scholarly journals Retention and Dimensional Changes of Supplemental Evergreen Brush Piles within a Flood Control Reservoir

2021 ◽  
Author(s):  
Caleb Aldridge ◽  
David M Norris ◽  
Hunter R Hatcher ◽  
Giancarlo Coppola ◽  
Leandro E Miranda ◽  
...  
Keyword(s):  
Spatial Patterns ◽  
Flood Control ◽  
Woody Debris ◽  
Fish Habitat ◽  
Dimensional Change ◽  
Volume Estimation ◽  
Computer Assisted ◽  
Juniperus Virginiana ◽  
Data Set ◽  
Annual Cycles

Brush piles (i.e., trees and large woody debris) are often installed in reservoirs to supplement fish habitat. The retention and dimensional change of brush piles after installation is important information that can be used to maximize the effectiveness of this management action. We evaluated the retention and dimensional change of 70 eastern red cedar Juniperus virginiana and bald cypress Taxodium distichum brush piles in an embayment of a drawdown reservoir up to four annual cycles of submergence and exposure. We used satellite imagery to supplement our onsite measurements of retention. We also examined spatial patterns of brush pile retention and dimensional change. Brush piles were lost at 10% per year and their volume at 14% per year. We compared our rates of brush pile retention and dimensional change with those from a holdout data set of 50 brush piles. Estimates between data sets did not differ statistically. Spatial patterns of retention and dimensional change coincided with morphological features in our study area, suggesting that retention and dimensional change is influenced by variable physical forces (e.g., wave action and flow) at installation locations. Our estimates of brush pile retention and dimensional change can be used to generally sustain desirable brush densities. For example, to maintain a fixed total volume of brush in our study embayment roughly 23% of the total brush volume installed would need to be replaced annually. Similar research in reservoirs managed for other purposes is needed as length and cycle of inundation could lead to variable rates of retention and dimensional change. Additionally, advancements into computer-assisted detection and volume estimation could reduce the time and effort needed to monitor brush piles.

Relationships between riverine fish and woody debris: implications for lowland rivers

1999 ◽  
Author(s):  
D. A. Crook ◽  
A. I. Robertson
Keyword(s):  
Woody Debris ◽  
Fish Habitat ◽  
Reference Points ◽  
Positive Development ◽  
Lowland River ◽  
Predator Prey ◽  
Lowland Rivers ◽  
Habitat Features ◽  
Surface Areas ◽  
Riverine Fish

This paper reviews studies of relationships between riverine fish and woody debris at micro- and meso-habitat scales, and discusses the potential functions of instream structure for lowland river fish. Experimental research, mainly in North America, has identified three main functions of woody debris as microhabitat for fish in upland streams: overhead cover that decreases predation risk both vertically and horizontally; horizontal visual isolation that reduces contact between fish; and velocity refuge which minimizes energetic costs. As with habitat features in other aquatic environments, increasing spatial complexity of woody debris may modify predator–prey interactions and provide greater surface areas for the growth of prey items. Woody debris may also provide spatial reference points for riverine fish to assist them in orienting within their surroundings. Lowland rivers differ from upland streams in terms of a number of physical variables, including turbidity, depth and water turbulence. Relationships between fish and woody debris in lowland rivers are likely to rely on mechanisms different to those in upland streams. Recent initiatives involving the reintroduction of woody debris into previously cleared lowland rivers to replace lost fish habitat are a positive development for lowland river restoration. However, if woody debris reintroduction is to maximally benefit lowland river fisheries, there is a requirement for better understanding of the ecological functions of woody debris in lowland rivers.

The influence of aneurysm morphology on the volume of hemorrhage after rupture

2021 ◽  
pp. 1-9
Author(s):  
Pablo M. Munarriz ◽  
Blanca Navarro-Main ◽  
Jose F. Alén ◽  
Luis Jiménez-Roldán ◽  
Ana M. Castaño-Leon ◽  
...  
Keyword(s):  
Subarachnoid Hemorrhage ◽  
Univariate Analysis ◽  
Size Ratio ◽  
Computer Assisted ◽  
Data Set ◽  
Aneurysm Size ◽  
Risk Of Rupture ◽  
Morphological Variables ◽  
Hemorrhage Volume ◽  
The Impact

OBJECTIVE Factors determining the risk of rupture of intracranial aneurysms have been extensively studied; however, little attention is paid to variables influencing the volume of bleeding after rupture. In this study the authors aimed to evaluate the impact of aneurysm morphological variables on the amount of hemorrhage. METHODS This was a retrospective cohort analysis of a prospectively collected data set of 116 patients presenting at a single center with subarachnoid hemorrhage due to aneurysmal rupture. A volumetric assessment of the total hemorrhage volume was performed from the initial noncontrast CT. Aneurysms were segmented and reproduced from the initial CT angiography study, and morphology indexes were calculated with a computer-assisted approach. Clinical and demographic characteristics of the patients were included in the study. Factors influencing the volume of hemorrhage were explored with univariate correlations, multiple linear regression analysis, and graphical probabilistic modeling. RESULTS The univariate analysis demonstrated that several of the morphological variables but only the patient’s age from the clinical-demographic variables correlated (p < 0.05) with the volume of bleeding. Nine morphological variables correlated positively (absolute height, perpendicular height, maximum width, sac surface area, sac volume, size ratio, bottleneck factor, neck-to-vessel ratio, and width-to-vessel ratio) and two correlated negatively (parent vessel average diameter and the aneurysm angle). After multivariate analysis, only the aneurysm size ratio (p < 0.001) and the patient’s age (p = 0.023) remained statistically significant. The graphical probabilistic model confirmed the size ratio and the patient’s age as the variables most related to the total hemorrhage volume. CONCLUSIONS A greater aneurysm size ratio and an older patient age are likely to entail a greater volume of bleeding after subarachnoid hemorrhage.

Computer-assisted Diagnosis for Early Stage Pleural Mesothelioma

2007 ◽  
Vol 46 (03) ◽  
pp. 324-331 ◽  
Author(s):  
P. Jäger ◽  
S. Vogel ◽  
A. Knepper ◽  
T. Kraus ◽  
T. Aach ◽  
...  
Keyword(s):  
Early Stage ◽  
Computation Time ◽  
Hounsfield Unit ◽  
Computer Assisted ◽  
Clinical Test ◽  
Pleural Mesothelioma ◽  
Data Sets ◽  
Data Set ◽  
Average Computation Time ◽  
Ct Data

Summary Objectives: Pleural thickenings as biomarker of exposure to asbestos may evolve into malignant pleural mesothelioma. Foritsearly stage, pleurectomy with perioperative treatment can reduce morbidity and mortality. The diagnosis is based on a visual investigation of CT images, which is a time-consuming and subjective procedure. Our aim is to develop an automatic image processing approach to detect and quantitatively assess pleural thickenings. Methods: We first segment the lung areas, and identify the pleural contours. A convexity model is then used together with a Hounsfield unit threshold to detect pleural thickenings. The assessment of the detected pleural thickenings is based on a spline-based model of the healthy pleura. Results: Tests were carried out on 14 data sets from three patients. In all cases, pleural contours were reliably identified, and pleural thickenings detected. PC-based Computation times were 85 min for a data set of 716 slices, 35 min for 401 slices, and 4 min for 75 slices, resulting in an average computation time of about 5.2 s per slice. Visualizations of pleurae and detected thickeningswere provided. Conclusion: Results obtained so far indicate that our approach is able to assist physicians in the tedious task of finding and quantifying pleural thickenings in CT data. In the next step, our system will undergo an evaluation in a clinical test setting using routine CT data to quantifyits performance.

scholarly journals The political biogeography of migratory marine predators

2019 ◽  
Author(s):  
Autumn-Lynn Harrison
Keyword(s):  
Pacific Ocean ◽  
The Political ◽  
Migratory Species ◽  
Data Set ◽  
Leatherback Turtles ◽  
Annual Cycles ◽  
Marine Predators ◽  
The Pacific ◽  
The Pacific Ocean ◽  
International Strategies

We synthesized a large tracking data set from the Tagging of Pacific Predators to show how the movements and migratory phenology of 1,648 individuals representing 14 species—from leatherback turtles to white sharks—relate to the geopolitical boundaries of the Pacific Ocean throughout species’ annual cycles. Cumulatively, these species visited 86% of Pacific Ocean countries and some spent three-quarters of their annual cycles in the high seas. With our results, we offer answers to questions posed when designing international strategies for managing migratory species.

scholarly journals Improving Spleen Volume Estimation Via Computer-assisted Segmentation on Clinically Acquired CT Scans

2016 ◽  
Vol 23 (10) ◽  
pp. 1214-1220 ◽  
Author(s):  
Zhoubing Xu ◽  
Adam L. Gertz ◽  
Ryan P. Burke ◽  
Neil Bansal ◽  
Hakmook Kang ◽  
...  
Keyword(s):  
Volume Estimation ◽  
Ct Scans ◽  
Computer Assisted ◽  
Spleen Volume

No simple relationship between above-ground tree growth and fine-litter production in tropical forests

2008 ◽  
Vol 24 (3) ◽  
pp. 347-350 ◽  
Author(s):  
Luke P. Shoo ◽  
Jeremy VanDerWal
Keyword(s):  
Missing Data ◽  
Primary Productivity ◽  
Net Primary Productivity ◽  
Woody Debris ◽  
Litter Production ◽  
Simple Relationship ◽  
Above Ground Biomass ◽  
Data Set ◽  
Geographic Coverage ◽  
Incremental Growth

An important deficiency of the tropical forest data set on above-ground net primary productivity (ANPP) is the paucity of studies where requisite components of forest productivity have been measured at the same location. Missing data on above-ground biomass increment (ABI, which refers to the incremental growth of trees) and fine-litter production (leaves, fruit, flowers, small twigs, but excluding coarse woody debris) is particularly problematic as these are the two major components of ANPP. The fragmentary nature of the data is reflected by the fact that only 13 of 39 (33%) plots reviewed by Clark et al. (2001) and 8 of 104 (8%) plots reviewed by Malhi et al. (2004) had data on both major components of productivity. In an attempt to retain the geographic coverage and replication of data in analyses, researchers have proposed ways to infer missing data. Typically ratios or (more recently) fitted relationships between ABI and litter production have been used for this purpose (Bray & Gorham 1964, Clark et al. 2001, Murphy 1975).

scholarly journals Are Australians ready for warning labels, marketing bans and sugary drink taxes? Two cross-sectional surveys measuring support for policy responses to sugar-sweetened beverages

BMJ Open ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. e027962 ◽  
Author(s):  
Caroline L Miller ◽  
Joanne Dono ◽  
Melanie A Wakefield ◽  
Simone Pettigrew ◽  
John Coveney ◽  
...  
Keyword(s):  
Obesity Prevention ◽  
Public Support ◽  
Survey Study ◽  
Absolute Difference ◽  
National Study ◽  
Computer Assisted ◽  
Warning Labels ◽  
Cross Sectional ◽  
Data Set ◽  
Policy Initiatives

ObjectiveTo assess public support for 10 potential policy initiatives to reduce sugar-sweetened beverage (SSB) consumption.DesignA 2014 historical data set, which employed a face-to-face survey in one Australian state (study 1), provided the basis for comparison with our 2017 nationally representative, cross-sectional, computer-assisted telephone interviewing population survey (study 2).ParticipantsStudy 1: South Australians, 15+ years (n=2732); study 2: Australians, 18+ years (n=3430).Primary outcome measures: levels of support for SSB-specific policy initiatives. For the 2017 national study (study 2), demographic characteristics, body mass index, knowledge of potential harms caused by consuming SSBs and SSB consumption were included in multivariable regression analyses.ResultsIn 2017, all 10 potential policy initiatives received majority support (60%–88% either ‘somewhat’ or ‘strongly’ in favour). Initiatives with educative elements or focused on children received high support (>70%), with highest support observed for text warning labels on drink containers (88%) and government campaigns warning of adverse health effects (87%). Higher support was observed for SSB tax paired with using funds for obesity prevention (77%) than a stand-alone tax (60%). Support for policy initiatives was generally greater among those who believed SSB daily consumption could cause health problems in adults (4%–18% absolute difference) and/or in children (8%–26% absolute difference) and lower among SSB high consumers (7+ drinks per week; 9%–29% absolute difference). State-specific data comparison indicated increased support from 2014 to 2017 for taxation (42%vs55%; χ2=15.7, p<0.001) and graphic health warnings (52%vs68%; χ2=23.4. p<0.001).ConclusionsThere is strong public support for government action, particularly regulatory and educational interventions, to reduce SSB consumption, which appears to have increased since 2014. The findings suggest that framing policies as protecting children, presenting taxation of SSBs in conjunction with other obesity prevention initiatives and education focused on the harms associated with SSB consumption will increase support.

scholarly journals Comparison of Large Woody Debris Prototypes in a Large Scale Non-flume Physical Model

2018 ◽  
Vol 40 ◽  
pp. 05010
Author(s):  
Brian Perry ◽  
Colin Rennie ◽  
Andrew Cornett ◽  
Paul Knox
Keyword(s):  
Physical Model ◽  
Flood Control ◽  
Large Scale ◽  
Woody Debris ◽  
Water Levels ◽  
Mitigation Strategies ◽  
Large Woody Debris ◽  
Debris Accumulation ◽  
The Impact ◽  
The City

Due to excessive rainfall in June of 2013, several rivers located in and near the City of Calgary, Canada experienced significant flooding events. These events caused severe damage to infrastructure throughout the city, precipitating a renewed interest in flood control and mitigation strategies for the area. A major potential strategy involves partial diversion of Elbow River flood water to the proposed Springbank Off-Stream Storage Reservoir. A large scale physical model study was conducted to optimize and validate the design of a portion of the new project. The goals of the physical model were to investigate diversion system behaviors such as flow rates, water levels, sediment transport and, debris accumulation, and optimize the design of new flow control structures to be constructed on the Elbow River. In order to accurately represent the behavior of debris within the system due to flooding, large woody debris created from natural sources was utilized in the physical model and its performance was compared to that of debris of the same size fabricated from pressed cylindrical wood dowels. In addition to comparing the performance of these two debris types, the impact of root wads on debris damming was also investigated. Significant differences in damming behavior was shown to exist between the natural debris and the fabricated debris, while the impact of root wad on damming affected the dam structure and formation. The results of this experiment indicate that natural debris is preferred for studies involving debris accumulation.

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