A comparison of the relationship between measured acoustic response and porosity in carbonates across different geologic periods, depositional basins, and with variable mineral composition

2018 ◽  
Vol 6 (2) ◽  
pp. T245-T256
Author(s):  
Beth Vanden Berg ◽  
Christophe Nussbaumer ◽  
Amy Noack ◽  
John Thornton ◽  
Ralf J. Weger ◽  
...  
Keyword(s):  
Carbonate Platform ◽  
Order Estimate ◽  
Michigan Basin ◽  
Limited Data ◽  
Data Set ◽  
Paradox Basin ◽  
Great Bahama Bank ◽  
Wide Range ◽  
Basic Relationship ◽  
The Relationship

Recent work has shown that there is a predictable inverse relationship between laboratory-measured sonic velocity response and porosity in carbonates, which can be reasonably approximated using the empirical Wyllie time-average equation (WTA). The relationship was initially identified in late Cretaceous to Cenozoic age samples collected from the Great Bahama Bank and the Maiella Platform, an exhumed Cretaceous carbonate platform in Italy. We have compared older carbonate samples from different basins and different geologic ages to determine the applicability of this relationship and subsequent correlations to key petrophysical properties to other carbonate basins and other geologic time periods. The data set used for the comparison shows this relationship to be relatively consistent in other depositional basins (Michigan Basin, Paradox Basin) and with samples from older geologic periods (Pennsylvanian, Ordovician, and Mississippian). However, this basic relationship is also observed to vary significantly within a reservoir system and within a depositional basin in samples from different geologic periods (e.g., Silurian- versus Ordovician-age rocks in the Michigan Basin). Although the empirical WTA can generally be applied as a first-order estimate across a wide range of sample ages in carbonates, limited data suggest the relationship between velocity and porosity to be moderately more complex. For instance, in unconventional carbonate reservoirs characterized by predominantly micro- to nanoscale porosity, it is observed that the WTA should be applied as an upper data boundary. In addition, this study has shown that the relationship to the dominant pore type is less direct than in a macropore system in which it can be assumed that the dominant pore type also has the greatest effect on the effective permeability.

scholarly journals The relationship between volume increment and stand density in Norway spruce plantations

2020 ◽  
Author(s):  
Micky Allen ◽  
Andreas Brunner ◽  
Clara Antón-Fernández ◽  
Rasmus Astrup
Keyword(s):  
Norway Spruce ◽  
Basal Area ◽  
Stand Density ◽  
Management Objectives ◽  
Wide Range ◽  
Volume Increment ◽  
Basic Relationship ◽  
Stand Density Index ◽  
The Relationship ◽  
Experimental Plots

Abstract An understanding of the relationship between volume increment and stand density (basal area, stand density index, etc.) is of utmost importance for properly managing stand density to achieve specific management objectives. There are two main approaches to analyse growth–density relationships. The first relates volume increment to stand density through a basic relationship, which can vary with site productivity, age, and potentially incorporates treatment effects. The second is to relate the volume increment and density of thinned experimental plots relative to that of an unthinned experimental plot on the same site. Using a dataset of 229 thinned and unthinned experimental plots of Norway spruce, a growth model is developed describing the relationship between gross or net volume increment and basal area. The models indicate that gross volume increases with increasing basal area up to 50 m2 and thereafter becomes constant out to the maximum basal area. Alternatively, net volume increment was maximized at a basal area of 43 m2 and decreased with further increases in basal area. However, the models indicated a wide range where net volume increment was essentially constant, varying by less than 1 m3 ha−1 year−1. An analysis of different thinning scenarios indicated that the relative relationship between volume increment and stand density was dynamic and changed over the course of a rotation.

scholarly journals Persistence of dry matter yield among New Zealand perennial ryegrass (Lolium perenne L.) cultivars: insights from a long-term data set

2015 ◽  
Vol 77 ◽  
pp. 177-184 ◽  
Author(s):  
D.F. Chapman ◽  
P.D. Muir ◽  
M.J. Faville
Keyword(s):  
New Zealand ◽  
Perennial Ryegrass ◽  
Dry Matter ◽  
Heading Date ◽  
Early Years ◽  
Grass Species ◽  
Data Set ◽  
High Performing ◽  
Wide Range ◽  
The Relationship

Persistence of herbage yield is an important productivity trait of grass species and cultivars in New Zealand pastures. However, relatively little is known about genetic variation in this trait, principally because few studies comparing yield have continued beyond 3 years. This paper reports results from a comparison of 25 perennial ryegrass cultivars representing a wide range of functional types and genetic backgrounds conducted under sheep grazing in a summer-dry environment. Dry matter (DM) yield was measured for the first 3 years after sowing, then again in years seven and eight post-sowing, and in year ten post-sowing. Endophyte DNA fingerprinting conducted mid-way through year seven confirmed that, with one exception, ryegrass populations remained true-to-type in the cultivars sown with novel endophyte strains. The cultivar effect on DM yield was statistically significant in all measurement periods. Differences in yields among cultivars in years seven and eight were significantly and positively correlated with yield differences in years one to three (r=0.685 to 0.831 depending on which year contrasts were used). Thus, high-performing cultivars in the early years of the trial were also generally highperforming cultivars in years seven and eight, and vice-versa, indicating a high degree of yield stability in perennial ryegrass cultivars. Yield differences did not appear to be related to differences in cultivar heading date, ploidy, endophyte status, or genetic background. The relationship between yield in year ten and yields in years one to three was much weaker (r=0.392) than the relationship in years seven and eight. Possible reasons for this are discussed. Keywords: Perennial ryegrass; traits; persistence

scholarly journals Vestibular Characteristics of Patients with Chronic Rhinosinusitis

OTO Open ◽  
2018 ◽  
Vol 2 (4) ◽  
pp. 2473974X1880499
Author(s):  
Sabrina Brody-Camp ◽  
John A. Risey ◽  
Edward D. McCoul
Keyword(s):  
Chronic Rhinosinusitis ◽  
Preliminary Report ◽  
Vestibular Function ◽  
Subjective Symptom ◽  
Common Disease ◽  
Disease Entity ◽  
Limited Data ◽  
Wide Range ◽  
The Relationship ◽  
Prospective Database

Chronic rhinosinusitis (CRS) is a common disease entity with symptoms that may extend beyond the sinonasal tract. Limited data exist regarding the relationship between CRS and the vestibular system, and no previous study has investigated the association between objective vestibular findings on videonystagmography (VNG) and the diagnosis of CRS. We analyzed a prospective database of 3078 patients who underwent VNG at our institution over an 8-year period, which included 70 subjects who had a diagnosis of CRS assigned by an otolaryngologist. Overall, the VNG findings for patients with CRS were similar to those of the general population, with 50% exhibiting normal vestibular function. Peripheral lesions were the most common abnormal VNG finding, with a wide range of subjective symptom descriptions. This preliminary report of the prevalence of objective vestibular findings in patients with CRS may form the basis for future study.

A single-center analysis of initial imaging in multiple myeloma (MM).

2012 ◽  
Vol 30 (15_suppl) ◽  
pp. e18554-e18554
Author(s):  
Justin M. Markow ◽  
Amishi Desai ◽  
Harry Staszewski
Keyword(s):  
Limited Data ◽  
Mri Findings ◽  
Data Set ◽  
Exact Test ◽  
Asymptomatic Patients ◽  
Spinal Mri ◽  
Baseline Characteristics ◽  
Initial Imaging ◽  
The Relationship ◽  
Risk Ratios

e18554 Background: Current recommendations for the evaluation of MM include a skeletal survey (SS) and possibly an MRI. The literature documents a discrepancy in the detection of important skeletal lesions between these two techniques. There is limited data on the relationship between symptoms and spinal MRI findings. We analyzed the correlation of symptoms with an abnormal MRI in our patients. Methods: We analyzed 66 unselected,retrospectively identified patients with MM using lab values, ISS scores, the initial SS, and MRI. Skeletal symptoms, interval between studies, discordance between imaging by modality, and interventions were also tabulated. Risk ratios (RR) were calculated for the probability of radiologic abnormalities based on symptoms. Fischer's exact test was applied. Results: The baseline characteristics by age, gender, race, ISS score, and other lab values were similar between groups. 53% (35/66) of patients had an MRI at diagnosis. 51.4% (18/35) of these had different findings from the SS (95% CI, 35.6% - 67.0%). 30.8% (8/26) of patients with an MRI abnormality were asymptomatic or had symptoms in a different location than seen on MRI (95% CI, 16.3% - 50.1%). 15.4% (4/26) of these patients were asymptomatic at presentation (95% CI, 5.5% - 34.2%). (RR) for patients with any reported symptom and abnormal MRI finding is 2.6 (95% CI, 1.1 - 5.6, p< 0.01), while the RR for a symptom corresponding to its anatomic area on MRI is 1.3 (95%CI .8 - 2.1, p = 0.23). Conclusions: 30% of our patients with an abnormal MRI were asymptomatic or reported symptoms in a different area. The RR for an abnormal MRI result in patients with any symptom was significant, but the symptomatic area did not correlate with the anatomic MRI abnormality. This suggests that a significant amount of disease is missed because imaging may be confined to the symptomatic area and asymptomatic patients are less likely to have an MRI. Within this limited data set, there appears to be an advantage to performing routine initial MRI

Optimum plant population densities for lupin (Lupinus angustifolius L.) in the wheatbelt of Western Australia

1994 ◽  
Vol 34 (4) ◽  
pp. 491 ◽  
Author(s):  
RJ French ◽  
K McCarthy ◽  
WL Smart
Keyword(s):  
Western Australia ◽  
Plant Population ◽  
Lupinus Angustifolius ◽  
Yield Potential ◽  
Asymptotic Model ◽  
Population Densities ◽  
Data Set ◽  
Optimum Density ◽  
Wide Range ◽  
The Relationship

Lupin (Lupinus angustifolius L.) seed yields at various plant population densities were studied in 33 separate experiments throughout the wheatbelt of Western Australia between 1987 and 1990. The experiments were designed to test the hypotheses that optimum plant population densities for lupins vary between environments and between cultivars. Another objective was the development of a framework for sowing rate recommendations from a large data set derived from sowing rate experiments. Two types of equation were fitted to each data set by nonlinear regression: one described an asymptotic response, the other a response where yield reached a maximum but declined at higher densities. The second type of equation was used to describe a data set if the residual mean square was significantly lower than for the asymptotic equation. In all, 122 individual responses were fitted, of these only 13 were not adequately described by the asymptotic model. Optimum density was chosen according to an economic criterion (when marginal revenue from an increase in plant population density equalled marginal cost). This was equivalent to choosing the point where the slope of the response curve was 0.004 t.m2/ha.plant (equivalent to 0.4 g/plant). Optimum density ranged from 14 to 138 plants/m2 and was linearly related to yield potential, which we defined as either the asymptotic yield value, or the maximum yield for responses that did not approach an asymptote. Yield potential ranged from 0.13 to 4.1 t/ha. The relationship between optimum density and yield potential was the same for cvv. Danja, Gungurru, and Yorrel, and for a reduced branching breeding line (75A/329). It was also the same on soils classified as good or poor for lupins. We suggest that the relationship between optimum density and yield potential will be useful in determining target plant densities for lupins under a wide range of conditions in Western Australia, and that the techniques should prove useful in producing recommendations from density experiments in other agricultural regions.

Determinants of species abundance in the Quaternary vertebrate fossil record

Paleobiology ◽  
2011 ◽  
Vol 37 (3) ◽  
pp. 537-546 ◽  
Author(s):  
Samuel T. Turvey ◽  
Tim M. Blackburn
Keyword(s):  
Body Mass ◽  
Species Abundance ◽  
Ecological Factors ◽  
General Applicability ◽  
Data Set ◽  
Terrestrial Vertebrate ◽  
Wide Range ◽  
Holocene Record ◽  
Independent Calibration ◽  
The Relationship

Species abundance data are of vital importance in paleontology, but fossil accumulations invariably represent a biased subset of original source communities. Efforts to quantify taphonomic biases are typically prevented by a lack of independent data on the ecological composition of prehistoric faunas. However, analysis of the continental Holocene record can provide a rare opportunity for independent calibration of fossil abundance patterns. We analyzed a comprehensive data set available for the Holocene avifauna of Sweden to investigate the relationship between species abundance in the recent fossil and zooarchaeological records and in prehistoric source communities, and to characterize the importance of different ecological factors in determining terrestrial vertebrate fossil abundances. The number of assemblages in which species occurred was compared with modern-day species abundance, annual residence, body mass, and ecological realm. Modern-day abundance is only one of several significant predictors of fossil abundance; the strongest predictor is body mass, and Holocene species abundance can be interpreted as a measure of species abundance in source communities for a given size class only. Our study represents one of the only direct attempts to quantify species abundance biases between fossil faunas and source communities, and has general applicability for a wide range of terrestrial vertebrate faunas.

scholarly journals The relationship between self-employment and unemployment in the long-run

2016 ◽  
Vol 43 (3) ◽  
pp. 358-379 ◽  
Author(s):  
George Saridakis ◽  
Miguel Angel Mendoza ◽  
Rebeca I. Muñoz Torres ◽  
Jane Glover
Keyword(s):  
Design Methodology ◽  
Structural Breaks ◽  
Panel Cointegration ◽  
Data Set ◽  
Content Type ◽  
Self Employment ◽  
Long Run ◽  
Wide Range ◽  
Short Run ◽  
The Relationship

Purpose – Although a lot of research has been done on the link between self-employment and unemployment, often focusing on the short-run of the relationship, the long-run association between the two variables has not received adequate attention. The paper aims to discuss these issues. Design/methodology/approach – In this paper the authors examine the long-run relationship between self-employment and unemployment using panel cointegration methods allowing for structural breaks and covering a wide range of European OECD countries using the COMPENDIA data set over the period 1990-2011. Findings – The findings indicate that a long-run relationship between self-employment and unemployment exist in the panel, but the cointegrating coefficients are unstable. Originality/value – The estimates finds positive and statistically significant long-run association between self-employment and unemployment exists for more than 50 per cent of the countries included in the sample after the break. For the rest of the countries the authors find either negative or statistically insignificant association.

scholarly journals Fractal Dimension Estimation in Diagnosing Alzheimer’s Disease

10.14311/1785 ◽  
2013 ◽  
Vol 53 (2) ◽  
Author(s):  
Václav Hubata-Vacek ◽  
Jaromír Kukal ◽  
Robert Rusina ◽  
Marie Buncová
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Fractal Dimension ◽  
Taylor Series ◽  
Fractal Dimensions ◽  
Limited Data ◽  
Data Set ◽  
Brain Scans ◽  
Definition Of ◽  
The Relationship

Estimated entropies from a limited data set are always biased. Consequently, it is not a trivial task to calculate the entropy in real tasks. In this paper, we used a generalized definition of entropy to evaluate the Hartley, Shannon, and Collision entropies. Moreover, we applied the Miller and Harris estimations of Shannon entropy, which are well known bias approaches based on Taylor series. Finally, these estimates were improved by Bayesian estimation of individual probabilities. These methods were tested and used for recognizing Alzheimer’s disease, using the relationship between entropy and the fractal dimension to obtain fractal dimensions of 3D brain scans.

The Problem of Identifying and Modeling the Relationship between Monetary Factor and Inflation in the Russian Economy

2008 ◽  
pp. 61-76
Author(s):  
A. Porshakov ◽  
A. Ponomarenko
Keyword(s):  
Money Supply ◽  
Money Demand ◽  
Russian Economy ◽  
Long Run ◽  
Complex Approach ◽  
Wide Range ◽  
Long Time ◽  
The Relationship ◽  
Supply Side Factors

The role of monetary factor in generating inflationary processes in Russia has stimulated various debates in social and scientific circles for a relatively long time. The authors show that identification of the specificity of relationship between money and inflation requires a complex approach based on statistical modeling and involving a wide range of indicators relevant for the price changes in the economy. As a result a model of inflation for Russia implying the decomposition of inflation dynamics into demand-side and supply-side factors is suggested. The main conclusion drawn is that during the recent years the volume of inflationary pressures in the Russian economy has been determined by the deviation of money supply from money demand, rather than by money supply alone. At the same time, monetary factor has a long-run spread over time impact on inflation.

Structure Guided Molecular Docking Assisted Alignment Dependent 3DQSAR Study on Steroidal Aromatase Inhibitors (SAIs) as Anti-breast Cancer Agents

2019 ◽  
Vol 16 (7) ◽  
pp. 808-817 ◽  
Author(s):  
Laxmi Banjare ◽  
Sant Kumar Verma ◽  
Akhlesh Kumar Jain ◽  
Suresh Thareja
Keyword(s):  
Breast Cancer ◽  
Molecular Docking ◽  
Aromatase Inhibitors ◽  
Direct Synthesis ◽  
3D Qsar ◽  
Chemotherapeutic Agents ◽  
Modeling Tools ◽  
Data Set ◽  
Wide Range ◽  
Steroidal Aromatase Inhibitors

Background: In spite of the availability of various treatment approaches including surgery, radiotherapy, and hormonal therapy, the steroidal aromatase inhibitors (SAIs) play a significant role as chemotherapeutic agents for the treatment of estrogen-dependent breast cancer with the benefit of reduced risk of recurrence. However, due to greater toxicity and side effects associated with currently available anti-breast cancer agents, there is emergent requirement to develop target-specific AIs with safer anti-breast cancer profile. Methods: It is challenging task to design target-specific and less toxic SAIs, though the molecular modeling tools viz. molecular docking simulations and QSAR have been continuing for more than two decades for the fast and efficient designing of novel, selective, potent and safe molecules against various biological targets to fight the number of dreaded diseases/disorders. In order to design novel and selective SAIs, structure guided molecular docking assisted alignment dependent 3D-QSAR studies was performed on a data set comprises of 22 molecules bearing steroidal scaffold with wide range of aromatase inhibitory activity. Results: 3D-QSAR model developed using molecular weighted (MW) extent alignment approach showed good statistical quality and predictive ability when compared to model developed using moments of inertia (MI) alignment approach. Conclusion: The explored binding interactions and generated pharmacophoric features (steric and electrostatic) of steroidal molecules could be exploited for further design, direct synthesis and development of new potential safer SAIs, that can be effective to reduce the mortality and morbidity associated with breast cancer.

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