastline were sampled and analyzed. Samplings were conducted for the wet and dry seasons and also for the high and low tides at the same sampling wells to identify the variation of groundwater quality temporally. A Global Positioning System (GPS) was used to locate the exact coordinates of each sampling well. Nineteen physico-chemical parameters were analyzed from groundwater samples. Principal Component Analysis (PCA) was adopted to observe the contrast of the compositional pattern among the variables and to recognize the factors that influence the parameters as an input to define water intrusion. Hierarchical Agglomerative Clustering Analysis (HACA) is performed on data to group the sampling wells into a few clusters. The results show that from nineteen parameters only five has strong positive loading; EC (0.99), TDS (0.99), chloride (0.99), sulphate (0.92) and salinity (0.99) during high and low tides. The difference are BOD and DO have strong positive loading during low tide while turbidity and TSS were strong positive loading during high tide.  

scholarly journals Elemental quantification, chemistry, and source apportionment in golf course facilities in semi-arid urban landscape using portable x-ray fluorescence spectrometer

2015 ◽  
Vol 7 (1) ◽  
pp. 37-62 ◽  
Author(s):  
T. K. Udeigwe ◽  
J. Young ◽  
T. Kandakji ◽  
D. C. Weindorf ◽  
M. A. Mahmoud ◽  
...  
Keyword(s):  
Source Apportionment ◽  
Management Practices ◽  
Principal Component ◽  
The United States ◽  
Golf Course ◽  
High Plains ◽  
Urban Landscapes ◽  
Anthropogenic Influences ◽  
X Ray ◽  
Semi Arid

Abstract. This study extends the application of the portable x-ray fluorescence (PXRF) spectrometry to examination of elements in semi-arid urban landscapes of the Southern High Plains (SHP) of the United States (US), focusing on golf courses. The complex environmental challenges of this region and the unique management practices at golf course facilities could lead to differences in concentration and chemistry of elements between managed (irrigated) and non-managed (non-irrigated) portions of these facilities. Soil samples were collected at the depths of 0–10, 10–20, and 20–30 cm from managed and non-managed areas of seven different facilities in the city of Lubbock, Texas, and analyzed for a suite of soil properties. Total elemental quantification was conducted using PXRF. Findings mostly indicated no significant differences in concentration of examined elements between the managed and non-managed areas of the facilities. However, strong positive relationships (R2 = 0.82–0.91, p < 0.001) were observed among elements (e.g. Fe and each of Cr, Mn, Ni, and As; Cu and Zn; As and Cr) and between these elements and soil constituents or properties such as clay, calcium carbonate, organic matter, and pH. The strengths of these relationships were mostly higher in the non-managed areas, suggesting possible alteration in the chemistry of these elements by anthropogenic influences. Principal component analyses (PCA) and correlation analyses within the managed areas suggested that As, Cr, Fe, Mn, and Ni could be of lithogenic origin, while Cu, Pb, and Zn were attributed to anthropogenic influences. Only one possible source of element, likely lithogenic, was identified within non-managed areas. As evidenced from the study, the PXRF can be a valuable tool for elemental quantification, and rapid investigation of elemental interaction and source apportionment in semi-arid climates.

The Impact of Shariah Governance and Corporate Governance on the Risk Management Practices: Evidence from Local and Foreign Islamic Banks in Malaysia

2018 ◽  
Vol 15 (2) ◽  
pp. 1-20
Author(s):  
Sabri Embi ◽  
Zurina Shafii
Keyword(s):  
Risk Management ◽  
Corporate Governance ◽  
Management Practices ◽  
Principal Component ◽  
T Test ◽  
The Body ◽  
Primary Data ◽  
Islamic Banks ◽  
Shariah Governance ◽  
The Impact

The purpose of this study is to examine the impact of Shariah governance and corporate governance (CG) on the risk management practices (RMPs) of local Islamic banks and foreign Islamic banks operating in Malaysia. The Shariah governance comprises the Shariah review (SR) and Shariah audit (SA) variables. The study also evaluates the level of RMPs, CG, SR, and SA between these two type of banks. With the aid of SPSS version 20, the items for RMPs, CG, SR, and SA were subjected to principal component analysis (PCA). From the PCA, one component or factor was extracted each for the CG, SR, and RMPs while another two factors were extracted for the SA. Primary data was collected using a self-administered survey questionnaire. The questionnaire covers four aspects ; CG, SR, SA, and RMPs. The data received from the 300 usable questionnaires were subjected to correlation and regression analyses as well as an independent t-test. The result of correlation analysis shows that all the four variables have large positive correlations with each other indicating a strong and significant relationship between them. From the regression analysis undertaken, CG, SR, and SA together explained 52.3 percent of the RMPs and CG emerged as the most influential variable that impacts the RMPs. The independent t-test carried out shows that there were significant differences in the CG and SA between the local and foreign Islamic banks. However, there were no significant differences between the two types of the bank in relation to SR and RMPs. The study has contributed to the body of knowledge and is beneficial to academicians, industry players, regulators, and other stakeholders.

Multivariate Analysis, Genetic Diversity and Phenotypic Correlation of Nineteen Exotic Groundnut Accessions

2016 ◽  
Vol 3 (1) ◽  
Author(s):  
YPJ AMARASINGHE ◽  
G . WIJESINGHE ◽  
R W PUSHPAKUMARA
Keyword(s):  
Genetic Diversity ◽  
Principal Component Analysis ◽  
Growth Parameters ◽  
Principal Component ◽  
Phenotypic Correlation ◽  
Clustering Method ◽  
Yield Parameters ◽  
Arachis Hypogaea L ◽  
Semi Arid ◽  
Number Of Branches

19 Groundnut ( Arachis hypogaea L. ) genotypes receiv ed from International Crops Research Institute for Semi Arid T ropics (ICRISA T) India w ere ev aluated in a non replicated trial and the characters w ere subjected to multiv ariate analysis to study the v ariability within the genotypes. The first 5 axes of the principal component analysis captured 78% of the total v ariability and identified yield parameters such as number of pods per plant, pod w eight per plant and growth parameters such as number of branches per plant, plant spread, and pod characteristics as the characters contributing most to total v ariation. Phenotypic correlation analysis rev ealed that the yield has positiv e correlation with the characters such as number of pods per plant and number of branches per plant. W ards clustering method has grouped the genotypes into 3 distinct clusters. The results can be applied in order to strengthen the breeding program

scholarly journals Clustering Techniques for Secondary Substations Siting

Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 1028
Author(s):  
Silvia Corigliano ◽  
Federico Rosato ◽  
Carla Ortiz Dominguez ◽  
Marco Merlo
Keyword(s):  
Rural Areas ◽  
Urban Areas ◽  
Universal Access ◽  
Distribution Networks ◽  
Industrialized Countries ◽  
Agglomerative Clustering ◽  
Clustering Techniques ◽  
Hierarchical Agglomerative Clustering ◽  
Efficient Planning ◽  
Target Set

The scientific community is active in developing new models and methods to help reach the ambitious target set by UN SDGs7: universal access to electricity by 2030. Efficient planning of distribution networks is a complex and multivariate task, which is usually split into multiple subproblems to reduce the number of variables. The present work addresses the problem of optimal secondary substation siting, by means of different clustering techniques. In contrast with the majority of approaches found in the literature, which are devoted to the planning of MV grids in already electrified urban areas, this work focuses on greenfield planning in rural areas. K-means algorithm, hierarchical agglomerative clustering, and a method based on optimal weighted tree partitioning are adapted to the problem and run on two real case studies, with different population densities. The algorithms are compared in terms of different indicators useful to assess the feasibility of the solutions found. The algorithms have proven to be effective in addressing some of the crucial aspects of substations siting and to constitute relevant improvements to the classic K-means approach found in the literature. However, it is found that it is very challenging to conjugate an acceptable geographical span of the area served by a single substation with a substation power high enough to justify the installation when the load density is very low. In other words, well known standards adopted in industrialized countries do not fit with developing countries’ requirements.

scholarly journals Identifying organ dysfunction trajectory-based subphenotypes in critically ill patients with COVID-19

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Chang Su ◽  
Zhenxing Xu ◽  
Katherine Hoffman ◽  
Parag Goyal ◽  
Monika M. Safford ◽  
...  
Keyword(s):  
New York ◽  
Respiratory Failure ◽  
Sofa Score ◽  
Severity Of Illness ◽  
Agglomerative Clustering ◽  
Baseline Severity ◽  
Organ Systems ◽  
Hierarchical Agglomerative Clustering ◽  
Dynamic Time ◽  
Post Intubation

AbstractCOVID-19-associated respiratory failure offers the unprecedented opportunity to evaluate the differential host response to a uniform pathogenic insult. Understanding whether there are distinct subphenotypes of severe COVID-19 may offer insight into its pathophysiology. Sequential Organ Failure Assessment (SOFA) score is an objective and comprehensive measurement that measures dysfunction severity of six organ systems, i.e., cardiovascular, central nervous system, coagulation, liver, renal, and respiration. Our aim was to identify and characterize distinct subphenotypes of COVID-19 critical illness defined by the post-intubation trajectory of SOFA score. Intubated COVID-19 patients at two hospitals in New York city were leveraged as development and validation cohorts. Patients were grouped into mild, intermediate, and severe strata by their baseline post-intubation SOFA. Hierarchical agglomerative clustering was performed within each stratum to detect subphenotypes based on similarities amongst SOFA score trajectories evaluated by Dynamic Time Warping. Distinct worsening and recovering subphenotypes were identified within each stratum, which had distinct 7-day post-intubation SOFA progression trends. Patients in the worsening suphenotypes had a higher mortality than those in the recovering subphenotypes within each stratum (mild stratum, 29.7% vs. 10.3%, p = 0.033; intermediate stratum, 29.3% vs. 8.0%, p = 0.002; severe stratum, 53.7% vs. 22.2%, p < 0.001). Pathophysiologic biomarkers associated with progression were distinct at each stratum, including findings suggestive of inflammation in low baseline severity of illness versus hemophagocytic lymphohistiocytosis in higher baseline severity of illness. The findings suggest that there are clear worsening and recovering subphenotypes of COVID-19 respiratory failure after intubation, which are more predictive of outcomes than baseline severity of illness. Distinct progression biomarkers at differential baseline severity of illness suggests a heterogeneous pathobiology in the progression of COVID-19 respiratory failure.

Patterns of territory settlement by Eurasian scops-owls (Otus scops) in altered semi-arid landscapes

2007 ◽  
Vol 69 (3) ◽  
pp. 400-409 ◽  
Author(s):  
J.A. Martínez ◽  
I. Zuberogoitia ◽  
J.E. Martínez ◽  
J. Zabala ◽  
J.F. Calvo
Keyword(s):  
Arid Landscapes ◽  
Semi Arid
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