scholarly journals Spatial prediction of spring locations in data poor region of Central Himalayas

2020 ◽  
Author(s):  
Rabin Raj Niraula ◽  
Subodh Sharma ◽  
Bharat K. Pokharel ◽  
Uttam Paudel
Keyword(s):  
Bootstrap Method ◽  
Spatial Prediction ◽  
Supporting Evidence ◽  
True Negative ◽  
Causal Factors ◽  
Central Himalayas ◽  
Poor Region ◽  
Random Forest Models ◽  
High Prediction ◽  
Groundwater Springs

Abstract This research explores the methods for understanding groundwater springs distribution and occurrence using Geographic Information System (GIS) and Machine Learning technique in data poor areas of the Central Himalayas. The objectives of this study are to analyse the distribution of natural springs, evaluate three random forest models for its predictability and establish a model for the prediction of occurrence of springs. This study evaluates the primary causal factors for occurrence of springs. The data used in this study consists of 20 parameters based on topography, geology, lithology, hydrology and land use as causal factors, whereas 621 spring location and discharge (n = 621) measured during 2014–2016 and 815 non-spring locations (generated by GIS tool) use as supporting evidence to train (80%) and test (20%) the prediction model. Results show that the Bootstrap method is comparatively reliable (92% accuracy) over Boosted tree (64% accuracy) and Decision tree (74% accuracy) methods to classify and predict the occurrence of springs in the watershed. Bootstrap Forest shows the high Prediction rate for True Positive (82% actual spring predicted as a spring) and True Negative (89% actual non-spring predicted as non-spring), and the model seems consistent in both responses. This model was then applied to an independent dataset to predict spring location estimates with 75% accuracy. Therefore, spatial statistical methods prove efficient at predicting spring occurrence in data poor regions.

Etiology of intracranial berry aneurysms

1989 ◽  
Vol 70 (6) ◽  
pp. 823-831 ◽  
Author(s):  
William E. Stehbens
Keyword(s):  
Scientific Data ◽  
Supporting Evidence ◽  
Collateral Flow ◽  
Connective Tissue Disorders ◽  
Connective Tissues ◽  
Aneurysmal Dilatation ◽  
Causal Factors ◽  
Content Type ◽  
Hemodynamic Stress ◽  
Feeding Vessels

✓ The congenital theory of the etiology of intracranial berry aneurysms has been widely accepted for manyyears. Review of the supporting evidence indicates that it is not based on sound scientific data but on unscientific and unsubstantiated allegations. There is no evidence of a congenital, developmental, or inherited weakness of the vessel wall. The most plausible explanation is that the aneurysms are acquired degenerative lesions — the effect of hemodynamic stress. The mural atrophy leading to aneurysmal dilatation is an acquired lesion which can be produced experimentally by hemodynamics alone. Hypertension and connective tissue disorders associated with acquired loss of tensile strength of the connective tissues are not essential: they appear to be aggravating rather than causal factors. Occlusion of one or more feeding vessels may enhance the possibility of aneurysm formation at large arterial forks subjected to the augmented hemodynamic stress associated with collateral flow.

scholarly journals Imputing Satellite-Derived Aerosol Optical Depth Using a Multi-Resolution Spatial Model and Random Forest for PM2.5 Prediction

2021 ◽  
Vol 13 (1) ◽  
pp. 126
Author(s):  
Behzad Kianian ◽  
Yang Liu ◽  
Howard H. Chang
Keyword(s):  
Random Forest ◽  
Aerosol Optical Depth ◽  
Optical Depth ◽  
Ensemble Methods ◽  
Predictive Performance ◽  
Spatial Prediction ◽  
Gap Filling ◽  
Environmental Health Research ◽  
Random Forest Models ◽  
Pollution Exposure

A task for environmental health research is to produce complete pollution exposure maps despite limited monitoring data. Satellite-derived aerosol optical depth (AOD) is frequently used as a predictor in various models to improve PM2.5 estimation, despite significant gaps in coverage. We analyze PM2.5 and AOD from July 2011 in the contiguous United States. We examine two methods to aid in gap-filling AOD: (1) lattice kriging, a spatial statistical method adapted to handle large amounts data, and (2) random forest, a tree-based machine learning method. First, we evaluate each model’s performance in the spatial prediction of AOD, and we additionally consider ensemble methods for combining the predictors. In order to accurately assess the predictive performance of these methods, we construct spatially clustered holdouts to mimic the observed patterns of missing data. Finally, we assess whether gap-filling AOD through one of the proposed ensemble methods can improve prediction of PM2.5 in a random forest model. Our results suggest that ensemble methods of combining lattice kriging and random forest can improve AOD gap-filling. Based on summary metrics of performance, PM2.5 predictions based on random forest models were largely similar regardless of the inclusion of gap-filled AOD, but there was some variability in daily model predictions.

Text Comprehension: Graphic Organizers to the Rescue

2009 ◽  
Vol 10 (3) ◽  
pp. 82-89
Author(s):  
Janet L. Proly ◽  
Jessica Rivers ◽  
Jamie Schwartz
Keyword(s):  
Reading Comprehension ◽  
Text Comprehension ◽  
Graphic Organizers ◽  
Expository Text ◽  
Supporting Evidence

Abstract Graphic organizers are a research based strategy used for facilitating the reading comprehension of expository text. This strategy will be defined and the evolution and supporting evidence for the use of graphic organizers will be discussed. Various types of graphic organizers and resources for SLPs and other educators will also be discussed.

An Application of the HFACS Method to Aviation Accidents in Africa

2016 ◽  
Vol 6 (1) ◽  
pp. 33-38 ◽  
Author(s):  
Isaac Munene
Keyword(s):  
Human Factors ◽  
Physical Environment ◽  
Human Factor ◽  
Flight Training ◽  
African Countries ◽  
Causal Factors ◽  
Aviation Accidents ◽  
Factors Analysis ◽  
Adverse Weather ◽  
Decision Errors

Abstract. The Human Factors Analysis and Classification System (HFACS) methodology was applied to accident reports from three African countries: Kenya, Nigeria, and South Africa. In all, 55 of 72 finalized reports for accidents occurring between 2000 and 2014 were analyzed. In most of the accidents, one or more human factors contributed to the accident. Skill-based errors (56.4%), the physical environment (36.4%), and violations (20%) were the most common causal factors in the accidents. Decision errors comprised 18.2%, while perceptual errors and crew resource management accounted for 10.9%. The results were consistent with previous industry observations: Over 70% of aviation accidents have human factor causes. Adverse weather was seen to be a common secondary casual factor. Changes in flight training and risk management methods may alleviate the high number of accidents in Africa.

Causal Factors of Gulf War Illness

2006 ◽  
Author(s):  
Katherine N. Nguyen ◽  
Kendal C. Boyd
Keyword(s):  
Gulf War ◽  
Gulf War Illness ◽  
Causal Factors

Over-All Accuracy of 99mTc-Pertechnetate Brain Scanning for Brain Tumours – Study of 471 Patients

1978 ◽  
Vol 17 (06) ◽  
pp. 249-253
Author(s):  
E. Pétursson ◽  
B. Sigurbjörnsson ◽  
D. Davidsson ◽  
O.G. Björnsson
Keyword(s):  
Brain Metastases ◽  
Brain Tumours ◽  
True Negative ◽  
Diagnostic Reliability ◽  
Radioisotope Scanning ◽  
Primary Brain Tumours ◽  
99Mtc Pertechnetate

A 3-year follow-up and re-evaluation of all scans on all patients referred for brain scanning in Iceland during 1 year was performed in order to assess the diagnostic reliability of radioisotope scanning for brain tumours. The study included 471 patients. Of these 25 had primary brain tumours and 7 brain metastases. Scans were positive and correctly interpreted in68 % of the patients with primary brain tumours and in 3 of the 7 patients with metastases. The over-all accuracy of brain scanning for brain tumours defined as the total number of correct positive scans and correct negative scans versus total number of scans examined was 96%, this figure being mainly influenced by the high number of true negative scans.

Experimentally increased costs of parental care are shunted to offspring in species with extended care

2019 ◽  
Author(s):  
Gretchen F. Wagner ◽  
Emeline Mourocq ◽  
Michael Griesser
Keyword(s):  
Life History ◽  
Parental Care ◽  
Total Duration ◽  
Bird Species ◽  
Life History Strategy ◽  
Experimental Treatment ◽  
Cost Of Care ◽  
Adult Survival ◽  
Supporting Evidence ◽  
Trade Offs

Biparental care systems are a valuable model to examine conflict, cooperation, and coordination between unrelated individuals, as the product of the interactions between the parents influences the fitness of both individuals. A common experimental technique for testing coordinated responses to changes in the costs of parental care is to temporarily handicap one parent, inducing a higher cost of providing care. However, dissimilarity in experimental designs of these studies has hindered interspecific comparisons of the patterns of cost distribution between parents and offspring. Here we apply a comparative experimental approach by handicapping a parent at nests of five bird species using the same experimental treatment. In some species, a decrease in care by a handicapped parent was compensated by its partner, while in others the increased costs of care were shunted to the offspring. Parental responses to an increased cost of care primarily depended on the total duration of care that offspring require. However, life history pace (i.e., adult survival and fecundity) did not influence parental decisions when faced with a higher cost of caring. Our study highlights that a greater attention to intergenerational trade-offs is warranted, particularly in species with a large burden of parental care. Moreover, we demonstrate that parental care decisions may be weighed more against physiological workload constraints than against future prospects of reproduction, supporting evidence that avian species may devote comparable amounts of energy into survival, regardless of life history strategy.

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