Use of multivariate methods in forest research site selection

1991 ◽  
Vol 21 (11) ◽  
pp. 1573-1580 ◽  
Author(s):  
Andrew J. Burton ◽  
Carl W. Ramm ◽  
Kurt S. Pregitzer ◽  
David D. Reed
Keyword(s):  
Site Selection ◽  
Large Scale ◽  
Multivariate Methods ◽  
Data Bases ◽  
Principal Coordinates Analysis ◽  
Research Site ◽  
Principal Coordinates ◽  
Alternative Sites ◽  
Existing Data ◽  
Selection Of

In large-scale gradient studies, selection of the best research sites is critical but time-consuming and costly. Multivariate methods can be used to quickly identify suitable sites from existing data bases. Based on a study of acid deposition in the Great Lakes region (the Michigan Gradient Study), we illustrate the use of multivariate methods in screening potential research sites for similarity. Sites were examined using cluster analysis, principal coordinates analysis, and correspondence analysis. The graphical displays generated by the multivariate methods were used to identify similar sites across the gradient. A list of 31 potential sites was reduced to 5 similar research sites and several alternative sites. The results of the multivariate methods compared well with more traditional methods of research site selection but allowed for multiple comparisons of many potential sites using a variety of data from existing data bases. By eliminating sites that are unacceptable with respect to available data, the multivariate methods reduce the number of sites that require field visitation prior to final site verification. This process represents a substantial savings in time and effort when dealing with a long list of potential research sites.

scholarly journals Scientific Site Selection of Ancient Large-scale Underground Quarries from Engineering Geology: A Case of Shepan Island in Sanmen, China

2016 ◽  
Vol 10 (1) ◽  
pp. 720-726
Author(s):  
Guangxiang Yuan ◽  
Jianyong Li ◽  
Zhiquan Huang ◽  
Zhifa Yang
Keyword(s):  
Site Selection ◽  
Large Scale ◽  
Engineering Geology ◽  
Upper Jurassic ◽  
Mechanical Tests ◽  
Zhejiang Province ◽  
Geological Condition ◽  
Engineering Geological Condition ◽  
Clastic Rock ◽  
Selection Of

There are many ancient underground quarries in Zhejiang Province, China. Many caverns of them maintained steady more than 1000 years. Certain engineering geological condition is very important for long-term stability. In this paper, ancient underground quarries in Shepan Island are presented as a case. Shepan Island ancient large-scale underground quarry caverns are located in Sanmen County, Zhejiang Province. These caverns were excavated more than 800 years ago and at least 1300 of them are reserved until now. Shepan Island is a hill which uplifts the continental shelf extending to the gulf. There are no large regional fractures through caverns area, which indicates that it belongs to earthquake stability region. The caverns were excavated in thick volcanic clastic rock formed in the upper Jurassic, with NW and NE faults and NW joints. Based on the study of rock weathering, physical and mechanical tests of rock samples, and inverse analysis of structural plane, the huge thick volcano clastic rock can be classified as block structure. In addition, groundwater which affects the stability of caverns was analyzed based on the investigations of hydrogeological conditions. Site selection of ancient large-scale underground quarries is query scientific from modern engineering geology point of view.

The denning behaviour of dingoes (Canis dingo) living in a human-modified environment

2017 ◽  
Vol 39 (2) ◽  
pp. 161 ◽  
Author(s):  
Bradley Smith ◽  
Anne-Louise Vague
Keyword(s):  
Site Selection ◽  
Large Scale ◽  
Mining Operation ◽  
Breeding Site ◽  
Sandy Desert ◽  
Surrounding Area ◽  
Den Site Selection ◽  
Close Proximity ◽  
Free Ranging ◽  
Selection Of

Little is known about reproduction and den site selection by free-ranging dingoes. We present observations of den sites used by dingoes inhabiting a large-scale mining operation located in the Great Sandy Desert, Western Australia. We observed 24 dens concentrated within a 1-km radius. Den sites were generally situated in elevated positions overlooking the surrounding area, were a short distance from food and water resources, required vegetation (particularly spinifex grass) to provide a firm foundation and stable ceiling in the soft sand, and had single den openings that faced away from the rising and daytime sun. Distance to human structures or activity did not appear to influence site selection. Four of the dens were active, containing a total of 37 pups aged between two and four weeks of age. One den contained 18 pups of different ages, indicating that communal denning was also occurring. The high number of breeding females within close proximity suggests that multiple family groups are able to share resources and live in close proximity. Our findings highlight the importance of human-modified areas and abundance of resources in the reproduction and breeding site selection of dingoes.

scholarly journals Major ocean currents may shape the microbiome of the topshell Phorcus sauciatus in the NE Atlantic Ocean

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ricardo Sousa ◽  
Joana Vasconcelos ◽  
Iván Vera-Escalona ◽  
João Delgado ◽  
Mafalda Freitas ◽  
...  
Keyword(s):  
Large Scale ◽  
Alpha Diversity ◽  
Marine Species ◽  
Principal Coordinates Analysis ◽  
Study Region ◽  
The North ◽  
Mainland Portugal ◽  
Model Study ◽  
Principal Coordinates ◽  
Ne Atlantic Ocean

AbstractStudies on microbial communities are pivotal to understand the role and the evolutionary paths of the host and their associated microorganisms in the ecosystems. Meta-genomics techniques have proven to be one of the most effective tools in the identification of endosymbiotic communities of host species. The microbiome of the highly exploited topshell Phorcus sauciatus was characterized in the Northeastern Atlantic (Portugal, Madeira, Selvagens, Canaries and Azores). Alpha diversity analysis based on observed OTUs showed significant differences among regions. The Principal Coordinates Analysis of beta-diversity based on presence/absence showed three well differentiated groups, one from Azores, a second from Madeira and the third one for mainland Portugal, Selvagens and the Canaries. The microbiome results may be mainly explained by large-scale oceanographic processes of the study region, i.e., the North Atlantic Subtropical Gyre, and specifically by the Canary Current. Our results suggest the feasibility of microbiome as a model study to unravel biogeographic and evolutionary processes in marine species with high dispersive potential.

Platelet Anti-Aggregating Activity and Tolerance of Clopidogrel in Atherosclerotic Patients

1996 ◽  
Vol 76 (06) ◽  
pp. 0939-0943 ◽  
Author(s):  
B Boneu ◽  
G Destelle ◽  
Keyword(s):  
Platelet Aggregation ◽  
Large Scale ◽  
Bleeding Time ◽  
Antithrombotic Activity ◽  
Ambulatory Patients ◽  
Patients At Risk ◽  
Set Up ◽  
Ischemic Events ◽  
Large Scale Clinical Trial ◽  
Selection Of

SummaryThe anti-aggregating activity of five rising doses of clopidogrel has been compared to that of ticlopidine in atherosclerotic patients. The aim of this study was to determine the dose of clopidogrel which should be tested in a large scale clinical trial of secondary prevention of ischemic events in patients suffering from vascular manifestations of atherosclerosis [CAPRIE (Clopidogrel vs Aspirin in Patients at Risk of Ischemic Events) trial]. A multicenter study involving 9 haematological laboratories and 29 clinical centers was set up. One hundred and fifty ambulatory patients were randomized into one of the seven following groups: clopidogrel at doses of 10, 25, 50,75 or 100 mg OD, ticlopidine 250 mg BID or placebo. ADP and collagen-induced platelet aggregation tests were performed before starting treatment and after 7 and 28 days. Bleeding time was performed on days 0 and 28. Patients were seen on days 0, 7 and 28 to check the clinical and biological tolerability of the treatment. Clopidogrel exerted a dose-related inhibition of ADP-induced platelet aggregation and bleeding time prolongation. In the presence of ADP (5 \lM) this inhibition ranged between 29% and 44% in comparison to pretreatment values. The bleeding times were prolonged by 1.5 to 1.7 times. These effects were non significantly different from those produced by ticlopidine. The clinical tolerability was good or fair in 97.5% of the patients. No haematological adverse events were recorded. These results allowed the selection of 75 mg once a day to evaluate and compare the antithrombotic activity of clopidogrel to that of aspirin in the CAPRIE trial.

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