Estimating Foreign Exchange Reserve Adequacy
Directory of Open Access Journals (Sweden)
Abdul Hakim
2013-04-01
Full Text Available Accumulating foreign exchange reserves, despite their cost and their impacts on other macroeconomics variables, provides some benefits. This paper models such foreign exchange reserves. To measure the adequacy of foreign exchange reserves for import, it uses total reserves-to-import ratio (TRM. The chosen independent variables are gross domestic product growth, exchange rates, opportunity cost, and a dummy variable separating the pre and post 1997 Asian financial crisis. To estimate the risky TRM value, this paper uses conditional Value-at-Risk (VaR, with the help of Glosten-Jagannathan-Runkle (GJR model to estimate the conditional volatility. The results suggest that all independent variables significantly influence TRM. They also suggest that the short and long run volatilities are evident, with the additional evidence of asymmetric effects of negative and positive past shocks. The VaR, which are calculated assuming both normal and t distributions, provide similar results, namely violations in 2005 and 2008.
Reserve growth during financial volatility in a technologically challenging world
Klett, Timothy R.; Gautier, Donald L.
2010-01-01
Reserve growth (growth-to-known) is the addition of oil and gas quantities to reported proved or proved-plus-probable reserves in discovered fields. The amount of reserve growth fluctuates through time with prevailing economic and technological conditions. Most reserve additions are the result of investment in field operations and in development technology. These investments can be justified by higher prices of oil and gas, the desire to maintain cash flow, and by greater recovery efficiency in well established fields. The price/cost ratio affects decisions for field abandonment and (or) implementation of improved recovery methods. Although small- to medium-size fields might show higher percentages of reserve growth, a relatively few giant fields contribute most volumetric reserve growth, indicating that companies may prefer to invest in existing fields with low geologic and production risk and an established infrastructure in order to increase their price/cost relationship. Whereas many previous estimates of reserve growth were based on past trends of reported reserves, future reserve growth is expected to be greatly affected by financial volatility and fluctuating economic and technological conditions.
Estimation of gas reserves in North America
International Nuclear Information System (INIS)
Laherrere, J.
2001-01-01
If the oil market is global, the gas market is divided into three zones: North America, Europe and Asia. The official forecast of the future demand of North America gas is optimist as it is based on estimates of resources which are ten times those of the proved reserves. The poor practice (SEC rules) of proved reserves (when the rest of the world uses proven+probable) leads to a constant revision and a growth of the past discoveries, showing well a wrong evaluation. The official databases are then very poor, even those of the US federal domain, which have to be public. The study of the technical data of reserves of US, Canada and Mexico leads to a more pessimistic estimation of the ultimate reserves and then to the future local supply. In the Gulf of Mexico (the main hope), the production of natural gas in shallow water decline and the discoveries in the deep-water are mainly oil. The non-conventional gas seems to level. But the future demand is also too optimistic, based on cheap price and on a steady growth. However the local gas supply will be likely insufficient, and the demand will need imported liquefied natural gas. (author)
Reserve growth in German oilfields; Reservenwachstum in deutschen Erdoelfeldern
Energy Technology Data Exchange (ETDEWEB)
Schwietzer, Curt-Albert [RWE Dea AG, Hamburg (Germany)
2013-07-15
In the English language use, the term ''Reserve Growth'' describes the fact that in most cases at the start of a field development the estimated ultimate recovery of reserves (EUR) is smaller than it will turn out later by production history. Although this phenomenon of reserve growth gives hints for new reserves in mature hydrocarbon provinces, it has hardly been investigated. In the few existing studies about this issue it is shown that reserve growth is, in the majority of cases, based on factors like the application of improved methods to increase the recovery factor as well as on optimization of the reservoir development by precise modeling and simulation as well as on changing of the reserve classification. Different combinations of these factors affect the changes of reserves during the life of the reservoir. This study investigates the reserve trend of 35 German oilfields over the last 40 to 50 years. Most of them register reserve growth; in some cases even a factor > 10 was achieved. On average, this reserve growth factor can be calculated as 3. A similar study about US American onshore oilfields was carried out for the first time by Arrington; this was, at a later time, revised by the USGS. In the article, Mahendra K. Verma developed the ''Growth Function'' by regression. The ''Growth Function'' describes the changes of proved reserves during the life of an oil reservoir. It indicates that ten years after production start, the reserves increased by three times, whereas the largest proportion of this increase occurred in the first three years. During the next 30 years, the reserves growth factor increased by up to 5.3; at the point of 95 years of production it accumulated to 6.9. In the case of the analysed German oilfields, the reserve growth behaviour was similar. Corresponding to the ''Growth Function'' after 40 years of production, it achieved a factor of 5 and reached a
Reserve Growth in Oil Fields of West Siberian Basin, Russia
Verma, Mahendra K.; Ulmishek, Gregory F.
2006-01-01
Although reserve (or field) growth has proven to be an important factor contributing to new reserves in mature petroleum basins, it is still a poorly understood phenomenon. Limited studies show that the magnitude of reserve growth is controlled by several major factors, including (1) the reserve booking and reporting requirements in each country, (2) improvements in reservoir characterization and simulation, (3) application of enhanced oil recovery techniques, and (4) the discovery of new and extensions of known pools in discovered fields. Various combinations of these factors can affect the estimates of proven reserves in particular fields and may dictate repeated estimations of reserves during a field's life. This study explores the reserve growth in the 42 largest oil fields in the West Siberian Basin, which contain about 55 percent of the basin's total oil reserves. The West Siberian Basin occupies a vast swampy plain between the Ural Mountains and the Yenisey River, and extends offshore into the Kara Sea; it is the richest petroleum province in Russia. About 600 oil and gas fields with original reserves of 144 billion barrels of oil (BBO) and more than 1,200 trillion cubic feet of gas (TCFG) have been discovered. The principal oil reserves and most of the oil fields are in the southern half of the basin, whereas the northern half contains mainly gas reserves. Sedimentary strata in the basin consist of Upper Triassic through Tertiary clastic rocks. Most oil is produced from Neocomian (Lower Cretaceous) marine to deltaic sandstone reservoirs, although substantial oil reserves are also in the marine Upper Jurassic and continental to paralic Lower to Middle Jurassic sequences. The majority of oil fields are in structural traps, which are gentle, platform-type anticlines with closures ranging from several tens of meters to as much as 150 meters (490 feet). Fields producing from stratigraphic traps are generally smaller except for the giant Talin field which
Reserve growth of the world's giant oil fields
Klett, T.R.; Schmoker, J.W.
2005-01-01
Analysis of estimated total recoverable oil volume (field size) of 186 well-known giant oil fields of the world (>0.5 billion bbl of oil, discovered prior to 1981), exclusive of the United States and Canada, demonstrates general increases in field sizes through time. Field sizes were analyzed as a group and within subgroups of the Organization of Petroleum Exporting Countries (OPEC) and non-OPEC countries. From 1981 through 1996, the estimated volume of oil in the 186 fields for which adequate data were available increased from 617 billion to 777 billion bbl of oil (26%). Processes other than new field discoveries added an estimated 160 billion bbl of oil to known reserves in this subset of the world's oil fields. Although methods for estimating field sizes vary among countries, estimated sizes of the giant oil fields of the world increased, probably for many of the same reasons that estimated sizes of oil fields in the United States increased over the same time period. Estimated volumes in OPEC fields increased from a total of 550 billion to 668 billion bbl of oil and volumes in non-OPEC fields increased from 67 billion to 109 billion bbl of oil. In terms of percent change, non-OPEC field sizes increased more than OPEC field sizes (63% versus 22%). The changes in estimated total recoverable oil volumes that occurred within three 5-year increments between 1981 and 1996 were all positive. Between 1981 and 1986, the increase in estimated total recoverable oil volume within the 186 giant oil fields was 11 billion bbl of oil; between 1986 and 1991, the increase was 120 billion bbl of oil; and between 1991 and 1996, the increase was 29 billion bbl of oil. Fields in both OPEC and non-OPEC countries followed trends of substantial reserve growth.
United States geological survey's reserve-growth models and their implementation
Klett, T.R.
2005-01-01
The USGS has developed several mathematical models to forecast reserve growth of fields both in the United States (U.S.) and the world. The models are based on historical reserve growth patterns of fields in the U.S. The patterns of past reserve growth are extrapolated to forecast future reserve growth. Changes of individual field sizes through time are extremely variable, therefore, the reserve growth models take on a statistical approach whereby volumetric changes for populations of fields are used in the models. Field age serves as a measure of the field-development effort that is applied to promote reserve growth. At the time of the USGS World Petroleum Assessment 2000, a reserve growth model for discovered fields of the world was not available. Reserve growth forecasts, therefore, were made based on a model of historical reserve growth of fields of the U.S. To test the feasibility of such an application, reserve growth forecasts were made of 186 giant oil fields of the world (excluding the U.S. and Canada). In addition, forecasts were made for these giant oil fields subdivided into those located in and outside of Organization of Petroleum Exporting Countries (OPEC). The model provided a reserve-growth forecast that closely matched the actual reserve growth that occurred from 1981 through 1996 for the 186 fields as a whole, as well as for both OPEC and non-OPEC subdivisions, despite the differences in reserves definition among the fields of the U.S. and the rest of the world. ?? 2005 International Association for Mathematical Geology.
Reserve growth in oil pools of Alberta : model and forecast
Energy Technology Data Exchange (ETDEWEB)
Verma, M.; Cook, T. [United States Geological Survey, Denver, CO (United States). Central Region
2010-09-15
This paper presented a reserve growth study that was conducted on oil pools in Alberta, Canada. Historical oil reserve data were evaluated to assess the potential for future reserve growth in both pools and fields, and reserve growth models and functions were developed to better forecast hydrocarbon volumes. The study also considered the sensitivity of reserve growth to such factors as pool size, porosity, and oil gravity. From 1960 to 2005, the reported known recoverable oil in Alberta, excluding the Athabasca oil sands and including only pools with adequate data, increased from 4.2 to 13.9 billion barrels of oil (BBO). New discoveries contributed 3.7 BBO and reserve growth added 6 BBO. Most reserve growth occurred in pools with more than 125,000 barrels of oil. Light-oil pools account for most of the total known oil volume and consequently showed the lowest growth. Pools with greater than 30 percent porosity grew more than pools with lower porosity reservoirs. Oil field growth was found to be almost twice that of pool growth, possibly because the analysis evaluated fields with two or more pools discovered in different years. The growth in oil volumes in Alberta pools is projected to be about 454 million barrels of oil in the period from 2006 to 2010. Over a 25-year period, the cumulative reserve growth in Alberta oil pools was substantially lower than other major petroleum-producing regions, but the growth at the field level compares well. 8 refs., 2 tabs., 9 figs.
Estimating the optimal growth-maximising public debt threshold for ...
African Journals Online (AJOL)
kirstam
Dr N. Mupunga is at the Reserve Bank of Zimbabwe, and Prof. P. le Roux is in the Department of Economics, Nelson ..... negative correlation between debt and growth. Moreover the estimated endogenous ..... GDP ratio calibrated by the IMF and World Bank (2012: 25) for low-income countries rated weak in terms of country ...
Natural gas reserve growth in Canada
Energy Technology Data Exchange (ETDEWEB)
Woronuk, R. [Canadian Gas Potential Committee, Calgary, AB (Canada)]|[GasEnergy Strategies Inc., Calgary, AB (Canada)
2003-07-01
An appreciation study of a natural gas reservoir is a component of assessing its ultimate reserve potential. The Canadian Gas Potential Committee (CGPC) defines appreciation as the change in a reserve estimate from a previously booked pool or basin. Basins cannot appreciate through the addition of new pools. Ultimate potential includes all of the following: cumulative production; remaining discovered reserves; adjustments to remaining discovered reserves; and, full appreciated undiscovered reserves. This presentation outlined the procedures used by the CGPC in its appreciation studies. It also reviewed data supplier issues, regulatory practices, and booking issues. A series of graphs were also included depicting pools discovered in 1993 and the average pool gas in place. Reservoir loss from 1993 to 1998 was attributed to the fact that enhanced recovery technology cannot keep pace with the degradation in pool quality. It was noted that beyond 1998, significant increases in gas prices should increase recovery factors. Special studies by the Alberta Energy and Utilities Board have included the depreciation of unconnected gas pools and the appreciation of sheet sands. The challenge of tracking pool appreciation was discussed with reference to estimating new pool discoveries in established fields. 2 tabs., 6 figs.
Methods for the estimation of uranium ore reserves
International Nuclear Information System (INIS)
1985-01-01
The Manual is designed mainly to provide assistance in uranium ore reserve estimation methods to mining engineers and geologists with limited experience in estimating reserves, especially to those working in developing countries. This Manual deals with the general principles of evaluation of metalliferous deposits but also takes into account the radioactivity of uranium ores. The methods presented have been generally accepted in the international uranium industry
Ore reserve estimation of uranium deposit Zirovski vrh
International Nuclear Information System (INIS)
Lukacs, E.
1979-01-01
The uranium ore deposit Zirovski vrh is in the Permian sediments of Northwest Yugoslavia. Lenticular bodies occur at several stratiform levels in grey, medium-grained sandstone. The ore deposit will be mined entirely by underground methods. It is possible to define three stages of deposit evaluation requiring different densities of exploration effort: preliminary evaluation of in situ ore reserves; evaluation of mineable ore reserves; evaluation of production capability and mine planning. The drilling density increases markedly with each succeeding stage. The optimal drilling density for all three stages of evaluation should be determined, but there is some concern that too close spaced drilling would considerably increase the exploration costs without a corresponding increase in effectiveness. On the other hand, too sparsely spaced drilling may result in some difficulties in following the ore in mining. The paper treats the problem of the density of drilling for evaluation of mineable ore reserves compared to that required for mine planning and mine production capability. The purpose of investigation of mineral raw materials is to define economic deposits (ore bodies). To evaluate the deposit economically an accurate reserve estimate is required. If it is accordingly established that such an estimate is within the degree of admissible error, the purpose of the exploration is satisfied. However, the problem as to whether the drilling grid is sufficiently dense remains, because the majority of estimates of ore reserves do not provide a measure of the reliability of the estimate. (author)
Improvements to the quality of the estimates of US uranium reserves
International Nuclear Information System (INIS)
Nikodem, Z.D.
1998-01-01
Extensive work has been done in the United States in the estimation of uranium reserves. The government's role in uranium raw materials shifted from support of military programmes to assessing the supply available for commercial power generation. A comprehensive system evolved in which government staff estimated reserves for each property over a range of cost levels using standardized estimation methodology and criteria. The programme was assigned to the Energy Information Administration (EIA) of the Department of Energy in 1983 which has the responsibility for reporting on energy resources. As uranium supply had increased and demand had decreased, there was less concern about the adequacy of resources. In this situation, and with reduced staffing levels, the EIA adopted a two part interim approach to preparing reserve estimates. One used questionnaires to obtain uranium company estimates of their economic and subeconomic reserves, with company determined economic criteria. A second approach modified the earlier detailed government property estimates to account for production. The EIA developed a new system with the assistance of consultants and the uranium industry. The goal of the new system is to produce one set of estimates at various cost categories for each property based on a rigorous adherence to EIA criteria. Initial information is gathered from the industry through a revised annual questionnaire. Company estimates that conform to EIA standards are incorporated into the EIA reserve data base. Additional information is gathered for those estimates requiring clarification, primarily through detailed technical conferences with company staff. The EIA has the capability to prepare independent reserve estimates from basic drill hole data when required. Uranium reserves estimated for 1990 by the EIA include the initial results from the new methodology. The cooperation and support of the uranium industry have been excellent. Detailed evaluation of properties is
EMPIRICAL EVIDENCE ON DYNAMICS OF CREDIT GROWTH AND FOREIGN RESERVE
Directory of Open Access Journals (Sweden)
Satrugan Sinah
2017-09-01
Full Text Available The paper presents a model for looking into the nature of change in foreign reserve from movements in domestic credit. This model is relevant to foreign reserve targeting, small and open economies. The model denotes that measures undertaken by central banks to constraint domestic credit growth with the view of controlling capital outflows will also be detrimental to foreign reserves level. The empirical studies with application of Fourier Transformation technique have been used to build a model, which shows that growth in domestic credit is more biased towards positive swings in foreign reserves, rather than being unfavorable. The small and open economies, particularly, the Pacific Island nations, have the right set up for application of this model to safeguard foreign reserves level.
A Bootstrap Approach to Computing Uncertainty in Inferred Oil and Gas Reserve Estimates
International Nuclear Information System (INIS)
Attanasi, Emil D.; Coburn, Timothy C.
2004-01-01
This study develops confidence intervals for estimates of inferred oil and gas reserves based on bootstrap procedures. Inferred reserves are expected additions to proved reserves in previously discovered conventional oil and gas fields. Estimates of inferred reserves accounted for 65% of the total oil and 34% of the total gas assessed in the U.S. Geological Survey's 1995 National Assessment of oil and gas in US onshore and State offshore areas. When the same computational methods used in the 1995 Assessment are applied to more recent data, the 80-year (from 1997 through 2076) inferred reserve estimates for pre-1997 discoveries located in the lower 48 onshore and state offshore areas amounted to a total of 39.7 billion barrels of oil (BBO) and 293 trillion cubic feet (TCF) of gas. The 90% confidence interval about the oil estimate derived from the bootstrap approach is 22.4 BBO to 69.5 BBO. The comparable 90% confidence interval for the inferred gas reserve estimate is 217 TCF to 413 TCF. The 90% confidence interval describes the uncertainty that should be attached to the estimates. It also provides a basis for developing scenarios to explore the implications for energy policy analysis
Population Growth and Sprawl on the Pine Ridge Indian Reservation, South Dakota
Campbell, R. L.
2006-05-01
The most important impact on global land cover is human use and development. With the recent population growth occurring on the reservations in South Dakota, especially Pine Ridge Indian Reservation, the towns and agricultural areas of the reservation are undergoing a change. Although urban sprawl certainly is not a consideration on the reservations, the population explosion currently underway has seen a subsequent increase in rural sprawl. In this case, rural sprawl is defined as exponential population growth and geographic expansion of remote reservation communities. Using satellite imagery and software to render these images is a cost effective way to investigate this growth. Also, using remotely sensed data and a GIS (geographic information system) package can address different issues that concern people and communities in and around the Pine Ridge area. The objective of my project is to observe land use change on the Pine Ridge Indian reservation using Geographic Information Systems such as; ARCGis 9, ENVI, and Multispec, along with Landsat 4, 5, and 7 imagery over the past 20 years.
Energy Technology Data Exchange (ETDEWEB)
Hamilton, D.S.; Raeuchle, S.K.; Holtz, M.H. [Bureau of Economic Geology, Austin, TX (United States)] [and others
1997-08-01
We applied an integrated geologic, geophysical, and engineering approach devised to identify heterogeneities in the subsurface that might lead to reserve growth opportunities in our analysis of the Oficina Formation at Budare field, Venezuela. The approach involves 4 key steps: (1) Determine geologic reservoir architecture; (2) Investigate trends in reservoir fluid flow; (3) Integrate fluid flow trends with reservoir architecture; and (4) Estimate original oil-in-place, residual oil saturation, and remaining mobile oil, to identify opportunities for reserve growth. There are three main oil-producing reservoirs in the Oficina Formation that were deposited in a bed-load fluvial system, an incised valley-fill, and a barrier-strandplain system. Reservoir continuity is complex because, in addition to lateral facies variability, the major Oficina depositional systems were internally subdivided by high-frequency stratigraphic surfaces. These surfaces define times of intermittent lacustrine and marine flooding events that punctuated the fluvial and marginal marine sedimentation, respectively. Syn and post depositional faulting further disrupted reservoir continuity. Trends in fluid flow established from initial fluid levels, response to recompletion workovers, and pressure depletion data demonstrated barriers to lateral and vertical fluid flow caused by a combination of reservoir facies pinchout, flooding shale markers, and the faults. Considerable reserve growth potential exists at Budare field because the reservoir units are highly compartment by the depositional heterogeneity and structural complexity. Numerous reserve growth opportunities were identified in attics updip of existing production, in untapped or incompletely drained compartments, and in field extensions.
Ore reserve estimation: a summary of principles and methods
International Nuclear Information System (INIS)
Marques, J.P.M.
1985-01-01
The mining industry has experienced substantial improvements with the increasing utilization of computerized and electronic devices throughout the last few years. In the ore reserve estimation field the main methods have undergone recent advances in order to improve their overall efficiency. This paper presents the three main groups of ore reserve estimation methods presently used worldwide: Conventional, Statistical and Geostatistical, and elaborates a detaited description and comparative analysis of each. The Conventional Methods are the oldest, less complex and most employed ones. The Geostatistical Methods are the most recent precise and more complex ones. The Statistical Methods are intermediate to the others in complexity, diffusion and chronological order. (D.J.M.) [pt
On the estimation of the volatility-growth link
DEFF Research Database (Denmark)
Launov, Andrey; Posch, Olaf; Wälde, Klaus
It is common practice to estimate the volatility-growth link by specifying a standard growth equation such that the variance of the error term appears as an explanatory variable in this growth equation. The variance in turn is modelled by a second equation. Hardly any of existing applications...... of this framework includes exogenous controls in this second variance equation. Our theoretical …ndings suggest that the absence of relevant explanatory variables in the variance equation leads to a biased and inconsistent estimate of the volatility-growth link. Our simulations show that this effect is large. Once...... the appropriate controls are included in the variance equation consistency is restored. In short, we suggest that the variance equation must include relevant control variables to estimate the volatility-growth link....
Error estimation in plant growth analysis
Directory of Open Access Journals (Sweden)
Andrzej Gregorczyk
2014-01-01
Full Text Available The scheme is presented for calculation of errors of dry matter values which occur during approximation of data with growth curves, determined by the analytical method (logistic function and by the numerical method (Richards function. Further formulae are shown, which describe absolute errors of growth characteristics: Growth rate (GR, Relative growth rate (RGR, Unit leaf rate (ULR and Leaf area ratio (LAR. Calculation examples concerning the growth course of oats and maize plants are given. The critical analysis of the estimation of obtained results has been done. The purposefulness of joint application of statistical methods and error calculus in plant growth analysis has been ascertained.
A test and re-estimation of Taylor's empirical capacity-reserve relationship
Long, K.R.
2009-01-01
In 1977, Taylor proposed a constant elasticity model relating capacity choice in mines to reserves. A test of this model using a very large (n = 1,195) dataset confirms its validity but obtains significantly different estimated values for the model coefficients. Capacity is somewhat inelastic with respect to reserves, with an elasticity of 0.65 estimated for open-pit plus block-cave underground mines and 0.56 for all other underground mines. These new estimates should be useful for capacity determinations as scoping studies and as a starting point for feasibility studies. The results are robust over a wide range of deposit types, deposit sizes, and time, consistent with physical constraints on mine capacity that are largely independent of technology. ?? 2009 International Association for Mathematical Geology.
Estimating the optimal growth-maximising public debt threshold for ...
African Journals Online (AJOL)
This paper attempts to estimate an optimal growth-maximising public debt threshold for Zimbabwe. The public debt threshold is estimated by assessing the relationship between public debt and economic growth. The analysis is undertaken to determine the tipping point beyond which increases in public debt adversely affect ...
Incremental natural gas resources through infield reserve growth/secondary natural gas recovery
Energy Technology Data Exchange (ETDEWEB)
Finley, R.J.; Levey, R.A.; Hardage, B.A.
1993-12-31
The primary objective of the Infield Reserve Growth/Secondary Natural Gas Recovery (SGR) project is to develop, test, and verify technologies and methodologies with near- to midterm potential for maximizing the recovery of natural gasfrom conventional reservoirs in known fields. Additional technical and technology transfer objectives of the SGR project include: To establish how depositional and diagenetic heterogeneities in reservoirs of conventional permeability cause reservoir compartmentalization and, hence, incomplete recovery of natural gas. To document examples of reserve growth occurrence and potential from fluvial and deltaic sandstones of the Texas gulf coast basin as a natural laboratory for developing concepts and testing applications to find secondary gas. To demonstrate how the integration of geology, reservoir engineering, geophysics, and well log analysis/petrophysics leads to strategic recompletion and well placement opportunities for reserve growth in mature fields. To transfer project results to a wide array of natural gas producers, not just as field case studies, but as conceptual models of how heterogeneities determine natural gas flow units and how to recognize the geologic and engineering clues that operators can use in a cost-effective manner to identify incremental, or secondary, gas.
Energy Technology Data Exchange (ETDEWEB)
Gaudinski, J.B.; Torn, M.S.; Riley, W.J.; Swanston, C.; Trumbore, S.E.; Joslin, J.D.; Majdi, H.; Dawson, T.E.; Hanson, P.J.
2009-02-01
Characterizing the use of carbon (C) reserves in trees is important for understanding regional and global C cycles, stress responses, asynchrony between photosynthetic activity and growth demand, and isotopic exchanges in studies of tree physiology and ecosystem C cycling. Using an inadvertent, whole-ecosystem radiocarbon ({sup 14}C) release in a temperate deciduous oak forest and numerical modeling, we estimated that the mean age of stored C used to grow both leaf buds and new roots is 0.7 years and about 55% of new-root growth annually comes from stored C. Therefore, the calculated mean age of C used to grow new-root tissue is {approx}0.4 years. In short, new roots contain a lot of stored C but it is young in age. Additionally, the type of structure used to model stored C input is important. Model structures that did not include storage, or that assumed stored and new C mixed well (within root or shoot tissues) before being used for root growth, did not fit the data nearly as well as when a distinct storage pool was used. Consistent with these whole-ecosystem labeling results, the mean age of C in new-root tissues determined using 'bomb-{sup 14}C' in three additional forest sites in North America and Europe (one deciduous, two coniferous) was less than 1-2 years. The effect of stored reserves on estimated ages of fine roots is unlikely to be large in most natural abundance isotope studies. However, models of root C dynamics should take stored reserves into account, particularly for pulse-labeling studies and fast-cycling roots (<1 years).
Weed Growth Stage Estimator Using Deep Convolutional Neural Networks
DEFF Research Database (Denmark)
Teimouri, Nima; Dyrmann, Mads; Nielsen, Per Rydahl
2018-01-01
This study outlines a new method of automatically estimating weed species and growth stages (from cotyledon until eight leaves are visible) of in situ images covering 18 weed species or families. Images of weeds growing within a variety of crops were gathered across variable environmental conditi...... in estimating the number of leaves and 96% accuracy when accepting a deviation of two leaves. These results show that this new method of using deep convolutional neural networks has a relatively high ability to estimate early growth stages across a wide variety of weed species....
Brain reserve and cognitive reserve protect against cognitive decline over 4.5 years in MS.
Sumowski, James F; Rocca, Maria A; Leavitt, Victoria M; Dackovic, Jelena; Mesaros, Sarlota; Drulovic, Jelena; DeLuca, John; Filippi, Massimo
2014-05-20
Based on the theories of brain reserve and cognitive reserve, we investigated whether larger maximal lifetime brain growth (MLBG) and/or greater lifetime intellectual enrichment protect against cognitive decline over time. Forty patients with multiple sclerosis (MS) underwent baseline and 4.5-year follow-up evaluations of cognitive efficiency (Symbol Digit Modalities Test, Paced Auditory Serial Addition Task) and memory (Selective Reminding Test, Spatial Recall Test). Baseline and follow-up MRIs quantified disease progression: percentage brain volume change (cerebral atrophy), percentage change in T2 lesion volume. MLBG (brain reserve) was estimated with intracranial volume; intellectual enrichment (cognitive reserve) was estimated with vocabulary. We performed repeated-measures analyses of covariance to investigate whether larger MLBG and/or greater intellectual enrichment moderate/attenuate cognitive decline over time, controlling for disease progression. Patients with MS declined in cognitive efficiency and memory (p improve prediction of future cognitive decline in patients with MS. © 2014 American Academy of Neurology.
Growth and reproductive performance of sambar deer in Sabal Forest Reserve of Sarawak, Malaysia.
Dahlan, Ismail; Dawend, Jiwan
2013-10-01
We examined the growth, reproduction, rutting behavior, and health status of sambar deer (Cervus unicolor brookei) in secondary Acacia mangium plantation. The data were collected over 11 years from a breeding herd of 21 stags and 33 hinds in Sabal Forest Reserve, Sarawak, Malaysia. Brody's growth model of the pooled data is Y t = 148.56 (1 - 0.98e(-0.023t)), which estimates that maximum weights of adults are 184 and 115 kg for males and females respectively. Sambar deer are nonseasonal breeders with the breeding peak in February. Although the earliest age at which a female reached sexual maturity was 11 months, the mean age was 23 ± 7 months. Mean age of first fawning was 32 ± 8 months. Mean gestation period was 259 ± 12 days (n = 82). Stags shed antlers mostly between March and July. Velvet hardens at 103 ± 27 days (n = 23), and velvet harvesting is best at 7-9 weeks when antler length is 25-30 cm. Sambar deer are suitable as a farm species in forest plantations and have a vast potential to uplift rural living standards.
Reliability/Cost Evaluation on Power System connected with Wind Power for the Reserve Estimation
DEFF Research Database (Denmark)
Lee, Go-Eun; Cha, Seung-Tae; Shin, Je-Seok
2012-01-01
Wind power is ideally a renewable energy with no fuel cost, but has a risk to reduce reliability of the whole system because of uncertainty of the output. If the reserve of the system is increased, the reliability of the system may be improved. However, the cost would be increased. Therefore...... the reserve needs to be estimated considering the trade-off between reliability and economic aspects. This paper suggests a methodology to estimate the appropriate reserve, when wind power is connected to the power system. As a case study, when wind power is connected to power system of Korea, the effects...
Perry, Russell W.; Plumb, John M.; Huntington, Charles
2015-01-01
To estimate the parameters that govern mass- and temperature-dependent growth, we conducted a meta-analysis of existing growth data from juvenile Chinook Salmon Oncorhynchus tshawytscha that were fed an ad libitum ration of a pelleted diet. Although the growth of juvenile Chinook Salmon has been well studied, research has focused on a single population, a narrow range of fish sizes, or a narrow range of temperatures. Therefore, we incorporated the Ratkowsky model for temperature-dependent growth into an allometric growth model; this model was then fitted to growth data from 11 data sources representing nine populations of juvenile Chinook Salmon. The model fit the growth data well, explaining 98% of the variation in final mass. The estimated allometric mass exponent (b) was 0.338 (SE = 0.025), similar to estimates reported for other salmonids. This estimate of b will be particularly useful for estimating mass-standardized growth rates of juvenile Chinook Salmon. In addition, the lower thermal limit, optimal temperature, and upper thermal limit for growth were estimated to be 1.8°C (SE = 0.63°C), 19.0°C (SE = 0.27°C), and 24.9°C (SE = 0.02°C), respectively. By taking a meta-analytical approach, we were able to provide a growth model that is applicable across populations of juvenile Chinook Salmon receiving an ad libitum ration of a pelleted diet.
Applying a particle filtering technique for canola crop growth stage estimation in Canada
Sinha, Abhijit; Tan, Weikai; Li, Yifeng; McNairn, Heather; Jiao, Xianfeng; Hosseini, Mehdi
2017-10-01
Accurate crop growth stage estimation is important in precision agriculture as it facilitates improved crop management, pest and disease mitigation and resource planning. Earth observation imagery, specifically Synthetic Aperture Radar (SAR) data, can provide field level growth estimates while covering regional scales. In this paper, RADARSAT-2 quad polarization and TerraSAR-X dual polarization SAR data and ground truth growth stage data are used to model the influence of canola growth stages on SAR imagery extracted parameters. The details of the growth stage modeling work are provided, including a) the development of a new crop growth stage indicator that is continuous and suitable as the state variable in the dynamic estimation procedure; b) a selection procedure for SAR polarimetric parameters that is sensitive to both linear and nonlinear dependency between variables; and c) procedures for compensation of SAR polarimetric parameters for different beam modes. The data was collected over three crop growth seasons in Manitoba, Canada, and the growth model provides the foundation of a novel dynamic filtering framework for real-time estimation of canola growth stages using the multi-sensor and multi-mode SAR data. A description of the dynamic filtering framework that uses particle filter as the estimator is also provided in this paper.
Weed Growth Stage Estimator Using Deep Convolutional Neural Networks
DEFF Research Database (Denmark)
Teimouri, Nima; Dyrmann, Mads; Nielsen, Per Rydahl
2018-01-01
conditions with regards to soil types, resolution and light settings. Then, 9649 of these images were used for training the computer, which automatically divided the weeds into nine growth classes. The performance of this proposed convolutional neural network approach was evaluated on a further set of 2516...... in estimating the number of leaves and 96% accuracy when accepting a deviation of two leaves. These results show that this new method of using deep convolutional neural networks has a relatively high ability to estimate early growth stages across a wide variety of weed species....
Che, T D; Wang, C D; Jin, L; Wei, M; Wu, K; Zhang, Y H; Zhang, H M; Li, D S
2015-03-27
Giant panda cubs have a low survival rate during the newborn and early growth stages. However, the growth and developmental parameters of giant panda cubs during the early lactation stage (from birth to 6 months) are not well known. We examined the growth and development of giant panda cubs by the Chapman growth curve model and estimated the heritability of the maximum growth rate at the early lactation stage. We found that 83 giant panda cubs reached their maximum growth rate at approximately 75-120 days after birth. The body weight of cubs at 75 days was 4285.99 g. Furthermore, we estimated that the heritability of the maximum growth rate was moderate (h(2) = 0.38). Our study describes the growth and development of giant panda cubs at the early lactation stage and provides valuable growth benchmarks. We anticipate that our results will be a starting point for more detailed research on increasing the survival rate of giant panda cubs. Feeding programs for giant panda cubs need further improvement.
Parameter Estimates in Differential Equation Models for Population Growth
Winkel, Brian J.
2011-01-01
We estimate the parameters present in several differential equation models of population growth, specifically logistic growth models and two-species competition models. We discuss student-evolved strategies and offer "Mathematica" code for a gradient search approach. We use historical (1930s) data from microbial studies of the Russian biologist,…
Estimating the Broad-Sense Heritability of Early Growth of Cowpea
Xu, Nicole W.; Xu, Shizhong; Ehlers, Jeff
2009-01-01
Cowpea is an important tropical crop. It provides a large proportion of the food resource for the African human population and their livestock. The yield and quality of cowpea have been dramatically improved through traditional breeding strategies for the past few decades. However, reports of heritability estimates for early growth of cowpea are rare. We designed a simple experiment to estimate the broad-sense heritability of early growth. We randomly selected 15 cowpea varieties among a tota...
International Nuclear Information System (INIS)
Banks, H T; Davis, Jimena L; Ernstberger, Stacey L; Hu, Shuhua; Artimovich, Elena; Dhar, Arun K
2009-01-01
We discuss inverse problem results for problems involving the estimation of probability distributions using aggregate data for growth in populations. We begin with a mathematical model describing variability in the early growth process of size-structured shrimp populations and discuss a computational methodology for the design of experiments to validate the model and estimate the growth-rate distributions in shrimp populations. Parameter-estimation findings using experimental data from experiments so designed for shrimp populations cultivated at Advanced BioNutrition Corporation are presented, illustrating the usefulness of mathematical and statistical modeling in understanding the uncertainty in the growth dynamics of such populations
RELATIVECONTRIBUTIONS OF THE NIGERIAN CAPITALMARKETTO THE GROWTH OF EXTERNAL RESERVES (2005-2014
Directory of Open Access Journals (Sweden)
Akaninyene Udo Akpan
2015-01-01
Full Text Available Virtually all aspects of human endeavour entail the use of money either selfgenerated or borrowed. In capital market, the stock in trade is money which couldbe raised through various instruments under well governed rules and regulationscarefully administered and followed by different institutions or market operators.External reserves constitute an integral part of the wealth of the nation such thatthe lack of it brings worry to most nations and can limit the ability of the countryto make foreign currency denominated payments and limits its spending abroad.Hence,countries are induced to hold reserves to allow monetary authorities tointervene in markets to control the exchange rate and inflation. Adequate reservesalso allow the country to borrow from abroad and to hedge against instability anduncertainty of external capital flows.Therefore, the objective of this paper is toaccess the relative contribution of the Nigerian capital market if any to the growthof her external reserve.The methodology used is purely descriptive and narrative and the data used is secondary. The evidence provided in the study based on thestatistical analysis, revealed that the Nigerian capital market can induce thegrowthof external reserve but it has not contributed to the growth of externalreserve in Nigeria. Furthermore, the study recommendedamong otherstheneedfor availability of more investment instruments such as derivatives, futures,swaps, options in the market and theexpansion of the Nigerian capital Market bythe government creating an enabling investable environment that will increaseboth the volume of transactions and number of securities traded in the market.This will improve their ability to mobilize resources and efficiently allocate themto the most productive sectors of the economy hence, contributing its portion tothe growth of her external reserve.
Weed Growth Stage Estimator Using Deep Convolutional Neural Networks.
Teimouri, Nima; Dyrmann, Mads; Nielsen, Per Rydahl; Mathiassen, Solvejg Kopp; Somerville, Gayle J; Jørgensen, Rasmus Nyholm
2018-05-16
This study outlines a new method of automatically estimating weed species and growth stages (from cotyledon until eight leaves are visible) of in situ images covering 18 weed species or families. Images of weeds growing within a variety of crops were gathered across variable environmental conditions with regards to soil types, resolution and light settings. Then, 9649 of these images were used for training the computer, which automatically divided the weeds into nine growth classes. The performance of this proposed convolutional neural network approach was evaluated on a further set of 2516 images, which also varied in term of crop, soil type, image resolution and light conditions. The overall performance of this approach achieved a maximum accuracy of 78% for identifying Polygonum spp. and a minimum accuracy of 46% for blackgrass. In addition, it achieved an average 70% accuracy rate in estimating the number of leaves and 96% accuracy when accepting a deviation of two leaves. These results show that this new method of using deep convolutional neural networks has a relatively high ability to estimate early growth stages across a wide variety of weed species.
Oil, gas field growth projections: Wishful thinking or reality?
Attanasi, E.D.; Mast, R.F.; Root, D.H.
1999-01-01
The observed `field growth' for the period from 1992 through 1996 with the US Geological Survey's (USGS) predicted field growth for the same period are compared. Known field recovery of field size is defined as the sum of past cumulative field production and the field's proved reserves. Proved reserves are estimated quantities of hydrocarbons which geologic and engineering data demonstrate with reasonable certainty to recoverable from known fields under existing economic and operating conditions. Proved reserve estimates calculated with this definition are typically conservative. The modeling approach used by the USGS to characterize `field growth phenomena' is statistical rather that geologic in nature.
Multiple growth-correlated life history traits estimated simultaneously in indivuals
Mollet, F.M.; Ernande, B.; Brunel, T.P.A.; Rijnsdorp, A.D.
2010-01-01
We present a new methodology to estimate rates of energy acquisition, maintenance, reproductive investment and the onset of maturation (four-trait estimation) by fitting an energy allocation model to individual growth trajectories. The accuracy and precision of the method is evaluated on simulated
Financial Security and Optimal Scale of Foreign Exchange Reserve in China
Directory of Open Access Journals (Sweden)
Guangyou Zhou
2018-05-01
Full Text Available The study of how foreign exchange reserves maintain financial security is of vital significance. This paper provides simulations and estimations of the optimal scale of foreign exchange reserves under the background of possible shocks to China’s economy due to the further opening of China’s financial market and the sudden stop of capital inflows. Focused on the perspective of financial security, this article tentatively constructs an optimal scale analysis framework that is based on a utility maximization of the foreign exchange reserve, and selects relevant data to simulate the optimal scale of China’s foreign exchange reserves. The results show that: (1 the main reason for the fast growth of the Chinese foreign exchange reserve scale is the structural trouble of its double international payment surplus, which creates long-term appreciation expectations for the exchange rate that make it difficult for international capital inflows and excess foreign exchange reserves to enter the real economic growth mechanism under the model of China’s export-driven economy growth; (2 the average optimal scale of the foreign exchange reserve in case of the sudden stop of capital inflows was calculated through parameter estimation and numerical simulation to be 13.53% of China’s gross domestic product (GDP between 1994 and 2017; (3 with the function of the foreign exchange reserves changing from meeting basic transaction demands to meeting financial security demands, the effect of the foreign exchange reserve maintaining the state’s financial security is becoming more and more obvious. Therefore, the structure of foreign exchange reserve assets should be optimized in China, and we will give full play to the special role of foreign exchange reserve in safeguarding a country’s financial security.
10 years anniversary of the Poles'e state radioecological reserve (collected articles)
International Nuclear Information System (INIS)
Parfenov, V.I.
1998-01-01
The results of long time investigations of radionuclide contamination dynamics of soils, flora and fauna conducted by research workers of the reserve and National Academy of Sciences of Belarus on the territory of the reserve are offered. The different aspects of plant growth and animal behaviour in new ecological conditions are estimated
Modeling mangrove biomass using remote sensing based age and growth estimates
Lagomasino, D.; Fatoyinbo, T. E.; Feliciano, E. A.; Lee, S. K.; Trettin, C.; Mangora, M.; Rahman, M.
2016-12-01
Mangroves are highly regarded coastal forests because of their ecosystem services and high carbon storage potential. In addition, these forests can develop rapidly in locations where congenial environmental conditions and sediment supply are available. Monitoring the growth and age of developing mangrove forests is crucial for sustainable management and estimating carbon stocks. Combining imagery from radar and optical satellites (e.g., TanDEM-X and Landsat), we can estimate young mangrove growth and age at regional and continental scales. We used TanDEM-X radar interferometry for modeling canopy height in 2013 and Landsat to measure land cover change from 1990 to 2013. Annual NDVI composites were determined for each calendar year between 1990 and 2013. New land areas gained from the transition of water to vegetation were determined by the differences in annual NDVI composites and the reference year 2013. The year of the greatest NDVI difference that met the threshold criteria was used as the initial tree height (0 m). Annual canopy height growth rates were estimated by the duration between land generation times and 2013 canopy height models derived from TanDEM-X and very-high resolution optical data. In this presentation, we compare growth rates and biomass accumulation in mangrove forests at four river deltas; the Zambezi (Mozambique), Rufiji (Tanzania), Ganges (Bangladesh), and Mekong (Vietnam). The spatial patterns of growth rates coincided with characteristic successional paradigms and stream morphology, where the maximum growth rates typically occurred along prograding creek banks. Initial comparisons between height-only and growth-age biomass indicate that the latter tend to overestimate biomass for younger forest stands of similar height. Both the vertical (e.g., canopy height) and horizontal (e.g., expansion) growth rates measured from remote sensing can garner important information regarding mangrove succession and primary productivity. Continued research
Estimating the optimal growth-maximising public debt threshold for ...
African Journals Online (AJOL)
kirstam
Dr N. Mupunga is at the Reserve Bank of Zimbabwe, and Prof. P. le Roux is .... The debt overhang has also led to a huge credit risk premium for both ..... includes gross government debt-to-GDP and economic growth ratios, including almost all ...
Akkermans, Simen; Logist, Filip; Van Impe, Jan F
2018-04-01
When building models to describe the effect of environmental conditions on the microbial growth rate, parameter estimations can be performed either with a one-step method, i.e., directly on the cell density measurements, or in a two-step method, i.e., via the estimated growth rates. The two-step method is often preferred due to its simplicity. The current research demonstrates that the two-step method is, however, only valid if the correct data transformation is applied and a strict experimental protocol is followed for all experiments. Based on a simulation study and a mathematical derivation, it was demonstrated that the logarithm of the growth rate should be used as a variance stabilizing transformation. Moreover, the one-step method leads to a more accurate estimation of the model parameters and a better approximation of the confidence intervals on the estimated parameters. Therefore, the one-step method is preferred and the two-step method should be avoided. Copyright © 2017. Published by Elsevier Ltd.
The Application of Artificial Neural Networks to Ore Reserve Estimation at Choghart Iron Ore Deposit
Directory of Open Access Journals (Sweden)
Seyyed Ali Nezamolhosseini
2017-01-01
Full Text Available Geo-statistical methods for reserve estimation are difficult to use when stationary conditions are not satisfied. Artificial Neural Networks (ANNs provide an alternative to geo-statistical techniques while considerably reducing the processing time required for development and application. In this paper the ANNs was applied to the Choghart iron ore deposit in Yazd province of Iran. Initially, an optimum Multi Layer Perceptron (MLP was constructed to estimate the Fe grade within orebody using the whole ore data of the deposit. Sensitivity analysis was applied for a number of hidden layers and neurons, different types of activation functions and learning rules. Optimal architectures for iron grade estimation were 3-20-10-1. In order to improve the network performance, the deposit was divided into four homogenous zones. Subsequently, all sensitivity analyses were carried out on each zone. Finally, a different optimum network was trained and Fe was estimated separately for each zone. Comparison of correlation coefficient (R and least mean squared error (MSE showed that the ANNs performed on four homogenous zones were far better than the nets applied to the overall ore body. Therefore, these optimized neural networks were used to estimate the distribution of iron grades and the iron resource in Choghart deposit. As a result of applying ANNs, the tonnage of ore for Choghart deposit is approximately estimated at 135.8 million tones with average grade of Fe at 56.14 percent. Results of reserve estimation using ANNs showed a good agreement with the geo-statistical methods applied to this ore body in another work.
Sustainable economic growth and exhaustible resources: A model and estimation for the US
Directory of Open Access Journals (Sweden)
Almuth Scholl
2002-01-01
Full Text Available This paper studies current models on sustainable economic growth with resource constraints and explores to what extent resource constraints can be overcome by substitution and technological change. We also study the problem of intergenerational equity and the different criteria that have been suggested in the literature. The central part of this paper is the presentation of stylized facts on exhaustible resources and an estimation of a basic model with resource constraints for US time series data. The estimated years left until depletion and the empirical trends of the ratios of capital stock and consumption to resources seem to indicate that there might be a threat to sustainable growth in the future. In our estimation, we obtain parameter values, which help to interpret the extent to which growth with exhaustible resources is sustainable.
The impact of oil price on additions to US proven reserves
International Nuclear Information System (INIS)
Farzin, Y.H.
2001-01-01
Departing from Hotelling's assumption of fixed and known reserves, this paper develops an economic model of additions to proven reserves that explicitly incorporates the effects of expected resource price, cumulative reserves development, and technological progress on reserve additions. The model treats additions to proven oil reserves as output of a production process in which drilling wells is a primary input to transform some of oil-in-place into the economic category of proven reserves. Application of the model to US data for the 1950-1995 period provides strong statistical support for the existence of all the three salient effects. We obtain an estimate of the price elasticity of reserve additions (absent from previous studies) which, although statistically highly significant, is rather small. Using this price elasticity estimate, it is shown that if in the face of steady economic growth, and hence, oil consumption, US oil import dependence is to be kept from rising in the future, ceteris paribus, a steady oil price increase in the range of 1.5-4.5% a year is essential
Estimating Quartz Reserves Using Compositional Kriging
Directory of Open Access Journals (Sweden)
J. Taboada
2013-01-01
Full Text Available The aim of this study was to determine spatial distribution and volume of four commercial quartz grades, namely, silicon metal, ferrosilicon, aggregate, and kaolin (depending on content in impurities in a quartz seam. The chemical and mineralogical composition of the reserves in the seam were determined from samples collected from outcrops, blasting operations, and exploratory drilling, and compositional kriging was used to calculate the volume and distribution of the reserves. A more accurate knowledge of the deposit ensures better mine planning, leading to higher profitability and an improved relationship with the environment.
Comparative study of the geostatistical ore reserve estimation method over the conventional methods
International Nuclear Information System (INIS)
Kim, Y.C.; Knudsen, H.P.
1975-01-01
Part I contains a comprehensive treatment of the comparative study of the geostatistical ore reserve estimation method over the conventional methods. The conventional methods chosen for comparison were: (a) the polygon method, (b) the inverse of the distance squared method, and (c) a method similar to (b) but allowing different weights in different directions. Briefly, the overall result from this comparative study is in favor of the use of geostatistics in most cases because the method has lived up to its theoretical claims. A good exposition on the theory of geostatistics, the adopted study procedures, conclusions and recommended future research are given in Part I. Part II of this report contains the results of the second and the third study objectives, which are to assess the potential benefits that can be derived by the introduction of the geostatistical method to the current state-of-the-art in uranium reserve estimation method and to be instrumental in generating the acceptance of the new method by practitioners through illustrative examples, assuming its superiority and practicality. These are given in the form of illustrative examples on the use of geostatistics and the accompanying computer program user's guide
Estimates of genetic parameters and genetic gains for growth traits ...
African Journals Online (AJOL)
Estimates of genetic parameters and genetic gains for growth traits of two Eucalyptus ... In South Africa, Eucalyptus urophylla is an important species due to its ... as hybrid parents to cross with E. grandis was 59.8% over the population mean.
NDE errors and their propagation in sizing and growth estimates
International Nuclear Information System (INIS)
Horn, D.; Obrutsky, L.; Lakhan, R.
2009-01-01
The accuracy attributed to eddy current flaw sizing determines the amount of conservativism required in setting tube-plugging limits. Several sources of error contribute to the uncertainty of the measurements, and the way in which these errors propagate and interact affects the overall accuracy of the flaw size and flaw growth estimates. An example of this calculation is the determination of an upper limit on flaw growth over one operating period, based on the difference between two measurements. Signal-to-signal comparison involves a variety of human, instrumental, and environmental error sources; of these, some propagate additively and some multiplicatively. In a difference calculation, specific errors in the first measurement may be correlated with the corresponding errors in the second; others may be independent. Each of the error sources needs to be identified and quantified individually, as does its distribution in the field data. A mathematical framework for the propagation of the errors can then be used to assess the sensitivity of the overall uncertainty to each individual error component. This paper quantifies error sources affecting eddy current sizing estimates and presents analytical expressions developed for their effect on depth estimates. A simple case study is used to model the analysis process. For each error source, the distribution of the field data was assessed and propagated through the analytical expressions. While the sizing error obtained was consistent with earlier estimates and with deviations from ultrasonic depth measurements, the error on growth was calculated as significantly smaller than that obtained assuming uncorrelated errors. An interesting result of the sensitivity analysis in the present case study is the quantification of the error reduction available from post-measurement compensation of magnetite effects. With the absolute and difference error equations, variance-covariance matrices, and partial derivatives developed in
International Nuclear Information System (INIS)
Wu Jingqin.
1989-01-01
Yang Chizhong filtering and inferential measurement method is a new method used for variable statistics of ore deposits. In order to apply this theory to estimate the uranium ore reserves under the circumstances of regular or irregular prospecting grids, small ore bodies, less sampling points, and complex occurrence, the author has used this method to estimate the ore reserves in five ore bodies of two deposits and achieved satisfactory results. It is demonstrated that compared with the traditional block measurement method, this method is simple and clear in formula, convenient in application, rapid in calculation, accurate in results, less expensive, and high economic benefits. The procedure and experience in the application of this method and the preliminary evaluation of its results are mainly described
Directory of Open Access Journals (Sweden)
Eleanor S Devenish Nelson
Full Text Available BACKGROUND: Demographic models are widely used in conservation and management, and their parameterisation often relies on data collected for other purposes. When underlying data lack clear indications of associated uncertainty, modellers often fail to account for that uncertainty in model outputs, such as estimates of population growth. METHODOLOGY/PRINCIPAL FINDINGS: We applied a likelihood approach to infer uncertainty retrospectively from point estimates of vital rates. Combining this with resampling techniques and projection modelling, we show that confidence intervals for population growth estimates are easy to derive. We used similar techniques to examine the effects of sample size on uncertainty. Our approach is illustrated using data on the red fox, Vulpes vulpes, a predator of ecological and cultural importance, and the most widespread extant terrestrial mammal. We show that uncertainty surrounding estimated population growth rates can be high, even for relatively well-studied populations. Halving that uncertainty typically requires a quadrupling of sampling effort. CONCLUSIONS/SIGNIFICANCE: Our results compel caution when comparing demographic trends between populations without accounting for uncertainty. Our methods will be widely applicable to demographic studies of many species.
Energy Technology Data Exchange (ETDEWEB)
Lepez, V
2002-12-01
The aim of this thesis is to build a statistical model of oil and gas fields' sizes distribution in a given sedimentary basin, for both the fields that exist in:the subsoil and those which have already been discovered. The estimation of all the parameters of the model via estimation of the density of the observations by model selection of piecewise polynomials by penalized maximum likelihood techniques enables to provide estimates of the total number of fields which are yet to be discovered, by class of size. We assume that the set of underground fields' sizes is an i.i.d. sample of unknown population with Levy-Pareto law with unknown parameter. The set of already discovered fields is a sub-sample without replacement from the previous which is 'size-biased'. The associated inclusion probabilities are to be estimated. We prove that the probability density of the observations is the product of the underlying density and of an unknown weighting function representing the sampling bias. An arbitrary partition of the sizes' interval being set (called a model), the analytical solutions of likelihood maximization enables to estimate both the parameter of the underlying Levy-Pareto law and the weighting function, which is assumed to be piecewise constant and based upon the partition. We shall add a monotonousness constraint over the latter, taking into account the fact that the bigger a field, the higher its probability of being discovered. Horvitz-Thompson-like estimators finally give the conclusion. We then allow our partitions to vary inside several classes of models and prove a model selection theorem which aims at selecting the best partition within a class, in terms of both Kuilback and Hellinger risk of the associated estimator. We conclude by simulations and various applications to real data from sedimentary basins of four continents, in order to illustrate theoretical as well as practical aspects of our model. (author)
Estimates of Uncertainty around the RBA's Forecasts
Peter Tulip; Stephanie Wallace
2012-01-01
We use past forecast errors to construct confidence intervals and other estimates of uncertainty around the Reserve Bank of Australia's forecasts of key macroeconomic variables. Our estimates suggest that uncertainty about forecasts is high. We find that the RBA's forecasts have substantial explanatory power for the inflation rate but not for GDP growth.
Bayesian methods to estimate urban growth potential
Smith, Jordan W.; Smart, Lindsey S.; Dorning, Monica; Dupéy, Lauren Nicole; Méley, Andréanne; Meentemeyer, Ross K.
2017-01-01
Urban growth often influences the production of ecosystem services. The impacts of urbanization on landscapes can subsequently affect landowners’ perceptions, values and decisions regarding their land. Within land-use and land-change research, very few models of dynamic landscape-scale processes like urbanization incorporate empirically-grounded landowner decision-making processes. Very little attention has focused on the heterogeneous decision-making processes that aggregate to influence broader-scale patterns of urbanization. We examine the land-use tradeoffs faced by individual landowners in one of the United States’ most rapidly urbanizing regions − the urban area surrounding Charlotte, North Carolina. We focus on the land-use decisions of non-industrial private forest owners located across the region’s development gradient. A discrete choice experiment is used to determine the critical factors influencing individual forest owners’ intent to sell their undeveloped properties across a series of experimentally varied scenarios of urban growth. Data are analyzed using a hierarchical Bayesian approach. The estimates derived from the survey data are used to modify a spatially-explicit trend-based urban development potential model, derived from remotely-sensed imagery and observed changes in the region’s socioeconomic and infrastructural characteristics between 2000 and 2011. This modeling approach combines the theoretical underpinnings of behavioral economics with spatiotemporal data describing a region’s historical development patterns. By integrating empirical social preference data into spatially-explicit urban growth models, we begin to more realistically capture processes as well as patterns that drive the location, magnitude and rates of urban growth.
International Nuclear Information System (INIS)
Stenmark, Matthew H.; Cao, Yue; Wang, Hesheng; Jackson, Andrew; Ben-Josef, Edgar; Ten Haken, Randall K.; Lawrence, Theodore S.; Feng, Mary
2014-01-01
Purpose: To estimate the limit of functional liver reserve for safe application of hepatic irradiation using changes in indocyanine green, an established assay of liver function. Materials and methods: From 2005 to 2011, 60 patients undergoing hepatic irradiation were enrolled in a prospective study assessing the plasma retention fraction of indocyanine green at 15-min (ICG-R15) prior to, during (at 60% of planned dose), and after radiotherapy (RT). The limit of functional liver reserve was estimated from the damage fraction of functional liver (DFL) post-RT [1 − (ICG-R15 pre-RT /ICG-R15 post-RT )] where no toxicity was observed using a beta distribution function. Results: Of 48 evaluable patients, 3 (6%) developed RILD, all within 2.5 months of completing RT. The mean ICG-R15 for non-RILD patients pre-RT, during-RT and 1-month post-RT was 20.3%(SE 2.6), 22.0%(3.0), and 27.5%(2.8), and for RILD patients was 6.3%(4.3), 10.8%(2.7), and 47.6%(8.8). RILD was observed at post-RT damage fractions of ⩾78%. Both DFL assessed by during-RT ICG and MLD predicted for DFL post-RT (p < 0.0001). Limiting the post-RT DFL to 50%, predicted a 99% probability of a true complication rate <15%. Conclusion: The DFL as assessed by changes in ICG during treatment serves as an early indicator of a patient’s tolerance to hepatic irradiation
Energy Technology Data Exchange (ETDEWEB)
Sakai, Haruna; Yoshioka, Katsunobu; Yamagami, Keiko [Osaka City General Hospital (Japan)] (and others)
2002-06-01
A 34-year-old man with neurofibromatosis type 1, who had received radiation therapy after the excision of a brain tumor 5 years earlier, was admitted to our hospital with vomiting and weight loss. Cortisol and adrenocorticotropin (ACTH) were undetectable before and after administration of 100 {mu}g corticotropin releasing hormone. The level of growth hormone without stimulation was 24.7 ng/ml. We diagnosed him to have complete ACTH deficiency attributable to radiation therapy. This is the first known case of a patient with complete ACTH deficiency after radiation therapy and a growth hormone reserve that remained normal. (author)
International Nuclear Information System (INIS)
Sakai, Haruna; Yoshioka, Katsunobu; Yamagami, Keiko
2002-01-01
A 34-year-old man with neurofibromatosis type 1, who had received radiation therapy after the excision of a brain tumor 5 years earlier, was admitted to our hospital with vomiting and weight loss. Cortisol and adrenocorticotropin (ACTH) were undetectable before and after administration of 100 μg corticotropin releasing hormone. The level of growth hormone without stimulation was 24.7 ng/ml. We diagnosed him to have complete ACTH deficiency attributable to radiation therapy. This is the first known case of a patient with complete ACTH deficiency after radiation therapy and a growth hormone reserve that remained normal. (author)
Leung, Michael; Bassani, Diego G; Racine-Poon, Amy; Goldenberg, Anna; Ali, Syed Asad; Kang, Gagandeep; Premkumar, Prasanna S; Roth, Daniel E
2017-09-10
Conditioning child growth measures on baseline accounts for regression to the mean (RTM). Here, we present the "conditional random slope" (CRS) model, based on a linear-mixed effects model that incorporates a baseline-time interaction term that can accommodate multiple data points for a child while also directly accounting for RTM. In two birth cohorts, we applied five approaches to estimate child growth velocities from 0 to 12 months to assess the effect of increasing data density (number of measures per child) on the magnitude of RTM of unconditional estimates, and the correlation and concordance between the CRS and four alternative metrics. Further, we demonstrated the differential effect of the choice of velocity metric on the magnitude of the association between infant growth and stunting at 2 years. RTM was minimally attenuated by increasing data density for unconditional growth modeling approaches. CRS and classical conditional models gave nearly identical estimates with two measures per child. Compared to the CRS estimates, unconditional metrics had moderate correlation (r = 0.65-0.91), but poor agreement in the classification of infants with relatively slow growth (kappa = 0.38-0.78). Estimates of the velocity-stunting association were the same for CRS and classical conditional models but differed substantially between conditional versus unconditional metrics. The CRS can leverage the flexibility of linear mixed models while addressing RTM in longitudinal analyses. © 2017 The Authors American Journal of Human Biology Published by Wiley Periodicals, Inc.
Directory of Open Access Journals (Sweden)
Ma. Josefa Pante
2007-06-01
Full Text Available Genetic improvement of performance traits of maricultured species is becoming an important concern. Improvement of performance traits is important for two reasons: it enhances the growth and survival of the animals and it translates to economic gains to the fish farmer. In the sea urchin, Tripneustes gratilla, growth performance of the different families and heritabilities for wet weight, test diameter and test height were estimated from 1,020 offspring from a mating of each of the 15 males with 1 or 2 females. Measurements were done monthly starting at the grow-out stage or four months after hatching. There were significant family differences for the performance traits in sea urchin reared in tanks at the BML hatchery as revealed by ANOVA. Estimates of heritabilities based on the sire component of variance were low for wet weight (0.027, test diameter (0.033 and zero for test height. Heritabilities estimated from the dam component of variance were low for wet weight (0.063, moderate for test diameter (0.286 and test height (0.227. The results indicate that test diameter and wet weight have lowly heritable traits, which means that mass or individual selection may not be the best method for improving the traits for sea urchin populations in Bolinao. Other methods such as family and combined family selection should be explored.
Lindqvist, R
2006-07-01
Turbidity methods offer possibilities for generating data required for addressing microorganism variability in risk modeling given that the results of these methods correspond to those of viable count methods. The objectives of this study were to identify the best approach for determining growth parameters based on turbidity data and use of a Bioscreen instrument and to characterize variability in growth parameters of 34 Staphylococcus aureus strains of different biotypes isolated from broiler carcasses. Growth parameters were estimated by fitting primary growth models to turbidity growth curves or to detection times of serially diluted cultures either directly or by using an analysis of variance (ANOVA) approach. The maximum specific growth rates in chicken broth at 17 degrees C estimated by time to detection methods were in good agreement with viable count estimates, whereas growth models (exponential and Richards) underestimated growth rates. Time to detection methods were selected for strain characterization. The variation of growth parameters among strains was best described by either the logistic or lognormal distribution, but definitive conclusions require a larger data set. The distribution of the physiological state parameter ranged from 0.01 to 0.92 and was not significantly different from a normal distribution. Strain variability was important, and the coefficient of variation of growth parameters was up to six times larger among strains than within strains. It is suggested to apply a time to detection (ANOVA) approach using turbidity measurements for convenient and accurate estimation of growth parameters. The results emphasize the need to consider implications of strain variability for predictive modeling and risk assessment.
Directory of Open Access Journals (Sweden)
David Shilane
2013-01-01
Full Text Available The negative binomial distribution becomes highly skewed under extreme dispersion. Even at moderately large sample sizes, the sample mean exhibits a heavy right tail. The standard normal approximation often does not provide adequate inferences about the data's expected value in this setting. In previous work, we have examined alternative methods of generating confidence intervals for the expected value. These methods were based upon Gamma and Chi Square approximations or tail probability bounds such as Bernstein's inequality. We now propose growth estimators of the negative binomial mean. Under high dispersion, zero values are likely to be overrepresented in the data. A growth estimator constructs a normal-style confidence interval by effectively removing a small, predetermined number of zeros from the data. We propose growth estimators based upon multiplicative adjustments of the sample mean and direct removal of zeros from the sample. These methods do not require estimating the nuisance dispersion parameter. We will demonstrate that the growth estimators' confidence intervals provide improved coverage over a wide range of parameter values and asymptotically converge to the sample mean. Interestingly, the proposed methods succeed despite adding both bias and variance to the normal approximation.
Can we estimate bacterial growth rates from ribosomal RNA content?
Energy Technology Data Exchange (ETDEWEB)
Kemp, P.F.
1995-12-31
Several studies have demonstrated a strong relationship between the quantity of RNA in bacterial cells and their growth rate under laboratory conditions. It may be possible to use this relationship to provide information on the activity of natural bacterial communities, and in particular on growth rate. However, if this approach is to provide reliably interpretable information, the relationship between RNA content and growth rate must be well-understood. In particular, a requisite of such applications is that the relationship must be universal among bacteria, or alternately that the relationship can be determined and measured for specific bacterial taxa. The RNA-growth rate relationship has not been used to evaluate bacterial growth in field studies, although RNA content has been measured in single cells and in bulk extracts of field samples taken from coastal environments. These measurements have been treated as probable indicators of bacterial activity, but have not yet been interpreted as estimators of growth rate. The primary obstacle to such interpretations is a lack of information on biological and environmental factors that affect the RNA-growth rate relationship. In this paper, the available data on the RNA-growth rate relationship in bacteria will be reviewed, including hypotheses regarding the regulation of RNA synthesis and degradation as a function of growth rate and environmental factors; i.e. the basic mechanisms for maintaining RNA content in proportion to growth rate. An assessment of the published laboratory and field data, the current status of this research area, and some of the remaining questions will be presented.
The Biasing Effects of Unmodeled ARMA Time Series Processes on Latent Growth Curve Model Estimates
Sivo, Stephen; Fan, Xitao; Witta, Lea
2005-01-01
The purpose of this study was to evaluate the robustness of estimated growth curve models when there is stationary autocorrelation among manifest variable errors. The results suggest that when, in practice, growth curve models are fitted to longitudinal data, alternative rival hypotheses to consider would include growth models that also specify…
Tropical dendrochemistry: A novel approach to estimate age and growth from ringless trees
International Nuclear Information System (INIS)
Poussart, P.; Myneni, S.; Lanzirotti, A.
2006-01-01
Although tropical forests play an active role in the global carbon cycle and climate, their growth history remains poorly characterized compared to other ecosystems on the planet. Trees are prime candidates for the extraction of paleoclimate archives as they can be probed sub-annually, are widely distributed and can live for over 1400 years. However, dendrochronological techniques have found limited applications in the tropics because trees often lack visible growth rings. Alternative methods exist (dendrometry, radio- and stable isotopes), but the derived records are either of short-duration, lack seasonal resolution or are prohibitively labor intensive to produce. Here, we show the first X-ray microprobe synchrotron record of calcium (Ca) from a ringless Miliusa velutina tree from Thailand and use it to estimate the tree's age and growth history. The Ca age model agrees within (le)2 years of bomb-radiocarbon age estimates and confirms that the cycles are seasonal. The amplitude of the Ca annual cycle is correlated significantly with growth and annual Ca maxima correlate with the amount of dry season rainfall. Synchrotron measurements are fast and producing sufficient numbers of replicated multi-century tropical dendrochemical climate records now seems analytically feasible
Sturm, J.-E.; de Haan, J.
2005-01-01
Two important problems exist in cross-country growth studies: outliers and model uncertainty. Employing Sala-i-Martin's (1997a,b) data set, we first use robust estimation and analyze to what extent outliers influence OLS regressions. We then use both OLS and robust estimation techniques in applying
Energy Technology Data Exchange (ETDEWEB)
Lepez, V.
2002-12-01
The aim of this thesis is to build a statistical model of oil and gas fields' sizes distribution in a given sedimentary basin, for both the fields that exist in:the subsoil and those which have already been discovered. The estimation of all the parameters of the model via estimation of the density of the observations by model selection of piecewise polynomials by penalized maximum likelihood techniques enables to provide estimates of the total number of fields which are yet to be discovered, by class of size. We assume that the set of underground fields' sizes is an i.i.d. sample of unknown population with Levy-Pareto law with unknown parameter. The set of already discovered fields is a sub-sample without replacement from the previous which is 'size-biased'. The associated inclusion probabilities are to be estimated. We prove that the probability density of the observations is the product of the underlying density and of an unknown weighting function representing the sampling bias. An arbitrary partition of the sizes' interval being set (called a model), the analytical solutions of likelihood maximization enables to estimate both the parameter of the underlying Levy-Pareto law and the weighting function, which is assumed to be piecewise constant and based upon the partition. We shall add a monotonousness constraint over the latter, taking into account the fact that the bigger a field, the higher its probability of being discovered. Horvitz-Thompson-like estimators finally give the conclusion. We then allow our partitions to vary inside several classes of models and prove a model selection theorem which aims at selecting the best partition within a class, in terms of both Kuilback and Hellinger risk of the associated estimator. We conclude by simulations and various applications to real data from sedimentary basins of four continents, in order to illustrate theoretical as well as practical aspects of our model. (author)
Revisiting the constant growth angle: Estimation and verification via rigorous thermal modeling
Virozub, Alexander; Rasin, Igal G.; Brandon, Simon
2008-12-01
Methods for estimating growth angle ( θgr) values, based on the a posteriori analysis of directionally solidified material (e.g. drops) often involve assumptions of negligible gravitational effects as well as a planar solid/liquid interface during solidification. We relax both of these assumptions when using experimental drop shapes from the literature to estimate the relevant growth angles at the initial stages of solidification. Assumed to be constant, we use these values as input into a rigorous heat transfer and solidification model of the growth process. This model, which is shown to reproduce the experimental shape of a solidified sessile water drop using the literature value of θgr=0∘, yields excellent agreement with experimental profiles using our estimated values for silicon ( θgr=10∘) and germanium ( θgr=14.3∘) solidifying on an isotropic crystalline surface. The effect of gravity on the solidified drop shape is found to be significant in the case of germanium, suggesting that gravity should either be included in the analysis or that care should be taken that the relevant Bond number is truly small enough in each measurement. The planar solidification interface assumption is found to be unjustified. Although this issue is important when simulating the inflection point in the profile of the solidified water drop, there are indications that solidified drop shapes (at least in the case of silicon) may be fairly insensitive to the shape of this interface.
International Nuclear Information System (INIS)
Brookins, D.G.
1981-12-01
In this module geological and geochemical data pertinent to locating, mining, and milling of uranium are examined. Chapters are devoted to: uranium source characteristics; uranium ore exploration methods; uranium reserve estimation for sandstone deposits; mining; milling; conversion processes for uranium; and properties of uranium, thorium, plutonium and their oxides and carbides
Lithium reserves and resources
International Nuclear Information System (INIS)
Evans, R.K.
1978-01-01
As a result of accelerating research efforts in the fields of secondary batteries and thermonuclear power generation, concern has been expressed in certain quarters regarding the availability, in sufficient quantities, of lithium. As part of a recent study by the National Research Council on behalf of the Energy Research and Development Administration, a subpanel was formed to consider the outlook for lithium. Principal areas of concern were reserves, resources and the 'surplus' available for energy applications after allowing for the growth in current lithium applications. Reserves and resources were categorized into four classes ranging from fully proved reserves to resources which are probably dependent upon the marketing of co-products to become economically attractive. Because of the proprietary nature of data on beneficiation and processing recoveries, the tonnages of available lithium are expressed in terms of plant feed. However, highly conservative assumptions have been made concerning mining recoveries and these go a considerable way to accounting for total losses. Western World reserves and resources of all classes are estimated at 10.6 million tonnes Li of which 3.5 million tonnes Li are located in the United States. Current United States capacity, virtually equivalent to Western World capacity, is 4700 tonnes Li and production in 1976 approximated to 3500 tonnes Li. Production for current applications is expected to grow to approx. 10,000 tonnes in year 2000 and 13,000 tonnes a decade later. The massive excess of reserves and resources over that necessary to support conventional requirements has limited the amount of justifiable exploration expenditures; on the last occasion, there was a a major increase in demand (by the USAEA) reserves and capacity were increased rapidly. There are no foreseeable reasons why this shouldn't happen again when the need is clear. (author)
Directory of Open Access Journals (Sweden)
Dong Sun Lee
2014-01-01
Full Text Available Two mechanistic microbial growth models (Huang’s model and model of Baranyi and Roberts given in differential and integrated equation forms were compared in predicting the microbial growth and shelf life under dynamic temperature storage and distribution conditions. Literatures consistently reporting the microbial growth data under constant and changing temperature conditions were selected to obtain the primary model parameters, set up the secondary models, and apply them to predict the microbial growth and shelf life under fluctuating temperatures. When evaluated by general estimation behavior, bias factor, accuracy factor, and root-mean-square error, Huang’s model was comparable to Baranyi and Roberts’ model in the capability to estimate microbial growth under dynamic temperature conditions. Its simple form of single differential equation incorporating directly the growth rate and lag time may work as an advantage to be used in online shelf life estimation by using the electronic device.
Chicle harvesting and extractive reserves in the Maya Biosphere b: Reserve
Energy Technology Data Exchange (ETDEWEB)
Dugelby, B.L.
1995-12-31
Chicle latex has been extracted from the forests of northern Guatemala for over 100 years and is a key element in the extractive reserve component of the Maya Biosphere Reserve. The carrying capacity of the reserve for chicle extraction can be estimated from a model incorporating ecological data (such as latex yields per tree and population structure of chicle trees, Manilkara zapota, Sapot.) with socio-ecological and political information concerning camp and chicle resource availability, harvester tapping behavior, and historical and present-day institutional organization. I estimate that chicle harvestors currently utilize and area larger than the multiple use zone of the reserve in a unsustainable manner. Simple reduction of harvestors numbers will not ensure sustainability; institutional reforms are also in order. Extractive reserves can play an important role in preserving tropical forests. However, their effectiveness is highly dependent on prevailing ecological, socio-economic, and political conditions. Wise planning and management of extractive reserves demands an understanding of the system`s carrying capacity. In addition, a strong institutional foundation is necessary to assure effective monitoring and enforcement of harvesting regulations.
Li, Zhenhai; Li, Na; Li, Zhenhong; Wang, Jianwen; Liu, Chang
2017-10-01
Rapid real-time monitoring of wheat nitrogen (N) status is crucial for precision N management during wheat growth. In this study, Multi Lookup Table (Multi-LUT) approach based on the N-PROSAIL model parameters setting at different growth stages was constructed to estimating canopy N density (CND) in winter wheat. The results showed that the estimated CND was in line with with measured CND, with the determination coefficient (R2) and the corresponding root mean square error (RMSE) values of 0.80 and 1.16 g m-2, respectively. Time-consuming of one sample estimation was only 6 ms under the test machine with CPU configuration of Intel(R) Core(TM) i5-2430 @2.40GHz quad-core. These results confirmed the potential of using Multi-LUT approach for CND retrieval in winter wheat at different growth stages and under variables climatic conditions.
An Evaluation of Growth Models as Predictive Tools for Estimates at Completion (EAC)
National Research Council Canada - National Science Library
Trahan, Elizabeth N
2009-01-01
...) as the Estimates at Completion (EAC). Our research evaluates the prospect of nonlinear growth modeling as an alternative to the current predictive tools used for calculating EAC, such as the Cost Performance Index (CPI...
International Nuclear Information System (INIS)
Hwang, Eui-Hyo
1999-01-01
The aim of this study is the assessment of the physiological implication of estimated parameters and the clinical value of this analyzing method for hepatic functional reserve estimation. After venous injection of 185 MBq of GSA, fifteen sequential sets of SPECT data were acquired for 15 minutes. First 5 sets SPECT images were analyzed by Patlak plot and hepatic GSA clearance was obtained in each matrix. The sum of hepatic GSA clearance in each matrix (total hepatic GSA clearance) was calculated as an index of whole liver functional reserve. Total hepatic GSA clearance was compared with receptor index or effective blood flow (EHBF) of whole liver which were analyzed by Direct Integral Linear Least Square Regression (DILS) method for the assessment of the physiological implications of hepatic GSA clearance. The clinical value of total hepatic GSA clearance was assessed in comparisons with the conventional hepatic function test. A very good correlations were observed between total hepatic GSA clearance and receptor index, whereas the correlations between total hepatic GSA clearance and EHBF were not significant. Significant correlations were also observed between total hepatic GSA clearance and the conventional hepatic function tests, such as choline esterase, albumin, hepaplastin test, ICG R15. (K.H.)
Hu, G; Gu, W; Bai, Q L; Wang, B Q
2013-04-26
Genetic parameters and breeding values for growth traits were estimated in the first and, currently, the only family selective breeding program for rainbow trout (Oncorhynchus mykiss) in China. Genetic and phenotypic data were collected for growth traits from 75 full-sibling families with a 2-generation pedigree. Genetic parameters and breeding values for growth traits of rainbow trout were estimated using the derivative-free restricted maximum likelihood method. The goodness-of-fit of the models was tested using Akaike and Bayesian information criteria. Genetic parameters and breeding values were estimated using the best-fit model for each trait. The values for heritability estimating body weight and length ranged from 0.20 to 0.45 and from 0.27 to 0.60, respectively, and the heritability of condition factor was 0.34. Our results showed a moderate degree of heritability for growth traits in this breeding program and suggested that the genetic and phenotypic tendency of body length, body weight, and condition factor were similar. Therefore, the selection of phenotypic values based on pedigree information was also suitable in this research population.
International strategies for growth : monetizing gas reserves to add value to the bottom line
International Nuclear Information System (INIS)
Mihaichuk, G.
1998-01-01
The direction taken by oil and gas companies, including TransCanada International, in their strategy for growth in global energy markets was discussed. The role that gas plays in meeting the objectives was examined and the different ways in which gas reserves and investments in the gas sector are being turned into high-performing vehicles for adding value to the bottom line were described. Deregulation of, and competition within, the gas and electric power industries are the driving factors for changes within the energy industries. Natural gas will be a winner because it is the first choice for new power generation. Many companies have entered the international playing field to take advantage of the opportunities in international markets. The problems and solutions to monetizing natural gas reserves, some of the international political issues such as regulatory uncertainty, cross-border disputes, lack of regional integration, and sanctions, and how these adverse effects may be mitigated through mergers, acquisitions, or joint ventures, are explored. 14 figs
Genetic and phenotypic parameter estimates for growth traits of Hainan Black goat in southern China
Zhou, Han Lin; Gu, Li Hong; Sun, Yanyan; Xu, Tie Shan; Rong, Guang
2015-01-01
Genetic improvement of the growth of Hainan Black goats is a major concern as the breed is an important meat-type goat raised in southern China. To estimate genetic and phenotypic parameters for growth traits for this breed, a population of 1354 Hainan Black goats born and maintained at the
Directory of Open Access Journals (Sweden)
Prabuddha Manjula
2018-01-01
Full Text Available Objective This study estimated the genetic parameters for body weight gain and growth curve parameter traits in Korean native chicken (KNC. Methods A total of 585 F1 chickens were used along with 88 of their F0 birds. Body weights were measured every 2 weeks from hatching to 20 weeks of age to measure weight gain at 2-week intervals. For each individual, a logistic growth curve model was fitted to the longitudinal growth dataset to obtain three growth curve parameters (α, asymptotic final body weight; β, inflection point; and γ, constant scale that was proportional to the overall growth rate. Genetic parameters were estimated based on the linear-mixed model using a restricted maximum likelihood method. Results Heritability estimates of body weight gain traits were low to high (0.057 to 0.458. Heritability estimates for α, β, and γ were 0.211±0.08, 0.249±0.09, and 0.095±0.06, respectively. Both genetic and phenotypic correlations between weight gain traits ranged from −0.527 to 0.993. Genetic and phenotypic correlation between the growth curve parameters and weight gain traits ranged from −0.968 to 0.987. Conclusion Based on the results of this study population, we suggest that the KNC could be used for selective breeding between 6 and 8 weeks of age to enhance the overall genetic improvement of growth traits. After validation of these results in independent studies, these findings will be useful for further optimization of breeding programs for KNC.
Risk spreading, connectivity, and optimal reserve spacing.
Blowes, Shane A; Connolly, Sean R
2012-01-01
Two important processes determining the dynamics of spatially structured populations are dispersal and the spatial covariance of demographic fluctuations. Spatially explicit approaches to conservation, such as reserve networks, must consider the tension between these two processes and reach a balance between distances near enough to maintain connectivity, but far enough to benefit from risk spreading. Here, we model this trade-off. We show how two measures of metapopulation persistence depend on the shape of the dispersal kernel and the shape of the distance decay in demographic covariance, and we consider the implications of this trade-off for reserve spacing. The relative rates of distance decay in dispersal and demographic covariance determine whether the long-run metapopulation growth rate, and quasi-extinction risk, peak for adjacent patches or intermediately spaced patches; two local maxima in metapopulation persistence are also possible. When dispersal itself fluctuates over time, the trade-off changes. Temporal variation in mean distance that propagules are dispersed (i.e., propagule advection) decreases metapopulation persistence and decreases the likelihood that persistence will peak for adjacent patches. Conversely, variation in diffusion (the extent of random spread around mean dispersal) increases metapopulation persistence overall and causes it to peak at shorter inter-patch distances. Thus, failure to consider temporal variation in dispersal processes increases the risk that reserve spacings will fail to meet the objective of ensuring metapopulation persistence. This study identifies two phenomena that receive relatively little attention in empirical work on reserve spacing, but that can qualitatively change the effectiveness of reserve spacing strategies: (1) the functional form of the distance decay in covariance among patch-specific demographic rates and (2) temporal variation in the shape of the dispersal kernel. The sensitivity of metapopulation
Status of fossil fuel reserves; Etat des reserves des combustibles fossiles
Energy Technology Data Exchange (ETDEWEB)
Laherrere, J
2005-07-01
Reserves represent the sum of past and future productions up to the end of production. In most countries the reserve data of fields are confidential. Therefore, fossil fuel reserves are badly known because the published data are more political than technical and many countries make a confusion between resources and reserves. The cumulated production of fossil fuels represents only between a third and a fifth of the ultimate reserves. The production peak will take place between 2020 and 2050. In the ultimate reserves, which extrapolate the past, the fossil fuels represent three thirds of the overall energy. This document analyses the uncertainties linked with fossil fuel reserves: reliability of published data, modeling of future production, comparison with other energy sources, energy consumption forecasts, reserves/production ratio, exploitation of non-conventional hydrocarbons (tar sands, extra-heavy oils, bituminous shales, coal gas, gas shales, methane in overpressure aquifers, methane hydrates), technology impacts, prices impact, and reserves growth. (J.S.)
Directory of Open Access Journals (Sweden)
Mark W Schwartz
Full Text Available Montane forests of western China provide an opportunity to establish baseline studies for climate change. The region is being impacted by climate change, air pollution, and significant human impacts from tourism. We analyzed forest stand structure and climate-growth relationships from Jiuzhaigou National Nature Reserve in northwestern Sichuan province, along the eastern edge of the Tibetan plateau. We conducted a survey to characterize forest stand diversity and structure in plots occurring between 2050 and 3350 m in elevation. We also evaluated seedling and sapling recruitment and tree-ring data from four conifer species to assess: 1 whether the forest appears in transition toward increased hardwood composition; 2 if conifers appear stressed by recent climate change relative to hardwoods; and 3 how growth of four dominant species responds to recent climate. Our study is complicated by clear evidence of 20(th century timber extraction. Focusing on regions lacking evidence of logging, we found a diverse suite of conifers (Pinus, Abies, Juniperus, Picea, and Larix strongly dominate the forest overstory. We found population size structures for most conifer tree species to be consistent with self-replacement and not providing evidence of shifting composition toward hardwoods. Climate-growth analyses indicate increased growth with cool temperatures in summer and fall. Warmer temperatures during the growing season could negatively impact conifer growth, indicating possible seasonal climate water deficit as a constraint on growth. In contrast, however, we found little relationship to seasonal precipitation. Projected warming does not yet have a discernible signal on trends in tree growth rates, but slower growth with warmer growing season climates suggests reduced potential future forest growth.
Baker, Robert L; Leong, Wen Fung; An, Nan; Brock, Marcus T; Rubin, Matthew J; Welch, Stephen; Weinig, Cynthia
2018-02-01
We develop Bayesian function-valued trait models that mathematically isolate genetic mechanisms underlying leaf growth trajectories by factoring out genotype-specific differences in photosynthesis. Remote sensing data can be used instead of leaf-level physiological measurements. Characterizing the genetic basis of traits that vary during ontogeny and affect plant performance is a major goal in evolutionary biology and agronomy. Describing genetic programs that specifically regulate morphological traits can be complicated by genotypic differences in physiological traits. We describe the growth trajectories of leaves using novel Bayesian function-valued trait (FVT) modeling approaches in Brassica rapa recombinant inbred lines raised in heterogeneous field settings. While frequentist approaches estimate parameter values by treating each experimental replicate discretely, Bayesian models can utilize information in the global dataset, potentially leading to more robust trait estimation. We illustrate this principle by estimating growth asymptotes in the face of missing data and comparing heritabilities of growth trajectory parameters estimated by Bayesian and frequentist approaches. Using pseudo-Bayes factors, we compare the performance of an initial Bayesian logistic growth model and a model that incorporates carbon assimilation (A max ) as a cofactor, thus statistically accounting for genotypic differences in carbon resources. We further evaluate two remotely sensed spectroradiometric indices, photochemical reflectance (pri2) and MERIS Terrestrial Chlorophyll Index (mtci) as covariates in lieu of A max , because these two indices were genetically correlated with A max across years and treatments yet allow much higher throughput compared to direct leaf-level gas-exchange measurements. For leaf lengths in uncrowded settings, including A max improves model fit over the initial model. The mtci and pri2 indices also outperform direct A max measurements. Of particular
Small-vessel Survey and Auction Sampling to Estimate Growth and Maturity of Eteline Snappers
National Oceanic and Atmospheric Administration, Department of Commerce — Small-vessel Survey and Auction Sampling to Estimate Growth and Maturity of Eteline Snappers and Improve Data-Limited Stock Assessments. This biosampling project...
International Nuclear Information System (INIS)
See, Kok Fong; Coelli, Tim
2013-01-01
This study examines the total factor productivity (TFP) growth of the Malaysian electricity generation industry over the 1998 to 2005 period. The stochastic frontier analysis (SFA) approach is used to measure TFP change and decompose TFP growth into efficiency change and technical progress. We find that it achieved average annual TFP growth of 2.34%, with technical change contributing the most to the TFP growth over the eight year period. We hence hypothesise that the new power plants with their newer capital-embodied technologies commencing during the sample period are likely to be the main reason for this strong technical change. In addition, it is also noted that this estimate for the Malaysian electricity generation industry is larger than the estimate obtained for the electricity sector as a whole, where we obtain 1.34% per year for a comparable period. -- Highlights: •This is the first empirical study that examines the TFP growth of the Malaysian electricity generation industry using the SFA method. •An average annual TFP change of the Malaysian electricity generation industry over eight years (1998-2005) has been achieved at 2.34% per year. •The technical progress contributing the most to the TFP growth and technical efficiency change and scale change making small contributions over the sample period
Nonparametric estimation of age-specific reference percentile curves with radial smoothing.
Wan, Xiaohai; Qu, Yongming; Huang, Yao; Zhang, Xiao; Song, Hanping; Jiang, Honghua
2012-01-01
Reference percentile curves represent the covariate-dependent distribution of a quantitative measurement and are often used to summarize and monitor dynamic processes such as human growth. We propose a new nonparametric method based on a radial smoothing (RS) technique to estimate age-specific reference percentile curves assuming the underlying distribution is relatively close to normal. We compared the RS method with both the LMS and the generalized additive models for location, scale and shape (GAMLSS) methods using simulated data and found that our method has smaller estimation error than the two existing methods. We also applied the new method to analyze height growth data from children being followed in a clinical observational study of growth hormone treatment, and compared the growth curves between those with growth disorders and the general population. Copyright © 2011 Elsevier Inc. All rights reserved.
Zahari, Zakirah Mohd; Zubaidah Adnan, Siti; Kanthasamy, Ramesh; Saleh, Suriyati; Samad, Noor Asma Fazli Abdul
2018-03-01
The specification of the crystal product is usually given in terms of crystal size distribution (CSD). To this end, optimal cooling strategy is necessary to achieve the CSD. The direct design control involving analytical CSD estimator is one of the approaches that can be used to generate the set-point. However, the effects of temperature on the crystal growth rate are neglected in the estimator. Thus, the temperature dependence on the crystal growth rate needs to be considered in order to provide an accurate set-point. The objective of this work is to extend the analytical CSD estimator where Arrhenius expression is employed to cover the effects of temperature on the growth rate. The application of this work is demonstrated through a potassium sulphate crystallisation process. Based on specified target CSD, the extended estimator is capable of generating the required set-point where a proposed controller successfully maintained the operation at the set-point to achieve the target CSD. Comparison with other cooling strategies shows a reduction up to 18.2% of the total number of undesirable crystals generated from secondary nucleation using linear cooling strategy is achieved.
Determination of oil and gas reserves. 2. ed.
International Nuclear Information System (INIS)
Aguilera, R.; MacKay, V.
2004-01-01
This book was prepared by more than 40 contributing authors with expertise in a wide range of topics related to oil and gas reserves. It represents a collaborative effort to find definitions and guidelines for the classification of reserves that is acceptable to the oil industry, evaluators, oil and gas companies, financial agencies, securities commissions and government departments. This second edition is an update of the original work that was published in 1994 which compares estimates of reserves and their classification. The new edition includes changes that have occurred in the past 10 years and expands on the processes that are used to estimate reserves. New techniques for assessing risk were also included. The book is divided into four parts entitled: (1) definitions and guidelines for estimating and classifying oil and gas resources and reserves, (2) determination of in-place resources, (3) estimation of recovery factors and forecasting of recoverable hydrocarbons, and (4) prices, economics and markets. The second edition includes new sections dealing with geostatistics, natural gas balance calculations, reserves estimates in naturally fractured reservoirs, and new developments in estimating recovery factors through enhanced recovery methods such as horizontal drilling. The objective was to develop a reference that is of great value to geologists, engineers and technical persons involved in estimating reserves. refs., tabs., figs
DEFF Research Database (Denmark)
Garde, Eva; Heide-Jørgensen, Mads Peter; Ditlevsen, Susanne
2012-01-01
Ages of marine mammals have traditionally been estimated by counting dentinal growth layers in teeth. However, this method is difficult to use on narwhals (Monodon monoceros) because of their special tooth structures. Alternative methods are therefore needed. The aspartic acid racemization (AAR......) technique has been used in age estimation studies of cetaceans, including narwhals. The purpose of this study was to estimate a species-specific racemization rate for narwhals by regressing aspartic acid D/L ratios in eye lens nuclei against growth layer groups in tusks (n=9). Two racemization rates were...
Schwarz, L.K.; Runge, M.C.
2009-01-01
Age estimation of individuals is often an integral part of species management research, and a number of ageestimation techniques are commonly employed. Often, the error in these techniques is not quantified or accounted for in other analyses, particularly in growth curve models used to describe physiological responses to environment and human impacts. Also, noninvasive, quick, and inexpensive methods to estimate age are needed. This research aims to provide two Bayesian methods to (i) incorporate age uncertainty into an age-length Schnute growth model and (ii) produce a method from the growth model to estimate age from length. The methods are then employed for Florida manatee (Trichechus manatus) carcasses. After quantifying the uncertainty in the aging technique (counts of ear bone growth layers), we fit age-length data to the Schnute growth model separately by sex and season. Independent prior information about population age structure and the results of the Schnute model are then combined to estimate age from length. Results describing the age-length relationship agree with our understanding of manatee biology. The new methods allow us to estimate age, with quantified uncertainty, for 98% of collected carcasses: 36% from ear bones, 62% from length.
Energy Technology Data Exchange (ETDEWEB)
Rabe, Claudio [Pontificia Univ. Catolica do Rio de Janeiro (PUC-Rio), RJ (Brazil); Syrio, Julio Cesar; Pizarro, Jorge Oscar de Sant' Anna [PETROBRAS, Rio de Janeiro, RJ (Brazil)
2004-07-01
This paper presents the work developed at PETROBRAS International to increase the natural gas reserves and production in Latin America. The results indicate that the company's new strategic focus has been providing an increase of its production of natural gas in 270%, in which daily production in September reached 84192 boed. The same happened with reserves in 2002, that increased in 37,2 billions m{sup 3}. This growth was mainly due to incorporation of Perez Conpanc and Petrolera Santa Fe. (author)
Visual Estimation of Bacterial Growth Level in Microfluidic Culture Systems.
Kim, Kyukwang; Kim, Seunggyu; Jeon, Jessie S
2018-02-03
Microfluidic devices are an emerging platform for a variety of experiments involving bacterial cell culture, and has advantages including cost and convenience. One inevitable step during bacterial cell culture is the measurement of cell concentration in the channel. The optical density measurement technique is generally used for bacterial growth estimation, but it is not applicable to microfluidic devices due to the small sample volumes in microfluidics. Alternately, cell counting or colony-forming unit methods may be applied, but these do not work in situ; nor do these methods show measurement results immediately. To this end, we present a new vision-based method to estimate the growth level of the bacteria in microfluidic channels. We use Fast Fourier transform (FFT) to detect the frequency level change of the microscopic image, focusing on the fact that the microscopic image becomes rough as the number of cells in the field of view increases, adding high frequencies to the spectrum of the image. Two types of microfluidic devices are used to culture bacteria in liquid and agar gel medium, and time-lapsed images are captured. The images obtained are analyzed using FFT, resulting in an increase in high-frequency noise proportional to the time passed. Furthermore, we apply the developed method in the microfluidic antibiotics susceptibility test by recognizing the regional concentration change of the bacteria that are cultured in the antibiotics gradient. Finally, a deep learning-based data regression is performed on the data obtained by the proposed vision-based method for robust reporting of data.
Visual Estimation of Bacterial Growth Level in Microfluidic Culture Systems
Directory of Open Access Journals (Sweden)
Kyukwang Kim
2018-02-01
Full Text Available Microfluidic devices are an emerging platform for a variety of experiments involving bacterial cell culture, and has advantages including cost and convenience. One inevitable step during bacterial cell culture is the measurement of cell concentration in the channel. The optical density measurement technique is generally used for bacterial growth estimation, but it is not applicable to microfluidic devices due to the small sample volumes in microfluidics. Alternately, cell counting or colony-forming unit methods may be applied, but these do not work in situ; nor do these methods show measurement results immediately. To this end, we present a new vision-based method to estimate the growth level of the bacteria in microfluidic channels. We use Fast Fourier transform (FFT to detect the frequency level change of the microscopic image, focusing on the fact that the microscopic image becomes rough as the number of cells in the field of view increases, adding high frequencies to the spectrum of the image. Two types of microfluidic devices are used to culture bacteria in liquid and agar gel medium, and time-lapsed images are captured. The images obtained are analyzed using FFT, resulting in an increase in high-frequency noise proportional to the time passed. Furthermore, we apply the developed method in the microfluidic antibiotics susceptibility test by recognizing the regional concentration change of the bacteria that are cultured in the antibiotics gradient. Finally, a deep learning-based data regression is performed on the data obtained by the proposed vision-based method for robust reporting of data.
A Pooled Mean Group Estimation of Capital Inflow and Growth in sub Saharan Africa
Directory of Open Access Journals (Sweden)
Chimere Okechukwu Iheonu
2017-09-01
Full Text Available This study empirically analysed the impact of capital inflow on growth in sub Saharan Africa employing the Pooled Mean Group estimator from the years 1985 to 2015. The study utilised Foreign Direct Investment (FDI, Official Development Assistance and Foreign Aid (ODA and Remittance (REM as indicators of capital inflow. Short run result indicates that the various forms of capital inflow do not have significant impact on growth but while FDI and REM were negatively related to growth, AID was positively related to growth. However, in the long run, FDI and AID have a positive and significant impact on growth while REM has a negative and significant impact on growth in sub Saharan Africa. The study concludes that planning and legislative lags are inferential from the insignificance of capital inflows on growth in the short run, while growth falls in the long run as a result of increase in labour’s income earned in diaspora. The study recommends that in the short run, economic policies should be tailored towards the development of technological based services while in the long run, government should create schemes for citizens in diaspora to participate in, to endear sector-specific economic activities as well as targeting FDI and AID as policy options to spur growth. Finally, specific capital inflow policy options should be employed as not all forms of capital inflow precipitates growth.
The Growth Points of Regional Economy and Regression Estimation for Branch Investment Multipliers
Directory of Open Access Journals (Sweden)
Nina Pavlovna Goridko
2018-03-01
Full Text Available The article develops the methodology of using investment multipliers to identify growth points for a regional economy. The paper discusses various options for the assessment of multiplicative effects caused by investments in certain sectors of the economy. All calculations are carried out on the example of economy of the Republic of Tatarstan for the period 2005–2015. The instrument of regression modeling using the method of least squares, permits to estimate sectoral and cross-sectoral investment multipliers in the economy of the Republic of Tatarstan. Moreover, this method allows to assess the elasticity of gross output of regional economy and its individual sectors depending on investment in various sectors of the economy. Calculations results allowed to identify three growth points of the economy of the Republic of Tatarstan. They are mining industry, manufacturing industry and construction. The success of a particular industry or sub-industry in a country or a region should be measured not only by its share in macro-system’s gross output or value added, but also by the multiplicative effect that investments in the industry have on the development of other industries, on employment and on general national or regional product. In recent years, the growth of the Russian was close to zero. Thus, it is crucial to understand the structural consequences of the increasing investments in various sectors of the Russian economy. In this regard, the problems solved in the article are relevant for a number of countries and regions with a similar economic situation. The obtained results can be applied for similar estimations of investment multipliers as well as multipliers of government spending, and other components of aggregate demand in various countries and regions to identify growth points. Investments in these growth points will induce the greatest and the most evident increment of the outcome from the macro-system’s economic activities.
ONODA, Tomoaki; YAMAMOTO, Ryuta; SAWAMURA, Kyohei; MURASE, Harutaka; NAMBO, Yasuo; INOUE, Yoshinobu; MATSUI, Akira; MIYAKE, Takeshi; HIRAI, Nobuhiro
2014-01-01
ABSTRACT We propose an approach of estimating individual growth curves based on the birthday information of Japanese Thoroughbred horses, with considerations of the seasonal compensatory growth that is a typical characteristic of seasonal breeding animals. The compensatory growth patterns appear during only the winter and spring seasons in the life of growing horses, and the meeting point between winter and spring depends on the birthday of each horse. We previously developed new growth curve equations for Japanese Thoroughbreds adjusting for compensatory growth. Based on the equations, a parameter denoting the birthday information was added for the modeling of the individual growth curves for each horse by shifting the meeting points in the compensatory growth periods. A total of 5,594 and 5,680 body weight and age measurements of Thoroughbred colts and fillies, respectively, and 3,770 withers height and age measurements of both sexes were used in the analyses. The results of predicted error difference and Akaike Information Criterion showed that the individual growth curves using birthday information better fit to the body weight and withers height data than not using them. The individual growth curve for each horse would be a useful tool for the feeding managements of young Japanese Thoroughbreds in compensatory growth periods. PMID:25013356
Plot size recommendations for biomass estimation in a midwestern old-growth forest
Martin A. Spetich; George R Parker
1998-01-01
The authors examine the relationship between disturbance regime and plot size for woody biomass estimation in a midwestern old-growth deciduous forest from 1926 to 1992. Analysis was done on the core 19.6 ac of a 50.1 ac forest in which every tree 4 in. d.b.h. and greater has been tagged and mapped since 1926. Five windows of time are comparedâ1926, 1976, 1981, 1986...
Pricing of reserves. Valuing system reserve capacity against spot prices in electricity markets
International Nuclear Information System (INIS)
Just, Sebastian; Weber, Christoph
2008-01-01
This paper models the interdependencies between markets for secondary reserve capacity and spot electricity to derive the pricing of reserves under equilibrium conditions. Starting with the indifference condition between offering in both markets, the reservation price is derived from the opportunity cost consideration and the unit commitment conditions in a fundamental interrelated market framework. The reserve market examined compares widely to the German market for secondary reserves, but the general approach may also be used to investigate other reserve markets. The approach explores and formalizes the influence of reserve capacity on the spot market supply function. A numerical solution procedure is provided to this non-trivial case of market interaction. The model is used to estimate the expected reservation price development over the last years in Germany. (author)
Estimates of genetic and environmental factors on growth and mortality in Karakul lambs
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Sayed Akbar Shiri
2016-04-01
Full Text Available Introduction Lamb production is the largest part of income in sheep industry. Therefore, the mortality rate of lambs is a key factor in profit of the sheep breeding. Mortality rate of lambs (or Lamb mortality rate in different breeds of sheep under different climatic conditions is varying from 15% to 50% and an average of 9% to 20% has been reported. Survival rate is a combination trait that is influenced by various factors such as management, weather condition, and behavior of dam and lamb, as well as genetic effects. Quantification of non-genetic effects on mortality rate can be useful in controlling lamb survival rate and increasing profitability of sheep breeding. Therefore, identification of genetic and environmental factors affecting the productive capacity of indigenous breeds in different area is the main priority that should be considered in breeding programmes. Therefore, the objective of this study was to estimate genetic and environmental factors of growth traits and mortality in Karakul lambs. To estimate the genetic and environmental parameters of Karakul lambs before weaning growth and mortality records of 4929 lambs from 207 rams and 1856 ewes at Sarakhs Karakul sheep breeding station, from 1994 to 2009 were used. Materials and Methods The data were used in this study included a total of 4929 record of lamb birth weight, 1 and 3 months of age, average daily gain from birth to weaning (growth traits before weaning and mortality rate of lambs from birth to 1, 2, 4, 8 and 14 weeks (mortality rate of lambs before weaning. Data were collected during the years 1994 to 2010 in karakul breeding station in Sarakhs. The data were edited and pedigree file and data file were prepared. Uni-variate animal model was used to estimate the genetic parameters as following: where is the vector of record, b is the vector of fixed effects (year, sex, type of birth, age of dam, a is the vector of direct additive genetic effects, m the vector of
Mineral Resources: Reserves, Peak Production and the Future
Directory of Open Access Journals (Sweden)
Lawrence D. Meinert
2016-02-01
Full Text Available The adequacy of mineral resources in light of population growth and rising standards of living has been a concern since the time of Malthus (1798, but many studies erroneously forecast impending peak production or exhaustion because they confuse reserves with “all there is”. Reserves are formally defined as a subset of resources, and even current and potential resources are only a small subset of “all there is”. Peak production or exhaustion cannot be modeled accurately from reserves. Using copper as an example, identified resources are twice as large as the amount projected to be needed through 2050. Estimates of yet-to-be discovered copper resources are up to 40-times more than currently-identified resources, amounts that could last for many centuries. Thus, forecasts of imminent peak production due to resource exhaustion in the next 20–30 years are not valid. Short-term supply problems may arise, however, and supply-chain disruptions are possible at any time due to natural disasters (earthquakes, tsunamis, hurricanes or political complications. Needed to resolve these problems are education and exploration technology development, access to prospective terrain, better recycling and better accounting of externalities associated with production (pollution, loss of ecosystem services and water and energy use.
An adaptive ARX model to estimate the RUL of aluminum plates based on its crack growth
Barraza-Barraza, Diana; Tercero-Gómez, Víctor G.; Beruvides, Mario G.; Limón-Robles, Jorge
2017-01-01
A wide variety of Condition-Based Maintenance (CBM) techniques deal with the problem of predicting the time for an asset fault. Most statistical approaches rely on historical failure data that might not be available in several practical situations. To address this issue, practitioners might require the use of self-starting approaches that consider only the available knowledge about the current degradation process and the asset operating context to update the prognostic model. Some authors use Autoregressive (AR) models for this purpose that are adequate when the asset operating context is constant, however, if it is variable, the accuracy of the models can be affected. In this paper, three autoregressive models with exogenous variables (ARX) were constructed, and their capability to estimate the remaining useful life (RUL) of a process was evaluated following the case of the aluminum crack growth problem. An existing stochastic model of aluminum crack growth was implemented and used to assess RUL estimation performance of the proposed ARX models through extensive Monte Carlo simulations. Point and interval estimations were made based only on individual history, behavior, operating conditions and failure thresholds. Both analytic and bootstrapping techniques were used in the estimation process. Finally, by including recursive parameter estimation and a forgetting factor, the ARX methodology adapts to changing operating conditions and maintain the focus on the current degradation level of an asset.
Jamie S. Sanderlin; Peter M. Waser; James E. Hines; James D. Nichols
2012-01-01
Metapopulation ecology has historically been rich in theory, yet analytical approaches for inferring demographic relationships among local populations have been few. We show how reverse-time multi-state captureÂrecapture models can be used to estimate the importance of local recruitment and interpopulation dispersal to metapopulation growth. We use 'contribution...
Mitchell, Niall A.; Ó'Ciardhá, Clifford T.; Frawley, Patrick J.
2011-08-01
This work details the estimation of the growth kinetics of paracetamol in ethanol solutions for cooling crystallisation processes, by means of isothermal seeded batch experiments. The growth kinetics of paracetamol crystals were evaluated in isolation, with the growth rate assumed to be size independent. Prior knowledge of the Metastable Zone Width (MSZW) was required, so that supersaturation ratios of 1.7-1.1 could be induced in solution without the occurrence of nucleation. The technique involved the utilisation of two in-situ Process Analytical Techniques (PATs), with a Focused Beam Reflectance Measurement (FBRM ®) utilised to ensure that negligible nucleation occurred and an Attenuated Total Reflectance-Fourier Transform Infrared (ATR-FTIR) probe employed for online monitoring of solute concentration. Initial Particle Size Distributions (PSDs) were used in conjunction with desupersaturation profiles to determine the growth rate as a function of temperature and supersaturation. Furthermore, the effects of seed loading and size on the crystal growth rate were investigated. A numerical model, incorporating the population balance equation and the method of moments, was utilised to describe the crystal growth process. Experimental parameters were compared to the model simulation, with the accuracy of the model validated by means of the final product PSDs and solute concentration.
Edixhoven, J. D.; Gupta, J.; Savenije, H. H. G.
2013-09-01
Phosphate rock (PR) is a finite mineral indispensible for fertilizer production and a major pollutant. High grade PR is obtained from deposits which took millions of years to form and are gradually being depleted. Over the past three years, global PR reserves as reported by US Geological Survey (USGS) have seen a massive increase, from 16 000 Mt PR in 2010 to 65 000 Mt PR in 2011. The bulk of this four-fold increase is based on a 2010 report by International Fertilizer Development Center (IFDC), which increased Moroccan reserves from 5700 Mt PR as reported by USGS, to 51 000 Mt PR, reported as upgraded ("beneficiated") concentrate. IFDC used a starkly simplified classification compared to the classification used by USGS and proposed that agreement should be reached on PR resource terminology which should be as simple as possible. The report has profoundly influenced the PR scarcity debate, shifting the emphasis from depletion to the pollution angle of the phosphate problem. Various analysts adopted the findings of IFDC and USGS, and argued that that following depletion of reserves, uneconomic deposits (resources and occurrences) will remain available which will extend the lifetime of available deposits to thousands of years. Given the near total dependence of food production on PR, data on PR deposits must be transparent, comparable, reliable and credible. Based on an in-depth literature review, we analyze (i) how IFDC's simplified terminology compares to international best practice in resource classification and whether it is likely to yield data that meets the abovementioned requirements; (ii) whether the difference between ore reserves and reserves as concentrate is sufficiently noted in the literature, and (iii) whether the IFDC report and its estimate of PR reserves and resources is reliable. We conclude that, while there is a global development toward common criteria in resource reporting, IFDC's definitions contravene this development and - due to their
Directory of Open Access Journals (Sweden)
Dan Armeanu
2015-03-01
Full Text Available In the current context of economic recovery and rebalancing, the necessity of modelling and estimating the potential output and output gap emerges in order to assess the quality and sustainability of economic growth, the monetary and fiscal policies, as well as the impact of business cycles. Despite the importance of potential GDP and the output gap, there are difficulties in reliably estimating them, as many of the models proposed in the economic literature are calibrated for developed economies and are based on complex macroeconomic relationships and a long history of robust data, while emerging economies exhibit high volatility. The object of this study is to develop a model in order to estimate the potential GDP and output gap and to assess the sustainability of projected growth using a multivariate filter approach. This trend estimation technique is the newest approach proposed by the economic literature and has gained wide acceptance with researchers and practitioners alike, while also being used by the IMF for Romania. The paper will be structured as follows. We first discuss the theoretical background of the model. The second section focuses on an analysis of the Romanian economy for the 1995–2013 time frame, while also providing a forecast for 2014–2017 and an assessment of the sustainability of Romania’s economic growth. The third section sums up the results and concludes.
SERIAL ULTRASOUND TO ESTIMATE FETAL GROWTH CURVES IN SOUTHERN TAMANDUA (TAMANDUA TETRADACTYLA).
Thompson, Rachel; Wolf, Tiffany M; Robertson, Heather; Colburn, Margarita Woc; Moreno, Alexis; Moresco, Anneke; Napier, Anne Elise; Nofs, Sally A
2017-06-01
From 2012 to 2015, 16 pregnancies were monitored by ultrasonography in nine tamanduas ( Tamandua tetradactyla ) housed in three zoological facilities. Sonographic measurements were recorded to establish fetal growth curves using thoracic and skull landmarks described for giant anteaters ( Myrmecophaga tridactyla ). All pregnancies resulted in the uncomplicated delivery of healthy offspring, thus gestational development was considered normal. These data may be used as a reference for normal fetal development with potential for estimating parturition date in the absence of breeding data.
Status of fossil fuel reserves
International Nuclear Information System (INIS)
Laherrere, J.
2005-01-01
Reserves represent the sum of past and future productions up to the end of production. In most countries the reserve data of fields are confidential. Therefore, fossil fuel reserves are badly known because the published data are more political than technical and many countries make a confusion between resources and reserves. The cumulated production of fossil fuels represents only between a third and a fifth of the ultimate reserves. The production peak will take place between 2020 and 2050. In the ultimate reserves, which extrapolate the past, the fossil fuels represent three thirds of the overall energy. This document analyses the uncertainties linked with fossil fuel reserves: reliability of published data, modeling of future production, comparison with other energy sources, energy consumption forecasts, reserves/production ratio, exploitation of non-conventional hydrocarbons (tar sands, extra-heavy oils, bituminous shales, coal gas, gas shales, methane in overpressure aquifers, methane hydrates), technology impacts, prices impact, and reserves growth. (J.S.)
Impact of water stress on growth reserves and re-growth of Themeda ...
African Journals Online (AJOL)
Four water stress treatments (T1 = 0–25%, T2 = 25–50%, T3 = 50–75% and T4 = 75–100% depletion of plant available water) were applied to the plants in pots in a glasshouse. The TNCC declined drastically after severe defoliation over all the water treatments (P < 0.05), in all the plant parts (P < 0.05) and for all the growth ...
Eaton, Mitchell J.; Link, William A.
2011-01-01
Estimating the age of individuals in wild populations can be of fundamental importance for answering ecological questions, modeling population demographics, and managing exploited or threatened species. Significant effort has been devoted to determining age through the use of growth annuli, secondary physical characteristics related to age, and growth models. Many species, however, either do not exhibit physical characteristics useful for independent age validation or are too rare to justify sacrificing a large number of individuals to establish the relationship between size and age. Length-at-age models are well represented in the fisheries and other wildlife management literature. Many of these models overlook variation in growth rates of individuals and consider growth parameters as population parameters. More recent models have taken advantage of hierarchical structuring of parameters and Bayesian inference methods to allow for variation among individuals as functions of environmental covariates or individual-specific random effects. Here, we describe hierarchical models in which growth curves vary as individual-specific stochastic processes, and we show how these models can be fit using capture–recapture data for animals of unknown age along with data for animals of known age. We combine these independent data sources in a Bayesian analysis, distinguishing natural variation (among and within individuals) from measurement error. We illustrate using data for African dwarf crocodiles, comparing von Bertalanffy and logistic growth models. The analysis provides the means of predicting crocodile age, given a single measurement of head length. The von Bertalanffy was much better supported than the logistic growth model and predicted that dwarf crocodiles grow from 19.4 cm total length at birth to 32.9 cm in the first year and 45.3 cm by the end of their second year. Based on the minimum size of females observed with hatchlings, reproductive maturity was estimated
Reserve selection with land market feedbacks.
Butsic, Van; Lewis, David J; Radeloff, Volker C
2013-01-15
How to best site reserves is a leading question for conservation biologists. Recently, reserve selection has emphasized efficient conservation: maximizing conservation goals given the reality of limited conservation budgets, and this work indicates that land market can potentially undermine the conservation benefits of reserves by increasing property values and development probabilities near reserves. Here we propose a reserve selection methodology which optimizes conservation given both a budget constraint and land market feedbacks by using a combination of econometric models along with stochastic dynamic programming. We show that amenity based feedbacks can be accounted for in optimal reserve selection by choosing property price and land development models which exogenously estimate the effects of reserve establishment. In our empirical example, we use previously estimated models of land development and property prices to select parcels to maximize coarse woody debris along 16 lakes in Vilas County, WI, USA. Using each lake as an independent experiment, we find that including land market feedbacks in the reserve selection algorithm has only small effects on conservation efficacy. Likewise, we find that in our setting heuristic (minloss and maxgain) algorithms perform nearly as well as the optimal selection strategy. We emphasize that land market feedbacks can be included in optimal reserve selection; the extent to which this improves reserve placement will likely vary across landscapes. Copyright © 2012 Elsevier Ltd. All rights reserved.
Vilela, Alejandra E.; Agüero, Paola R.; Ravetta, Damián; González-Paleo, Luciana
2016-01-01
Prosopis denudans, an extreme xerophyte shrub, is consumed by ungulates and threatened by firewood gathering, because it is one of the preferred species used by Mapuche indigenous people of Patagonia. In a scenario of uncontrolled use of vegetation, it is very difficult to develop a conservation plan that jointly protects natural resources and its users. We performed a field experiment to assess the impact of defoliation on growth, reproduction and stores of a wild population of P. denudans. We imposed four levels of defoliation (removal of 100, 66, 33 and 0% of leaves) and evaluated the short- and long-term (3 years) effects of this disturbance. Seasonal changes in shoot carbohydrates suggested that they support leaf-flush and blooming. Severely defoliated individuals also used root reserves to support growth and leaf-flush after clipping. Vegetative growth was not affected by defoliation history. Leaf mass area increased after the initial clipping, suggesting the development of structural defenses. The depletion of root reserves at the end of the first year affected inflorescence production the following spring. We conclude that P. denudans shrubs could lose up to one-third of their green tissues without affecting growth or inflorescence production. The removal of a higher proportion of leaves will diminish stores, which in turn, will reduce or completely prevent blooming and, therefore, fruit production the following seasons. Very few studies integrate conservation and plant physiology, and we are not aware, so far, of any work dealing with long-term plant carbon economy of a long-lived perennial shrub as an applied tool in conservation. These results might help the development of management strategies that consider both the use and the conservation of wild populations of P. denudans. PMID:27293747
Haskell, Craig A.; Beauchamp, David A.; Bollens, Stephen M.
2017-01-01
Juvenile salmon (Oncorhynchus spp.) use of reservoir food webs is understudied. We examined the feeding behavior of subyearling Chinook salmon (O. tshawytscha) and its relation to growth by estimating the functional response of juvenile salmon to changes in the density of Daphnia, an important component of reservoir food webs. We then estimated salmon growth across a broad range of water temperatures and daily rations of two primary prey, Daphnia and juvenile American shad (Alosa sapidissima) using a bioenergetics model. Laboratory feeding experiments yielded a Type-II functional response curve: C = 29.858 P *(4.271 + P)-1 indicating that salmon consumption (C) of Daphnia was not affected until Daphnia densities (P) were < 30 · L-1. Past field studies documented Daphnia densities in lower Columbia River reservoirs of < 3 · L-1 in July but as high as 40 · L-1 in August. Bioenergetics modeling indicated that subyearlings could not achieve positive growth above 22°C regardless of prey type or consumption rate. When feeding on Daphnia, subyearlings could not achieve positive growth above 20°C (water temperatures they commonly encounter in the lower Columbia River during summer). At 16–18°C, subyearlings had to consume about 27,000 Daphnia · day-1 to achieve positive growth. However, when feeding on juvenile American shad, subyearlings had to consume 20 shad · day-1 at 16–18°C, or at least 25 shad · day-1 at 20°C to achieve positive growth. Using empirical consumption rates and water temperatures from summer 2013, subyearlings exhibited negative growth during July (-0.23 to -0.29 g · d-1) and August (-0.05 to -0.07 g · d-1). By switching prey from Daphnia to juvenile shad which have a higher energy density, subyearlings can partially compensate for the effects of higher water temperatures they experience in the lower Columbia River during summer. However, achieving positive growth as piscivores requires subyearlings to feed at
North sea: a quarter of total's reserves (excluding the Middle East)
International Nuclear Information System (INIS)
Anon.
1995-01-01
In 1994, for the fifth successive year, Total increased its proven reserves of hydrocarbons which reach 4.3 Gboe (+ 6% compared to 1993). Outside the Middle East, the reserves show a development of 9% and reach the threshold of 2 Gboe. In 1994, Total's production of hydrocarbons reached 633,000 boe/d (+ 4%), despite a fall of 3% in oil production in the Middle East. Excluding the Middle East, production was increased to 345,000 boe/d (+ 12%), including 212,000 boe/d for gas (+ 20%). Exploration/production investments were 5.8 GF in 1994 (excluding labour) and the development program for reserves and production for the coming years is based on yearly investments of some 6 GF. Total's production in Europe, essentially in the North Sea, was 154,000 boe/d in 1994 (+ 12%). This zone has potential for significant growth for the group which has undertaken exploration surveys in the Western Shetlands and in Haltenbanken. In the British zone, the Dunbar field and its neighbour Ellon were brought into production in December 1994. In the Norwegian zone, the Froy field, was brought into production last June. In the Lille-Frigg field, whose production started in May, initial reserves are estimated at 6,7 Bcm of gas. Total Norge AS also has interests in the producing fields of Ekofisk, Frigg, East-Frigg, Heimdal, Sleipner East, Veslefrikk, Oseberg, Brage, in those of Sleipner West and Huldra (start-up scheduled for 1997) and in Troll (phase 1) which should be producing in 1996. In the Dutch zone, the K4b and K5a blocks brought into production last November hold reserves estimated at 20 Bcm; their production could reach 2 Bcm/year as from 1995. (authors). 1 tab., 1 photo
Tree Nonstructural Carbohydrate Reserves Across Eastern US Temperate Forests
Mantooth, J.; Dietze, M.
2015-12-01
Understanding the roles, importance, and dynamics of tree non-structural carbohydrates (NSCs) is currently an active area of research. The question of how the relationships between NSCs, growth, and mortality can be used to develop more accurate projections of forest dynamics is central to this research. To begin to address this question, we have asked an even more fundamental question: How much are trees allocating carbon to storage, in the form of NSCs, versus new growth? Ecological theory predicts that there should be trade-offs between different plant life history strategies provided that there are the carbon mass-balance constraints to enforce these trade-offs. Current data on tree NSCs lack the spatial and taxonomic extent required to properly address this question. Therefore, we established a network of forest inventory plots at ten sites across the eastern US and measured growth in adult trees using increment cores and repeat measures of diameter at breast height (DBH). Increment cores were also used to measure sapwood NSCs. We hypothesized that across the eastern US, shade tolerant species, e.g. Sugar Maple (Acer saccharum) have the largest NSC reserves and that shade intolerant species have the lowest reserves. We also hypothesized that NSC reserves increase with temperature and precipitation, as with growth, and that within species NSC reserves increase with growth rate. Initial analyses of tree NSCs indicates that trees of intermediate shade tolerance, e.g. Red Oak (Quercus rubra) have the highest concentrations of sapwood NSCs, and among the highest growth rates. Across the entire study region, NSC concentrations are positively correlated with tree size and growth rate. Within species, NSC concentrations are also positively correlated with growth rate. Across functional groups healthy individuals have significantly higher sapwood NSC concentrations than visibly stressed individuals. There are also significantly lower NSC concentrations in sapwood of
Effects of sex change on the implications of marine reserves for fisheries.
Chan, Neil C S; Connolly, Sean R; Mapstone, Bruce D
2012-04-01
Marine reserves have become widely used in biodiversity conservation and are increasingly proposed as fisheries management tools. Previous modeling studies have found that reserves may increase or decrease yields, depending on local environmental conditions and on the specific life-history traits of the fishery species. Sex-changing (female-to-male) fish are targets of some of the most important commercial and recreational fisheries in the world. The potential for disproportionate removal of the larger, older sex of such species requires new theory to facilitate our understanding of how reserves will affect the yields of surrounding fisheries, relative to fishes with separate sexes. We investigated this question by modeling the effects of marine reserves on a non-sex-changing and a sex-changing population. We used demographic parameter estimates for the common coral trout as a baseline, and we conducted extensive sensitivity analyses to determine how sustainable yields of sex-changing species are likely to be affected by reserves across a broad range of life-history parameters. Our findings indicate that fisheries for sex-changing species are unlikely to receive the same yield-enhancing benefit that non-sex-changing fisheries enjoy from marine reserves, and that often reserves tend to reduce sustainable yields for a given overall population size. Specifically, the increased egg production and high fertilization success within reserves is more than offset by the reduced egg production and fertilization success in the fished areas, relative to a system in which fishing mortality is distributed more evenly over the entire system. A key reason for this appears to be that fertilization success is reduced, on average, when males are unevenly distributed among subpopulations, as is the case when reserves are present. These findings suggests that, for sex-changing populations, reserves are more suited to rebuilding overfished populations and sustaining fishery viability
Directory of Open Access Journals (Sweden)
Yael Ehrlich
2017-11-01
Full Text Available The age of living massive olive trees is often assumed to be between hundreds and even thousands of years. These estimations are usually based on the girth of the trunk and an extrapolation based on a theoretical annual growth rate. It is difficult to objectively verify these claims, as a monumental tree may not be cut down for analysis of its cross-section. In addition, the inner and oldest part of the trunk in olive trees usually rots, precluding the possibility of carting out radiocarbon analysis of material from the first years of life of the tree. In this work we present a cross-section of an olive tree, previously estimated to be hundreds of years old, which was cut down post-mortem in 2013. The cross-section was radiocarbon dated at numerous points following the natural growth pattern, which was made possible to observe by viewing the entire cross-section. Annual growth rate values were calculated and compared between different radii. The cross-section also revealed a nearly independent segment of growth, which would clearly offset any estimations based solely on girth calculations. Multiple piths were identified, indicating the beginning of branching within the trunk. Different radii were found to have comparable growth rates, resulting in similar estimates dating the piths to the 19th century. The estimated age of the piths represent a terminus ante quem for the age of the tree, as these are piths of separate branches. However, the tree is likely not many years older than the dated piths, and certainly not centuries older. The oldest radiocarbon-datable material in this cross-section was less than 200 years old, which is in agreement with most other radiocarbon dates of internal wood from living olive trees, rarely older than 300 years.
Application of nuclear-geophysical methods to reserves estimation
International Nuclear Information System (INIS)
Bessonova, T.B.; Karpenko, I.A.
1980-01-01
On the basis of the analysis of reports dealing with calculations of mineral reserves considered are shortcomings in using nuclear-geophysical methods and in assessment of the reliability of geophysical sampling. For increasing efficiency of nuclear-geophysical investigations while prospecting ore deposits, it is advisable to introduce them widely instead of traditional geological sampling methods. For this purpose it is necessary to increase sensitivity and accuracy of radioactivity logging methods, to provide determination of certain elements in ores by these methods
DEFF Research Database (Denmark)
Seoane, Jose Miguel; Sin, Gürkan; Lardon, Laurent
2010-01-01
mathematical treatment, or wake-up pulses prior to the analysis.. Identifiability and sensitivity analysis were performed to confirm the robustness of the new approach for obtaining unique and accurate estimates of growth kinetic parameters. The new experimental design was applied to establish the. metabolic...
Spatial Rice Yield Estimation Based on MODIS and Sentinel-1 SAR Data and ORYZA Crop Growth Model
Directory of Open Access Journals (Sweden)
Tri D. Setiyono
2018-02-01
Full Text Available Crop insurance is a viable solution to reduce the vulnerability of smallholder farmers to risks from pest and disease outbreaks, extreme weather events, and market shocks that threaten their household food and income security. In developing and emerging countries, the implementation of area yield-based insurance, the form of crop insurance preferred by clients and industry, is constrained by the limited availability of detailed historical yield records. Remote-sensing technology can help to fill this gap by providing an unbiased and replicable source of the needed data. This study is dedicated to demonstrating and validating the methodology of remote sensing and crop growth model-based rice yield estimation with the intention of historical yield data generation for application in crop insurance. The developed system combines MODIS and SAR-based remote-sensing data to generate spatially explicit inputs for rice using a crop growth model. MODIS reflectance data were used to generate multitemporal LAI maps using the inverted Radiative Transfer Model (RTM. SAR data were used to generate rice area maps using MAPScape-RICE to mask LAI map products for further processing, including smoothing with logistic function and running yield simulation using the ORYZA crop growth model facilitated by the Rice Yield Estimation System (Rice-YES. Results from this study indicate that the approach of assimilating MODIS and SAR data into a crop growth model can generate well-adjusted yield estimates that adequately describe spatial yield distribution in the study area while reliably replicating official yield data with root mean square error, RMSE, of 0.30 and 0.46 t ha−1 (normalized root mean square error, NRMSE of 5% and 8% for the 2016 spring and summer seasons, respectively, in the Red River Delta of Vietnam, as evaluated at district level aggregation. The information from remote-sensing technology was also useful for identifying geographic locations with
Estimation of Genetic Parameters of Kleiber Ratio and Growth Traits in Kurdish Sheep
Directory of Open Access Journals (Sweden)
Davoud Ali Saghi
2016-11-01
Full Text Available Introduction Kurdish sheep breed is one of the most important native breeds of Iran. They are fat-tailed, large-sized, well adapted to the mountainous regions in northern Khorasan province and mainly raising for meat production under pastoral production system (28. Feed efficiency is a major component in the profitability of the small ruminant enterprise, because quality of range and pasture is low in poor environmental conditions in Iran. Growth rate and feed efficiency are two traits of great economic importance in sheep production and also Kleiber ratio has been suggested to be a useful indicator for these traits (2. There was no information regarding genetic parameters for growth traits in Kurdish sheep. Thus, the main objective of the present research was to estimate (covariance components and genetic parameters for pre- and post-weaning growth traits and Kleiber ratio in Kurdish sheep. Material and Methods In this study, the records of growth traits from 5144 lambs (from 161 rams and 1982 ewes were used. The data were collected during a 17-year period (1996–2013 in Kurdish sheep Breeding Station located in Shirvan city of northern Khorasan province. Traits investigated were average daily gain from birth to weaning (ADG0-3, average daily gain from weaning to six months of age (ADG3-6, average daily gain from six to nine months of age (ADG6-9, average daily gain from nine to twelve months of age (ADG9-12 and Kleiber ratios (KR defined as: KR1=ADG0-3/(BW30.75 KR2=ADG3-6/(BW60.75 KR3=ADG6-9/(BW90.75 KR4=ADG9-12/(BW120.75 Test of significance for the fixed effects to be included in the final functional model for each trait and calculation of least squares means was accomplished using GLM procedure of SAS software (24. The considered fixed effects were year of lambing (1996-2013, sex of lamb (male and female, type of birth (single and twin and age of ewe (1–7 years old. (Co variance components and genetic parameters were estimated applying
Directory of Open Access Journals (Sweden)
Nahid Hatam
2016-03-01
Full Text Available Increasing knowledge of people about health leads to raising the share of health expenditures in government budget continuously; although governors do not like this rise because of budget limitations. This study aimed to find the association between health expenditures and economic growth in ECO countries. We added health capital in Solow model and used the panel cointegration approach to show the importance of health expenditures in economic growth. For estimating the model, first we used Pesaran cross-sectional dependency test, after that we used Pesaran CADF unit root test, and then we used Westerlund panel cointegration test to show if there is a long-term association between variables or not. After that, we used chaw test, Breusch-Pagan test and Hausman test to find the form of the model. Finally, we used OLS estimator for panel data. Findings showed that there is a positive, strong association between health expenditures and economic growth in ECO countries. If governments increase investing in health, the total production of the country will be increased, so health expenditures are considered as an investing good. The effects of health expenditures in developing countries must be higher than those in developed countries. Such studies can help policy makers to make long-term decisions.
Hatam, Nahid; Tourani, Sogand; Homaie Rad, Enayatollah; Bastani, Peivand
2016-02-01
Increasing knowledge of people about health leads to raising the share of health expenditures in government budget continuously; although governors do not like this rise because of budget limitations. This study aimed to find the association between health expenditures and economic growth in ECO countries. We added health capital in Solow model and used the panel cointegration approach to show the importance of health expenditures in economic growth. For estimating the model, first we used Pesaran cross-sectional dependency test, after that we used Pesaran CADF unit root test, and then we used Westerlund panel cointegration test to show if there is a long-term association between variables or not. After that, we used chaw test, Breusch-Pagan test and Hausman test to find the form of the model. Finally, we used OLS estimator for panel data. Findings showed that there is a positive, strong association between health expenditures and economic growth in ECO countries. If governments increase investing in health, the total production of the country will be increased, so health expenditures are considered as an investing good. The effects of health expenditures in developing countries must be higher than those in developed countries. Such studies can help policy makers to make long-term decisions.
Hydrocarbon Reserves: Abundance or Scarcity
Energy Technology Data Exchange (ETDEWEB)
NONE
2005-07-01
IFP and the OAPEC jointly organize a regular international seminar dealing with world oil-related problems appearing in the news. For the first time, this seminar has been opened to oil and gas company specialists, service companies, research centers and independents. This year's theme concerns oil and gas reserves: are they abundant or are we headed towards the shortages announced by some experts? This theme is especially topical in that: oil and gas currently meet two thirds of world energy needs and almost completely dominate the transport sector; the reserves declared by the OAPEC countries account for nearly half of world reserves; the price of a barrel of oil went through the roof in 2004; world energy demand is growing fast and alternative sources of energy are far from ready to take over from oil and gas in the next few decades. Since the reserves correspond to the volume it is technically and economically viable to produce, the seminar has, of course, dealt with the technical and economic questions that arise in connection with exploration and production, but it has also considered changes in the geopolitical context. Presentations by the leading companies of the OAPEC countries and by the IFP group were completed by presentation from the International Energy Agency (IEA), the United States Geological Survey (USGS), the IHS Energy Group, Total and Gaz de France. This document gathers the transparencies of the following presentations: Hydrocarbon reserves in OAPEC members countries: current and future (M. Al-Lababidi); Non OAPEC liquid reserves and production forecasts (Y. Mathieu); World oil and gas resources and production outlook (K. Chew); Global investments in the upstream (F. Birol); Total's policy in the oil and gas sector (C. de Margerie); Gaz de France's policy in the oil and gas sector (J. Abiteboul); NOC/IOC's opportunities in OPEC countries (I. Sandrea); Relationships between companies, countries and investors: How they may impact on the growth
Hydrocarbon Reserves: Abundance or Scarcity
International Nuclear Information System (INIS)
2005-01-01
IFP and the OAPEC jointly organize a regular international seminar dealing with world oil-related problems appearing in the news. For the first time, this seminar has been opened to oil and gas company specialists, service companies, research centers and independents. This year's theme concerns oil and gas reserves: are they abundant or are we headed towards the shortages announced by some experts? This theme is especially topical in that: oil and gas currently meet two thirds of world energy needs and almost completely dominate the transport sector; the reserves declared by the OAPEC countries account for nearly half of world reserves; the price of a barrel of oil went through the roof in 2004; world energy demand is growing fast and alternative sources of energy are far from ready to take over from oil and gas in the next few decades. Since the reserves correspond to the volume it is technically and economically viable to produce, the seminar has, of course, dealt with the technical and economic questions that arise in connection with exploration and production, but it has also considered changes in the geopolitical context. Presentations by the leading companies of the OAPEC countries and by the IFP group were completed by presentation from the International Energy Agency (IEA), the United States Geological Survey (USGS), the IHS Energy Group, Total and Gaz de France. This document gathers the transparencies of the following presentations: Hydrocarbon reserves in OAPEC members countries: current and future (M. Al-Lababidi); Non OAPEC liquid reserves and production forecasts (Y. Mathieu); World oil and gas resources and production outlook (K. Chew); Global investments in the upstream (F. Birol); Total's policy in the oil and gas sector (C. de Margerie); Gaz de France's policy in the oil and gas sector (J. Abiteboul); NOC/IOC's opportunities in OPEC countries (I. Sandrea); Relationships between companies, countries and investors: How they may impact on the growth
Directory of Open Access Journals (Sweden)
Pavel Veselý
2006-01-01
Full Text Available The aim of the study was to determine the dynamics in the content of organic nutrients, ash and energy in dry matter of growths within the Mohelenská Serpentine Steppe National Nature Reserve (NPR, and to document their initial nutritive value before the intended grazing. Plant samples in 1995 and 1996 during the growing season in 14-days intervals from the area of 3 × 1 m2. Amounts of dry matter, fibre, nitrogen substances, fat and ashes were determined in growths according to the ANONYM (2001. Nitrogen-free extract substances (BNLV were determined by final calculating; BE, ME, NEL, NEV, PDIN and PDIE were calculated using the regression equations (VESELÝ and ZEMAN, 1995, 1997. Combining ratio (SP was calculated according to the relation: SP = PDIN (g/NEL (MJ. The dynamics of the contents of dry matter, organic nutrients, ashes and energy were assessed in the growth during the vegetation period and the dynamics was compared with standardized requirements of sheep (no pregnant ewe. Regression and correlation relations for nutrition value of the growths during vegetation period were calculated by use of mathematical-statistical analysis. Only statistically significantly (P<0.05 different parameters form the zero are presented in the paper. The content of dry matter in the growths culminated in summer months (places D8, E13, B17 and it was accompanied by depression in autumn months. After the highest content of crude protein, PDIN and PDIE recorded in spring months summer depression (August followed, this depression was partly balanced by autumn growth of vegetation. The content of ash in steppe growths increased during evaluated period. Similar tendency was registered for fat. Also the contents of fibre and BNLV linearly increased. The contents of nitrogen nutrients and energy corresponded with standardized requirements for sheep during whole vegetation period. Conversely the content of fibre highly exceeded the requirement except in spring
Fetal growth velocity and body proportion in the assessment of growth.
Hiersch, Liran; Melamed, Nir
2018-02-01
Fetal growth restriction implies failure of a fetus to meet its growth potential and is associated with increased perinatal mortality and morbidity. Therefore, antenatal detection of fetal growth restriction is of major importance in an attempt to deliver improved clinical outcomes. The most commonly used approach towards screening for fetal growth restriction is by means of sonographic fetal weight estimation, to detect fetuses small for gestational age, defined by an estimated fetal weight <10th percentile for gestational age. However, the predictive accuracy of this approach is limited both by suboptimal detection rate (as it may overlook non-small-for-gestational-age growth-restricted fetuses) and by a high false-positive rate (as most small-for-gestational-age fetuses are not growth restricted). Here, we review 2 strategies that may improve the diagnostic accuracy of sonographic fetal biometry for fetal growth restriction. The first strategy involves serial ultrasound evaluations of fetal biometry. The information obtained through these serial assessments can be interpreted using several different approaches including fetal growth velocity, conditional percentiles, projection-based methods, and individualized growth assessment that can be viewed as mathematical techniques to quantify any decrease in estimated fetal weight percentile, a phenomenon that many care providers assess and monitor routinely in a qualitative manner. This strategy appears promising in high-risk pregnancies where it seems to improve the detection of growth-restricted fetuses at increased risk of adverse perinatal outcomes and, at the same time, decrease the risk of falsely diagnosing healthy constitutionally small-for-gestational-age fetuses as growth restricted. Further studies are needed to determine the utility of this strategy in low-risk pregnancies as well as to optimize its performance by determining the optimal timing and interval between exams. The second strategy refers to the
US crude oil, natural gas, and natural gas liquids reserves: 1990 annual report
International Nuclear Information System (INIS)
1991-09-01
The primary focus of this report is to provide an accurate estimate of US proved reserves of crude oil, natural gas, and natural gas liquids. These estimates were considered essential to the development, implementation, and evaluation of natural energy policy and legislation. In the past, the government and the public relied upon industry estimates of proved reserves. These estimates were prepared jointly by the American Petroleum Institute (API) and the American Gas Association (AGA) and published in their annual report, Reserves of Crude Oil, Natural Gas Liquids, and Natural Gas in the United States and Canada. However, API and AGA ceased publication of reserves estimates after their 1979 report. By the mid-1970's, various federal agencies had separately established programs to collect data on, verify, or independently estimate domestic proved reserves of crude oil or natural gas. Each program was narrowly defined to meet the particular needs of the sponsoring agency. In response to recognized need for unified, comprehensive proved reserves estimates, Congress in 1977 required the Department of Energy to prepare such estimates. To meet this requirement, the EIA's reserves program was undertaken to establish a unified, verifiable, comprehensive, and continuing statistical series for proved reserves of crude oil and natural gas. The program was expanded to include proved reserves of natural gas liquids in the 1979 report. 36 refs., 11 figs., 16 tabs
Securities issues in reserves reporting
International Nuclear Information System (INIS)
Legg, M.B.
1997-01-01
Securities issues in oil and gas reserves reporting were discussed. Alberta requires specific information regarding important oil and gas properties, plants, facilities and installations. When preparing the reserves report, the following elements are important to consider: (1) the author of the report must be a registered professional engineer or registered professional geologist, (2) the report itself must be an engineering document, (3) the content of the report must be extensive, (4) it should be prepared in accordance with petroleum engineering and evaluation practices, and must include a summary of estimated net reserves
DEFF Research Database (Denmark)
Knudsen, Torben; Johansen, Torben
1990-01-01
Evidence is provided that regulation of the Na(+)-K+ pump activity in rat peritoneal mast cells occurs mainly through stimulation of the pump from inside the plasma membrane by sodium. It is demonstrated that there is a large reserve capacity for the exchange of intracellular sodium...... with extracellular potassium in these cells. The maximal pump activity was estimated to be 3230 pmol/10(6) cells per min and Km for extracellular potassium was 1.5 mM....
Microbial uptake of radiolabeled substrates: estimates of growth rates from time course measurements
International Nuclear Information System (INIS)
Li, W.K.W.
1984-01-01
The uptake of [ 3 H]glucose and a mixture of 3 H-labeled amino acids was measured, in time course fashion, in planktonic microbial assemblages of the eastern tropical Pacific Ocean. The average generation times of those portions of the assemblages able to utilize these substrates were estimated from a simple exponential growth model. Other workers have independently used this model in its integrated or differential form. A mathematical verification and an experimental demonstration of the equivalence of the two approaches are presented. A study was made of the size distribution of heterotrophic activity, using time course measurements. It was found that the size distribution and the effect of sample filtration before radiolabeling were dependent on time of incubation. In principle, it was possible to ascribe these time dependences to differences in th specific growth rate and initial standing stock of the microbial assemblages. 33 references
International Nuclear Information System (INIS)
Storto, G.; Gallicchio, R.; Maddalena, F.; Pellegrino, T.; Petretta, M.; Fiumara, G.; Cuocolo, A.
2015-01-01
Patients with hypertension may exhibit abnormal vasodilator capacity during pharmacological vasodilatation. We assessed coronary flow reserve (CFR) by sestamibi imaging in hypertensive patients with normal coronary vessels. Twenty-five patients with untreated mild essential hypertension and normal coronary vessels and 10 control subjects underwent dipyridamole-rest Tc-99m sestamibi imaging. Myocardial blood flow (MBF) was estimated by measuring first transit counts in pulmonary artery and myocardial counts from tomograhic images. CFR was expressed as the ratio of stress to rest MBF. Coronary vascular resistances (CVR) were computed as the ratio between mean arterial pressure and MBF. Estimated MBF at rest was not different in patients and controls (1.11±0.59 vs. 1.14±0.28 counts/pixel/s; P=0.87). Conversely, stress MBF was lower in patients than in controls (1.55±0.47 vs. 2.68±0.53 counts/pixel/s; P<0.001). Thus, CFR was reduced in patients compared to controls (1.61±0.58 vs. 2.43±0.62; P<0.001). Rest and stress CVR values were higher in patients (P<0.001), while stress-induced changes in CVR were not different (P=0.08) between patients (-51%) and controls (-62%). In the overall study population, a significant relation between CFR and stress-induced changes in CVR was observed (r=-0.86; P<0.001). Sestamibi imaging may detect impaired coronary vascular function in response to dipyridamole in patients with untreated mild essential hypertension and normal coronary arteries. A mild increase in arterial blood pressure does not affect baseline MBF, but impairs coronary reserve due to the amplified resting coronary resistances.
Reserves reporting for decision-making planning and control
International Nuclear Information System (INIS)
Higgins, G.
1992-01-01
This paper shows how the established Monte Carlo simulation approach to estimating hydrocarbon reserves can be expanded to provide the basis of a comprehensive valuation, planning and control system meeting all the reserve reporting requirements of an oil exploration and production company. The approach presented is also appropriate for other mining and extractive industries. The paper demonstrates how individual expectation curves can be modified to reflect both technically and commercially recoverable reserves and how these are in turn combined into the economic valuation, planning and control processes of an enterprise. Estimates across the full range of risk and reserves can be aggregated to provide a powerful planning tool that can be used to set corporate, divisional and individual objectives
Mercier, Lény; Panfili, Jacques; Paillon, Christelle; N'diaye, Awa; Mouillot, David; Darnaude, Audrey M.
2011-05-01
Accurate knowledge of fish age and growth is crucial for species conservation and management of exploited marine stocks. In exploited species, age estimation based on otolith reading is routinely used for building growth curves that are used to implement fishery management models. However, the universal fit of the von Bertalanffy growth function (VBGF) on data from commercial landings can lead to uncertainty in growth parameter inference, preventing accurate comparison of growth-based history traits between fish populations. In the present paper, we used a comprehensive annual sample of wild gilthead seabream ( Sparus aurata L.) in the Gulf of Lions (France, NW Mediterranean) to test a methodology improving growth modelling for exploited fish populations. After validating the timing for otolith annual increment formation for all life stages, a comprehensive set of growth models (including VBGF) were fitted to the obtained age-length data, used as a whole or sub-divided between group 0 individuals and those coming from commercial landings (ages 1-6). Comparisons in growth model accuracy based on Akaike Information Criterion allowed assessment of the best model for each dataset and, when no model correctly fitted the data, a multi-model inference (MMI) based on model averaging was carried out. The results provided evidence that growth parameters inferred with VBGF must be used with high caution. Hence, VBGF turned to be among the less accurate for growth prediction irrespective of the dataset and its fit to the whole population, the juvenile or the adult datasets provided different growth parameters. The best models for growth prediction were the Tanaka model, for group 0 juveniles, and the MMI, for the older fish, confirming that growth differs substantially between juveniles and adults. All asymptotic models failed to correctly describe the growth of adult S. aurata, probably because of the poor representation of old individuals in the dataset. Multi
Alaa F. Sheta; Amal Abdel-Raouf
2016-01-01
In this age of technology, building quality software is essential to competing in the business market. One of the major principles required for any quality and business software product for value fulfillment is reliability. Estimating software reliability early during the software development life cycle saves time and money as it prevents spending larger sums fixing a defective software product after deployment. The Software Reliability Growth Model (SRGM) can be used to predict the number of...
Geostatistics applied to estimation of uranium bearing ore reserves
International Nuclear Information System (INIS)
Urbina Galan, L.I.
1982-01-01
A computer assisted method for assessing uranium-bearing ore deposit reserves is analyzed. Determinations of quality-thickness, namely quality by thickness calculations of mineralization, were obtained by means of a mathematical method known as the theory of rational variables for each drill-hole layer. Geostatistical results were derived based on a Fortrand computer program on a DEC 20/40 system. (author)
Energy Technology Data Exchange (ETDEWEB)
Levey, R.A.; Finley, R.J.; Hardage, B.A.
1994-06-01
The Secondary Natural Gas Recovery (SGR): Targeted Technology Applications for Infield Reserve Growth is a joint venture research project sponsored by the Gas Research Institute (GRI), the US Department of Energy (DOE), the State of Texas through the Bureau of Economic Geology at The University of Texas at Austin, with the cofunding and cooperation of the natural gas industry. The SGR project is a field-based program using an integrated multidisciplinary approach that integrates geology, geophysics, engineering, and petrophysics. A major objective of this research project is to develop, test, and verify those technologies and methodologies that have near- to mid-term potential for maximizing recovery of gas from conventional reservoirs in known fields. Natural gas reservoirs in the Gulf Coast Basin are targeted as data-rich, field-based models for evaluating infield development. The SGR research program focuses on sandstone-dominated reservoirs in fluvial-deltaic plays within the onshore Gulf Coast Basin of Texas. The primary project research objectives are: To establish how depositional and diagenetic heterogeneities cause, even in reservoirs of conventional permeability, reservoir compartmentalization and hence incomplete recovery of natural gas. To document examples of reserve growth occurrence and potential from fluvial and deltaic sandstones of the Texas Gulf Coast Basin as a natural laboratory for developing concepts and testing applications. To demonstrate how the integration of geology, reservoir engineering, geophysics, and well log analysis/petrophysics leads to strategic recompletion and well placement opportunities for reserve growth in mature fields.
Hydrocarbon Reserves: Abundance or Scarcity
Energy Technology Data Exchange (ETDEWEB)
NONE
2005-07-01
impact on the growth of reserves and resources (H. Le Leuch); Additional reserves: the role of new technologies - A global perspective on EORIOR (G. Fries); - Updating reservoir models with dynamic data and uncertainty quantification: an integrated approach (F. Roggero); Seismic technology for the OAPEC countries (P. Canal); Exploration knowledge and technologies: impact of progress - Statistical results (N. Alazard); Stratigraphic modelling as a key to find new potentialities in exploration (D. Granjeon); Modelling hydrocarbon migration as a tool for reserve estimation (J-L. Rudkiewicz); The contribution of surface and near surface geology to hydrocarbon discoveries (S.M. Kumati); Contribution of the exploration activity in renewing reserves - The case of Algeria (R. Lounissi); Egypt's petroleum hydrocarbon potential (H. Hataba); Future of hydrocarbon reserves in Syria (T. Hemsh); Natural gas, the fuel of choice for decades to com (M.F. Chabrelie); The role and importance of Arab natural gas in world market (M. Al-Lababidi); LNG and GTL: two pathways for natural gas utilization (C. Cameron); Yet to find hydrocarbon potential (S. Al Menhali); Libyan context of hydrocarbon reserves: abundance or scarcity? (M. Elazi)
Alternative measures of the Federal Reserve Banks' cost of equity capital
Barnes, Michelle L.; Lopez, Jose A.
2005-01-01
The Monetary Control Act of 1980 requires the Federal Reserve System to provide payment services to depository institutions through the twelve Federal Reserve Banks at prices that fully reflect the costs a private-sector provider would incur, including a cost of equity capital (COE). Although Fama and French (1997) conclude that COE estimates are “woefully” and “unavoidably” imprecise, the Reserve Banks require such an estimate every year. We examine several COE estimates based on the Capital...
Directory of Open Access Journals (Sweden)
David H Williamson
Full Text Available No-take marine reserves (NTMRs are increasingly being established to conserve or restore biodiversity and to enhance the sustainability of fisheries. Although effectively designed and protected NTMR networks can yield conservation and fishery benefits, reserve effects often fail to manifest in systems where there are high levels of non-compliance by fishers (poaching. Obtaining reliable estimates of NTMR non-compliance can be expensive and logistically challenging, particularly in areas with limited or non-existent resources for conducting surveillance and enforcement. Here we assess the utility of density estimates and re-accumulation rates of derelict (lost and abandoned fishing line as a proxy for fishing effort and NTMR non-compliance on fringing coral reefs in three island groups of the Great Barrier Reef Marine Park (GBRMP, Australia. Densities of derelict fishing line were consistently lower on reefs within old (>20 year NTMRs than on non-NTMR reefs (significantly in the Palm and Whitsunday Islands, whereas line densities did not differ significantly between reefs in new NTMRs (5 years of protection and non-NTMR reefs. A manipulative experiment in which derelict fishing lines were removed from a subset of the monitoring sites demonstrated that lines re-accumulated on NTMR reefs at approximately one third (32.4% of the rate observed on non-NTMR reefs over a thirty-two month period. Although these inshore NTMRs have long been considered some of the best protected within the GBRMP, evidence presented here suggests that the level of non-compliance with NTMR regulations is higher than previously assumed.
Ramachandran, Andimuthu; Radhapriya, Parthasarathy
Restoration of a highly degraded forest, which had lost its natural capacity for regeneration, was attempted in the Nanmangalam Reserve Forest in Eastern Ghats of India. In field experiment, 12 native tree species were planted. The restoration included inoculation with a consortium of 5 native plant growth-promoting bacteria (PGPB), with the addition of small amounts of compost and a chemical fertilizer (NPK). The experimental fields were maintained for 1080 days. The growth and biomass varied depending on the plant species. All native plants responded well to the supplementation with the native PGPB. The plants such as Pongamia pinnata, Tamarindus indica, Gmelina arborea, Wrightia tinctoria, Syzygium cumini, Albizia lebbeck, Terminalia bellirica, and Azadirachta indica performed well in the native soil. This study demonstrated, by using native trees and PGPB, a possibility to restore the degraded forest.
Directory of Open Access Journals (Sweden)
Andimuthu Ramachandran
2016-01-01
Full Text Available Restoration of a highly degraded forest, which had lost its natural capacity for regeneration, was attempted in the Nanmangalam Reserve Forest in Eastern Ghats of India. In field experiment, 12 native tree species were planted. The restoration included inoculation with a consortium of 5 native plant growth-promoting bacteria (PGPB, with the addition of small amounts of compost and a chemical fertilizer (NPK. The experimental fields were maintained for 1080 days. The growth and biomass varied depending on the plant species. All native plants responded well to the supplementation with the native PGPB. The plants such as Pongamia pinnata, Tamarindus indica, Gmelina arborea, Wrightia tinctoria, Syzygium cumini, Albizia lebbeck, Terminalia bellirica, and Azadirachta indica performed well in the native soil. This study demonstrated, by using native trees and PGPB, a possibility to restore the degraded forest.
rights reserved Modelling Growth Kinetics of Klebsiella sp. FIRD 2
African Journals Online (AJOL)
ADOWIE PERE
... most toxic anthropogenic compounds deliberately introduced ... Due of its toxicity to marine organisms, the. International ... There are a lot of published papers describing ... The rate of bacterial growth and degradation can be represented as ...
Reserving by detailed conditioning on individual claim
Kartikasari, Mujiati Dwi; Effendie, Adhitya Ronnie; Wilandari, Yuciana
2017-03-01
The estimation of claim reserves is an important activity in insurance companies to fulfill their liabilities. Recently, reserving method of individual claim have attracted a lot of interest in the actuarial science, which overcome some deficiency of aggregated claim method. This paper explores the Reserving by Detailed Conditioning (RDC) method using all of claim information for reserving with individual claim of liability insurance from an Indonesian general insurance company. Furthermore, we compare it to Chain Ladder and Bornhuetter-Ferguson method.
International Nuclear Information System (INIS)
Hansen, M.V.
1981-01-01
The current low level of demand, compounded by rapidly rising costs and low prices, has caused a significant reduction in drilling for uranium in the United States, and the trend is likely to continue for a few more years. The effect on uranium reserves will be fewer additions to reserves because less exploration is being done. Further reductions will occur, especially in low-cost reserves, because of increasing costs, continuing depletion through production, and erosion through the high grading of deposits to fulfill previous contractual commitments. During the past several years, it has been necessary to increase the upper reserve cost level twice to compensate for rising costs. Rising costs are reducing the $15 reserves, the cost category corresponding most closely to the present market price, to an insignificant level. An encouraging factor related to US uranium reserves is that the US position internationally, as far as quantity is concerned, is not bad for the longer term. Also, there is a general opinion that US consumers would rather contract for domestic uranium than for foreign because of greater assurance of supply. Still another factor, nearly impossible to assess, is what effect rising costs in other countries will have on their uranium reserves. The annual conferences between the Grand Junction Area Office staff and major uranium companies provide a broad overview of the industry's perception of the future. It is not optimistic for the short term. Many companies are reducing their exploration and mining programs; some are switching to other more marketable mineral commodities, and a few are investing more heavily in foreign ventures. However, there is general optimism for the long term, and many predict a growth in demand in the mid-1980s. If the industry can survive the few lean years ahead, rising prices may restore its viability to former levels
Energy Technology Data Exchange (ETDEWEB)
Barreiro, S.; Rua, J.; Tomé, M.
2016-07-01
Aim of the study. To introduce and describe FlorNExT®, a free cloud computing application to estimate growth and yield of maritime pine (Pinus pinaster Ait.) even-aged stands in the Northeast of Portugal (NE Portugal). Area of study: NE Portugal. Material and methods: FlorNExT® implements a dynamic growth and yield modelling framework which integrates transition functions for dominant height (site index curves) and basal area, as well as output functions for tree and stand volume, biomass, and carbon content. Main results: FlorNExT® is freely available from any device with an Internet connection at: http://flornext.esa.ipb.pt/. Research highlights: This application has been designed to make it possible for any stakeholder to easily estimate standing volume, biomass, and carbon content in maritime pine stands from stand data, as well as to estimate growth and yield based on four stand variables: age, density, dominant height, and basal area. FlorNExT® allows planning thinning treatments. FlorNExT® is a fundamental tool to support forest mobilization at local and regional scales in NE Portugal. (Author)
Tuset, V. M.; García-Díaz, M. M.; González, J. A.; Lorente, M. J.; Lozano, I. J.
2005-08-01
The population biology of painted comber Serranus scriba (Linnaeus, 1758) of the Canary Islands coast was studied to estimate gonad morphology, sexuality, age and growth. Analysis of gonad organization and development revealed that it is a functional simultaneous hermaphrodite. Its anatomy and growth pattern of the reproductive cells is similar to that described in other species of the genus Serranus, although the sequence of vesicles appearing varies during vitellogenesis. Spawning season occurred from January to September with a peak in June. Individuals reached 50% maturity at 17.3 cm TL and 95% at 22.7 cm TL. Length-weight relationship was described by the following parameters: a = 0.01 and b = 3.10, being allometric positive. Age was determined from annuli in whole forming an opaque zone and a translucent zone in each annulus per year. The high percentage of otoliths with translucent zone during the annual cycle indicated that this species presents continuous growth throughout the year. Age range was 2-11 years for fish measuring 15.0-29.4 cm TL. This species is slow-growing and long lived. The growth parameters obtained were L∞ = 34.18 cm TL, k = 0.13 years -1, and to = -2.50 years. Otolith length was the best predictor of fish length, while the otolith weight was the best predictor of age.
Effect of massing on larval growth rate.
Johnson, Aidan P; Wallman, James F
2014-08-01
Estimation of minimum postmortem interval commonly relies on predicting the age of blowfly larvae based on their size and an estimate of the temperatures to which they have been exposed throughout their development. The majority of larval growth rate data have been developed using small larval masses in order to avoid excess heat generation. The current study collected growth rate data for larvae at different mass volumes, and assessed the temperature production of these masses, for two forensically important blow fly species, Chrysomya rufifacies and Calliphora vicina. The growth rate of larvae in a small mass, exposed to the higher temperatures equivalent to those experienced by large masses, was also assessed to determine if observed differences were due to the known temperature effects of maggot masses. The results showed that temperature production increased with increasing mass volume, with temperature increases of 11 °C observed in the large Ch. rufifacies masses and increases of 5 °C in the large C. vicina masses. Similarly, the growth rate of the larvae was affected by mass size. The larvae from small masses grown at the higher temperatures experienced by large masses displayed an initial delay in growth, but then grew at a similar rate to those larvae at a constant 23 °C. Since these larvae from masses of equivalent sizes displayed similar patterns of growth rate, despite differing temperatures, and these growth rates differed from larger masses exposed to the same temperatures, it can be concluded that larval growth rate within a mass may be affected by additional factors other than temperature. Overall, this study highlights the importance of understanding the role of massing in larval development and provides initial developmental data for mass sizes of two forensically important blowfly species commonly encountered in Australian forensic casework. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.
Estimation of time-varying growth, uptake and excretion rates from dynamic metabolomics data.
Cinquemani, Eugenio; Laroute, Valérie; Cocaign-Bousquet, Muriel; de Jong, Hidde; Ropers, Delphine
2017-07-15
Technological advances in metabolomics have made it possible to monitor the concentration of extracellular metabolites over time. From these data, it is possible to compute the rates of uptake and excretion of the metabolites by a growing cell population, providing precious information on the functioning of intracellular metabolism. The computation of the rate of these exchange reactions, however, is difficult to achieve in practice for a number of reasons, notably noisy measurements, correlations between the concentration profiles of the different extracellular metabolites, and discontinuties in the profiles due to sudden changes in metabolic regime. We present a method for precisely estimating time-varying uptake and excretion rates from time-series measurements of extracellular metabolite concentrations, specifically addressing all of the above issues. The estimation problem is formulated in a regularized Bayesian framework and solved by a combination of extended Kalman filtering and smoothing. The method is shown to improve upon methods based on spline smoothing of the data. Moreover, when applied to two actual datasets, the method recovers known features of overflow metabolism in Escherichia coli and Lactococcus lactis , and provides evidence for acetate uptake by L. lactis after glucose exhaustion. The results raise interesting perspectives for further work on rate estimation from measurements of intracellular metabolites. The Matlab code for the estimation method is available for download at https://team.inria.fr/ibis/rate-estimation-software/ , together with the datasets. eugenio.cinquemani@inria.fr. Supplementary data are available at Bioinformatics online. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com
ACR Appropriateness Criteria® growth disturbances - risk of intrauterine growth restriction.
Zelop, Carolyn M; Javitt, Marcia C; Glanc, Phyllis; Dubinsky, Theodore; Harisinghani, Mukesh G; Harris, Robert D; Khati, Nadia J; Mitchell, Donald G; Pandharipande, Pari V; Pannu, Harpreet K; Podrasky, Ann E; Shipp, Thomas D; Siegel, Cary Lynn; Simpson, Lynn; Wall, Darci J; Wong-You-Cheong, Jade J
2013-09-01
Fetal growth disturbances include fetuses at risk for intrauterine growth restriction. These fetuses may have an estimated fetal weight at less than the 10% or demonstrate a plateau of fetal growth with an estimated fetal growth greater than the 10%. Uteroplacental insufficiency may play a major role in the etiology of intrauterine growth restriction. Fetuses at risk for intrauterine fetal growth restriction are susceptible to the potential hostility of the intrauterine environment leading to fetal hypoxia and fetal acidosis. Fetal well-being can be assessed using biophysical profile, Doppler velocimetry, fetal heart rate monitoring, and fetal movement counting.Fetal growth disturbances include fetuses at risk for intrauterine growth restriction. These fetuses may have an estimated fetal weight at less than the 10% or demonstrate a plateau of fetal growth with an estimated fetal growth greater than the 10%. Uteroplacental insufficiency may play a major role in the etiology of intrauterine growth restriction. Fetuses at risk for intrauterine fetal growth restriction are susceptible to the potential hostility of the intrauterine environment leading to fetal hypoxia and fetal acidosis. Fetal well-being can be assessed using biophysical profile, Doppler velocimetry, fetal heart rate monitoring, and fetal movement counting.The ACR Appropriateness Criteria® are evidence-based guidelines for specific clinical conditions that are reviewed every two years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances where evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.
Deterministic estimation of crack growth rates in steels in LWR coolant environments
International Nuclear Information System (INIS)
Macdonald, D.D.; Lu, P.C.; Urquidi-Macdonald, M.
1995-01-01
In this paper, the authors extend the coupled environment fracture model (CEFM) for intergranular stress corrosion cracking (IGSCC) of sensitized Type 304SS in light water reactor heat transport circuits by incorporating steel corrosion, the oxidation of hydrogen, and the reduction of hydrogen peroxide, in addition to the reduction of oxygen (as in the original CEFM), as charge transfer reactions occurring on the external surfaces. Additionally, the authors have incorporated a theoretical approach for estimating the crack tip strain rate, and the authors have included a void nucleation model to account for ductile failure at very negative potentials. The key concept of the CEFM is that coupling between the internal and external environments, and the need to conserve charge, are the physical and mathematical constraints that determine the rate of crack advance. The model provides rational explanations for the effects of oxygen, hydrogen peroxide, hydrogen, conductivity, stress intensity, and flow velocity on the rate of crack growth in sensitized Type 304 in simulated LWR in-vessel environments. They propose that the CEFM can serve as the basis of a deterministic method for estimating component life times
Effects of sample size on estimates of population growth rates calculated with matrix models.
Directory of Open Access Journals (Sweden)
Ian J Fiske
Full Text Available BACKGROUND: Matrix models are widely used to study the dynamics and demography of populations. An important but overlooked issue is how the number of individuals sampled influences estimates of the population growth rate (lambda calculated with matrix models. Even unbiased estimates of vital rates do not ensure unbiased estimates of lambda-Jensen's Inequality implies that even when the estimates of the vital rates are accurate, small sample sizes lead to biased estimates of lambda due to increased sampling variance. We investigated if sampling variability and the distribution of sampling effort among size classes lead to biases in estimates of lambda. METHODOLOGY/PRINCIPAL FINDINGS: Using data from a long-term field study of plant demography, we simulated the effects of sampling variance by drawing vital rates and calculating lambda for increasingly larger populations drawn from a total population of 3842 plants. We then compared these estimates of lambda with those based on the entire population and calculated the resulting bias. Finally, we conducted a review of the literature to determine the sample sizes typically used when parameterizing matrix models used to study plant demography. CONCLUSIONS/SIGNIFICANCE: We found significant bias at small sample sizes when survival was low (survival = 0.5, and that sampling with a more-realistic inverse J-shaped population structure exacerbated this bias. However our simulations also demonstrate that these biases rapidly become negligible with increasing sample sizes or as survival increases. For many of the sample sizes used in demographic studies, matrix models are probably robust to the biases resulting from sampling variance of vital rates. However, this conclusion may depend on the structure of populations or the distribution of sampling effort in ways that are unexplored. We suggest more intensive sampling of populations when individual survival is low and greater sampling of stages with high
Effects of sample size on estimates of population growth rates calculated with matrix models.
Fiske, Ian J; Bruna, Emilio M; Bolker, Benjamin M
2008-08-28
Matrix models are widely used to study the dynamics and demography of populations. An important but overlooked issue is how the number of individuals sampled influences estimates of the population growth rate (lambda) calculated with matrix models. Even unbiased estimates of vital rates do not ensure unbiased estimates of lambda-Jensen's Inequality implies that even when the estimates of the vital rates are accurate, small sample sizes lead to biased estimates of lambda due to increased sampling variance. We investigated if sampling variability and the distribution of sampling effort among size classes lead to biases in estimates of lambda. Using data from a long-term field study of plant demography, we simulated the effects of sampling variance by drawing vital rates and calculating lambda for increasingly larger populations drawn from a total population of 3842 plants. We then compared these estimates of lambda with those based on the entire population and calculated the resulting bias. Finally, we conducted a review of the literature to determine the sample sizes typically used when parameterizing matrix models used to study plant demography. We found significant bias at small sample sizes when survival was low (survival = 0.5), and that sampling with a more-realistic inverse J-shaped population structure exacerbated this bias. However our simulations also demonstrate that these biases rapidly become negligible with increasing sample sizes or as survival increases. For many of the sample sizes used in demographic studies, matrix models are probably robust to the biases resulting from sampling variance of vital rates. However, this conclusion may depend on the structure of populations or the distribution of sampling effort in ways that are unexplored. We suggest more intensive sampling of populations when individual survival is low and greater sampling of stages with high elasticities.
DNIEPROVSKO-ORELSKIY NATURAL RESERVE AS THE REFUGIUM FOR HERPETOFAUNA IN PRIDNEPROVSK REGION
Directory of Open Access Journals (Sweden)
Missura A. N.
2011-11-01
Full Text Available Species diversity of herpetofauna of Dnieprovsko-Orel'skiy natural reserve was estimated based on long-term monitoring data; relative species’ abundance was determined as well. The retrospective estimation of amphibious populations in biogeocoenoses was performed for the period before and after creation of nature reserve. We also estimated turnover ratio of species between nature reserve biogeocoenoses and adjacent biotopes with high degree of recreation and urbanization. The data were incorporated into management plan for populations’ abundance stabilization and increasing.
Required reserves as a credit policy tool
Mimir, Yasin; Sunel, Enes; Taskin, Temel
2012-01-01
This paper conducts a quantitative investigation of the role of reserve requirements as a macroprudential policy tool. We build a monetary DSGE model with a banking sector in which (i) an agency problem between households and banks leads to endogenous capital constraints for banks in obtaining funds from households, (ii) banks are subject to time-varying reserve requirements that countercyclically respond to expected credit growth, (iii) households face cash-in-advance constraints, requiring ...
Directory of Open Access Journals (Sweden)
Paolo Casale
2009-09-01
Full Text Available Growth rates of the juvenile phase of loggerhead turtles (Caretta caretta were estimated for the first time in the Mediterranean Sea from capture-mark-recapture records. Thirty-eight turtles were released from Italian coasts and re-encountered after 1.0-10.9 years in the period 1986-2007. Their mean CCL (curved carapace length ranged from 32.5 to 82.0 cm and they showed variable growth rates, ranging from 0 to 5.97 cm/yr (mean: 2.5. The association between annual growth rate and three covariates (mean year, mean size and time interval was investigated through a non-parametric modelling approach. Only mean size showed a clear effect on growth rate, described by a monotonic declining curve. Variability indicates that factors not included in the model, probably individual-related ones, have an important effect on growth rates. Based on the monotonic decreasing growth function which indicates no growth spurt, a von Bertalanffy growth function was used to estimate the time required by turtles to grow within the observed size range. The results indicate that turtles would take 16-28 years to reach 66.5-84.7 cm CCL, the average nesting female sizes observed at the most important Mediterranean nesting sites, which can be considered an approximation of the size at maturity.
IGT calculates world reserves of fossil fuels
International Nuclear Information System (INIS)
Anon.
1986-01-01
The Institute of Gas Technology has published the IGT World Reserves Survey, giving their latest tabulation of world reserves of fossil fuels and uranium. The report contains 120 Tables and 41 Figures. Estimates are provided for proved reserves, resources, current production, and life indexes of the non-renewable energy sources of the US and of the world as a whole. World regional data are also provided in many cases. The data are summarized here. 2 figures, 5 tables
Directory of Open Access Journals (Sweden)
Mehrara Mohsen
2013-12-01
Full Text Available In the last few years, several studies have found an inverted-U relationship between per capita income and environmental degradation. This relationship, known as the environmental Kuznets curve (EKC, suggests that environmental degradation increases in the early stages of growth, but it eventually decreases as income exceeds a threshold level. However, this paper investigation relationship between per capita CO2 emission, growth economics and trade liberalization based on econometric techniques of unit root test, co-integration and a panel data set during the period 1960-1996 for BRICS countries. Data properties were analyzed to determine their stationarity using the LLC , IPS , ADF and PP unit root tests which indicated that the series are I(1. We find a cointegration relationship between per capita CO2 emission, growth economics and trade liberalization by applying Kao panel cointegration test. The evidence indi\tcates that in the long-run trade liberalization has a positive significant impact on CO2 emissions and impact of trade liberalization on emissions growth depends on the level of income Our findings suggest that there is a quadratic relationship between relationship between real GDP and CO2 emissions for the region as a whole. The estimated long-run coefficients of real GDP and its square satisfy the EKC hypothesis in all of studied countries. Our estimation shows that the inflection point or optimal point real GDP per capita is about 5269.4 dollars. The results show that on average, sample countries are on the positive side of the inverted U curve. The turning points are very low in some cases and very high in other cases, hence providing poor evidence in support of the EKC hypothesis. Thus, our findings suggest that all BRICS countries need to sacrifice economic growth to decrease their emission levels
Growth-induced axial buckling of a slender elastic filament embedded in an isotropic elastic matrix
O'Keeffe, Stephen G.
2013-11-01
We investigate the problem of an axially loaded, isotropic, slender cylinder embedded in a soft, isotropic, outer elastic matrix. The cylinder undergoes uniform axial growth, whilst both the cylinder and the surrounding elastic matrix are confined between two rigid plates, so that this growth results in axial compression of the cylinder. We use two different modelling approaches to estimate the critical axial growth (that is, the amount of axial growth the cylinder is able to sustain before it buckles) and buckling wavelength of the cylinder. The first approach treats the filament and surrounding matrix as a single 3-dimensional elastic body undergoing large deformations, whilst the second approach treats the filament as a planar, elastic rod embedded in an infinite elastic foundation. By comparing the results of these two approaches, we obtain an estimate of the foundation modulus parameter, which characterises the strength of the foundation, in terms of the geometric and material properties of the system. © 2013 Elsevier Ltd. All rights reserved.
Reserves in western basins: Part 1, Greater Green River basin
Energy Technology Data Exchange (ETDEWEB)
1993-10-01
This study characterizes an extremely large gas resource located in low permeability, overpressured sandstone reservoirs located below 8,000 feet drill depth in the Greater Green River basin, Wyoming. Total in place resource is estimated at 1,968 Tcf. Via application of geologic, engineering and economic criteria, the portion of this resource potentially recoverable as reserves is estimated. Those volumes estimated include probable, possible and potential categories and total 33 Tcf as a mean estimate of recoverable gas for all plays considered in the basin. Five plays (formations) were included in this study and each was separately analyzed in terms of its overpressured, tight gas resource, established productive characteristics and future reserves potential based on a constant $2/Mcf wellhead gas price scenario. A scheme has been developed to break the overall resource estimate down into components that can be considered as differing technical and economic challenges that must be overcome in order to exploit such resources: in other words, to convert those resources to economically recoverable reserves. Total recoverable reserves estimates of 33 Tcf do not include the existing production from overpressured tight reservoirs in the basin. These have estimated ultimate recovery of approximately 1.6 Tcf, or a per well average recovery of 2.3 Bcf. Due to the fact that considerable pay thicknesses can be present, wells can be economic despite limited drainage areas. It is typical for significant bypassed gas to be present at inter-well locations because drainage areas are commonly less than regulatory well spacing requirements.
Directory of Open Access Journals (Sweden)
Fernando Pérez-Rodríguez
2016-07-01
Full Text Available Aim of the study: To introduce and describe FlorNExT®, a free cloud computing application to estimate growth and yield of maritime pine (Pinus pinaster Ait. even-aged stands in the Northeast of Portugal (NE Portugal. Area of study: NE Portugal. Material and methods: FlorNExT® implements a dynamic growth and yield modelling framework which integrates transition functions for dominant height (site index curves and basal area, as well as output functions for tree and stand volume, biomass, and carbon content. Main results: FlorNExT® is freely available from any device with an Internet connection at: http://flornext.esa.ipb.pt/. Research highlights: This application has been designed to make it possible for any stakeholder to easily estimate standing volume, biomass, and carbon content in maritime pine stands from stand data, as well as to estimate growth and yield based on four stand variables: age, density, dominant height, and basal area. FlorNExT® allows planning thinning treatments. FlorNExT® is a fundamental tool to support forest mobilization at local and regional scales in NE Portugal. Keywords: forest management; maritime pine; forest modelling; knowledge transfer tool.
Wang, Jianming; Chen, Junran; Hu, Yunfeng; Hu, Hanyan; Liu, Guohua; Yan, Ruixiang
2017-10-01
For prediction of the shelf life of the mushroom Agaricus bisporus, the growth curve of the main spoilage microorganisms was studied under isothermal conditions at 2 to 22°C with a modified Gompertz model. The effect of temperature on the growth parameters for the main spoilage microorganisms was quantified and modeled using the square root model. Pseudomonas spp. were the main microorganisms causing A. bisporus decay, and the modified Gompertz model was useful for modelling the growth curve of Pseudomonas spp. All the bias factors values of the model were close to 1. By combining the modified Gompertz model with the square root model, a prediction model to estimate the shelf life of A. bisporus as a function of storage temperature was developed. The model was validated for A. bisporus stored at 6, 12, and 18°C, and adequate agreement was found between the experimental and predicted data.
DEFF Research Database (Denmark)
Solati, Zeinab; Jørgensen, Uffe; Eriksen, Jørgen
2017-01-01
Carbohydrate and Protein System across six harvests during the spring growth. RESULTS The estimated extractable protein [g kg−1 dry matter (DM)] defined as the easily available fractions B1+B2 was significantly higher in white clover and lucerne at all harvests while, if the more cell wall attached fraction B3...... for protein production purpose in a biorefinery due to its high extractable protein content per kg DM. In order to maximise the protein production capacity, harvest should take place during early growth due to a decline in protein extractability with maturity. The final economy of the concept will depend...
Development growth of uranium reserves during mining
International Nuclear Information System (INIS)
Giroux, M.
1989-01-01
According to the 1988 issue of the Nuclear Energy Agency report 'Uranium Resources, Production and Demand' (the Red Book), total uranium resources remained constant, and compare with those given in the 1986 issue. However, the low cost category of the Reasonably Assured Resources (RAR), that is to say potentially mineable reserves under present market conditions, presents a different picture. These show a decrease of 54 000 tonnes U, or about 3.5%, from the 1 January 1985 level. It seems insignificant until compared with what was removed from the ground - only a quarter of the 71 500 tonnes U of the low cost uranium that was extracted during 1985 and 1986 was renewed by the industry. This is probably related to the low level of exploration activity since 1983. Moreover, new uranium might be not as easy to find as some past discoveries have led us to believe. While in 1988 it appears there is enough low cost uranium to supply existing reactors, the picture quickly changes. From 1991 onwards, for 30 years' supply for existing reactors, uranium will have to come from RAR in the higher cost category. (author)
Substantiating the Incurred but not Reported Reserve
Directory of Open Access Journals (Sweden)
Georgeta Vintilã
2009-12-01
Full Text Available In order to handle past and future liability taken by insurance contracts concluded, any insurance company must constitute and maintain technical reserves. Substantiating technical reserves is done through actuarial methods and its over-evaluation or under-evaluation influence solvency and financial performance of the insurance companies, in the sense of reducing solvency through over-evaluating reserves and, respectively, influencing profit (hence of outstanding tax through under-evaluating reserves. An important reserve for insurance companies is represented by the incurred but not reported reserve, as it allows the estimation of the liability the company may confront in the future, generated by events occurred in the past, which are not currently known in the present but will be reported in the future.
Postnatal growth, age estimation and development of foraging ...
Indian Academy of Sciences (India)
Unknown
growth after the first year (Kunz and Stern 1995). The values of the lengths of forearm and epiphyseal gap dur- ing their linear phases of growth increased during the preflight period and decreased during the postflight period, and were reliable for deriving equations to esti- mate the age of young bats (e.g. Kunz and Robson ...
Directory of Open Access Journals (Sweden)
Miodrag Jovan Sreckovic
2017-05-01
Full Text Available Introduction : Psychological characteristics of patients, depression, stress and anxiety are recognized as important confounding risk factors for ischemic heart disease. However, the impact of psychological characteristics on coronary ischemia and vice versa remain poorly understood. Aim: To demonstrate the interplay of psychological characteristics, depression, stress and anxiety with coronary ischemia estimated with fractional flow reserve (FFR. Material and methods : From 2014 to 2016, 147 patients who were planned for FFR measurement were included in this study. Psychological characteristics of patients were evaluated using the Depression, Anxiety and Stress Scale 21 items (DASS 21 self-report questionnaire. Results : Comparing the FFR ischemic vs. FFR non-ischemic groups, a significant difference was observed regarding results achieved for the depression, anxiety and stress scales. Multivariate logistic regression analysis was used to model the correlation between FFR and the DAS scale. It was clear, when controlling for previous myocardial infarction, that FFR was significant in all analyses. However, when the Canadian Cardiovascular Society grading of angina pectoris (CCS class was entered in the model, FFR was not a significant predictor of anxiety, but was significant in other analysis. Conclusions : Higher degrees of the psychological characteristics depression, stress and anxiety were observed in the group of patients with coronary ischemia, corresponding to lower fractional flow values.
Too much of a good thing? Economic growth and human rights, 1960 to 2010.
Cole, Wade M
2017-09-01
Despite widespread belief in the benefits of economic growth, some scholars emphasize the potentially negative consequences of growth-and especially rapid growth-for social and political outcomes. Using data for 149 countries between 1960 and 2010, I analyze the effect of economic growth on fundamental human rights conditions. Dynamic random-effects and two-way fixed-effects estimators, both with and without instrumental variables, yield several conclusions. First, economic growth is causally prior to rights conditions. Second, economic growth has a modest positive effect on human rights, albeit with diminishing returns at high growth rates. Third, low-income countries account for much of this relationship: growth improves rights conditions for most low-income countries, but extremely rapid growth is inimical. Growth has little effect among middle-income countries, while for high-income countries the relationship is positive but not robust. I bring these findings to bear on long-standing debates between proponents and critics of modernization theory. Copyright © 2017 Elsevier Inc. All rights reserved.
Schmidt, Klaus; Schnaus, Anja
2016-01-01
This handbook presents the basic aspects of actuarial loss reserving. Besides the traditional methods, it also includes a description of more recent ones and a discussion of certain problems occurring in actuarial practice, like inflation, scarce data, large claims, slow loss development, the use of market statistics, the need for simulation techniques and the task of calculating best estimates and ranges of future losses. In property and casualty insurance the provisions for payment obligations from losses that have occurred but have not yet been settled usually constitute the largest item on the liabilities side of an insurer's balance sheet. For this reason, the determination and evaluation of these loss reserves is of considerable economic importance for every property and casualty insurer. Actuarial students, academics as well as practicing actuaries will benefit from this overview of the most important actuarial methods of loss reserving by developing an understanding of the underlying stochastic models...
An Online Evaluation of Operating Reserve for System Security
Le-Ren Chang-Chien; Yin-Juin Lin; Chin-Chung Wu
2007-01-01
Utilities use operating reserve for frequency regulation.To ensure that the operating frequency and system security are well maintained, the operating grid codes always specify that the reserve quantity and response rate should meet some prescribed levels. This paper proposes a methodology to evaluate system's contingency reserve for an isolated power network. With the presented algorithm to estimate system's frequency response characteristic, an online allocation of contingency reserve would...
Community College Estimated Growth: Fall 2010
Phillippe, Kent; Mullin, Christopher M.
2011-01-01
A survey from the American Association of Community Colleges (AACC) found that enrollment growth in fall 2010 slowed its pace at community colleges, increasing 3.2% from the previous year. This contrasts with more dramatic increases in recent years: more than 11% between fall 2008 and fall 2009, and nearly 17% between fall 2007 and fall 2009,…
US crude oil, natural gas, and natural gas liquids reserves 1996 annual report
Energy Technology Data Exchange (ETDEWEB)
NONE
1997-12-01
The EIA annual reserves report series is the only source of comprehensive domestic proved reserves estimates. This publication is used by the Congress, Federal and State agencies, industry, and other interested parties to obtain accurate estimates of the Nation`s proved reserves of crude oil, natural gas, and natural gas liquids. These data are essential to the development, implementation, and evaluation of energy policy and legislation. This report presents estimates of proved reserves of crude oil, natural gas, and natural gas liquids as of December 31, 1996, as well as production volumes for the US and selected States and State subdivisions for the year 1996. Estimates are presented for the following four categories of natural gas: total gas (wet after lease separation), nonassociated gas and associated-dissolved gas (which are the two major types of wet natural gas), and total dry gas (wet gas adjusted for the removal of liquids at natural gas processing plants). In addition, reserve estimates for two types of natural gas liquids, lease condensate and natural gas plant liquids, are presented. Also included is information on indicated additional crude oil reserves and crude oil, natural gas, and lease condensate reserves in nonproducing reservoirs. A discussion of notable oil and gas exploration and development activities during 1996 is provided. 21 figs., 16 tabs.
Cognitive Reserve Scale and ageing
Directory of Open Access Journals (Sweden)
Irene León
2016-01-01
Full Text Available The construct of cognitive reserve attempts to explain why some individuals with brain impairment, and some people during normal ageing, can solve cognitive tasks better than expected. This study aimed to estimate cognitive reserve in a healthy sample of people aged 65 years and over, with special attention to its influence on cognitive performance. For this purpose, it used the Cognitive Reserve Scale (CRS and a neuropsychological battery that included tests of attention and memory. The results revealed that women obtained higher total CRS raw scores than men. Moreover, the CRS predicted the learning curve, short-term and long-term memory, but not attentional and working memory performance. Thus, the CRS offers a new proxy of cognitive reserve based on cognitively stimulating activities performed by healthy elderly people. Following an active lifestyle throughout life was associated with better intellectual performance and positive effects on relevant aspects of quality of life.
The Nature and Use of Copper Reserve and Resource Data
Cox, Dennis P.; Wright, Nancy A.; Coakley, George J.
1981-01-01
Copper reserve, resource, and production data can be combined to produce disaggregated resource estimates and trends and, when combined with demand forecasts, can be used to predict future exploration and development requirements. Reserve estimates are subject to uncertainties due mainly to incomplete exploration and rapidly changing economic conditions. United States' reserve estimates in the past have been low mainly because knowledge of the magnitude of very large porphyry-copper deposits has been incomplete. Present estimates are considerably more reliable because mining firms tend to drill out deposits fully before mining and to release their reserve estimates to the public. The sum of reserves and past production yields an estimate of the total ore, total metal contained in ore, and average grade of ore originally in each of the deposits known in the United States. For most deposits, estimates of total copper in ore are low relative to the total copper in mineralized rock, and many estimates are strongly affected by the economic behavior of mining firms. A better estimate of the real distribution of copper contained in deposits can be obtained by combining past production data with resource estimates. Copper resource data are disaggregated into categories that include resources in undeveloped deposits similar to those mined in the past, resources in mines closed because of unfavorable economic conditions, resources in deep deposits requiring high-cost mining methods, arid resources in deposits located in areas where environmental restrictions have contributed to delays in development. The largest resource is located in the five largest porphyry deposits. These deposits are now being mined but the resources are not included in the present mining plan. Resources in this last category will not contribute to supply until some future time when ores presently being mined are depleted. A high correlation exists between total copper contained in deposits and annual
Directory of Open Access Journals (Sweden)
Stefano Schiavon
2010-01-01
Full Text Available Experimental data of feed consumption and composition, recorded over 5 consecutive short periods of growth from 30 crossbred male pigs divided 2 two groups and fed two restricted feeding regimes from 25 to 160 kg LW, were used to run a model in which a set of theoretical values, to describe the potential chemical growth of the pig, was preliminarily assumed. Simulated values of average daily gain (ADG and feed conversion ratio (FCR were the outputs. Estimates of protein mass at maturity (Pm, kg and relative growth rate (B, d-1 for each feeding regimes where successively obtained through an optimization procedure which has minimized the coefficients of variation of the differences between the estimates and the measurements of ADG and FCR. The very similar values of Pm (33.7 and 33.2 kg, and B (0.0104 and 0.0105 d-1, obtained for the two feed treatments suggested that these values can be used as operational data to describe the growth parameters of the experimental pigs used.
Directory of Open Access Journals (Sweden)
Voznyak Halyna V.
2017-06-01
Full Text Available The aim of the article is to define, determine and analyze the interrelationships between the budgetary decentralization and the economic growth of regions of Ukraine under conditions of reforming the power and financial resources. A statistical estimation of the influence of the budgetary decentralization on the economic growth of regions of Ukraine for 2015-2016 is carried out. The application of the panel data modeling allowed to build econometric models that made it possible to determine the ambiguous nature of the budgetary decentralization and identify key factors of its influence. It is shown that in terms of the income and expenditures the budgetary decentralization is positively associated with the economic growth of regions of Ukraine during the chosen time range of the study. The dynamic growth of the own revenues of local budgets is not a catalyst for the economic development of the regions. A strong negative effect of transfers on the dependent variable is confirmed. Among the variables included in the model and additionally characterizing the budgetary decentralization, the single tax and subsidies for the socio-economic development of individual territories attract attention. As a result of the study, the author justifies the need to minimize the transfer dependence of the regions at a simultaneous increasing of their own revenue base with local taxes and fees serving as a reliable basis for a long-term planning and development.
Estimating oil product demand in Indonesia using a cointegrating error correction model
International Nuclear Information System (INIS)
Dahl, C.
2001-01-01
Indonesia's long oil production history and large population mean that Indonesian oil reserves, per capita, are the lowest in OPEC and that, eventually, Indonesia will become a net oil importer. Policy-makers want to forestall this day, since oil revenue comprised around a quarter of both the government budget and foreign exchange revenues for the fiscal years 1997/98. To help policy-makers determine how economic growth and oil-pricing policy affect the consumption of oil products, we estimate the demand for six oil products and total petroleum consumption, using an error correction-cointegration approach, and compare it with estimates on a lagged endogenous model using data for 1970-95. (author)
International Nuclear Information System (INIS)
Pollard, P.C.; Moriarty, D.J.W.
1984-01-01
The rate of tritiated thymidine incorporation into DNA was used to estimate bacterial growth rates in aquatic environments. To be accurate, the calculation of growth rates has to include a factor for the dilution of isotope before incorporation. The validity of an isotope dilution analysis to determine this factor was verified in experiments reported here with cultures of a marine bacterium growing in a chemostat. Growth rates calculated from data on chemostat dilution rates and cell density agreed well with rates calculated by tritiated thymidine incorporation into DNA and isotope dilution analysis. With sufficiently high concentrations of exogenous thymidine, de novo synthesis of deoxythymidine monophosphate was inhibited, thereby preventing the endogenous dilution of isoope. The thymidine technique was also shown to be useful for measuring growth rates of mixed suspensions of bacteria growing anaerobically. Thymidine was incorporated into the DNA of a range of marine pseudomonads that were investigated. Three species did not take up thymidine. The common marine cyanobacterium Synechococcus species did not incorporate thymidine into DNA
Growth conditions of 0-group plaice
Cardoso, J.F.M.F.; Freitas, V.; de Paoli, H.; Witte, J.IJ.; van der Veer, H.W.
2016-01-01
Growth studies based on population-based growth estimates are limited by the fact that they do not take into account differences in age/size structure within the population. To overcome these problems, otolith microstructure analysis is often used to estimate individual growth. Here, we analyse
Reibaldi, Michele; Pulvirenti, Alfredo; Avitabile, Teresio; Bonfiglio, Vincenza; Russo, Andrea; Mariotti, Cesare; Bucolo, Claudio; Mastropasqua, Rodolfo; Parisi, Guglielmo; Longo, Antonio
2018-01-01
To assess the effect of topical antibiotic prophylaxis on postoperative endophthalmitis after intravitreal injection of anti-vascular endothelial growth factor agents. A systematic literature search was performed from inception to March 2016 using PubMed, Medline, Web of Science, Embase, and the Cochrane Library, to identify articles that reported cases of endophthalmitis after intravitreal injection of anti-vascular endothelial growth factor agents. We used a pooled analysis to estimate the incidence of cases of endophthalmitis who developed after injections performed with and without topical antibiotic prophylaxis. We used regression analysis to explore the effects of study characteristics on heterogeneity. From our search of electronic databases, we identified and screened 4,561 unique records. We judged 60 articles to have reported findings for cohorts of patients who met our inclusion criteria, (12 arms of randomized clinical trials, 11 prospective cohort studies, and 37 retrospective cohort studies), which included 244 cases of endophthalmitis and 639,391 intravitreal injections of anti-vascular endothelial growth factor agents. The final pooled estimate endophthalmitis proportions were 9/10,000 (95% confidence interval, 7/10,000-12/10,000) in the antibiotic-treated group and 3/10,000 (95% confidence interval, 2/10,000-5/10,000) in the untreated group. The estimated incidence of endophthalmitis with topical antibiotic prophylaxis was approximated three times the incidence without prophylaxis. Random effects regression showed that none of the study characteristics significantly affected the effect size in either group. Topical antibiotic after intravitreal injection of anti-vascular endothelial growth factor agents is associated with a higher risk of endophthalmitis.
Yan, Cai-Feng; Gessler, Arthur; Rigling, Andreas; Dobbertin, Matthias; Han, Xing-Guo; Li, Mai-He
2016-05-01
Most mistletoes are xylem-tapping hemiparasites, which derive their resources from the host's xylem solution. Thus, they affect the host's water relations and resource balance. To understand the physiological mechanisms underlying the mistletoe-host relationship, we experimentally removed Viscum album ssp. austriacum (Wiesb.) Vollmann from adult Pinus sylvestris L. host trees growing in a Swiss dry valley. We analyzed the effects of mistletoe removal over time on host tree growth and on concentrations of nonstructural carbohydrates (NSC) and nitrogen (N) in needles, fine roots and sapwood. In addition, we assessed the δ(13)C and δ(18)O in host tree rings. After mistletoe removal, δ(13)C did not change in newly produced tree rings compared with tree rings in control trees (still infected with mistletoe), but δ(18)O values increased. This pattern might be interpreted as a decrease in assimilation (A) and stomatal conductance (gs), but in our study, it most likely points to an inadequacy of the dual isotope approach. Instead, we interpret the unchanged δ(13)C in tree rings upon mistletoe removal as a balanced increase in A and gs that resulted in a constant intrinsic water use efficiency (defined as A/gs). Needle area-based concentrations of N, soluble sugars and NSC, as well as needle length, single needle area, tree ring width and shoot growth, were significantly higher in trees from which mistletoe was removed than in control trees. This finding suggests that mistletoe removal results in increased N availability and carbon gain, which in turn leads to increased growth rates of the hosts. Hence, in areas where mistletoe is common and the population is large, mistletoe management (e.g., removal) may be needed to improve the host vigor, growth rate and productivity, especially for relatively small trees and crop trees in xeric growth conditions. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.
Surging electricity demand growth bolsters outlook for natural gas
International Nuclear Information System (INIS)
Koen, A.D.
1994-01-01
Economic expansion and regulatory reform are combining to boost global opportunities for burning gas to generate electric power. Companies producing, marketing, or transporting gas are capitalizing on the improved outlook by seizing on synergistic roles in the power generation chain. Much of the improved outlook for gas stems from projected hearty increases in global demand for electricity. Bechtel Power Corp., estimates global power generation capacity during 1994--2003 will increase to as much as 1.2 billion kw, about 25% of which could be added by independent power production (IPPs). Since about 200 bcf of gas reserves producing about 20 MMcfd of gas is needed to fuel of a 100,000 kw electric generating station for 25 years, that adds up to a major growth opportunity for gas producers. The paper discusses the assessment of gas reserves, US power growth, the intent of the Energy Policy Act of 1992 (Epact), effects of Epact, gas industry response, power marketing units, synergistic possibilities, effects on US utilities, international power imperatives, non-US projects, funding good projects, and forecasting future developments
Total, accessible and reserve wind energy resources in Bulgaria
International Nuclear Information System (INIS)
Ivanov, P.; Trifonova, L.
1996-01-01
The article is a part of the international project 'Bulgaria Country Study to Address Climate Change Inventory of the Greenhouse Gases Emission and Sinks Alternative Energy Balance and Technology Programs' sponsored by the Department of Energy, US. The 'total' average annual wind resources in Bulgaria determined on the basis wind velocity density for more than 100 meteorological stations are estimated on 125 000 TWh. For the whole territory the theoretical wind power potential is about 14200 GW. The 'accessible' wind resources are estimated on about 62000 TWh. The 'reserve' (or usable) wind resources are determined using 8 velocity intervals for WECS (Wind Energy Conversion Systems) operation, number and disposition of turbines, and the usable (3%) part of the territory. The annual reserve resources are estimated at about 21 - 33 TWh. The 'economically beneficial' wind resources (EBWR) are those part of the reserve resources which could be included in the country energy balance using specific technologies in specific time period. It is foreseen that at year 2010 the EBWR could reach 0.028 TWh. 7 refs., 2 tabs., 1 fig
Effects of different international fiscal systems on reserves reporting
International Nuclear Information System (INIS)
McMichael, C.L.
1996-01-01
The effects of international fiscal systems on oil and gas reserves evaluation and reporting, was reviewed. The movement in reserves estimates with changing technical, political and economic conditions, was described. Difficulties associated with the evaluation and booking of reserves is largely due to the confusing duplication of terms. For example, explorationists refer to reserves as an undrilled prospect, while engineers refer to them as producing property. The financial analyst refers to reserves of a company, while governments refer to the reserves of the country. The importance of defining reserves with full knowledge of the specific regulations that govern the reporting of reserves externally, and the internal reporting requirements for business planning purposes, was stressed. 2 refs
Adequacy of Frequency Reserves for High Wind Power Generation
DEFF Research Database (Denmark)
Das, Kaushik; Litong-Palima, Marisciel; Maule, Petr
2017-01-01
In this article, a new methodology is developed to assess the adequacy of frequency reserves to handle power imbalances caused by wind power forecast errors. The goal of this methodology is to estimate the adequate volume and speed of activation of frequency reserves required to handle power...
Directory of Open Access Journals (Sweden)
Alberto Rojo-Alboreca
2015-12-01
Full Text Available Aim of study: To present the software utilities and explain how to use EucaTool®, a free cloud computing application developed to estimate the growth and production of seedling and clonal blue gum (Eucalyptus globulus Labill. plantations in Galicia (NW Spain.Area of study: Galicia (NW Spain.Material and methods: EucaTool® implements a dynamic growth and production model that is valid for clonal and non-clonal blue gum plantations in the region. The model integrates transition functions for dominant height (site index curves, number of stems per hectare (mortality function and basal area, as well as output functions for tree and stand volume, biomass and carbon content.Main results: EucaTool® can be freely accessed from any device with an Internet connection, from http://app.eucatool.com. In addition, useful information about the application is published on a related website: http://www.eucatool.com.Research highlights: The application has been designed to enable forest stakeholders to estimate volume, biomass and carbon content of forest plantations from individual trees, diameter classes or stand data, as well as to estimate growth and future production (indicating the optimal rotation age for maximum income by measurement of only four stand variables: age, number of trees per hectare, dominant height and basal area.Keywords: forest management; biomass; seedling; clones; blue gum; forest tool.
A General Business Model for Marine Reserves
Sala, Enric; Costello, Christopher; Dougherty, Dawn; Heal, Geoffrey; Kelleher, Kieran; Murray, Jason H.; Rosenberg, Andrew A.; Sumaila, Rashid
2013-01-01
Marine reserves are an effective tool for protecting biodiversity locally, with potential economic benefits including enhancement of local fisheries, increased tourism, and maintenance of ecosystem services. However, fishing communities often fear short-term income losses associated with closures, and thus may oppose marine reserves. Here we review empirical data and develop bioeconomic models to show that the value of marine reserves (enhanced adjacent fishing + tourism) may often exceed the pre-reserve value, and that economic benefits can offset the costs in as little as five years. These results suggest the need for a new business model for creating and managing reserves, which could pay for themselves and turn a profit for stakeholder groups. Our model could be expanded to include ecosystem services and other benefits, and it provides a general framework to estimate costs and benefits of reserves and to develop such business models. PMID:23573192
U.S. crude oil, natural gas, and natural gas liquids reserves 1995 annual report
Energy Technology Data Exchange (ETDEWEB)
NONE
1996-11-01
The EIA annual reserves report series is the only source of comprehensive domestic proved reserves estimates. This publication is used by the Congress, Federal and State agencies, industry, and other interested parties to obtain accurate estimates of the Nation`s proved reserves of crude oil, natural gas, and natural gas liquids. These data are essential to the development, implementation, and evaluation of energy policy and legislation. This report presents estimates of proved reserves of crude oil, natural gas, and natural gas liquids as of December 31, 1995, as well as production volumes for the US and selected States and State subdivisions for the year 1995. Estimates are presented for the following four categories of natural gas: total gas (wet after lease separation), nonassociated gas and associated-dissolved gas (which are the two major types of wet natural gas), and total dry gas (wet gas adjusted for the removal of liquids at natural gas processing plants). In addition, reserve estimates for two types of natural gas liquids, lease condensate and natural gas plant liquids, are presented. Also included is information on indicated additional crude oil reserves and crude oil, natural gas, and lease condensate reserves in nonproducing reservoirs. A discussion of notable oil and gas exploration and development activities during 1995 is provided. 21 figs., 16 tabs.
Halsteinli, Vidar; Kittelsen, Sverre A; Magnussen, Jon
2010-02-01
The performance of health service providers may be monitored by measuring productivity. However, the policy value of such measures may depend crucially on the accuracy of input and output measures. In particular, an important question is how to adjust adequately for case-mix in the production of health care. In this study, we assess productivity growth in Norwegian outpatient child and adolescent mental health service units (CAMHS) over a period characterized by governmental utilization of simple productivity indices, a substantial increase in capacity and a concurrent change in case-mix. We analyze the sensitivity of the productivity growth estimates using different specifications of output to adjust for case-mix differences. Case-mix adjustment is achieved by distributing patients into eight groups depending on reason for referral, age and gender, as well as correcting for the number of consultations. We utilize the nonparametric Data Envelopment Analysis (DEA) method to implicitly calculate weights that maximize each unit's efficiency. Malmquist indices of technical productivity growth are estimated and bootstrap procedures are performed to calculate confidence intervals and to test alternative specifications of outputs. The dataset consist of an unbalanced panel of 48-60 CAMHS in the period 1998-2006. The mean productivity growth estimate from a simple unadjusted patient model (one single output) is 35%; adjusting for case-mix (eight outputs) reduces the growth estimate to 15%. Adding consultations increases the estimate to 28%. The latter reflects an increase in number of consultations per patient. We find that the governmental productivity indices strongly tend to overestimate productivity growth. Case-mix adjustment is of major importance and governmental utilization of performance indicators necessitates careful considerations of output specifications. Copyright 2009 Elsevier Ltd. All rights reserved.
Brain reserve against physical disability progression over 5 years in multiple sclerosis.
Sumowski, James F; Rocca, Maria A; Leavitt, Victoria M; Meani, Alessandro; Mesaros, Sarlota; Drulovic, Jelena; Preziosa, Paolo; Habeck, Christian G; Filippi, Massimo
2016-05-24
The brain reserve hypothesis links larger maximal lifetime brain growth (MLBG, estimated with intracranial volume [ICV]) with lower risk for cognitive decline/dementia. We examined whether larger MLBG is also linked to less physical disability progression over 5 years in a prospective sample of treatment-naive patients with multiple sclerosis (MS). Physical disability was measured with the Expanded Disability Status Scale (EDSS) at baseline and 5-year follow-up in 52 treatment-naive Serbian patients with MS. MRI measured disease burden (cerebral atrophy, T2 lesion volume) and MLBG: a genetically determined, premorbid (established during adolescence, stable thereafter) patient characteristic estimated with ICV (adjusted for sex). Logistic regression tested whether MLBG (smaller vs larger) predicts disability progression (stable vs worsened) independently of disease burden. Disability progression was observed in 29 (55.8%) patients. Larger MLBG predicted lower risk for progression (odds ratio 0.13, 95% confidence interval 0.02-0.78), independently of disease burden. We also calculated absolute change in EDSS scores, and observed that patients with smaller MLBG showed worse EDSS change (0.91 ± 0.71) than patients with larger MLBG (0.42 ± 0.87). Larger MLBG was linked to lower risk for disability progression in patients with MS over 5 years, which is the first extension of the brain reserve hypothesis to physical disability. MLBG (ICV) represents a clinically available metric that may help gauge risk for future disability in patients with MS, which may advance the science and practice of early intervention. Potential avenues for future research are discussed. © 2016 American Academy of Neurology.
Energy Technology Data Exchange (ETDEWEB)
Craig, Joseph G.; Holsbeeck, Marnix van [Department of Radiology, Henry Ford Hospital, Detroit, MI (United States); Cody, Dianna D. [Department of Imaging Physics, University of Texas, M.D. Anderson Hospital, Houston, TX (United States)
2004-06-01
To explore how the size of the growth plate changes with age using three-dimensional (3D) models of the distal femoral and proximal tibial growth plates in pediatric patients. We retrospectively created 3D models of the normal unaffected distal femoral (n=20) and proximal tibial (n=10) growth plates in 14 patients (9 males, 5 females) age range 3.8-15.6 years who were referred for evaluation of premature partial closure of the growth plate or hyaline cartilage abnormality. All patients had one or more 3D fat-suppressed spoiled GRASS sequence from which models were made of normal growth plates. Total projected area was estimated from standardized maximum intensity projection (MIP) views, and volume was computed from the entire model. We also included the total projected area of the distal femur (n=7) or proximal tibia (n=8) in 11 patients (8 males, 3 females, 5-13 years) who had previously been evaluated for bone bridging. The 3D femoral and tibial growth plate anatomy was displayed. Femoral growth plate area varied from 804 mm{sup 2} to 3,463 mm{sup 2}. Femoral physeal cartilage volume varied from 2.1 cm{sup 3} to 12.6 cm{sup 3}. Tibial growth plate area varied from 736 mm{sup 2} to 3,026 mm{sup 2}. Tibial physeal cartilage volume varied from 1.9 cm{sup 3} to 13.2 cm{sup 3}. The growth plate area values appear to increase linearly with increasing age. (orig.)
Busquets-Vass, Geraldine; Newsome, Seth D.; Calambokidis, John; Serra-Valente, Gabriela; Jacobsen, Jeff K.; Aguíñiga-García, Sergio; Gendron, Diane
2017-01-01
Stable isotope analysis in mysticete skin and baleen plates has been repeatedly used to assess diet and movement patterns. Accurate interpretation of isotope data depends on understanding isotopic incorporation rates for metabolically active tissues and growth rates for metabolically inert tissues. The aim of this research was to estimate isotopic incorporation rates in blue whale skin and baleen growth rates by using natural gradients in baseline isotope values between oceanic regions. Nitrogen (δ15N) and carbon (δ13C) isotope values of blue whale skin and potential prey were analyzed from three foraging zones (Gulf of California, California Current System, and Costa Rica Dome) in the northeast Pacific from 1996–2015. We also measured δ15N and δ13C values along the lengths of baleen plates collected from six blue whales stranded in the 1980s and 2000s. Skin was separated into three strata: basale, externum, and sloughed skin. A mean (±SD) skin isotopic incorporation rate of 163±91 days was estimated by fitting a generalized additive model of the seasonal trend in δ15N values of skin strata collected in the Gulf of California and the California Current System. A mean (±SD) baleen growth rate of 15.5±2.2 cm y-1 was estimated by using seasonal oscillations in δ15N values from three whales. These oscillations also showed that individual whales have a high fidelity to distinct foraging zones in the northeast Pacific across years. The absence of oscillations in δ15N values of baleen sub-samples from three male whales suggests these individuals remained within a specific zone for several years prior to death. δ13C values of both whale tissues (skin and baleen) and potential prey were not distinct among foraging zones. Our results highlight the importance of considering tissue isotopic incorporation and growth rates when studying migratory mysticetes and provide new insights into the individual movement strategies of blue whales. PMID:28562625
US crude oil, natural gas, and natural gas liquids reserves
International Nuclear Information System (INIS)
1992-01-01
This report presents estimates of proved reserves of crude oil, natural gas, and natural gas liquids as of December 31, 1991, as well as production volumes for the United States, and selected States and State subdivisions for the year 1991. Estimates are presented for the following four categories of natural gas: total gas (wet after lease separation), its two major components (nonassociated and associated-dissolved gas), and total dry gas (wet gas adjusted for the removal of liquids at natural gas processing plants). In addition, two components of natural gas liquids, lease condensate and natural gas plant liquids, have their reserves and production data presented. Also included is information on indicated additional crude oil reserves and crude oil, natural gas, and lease condensate reserves in nonproducing reservoirs. A discussion of notable oil and gas exploration and development activities during 1991 is also presented
DEFF Research Database (Denmark)
Brock, Andreas Libonati; Kästner, M.; Trapp, Stefan
2017-01-01
NER. Formation of microbial mass can be estimated from the microbial growth yield, but experimental data is rare. Instead, we suggest using prediction methods for the theoretical yield based on thermodynamics. Recently, we presented the Microbial Turnover to Biomass (MTB) method that needs a minimum...... and using the released CO2 as a measure for microbial activity, we predicted a range for the formation of biogenic NER. For the majority of the pesticides, a considerable fraction of the NER was estimated to be biogenic. This novel approach provides a theoretical foundation applicable to the evaluation...
Zong, Xinnan; Li, Hui; Zhang, Yaqin; Wu, Huahong
2017-05-01
It is important to update weight-for-length/height growth curves in China and re-examine their performance in screening malnutrition. To develop weight-for-length/height growth curves for Chinese children and adolescents. A total of 94 302 children aged 0-19 years with complete sex, age, weight and length/height data were obtained from two cross-sectional large-scaled national surveys in China. Weight-for-length/height growth curves were constructed using the LMS method before and after average spermarcheal/menarcheal ages, respectively. Screening performance in prevalence estimates of wasting, overweight and obesity was compared between weight-for-height and body mass index (BMI) criteria based on a test population of 21 416 children aged 3-18. The smoothed weight-for-length percentiles and Z-scores growth curves with length 46-110 cm for both sexes and weight-for-height with height 70-180 cm for boys and 70-170 cm for girls were established. The weight-for-height and BMI-for-age had strong correlation in screening wasting, overweight and obesity in each age-sex group. There was no striking difference in prevalence estimates of wasting, overweight and obesity between two indicators except for obesity prevalence at ages 6-11. This set of smoothed weight-for-length/height growth curves may be useful in assessing nutritional status from infants to post-pubertal adolescents.
Triplet ultrasound growth parameters.
Vora, Neeta L; Ruthazer, Robin; House, Michael; Chelmow, David
2006-03-01
To create ultrasound growth curves for normal growth of fetal triplets using statistical methodology that properly accounts for similarities of growth of fetuses within a mother as well as repeated measurements over time for each fetus. In this longitudinal study, all triplet pregnancies managed at a single tertiary center from 1992-2004 were reviewed. Fetuses with major anomalies, prior selective reduction, or fetal demise were excluded. Data from early and late gestation in which there were fewer than 30 fetal measurements available for analysis were excluded. We used multilevel models to account for variation in growth within a single fetus over time, variations in growth between multiple fetuses within a single mother, and variations in fetal growth between mothers. Medians (50th), 10th, and 90th percentiles were estimated by the creation of multiple quadratic growth models from bootstrap samples adapting a previously published method to compute prediction intervals. Estimated fetal weight was derived from Hadlock's formula. One hundred fifty triplet pregnancies were identified. Twenty-seven pregnancies were excluded for the following reasons: missing records (23), fetal demise (3), and fetal anomaly (1). The study group consisted of 123 pregnancies. The gestational age range was restricted to 14-34 weeks. Figures and tables were developed showing medians, 10th and 90th percentiles for estimated fetal weight, femur length, biparietal diameter, abdominal circumference, and head circumference. Growth curves for triplet pregnancies were derived. These may be useful for identification of abnormal growth in triplet fetuses. III.
Widyatmoko, Didik; Burgman, Mark A.; Guhardja, Edi; Mogea, Johanis P.; Walujo, Eko B.; Setiadi, Dede
2005-09-01
Population status and demography of a population of the threatened lipstick palm Cyrtostachys renda in a peat swamp ecosystem of Kerumutan Reserve, Sumatra (one of the largest remaining populations) was documented at 16 different sites, covering a wide range of forest and habitat types, vegetation associations, and population sizes. Population sizes were dominated by suckers comprising 89% of the total population. Individuals with stem heights between 0 and 4 m (47.5%), stem diameters between 4 and 10 cm (82.0%), and leaf scar numbers between 0 and 60 (69.2%) dominated. Ages of individuals were estimated and used to fit a curvilinear relationship between age and stem height. Wild plants reach reproductive maturity within 25-30 years, or when they have stem heights in excess of 2.0 m, or when they have 15-25 leaf scars. They can survive more than 80 years. Cultivated plants appear to reproduce earlier and produce more seeds than wild plants. Individual growth was plant size-dependent with the adult stage being the most productive. Higher mortality was experienced by suckers, especially in continuously waterlogged conditions and locations with dense canopies. Sucker growth was faster than seedling growth, an adaptation that may allow the species to cope with periodically waterlogged conditions. Population abundances varied with habitat types; well-drained areas were the most suitable habitat. To conserve the most important remaining populations of the lipstick palm, it is crucial to protect well-drained sites in Kerumutan Reserve.
Is vocabulary growth influenced by the relations among words in a language learner's vocabulary?
Sailor, Kevin M
2013-09-01
Several recent studies have explored the applicability of the preferential attachment principle to account for vocabulary growth. According to this principle, network growth can be described by a process in which existing nodes recruit new nodes with a probability that is an increasing function of their connectivity within the existing network. The current study combined subjective estimates of the age of acquisition (AoA) and associations among words in a large corpus to estimate the organization of semantic knowledge at multiple points in vocabulary growth. Consistent with previous studies, the number of connections or relations among words followed a power law distribution in which relatively few words were highly connected with other words and most words were connected to relatively few words. In addition, the growth in the number of connections of a word was a linear function of its initial number of connections, and the ratio of connections to any two words was relatively constant over time. Finally, number of connections to known words was a reliable predictor of a word's AoA. All of these findings can be shown to be consistent with the preferential attachment principle. PsycINFO Database Record (c) 2013 APA, all rights reserved.
Dynamics of International Reserve Accumulation in Turkish Economy
Directory of Open Access Journals (Sweden)
Duygu Ayhan
2015-05-01
Full Text Available Many of the emerging market economies embody macroeconomic and structural vulnerabilities due to large deficits, high inflation, slowing growth and heavy reliance on short-term capital inflows. Therefore, accumulation of international reserve holdings has been frequently used by authorities to serve as an insurance against the volatility of the capital flows and strengthen the fragile nature of these economies. Turkish economy, classified as one of the most fragile of the emerging economies, has been experiencing a similar process of international reserve accumulation. The chronically high current account deficit and low savings rate boost the importance of international reserves. Thus, the aim of this paper is to investigate the determinants of international reserves in Turkey. The dataset covers the 2000-2013 period. Consequently, we find that the international reserve accumulation is mainly explained by current account balance, per capita income and past crisis experience.
Pattoura, P; Lefkaditou, E; Megalofonou, P
2015-03-01
The main goal of this study was to examine otolith microstructure and to estimate the age and growth of European hake Merluccius merluccius from the eastern Mediterranean Sea. One hundred and twenty-nine specimens ranging from 102 to 438 mm in total length (LT ) were used. Age estimations were based on the study of the otolith microstructure, which was revealed after grinding both frontal sides of otoliths. The enumerations of the daily growth increments (DGI) as well as their width (WDGI ) measurements were made on calibrated digital images. The number of DGI in otoliths ranged between 163 and 717. Four phases in the WDGI evolution were distinguished: (1) larval-juvenile pelagic phase, with an increasing trend in WDGI up to the 60th DGI, (2) settlement phase, with a short-term deceleration in WDGI between the 61st and 150th DGI, (3) juvenile demersal phase, characterized by a stabilization of WDGI from 151st to 400th DGI and (4) adult phase, with a decreasing trend in WDGI after the 400th DGI. Age, sex and month of formation were found to affect the WDGI in all phases, with the exception of age at the juvenile demersal phase. The power curve with intercept model described best the relationship of M. merluccius LT with age (TDGI ), according to Akaike criteria, revealing differences in growth between females [LT = 65 · 36(TDGI )(0 · 40) - 388 · 55] and males [LT = 69 · 32(TDGI )(0 · 37) - 352 · 88] for the sizes examined. The mean daily growth rates were 0·61 mm day(-1) for females and 0·52 mm day(-1) for males, resulting in an LT of 283 and 265 mm at the end of their first year of life. In comparison with previous studies on the Mediterranean Sea, the results of this study showed a greater growth rate, similar to results from tagging experiments and otolith microstructure analyses for M. merluccius in other geographic areas. © 2014 The Fisheries Society of the British Isles.
Estimation and Forecasting the Gross Domestic Product´s Growth Rate in Ecuador: a Short-term Vision
Directory of Open Access Journals (Sweden)
Yadier Alberto Torres−Sánchez
2016-12-01
Full Text Available Ecuador is the seventh largest economy in Latin America. From 2000 to 2012, the country has been expanding at an average rate of 1,15 % on a quarter over quarter basis, mostly due to a rise in exports. Ecuador´s economy is highly dependent on oil exports. In order to reach its full growth potential, the country needs to reduce its dependence on oil revenue; increase the tax base; achieve political stability and reduce the levels of poverty and inequality. The main objective of this research is specifically marked in estimate and forecast the Gross Domestic Product´s Growth Rate in Ecuador, applying for this Box – Jenkins´ Methodology for ARIMA models. It was obtained a forecast of 3,96 % approximately, that represents a logical result according with the time series.
Estimation and Forecasting the Gross Domestic Product´s Growth Rate in Ecuador: a Short-term Vision
Directory of Open Access Journals (Sweden)
Yadier Alberto Torres−Sánchez
2017-01-01
Full Text Available Ecuador is the seventh largest economy in Latin America. From 2000 to 2012, the country has been expanding at an average rate of 1,15 % on a quarter over quarter basis, mostly due to a rise in exports. Ecuador´s economy is highly dependent on oil exports. In order to reach its full growth potential, the country needs to reduce its dependence on oil revenue; increase the tax base; achieve political stability and reduce the levels of poverty and inequality. The main objective of this research is specifically marked in estimate and forecast the Gross Domestic Product´s Growth Rate in Ecuador, applying for this Box – Jenkins´ Methodology for ARIMA models. It was obtained a forecast of 3,96 % approximately, that represents a logical result according with the time series.
NASA Software Cost Estimation Model: An Analogy Based Estimation Model
Hihn, Jairus; Juster, Leora; Menzies, Tim; Mathew, George; Johnson, James
2015-01-01
The cost estimation of software development activities is increasingly critical for large scale integrated projects such as those at DOD and NASA especially as the software systems become larger and more complex. As an example MSL (Mars Scientific Laboratory) developed at the Jet Propulsion Laboratory launched with over 2 million lines of code making it the largest robotic spacecraft ever flown (Based on the size of the software). Software development activities are also notorious for their cost growth, with NASA flight software averaging over 50% cost growth. All across the agency, estimators and analysts are increasingly being tasked to develop reliable cost estimates in support of program planning and execution. While there has been extensive work on improving parametric methods there is very little focus on the use of models based on analogy and clustering algorithms. In this paper we summarize our findings on effort/cost model estimation and model development based on ten years of software effort estimation research using data mining and machine learning methods to develop estimation models based on analogy and clustering. The NASA Software Cost Model performance is evaluated by comparing it to COCOMO II, linear regression, and K- nearest neighbor prediction model performance on the same data set.
Rumen microbial growth estimation using in vitro radiophosphorous incorporation technique
International Nuclear Information System (INIS)
Bueno, Ives Claudio da Silva; Machado, Mariana de Carvalho; Cabral Filho, Sergio Lucio Salomon; Gobbo, Sarita Priscila; Vitti, Dorinha Miriam Silber Schmidt; Abdalla, Adibe Luiz
2002-01-01
Rumen microorganisms are able to transform low biological value nitrogen of feed stuff into high quality protein. To determine how much microbial protein that process forms, radiomarkers can be used. Radiophosphorous has been used to mark microbial protein, as element P is present in all rumen microorganisms (as phospholipids) and the P:N ratio of rumen biomass is quite constant. The aim of this work was to estimate microbial synthesis from feedstuff commonly used in ruminant nutrition in Brazil. Tested feeds were fresh alfalfa, raw sugarcane bagasse, rice hulls, rice meal, soybean meal, wheat meal, Tifton hay, leucaena, dehydrated citrus pulp, wet brewers' grains and cottonseed meal. 32 P-labelled phosphate solution was used as marker for microbial protein. Results showed the diversity of feeds by distinct quantities of nitrogen incorporated into microbial mass. Low nutrient availability feeds (sugarcane bagasse and rice hulls) promoted the lowest values of incorporated nitrogen. Nitrogen incorporation showed positive relationship (r=0.56; P=0.06) with the rate of degradation and negative relationship (r=-0.59; P<0.05) with fiber content of feeds. The results highlight that easier fermentable feeds (higher rates of degradation) and/or with lower fiber contents promote a more efficient microbial growth and better performance for the host animal. (author)
Rumen microbial growth estimation using in vitro radiophosphorous incorporation technique
Energy Technology Data Exchange (ETDEWEB)
Bueno, Ives Claudio da Silva; Machado, Mariana de Carvalho; Cabral Filho, Sergio Lucio Salomon; Gobbo, Sarita Priscila; Vitti, Dorinha Miriam Silber Schmidt; Abdalla, Adibe Luiz [Centro de Energia Nuclear na Agricultura (CENA), Piracicaba, SP (Brazil)
2002-07-01
Rumen microorganisms are able to transform low biological value nitrogen of feed stuff into high quality protein. To determine how much microbial protein that process forms, radiomarkers can be used. Radiophosphorous has been used to mark microbial protein, as element P is present in all rumen microorganisms (as phospholipids) and the P:N ratio of rumen biomass is quite constant. The aim of this work was to estimate microbial synthesis from feedstuff commonly used in ruminant nutrition in Brazil. Tested feeds were fresh alfalfa, raw sugarcane bagasse, rice hulls, rice meal, soybean meal, wheat meal, Tifton hay, leucaena, dehydrated citrus pulp, wet brewers' grains and cottonseed meal. {sup 32} P-labelled phosphate solution was used as marker for microbial protein. Results showed the diversity of feeds by distinct quantities of nitrogen incorporated into microbial mass. Low nutrient availability feeds (sugarcane bagasse and rice hulls) promoted the lowest values of incorporated nitrogen. Nitrogen incorporation showed positive relationship (r=0.56; P=0.06) with the rate of degradation and negative relationship (r=-0.59; P<0.05) with fiber content of feeds. The results highlight that easier fermentable feeds (higher rates of degradation) and/or with lower fiber contents promote a more efficient microbial growth and better performance for the host animal. (author)
STATISTICAL ESTIMATION OF THE GREEN GROWTH IN UKRAINE
Directory of Open Access Journals (Sweden)
G. Yeliseyeva
2013-10-01
Full Text Available A set of indicators proposed by the OECD that assesses economic opportunities arising from the green growth as well as helps policy-making concerning environmental issues, in particular indicators on technology and innovation, production and consumption of environmental goods and services, environmentally related prices and transfers as well as associated to green growth financial flows, have been studied in detail in this article. The results of the comparison analysis of the application of the abovementioned indicators by the Czech Republic, Denmark, Germany, the Netherlands and Korea are presented in the article. Based on the performed analysis possible application of the proposed by OECD set of indicators to the Ukraine’s national context has been explored. Proposed set of green growth indicators can be applied in Ukraine, however further development is required to enhance the statistical data accounting and availability. Among the main challenges to the implementation of such system in Ukraine is the lack of data as well as medium compliance of the Ukraine’s Environmental Accounts with the European regulation, which complicates the development of national policy towards green economy and the international comparison.
International Nuclear Information System (INIS)
Thomas, S.R.; Gelfand, M.J.; Burns, G.S.; Purdom, R.C.; Kereiakes, J.G.; Maxon, H.R.
1983-01-01
Quantitative conjugate-view external counting techniques were applied to estimate the radiation dose to the liver, spleen, and metaphyseal growth complexes (distal femur and proximal tibia) for ten pediatric patients undergoing gallium-67 scanning procedures. The effective half-life of Ga 67 in these organs was approximately 78 hours. The dose per unit of administered activity for the liver and spleen was between 0.3 and 4.0 rad/mCi (0.08 to 1.08 Gy/GBq) and 0.5 and 7.0 rad/mCi (0.13 to 1.89 Gy/GBq), respectively. For the metaphyseal growth plates, the range was 2.3 to 14.3 rad/mCi (0.62 to 3.86 Gy/GBq)
Energy Technology Data Exchange (ETDEWEB)
Merkulov, N.E.; Lysenkov, P.P.
1981-01-01
Estimated are the reliable predicted reserves of oil and gas of the Chechen-Ingushetia by methods of probability calculations. Calculations were made separately for each oil-bearing lithologic-stratigraphic horizon. The computation results are summarized in a table, and graphs are constructed.
Deterministic claims reserving in short-term insuarance contracts ...
African Journals Online (AJOL)
Claims reserving for general insurance business has developed significantly over the recent past. This has been occasioned by the growth of the insurance market, with the risk underwriting process becoming more and more complex. New insurance products have been developed that cater for the more specific needs of ...
Bontemps , Jean-Daniel; Esper , Jan
2011-01-01
International audience; Dendrochronological methods have greatly contributed to the documentation of past long-term trends in forest growth. These methods primarily focus on the high-frequency signals of tree ring chronologies. They require the removal of the ageing trend in tree growth, known as 'standardisation' or 'detrending', as a prerequisite to the estimation of such trends. Because the approach is sequential, it may however absorb part of the low-frequency historical signal. In this s...
Scholz, R. W.; Wellmer, F.-W.
2015-01-01
Several recent papers predict a scarcity of phosphate reserves in the near future. The paper by Edixhoven et al. (2014), for instance, expresses the doubts about whether the upward estimate of reserves by the IFDC (2010) and the USGS (2010) provide an accurate, reliable, and comparable picture, as they are based on reports that do not clearly differentiate between phosphate ore and phosphate products (i.e., marketable phosphate rock concentrate). Further the indistinct use of the terms reserves and resources is criticized. Edixhoven et al. ask for a differentiated inventory of world phosphate reserves including "guidelines which determine the appropriate drill hole distances." The claim that humanity is on the safe side with respect to future phosphate is supply is doubted as the validity of the IFDC's upgrading of the Moroccan data to 50 Gt phosphate is questioned. The present paper identifies and discusses basic conceptual errors of the paper by Edixhoven et al. and related papers that predict a short or mid-term phosphorus scarcity. These include the non-acknowledgment of the dynamic nature of reserves (which depends on price, technology, and innovation for exploiting low-grade deposits, etc.), the mixing of finiteness and staticness of the ultimate recoverable resources (i.e., phosphorus that may be mined economically in the long-term future), the improper use of the Hubbert analysis (which, e.g., simply uses the USGS estimates of reserves as a substitute of an estimate of ultimate recoverable resources) and the geostatistical naive/unprofessional demand for fixed drilling plans to assess reserves. We reconstruct the IFDC and USGS estimates and conclude that there is no evidence for considering the 50 Gt phosphate concentrate as an unreasonable estimate for Moroccan reserves. However, the partial mixing of different units (e.g., phosphate ore and phosphate concentrate or marketable product) in the USGS data may be avoided by improving the data base and using
International Nuclear Information System (INIS)
Laherrere, J.
1998-01-01
The oil geologists worry about the oil reserves. An inventory of the oil resources estimations was carried out by the OECD-IEA. Some of the subjects covered by this inventory are commented with the arguments of the two schools : optimists and pessimists. The analysis takes account of the influence of the costs and the offshore technology. (A.L.B.)
THE EFFECT OF CHANGES IN RESERVE REQUIREMENTS DURING THE 1930s:
Thomas Mayer; Thomas F. Cargill
2004-01-01
The differential response of cash reserves of member banks and nonmember banks not subject to the 1936-37 increase in reserve requirements is estimated to determine whether the 1937-38 recession was caused by the increase in reserve requirements. We identify 17 states that maintained constant reserve requirements from June 1934 to June 1941. While member banks increased their cash reserve ratios relative to nonmember banks, the magnitude of the adjustment is too small to have contributed to t...
International Nuclear Information System (INIS)
Woods, T.
1991-02-01
The Hydrocarbon Supply Model is used to develop long-term trends in Lower-48 gas production and costs. The model utilizes historical find-rate patterns to predict the discovery rate and size distribution of future oil and gas field discoveries. The report documents the methodologies used to quantify historical oil and gas field find-rates and to project those discovery patterns for future drilling. It also explains the theoretical foundations for the find-rate approach. The new field and reserve growth resource base is documented and compared to other published estimates. The report has six sections. Section 1 provides background information and an overview of the model. Sections 2, 3, and 4 describe the theoretical foundations of the model, the databases, and specific techniques used. Section 5 presents the new field resource base by region and depth. Section 6 documents the reserve growth model components
ONODA, Tomoaki; YAMAMOTO, Ryuta; SAWAMURA, Kyohei; MURASE, Harutaka; NAMBO, Yasuo; INOUE, Yoshinobu; MATSUI, Akira; MIYAKE, Takeshi; HIRAI, Nobuhiro
2013-01-01
Percentile growth curves are often used as a clinical indicator to evaluate variations of children’s growth status. In this study, we propose empirical percentile growth curves using Z-scores adapted for Japanese Thoroughbred horses, with considerations of the seasonal compensatory growth that is a typical characteristic of seasonal breeding animals. We previously developed new growth curve equations for Japanese Thoroughbreds adjusting for compensatory growth. Individual horses and residual effects were included as random effects in the growth curve equation model and their variance components were estimated. Based on the Z-scores of the estimated variance components, empirical percentile growth curves were constructed. A total of 5,594 and 5,680 body weight and age measurements of male and female Thoroughbreds, respectively, and 3,770 withers height and age measurements were used in the analyses. The developed empirical percentile growth curves using Z-scores are computationally feasible and useful for monitoring individual growth parameters of body weight and withers height of young Thoroughbred horses, especially during compensatory growth periods. PMID:24834004
Role of nature reserves in giant panda protection.
Kang, Dongwei; Li, Junqing
2018-02-01
Giant panda (Ailuropoda melanoleuca) is a flagship species in nature conservation of the world; to protect this species, 67 nature reserves have been established in China. To evaluate the protection effect of giant panda nature reserves, we analyzed the variation of giant panda number and habitat area of 23 giant panda nature reserves of Sichuan province based on the national survey data released by State Forestry Administration and Sichuan Forestry Department. Results showed that from the third national survey to the fourth, giant panda number and habitat area of 23 giant panda nature reserves of Sichuan province failed to realize the significant increase. Furthermore, we found that the total population growth rate of 23 nature reserves in the last 12 years was lower than those of the province total of Sichuan and the national total of China, and the total habitat area of the 23 nature reserves was decreasing in the last 12 years, but the province total and national total were all increasing. We propose that giant panda protection should pay more attention to how to improve the protective effects of nature reserves.
Growth assessment in diagnosis of Fetal Growth Restriction. Review.
Albu, A R; Horhoianu, I A; Dumitrascu, M C; Horhoianu, V
2014-06-15
The assessment of fetal growth represents a fundamental step towards the identification of the true growth restricted fetus that is associated to important perinatal morbidity and mortality. The possible ways of detecting abnormal fetal growth are taken into consideration in this review and their strong and weak points are discussed. An important debate still remains about how to discriminate between the physiologically small fetus that does not require special surveillance and the truly growth restricted fetus who is predisposed to perinatal complications, even if its parameters are above the cut-off limits established. In this article, we present the clinical tools of fetal growth assessment: Symphyseal-Fundal Height (SFH) measurement, the fetal ultrasound parameters widely taken into consideration when discussing fetal growth: Abdominal Circumference (AC) and Estimated Fetal Weight (EFW); several types of growth charts and their characteristics: populational growth charts, standard growth charts, individualized growth charts, customized growth charts and growth trajectories.
Validation of a predictive model for the growth of chalk yeasts on bread.
Burgain, Anaïs; Bensoussan, Maurice; Dantigny, Philippe
2015-07-02
The present study focused on the effects of temperature, T, and water activity, aw, on the growth of Hyphopichia burtonii, Pichia anomala, and Saccharomycopsis fibuligera on Sabouraud Agar Medium. Cardinal values were estimated by means of cardinal models with inflection. All the yeasts were xerophilic, and they exhibited growth at 0.85 aw. The combined effects of T, aw, and pH on the growth of these species were described by the gamma-concept and validated on bread in the range of 15-25 °C, 0.91-0.97 aw, and pH 4.6-6.8. The optimum growth rates on bread were 2.88, 0.259, and 1.06 mm/day for H. burtonii, P. anomala, and S. fibuligera, respectively. The optimal growth rate of S. fibuligera on bread was about 2 fold that obtained on Sabouraud. Due to reproduction by budding, P. anomala exhibited low growth on Sabouraud and bread. However, this species is of major concern in the baker's industry because of the production of ethyl acetate in bread. Copyright © 2015 Elsevier B.V. All rights reserved.
All rights reserved and www.bioline.org.br/ja Estimation of exit ...
African Journals Online (AJOL)
ADOWIE PERE
and www.bioline.org.br/ja. Estimation of exit temperatures in the isentropic compression of real gases. 1 ..... other thermodynamic properties can be calculated within the framework of ... of negative compressibility) has no physical significance.
Mozumder, Md Salatul Islam; Garcia-Gonzalez, Linsey; De Wever, Heleen; Volcke, Eveline I P
2015-09-01
This study evaluates the effect of sodium (Na(+)) concentration on the growth and PHB production by Cupriavidus necator. Both biomass growth and PHB production were inhibited by Na(+): biomass growth became zero at 8.9 g/L Na(+) concentration while PHB production was completely stopped at 10.5 g/L Na(+). A mathematical model for pure culture heterotrophic PHB production was set up to describe the Na(+) inhibition effect. The parameters related to Na(+) inhibition were estimated based on shake flask experiments. The accumulated Na(+) showed non-linear inhibition effect on biomass growth but linear inhibition effect on PHB production kinetics. Fed-batch experiments revealed that a high accumulation of Na(+) due to a prolonged growth phase, using NaOH for pH control, decreased the subsequent PHB production. The model was validated based on independent experimental data sets, showing a good agreement between experimental data and simulation results. Copyright © 2015 Elsevier Ltd. All rights reserved.
Anthropogenic disturbances jeopardize biodiversity conservation within tropical rainforest reserves.
Martínez-Ramos, Miguel; Ortiz-Rodríguez, Iván A; Piñero, Daniel; Dirzo, Rodolfo; Sarukhán, José
2016-05-10
Anthropogenic disturbances affecting tropical forest reserves have been documented, but their ecological long-term cumulative effects are poorly understood. Habitat fragmentation and defaunation are two major anthropogenic threats to the integrity of tropical reserves. Based on a long-term (four decades) study, we document how these disturbances synergistically disrupt ecological processes and imperil biodiversity conservation and ecosystem functioning at Los Tuxtlas, the northernmost tropical rainforest reserve in the Americas. Deforestation around this reserve has reduced the reserve to a medium-sized fragment (640 ha), leading to an increased frequency of canopy-gap formation. In addition, hunting and habitat loss have caused the decline or local extinction of medium and large herbivores. Combining empirical, experimental, and modeling approaches, we support the hypothesis that such disturbances produced a demographic explosion of the long-lived (≈120 y old, maximum height of 7 m) understory palm Astrocaryum mexicanum, whose population has increased from 1,243-4,058 adult individuals per hectare in only 39 y (annual growth rate of ca 3%). Faster gap formation increased understory light availability, enhancing seed production and the growth of immature palms, whereas release from mammalian herbivory and trampling increased survival of seedlings and juveniles. In turn, the palm's demographic explosion was followed by a reduction of tree species diversity, changing forest composition, altering the relative contribution of trees to forest biomass, and disrupting litterfall dynamics. We highlight how indirect anthropogenic disturbances (e.g., palm proliferation) on otherwise protected areas threaten tropical conservation, a phenomenon that is currently eroding the planet's richest repositories of biodiversity.
Estimated impact of global population growth on future wilderness extent
Dumont, E.
2012-06-01
Wilderness areas in the world are threatened by the environmental impacts of the growing global human population. This study estimates the impact of birth rate on the future surface area of biodiverse wilderness and on the proportion of this area without major extinctions. The following four drivers are considered: human population growth (1), agricultural efficiency (2), groundwater drawdown by irrigation (3), and non-agricultural space used by humans (buildings, gardens, roads, etc.) (4). This study indicates that the surface area of biodiverse unmanaged land will reduce with about 5.4% between 2012 and 2050. Further, it indicates that the biodiverse land without major extinctions will reduce with about 10.5%. These percentages are based on a commonly used population trajectory which assumes that birth rates across the globe will reduce in a similar way as has occurred in the past in many developed countries. Future birth rate is however very uncertain. Plausible future birth rates lower than the expected rates lead to much smaller reductions in surface area of biodiverse unmanaged land (0.7% as opposed to 5.4%), and a reduction in the biodiverse land without major extinctions of about 5.6% (as opposed to 10.5%). This indicates that birth rate is an important factor influencing the quality and quantity of wilderness remaining in the future.
Effect of Estimated Daily Global Solar Radiation Data on the Results of Crop Growth Models
Directory of Open Access Journals (Sweden)
Herbert Formayer
2007-10-01
Full Text Available The results of previous studies have suggested that estimated daily globalradiation (RG values contain an error that could compromise the precision of subsequentcrop model applications. The following study presents a detailed site and spatial analysis ofthe RG error propagation in CERES and WOFOST crop growth models in Central Europeanclimate conditions. The research was conducted i at the eight individual sites in Austria andthe Czech Republic where measured daily RG values were available as a reference, withseven methods for RG estimation being tested, and ii for the agricultural areas of the CzechRepublic using daily data from 52 weather stations, with five RG estimation methods. In thelatter case the RG values estimated from the hours of sunshine using the ångström-Prescottformula were used as the standard method because of the lack of measured RG data. At thesite level we found that even the use of methods based on hours of sunshine, which showedthe lowest bias in RG estimates, led to a significant distortion of the key crop model outputs.When the ångström-Prescott method was used to estimate RG, for example, deviationsgreater than ±10 per cent in winter wheat and spring barley yields were noted in 5 to 6 percent of cases. The precision of the yield estimates and other crop model outputs was lowerwhen RG estimates based on the diurnal temperature range and cloud cover were used (mean bias error 2.0 to 4.1 per cent. The methods for estimating RG from the diurnal temperature range produced a wheat yield bias of more than 25 per cent in 12 to 16 per cent of the seasons. Such uncertainty in the crop model outputs makes the reliability of any seasonal yield forecasts or climate change impact assessments questionable if they are based on this type of data. The spatial assessment of the RG data uncertainty propagation over the winter wheat yields also revealed significant differences within the study area. We
Estimation of individual growth trajectories when repeated measures are missing
DEFF Research Database (Denmark)
Brooks, Mollie Elizabeth; Clements, Christopher; Pemberton, Josephine
2017-01-01
Individuals in a population vary in their growth due to hidden and observed factors such as age, genetics, environment, disease, and carryover effects from past environments. Because size affects fitness, growth trajectories scale up to affect population dynamics. However, it can be difficult to ...
Estimating light-vehicle sales in Turkey
Directory of Open Access Journals (Sweden)
Ufuk Demiroğlu
2016-09-01
Full Text Available This paper is motivated by the surprising rapid growth of new light-vehicle sales in Turkey in 2015. Domestic sales grew 25%, dramatically surpassing the industry estimates of around 8%. Our approach is to inform the sales trend estimate with the information obtained from the light-vehicle stock (the number of cars and light trucks officially registered in the country, and the scrappage data. More specifically, we improve the sales trend estimate by estimating the trend of its stock. Using household data, we show that an important reason for the rapid sales growth is that an increasing share of household budgets is spent on automobile purchases. The elasticity of light-vehicle sales to cyclical changes in aggregate demand is high and robust; its estimates are around 6 with a standard deviation of about 0.5. The price elasticity of light-vehicle sales is estimated to be about 0.8, but the estimates are imprecise and not robust. We estimate the trend level of light-vehicle sales to be roughly 7 percent of the existing stock. A remarkable out-of-sample forecast performance is obtained for horizons up to nearly a decade by a regression equation using only a cyclical gap measure, the time trend and obvious policy dummies. Various specifications suggest that the strong 2015 growth of light-vehicle sales was predictable in late 2014.
Anthun, Kjartan Sarheim; Kittelsen, Sverre Andreas Campbell; Magnussen, Jon
2017-04-01
This paper analyses productivity growth in the Norwegian hospital sector over a period of 16 years, 1999-2014. This period was characterized by a large ownership reform with subsequent hospital reorganizations and mergers. We describe how technological change, technical productivity, scale efficiency and the estimated optimal size of hospitals have evolved during this period. Hospital admissions were grouped into diagnosis-related groups using a fixed-grouper logic. Four composite outputs were defined and inputs were measured as operating costs. Productivity and efficiency were estimated with bootstrapped data envelopment analyses. Mean productivity increased by 24.6% points from 1999 to 2014, an average annual change of 1.5%. There was a substantial growth in productivity and hospital size following the ownership reform. After the reform (2003-2014), average annual growth was case mix between hospitals, and thus provides a framework for future studies. The study adds to the discussion on optimal hospital size. Copyright © 2017 Elsevier B.V. All rights reserved.
The development of an ore reserve methodology for the Olympic Dam copper-uranium-gold deposit
International Nuclear Information System (INIS)
Scott, I.R.
1987-01-01
At the Olympic Dam copper-uranium-gold deposit in South Australia, evolution in the understanding of the controls on mineralisation coupled with the changing demands of the project have led to changes in the approach to reserve estimation. The project has moved into a phase where detailed stope mining reserves are now required as distinct from global ore reserves. To enable the selective manipulation of geological and assay information and its characterisation, a relational database has been developed. For reserve calculations themselves, initial computations were based on a system derived from that used for the Kambalda nickel orebodies. The Olympic Dam system differed mainly in the use of statistical analyses in the estimation of grade instead of the previous polygonal area of influence weighting method. Three dimensional weighting techniques are now being used for local reserve estimates
Estimating the effect of urease inhibitor on rice yield based on NDVI at key growth stages
Directory of Open Access Journals (Sweden)
Kailou LIU,Yazhen LI,Huiwen HU
2014-06-01
Full Text Available The effect of the urease inhibitor, N-(n-butyl thiophosphoric triamide (NBPT at a range of application rates on rice production was examined in a field experiment at Jinxian County, Jiangxi Province, China. The normalized difference vegetation index (NDVI was measured at key growth stages in both early and late rice. The results showed that the grain yield increased significantly when urea was applied with NBPT, with the highest yield observed at 1.00% NBPT (wt/wt. NDVI differed with the growth stage of rice; it remained steady from the heading to the filling stage. Rice yield could be predicted from the NDVI taken at key rice growing stages, with R2 ranging from 0.34 to 0.69 in early rice and 0.49 to 0.70 in late rice. The validation test showed that RMSE (t·hm-2 values were 0.77 and 0.87 in early and late rice, respectively. Therefore, it was feasible to estimate rice yield for different amounts of urease inhibitor using NDVI.
Estimated harvesting on jellyfish in Sarawak
Bujang, Noriham; Hassan, Aimi Nuraida Ali
2017-04-01
There are three species of jellyfish recorded in Sarawak which are the Lobonema smithii (white jellyfish), Rhopilema esculenta (red jellyfish) and Mastigias papua. This study focused on two particular species which are L.smithii and R.esculenta. This study was done to estimate the highest carrying capacity and the population growth rate of both species by using logistic growth model. The maximum sustainable yield for the harvesting of this species was also determined. The unknown parameters in the logistic model were estimated using center finite different method. As for the results, it was found that the carrying capacity for L.smithii and R.esculenta were 4594.9246456819 tons and 5855.9894242086 tons respectively. Whereas, the population growth rate for both L.smithii and R.esculenta were estimated at 2.1800463754 and 1.144864086 respectively. Hence, the estimated maximum sustainable yield for harvesting for L.smithii and R.esculenta were 2504.2872047638 tons and 1676.0779949431 tons per year.
Thailand's energy security: Strategic Petroleum Reserve and its economic impacts
Leesombatpiboon, Poonpat
This dissertation studies Thailand's energy security from three related perspectives, the role of oil on the Thai macroeconomy, the sectoral demand for oil in Thailand, and the Strategic Petroleum Reserve (SPR) policy for the Thai economy. The first part of my dissertation estimates an error correction model of aggregate production function for Thailand. Thai economic growth is modeled as a function of labor, capital, and oil consumption. Unlike previous studies that focus on testing the causal relationship between energy consumption and economic growth, I focus on measuring the elasticity of economic growth with respect to oil consumption and oil prices. I find a cointegration relationship between GDP, capital, labor, and oil consumption. The results suggest that there exists a constant-return-to-scale characteristic in Thailand's aggregate production function with the contribution of labor, oil, and capital to output around 68, 19, and 13 percent respectively. The long-run and short-run contribution of oil consumption to the economy appears to be fairly close, suggesting that oil has a critical role in the Thai economy. In the short run, oil shortages have a much more severe impact on Thai economy than the effects of an oil price shock. For example, a 10 percent shortfall in oil consumption might cause economic growth to shrink by 2 percent within the same year while a sharp10 percent rise in oil prices canlead output growth to a fall by about 0.5 percent. The response of output to increases and decreases in oil prices is found to be asymmetric in the short run. The second part of my dissertation examines the short-run and long-run determinants of final oil consumption in seven major economic sectors in Thailand. Two different approaches are compared. The first approach uses dynamic panel data estimation techniques taking into account oil consumption of the whole economy in an aggregate manner. The second approach employs the Autoregressive Distributed Lag (ADL
Sea growth of anadromous brown trout (Salmo trutta)
Leeuw, de J.J.; Hofstede, ter R.; Winter, H.V.
2007-01-01
Sea growth rates were studied in anadromous brown trout caught in Lake IJsselmeer, The Netherlands. Growth in the first year at sea was estimated at 26 cm from length-frequency distributions, and at 21 cm from back-calculated growth rates from scale readings. These estimates are considerably higher
Uranium reserves and exploration activity
International Nuclear Information System (INIS)
Meehan, R.J.
1975-01-01
The strategy that ERDA plans to employ regarding resource appraisal is outlined. All types of uranium occurrences will be evaluated as sources of domestic ore reserves. Industry's exploration efforts will be compiled. These data will include information on land acquisition and costs, footage drilled and costs, estimates of exploration activities and expenditures, exploration for non-sandstone deposits, exploration in non-established areas, and foreign exploration plans and costs. Typical data in each of these areas are given
Postnatal growth, age estimation and development of foraging ...
Indian Academy of Sciences (India)
Unknown
mothers. There was no significant difference in the growth pattern of the young maintained in captivity compared ..... interactions, and development of vocalizations in the vesper- ... Kunz T H and Hood W R 2000 Parental care and postnatal.
Thangavel, Kalaiselvi; Radha Krishnan, Preethi; Nagaiah, Srimeena; Kuppusamy, Senthil; Chinnasamy, Senthil; Rajadorai, Jude Sudhagar; Nellaiappan Olaganathan, Gopal; Dananjeyan, Balachandar
2018-01-03
Renewable energy for sustainable development is a subject of a worldwide debate since continuous utilization of non-renewable energy sources has a drastic impact on the environment and economy; a search for alternative energy resources is indispensable. Microalgae are promising and potential alternate energy resources for biodiesel production. Thus, our efforts were focused on surveying the natural diversity of microalgae for the production of biodiesel. The present study aimed at identification, isolation, and characterization of oleaginous microalgae from shola forests of Nilgiri Biosphere Reserve (NBR), the biodiversity hot spot of India, where the microalgal diversity has not yet been systematically investigated. Overall the higher biomass yield, higher lipid accumulation and thermotolerance observed in the isolated microalgal strains have been found to be the desirable traits for the efficient biodiesel production. Species composition and diversity analysis yielded ten potential microalgal isolates belonging to Chlorophyceae and Cyanophyceae classes. The chlorophytes exhibited higher growth rate, maximum biomass yield, and higher lipid accumulation than Cyanophyceae. Among the chlorophytes, the best performing strains were identified and represented by Acutodesmus dissociatus (TGA1), Chlorella sp. (TGA2), Chlamydomonadales sp. (TGA3) and Hindakia tetrachotoma (PGA1). The Chlamydomonadales sp. recorded with the highest growth rate, lipid accumulation and biomass yield of 0.28 ± 0.03 day -1 (μ exp ), 29.7 ± 0.69% and 134.17 ± 16.87 mg L -1 day -1 , respectively. It was also found to grow well at various temperatures, viz., 25 °C, 35 °C, and 45 °C, indicating its suitability for open pond cultivation. The fatty acid methyl ester (FAME) analysis of stationary phase cultures of selected four algal strains by tandem mass spectrograph showed C16:0, C18:1 and C18:3 as dominant fatty acids suitable for biodiesel production. All the three
The influence of IVF/ICSI treatment on human embryonic growth trajectories.
Eindhoven, S C; van Uitert, E M; Laven, J S E; Willemsen, S P; Koning, A H J; Eilers, P H C; Exalto, N; Steegers, E A P; Steegers-Theunissen, R P M
2014-12-01
groups (βIVF/ICSI = 6 g; P = 0.36 and βIVF/ICSI = 80 g; P = 0.24, respectively). Variations in embryonic growth trajectories of spontaneously conceived pregnancies with reliable pregnancy dating may partially be a result of less precise pregnancy dating and differences in endometrium receptivity compared with IVF/ICSI pregnancies. The absence of a significant difference in embryonic and fetal growth trajectories suggests safety of IVF/ICSI treatment with regard to early embryonic growth. However, further research is warranted to ascertain the influence of IVF/ICSI treatments in a larger study population, and to estimate the impact of the underlying causes of the subfertility and other periconceptional exposures on human embryonic and fetal growth trajectories. This study was supported by the Department of Obstetrics and Gynaecology of the Erasmus MC, University Medical Centre. No competing interests are declared. © The Author 2014. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved. For Permissions, please email: journals.permissions@oup.com.
International Nuclear Information System (INIS)
Kotoku, Shinya; Matsuzaki, Masunori; Otani, Nozomi
1988-01-01
To assess the accuracy of digital subtraction angiography in evaluating coronary flow reserve in cases with critical coronary artery stenosis, time-density curves were obtained from digital subtraction coronary angiograms in the myocardial region of interest. Time to peak contrast (TPC) and time constant of the washout exponential curve (T) were measured in 14 patients with stable effort angina pectoris and critical one vessel lesion before and after percutaneous transluminal coronary angioplasty (PTCA). All patients had normal left ventricular ejection fraction (59±7%) and 201 Tl myocardial images at rest. The values of TPC and T were significantly shortened from 5.4±1.3 to 4.5±1.0 sec (p<0.02) and from 10.9±3.8 to 5.3±1.3 sec (p<0.001) after PTCA, respectively. However, in 9 patients TPC values were approximately the same before and after PTCA. In five experimental dogs with critical circumflex coronary artery stenosis, coronary flow (CF; Doppler flowmeter) and systolic thickening of the posterior wall (by sonomicrometry) at rest did not differ from those of the controls. However, contrast media-induced reactive hyperemia was markedly attenuated, accompanied by a significant increase in T (7.7±4.5 vs 15.8±10.9 sec, p<0.01) and totally unchanged TPC (both 6.8 sec). With simultaneous tracings of CF and time-density curves, TPC and washout phases corresponded with contrast-induced transient CF reduction and hyperemic phases, respectively. We concluded that T may be more sensitive for estimating CF maintained nearly normal, e.g., in patients with stable effort angina pectoris having normal left ventricular wall motion at rest. (author)
GaN growth via HVPE on SiC/Si substrates: growth mechanisms
Sharofidinov, Sh Sh; Redkov, A. V.; Osipov, A. V.; Kukushkin, S. A.
2017-11-01
The article focuses on the study of GaN thin film growth via chloride epitaxy on SiC/Si hybrid substrate. SiC buffer layer was grown by a method of substitution of atoms, which allows one to reduce impact of mechanical stress therein on subsequent growth of III-nitride films. It is shown, that change in GaN growth conditions leads to change in its growth mechanism. Three mechanisms: epitaxial, spiral and stepwise growth are considered and mechanical stresses are estimated via Raman spectroscopy.
Wind offering in energy and reserve markets
DEFF Research Database (Denmark)
Soares, Tiago; Pinson, Pierre; Morais, Hugo
2016-01-01
The increasing penetration of wind generation in power systems to fulfil the ambitious European targets will make wind power producers to play an even more important role in the future power system. Wind power producers are being incentivized to participate in reserve markets to increase...... their revenue, since currently wind turbine/farm technologies allow them to provide ancillary services. Thus, wind power producers are to develop offering strategies for participation in both energy and reserve markets, accounting for market rules, while ensuring optimal revenue. We consider a proportional...... offering strategy to optimally decide upon participation in both markets by maximizing expected revenue from day-ahead decisions while accounting for estimated regulation costs for failing to provide the services. An evaluation of considering the same proportional splitting of energy and reserve in both...
Legaspi, Benjamin C; Legaspi, Jesusa Crisostomo
2010-04-01
Invasive pests, such as the cactus moth, Cactoblastis cactorum (Berg) (Lepidoptera: Pyralidae), have not reached equilibrium distributions and present unique opportunities to validate models by comparing predicted distributions with eventual realized geographic ranges. A CLIMEX model was developed for C. cactorum. Model validation was attempted at the global scale by comparing worldwide distribution against known occurrence records and at the field scale by comparing CLIMEX "growth indices" against field measurements of larval growth. Globally, CLIMEX predicted limited potential distribution in North America (from the Caribbean Islands to Florida, Texas, and Mexico), Africa (South Africa and parts of the eastern coast), southern India, parts of Southeast Asia, and the northeastern coast of Australia. Actual records indicate the moth has been found in the Caribbean (Antigua, Barbuda, Montserrat Saint Kitts and Nevis, Cayman Islands, and U.S. Virgin Islands), Cuba, Bahamas, Puerto Rico, southern Africa, Kenya, Mexico, and Australia. However, the model did not predict that distribution would extend from India to the west into Pakistan. In the United States, comparison of the predicted and actual distribution patterns suggests that the moth may be close to its predicted northern range along the Atlantic coast. Parts of Texas and most of Mexico may be vulnerable to geographic range expansion of C. cactorum. Larval growth rates in the field were estimated by measuring differences in head capsules and body lengths of larval cohorts at weekly intervals. Growth indices plotted against measures of larval growth rates compared poorly when CLIMEX was run using the default historical weather data. CLIMEX predicted a single period conducive to insect development, in contrast to the three generations observed in the field. Only time and more complete records will tell whether C. cactorum will extend its geographical distribution to regions predicted by the CLIMEX model. In terms
Villar, José; Cheikh Ismail, Leila; Staines Urias, Eleonora; Giuliani, Francesca; Ohuma, Eric O; Victora, Cesar G; Papageorghiou, Aris T; Altman, Douglas G; Garza, Cutberto; Barros, Fernando C; Puglia, Fabien; Ochieng, Roseline; Jaffer, Yasmin A; Noble, Julia A; Bertino, Enrico; Purwar, Manorama; Pang, Ruyan; Lambert, Ann; Chumlea, Cameron; Stein, Alan; Fernandes, Michelle; Bhutta, Zulfiqar A; Kennedy, Stephen H
2018-02-01
used to estimate the percentage variability among individuals within a study site compared with that among study sites. There were 3711 eligible singleton live births; 3042 children (82%) were evaluated at 2 years of age. There were no substantive differences between the included group and the lost-to-follow up group. Infant mortality rate was 3 per 1000; neonatal mortality rate was 1.6 per 1000. At the 2-year visit, the children included in the INTERGROWTH-21 st Fetal Growth Standards were at the 49th percentile for length, 50th percentile for head circumference, and 58th percentile for weight of the World Health Organization Child Growth Standards. Similar results were seen for the preterm subgroup that was included in the INTERGROWTH-21 st Preterm Postnatal Growth Standards. The cohort overlapped between the 3rd and 97th percentiles of the World Health Organization motor development milestones. We estimated that the variance among study sites explains only 5.5% of the total variability in the length of the children between birth and 2 years of age, although the variance among individuals within a study site explains 42.9% (ie, 8 times the amount explained by the variation among sites). An increase of 8.9 cm in adult height over mean parental height is estimated to occur in the cohort from low-middle income countries, provided that children continue to have adequate health, environmental, and nutritional conditions. The cohort enrolled in the INTERGROWTH-21 st standards remained healthy with adequate growth and motor development up to 2 years of age, which supports its appropriateness for the construction of international fetal and preterm postnatal growth standards. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.
Energy Technology Data Exchange (ETDEWEB)
Nakamura, Toshio, E-mail: nakamura@nendai.nagoya-u.ac.jp [Center for Chronological Research, Nagoya University, Chikusa, Nagoya, Aichi 464-8602 (Japan); Koike, Hiroko [Kyushu University Museum, Kyushu University, Hakozaki, Fukuoka, Fukuoka 814-0180 (Japan); Aizawa, Jun; Okuno, Mitsuru [Department of Earth System Science, Faculty of Science, Fukuoka University, 8-19-1 Nanakuma, Jonan-ku, Fukuoka, Fukuoka 814-0180 (Japan)
2015-10-15
In this study, {sup 14}C analysis by accelerator mass spectrometry (AMS) was applied to age estimation based on temporal variations in bomb-produced-{sup 14}C contents of a full elephant tusk registered at Kyushu University. The tusk measured 175 cm long and 13.8 cm in diameter at the root. Thirty tusk-fragment samples were used for {sup 14}C analysis with AMS to estimate the formation ages of different positions according to catalogued global {sup 14}C contents (F{sup 14}C). The F{sup 14}C value of the tip of the tusk suggested that the elephant was born around 1980, while that of the root suggested death around 1994, a lifespan of at least 14 years, rather shorter period than the average lifetime of an elephant (ca. 80 years). In addition, the F{sup 14}C values of fragments collected along a cross-sectional line suggested that the outer part of the tusk formed first with inner parts being deposited gradually with growth.
International Nuclear Information System (INIS)
Nakamura, Toshio; Koike, Hiroko; Aizawa, Jun; Okuno, Mitsuru
2015-01-01
In this study, "1"4C analysis by accelerator mass spectrometry (AMS) was applied to age estimation based on temporal variations in bomb-produced-"1"4C contents of a full elephant tusk registered at Kyushu University. The tusk measured 175 cm long and 13.8 cm in diameter at the root. Thirty tusk-fragment samples were used for "1"4C analysis with AMS to estimate the formation ages of different positions according to catalogued global "1"4C contents (F"1"4C). The F"1"4C value of the tip of the tusk suggested that the elephant was born around 1980, while that of the root suggested death around 1994, a lifespan of at least 14 years, rather shorter period than the average lifetime of an elephant (ca. 80 years). In addition, the F"1"4C values of fragments collected along a cross-sectional line suggested that the outer part of the tusk formed first with inner parts being deposited gradually with growth.
U.S. crude oil, natural gas, and natural gas liquids reserves 1997 annual report
Energy Technology Data Exchange (ETDEWEB)
Wood, John H.; Grape, Steven G.; Green, Rhonda S.
1998-12-01
This report presents estimates of proved reserves of crude oil, natural gas, and natural gas liquids as of December 31, 1997, as well as production volumes for the US and selected States and State subdivisions for the year 1997. Estimates are presented for the following four categories of natural gas: total gas (wet after lease separation), nonassociated gas and associated-dissolved gas (which are the two major types of wet natural gas), and total dry gas (wet gas adjusted for the removal of liquids at natural gas processing plants). In addition, reserve estimates for two types of natural gas liquids, lease condensate and natural gas plant liquids, are presented. Also included is information on indicated additional crude oil reserves and crude oil, natural gas, and lease condensate reserves in nonproducing reservoirs. A discussion of notable oil and gas exploration and development activities during 1997 is provided. 21 figs., 16 tabs.
Short communication Estimation of growth curve parameters in ...
African Journals Online (AJOL)
ikeskin
The shape of growth curves has been reported to vary according to the species of .... a,b,c The means within columns with different superscripts are significantly .... J. Anim. Sci. 84, 2642-2654. The South African Journal of Animal Science is ...
Sensorless Reserved Power Control Strategy for Two-Stage Grid-Connected Photovoltaic Systems
DEFF Research Database (Denmark)
Sangwongwanich, Ariya; Yang, Yongheng; Blaabjerg, Frede
2016-01-01
Due to still increasing penetration level of grid-connected Photovoltaic (PV) systems, advanced active power control functionalities have been introduced in grid regulations. A reserved power control, where the active power from the PV panels is reserved during operation, is required for grid...... support. In this paper, a cost-effective solution to realize the reserved power control for grid-connected PV systems is proposed. The proposed solution routinely employs a Maximum Power Point Tracking (MPPT) control to estimate the available PV power and a Constant Power Generation (CPG) control...... to achieve the power reserve. In this method, the irradiance measurements that have been used in conventional control schemes to estimate the available PV power are not required, and thereby being a sensorless solution. Simulations and experimental tests have been performed on a 3-kW two-stage single...
Are Private Reserves Effective for Jaguar Conservation?
Directory of Open Access Journals (Sweden)
Carmina E Gutiérrez-González
Full Text Available We present the first study of density and apparent survival for a jaguar (Panthera onca population in northern Mexico using 13 years of camera trap data from 2000 to 2012. We used the Barker robust design model which combines data from closed sampling periods and resight data between these periods to estimate apparent survival and abundance. We identified 467 jaguar pictures that corresponded to 48 jaguar individuals. We included camera type and field technician as covariates for detection probabilities. We used three covariates to evaluate the effect of reserve on jaguar apparent survival: i private reserve creation ii later reserve expansions, and iii cattle ranches' conservation activities. We found that the use of digital cameras in addition to film cameras increased detection probability by a factor of 6x compared with the use of only film cameras (p = 0.34 ± 0.05 and p = 0.05 ± 0.02 respectively in the closed period and more than three times in the open period (R = 0.91 ± 0.08 and R = 0.30 ± 0.13 mixed and film cameras respectively. Our availability estimates showed no temporary emigration and a fidelity probability of 1. Despite an increase of apparent survival probability from 0.47 ± 0.15 to 0.56 ± 0.11 after 2007, no single covariate explained the change in these point estimates. Mean jaguar density was 1.87 ± 0.47 jaguars/100 km2. We found that 13 years of jaguar population monitoring with our sampling size were not enough for detecting changes in survival or density. Our results provide a baseline for studies evaluating the effectiveness of protected areas and the inclusion of ranch owners in jaguar conservation programs and long-term population viability.
Estimating the Threshold Level of Inflation for Thailand
Jiranyakul, Komain
2017-01-01
Abstract. This paper analyzes the relationship between inflation and economic growth in Thailand using annual dataset during 1990 and 2015. The threshold model is estimated for different levels of threshold inflation rate. The results suggest that the threshold level of inflation above which inflation significantly slow growth is estimated at 3 percent. The negative relationship between inflation and growth is apparent above this threshold level of inflation. In other words, the inflation rat...
Factors Affecting Tufa Degradation in Jiuzhaigou National Nature Reserve, Sichuan, China
Directory of Open Access Journals (Sweden)
Lixia Liu
2017-09-01
Full Text Available Water and tufa samples were collected from Arrow Bamboo Lake, the stream from Panda Lake to Five-Color Lake, Pearl Shoal and Shuzheng Lakes in Jiuzhaigou National Nature Reserve, China, between October 2013 and September 2014, to investigate tufa growth rate and water environment (water temperature, pH, electric conductivity, major ions and nutrients, and analyzed to explore the main causes of tufa degradation. The mean annual rate of tufa growth was low and varied within lakes, with the maximum deposit thickness of 332 μm/y. The calcite saturation index ranged from 0.65 to 0.83. Scanning electron microscope images showed that the tufa deposits had non-isopachous structures, and diatoms were the dominant microorganisms that participated in tufa deposition. Porous and crystalline structures of deposits were linked with a high tufa growth and small amounts of diatoms. Conversely, tufa deposits with amorphous and loose structures showed a low crystal growth rate and a high number of diatoms. A one-way analysis of variance and a least significant difference test were applied to identify site differences in water chemistry. Linear correlations indicated that nitrate, phosphate and sulfate inhibit tufa growth (p < 0.05. Increased nitrogen and phosphorus concentrations that originate mainly from atmospheric pollution and tourist activities at scenic attractions could trigger excessive diatom growth, which inhibits tufa precipitation. A series of measures should be implemented (e.g., the visitor number and vehicles should be regulated and controlled to minimize tufa degradation in the Jiuzhaigou National Nature Reserve.
Rural Sprawl and the Impact of Human Land Use on the Pine Ridge Indian Reservation, South Dakota
Campbell, R.; Bennett, T.
2005-12-01
The most important impact on global land cover is human use and development. With the recent population growth occurring on the reservations in South Dakota, specifically Pine Ridge Indian Reservation, the towns and communities of the reservation are undergoing change. Although urban sprawl certainly is not a consideration on the reservations, the population explosion currently underway has seen a subsequent increase in rural sprawl. In this case, rural sprawl is defined as exponential population growth and geographic expansion of remote reservation communities. The capacity of satellite imagery to encompass large land tracts make the use of this technology a cost effective way to visualize and investigate population growth in rural communities. Likewise, integrating remotely sensed data into a Geographic Information Systems (GIS) can be a powerful tool to identify environmental and other land use issues that impact the people and communities in and around the Pine Ridge area. The objective of this research is to (1) observe and calculate land cover change around three communities on the Pine Ridge Indian reservation using remotely sensed data (Landsat MSS, TM and ETM+) and Geographic Information Systems over a 20 year span, and (2) to discuss the potential impacts of rural sprawl on the Pine Ridge Reservation, SD. Preliminary results indicate that land cover has changed in relationship to increased population growth within three communities on the reservation. New housing developments, roads and buildings have appeared and these changes were detectable using Landsat imagery. These results will be discussed along with the experiences and education through the NASA Goddard Internship sponsored by the North Dakota Association of Tribal Colleges.
Miyagawa, Masao; Nishiyama, Yoshiko; Uetani, Teruyoshi; Ogimoto, Akiyoshi; Ikeda, Shuntaro; Ishimura, Hayato; Watanabe, Emiri; Tashiro, Rami; Tanabe, Yuki; Kido, Teruhito; Kurata, Akira; Mochizuki, Teruhito
2017-10-01
Quantitative assessment of myocardial flow reserve (MFR) by single photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI) is challenging but may facilitate evaluation of multi-vessel coronary artery disease (CAD). We enrolled 153 patients with suspected or known CAD, referred for pharmacological stress MPI. They underwent a 99m Tc-perfusion stress/rest SPECT with an ultrafast cadmium-zinc-telluride (CZT) camera. Dynamic data were acquired and time-activity curves fitted to a 1-tissue compartment analysis with input function. K1 was assigned for stress and rest data. The MFR index (MFRi) was calculated as K1 stress/K1 at-rest. The findings were validated by invasive coronary angiography in 69 consecutive patients. The global MFRi was 1.46 (1.16-1.76), 1.33 (1.12-1.54), and 1.18 (1.01-1.35), for 1-vessel disease (VD), 2-VD, and 3-VD, respectively. In the 3-VD, global MFRi was lower than that in 0-VD (1.63 [1.22-2.04], Pfraction (OR: 61.6 [57.5-66.0]), and global MFRi (OR: 119.6 [111.5-127.7], P=0.002). A cut-off value of 1.3 yielded 93.3% sensitivity and 75.9% specificity for diagnosing 3-VD. Fractional flow reserve positively correlated with regional MFRi (r=0.62, P=0.008), and the SYNTAX score correlated negatively with global MFRi (r=0.567, P=0.0003). We developed and validated a clinically available method for MFR quantification by dynamic 99m Tc-perfusion SPECT utilizing a CZT camera, which improves the detectability of multi-vessel CAD. Copyright © 2017 Elsevier B.V. All rights reserved.
Dudley, Robert W.; Trial, Joan G.
2014-01-01
This report is the product of a 2013 cooperative agreement between the U.S. Geological Survey, the International Joint Commission, and the Maine Bureau of Sea Run Fisheries and Habitat to quantify the effects of meteorological conditions (from 1970 through 2008) on the survival of smallmouth bass (Micropterus dolomieu) in the first year of life in Spednic Lake. This report documents the data and methods used to estimate historical daily mean lake surface-water temperatures from early spring through late autumn, which were used to estimate the dates of smallmouth bass spawning, young-of-the-year growth, and probable strength of each year class. Mortality of eggs and fry in nests was modeled and estimated to exceed 10 percent in 17 of 39 years; during those years, cold temperatures in the early part of the spawning period resulted in mortality to fish that were estimated to have had the longest growing season and attain the greatest length. Modeled length-dependent overwinter survival combined with early mortality identified 1986, 1994, 1996, and 2004 as the years in which temperature was likely to have presented the greatest challenge to year-class strength in the Spednic Lake fishery. Age distribution of bass in fisheries on lakes in the St. Croix and surrounding watersheds confirmed that conditions in 1986 and 1996 resulted in weak smallmouth bass year classes (age-four or age-five bass representing less than 15 percent of a 100-fish sample).
Zvoch, Keith
2016-01-01
Piecewise growth models (PGMs) were used to estimate and model changes in the preliteracy skill development of kindergartners in a moderately sized school district in the Pacific Northwest. PGMs were applied to interrupted time-series (ITS) data that arose within the context of a response-to-intervention (RtI) instructional framework. During the…
Alberta's reserves 2004 and supply/demand outlook 2005-2014
International Nuclear Information System (INIS)
Burrowes, A.; Marsh, R.; Ramdin, N.; Evans, C.; Kirsch, M.A.; Philp, L.; Fujda, M.; Stenson, J.; Sadler, K.; Sankey, G.; Hill, C.; Rahnama, F.; Habib, G.; MacGillivray, J.
2005-01-01
This document presents information on the state of reserves, supply, and demand for Alberta's energy resources including bitumen, crude oil, coalbed methane (CBM), conventional natural gas, natural gas liquids, sulphur, and coal. Estimates of initial reserves, remaining established reserves, and ultimate potential were also included, along with a 10-year supply and demand forecast for Alberta's energy resources. The document presents major forecast assumptions that influence Alberta's energy supply and demand. Some of the main variables affecting energy supply and demand include the global oil market, energy prices, Canadian economic performance and the economic outlook for Alberta. The development of Alberta's energy resources depends on reserve supply, costs of development, energy demands, conservation, and social, economic and environmental considerations. In 2004, raw bitumen production continued to grow and accounted for 69 per cent of Alberta's total crude oil and bitumen production. The value-added process of upgrading raw bitumen to synthetic crude oil was also expanded in 2004. Natural gas production from all sources in Alberta increased by 1 per cent compared with 2003. CBM development also increased greatly in 2004. Although it accounted for 80 per cent of the cumulative CBM production to date, it only contributed 0.5 per cent of the provincial total natural gas production. It is expected that CBM development will continue to increase in the coming years. For that reason, a separate estimate of CBM reserves was included. tabs., figs
Lasarte-Velillas, J J; Hernández-Aguilar, M T; Martínez-Boyero, T; Soria-Cabeza, G; Soria-Ruiz, D; Bastarós-García, J C; Gil-Hernández, I; Pastor-Arilla, C; Lasarte-Sanz, I
2015-03-01
To investigate the prevalence of overweight and obesity among our pediatric population and observe whether the use of different growth references for classification produce significant differences. A total of 35824 boys and girls aged between 2 and 14 years were included. Body mass index (BMI) was used to calculate the prevalence of overweight-obesity by age and sex. Prevalence was obtained by using a set of national references (Hernández's standards) and the references of World Health Organization (WHO standards). Prevalences were compared for each age and sex subset, as well as with the percentage of patients who had an overweight-obesity diagnosis in the clinical record. The overall prevalence of overweight-obesity among children aged 2 to 14 years was 17.0% (95% CI; 16.1%-18.0%) according to the Hernández standards vs 30.8% (95% CI; 29.9%-31.7%) according to WHO standards (10.1% vs 12.2% obese, and 6.9% vs 18.6% overweight). It was significantly higher in boys, by both standards, due to the higher prevalence of obesity. By using the Hernández standards the prevalence was significantly lower than by using WHO standards for all ages and for both sexes. A low percentage of patients were found to have an obesity-overweight diagnosis in the clinical record (from 3% to 22% at the ages of 2 and 14 years, respectively). The prevalence of overweight-obesity in our population is high, especially among boys. Using Hernández standards leads to an under-estimation of the problem, especially because it detects less overweight patients, thus we recommend using the WHO standards in our daily practice. The low number of overweight-obesity diagnoses in the clinical records might reflect that there is little awareness of the problem by the professionals. Copyright © 2013 Asociación Española de Pediatría. Published by Elsevier España, S.L.U. All rights reserved.
MEASURING ECONOMIC GROWTH FROM OUTER SPACE
Henderson, J. Vernon; Storeygard, Adam; Weil, David N.
2013-01-01
GDP growth is often measured poorly for countries and rarely measured at all for cities or subnational regions. We propose a readily available proxy: satellite data on lights at night. We develop a statistical framework that uses lights growth to augment existing income growth measures, under the assumption that measurement error in using observed light as an indicator of income is uncorrelated with measurement error in national income accounts. For countries with good national income accounts data, information on growth of lights is of marginal value in estimating the true growth rate of income, while for countries with the worst national income accounts, the optimal estimate of true income growth is a composite with roughly equal weights. Among poor-data countries, our new estimate of average annual growth differs by as much as 3 percentage points from official data. Lights data also allow for measurement of income growth in sub- and supranational regions. As an application, we examine growth in Sub Saharan African regions over the last 17 years. We find that real incomes in non-coastal areas have grown faster by 1/3 of an annual percentage point than coastal areas; non-malarial areas have grown faster than malarial ones by 1/3 to 2/3 annual percent points; and primate city regions have grown no faster than hinterland areas. Such applications point toward a research program in which “empirical growth” need no longer be synonymous with “national income accounts.” PMID:25067841
Dietary arginine and linear growth
DEFF Research Database (Denmark)
van Vught, Anneke J A H; Dagnelie, Pieter C; Arts, Ilja C W
2013-01-01
Child Intervention Study during 2001-2 (baseline), and at 3-year and 7-year follow-up, were used. Arginine intake was estimated via a 7 d precoded food diary at baseline and 3-year follow-up. Data were analysed in a multilevel structure in which children were embedded within schools. Random intercept......The amino acid arginine is a well-known growth hormone (GH) stimulator and GH is an important modulator of linear growth. The aim of the present study was to investigate the effect of dietary arginine on growth velocity in children between 7 and 13 years of age. Data from the Copenhagen School...... and slopes were defined to estimate the association between arginine intake and growth velocity, including the following covariates: sex; age; baseline height; energy intake; puberty stage at 7-year follow-up and intervention/control group. The association between arginine intake and growth velocity...
International Nuclear Information System (INIS)
Sorini, D.
2017-01-01
Measuring the clustering of galaxies from surveys allows us to estimate the power spectrum of matter density fluctuations, thus constraining cosmological models. This requires careful modelling of observational effects to avoid misinterpretation of data. In particular, signals coming from different distances encode information from different epochs. This is known as ''light-cone effect'' and is going to have a higher impact as upcoming galaxy surveys probe larger redshift ranges. Generalising the method by Feldman, Kaiser and Peacock (1994) [1], I define a minimum-variance estimator of the linear power spectrum at a fixed time, properly taking into account the light-cone effect. An analytic expression for the estimator is provided, and that is consistent with the findings of previous works in the literature. I test the method within the context of the Halofit model, assuming Planck 2014 cosmological parameters [2]. I show that the estimator presented recovers the fiducial linear power spectrum at present time within 5% accuracy up to k ∼ 0.80 h Mpc −1 and within 10% up to k ∼ 0.94 h Mpc −1 , well into the non-linear regime of the growth of density perturbations. As such, the method could be useful in the analysis of the data from future large-scale surveys, like Euclid.
Re-assessing copepod growth using the Moult Rate method
DEFF Research Database (Denmark)
Hirst, Andrew G.; Keister, J. E.; Richardson, A. J.
2014-01-01
Estimating growth and production rates of mesozooplankton, and copepods in particular, is important in describing flows of material and energy though pelagic systems. Over the past 30 years, the Moult Rate (MR) method has been used to estimate juvenile copepod growth rates in ∼40 papers. Yet the MR......-moulting stage, e.g. copepodite stage 5 to adult. We performed experiments with Calanus pacificus to estimate growth of stage C5 using an alternative method. We found that the error size and sign varied between mass type (i.e. DW, C and N). Recommendations for practical future assessments of growth in copepods...
Tree-growth analyses to estimate tree species' drought tolerance.
Eilmann, Britta; Rigling, Andreas
2012-02-01
Climate change is challenging forestry management and practices. Among other things, tree species with the ability to cope with more extreme climate conditions have to be identified. However, while environmental factors may severely limit tree growth or even cause tree death, assessing a tree species' potential for surviving future aggravated environmental conditions is rather demanding. The aim of this study was to find a tree-ring-based method suitable for identifying very drought-tolerant species, particularly potential substitute species for Scots pine (Pinus sylvestris L.) in Valais. In this inner-Alpine valley, Scots pine used to be the dominating species for dry forests, but today it suffers from high drought-induced mortality. We investigate the growth response of two native tree species, Scots pine and European larch (Larix decidua Mill.), and two non-native species, black pine (Pinus nigra Arnold) and Douglas fir (Pseudotsuga menziesii Mirb. var. menziesii), to drought. This involved analysing how the radial increment of these species responded to increasing water shortage (abandonment of irrigation) and to increasingly frequent drought years. Black pine and Douglas fir are able to cope with drought better than Scots pine and larch, as they show relatively high radial growth even after irrigation has been stopped and a plastic growth response to drought years. European larch does not seem to be able to cope with these dry conditions as it lacks the ability to recover from drought years. The analysis of trees' short-term response to extreme climate events seems to be the most promising and suitable method for detecting how tolerant a tree species is towards drought. However, combining all the methods used in this study provides a complete picture of how water shortage could limit species.
Fundamental Drivers of the Cost and Price of Operating Reserves
Energy Technology Data Exchange (ETDEWEB)
Hummon, Marissa [National Renewable Energy Lab. (NREL), Golden, CO (United States); Denholm, Paul [National Renewable Energy Lab. (NREL), Golden, CO (United States); Jorgenson, Jennie [National Renewable Energy Lab. (NREL), Golden, CO (United States); Palchak, David [National Renewable Energy Lab. (NREL), Golden, CO (United States); Kirby, Brendan [Kirby Consultant; Ma, Ookie [U.S. Department of Energy, Washington, DC (United States)
2013-07-01
Operating reserves impose a cost on the electric power system by forcing system operators to keep partially loaded spinning generators available for responding to system contingencies variable demand. In many regions of the United States, thermal power plants provide a large fraction of the operating reserve requirement. Alternative sources of operating reserves, such as demand response and energy storage, may provide more efficient sources of these reserves. However, to estimate the potential value of these services, the cost of reserve services under various grid conditions must first be established. This analysis used a commercial grid simulation tool to evaluate the cost and price of several operating reserve services, including spinning contingency reserves and upward regulation reserves. These reserve products were evaluated in a utility system in the western United States, considering different system flexibilities, renewable energy penetration, and other sensitivities. The analysis demonstrates that the price of operating reserves depend highly on many assumptions regarding the operational flexibility of the generation fleet, including ramp rates and the fraction of fleet available to provide reserves.
Oil Reserves and Production in the Gulf with Special Reference to Qatar
International Nuclear Information System (INIS)
Ibrahim, Ismail.
1998-01-01
Oil and natural gas potential of the Gulf Arab Countries is substantial. The proven oil reserves of these countries constitute 55% of total world proven oil reserves. The Gulf Arab Countries possess 576 billion barrels of proven crude oil reserves, as compared to total world proven oil reserves of around 1047. Natural gas resources are also plentiful in the Gulf Arab Countries. Proven natural gas reserves were estimated at around 26 trillion cubic metres, at the beginning of 1997. This figure represents around 17% of total world proven natural gas reserves of around 153 trillion cubic metres
Wind offering in energy and reserve markets
Soares, T.; Pinson, P.; Morais, H.
2016-09-01
The increasing penetration of wind generation in power systems to fulfil the ambitious European targets will make wind power producers to play an even more important role in the future power system. Wind power producers are being incentivized to participate in reserve markets to increase their revenue, since currently wind turbine/farm technologies allow them to provide ancillary services. Thus, wind power producers are to develop offering strategies for participation in both energy and reserve markets, accounting for market rules, while ensuring optimal revenue. We consider a proportional offering strategy to optimally decide upon participation in both markets by maximizing expected revenue from day-ahead decisions while accounting for estimated regulation costs for failing to provide the services. An evaluation of considering the same proportional splitting of energy and reserve in both day- ahead and balancing market is performed. A set of numerical examples illustrate the behavior of such strategy. An important conclusion is that the optimal split of the available wind power between energy and reserve strongly depends upon prices and penalties on both market trading floors.
Manrique-Alba, Àngela; Ruiz-Yanetti, Samantha; Moutahir, Hassane; Novak, Klemen; De Luis, Martin; Bellot, Juan
2017-01-01
In Mediterranean areas with limited availability of water, an accurate knowledge of growth response to hydrological variables could contribute to improving management and stability of forest resources. The main goal of this study is to assess the temporal dynamic of soil moisture to better understand the water-growth relationship of Pinus halepensis forests in semiarid areas. The estimates of modelled soil moisture and measured tree growth were used at four sites dominated by afforested Pinus halepensis Mill. in south-eastern Spain with 300 to 609mm mean annual precipitation. Firstly, dendrochronological samples were extracted and the widths of annual tree rings were measured to compute basal area increments (BAI). Secondly, soil moisture was estimated over 20 hydrological years (1992-2012) by means of the HYDROBAL ecohydrological model. Finally, the tree growth was linked, to mean monthly and seasonal temperature, precipitation and soil moisture. Results depict the effect of soil moisture on growth (BAI) and explain 69-73% of the variance in semiarid forests, but only 51% in the subhumid forests. This highlights the fact that that soil moisture is a suitable and promising variable to explain growth variations of afforested Pinus halepensis in semiarid conditions and useful for guiding adaptation plans to respond pro-actively to water-related global challenges. Copyright © 2016 Elsevier B.V. All rights reserved.
CONSEQUENCES OF PROTIST-STIMULATED BACTERIAL PRODUCTION FOR ESTIMATING PROTIST GROWTH EFFICIENCIES
The trophic link between bacteria and bacterivorous protists is a complex interaction that involves feedback of inorganic nutrients and growth substrates that are immediately available for prey growth. These interactions were examined in the laboratory and in incubations of conce...
Directory of Open Access Journals (Sweden)
Katherine Brill
2016-06-01
Full Text Available Manatees are routinely aged by counting Growth Layer Groups (GLGs in periotic bones (earbones. Manatee carcasses recovered in Florida between 1974 and 2010 provided age-estimation material for three readers and formed the base for a retrospective analysis of aging precision (repeatability. All readers were in good agreement (high precision with the greatest apparent source of variation being the result of earbone remodelling with increasing manatee age. Over the same period, methods of sample preparation and of determining a final age estimate changed. We examined the effects of altering methods on ease of reading GLGs and found no statistical differences. Accurate age estimates are an important component for effective management of the species and for better models of population trends and we summarize the currently recommended methods for estimating manatee ages using earbones.
Growth kinetics in multicomponent fluids
International Nuclear Information System (INIS)
Chen, S.; Lookman, T.
1995-01-01
The hydrodynamic effects on the late-stage kinetics in spinodal decomposition of multicomponent fluids are examined using a lattice Boltzmann scheme with stochastic fluctuations in the fluid and at the interface. In two dimensions, the three- and four-component immiscible fluid mixture (with a 1024 2 lattice) behaves like an off-critical binary fluid with an estimated domain growth of t 0.4 +/= 0.03 rather than t 1/3 as previously estimated, showing the significant influence of hydrodynamics. In three dimensions (with a 256 3 lattice), we estimate the growth as t 0.96 +/= 0.05 for both critical and off-critical quenches, in agreement with phenomenological theory
Oil reserves viewed from a geological and a financial perspective
International Nuclear Information System (INIS)
Mathieu, Y.; Pozzi, C.
2004-01-01
Exactly how high are the current levels of oil reserves owned by private companies in the oil sector? To what extent are the figures that they provide in their annual balance sheets reliable? Finally, what is the relationship between their declared reserves and the value of their share prices in the financial markets? In order to answer these questions, we need to consider the various links existing between on the one hand the various problems related to the technical estimation of deposits and on the other hand the economic thinking behind their use. On 22 June 2004, a discussion focusing on these themes was organised by the Centre de Geopolitique de l'Energie et des Matieres Premieres (Centre for Energy and Raw Material Geopolitics) of Dauphine University) as part of the conference: 'Oil reserves viewed from a geological and a financial perspective'. The result of the debates was clear: various methodological justifications, several accounting standards and a lack of serious monitoring have led to oil companies developing the habit of increasing the crude reserves previously declared each year, to the extent that this practice has become a virtual expectation within the financial markets. The case of Shell, a company an whose professionalism has never been called into question until last year, has clearly revealed the dangers related to this situation. The major losses in value suffered by the Anglo-Dutch company due to the brutal reaction following the unexpected downward revision of its estimated deposits provide clear proof of a latent problem. It is to be hoped that this experience will have a paradigmatic effect, bringing about a rethink of current standards with regard to the estimation of reserves, one which is more necessary today than at any time in the past. Here, we are presenting two articles providing an overview of the discussion underway and introducing two separate points of view. The first article (by Yves Mathieu of the IFP) introduces the
Uranium - raw material reserves for coming generations
International Nuclear Information System (INIS)
Keutner, H.
1981-01-01
Large uranium occurences have been discovered in the South of Mexico. The deposits are situated in the Sierra Mixteca. Reserves of 9.400 tons had been at Mexico's disposal even before these new discoveries. The quantitiy discovered recentyl amounts to 20.000 tons. The uranium reserves available apart from those in centrally controlled economic systems are presently estimated at five million tons. Meanwhile American scientists have found out that all the rivers of the world transport about 16.000 tons of uranium from the continents into the oceans per annum. The energy value of this washed out amount of uranium corresponds to the 25-fold world power demand of today. US scientists have discovered that the oceans can provide uranium for about seven million years of the present world energy demand. While the petroleum reserves decrease worldwide it seems that the exploration of uranium has just been started. (orig.) [de
[3H] Thymidine incorporation to estimate growth rates of anaerobic bacterial strains
International Nuclear Information System (INIS)
Winding, A.
1992-01-01
The incorporation of [ 3 H] thymidine by axenic cultures of anaerobic bacteria was investigated as a means to measure growth. The three fermentative strains and one of the methanogenic strains tested incorporated [ 3 H] thymidine during growth. It is concluded that the [ 3 H] thymidine incorporation method underestimates bacterial growth in anaerobic environments
US crude oil, natural gas, and natural gas liquids reserves, 1992 annual report
Energy Technology Data Exchange (ETDEWEB)
1993-10-18
This report presents estimates of proved reserves of crude oil, natural gas, and natural gas liquids as of December 31, 1992, as well as production volumes for the United States, and selected States and State subdivisions for the year 1992. Estimates are presented for the following four categories of natural gas: total gas (wet after lease separation), its two major components (nonassociated and associated-dissolved gas), and total dry gas (wet gas adjusted for the removal of liquids at natural gas processing plants). In addition, two components of natural gas liquids, lease condensate and natural gas plant liquids, have their reserves and production data presented. Also included is information on indicated additional crude oil reserves and crude oil, natural gas, and lease condensate reserves in nonproducing reservoirs. A discussion of notable oil and gas exploration and development activities during 1992 is provided.
US crude oil, natural gas, and natural gas liquids reserves, 1992 annual report
International Nuclear Information System (INIS)
1993-01-01
This report presents estimates of proved reserves of crude oil, natural gas, and natural gas liquids as of December 31, 1992, as well as production volumes for the United States, and selected States and State subdivisions for the year 1992. Estimates are presented for the following four categories of natural gas: total gas (wet after lease separation), its two major components (nonassociated and associated-dissolved gas), and total dry gas (wet gas adjusted for the removal of liquids at natural gas processing plants). In addition, two components of natural gas liquids, lease condensate and natural gas plant liquids, have their reserves and production data presented. Also included is information on indicated additional crude oil reserves and crude oil, natural gas, and lease condensate reserves in nonproducing reservoirs. A discussion of notable oil and gas exploration and development activities during 1992 is provided
Endocrine Regulation of Compensatory Growth in Fish
Directory of Open Access Journals (Sweden)
Eugene T. Won
2013-07-01
Full Text Available Compensatory growth (CG is a period of accelerated growth that occurs following the alleviation of growth-stunting conditions during which an organism can make up for lost growth opportunity and potentially catch-up in size with non-stunted cohorts. Fish show a particularly robust capacity for the response and have been the focus of numerous studies that demonstrate their ability to compensate for periods of fasting once food is made available again. Compensatory growth is characterized by an elevated growth rate resulting from enhanced feed intake, mitogen production and feed conversion efficiency. Because little is known about the underlying mechanisms that drive the response, this review describes the sequential endocrine adaptations that lead to CG; namely during the precedent catabolic phase (fasting that taps endogenous energy reserves, and the following hyperanabolic phase (refeeding when accelerated growth occurs. In order to elicit a CG response, endogenous energy reserves must first be moderately depleted, which alters endocrine profiles that enhance appetite and growth potential. During this catabolic phase, elevated ghrelin and growth hormone (GH production increase appetite and protein-sparing lipolysis, while insulin-like growth factors (IGFs are suppressed, primarily due to hepatic GH resistance. During refeeding, temporal hyperphagia provides an influx of energy and metabolic substrates that are then allocated to somatic growth by resumed IGF signaling. Under the right conditions, refeeding results in hyperanabolism and a steepened growth trajectory relative to constantly fed controls. The response wanes as energy reserves are re-accumulated and homeostasis is restored. We ascribe possible roles for select appetite and growth-regulatory hormones in the context of these catabolic and hyperanabolic phases of the CG response in teleosts, with emphasis on GH, IGFs, cortisol, somatostatin, neuropeptide Y, ghrelin and leptin.
International Nuclear Information System (INIS)
Meyer, Bettina
2012-01-01
The study on reserves for shutdown, dismantling and disposal of nuclear facilities covers the following topics: cost for shutdown, dismantling and disposal and amount and transparency of nuclear reserves, solution by y stock regulated by public law for long-term liabilities, and improvement of the protection in the event of insolvency for the remaining EVU reserves for short- and intermediate-term liabilities. The appendix includes estimations and empirical values for the cost of shutdown and dismantling, estimation of disposal costs, and a summary of Swiss studies on dismantling and disposal and transfer to Germany.
Estimating Leaching Requirements for Barley Growth under Saline Irrigation
Directory of Open Access Journals (Sweden)
Ahmed Al-Busaidi
2012-01-01
Full Text Available The utilization of marginal water resources for agriculture is receiving considerable attention. The lands irrigated with saline water are required to reduce salt accumulations through leaching and/or drainage practices. A field experiment was carried out to investigate the effect of saline irrigation and leaching fraction on barley (Hordeum vulgare L. growth. For this purpose highly saline water was diluted to the salinity levels of 3, 6 and 9 dS m-1 and applied by drip irrigation at 0.0, 0.15, 0.20 and 0.25 leaching fractions (LF. The results of the experiment showed that both quantity and quality of water regulated salts distribution within the soil in the following manner: a the salts were found higher near or immediate below the soil surface; b an enhanced LF carried more salts down the soil horizon but there was no significant difference in plant yield between different treatments of leaching fractions. Salinity of water significantly impaired barley growth. The good drainage of sandy soil enhanced the leaching process and minimized the differences between leaching fractions. The increment in saline treatments (3, 6 and 9 dS m-1 added more salts and stressed plant growth. However, the conjunctive use of marginal water at proportional LF could be effective in enhancing the yield potential of crops in water-scarce areas.
Neural electrical activity and neural network growth.
Gafarov, F M
2018-05-01
The development of central and peripheral neural system depends in part on the emergence of the correct functional connectivity in its input and output pathways. Now it is generally accepted that molecular factors guide neurons to establish a primary scaffold that undergoes activity-dependent refinement for building a fully functional circuit. However, a number of experimental results obtained recently shows that the neuronal electrical activity plays an important role in the establishing of initial interneuronal connections. Nevertheless, these processes are rather difficult to study experimentally, due to the absence of theoretical description and quantitative parameters for estimation of the neuronal activity influence on growth in neural networks. In this work we propose a general framework for a theoretical description of the activity-dependent neural network growth. The theoretical description incorporates a closed-loop growth model in which the neural activity can affect neurite outgrowth, which in turn can affect neural activity. We carried out the detailed quantitative analysis of spatiotemporal activity patterns and studied the relationship between individual cells and the network as a whole to explore the relationship between developing connectivity and activity patterns. The model, developed in this work will allow us to develop new experimental techniques for studying and quantifying the influence of the neuronal activity on growth processes in neural networks and may lead to a novel techniques for constructing large-scale neural networks by self-organization. Copyright © 2018 Elsevier Ltd. All rights reserved.
International Nuclear Information System (INIS)
Kohtoku, Shinya
1988-01-01
To examine the accuracy of digital subtraction angiographic assessment of coronary flow reserve in critical coronary stenosis, time-density curve was obtained from digital subtraction coronary angiograms for myocardial region of interest. Time to peak contrast(TPC) and time constant of the washout exponential curve(T) were measured in 14 patients with stable effort angina pectoris and critical one vessel lesion before and after percutaneous transluminal coronary angioplasty(PTCA). All patients had normal left ventricular ejection fraction (59 ± 7 %) and Tl 201 myocardial image at rest. The values of TPC and T were significantly shortened from 5.4 ± 1.3 to 4.5 ± 1.0 sec (p < 0.02) and from 10.9 ± 3.8 to 5.3 ± 1.3 sec(p < 0.001) after PTCA, respectively. However, in 9 of all patients TPC after PTCA showed approximately the same valued as those before PTCA. In 5 experimental dogs with critical circumflex stenosis, coronary flow(CF;Doppler flow meter) and systolic thickning of the posterior wall(by sonomicrometry) at rest were not different from control, however, contrast media-induced reactive hyperemia was markedly attenuated, accompanied with a significant of T (7.7 ± 4.5 vs 15.8 ± 10.9 sec, p < 0.01) and completely unchanged TPC (both 6.8 sec). With simultaneous tracing of CF and time-density curve, TPC and washout phase corresponded with contrast-induced transient CF reduction and hyperemic phase, respectively. We conclude that T might be more sensitive for estimation of CF is maintained almost normal, such as patients with stable effort angina pectoris having normal left ventricular wall motion at rest. (author)
Genomic growth curves of an outbred pig population
Directory of Open Access Journals (Sweden)
Fabyano Fonseca e Silva
2013-01-01
Full Text Available In the current post-genomic era, the genetic basis of pig growth can be understood by assessing SNP marker effects and genomic breeding values (GEBV based on estimates of these growth curve parameters as phenotypes. Although various statistical methods, such as random regression (RR-BLUP and Bayesian LASSO (BL, have been applied to genomic selection (GS, none of these has yet been used in a growth curve approach. In this work, we compared the accuracies of RR-BLUP and BL using empirical weight-age data from an outbred F2 (Brazilian Piau X commercial population. The phenotypes were determined by parameter estimates using a nonlinear logistic regression model and the halothane gene was considered as a marker for evaluating the assumptions of the GS methods in relation to the genetic variation explained by each locus. BL yielded more accurate values for all of the phenotypes evaluated and was used to estimate SNP effects and GEBV vectors. The latter allowed the construction of genomic growth curves, which showed substantial genetic discrimination among animals in the final growth phase. The SNP effect estimates allowed identification of the most relevant markers for each phenotype, the positions of which were coincident with reported QTL regions for growth traits.
DEFF Research Database (Denmark)
Ni, De Wei; Schmidt, Cristine Grings; Teocoli, Francesca
2013-01-01
The sintering behavior of porous Ce0.9Gd0.1O1.95(CGO10) tape cast layers was systematically investigated to establish fundamental kinetic parameters associated to densification and grain growth. Densification and grain growth were characterized by a set of different methods to determine the domin...... and grain boundary mobility in the porous body was estimated around 10−18–10−16m3N−1s−1 at the investigated temperature range.© 2013 Elsevier Ltd. All rights reserved.......The sintering behavior of porous Ce0.9Gd0.1O1.95(CGO10) tape cast layers was systematically investigated to establish fundamental kinetic parameters associated to densification and grain growth. Densification and grain growth were characterized by a set of different methods to determine...... the dominant sintering mechanisms and kinetics, both in isothermal and at constant heating rate (iso-rate) conditions. Densification of porous CGO10 tape is thermally activated with typical activation energy which was estimated around 440–470 kJ mol−1. Grain growth showed similar thermal activation energy...
Rahmati, Mitra; Davarynejad, Gholam Hossein; Génard, Michel; Bannayan, Mohammad; Azizi, Majid; Vercambre, Gilles
2015-01-01
In this study the sensitivity of peach tree (Prunus persica L.) to three water stress levels from mid-pit hardening until harvest was assessed. Seasonal patterns of shoot and fruit growth, gas exchange (leaf photosynthesis, stomatal conductance and transpiration) as well as carbon (C) storage/mobilization were evaluated in relation to plant water status. A simple C balance model was also developed to investigate sink-source relationship in relation to plant water status at the tree level. The C source was estimated through the leaf area dynamics and leaf photosynthesis rate along the season. The C sink was estimated for maintenance respiration and growth of shoots and fruits. Water stress significantly reduced gas exchange, and fruit, and shoot growth, but increased fruit dry matter concentration. Growth was more affected by water deficit than photosynthesis, and shoot growth was more sensitive to water deficit than fruit growth. Reduction of shoot growth was associated with a decrease of shoot elongation, emergence, and high shoot mortality. Water scarcity affected tree C assimilation due to two interacting factors: (i) reduction in leaf photosynthesis (-23% and -50% under moderate (MS) and severe (SS) water stress compared to low (LS) stress during growth season) and (ii) reduction in total leaf area (-57% and -79% under MS and SS compared to LS at harvest). Our field data analysis suggested a Ψstem threshold of -1.5 MPa below which daily net C gain became negative, i.e. C assimilation became lower than C needed for respiration and growth. Negative C balance under MS and SS associated with decline of trunk carbohydrate reserves--may have led to drought-induced vegetative mortality.
Definitions and guidelines for classification of oil and gas reserves
Energy Technology Data Exchange (ETDEWEB)
DeSorcy, G.J.; Warne, G.A.; Ashton, B.R.; Campbell, G.R.; Collyer, D.R.; Drury, J.; Lang, R.V.; Robertson, W.D.; Robinson, J.G.; Tutt, D.W
1993-05-01
The unpredictability of estimating reserves of oil and gas has made it imperative to develop a universal set of definitions and guidelines for calculating and classifying reserves. A committee of representatives from the oil and gas industry, consulting firms, industry associations, regulatory agencies, government, and financial organizations in Canada has prepared definitions of oil and gas resources and reserves, as well as a recommended classification system for those reserves. The committee believes these definitions and guidelines are suitable for use with respect to all types of oil and gas and related substances, including offshore situations and oil sands. Both deterministic and probabilistic methods are presented, as well as guidelines for specific methods including the volumetric, material balance, decline curve analysis, and reservoir simulation methods. The guidelines also consider reserves from improved recovery projects and reserves of natural gas liquids and sulfur. A glossary of terms is appended. 14 figs.
Solanki, Rekha Garg; Rajaram, Poolla; Bajpai, P. K.
2018-05-01
This work is based on the growth, characterization and estimation of lattice strain and crystallite size in CdS nanoparticles by X-ray peak profile analysis. The CdS nanoparticles were synthesized by a non-aqueous solvothermal method and were characterized by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), Raman and UV-visible spectroscopy. XRD confirms that the CdS nanoparticles have the hexagonal structure. The Williamson-Hall (W-H) method was used to study the X-ray peak profile analysis. The strain-size plot (SSP) was used to study the individual contributions of crystallite size and lattice strain from the X-rays peaks. The physical parameters such as strain, stress and energy density values were calculated using various models namely, isotropic strain model, anisotropic strain model and uniform deformation energy density model. The particle size was estimated from the TEM images to be in the range of 20-40 nm. The Raman spectrum shows the characteristic optical 1LO and 2LO vibrational modes of CdS. UV-visible absorption studies show that the band gap of the CdS nanoparticles is 2.48 eV. The results show that the crystallite size estimated from Scherrer's formula, W-H plots, SSP and the particle size calculated by TEM images are approximately similar.
Environmental degradation, energy consumption, population growth ...
African Journals Online (AJOL)
Based on the result, there is no evidence of unidirectional causality running from CO2 emissions and energy consumption to economic growth and strong unidirectional causality running from CO2 emissions, energy consumption and economic growth to population growth was found. The long run and short run estimates ...
The Growth-Inequality Association:
DEFF Research Database (Denmark)
Bjørnskov, Christian
2008-01-01
This note suggests that the association between income inequality and economic growth rates might arguably depend on the political ideology of incumbent governments. Estimates indicate that under leftwing governments, inequality is negatively associated with growth while the association is positive...... under rightwing governments. This may provide a qualification to recent studies of inequality....
International Nuclear Information System (INIS)
Iriberri, J.; Unanue, M.; Ayo, B.; Barcina, I.; Egea, L.
1990-01-01
Production and specific growth rates of attached and free-living bacteria were estimated in an oligotrophic marine system, La Salvaje Beach, Vizcaya, Spain, and in a freshwater system having a higher nutrient concentration, Butron River, Vizcaya, Spain. Production was calculated from [methyl- 3 H]thymidine incorporation by estimating specific conversion factors (cells or micrograms of C produced per mole of thymidine incorporated) for attached and free-living bacteria, respectively, in each system. Conversion factors were not statistically different between attached and free-living bacteria: 6.812 x 10 11 and 8.678 x 10 11 μg of C mol -1 for free-living and attached bacteria in the freshwater system, and 1.276 x 10 11 and 1.354 x 10 11 μg of C mol -1 for free-living and attached bacteria in the marine system. Therefore, use of a unique conversion factor for the mixed bacterial population is well founded. However, conversion factors were higher in the freshwater system than in the marine system. This could be due to the different tropic conditions of the two systems. Free-living bacteria contributed the most to production in the two systems (85% in the marine system and 67% in the freshwater system) because of their greater contribution to total biomass. Specific growth rates calculated from production data and biomass data were similar for attached and free-living bacteria
The estimation of long-run relationship between Serbian and German economic growth
Directory of Open Access Journals (Sweden)
Nikolić Ivan
2016-01-01
Full Text Available Germany has always had an essential influence on Serbia's economic development. Today, Germany is Europe's economic and political superstar so this is even more pronounced. Hence, the aim of this paper is to explore the fundamental causal relationship between German and Serbian economy. In doing so, after the introductory part, where we emphasized interconnection in terms of investment, foreign trade, employment, new technologies etc., we are extending our study using quarterly 2004q1-2015q2 GDP data of both Serbia and Germany to estimate the Vector Error Correction model (VECM. The results suggest that there is co-integration between Serbia's and Germany's economic growth. The statistically significant negative coefficient on êt-1 indicates that Serbian GDP responds to a temporary disequilibrium between the Germany and Serbia. On the other hand, Germany does not appear to respond to a disequilibrium between the two economies; the t-ratio on êt-1 is statistically insignificant. These results support the idea that economic conditions in Serbia depend on those in Germany incomparably more than conditions in Germany depend on Serbia. Despite a solid long-term impact, there is not short run causality running from GerGDP to SrbGDP.
Effects of Credit on Economic Growth, Unemployment and Poverty
Directory of Open Access Journals (Sweden)
Mangasa Augustinus Sipahutar
2016-06-01
Effect of credit on economic growth, unemployment and poverty provides evidence from Indonesia on the role of banks credit for promoting economic growth and reducing both unemployment and poverty. To document the link between banks credit and economic growth, we estimate a VAR model and variance decompositions of annual GDP per capita growth rates to examine what proxy measures of banks credit are most important in accounting for economic growth over time and how much they contribute to explaining economic growth. We also estimate an ECM to document the relationship between banks credit to both unemployment and poverty. This paper revealed bi-direction causality between banks credit and economic growth. Banks credit promotes economic growth and economic growth affects credit depth and financial development. Furthermore, banks credit is a growth accelerating factor on Indonesian economic growth. Banks credit is an endogenous growth and a good predictor on Indonesian economy. Our estimation model explained that credit allocated by banks increases business escalation to the real sectors then promotes economic growth, decreases unemployment rate through increasing in labor demanded, increases income and then decrease poverty. This overall transmission mechanism just occurred through presence of banks credit by increasing money supply to the real sectors, promotes growth and social welfare. Keywords : banks credit, economic growth, growth accelerating factor, poverty, unemployment JEL Classification : E51, E52, E58
Testing R&D-Based Endogenous Growth Models
DEFF Research Database (Denmark)
Kruse-Andersen, Peter Kjær
2017-01-01
R&D-based growth models are tested using US data for the period 1953-2014. A general growth model is developed which nests the model varieties of interest. The model implies a cointegrating relationship between multifactor productivity, research intensity, and employment. This relationship...... is estimated using cointegrated VAR models. The results provide evidence against the widely used fully endogenous variety and in favor of the semi-endogenous variety. Forecasts based on the empirical estimates suggest that the slowdown in US productivity growth will continue. Particularly, the annual long...
Gao, Xi; Kong, Bo; Vigil, R Dennis
2017-01-01
A comprehensive quantitative model incorporating the effects of fluid flow patterns, light distribution, and algal growth kinetics on biomass growth rate is developed in order to predict the performance of a Taylor vortex algal photobioreactor for culturing Chlorella vulgaris. A commonly used Lagrangian strategy for coupling the various factors influencing algal growth was employed whereby results from computational fluid dynamics and radiation transport simulations were used to compute numerous microorganism light exposure histories, and this information in turn was used to estimate the global biomass specific growth rate. The simulations provide good quantitative agreement with experimental data and correctly predict the trend in reactor performance as a key reactor operating parameter is varied (inner cylinder rotation speed). However, biomass growth curves are consistently over-predicted and potential causes for these over-predictions and drawbacks of the Lagrangian approach are addressed. Copyright © 2016 Elsevier Ltd. All rights reserved.
Impact of reserves information on formulating government policy
International Nuclear Information System (INIS)
Ekelund, M.W.; Anderson, B.; Khan, M.; Hudson, B.
1997-01-01
Policies regarding the development and production of Alberta's mineral resources such as oil, gas, and bitumen, are developed by the Alberta Ministry of Energy. The Ministry is divided into the Energy and Utilities Board (EUB) and the Department of Energy. The EUB deals with conservation, production measurement and reporting, environmental issues and some public utility issues. The Department of Energy deals with determining the appropriate fiscal and tenure regimes, market effectiveness issues and collection of Alberta's share of production. Reserve estimates are used for policy development and implementation purposes. The impact of some doubts regarding the reliability of reserves information and its impact on provincial policy recommendations were highlighted. Examples were drawn from bitumen reserves determination in the Athabasca Oil Sands area, enhanced oil recovery programs within the conventional oil sector, and royalty formulation within the conventional oil and gas sectors
Viscoelastic model of tungsten 'fuzz' growth
International Nuclear Information System (INIS)
Krasheninnikov, S I
2011-01-01
A viscoelastic model of fuzz growth is presented. The model describes the main features of tungsten fuzz observed in experiments. It gives estimates of fuzz growth rate and temperature range close to experimental ones.
Estimating non-genetic and genetic parameters of pre-weaning growth traits in Raini Cashmere goat.
Barazandeh, Arsalan; Moghbeli, Sadrollah Molaei; Vatankhah, Mahmood; Mohammadabadi, Mohammadreza
2012-04-01
Data and pedigree information used in the present study were 3,022 records of kids obtained from the breeding station of Raini goat. The studied traits were birth weight (BW), weaning weight (WW), average daily gain from birth to weaning (ADG) and Kleiber ratio at weaning (KR). The model included the fixed effects of sex of kid, type of birth, age of dam, year of birth, month of birth, and age of kid (days) as covariate that had significant effects, and random effects direct additive genetic, maternal additive genetic, maternal permanent environmental effects and residual. (Co) variance components were estimated using univariate and multivariate analysis by WOMBAT software applying four animal models including and ignoring maternal effects. Likelihood ratio test used to determine the most appropriate models. Heritability (h(a)(2)) estimates for BW, WW, ADG, and KR according to suitable model were 0.12 ± 0.05, 0.08 ± 0.06, 0.10 ± 0.06, and 0.06 ± 0.05, respectively. Estimates of the proportion of maternal permanent environmental effect to phenotypic variance (c(2)) were 0.17 ± 0.03, 0.07 ± 0.03, and 0.07 ± 0.03 for BW, WW, and ADG, respectively. Genetic correlations among traits were positive and ranged from 0.53 (BW-ADG) to 1.00 (WW-ADG, WW-KR, and ADG-KR). The maternal permanent environmental correlations between BW-WW, BW-ADG, and WW-ADG were 0.54, 0.48, and 0.99, respectively. Results indicated that maternal effects, especially maternal permanent environmental effects are an important source of variation in pre-weaning growth trait and ignoring those in the model redound incorrect genetic evaluation of kids.
Assessment of Body Reserves in Camels
Directory of Open Access Journals (Sweden)
B. Faye
2002-01-01
Full Text Available Herbivores manage their body reserves in a way that helps them respond to variations in the quality and accessibility of feed resources. Assessing these reserves provides farmers with a decision-making tool. Almost no data are available on these aspects of the camel. The present article summarizes several works on weight estimations that are used to assess the volume and weight of the hump (main location of fat reserves, relationships between hump measurements and carcass weight, and between hump weight and perirenal fat weight. Assessing the number and size of adipocytes is a means to test the relevance of these types of fat storage. There is in particular a positive relationship between the size and number of adipocytes in the hump and those in the perirenal fat. The age and sex effects were very pronounced for some of the criteria. A body condition score was established for this species based on the assessment of selected body parts. Results however showed that the hump was not a good bodycondition indicator because of variations in its weight as well as in the size of its adipocytes.
Directory of Open Access Journals (Sweden)
B. Reynolds
1998-01-01
Full Text Available A simple mass balance has been used to estimate soil calcium depletion during the growth of a 50 year old Sitka spruce crop on acid, base-poor peaty podzol soils in upland Wales. Growth of the crop will deplete the soil calcium reserve by an amount (205 kg Ca ha-1 approximately equivalent to the exchangeable calcium pool to the bottom of the profile and equal to 14% of the total soil calcium reserve to the bottom of the B horizon. Despite these predictions, measurements of exchangeable calcium show no differences beneath mature forest and acid grassland, implying that i weathering rates in forest soils are greater than long-term estimates and predictions by the PROFILE soil chemistry model ii the trees can access other sources of calcium or iii there are significant errors in the mass balance. Following stem-only harvesting, growth of a 50 year old second rotation crop will lead to further depletion of soil calcium, but this amount (79 kg Ca ha-1, is less than for a second rotation crop following whole-tree harvesting (197 kg Ca ha-1. After the first crop, stem-only harvesting would allow a further 18 rotations before depletion of the total calcium reserve to the bottom of the B horizon. Whole-tree harvesting would allow for seven rotations after the first crop. These calculations assume that all sources of calcium are equally available to the crop. This can only be resolved by dynamic modelling of the calcium cycle at the ecosystem scale based on appropriate field measurements. The potential for significant soil acidification is therefore greater following whole-tree harvesting and, in line with current recommendations (Nisbet et al., 1997, this technique should probably be avoided on acidic, nutrient-poor soils unless remedial measures are included to enhance the soil base cation status.
CSIR Research Space (South Africa)
Smakhtin, VU
2001-04-01
Full Text Available (river and groundwater) are, therefore, dependent. In this example, the assumption is that IFRs (river reserve flows) determine the extent to which groundwater resources may be impacted in the absence of any surface water resource development (the impacts... (IFRs) are used instead of reference natural streamflow time series. The corresponding groundwater storage time series will then represent the groundwater reserve. These storages may provisionally be called ?IFR driven?. Two component reserve time series...
Markets slow to develop for Niger delta gas reserves
International Nuclear Information System (INIS)
Thomas, D.
1995-01-01
Nigeria produces a very high quality, light, sweet crude oil but with a large percentage of associated gas derived from a high gas-to-oil ratio. Official proved gas reserves, both associated and nonassociated, are 120 tcf. Proved and probable reserves are estimated as high as 300 tcf. The internal market for gas has only begun to develop since the 1980s, and as a result approximately 77% of associated gas production is flared. Domestic gas consumption is currently approximately 700 MMcfd and is projected to have a medium term potential of 1.450 bcfd. The article discusses resource development, gas markets, gas flaring, gas use programs, the Bonny LNG scheme, the gas reserve base, LNG project status, competition, and energy opportunities
Forte, Vincenzo; Ferrero Colomo, Alvaro; CERN. Geneva. ATS Department
2018-01-01
In the framework of the LHC Injectors Upgrade (LIU) project [1], this document summarises the beam-based measurement of the magnetic waveform of the PS injection kicker KFA45 [2], from data collected during several Machine Development (MD) sessions in 2016 and 2017. In the first part of the document, the measurement methodology is introduced and the results presented and compared with the specification required for a clean transfer of the bunches coming from the PSB after the upgrade. These measurements represent, to date, the only way to reconstruct the magnetic waveform. In the second part, kicker magnetic waveform PSpice®[3] simulations are compared and tuned to the measurements. Finally the simulated (validated through measurements) waveforms are used to estimate the future expected emittance growth for the different PS injection schemes, both for (LIU target) LHC and fixed target beams.
Tree-growth analyses to estimate tree species' drought tolerance
Eilmann, B.; Rigling, A.
2012-01-01
Climate change is challenging forestry management and practices. Among other things, tree species with the ability to cope with more extreme climate conditions have to be identified. However, while environmental factors may severely limit tree growth or even cause tree death, assessing a tree
Testing mechanistic models of growth in insects.
Maino, James L; Kearney, Michael R
2015-11-22
Insects are typified by their small size, large numbers, impressive reproductive output and rapid growth. However, insect growth is not simply rapid; rather, insects follow a qualitatively distinct trajectory to many other animals. Here we present a mechanistic growth model for insects and show that increasing specific assimilation during the growth phase can explain the near-exponential growth trajectory of insects. The presented model is tested against growth data on 50 insects, and compared against other mechanistic growth models. Unlike the other mechanistic models, our growth model predicts energy reserves per biomass to increase with age, which implies a higher production efficiency and energy density of biomass in later instars. These predictions are tested against data compiled from the literature whereby it is confirmed that insects increase their production efficiency (by 24 percentage points) and energy density (by 4 J mg(-1)) between hatching and the attainment of full size. The model suggests that insects achieve greater production efficiencies and enhanced growth rates by increasing specific assimilation and increasing energy reserves per biomass, which are less costly to maintain than structural biomass. Our findings illustrate how the explanatory and predictive power of mechanistic growth models comes from their grounding in underlying biological processes. © 2015 The Author(s).
Stem secondary growth of tundra shrubs
DEFF Research Database (Denmark)
Campioli, Matteo; Leblans, Niki; Michelsen, Anders
2012-01-01
Our knowledge of stem secondary growth of arctic shrubs (a key component of tundra net primary production, NPP) is very limited. Here, we investigated the impact of the physical elements of the environment on shrub secondary growth by comparing annual growth rates of model species from similar...... growth (stem apical growth, stem length, and apical growth of stem plus leaves), in some cases even with opposite responses. Thus caution should be taken when estimating the impact of the environment on shrub growth from apical growth only. Integration of our data set with the (very limited) previously...
Classification of uranium reserves/resources
International Nuclear Information System (INIS)
1998-08-01
Projections of future availability of uranium to meet present and future nuclear power requirements depend on the reliability of uranium resource estimates. Lack of harmony of the definition of the different classes of uranium reserves and resources between countries makes the compilation and analysis of such information difficult. The problem was accentuated in the early 1990s with the entry of uranium producing countries from the former Soviet Union, eastern Europe and China into the world uranium supply market. The need for an internationally acceptable reserve/resource classification system and terminology using market based criteria is therefore obvious. This publication was compiled from participant's contributions and findings of the Consultants Meetings on Harmonization of Uranium Resource Assessment Concepts held in Vienna from 22 to 25 June 1992, and two Consultants Meetings on the Development of a More Meaningful Classification of Uranium Resources held in Kiev, Ukraine on 24-26 April 1995 and 20-23 August 1996. This document includes 11 contributions, summary, list of participants of the Consultants Meetings. Each contribution has been indexed and provided with an abstract
Diseases associated with growth hormone-releasing hormone receptor (GHRHR) mutations.
Martari, Marco; Salvatori, Roberto
2009-01-01
The growth hormone (GH)-releasing hormone (GHRH) receptor (GHRHR) belongs to the G protein-coupled receptors family. It is expressed almost exclusively in the anterior pituitary, where it is necessary for somatotroph cells proliferation and for GH synthesis and secretion. Mutations in the human GHRHR gene (GHRHR) can impair ligand binding and signal transduction, and have been estimated to cause about 10% of autosomal recessive familial isolated growth hormone deficiency (IGHD). Mutations reported to date include five splice donor site mutations, two microdeletions, two nonsense mutations, seven missense mutations, and one mutation in the promoter. These mutations have an autosomal recessive mode of inheritance, and heterozygous individuals do not show signs of IGHD, although the presence of an intermediate phenotype has been hypothesized. Conversely, patients with biallelic mutations have low serum insulin-like growth factor-1 and GH levels (with absent or reduced GH response to exogenous stimuli), resulting--if not treated--in proportionate dwarfism. This chapter reviews the biology of the GHRHR, the mutations that affect its gene and their effects in homozygous and heterozygous individuals. Copyright © 2009 Elsevier Inc. All rights reserved.
Assessment of Aspergillus niger biofilm growth kinetics in ...
African Journals Online (AJOL)
Jane
2011-10-12
Oct 12, 2011 ... other hand, A. niger biofilm growth followed a logistic model having higher maximal specific growth rate than ...... Growth estimation of Aspergillus oryzae cultured on ... Initial intracellular proteome profile of Aspergillus niger.
Directory of Open Access Journals (Sweden)
Zohreh Yousefi
2016-11-01
Full Text Available Introduction Small ruminants, especially native breed types, play an important role in livelihoods of a considerable part of human population in the tropics from socio-economic aspects. Therefore, integrated attempt in terms of management and genetic improvement to enhance production is of crucial importance. Knowledge of genetic variation and co-variation among traits is required for both the design of effective sheep breeding programs and the accurate prediction of genetic progress from these programs. Body weight and growth traits are one of the economically important traits in sheep production, especially in Iran where lamb sale is the main source of income for sheep breeders while other products are in secondary importance. Although mutton is the most important source of protein in Iran, meat production from the sheep does not cover the increasing consumer demand. On the other hand, increase in sheep number to increase meat production has been limited by low quality and quantity of forage range. Therefore, enhancing meat production should be achieved by selecting the animals that have maximum genetic merit as next generation parents. To design an efficient improvement program and genetic evaluation system for maximization response to selection for economically important traits, accurate estimates of the genetic parameters and the genetic relationships between the traits are necessary. Studies of various sheep breeds have shown that both direct and maternal genetic influences are of importance for lamb growth. When growth traits are included in the breeding goal, both direct and maternal genetic effects should be taken into account in order to achieve optimum genetic progress. The objective of this study was to estimate the variance components and heritability, for growth traits, by fitting six animal models in the Sangsari sheep using Gibbs sampling. Material and Method Sangsari is a fat-tailed and relatively small sized breed of sheep
Some Limits Using Random Slope Models to Measure Academic Growth
Directory of Open Access Journals (Sweden)
Daniel B. Wright
2017-11-01
Full Text Available Academic growth is often estimated using a random slope multilevel model with several years of data. However, if there are few time points, the estimates can be unreliable. While using random slope multilevel models can lower the variance of the estimates, these procedures can produce more highly erroneous estimates—zero and negative correlations with the true underlying growth—than using ordinary least squares estimates calculated for each student or school individually. An example is provided where schools with increasing graduation rates are estimated to have negative growth and vice versa. The estimation is worse when the underlying data are skewed. It is recommended that there are at least six time points for estimating growth if using a random slope model. A combination of methods can be used to avoid some of the aberrant results if it is not possible to have six or more time points.
Letcher, Benjamin H.; Schueller, Paul; Bassar, Ronald D.; Nislow, Keith H.; Coombs, Jason A.; Sakrejda, Krzysztof; Morrissey, Michael; Sigourney, Douglas B.; Whiteley, Andrew R.; O'Donnell, Matthew J.; Dubreuil, Todd L.
2015-01-01
Modelling the effects of environmental change on populations is a key challenge for ecologists, particularly as the pace of change increases. Currently, modelling efforts are limited by difficulties in establishing robust relationships between environmental drivers and population responses.We developed an integrated capture–recapture state-space model to estimate the effects of two key environmental drivers (stream flow and temperature) on demographic rates (body growth, movement and survival) using a long-term (11 years), high-resolution (individually tagged, sampled seasonally) data set of brook trout (Salvelinus fontinalis) from four sites in a stream network. Our integrated model provides an effective context within which to estimate environmental driver effects because it takes full advantage of data by estimating (latent) state values for missing observations, because it propagates uncertainty among model components and because it accounts for the major demographic rates and interactions that contribute to annual survival.We found that stream flow and temperature had strong effects on brook trout demography. Some effects, such as reduction in survival associated with low stream flow and high temperature during the summer season, were consistent across sites and age classes, suggesting that they may serve as robust indicators of vulnerability to environmental change. Other survival effects varied across ages, sites and seasons, indicating that flow and temperature may not be the primary drivers of survival in those cases. Flow and temperature also affected body growth rates; these responses were consistent across sites but differed dramatically between age classes and seasons. Finally, we found that tributary and mainstem sites responded differently to variation in flow and temperature.Annual survival (combination of survival and body growth across seasons) was insensitive to body growth and was most sensitive to flow (positive) and temperature (negative
Román-Román, Patricia; Román-Román, Sergio; Serrano-Pérez, Juan José; Torres-Ruiz, Francisco
2016-10-21
In experimental studies on tumor growth, whenever the time evolution of the relative volume of a tumor in an untreated (control) group can be fitted by a Gompertz diffusion process there is a possibility that an antiproliferative therapy, which modifies the growth rate of the process that fits the treated group, may also affect its variability. The present paper proposes several procedures for the estimation of the time function included in the infinitesimal variance of the new process, as well as the time function affecting the growth rate (which is included in the infinitesimal mean). Also, a hypothesis testing is designed to confirm or refute the need for including such a time-dependent function in the infinitesimal variance. In order to validate and compare the proposed procedures a simulation study has been carried out. In addition, a proposal is made for a strategy aimed at finding the optimal combination of procedures for each case. A real data application concerning the effects of cisplatin on a patient-derived xenograft (PDX) tumor model showcases the advantages of this model over others that have been used in the past. Copyright © 2016 Elsevier Ltd. All rights reserved.
Hirchak, Katherine A.; Murphy, Sean M.
2017-01-01
Background Opioid misuse is a large public health problem in the United States. Residents of rural areas and American Indian (AI) reservation/trust lands represent traditionally underserved populations with regard to substance-use-disorder therapy. Purpose Assess differences in the number of opioid agonist therapy (OAT) facilities and physicians with Drug Addiction Treatment Act (DATA) waivers for rural versus urban, and AI reservation/trust land versus non-AI reservation/trust land areas in Washington State. Methods The unit of analysis was the zip code. The dependent variables were the number of OAT facilities and DATA-waivered physicians in a region per 10,000 residents aged 18–64 in a zip code. A region was defined as a zip code and its contiguous zip codes. The independent variables were binary measures of whether a zip code was classified as rural versus urban, or AI reservation/trust land versus non-AI reservation/trust land. Zero-inflated negative binomial regressions with robust standard errors were estimated. Results The number of OAT clinics in a region per 10,000 zip-code residents was significantly lower in rural versus urban areas (P = .002). This did not differ significantly between AI reservation/trust land and non-AI reservation/trust land areas (P = .79). DATA-waivered physicians in a region per 10,000 zip-code residents was not significantly different between rural and urban (P = .08), or AI reservation/trust land versus non-AI reservation/trust land areas (P = .21). Conclusions It appears that the potential for Washington State residents of rural and AI reservation areas to receive OAT is similar to that of residents outside of those areas; however, difficulties in accessing therapy may remain, highlighting the importance of expanding health care insurance and providing support for DATA-waivered physicians. PMID:26987797
Fatigue Crack Growth Rate and Stress-Intensity Factor Corrections for Out-of-Plane Crack Growth
Forth, Scott C.; Herman, Dave J.; James, Mark A.
2003-01-01
Fatigue crack growth rate testing is performed by automated data collection systems that assume straight crack growth in the plane of symmetry and use standard polynomial solutions to compute crack length and stress-intensity factors from compliance or potential drop measurements. Visual measurements used to correct the collected data typically include only the horizontal crack length, which for cracks that propagate out-of-plane, under-estimates the crack growth rates and over-estimates the stress-intensity factors. The authors have devised an approach for correcting both the crack growth rates and stress-intensity factors based on two-dimensional mixed mode-I/II finite element analysis (FEA). The approach is used to correct out-of-plane data for 7050-T7451 and 2025-T6 aluminum alloys. Results indicate the correction process works well for high DeltaK levels but fails to capture the mixed-mode effects at DeltaK levels approaching threshold (da/dN approximately 10(exp -10) meter/cycle).
Bayesian modeling of Clostridium perfringens growth in beef-in-sauce products.
Jaloustre, S; Cornu, M; Morelli, E; Noël, V; Delignette-Muller, M L
2011-04-01
Models on Clostridium perfringens growth which have been published to date have all been deterministic. A probabilistic model describing growth under non-isothermal conditions was thus proposed for predicting C. perfringens growth in beef-in-sauce products cooked and distributed in a French hospital. Model parameters were estimated from different types of data from various studies. A Bayesian approach was proposed to model the overall uncertainty regarding parameters and potential variability on the 'work to be done' (h(0)) during the germination, outgrowth and lag phase. Three models which differed according to their description of this parameter h(0) were tested. The model with inter-curve variability on h(0) was found to be the best one, on the basis of goodness-of-fit assessment and validation with literature data on results obtained under non-isothermal conditions. This model was used in two-dimensional Monte Carlo simulations to predict C. perfringens growth throughout the preparation of beef-in-sauce products, using temperature profiles recorded in a hospital kitchen. The median predicted growth was 7.8×10(-2) log(10) cfu·g(-1) (95% credibility interval [2.4×10(-2), 0.8]) despite the fact that for more than 50% of the registered temperature profiles cooling steps were longer than those required by French regulations. Copyright © 2010 Elsevier Ltd. All rights reserved.
Image Analytical Approach for Needle-Shaped Crystal Counting and Length Estimation
DEFF Research Database (Denmark)
Wu, Jian X.; Kucheryavskiy, Sergey V.; Jensen, Linda G.
2015-01-01
Estimation of nucleation and crystal growth rates from microscopic information is of critical importance. This can be an especially challenging task if needle growth of crystals is observed. To address this challenge, an image analytical method for counting of needle-shaped crystals and estimating...
Job-to-job Transitions, Sorting, and Wage Growth
DEFF Research Database (Denmark)
Jinkins, David; Morin, Annaïg
unemployment, for whom the exogenous mobility assumption is not rejected, to estimate firm fixed effects. We then decompose the variance of wage growth of all job movers. We find that 66% of the variance of wage growth experienced by job movers can be attributed to variance in match quality. Expected match......We measure the contribution of match quality to the wage growth experienced by job movers. We reject the exogenous mobility assumption needed to estimate a standard fixed-effects wage regression in the Danish matched employer-employee data. We exploit the sub-sample of workers hired from...... quality growth is higher for higher-skilled occupations....
DEFF Research Database (Denmark)
Arndt, Channing; Jones, Edward Samuel; Tarp, Finn
, are being drawn on the basis of fragile evidence. This paper first assesses the aid-growth literature with a focus on recent contributions. The aid-growth literature is then framed, for the first time, in terms of the Rubin Causal Model, applied at the macroeconomic level. Our results show that aid has......The micro-macro paradox has been revived. Despite broadly positive evaluations at the micro and meso-levels, recent literature has turned decidedly pessimistic with respect to the ability of foreign aid to foster economic growth. Policy implications, such as the complete cessation of aid to Africa...... a positive and statistically significant causal effect on growth over the long run with point estimates at levels suggested by growth theory. We conclude that aid remains an important tool for enhancing the development prospects of poor nations....
International Nuclear Information System (INIS)
Klemen, Paul
1992-01-01
The cost of the Department of Energy's (DOE) Environmental Restoration (ER) Program has increased steadily over the last three years and, in the process, has drawn increasing scrutiny from Congress, the public, and government agencies such as the Office of Management and Budget and the General Accounting Office. Programmatic costs have been reviewed by many groups from within the DOE as well as from outside agencies. While cost may appear to be a universally applicable barometer of project conditions, it is actually a single dimensional manifestation of a complex set of conditions. As such, variations in cost estimates can be caused by a variety of underlying factors such as changes in scope, schedule, performing organization, economic conditions, or regulatory environment. This paper will examine the subject of cost estimates by evaluating three different cost estimates prepared for a single project including two estimates prepared by project proponents and another estimate prepared by a review team. The paper identifies the reasons for cost growth as measured by the different estimates and evaluates the ability of review estimates to measure the validity of costs. The comparative technique used to test the three cost estimates will identify the reasons for changes in the estimated cost, over time, and evaluate the ability of an independent review to correctly identify the reasons for cost growth and evaluate the reasonableness of the cost proposed by the project proponents. Recommendations are made for improved cost estimates and improved cost estimate reviews. Conclusions are reached regarding the differences in estimate results that can be attributed to differences in estimating techniques, the implications of these differences for decision makers, and circumstances that are unique to environmental cost estimating. (author)
Evaluation of SPOT imagery for the estimation of grassland biomass
Dusseux, P.; Hubert-Moy, L.; Corpetti, T.; Vertès, F.
2015-06-01
In many regions, a decrease in grasslands and change in their management, which are associated with agricultural intensification, have been observed in the last half-century. Such changes in agricultural practices have caused negative environmental effects that include water pollution, soil degradation and biodiversity loss. Moreover, climate-driven changes in grassland productivity could have serious consequences for the profitability of agriculture. The aim of this study was to assess the ability of remotely sensed data with high spatial resolution to estimate grassland biomass in agricultural areas. A vegetation index, namely the Normalized Difference Vegetation Index (NDVI), and two biophysical variables, the Leaf Area Index (LAI) and the fraction of Vegetation Cover (fCOVER) were computed using five SPOT images acquired during the growing season. In parallel, ground-based information on grassland growth was collected to calculate biomass values. The analysis of the relationship between the variables derived from the remotely sensed data and the biomass observed in the field shows that LAI outperforms NDVI and fCOVER to estimate biomass (R2 values of 0.68 against 0.30 and 0.50, respectively). The squared Pearson correlation coefficient between observed and estimated biomass using LAI derived from SPOT images reached 0.73. Biomass maps generated from remotely sensed data were then used to estimate grass reserves at the farm scale in the perspective of operational monitoring and forecasting.
Estimation of growth curve parameters in Konya Merino sheep ...
African Journals Online (AJOL)
The objective of this study was to determine the fitness of Quadratic, Cubic, Gompertz and Logistic functions to the growth curves of Konya Merino lambs obtained by using monthly records of live weight from birth to 480 days of age. The models were evaluated according to determination coefficient (R2), mean square ...
International Nuclear Information System (INIS)
Boonkitticharoen, V.; Ehrhardt, J.C.; Kirchner, P.T.
1989-01-01
Quantitative measurement of bacterial growth may be made using a radioassay technique. This method measures, by scintillation counting, the 14 CO 2 derived from the bacterial metabolism of a 14 C-labeled substrate. Mathematical growth models may serve as reliable tools for estimation of the generation rate constant (or slope of the growth curve) and provide a basis for evaluating assay performance. Two models, i.e., exponential and logistic, are proposed. Both models yielded an accurate fit to the data from radioactive measurement of bacterial growth. The exponential model yielded high precision values of the generation rate constant, with an average relative standard deviation of 1.2%. Under most conditions the assay demonstrated no changes in the slopes of growth curves when the number of bacteria per inoculation was changed. However, the radiometric assay by scintillation method had a growth-inhibiting effect on a few strains of bacteria. The source of this problem was thought to be hypersensitivity to trace amounts of toluene remaining on the detector
On the growth estimates of entire functions of double complex variables
Directory of Open Access Journals (Sweden)
Sanjib Datta
2017-08-01
Full Text Available Recently Datta et al. (2016 introduced the idea of relative type and relative weak type of entire functions of two complex variables with respect to another entire function of two complex variables and prove some related growth properties of it. In this paper, further we study some growth properties of entire functions of two complex variables on the basis of their relative types and relative weak types as introduced by Datta et al (2016.
Kiserud, Torvid; Benachi, Alexandra; Hecher, Kurt; Perez, Rogelio González; Carvalho, José; Piaggio, Gilda; Platt, Lawrence D
2018-02-01
weight was strongest on the lowest percentiles and smallest on the highest percentiles for estimated fetal weight. (3) When adjustment was made for maternal covariates, there was still a significant effect of country as covariate that indicated that ethnic, cultural, and geographic variation play a role. (4) Variation between populations was not restricted to fetal size because there were also differences in growth trajectories. (5) The wide physiologic ranges, as illustrated by the 5th-95th percentile for estimated fetal weight being 2205-3538 g at 37 weeks gestation, signify that human fetal growth under optimized maternal conditions is not uniform. Rather, it has a remarkable variation that largely is unexplained by commonly known factors. We suggest this variation could be part of our common biologic strategy that makes human evolution extremely successful. The World Health Organization fetal growth charts are intended to be used internationally based on low-risk pregnancies from populations in Africa, Asia, Europe, and South America. We consider it prudent to test and monitor whether the growth charts' performance meets the local needs, because refinements are possible by a change in cut-offs or customization for fetal sex, maternal factors, and populations. In the same line, the study finding of variations emphasizes the need for carefully adjusted growth charts that reflect optimal local growth when public health issues are addressed. Copyright © 2017 Elsevier Inc. All rights reserved.
Electricity regulation and economic growth
Costa, M. Teresa (Maria Teresa), 1951-; Garcia-Quevedo, Jose; Trujillo-Baute, Elisa
2018-01-01
The main objective of this paper is to analyse the effect of electricity regulation on economic growth. Although the relationship between electricity consumption and economic growth has been extensively analysed in the empirical literature, this framework has not been used to estimate the effect of electricity regulation on economic growth. Understanding this effect is essential for the assessment of regulatory policy. Specifically, we assess the effects of two major areas of regulation, rene...
Directory of Open Access Journals (Sweden)
Salwani S.
2012-06-01
Full Text Available Biological Nitrogen Fixation (BNF process benefits the agriculture sector especially for reducing cost of nitrogenfertilizer. In the process, the diazotrophs convert N2 into ammonia (NH3 which is useable by plants. The BNF process iscatalysed by nitrogenase enzyme that involved protons and electrons together with evolution of H2 therefore, theassessment of N2 fixation is also available via H2 production and electron allocation analysis. Thus, the aims of thisexperiment were to estimate the nitrogenase enzyme activities and observe the influence of diazothrophs on growth oflegume (soybean and non legume (rice plants. Host plants were inoculated with respective inocula; Bradyrhizobiumjaponicum (strain 532C for soybean while Azospirillum brasilense (Sp7 and locally isolated diazotroph (isolate 5 forrice. At harvest, the plants were observed for plant growth parameters, H2 evolution, N2 fixation and electron allocationcoefficient (EAC values. The experiment recorded N2 fixation activities of inoculated soybean plants at 141.2 μmol N2 h-1g-1 dry weight nodule, and the evolution of H2 at 144.4 μmol H2 h-1 g-1 dry weight nodule. The electron allocationcoefficient (EAC of soybean was recorded at 0.982. For inoculated rice plants, none of the observations was successfully recorded. However, results for chlorophyll contents and plant dry weight of both plants inoculated with respective inocula were similar to the control treatments supplied with full nitrogen fertilization (+N. The experiment clearly showed that inoculation of diazotrophic bacteria could enhance growth of the host plants similar to plants treated with nitrogenous fertilizer due to efficient N2 fixation process
OPTIMUM VOLUME OF BANK RESERVE: FORECASTING OF OVERDUE CREDIT INDEBTEDNESS USING COPULA MODELS
Directory of Open Access Journals (Sweden)
Kazakova K. A.
2015-12-01
Full Text Available The article propose to consider the possibility of RLUF-copulas application for the creation of joint distributions of overdue credit indebtedness ranks with macroeconomic indicators for the purpose of indebtedness forecasting and also for the definition of optimum volumes of reserve requirements for the corresponding losses. In this research the comparative analysis of multivariate distributions of RLUF-copula estimation with such classical copulas, as FGM-copula, Frank's copula and Gauss's copula is made. In the article the method of maximum likelihood is used for receiving estimates of model parameters. In case of RLUF-copula Bayesian estimates of parameters are received using the Metropolis algorithm with random volatility. Forecasting of bank reserve volumes for all received models is executed in the form of random sample generation by the means of the algorithm of acceptance-deviation for the creation of the corresponding sample of joint distribution using the copula density function. As the result of playing of hundred possible scenarios of indebtedness volumes is obtained the 95 % confidence level for the possible volume of credit indebtedness which can fully act as the optimum volume of reserve requirements for the corresponding credit losses.
75 FR 66271 - Assessment Dividends, Assessment Rates and Designated Reserve Ratio
2010-10-27
... sufficiently large fund and stable premiums is most apparent. Memories of the last two crises will fade and the... deposit and assessment base growth (using adjusted total domestic deposits). Implied forward interest... the analysis into the future, using estimates based on implied forward interest rates and assuming...
Active power reserves evaluation in large scale PVPPs
DEFF Research Database (Denmark)
Crăciun, Bogdan-Ionut; Kerekes, Tamas; Sera, Dezso
2013-01-01
The present trend on investing in renewable ways of producing electricity in the detriment of conventional fossil fuel-based plants will lead to a certain point where these plants have to provide ancillary services and contribute to overall grid stability. Photovoltaic (PV) power has the fastest...... growth among all renewable energies and managed to reach high penetration levels creating instabilities which at the moment are corrected by the conventional generation. This paradigm will change in the future scenarios where most of the power is supplied by large scale renewable plants and parts...... of the ancillary services have to be shared by the renewable plants. The main focus of the proposed paper is to technically and economically analyze the possibility of having active power reserves in large scale PV power plants (PVPPs) without any auxiliary storage equipment. The provided reserves should...
Energy Technology Data Exchange (ETDEWEB)
Hardage, B.A.; Carr, D.L.; Finley, R.J.; Tyler, N.; Lancaster, D.E.; Elphick, R.Y.; Ballard, J.R.
1995-07-01
The objectives of this project are to define undrained or incompletely drained reservoir compartments controlled primarily by depositional heterogeneity in a low-accommodation, cratonic Midcontinent depositional setting, and, afterwards, to develop and transfer to producers strategies for infield reserve growth of natural gas. Integrated geologic, geophysical, reservoir engineering, and petrophysical evaluations are described in complex difficult-to-characterize fluvial and deltaic reservoirs in Boonsville (Bend Conglomerate Gas) field, a large, mature gas field located in the Fort Worth Basin of North Texas. The purpose of this project is to demonstrate approaches to overcoming the reservoir complexity, targeting the gas resource, and doing so using state-of-the-art technologies being applied by a large cross section of Midcontinent operators.
Social and economic factors of the natural risk growth: estimation of the Russian regions
Petrova, E.
2003-04-01
Òhe vulnerability of the population and economy territorial complexes (PETC) to the influence of unfavorable and dangerous natural processes and events is determined not only by the physical parameters of natural hazards in the given region, but also by economic and social peculiarities of the PETC by itself. It depends on economy type, on PETC’s age, structure and dimensions as well as on degree of its participation in the territorial division of labor. PETC would be more vulnerable to the natural hazards impact if its population density, concentration of the industrial capacities (especially of the objects that additionally create the potential danger of the man-caused catastrophes such as nuclear-power stations, chemical enterprises, oil refineries and so on), concentration of transport and other means of communication, the technological complexity, the originality of the objects included in it as well as the originality of PETC by itself would be higher. The PETC with the unfavorable socio-political and ecological situation and underdeveloped management structures are more vulnerable. The estimation of regions by PETC vulnerability degree to the natural hazards were marked out on a base of data about the actual distribution of the natural hazards in Russia and analysis of the economic indices of the Russian Federation subjects. Among the economic indexes the per capita production of Gross Regional Product (GRP), population density, road density, the degree of appraisal depreciation of the fixed assets, the land cultivation degree of the territory, forest share and so on were taken into account. As the analysis showed, the economic and social factors of the natural risk growth are active in the majority of the regions of the Russian Federation. Such a situation demands the increased attention of state and local authorities to this problem for lowering the economic and social constituents of the growth of natural hazards.
Estimation of algal colonization growth on mortar surface using a ...
Indian Academy of Sciences (India)
Thu-Hien Tran
a hybridization of machine learning and metaheuristic optimization ... support vector regression (LS-SVR) for modelling the growth time of the green alga Klebsormidium flaccidum ...... 2012 Landslide susceptibility assessment in the Hoa Binh.
Classification system of the mineral reserves and resources of Ukraine
International Nuclear Information System (INIS)
Lovinyukov, V.I.
1998-01-01
This paper describes the system used to classify the resources and reserves of all minerals and fuels in Ukraine. The classification system is part of an official procedure determined by the Ukrainian State Commission on Reserves. Following preparation of resource estimates the results are registered with the State, which maintains an official inventory of all mineral resources. This paper compares the Ukrainian system to, and finds it compatible with the United Nations International Framework of resource classification. The UN system is based on economics of production and mineability. (author)
Classification system of the mineral reserves and resources of Ukraine
International Nuclear Information System (INIS)
Lovyunikov, V.I.
1997-01-01
This paper describes the system used to classify the resources and reserves of all minerals and fuels in Ukraine. The classification system is part of an official procedures determined by the Ukrainian State Commission on Reserves. Following preparation of resource estimates the results are registered with the State, which maintains an official inventory of all mineral resources. This paper compares the Ukrainian system to, and finds it compatible with the United Nations International Framework of resources classification. The UN system is based on economics of production and mineability. (author). 1 tab
Corruption's effect on growth and its transmission channels
Pellegrini, L.; Gerlagh, R.
2004-01-01
A common finding of recent theoretical and empirical literature is that corruption has a negative effect on economic growth. In the paper, through growth regression analysis, we estimate the direct and indirect effects of corruption on economic growth. The indirect transmission channels,
Demand for Reserves and the Central Bank's Management of Interest Rates
Martin Schlegel; Sébastien Kraenzlin
2009-01-01
The implementation of monetary policy is prevalently done by interest rate targeting with a short term market rate serving as operational target. The instruments for achieving the operational target are the provision of reserves and the interest rate charged in these transactions. This paper presents a model for the estimation of the demand curve for reserves, derived from the central bank's fixed rate tender auction and the interbank money market. Using data from Switzerland, the slope of th...
Luppens, James A.; Scott, David C.
2015-01-01
This report presents the final results of the first assessment of both coal resources and reserves for all significant coal beds in the entire Powder River Basin, northeastern Wyoming and southeastern Montana. The basin covers about 19,500 square miles, exclusive of the part of the basin within the Crow and Northern Cheyenne Indian Reservations in Montana. The Powder River Basin, which contains the largest resources of low-sulfur, low-ash, subbituminous coal in the United States, is the single most important coal basin in the United States. The U.S. Geological Survey used a geology-based assessment methodology to estimate an original coal resource of about 1.16 trillion short tons for 47 coal beds in the Powder River Basin; in-place (remaining) resources are about 1.15 trillion short tons. This is the first time that all beds were mapped individually over the entire basin. A total of 162 billion short tons of recoverable coal resources (coal reserve base) are estimated at a 10:1 stripping ratio or less. An estimated 25 billion short tons of that coal reserve base met the definition of reserves, which are resources that can be economically produced at or below the current sales price at the time of the evaluation. The total underground coal resource in coal beds 10–20 feet thick is estimated at 304 billion short tons.
Mtimet, Narjes; Guégan, Stéphanie; Durand, Lucile; Mathot, Anne-Gabrielle; Venaille, Laurent; Leguérinel, Ivan; Coroller, Louis; Couvert, Olivier
2016-05-01
Thermophilic spore-forming bacteria are potential contaminants in several industrial sectors involving high temperatures (40-65 °C) in the manufacturing process. Among those thermophilic spore-forming bacteria, Thermoanaerobacterium thermosaccharolyticum, called "the swelling canned food spoiler", has generated interest over the last decade in the food sector. The aim of this study was to investigate and to model pH effect on growth, heat resistance and recovery abilities after a heat-treatment of T. thermosaccharolyticum DSM 571. Growth and sporulation were conducted on reinforced clostridium media and liver broth respectively. The highest spore heat resistances and the greatest recovery ability after a heat-treatment were obtained at pH condition allowing maximal growth rate. Growth and sporulation boundaries were estimated, then models using growth limits as main parameters were extended to describe and quantify the effect of pH on recovery of injured spores after a heat-treatment. So, cardinal values were used as a single set of parameters to describe growth, sporulation and recovery abilities. Besides, this work suggests that T. thermosaccharolyticum preserve its ability for germination and outgrowth after a heat-treatment at a low pH where other high resistant spore-forming bacteria like Geobacillus stearothermophilus are unable to grow. Copyright © 2015 Elsevier Ltd. All rights reserved.
Export Specialisation and Local Economic Growth
Naude, Wim; Bosker, Maarten; Matthee, Marianne
This paper aims to provide empirical evidence on whether export specialization or diversification is better for local economic growth. Using export data from 354 magisterial districts of South Africa for 1996 and 2001 we estimate spatial growth regressions that include measures of the degree of
Political Instability and Economic Growth
Alberto Alesina; Sule Ozler; Nouriel Roubini; Phillip Swagel
1992-01-01
This paper investigates the relationship between political instability and per capita GDP growth in a sample of 113 countries for the period 1950-1982. We define ?political instability? as the propensity of a government collapse, and we estimate a model in which political instability and economic growth are jointly determined. The main result of this paper is that in countries and time periods with a high propensity of government collapse, growth is significantly lower than otherwise. This ef...
Urban climate modifies tree growth in Berlin
Dahlhausen, Jens; Rötzer, Thomas; Biber, Peter; Uhl, Enno; Pretzsch, Hans
2018-05-01
Climate, e.g., air temperature and precipitation, differs strongly between urban and peripheral areas, which causes diverse life conditions for trees. In order to compare tree growth, we sampled in total 252 small-leaved lime trees ( Tilia cordata Mill) in the city of Berlin along a gradient from the city center to the surroundings. By means of increment cores, we are able to trace back their growth for the last 50 to 100 years. A general growth trend can be shown by comparing recent basal area growth with estimates from extrapolating a growth function that had been fitted with growth data from earlier years. Estimating a linear model, we show that air temperature and precipitation significantly influence tree growth within the last 20 years. Under consideration of housing density, the results reveal that higher air temperature and less precipitation led to higher growth rates in high-dense areas, but not in low-dense areas. In addition, our data reveal a significantly higher variance of the ring width index in areas with medium housing density compared to low housing density, but no temporal trend. Transferring the results to forest stands, climate change is expected to lead to higher tree growth rates.
Urban climate modifies tree growth in Berlin
Dahlhausen, Jens; Rötzer, Thomas; Biber, Peter; Uhl, Enno; Pretzsch, Hans
2017-12-01
Climate, e.g., air temperature and precipitation, differs strongly between urban and peripheral areas, which causes diverse life conditions for trees. In order to compare tree growth, we sampled in total 252 small-leaved lime trees (Tilia cordata Mill) in the city of Berlin along a gradient from the city center to the surroundings. By means of increment cores, we are able to trace back their growth for the last 50 to 100 years. A general growth trend can be shown by comparing recent basal area growth with estimates from extrapolating a growth function that had been fitted with growth data from earlier years. Estimating a linear model, we show that air temperature and precipitation significantly influence tree growth within the last 20 years. Under consideration of housing density, the results reveal that higher air temperature and less precipitation led to higher growth rates in high-dense areas, but not in low-dense areas. In addition, our data reveal a significantly higher variance of the ring width index in areas with medium housing density compared to low housing density, but no temporal trend. Transferring the results to forest stands, climate change is expected to lead to higher tree growth rates.
Energy Technology Data Exchange (ETDEWEB)
NONE
2008-07-01
For the French, whose last coal mine closed in 2004, the 'comeback' of coal as a political issue may seem a bit surprising. Even if coal is still used in domestic industry and to produce electricity, it is many years since it was used as the primary energy source for electricity production. This situation, specific to France and certain European countries, is not at all typical of the world situation: in the face of surging energy demand, coal - whose reserves have been estimated by the World Energy Council to cover 145 years of consumption at the current rate - seems to be an energy of the future and an alternative to oil, natural gas and nuclear power for the production of electricity.
Planning outstanding reserves in general insurance
Raeva, E.; Pavlov, V.
2017-10-01
Each insurance company have to ensure its solvency through presentation of accounts for its own reserves in the start of the year. Usually the task of the actuary is to estimate the state of the company on an annual basis and the expectation of the status of the company for a future period. One of the major problem when calculating the liabilities of the incurred claims, is related to the delay of payments. Object of consideration in the present note are the outstanding claim reserves, which are set aside to cover claims, occurred before the date of the annual account, but still not paid, and related with them expenses. There may be different reasons for the delay of claims settlement. For example, continuation the process of the liquidation of the damage waiting for necessary documents or the presence of controversial cases whose permission takes time, etc. Thus the claims, which determine the outstanding reserves could be divided in the following types: claims, which are reported, but not settled (RBNS); claims, which are incurred but not reported (IBNR); claims, whose case is finished, but it is possible to be reopened. When calculating the reserves for IBNR claims, most widely used is the Chain-ladder method and its modification presented by the Bornhuetter - Ferguson method. For modeling the outstanding claims, the available data should be presented in so called run-off triangle, which underlies in the basis of such methods. The present work provides a review of the algorithm for calculating insurance outstanding claim reserves according to the Chain-ladder method. Using available data for claims related to liability of drivers, registered in Bulgaria an example is constructed to illustrate the methodology of the Chain-Ladder method. Back-testing approach is used for validating the results.
Antigen-Addicted T Cell Reserves Trickle Charge the Frontline Killers.
Kalia, Vandana; Sarkar, Surojit
2016-07-19
Highly active killer T cells mediate a stable standoff during controlled persistent infections. In this issue of Immunity, Robey and colleagues describe a unique antigen-addicted T cell population bearing characteristics of both effector and memory CD8(+) T cells that provides a continuous supply of potent killer T cells to curb Toxoplasma gondii growth during latency. Copyright © 2016 Elsevier Inc. All rights reserved.
Worker remittances, migration, accumulation and growth in poor developing countries
Ziesemer, T.H.W.
2008-01-01
The impact of migration and worker remittances on literacy, accumulation of capital and growth is analyzed for a panel of countries with per capita income below $1200 (2000). We estimate regressions for dynamic equations of migration, worker remittances, savings, investment, tax revenues, public expenditure on education, interest rates, literacy, labour force growth, development aid and GDP per capita growth, using dynamic panel data methods. The estimated equations are then integrated to a d...
Analysing growth and development of plants jointly using developmental growth stages.
Dambreville, Anaëlle; Lauri, Pierre-Éric; Normand, Frédéric; Guédon, Yann
2015-01-01
Plant growth, the increase of organ dimensions over time, and development, the change in plant structure, are often studied as two separate processes. However, there is structural and functional evidence that these two processes are strongly related. The aim of this study was to investigate the co-ordination between growth and development using mango trees, which have well-defined developmental stages. Developmental stages, determined in an expert way, and organ sizes, determined from objective measurements, were collected during the vegetative growth and flowering phases of two cultivars of mango, Mangifera indica. For a given cultivar and growth unit type (either vegetative or flowering), a multistage model based on absolute growth rate sequences deduced from the measurements was first built, and then growth stages deduced from the model were compared with developmental stages. Strong matches were obtained between growth stages and developmental stages, leading to a consistent definition of integrative developmental growth stages. The growth stages highlighted growth asynchronisms between two topologically connected organs, namely the vegetative axis and its leaves. Integrative developmental growth stages emphasize that developmental stages are closely related to organ growth rates. The results are discussed in terms of the possible physiological processes underlying these stages, including plant hydraulics, biomechanics and carbohydrate partitioning. © The Author 2014. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com.
Estimation of genetic parameters for growth traits in Brangus cattle
African Journals Online (AJOL)
p2492989
3Agricultural Business Research Institute, UNE Armidale NSW 2351, ... Table 1 Descriptive statistics of data after editing that were used in the .... Variance components due to direct and maternal effects for growth traits of Australian beef cattle.
On the analysis of Canadian Holstein dairy cow lactation curves using standard growth functions.
López, S; France, J; Odongo, N E; McBride, R A; Kebreab, E; AlZahal, O; McBride, B W; Dijkstra, J
2015-04-01
Six classical growth functions (monomolecular, Schumacher, Gompertz, logistic, Richards, and Morgan) were fitted to individual and average (by parity) cumulative milk production curves of Canadian Holstein dairy cows. The data analyzed consisted of approximately 91,000 daily milk yield records corresponding to 122 first, 99 second, and 92 third parity individual lactation curves. The functions were fitted using nonlinear regression procedures, and their performance was assessed using goodness-of-fit statistics (coefficient of determination, residual mean squares, Akaike information criterion, and the correlation and concordance coefficients between observed and adjusted milk yields at several days in milk). Overall, all the growth functions evaluated showed an acceptable fit to the cumulative milk production curves, with the Richards equation ranking first (smallest Akaike information criterion) followed by the Morgan equation. Differences among the functions in their goodness-of-fit were enlarged when fitted to average curves by parity, where the sigmoidal functions with a variable point of inflection (Richards and Morgan) outperformed the other 4 equations. All the functions provided satisfactory predictions of milk yield (calculated from the first derivative of the functions) at different lactation stages, from early to late lactation. The Richards and Morgan equations provided the most accurate estimates of peak yield and total milk production per 305-d lactation, whereas the least accurate estimates were obtained with the logistic equation. In conclusion, classical growth functions (especially sigmoidal functions with a variable point of inflection) proved to be feasible alternatives to fit cumulative milk production curves of dairy cows, resulting in suitable statistical performance and accurate estimates of lactation traits. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.
DEFF Research Database (Denmark)
Doucouliagos, Hristos; Paldam, Martin
The AEL (aid effectiveness literature) is econo¬metric studies of the macroeconomic effects of development aid. It contains about 100 papers of which 68 are reduced form estimates of theeffect of aid on growth in the recipient country. The raw data show that growth is unconnected to aid......, but the AEL has put so much structure on the data that all results possible have emerged. The present meta study considers both the best-set of the 68 papers and the all-set of 543 regressions published. Both sets have a positive average aid-growth elasticity, but it is small and insignificant: The AEL has...... betweenstudies is real. In particular, the aid-growth association is stronger for Asian countries, and the aid-growth association is shown to have been weaker in the 1970s....
Urdaibai Biosphere Reserve (Biscay, Spain): Conservation against development?
Castillo-Eguskitza, Nekane; Rescia, Alejandro J; Onaindia, Miren
2017-08-15
The protected area approach has extended from conserving biodiversity to improving human well-being. However, the relationship between conservation and socioeconomic and cultural development continues to be controversial. This paper combines land use variables with socioeconomic and cultural variables through multivariate ordination analysis and evaluates their evolution in two areas inside and outside a Biosphere Reserve since the approval of the Governance Plan for Use and Management in the Reserve. The results indicate a similar tendency in the two areas, from the abandonment of traditional rural activities and decline in pine plantations to naturalness, urban sprawl and the growth of the tertiary economic sector, welfare indicators and sustainability index. However, it can be broadly observed that the region included inside the protected area presents better conservation features (native forest) and rural systems (forestry and primary economic sector) than the region outside the protected area while maintaining similar socioeconomic and cultural conditions. We suggest that the designation of the Biosphere Reserve does not influence the local population negatively but does safeguard its conservation, which could have enhanced socioeconomic and cultural development. Thus, even though certain changes must be made to replace the conifer plantations and encourage agricultural activities, the designation of the protected area fulfills its sustainability goal and enhances the local population's quality of life. Copyright © 2017 Elsevier B.V. All rights reserved.
The Dynamic Effects of Entrepreneurship on Regional Economic Growth
DEFF Research Database (Denmark)
Matejovsky, Lukas; Mohapatra, Sandeep; Steiner, Bodo
2014-01-01
This study explores the temporal pattern of income disparity for Canadian provinces in two estimation steps. First, an econometric growth regression model is applied to identify the impact of entrepreneurship on regional economic growth. The estimation results suggest that entrepreneurship......, measured in terms of the selfemployment rate, plays a pivotal role in determining regional development in Canada. Second, a dynamic vector autoregression (VAR) model is employed to predict the long-run regional growth effects that result from policy shocks affecting entrepreneurship. Compared to other...... growth drivers, entrepreneurship is found to have more pronounced and long-term stimulative effects on regional development for the period of 1987 to 2007...
Job-to-Job Transitions, Sorting, and Wage Growth
DEFF Research Database (Denmark)
Jinkins, David; Morin, Annaïg
in the quality of the worker-firm match rather than transitions to better firms. Also, 66% of the variance of wage growth experienced by job movers can be attributed to variance in match quality. Expected match quality growth is higher for higher-skilled occupations and high-educated workers.......In this paper, we measure the contribution of match quality to the wage growth experienced by job movers. Using the Danish matched employer-employee data, we reject the exogenous mobility assumption needed to estimate a standard fixedeffects wage regression. To estimate firm fixed effects, we...... exploit the sub-sample of workers hired from unemployment, for whom the exogenous mobility assumption is not rejected. Then we decompose the mean and the variance of wage growth of jobto-job movers. We find that most of the wage growth experienced by job movers is attributable to an improvement...
Greco, Mariana; Pardo, Alejandro; Pose, Graciela; Patriarca, Andrea
Xerophilic fungi represent a serious problem due to their ability to grow at low water activities causing the spoiling of low and intermediate moisture foods, stored goods and animal feeds, with the consequent economic losses. The combined effect of water activity and temperature of four Eurotium species isolated from animal feeds was investigated. Eurotium amstelodami, Eurotium chevalieri, Eurotium repens and Eurotium rubrum were grown at 5, 15, 25, 37 and 45°C on malt extract agar adjusted with glycerol in the range 0.710-0.993 of water activities. The cardinal model proposed by Rosso and Robinson (2001) was applied to fit growth data, with the variable water activity at fixed temperatures, obtaining three cardinal water activities (a wmin , a wmax , a wopt ) and the specific growth rate at the optimum a w (μ opt ). A probabilistic model was also applied to define the interface between growth and no-growth. The cardinal model provided an adequate estimation of the optimal a w to grow and the maximum growth rate. The probabilistic model showed a good performance to fit growth/no-growth cases in the predicted range. The results presented here could be applied to predict Eurotium species growth in animal feeds. Copyright © 2017 Asociación Española de Micología. Publicado por Elsevier España, S.L.U. All rights reserved.
Directory of Open Access Journals (Sweden)
Hasan Mohammed Hameed
2017-02-01
Full Text Available The growth and spread of impervious surfaces within urbanizing catchment areas pose signiificant threats to the quality of natural and built-up environments. Impervious surfaces prevent water infiltration into the soil, resulting in increased runoff generation. The Erbil Sub-basin was selected because the impervious cover is increasing rapidly and is affecting the hydrological condition of the watershed. The overall aim of this study is to examine the impact of urban growth and other changes in land use on runoff response during the study period of 1984 to 2014. The study describes long-term hydrologic responses within the rapidly developing catchment area of Erbil city, in the Kurdistan Region of Iraq. Data from six rainfall stations in and around the Erbil Sub-basin were used. A Digital Elevation Model (DEM was also used to extract the distribution of the drainage network. Historical levels of urban growth and the corresponding impervious areas, as well as land use/land cover changes were mapped from 1984 to 2014 using a temporal satellite image (Landsat to determine land use/land cover changes. Land use/land cover was combined with a hydrological model (SCS-CN to estimate the volume of runoff from the watershed. The study indicates that the urbanization of the watershed has increased the impervious land cover by 71% for the period from 1984 to 2004 and by 51% from 2004 to 2014. The volume of runoff was 85% higher in 2014 as compared to 1984 due to the increase in the impervious surface area; this is attributed to urban growth. The study also points out that the slope of the watershed in the Erbil sub-basin should be taken into account in surface runoff estimation as the upstream part of the watershed has a high gradient and the land is almost barren with very little vegetation cover; this causes an increase in the velocity of the flow and increases the risk of flooding in Erbil city.
Nonlinear Growth Curves in Developmental Research
Grimm, Kevin J.; Ram, Nilam; Hamagami, Fumiaki
2011-01-01
Developmentalists are often interested in understanding change processes and growth models are the most common analytic tool for examining such processes. Nonlinear growth curves are especially valuable to developmentalists because the defining characteristics of the growth process such as initial levels, rates of change during growth spurts, and asymptotic levels can be estimated. A variety of growth models are described beginning with the linear growth model and moving to nonlinear models of varying complexity. A detailed discussion of nonlinear models is provided, highlighting the added insights into complex developmental processes associated with their use. A collection of growth models are fit to repeated measures of height from participants of the Berkeley Growth and Guidance Studies from early childhood through adulthood. PMID:21824131
Fish growth parameters are commonly estimated from the counts of ...
African Journals Online (AJOL)
spamer
>300 mm TL were tagged with external plastic dart tags, 89 mm long ... lithognathus were compared to predictions from growth models based on otolith ring counts. Galjoen ..... On the other hand, a new type of bio-compatible tag, which does ...
Brill, Katherine; Marmontel, Miriam; Bolen-Richardson, Meghan; Stewart, Robert EA
2016-01-01
Manatees are routinely aged by counting Growth Layer Groups (GLGs) in periotic bones (earbones). Manatee carcasses recovered in Florida between 1974 and 2010 provided age-estimation material for three readers and formed the base for a retrospective analysis of aging precision (repeatability). All readers were in good agreement (high precision) with the greatest apparent source of variation being the result of earbone remodelling with increasing manatee age. Over the same period, methods of sa...
Poverty, growth, inequality and pro-poor factors : new evidence from macro data
Amini, Chiara; Dal Bianco, Silvia
2016-01-01
Does economic growth reduce poverty? If so, by how much? How economic inequality affects poverty? Does the responsiveness of poverty to growth and inequality depend on initial poverty and inequality? How do pro-poor policies influence the poverty-growth-inequality nexus? \\ud \\ud This paper provides novel quantitative answers to such questions. In particular, the System Generalised Method of Moments estimator is employed to estimate the intertwined relation between poverty, growth, inequality ...
Characterizing the reproduction number of epidemics with early subexponential growth dynamics.
Chowell, Gerardo; Viboud, Cécile; Simonsen, Lone; Moghadas, Seyed M
2016-10-01
Early estimates of the transmission potential of emerging and re-emerging infections are increasingly used to inform public health authorities on the level of risk posed by outbreaks. Existing methods to estimate the reproduction number generally assume exponential growth in case incidence in the first few disease generations, before susceptible depletion sets in. In reality, outbreaks can display subexponential (i.e. polynomial) growth in the first few disease generations, owing to clustering in contact patterns, spatial effects, inhomogeneous mixing, reactive behaviour changes or other mechanisms. Here, we introduce the generalized growth model to characterize the early growth profile of outbreaks and estimate the effective reproduction number, with no need for explicit assumptions about the shape of epidemic growth. We demonstrate this phenomenological approach using analytical results and simulations from mechanistic models, and provide validation against a range of empirical disease datasets. Our results suggest that subexponential growth in the early phase of an epidemic is the rule rather the exception. Mechanistic simulations show that slight modifications to the classical susceptible-infectious-removed model result in subexponential growth, and in turn a rapid decline in the reproduction number within three to five disease generations. For empirical outbreaks, the generalized-growth model consistently outperforms the exponential model for a variety of directly and indirectly transmitted diseases datasets (pandemic influenza, measles, smallpox, bubonic plague, cholera, foot-and-mouth disease, HIV/AIDS and Ebola) with model estimates supporting subexponential growth dynamics. The rapid decline in effective reproduction number predicted by analytical results and observed in real and synthetic datasets within three to five disease generations contrasts with the expectation of invariant reproduction number in epidemics obeying exponential growth. The
Characterizing the reproduction number of epidemics with early subexponential growth dynamics
Viboud, Cécile; Simonsen, Lone; Moghadas, Seyed M.
2016-01-01
Early estimates of the transmission potential of emerging and re-emerging infections are increasingly used to inform public health authorities on the level of risk posed by outbreaks. Existing methods to estimate the reproduction number generally assume exponential growth in case incidence in the first few disease generations, before susceptible depletion sets in. In reality, outbreaks can display subexponential (i.e. polynomial) growth in the first few disease generations, owing to clustering in contact patterns, spatial effects, inhomogeneous mixing, reactive behaviour changes or other mechanisms. Here, we introduce the generalized growth model to characterize the early growth profile of outbreaks and estimate the effective reproduction number, with no need for explicit assumptions about the shape of epidemic growth. We demonstrate this phenomenological approach using analytical results and simulations from mechanistic models, and provide validation against a range of empirical disease datasets. Our results suggest that subexponential growth in the early phase of an epidemic is the rule rather the exception. Mechanistic simulations show that slight modifications to the classical susceptible–infectious–removed model result in subexponential growth, and in turn a rapid decline in the reproduction number within three to five disease generations. For empirical outbreaks, the generalized-growth model consistently outperforms the exponential model for a variety of directly and indirectly transmitted diseases datasets (pandemic influenza, measles, smallpox, bubonic plague, cholera, foot-and-mouth disease, HIV/AIDS and Ebola) with model estimates supporting subexponential growth dynamics. The rapid decline in effective reproduction number predicted by analytical results and observed in real and synthetic datasets within three to five disease generations contrasts with the expectation of invariant reproduction number in epidemics obeying exponential growth. The
Estimates of age, growth and mortality of spotted catfish, Arius ...
African Journals Online (AJOL)
Administrator
2011-11-02
Nov 2, 2011 ... the major by-catch species, and hence more attention should be paid to the dynamics of this stock. .... reflect the sea surface temperature of fishing ground (in this study, ... growth curve of spotted catfish is shown in Figure 4.
77 FR 21846 - Reserve Requirements of Depository Institutions: Reserves Simplification
2012-04-12
... Requirements of Depository Institutions: Reserves Simplification AGENCY: Board of Governors of the Federal Reserve System. ACTION: Final rule. SUMMARY: The Board is amending Regulation D, Reserve Requirements of Depository Institutions, to simplify the administration of reserve requirements. The final rule creates a...
Emissions estimates of carbon tetrachloride for 1992-2014 in China.
Bie, Pengju; Fang, Xuekun; Li, Zhifang; Wang, Ziyuan; Hu, Jianxin
2017-05-01
Discrepancies in emission estimates of carbon tetrachloride (CCl 4 , CTC), between bottom-up and top-down methods, have been shown since the 1990s at both the global and regional scale. This study estimates the emissions of China from 1992 to 2014 based on emission functions and aggregated activity information given reasonable uncertainties. The results show that emissions increase from 7.3 Gg/yr (5.6-9.1 Gg/yr at 95% confidential interval) to 14.0 (9.1-19.5) Gg/yr with a growth rate of 6.7 (1.9-11.4) %/yr during 1992-2002 and then decrease to a minimum of 4.3 (1.9-8.0) Gg/yr in 2011. More than 54% of the emissions during 1992-2009 are from the process agents sector. The estimates are comparable with those of other studies and those in this study based on observations during 2011-2014 using the interspecies correlation method. China's contribution to global emissions increases from 7.5% to 19.5% during 1992-2009, but the contribution is reduced to 9.9% and 8.0% in 2010 and 2011, respectively, indicating the effectiveness of compliance with the Montreal Protocol and its subsequent Amendments and Adjustments, whereby CTC emissions are phased-out. The results of this study are beneficial for narrowing the gap between bottom-up estimates and top-down emission calculations of CTC in China. Copyright © 2017 Elsevier Ltd. All rights reserved.
Re-evaluating neonatal-age models for ungulates: does model choice affect survival estimates?
Directory of Open Access Journals (Sweden)
Troy W Grovenburg
Full Text Available New-hoof growth is regarded as the most reliable metric for predicting age of newborn ungulates, but variation in estimated age among hoof-growth equations that have been developed may affect estimates of survival in staggered-entry models. We used known-age newborns to evaluate variation in age estimates among existing hoof-growth equations and to determine the consequences of that variation on survival estimates. During 2001-2009, we captured and radiocollared 174 newborn (≤24-hrs old ungulates: 76 white-tailed deer (Odocoileus virginianus in Minnesota and South Dakota, 61 mule deer (O. hemionus in California, and 37 pronghorn (Antilocapra americana in South Dakota. Estimated age of known-age newborns differed among hoof-growth models and varied by >15 days for white-tailed deer, >20 days for mule deer, and >10 days for pronghorn. Accuracy (i.e., the proportion of neonates assigned to the correct age in aging newborns using published equations ranged from 0.0% to 39.4% in white-tailed deer, 0.0% to 3.3% in mule deer, and was 0.0% for pronghorns. Results of survival modeling indicated that variability in estimates of age-at-capture affected short-term estimates of survival (i.e., 30 days for white-tailed deer and mule deer, and survival estimates over a longer time frame (i.e., 120 days for mule deer. Conversely, survival estimates for pronghorn were not affected by estimates of age. Our analyses indicate that modeling survival in daily intervals is too fine a temporal scale when age-at-capture is unknown given the potential inaccuracies among equations used to estimate age of neonates. Instead, weekly survival intervals are more appropriate because most models accurately predicted ages within 1 week of the known age. Variation among results of neonatal-age models on short- and long-term estimates of survival for known-age young emphasizes the importance of selecting an appropriate hoof-growth equation and appropriately defining intervals (i
A tree biomass and carbon estimation system
Emily B. Schultz; Thomas G. Matney; Donald L. Grebner
2013-01-01
Appropriate forest management decisions for the developing woody biofuel and carbon credit markets require inventory and growth-and-yield systems reporting component tree dry weight biomass estimates. We have developed an integrated growth-and-yield and biomass/carbon calculator. The objective was to provide Mississippiâs State inventory system with bioenergy economic...
Energy reserves and power plants in the USSR
Energy Technology Data Exchange (ETDEWEB)
Madaus, C
1971-12-01
Solid fuels are still of primary importance in the USSR. Coal reserves and production rates are outlined. Natural gas reserves are estimated to be about 70 x 10/sup 18/m/sup 3/, with operational fields having a capacity of about 12.1 x 10/sup 18/m/sup 3/. Detailed data concerning gas and hydrodynamic reserves, energy production statistics, and high-capacity condensation-turbines are tabulated. Extensive technical data is also provided concerning installed nuclear, thermal, and hydroelectric power plants. Solar energy remains in very early stages of development. In some areas, particularly the foothills of the Caucasus, Kirim, and Kamchatka, conditions are highly favorable for the development of geothermal power plants. A geothermal installation is planned for Kamchatka. It will have a capacity of 700-850 MW, and will be driven by thermal waters arising from the Awatschinskaja Sopka volcano. Four tidal power-plants were planned for construction by 1976. The first was completed in 1968, at the Barent Sea. One of these plants will have a capacity of 30-35 TWh/annum.
Probabilistic Mass Growth Uncertainties
Plumer, Eric; Elliott, Darren
2013-01-01
Mass has been widely used as a variable input parameter for Cost Estimating Relationships (CER) for space systems. As these space systems progress from early concept studies and drawing boards to the launch pad, their masses tend to grow substantially, hence adversely affecting a primary input to most modeling CERs. Modeling and predicting mass uncertainty, based on historical and analogous data, is therefore critical and is an integral part of modeling cost risk. This paper presents the results of a NASA on-going effort to publish mass growth datasheet for adjusting single-point Technical Baseline Estimates (TBE) of masses of space instruments as well as spacecraft, for both earth orbiting and deep space missions at various stages of a project's lifecycle. This paper will also discusses the long term strategy of NASA Headquarters in publishing similar results, using a variety of cost driving metrics, on an annual basis. This paper provides quantitative results that show decreasing mass growth uncertainties as mass estimate maturity increases. This paper's analysis is based on historical data obtained from the NASA Cost Analysis Data Requirements (CADRe) database.
Natural gas: reserves keep ahead of production
Energy Technology Data Exchange (ETDEWEB)
Hough, G V
1983-08-01
World production of natural gas in 1982 fell only 1.6% below 1981 levels, while proven recoverable reserves were up by 3.6% for a total of 3.279 quadrillion CF, which is 32.4% higher than had been estimated in 1978. Gas consumption, however, has experienced greater changes, with most of the industrialized countries (except for Japan) reporting declines in gas demand resulting from falling oil prices, reduced energy demand, and a slack world economy. Although gas seems to be holding its own in energy markets, further progress will not be easy to achieve.
Sonographic fetal weight estimation using femoral length: Honarvar Equation
International Nuclear Information System (INIS)
Firoozabadi, Raziah Dehghani; Ghasemi, N.; Firoozabadi, Mehdi Dehghani
2007-01-01
Fetal growth is the result of interactions between various factors and can be estimated by ultrasonic measurements. Fetal femur length is a scale for estimating the fetal weight in individual races because fetal growth patterns differ among different races. This was a prospective study involving 500 pregnant women at 36 weeks of gestational age. Real-time sonography was done to measure the femoral length and the weight of the fetus was estimated by the Honarvar 2 equation. The correlation between estimated fetal weight (EFW) and real weight was tested by Pearson correlation coefficient and relationships with the age and BMI of mother, the sex of the neonate and parity were tested by multiple regression. EFW by the Honarvar 2 equation correlated significantly with actual birthweight. Therefore, this equation is valid for fetal weight estimation. It also does not depend on the age and BMI of the mother, sex of the neonate, parity. Ethnicity potentially plays an important role in the fetal weight estimation. The Honarvar formula produced the best estimate of the actual birthweight for Iranian fetuses, and its use is recommended. (author)
Natalie R. Pinheiro; P. Charles Goebel; David M. Hix
2008-01-01
Using data collected in 1964 and 2006, we examined changes in the composition and structure of a second-growth and old-growth beech-maple forest of Crall Woods, located in Ashland County of north central Ohio. Over the 42 years, the old-growth forest (estimated to be at least 250 years old) experienced a significant shift in species composition as American beech,...
Assessment of renewable energy reserves in Taiwan
International Nuclear Information System (INIS)
Chen, Falin; Lu, Shyi-Min; Tseng, Kuo-Tung; Wang, Eric; Lee, Si-Chen
2010-01-01
Since Taiwan imports more than 99% of energy supply from foreign countries, energy security has always been the first priority for government to formulate energy policy. The development of renewable energy not only contributes to the independence of energy supply, but also achieves benefits of economic development and environmental protection. Based upon information available to public, the present paper reassesses reserves of various renewable energies in Taiwan. The assessment includes seven kinds of renewable energies, namely, solar energy, wind power, biomass energy, wave energy, tidal energy, geothermal energy and hydropower, which are all commercialized and matured in terms of current technologies. Other renewable energies, which have not proven as matured as the aforementioned ones, are only assessed preliminarily in this paper, such as second generation of biomass, deep geothermal energy, the Kuroshio power generation and ocean thermal energy conversion. According to the estimation of this paper, the reserve of wind energy, up to 29.9 kWh/d/p (i.e., kWh per day per person), is the largest one among seven kinds of renewable energies in Taiwan, followed by 24.27 kWh/d/p of solar energy, 4.55 kWh/d/p of biomass, 4.58 kWh/d/p of ocean energy, 0.67 kWh/d/p of geothermal energy and 16.79 kWh/d/p of hydropower. If regarding biomass as a primary energy, and assuming 40% being the average efficiency to convert primary energy into electricity, the total power of the seven kinds of renewable energy reserves is about 78.03 kWh/d/p, which is equal to 2.75 times of 28.35 kWh/d/p of national power generation in 2008. If the reserves of 54.93 kWh/d/p estimated from other four kinds of renewable energies that have not technically matured yet are also taken into account, it will result that the reserves of renewable energy in Taiwan can be quite abundant. Although the results of the assessment point out that Taiwan has abundant renewable energy resources, the four inherent
Flexible reserve markets for wind integration
Fernandez, Alisha R.
reserve market, identifying the operational constraints that inhibit a multi-purpose dam facility to meet the desired flexible energy demand. The second study transitions from the hydroelectric facility as the decision maker providing flex reserve services to the wind plant as the decision maker purchasing these services. In this second study, methods for allocating the costs of flex reserve services under different wind policy scenarios are explored that aggregate farms into different groupings to identify the least-cost strategy for balancing the costs of hourly day-ahead forecast errors. The least-cost strategy may be different for an individual wind plant and for the system operator, noting that the least-cost strategy is highly sensitive to cost allocation and aggregation schemes. The latter may also cause cross-subsidies in the cost for balancing wind forecast errors among the different wind farms. The third study builds from the second, with the objective to quantify the amount of flex reserves needed for balancing future forecast errors using a probabilistic approach (quantile regression) to estimating future forecast errors. The results further examine the usefulness of separate flexible markets PJM could use for balancing oversupply and undersupply events, similar to the regulation up and down markets used in Europe. These three studies provide the following results and insights to large-scale wind integration using actual PJM wind farm data that describe the markets and generators within PJM. • Chapter 2 provides an in-depth analysis of the valuable, yet highly-constrained, energy services multi-purpose hydroelectric facilities can provide, though the opportunity cost for providing these services can result in large deviations from the reservoir policies with minimal revenue gain in comparison to dedicating the whole of dam capacity to providing day-ahead, baseload generation. • Chapter 3 quantifies the system-wide efficiency gains and the distributive
Human Capital--Economic Growth Nexus in the Former Soviet Bloc
Osipian, Ararat L.
2007-01-01
This study analyses the role and impact of higher education on per capita economic growth in the Former Soviet Bloc. It attempts to estimate the significance of educational levels for initiating substantial economic growth that now takes place in these two countries. This study estimates a system of linear and log-linear equations that account for…
Zhang, Chen; Wang, Yuan; Song, Xiaowei; Kubota, Jumpei; He, Yanmin; Tojo, Junji; Zhu, Xiaodong
2017-12-31
This paper concentrates on a Chinese context and makes efforts to develop an integrated process to explicitly elucidate the relationship between economic growth and water pollution discharge-chemical oxygen demand (COD) discharge and ammonia nitrogen (NH 3 -N), using two unbalanced panel data sets covering the period separately from 1990 to 2014, and 2001 to 2014. In our present study, the panel unit root tests, cointegration tests, and Granger causality tests allowing for cross-sectional dependence, nonstationary, and heterogeneity are conducted to examine the causal effects of economic growth on COD/NH 3 -N discharge. Further, we simultaneously apply semi-parametric fixed effects estimation and parametric fixed effects estimation to investigate environmental Kuznets curve relationship for COD/NH 3 -N discharge. Our empirical results show a long-term bidirectional causality between economic growth and COD/NH 3 -N discharge in China. Within the Stochastic Impacts by Regression on Population, Affluence and Technology framework, we find evidence in support of an inverted U-shaped curved link between economic growth and COD/NH 3 -N discharge. To the best of our knowledge, there have not been any efforts made in investigating the nexus of economic growth and water pollution in such an integrated manner. Therefore, this study takes a fresh look on this topic. Copyright © 2017 Elsevier B.V. All rights reserved.
Emittance growth due to negative-mass instability above transition
International Nuclear Information System (INIS)
Ng, King-Yuen.
1994-08-01
Due to space-charge effect, there is a growth of bunch emittance across transition as a result of negative-mass instability. The models of growth at cutoff frequency and growth from high-frequency Schottky noise are reviewed. The difficulties of performing reliable simulations are discussed. An intuitive self-bunching model for estimating emittance growth is presented
2004 Workplace and Gender Relations Survey of Reserve Component Members: Tabulations of Responses
National Research Council Canada - National Science Library
2005-01-01
The 2004 Workplace and Gender Relations Survey of Reserve Component Members was designed to both estimate the level of sexual harassment and provide information on a variety of consequences of sexual harassment...
A framework for stochastic simulation of distribution practices for hotel reservations
Energy Technology Data Exchange (ETDEWEB)
Halkos, George E.; Tsilika, Kyriaki D. [Laboratory of Operations Research, Department of Economics, University of Thessaly, Korai 43, 38 333, Volos (Greece)
2015-03-10
The focus of this study is primarily on the Greek hotel industry. The objective is to design and develop a framework for stochastic simulation of reservation requests, reservation arrivals, cancellations and hotel occupancy with a planning horizon of a tourist season. In Greek hospitality industry there have been two competing policies for reservation planning process up to 2003: reservations coming directly from customers and a reservations management relying on tour operator(s). Recently the Internet along with other emerging technologies has offered the potential to disrupt enduring distribution arrangements. The focus of the study is on the choice of distribution intermediaries. We present an empirical model for the hotel reservation planning process that makes use of a symbolic simulation, Monte Carlo method, as, requests for reservations, cancellations, and arrival rates are all sources of uncertainty. We consider as a case study the problem of determining the optimal booking strategy for a medium size hotel in Skiathos Island, Greece. Probability distributions and parameters estimation result from the historical data available and by following suggestions made in the relevant literature. The results of this study may assist hotel managers define distribution strategies for hotel rooms and evaluate the performance of the reservations management system.
A framework for stochastic simulation of distribution practices for hotel reservations
International Nuclear Information System (INIS)
Halkos, George E.; Tsilika, Kyriaki D.
2015-01-01
The focus of this study is primarily on the Greek hotel industry. The objective is to design and develop a framework for stochastic simulation of reservation requests, reservation arrivals, cancellations and hotel occupancy with a planning horizon of a tourist season. In Greek hospitality industry there have been two competing policies for reservation planning process up to 2003: reservations coming directly from customers and a reservations management relying on tour operator(s). Recently the Internet along with other emerging technologies has offered the potential to disrupt enduring distribution arrangements. The focus of the study is on the choice of distribution intermediaries. We present an empirical model for the hotel reservation planning process that makes use of a symbolic simulation, Monte Carlo method, as, requests for reservations, cancellations, and arrival rates are all sources of uncertainty. We consider as a case study the problem of determining the optimal booking strategy for a medium size hotel in Skiathos Island, Greece. Probability distributions and parameters estimation result from the historical data available and by following suggestions made in the relevant literature. The results of this study may assist hotel managers define distribution strategies for hotel rooms and evaluate the performance of the reservations management system
Status of Shanxi Province's power and coal reserves
International Nuclear Information System (INIS)
Wu, D.C.; Shang, J.Y.
1995-01-01
An introduction to Shanxi's coal reserve, production, transportation utilization, electric power generation and transmission capacities is presented with the intention of providing outsiders a clear understanding of Shanxi's coal and power industries. Quantitative sketches of Shanxi's role in China's energy resource production and power generation are included. The province of Shanxi invites investors to visit Shanxi to gain first-hand knowledge. The authors have also taken the liberty of providing the high points of Shanxi's indigenous sceneries and local customs. They believe that in the future, Shanxi's coal based power development will be one of the principal drivers of China's economic growth
Implications of fossil fuel constraints on economic growth and global warming
International Nuclear Information System (INIS)
Nel, Willem P.; Cooper, Christopher J.
2009-01-01
Energy Security and Global Warming are analysed as 21st century sustainability threats. Best estimates of future energy availability are derived as an Energy Reference Case (ERC). An explicit economic growth model is used to interpret the impact of the ERC on economic growth. The model predicts a divergence from 20th century equilibrium conditions in economic growth and socio-economic welfare is only stabilised under optimistic assumptions that demands a paradigm shift in contemporary economic thought and focused attention from policy makers. Fossil fuel depletion also constrains the maximum extent of Global Warming. Carbon emissions from the ERC comply nominally with the B1 scenario, which is the lowest emissions case considered by the IPCC. The IPCC predicts a temperature response within acceptance limits of the Global Warming debate for the B1 scenario. The carbon feedback cycle, used in the IPCC models, is shown as invalid for low-emissions scenarios and an alternative carbon cycle reduces the temperature response for the ERC considerably compared to the IPCC predictions. Our analysis proposes that the extent of Global Warming may be acceptable and preferable compared to the socio-economic consequences of not exploiting fossil fuel reserves to their full technical potential
Schwindt, Adam R.; Winkelman, Dana L.
2016-01-01
Urban freshwater streams in arid climates are wastewater effluent dominated ecosystems particularly impacted by bioactive chemicals including steroid estrogens that disrupt vertebrate reproduction. However, more understanding of the population and ecological consequences of exposure to wastewater effluent is needed. We used empirically derived vital rate estimates from a mesocosm study to develop a stochastic stage-structured population model and evaluated the effect of 17α-ethinylestradiol (EE2), the estrogen in human contraceptive pills, on fathead minnow Pimephales promelas stochastic population growth rate. Tested EE2 concentrations ranged from 3.2 to 10.9 ng L−1 and produced stochastic population growth rates (λ S ) below 1 at the lowest concentration, indicating potential for population decline. Declines in λ S compared to controls were evident in treatments that were lethal to adult males despite statistically insignificant effects on egg production and juvenile recruitment. In fact, results indicated that λ S was most sensitive to the survival of juveniles and female egg production. More broadly, our results document that population model results may differ even when empirically derived estimates of vital rates are similar among experimental treatments, and demonstrate how population models integrate and project the effects of stressors throughout the life cycle. Thus, stochastic population models can more effectively evaluate the ecological consequences of experimentally derived vital rates.
Growth of Corophium volutator under laboratory conditions
Kater, B.J.; Jol, J.G.; Smit, M.G.D.
2008-01-01
Temperature-dependent growth is an important factor in the population model of Corophium volutator that was developed to translate responses in a 10-day acute bioassay to ecological consequences for the population. The growth rate, however, was estimated from old data, based on a Swedish population.
FASB statement 121 and other accounting issues affecting reserves reporting
Energy Technology Data Exchange (ETDEWEB)
Rowden, K R [Currie Coopers and Lybrand, Toronto, ON (Canada)
1996-03-01
The provisions required by FASB 121, and their impact on oil and gas properties, were explained. This included the impact of FASB statement 121, accounting for the impairment of long-lived assets and for assets to be disposed of on oil and gas properties. A two-tiered approach to recognition and measurement was described, as well as how reserve estimates are used for measurement of impairment. Reserve reports were considered to be the basis for financial statement disclosure. Procedures for reporting of finding costs and acquisition costs according to FASB 69 were described, and the Securities and Exchange Commission (SEC) reporting requirements were summarized.
FASB statement 121 and other accounting issues affecting reserves reporting
International Nuclear Information System (INIS)
Rowden, K.R.
1996-01-01
The provisions required by FASB 121, and their impact on oil and gas properties, were explained. This included the impact of FASB statement 121, accounting for the impairment of long-lived assets and for assets to be disposed of on oil and gas properties. A two-tiered approach to recognition and measurement was described, as well as how reserve estimates are used for measurement of impairment. Reserve reports were considered to be the basis for financial statement disclosure. Procedures for reporting of finding costs and acquisition costs according to FASB 69 were described, and the Securities and Exchange Commission (SEC) reporting requirements were summarized
A photon-driven micromotor can direct nerve fibre growth
Wu, Tao; Nieminen, Timo A.; Mohanty, Samarendra; Miotke, Jill; Meyer, Ronald L.; Rubinsztein-Dunlop, Halina; Berns, Michael W.
2012-01-01
Axonal path-finding is important in the development of the nervous system, nerve repair and nerve regeneration. The behaviour of the growth cone at the tip of the growing axon determines the direction of axonal growth and migration. We have developed an optical-based system to control the direction of growth of individual axons (nerve fibres) using laser-driven spinning birefringent spheres. One or two optical traps position birefringent beads adjacent to growth cones of cultured goldfish retinal ganglion cell axons. Circularly polarized light with angular momentum causes the trapped bead to spin. This creates a localized microfluidic flow generating an estimated 0.17 pN shear force against the growth cone that turns in response to the shear. The direction of axonal growth can be precisely manipulated by changing the rotation direction and position of this optically driven micromotor. A physical model estimating the shear force density on the axon is described.
Development of world coal reserves, their registration and their utilization
Energy Technology Data Exchange (ETDEWEB)
Bachmann, H
1979-10-01
This paper examines statistics on world coal production and world coal reserves with figures from 1860 to 1974 provided in tables and graphs. Eighty percent of the total world coal reserves (92% of world brown coal reserves) lie in the USA and USSR. The recent increase in total coal reserve estimates is due to exploration in western USA and in the USSR east of the Urals. Depth and thickness of the world's coal seams are shown in graphs and variations in coal quality are discussed. Problems associated with the anticipated substantial increase in coal production up to the year 2000 are considered. Encouraging higher coal production is the successful development of highly mechanized underground mining techniques and highly productive heavy surface mining equipment which allows excavation at increased depths. Surface mining is expected to make up 50% of total world mining operations in the near future. More complete deposit exploitation also contributes to higher coal production. Low international ship freight rates would facilitate future world coal trade. Obstacles are seen as: high, long term investments due to the fact that coal reserves lie far from populated and industrialized areas; opening new mines; transportation costs and infrastructure development.
A Sensorless Power Reserve Control Strategy for Two-Stage Grid-Connected PV Systems
DEFF Research Database (Denmark)
Sangwongwanich, Ariya; Yang, Yongheng; Blaabjerg, Frede
2017-01-01
Due to the still increasing penetration of grid-connected Photovoltaic (PV) systems, advanced active power control functionalities have been introduced in grid regulations. A power reserve control, where namely the active power from the PV panels is reserved during operation, is required for grid...... support. In this paper, a cost-effective solution to realize the power reserve for two-stage grid-connected PV systems is proposed. The proposed solution routinely employs a Maximum Power Point Tracking (MPPT) control to estimate the available PV power and a Constant Power Generation (CPG) control...... performed on a 3-kW two-stage single-phase grid-connected PV system, where the power reserve control is achieved upon demands....
Estimated natural uranium requirements to the year 2000
International Nuclear Information System (INIS)
Bennett, L.L.
1981-01-01
The future requirements for natural uranium are mainly dependent on the future growth of nuclear energy generation and the types of reactors operated to provide that energy. These topics were examined extensively by the International Nuclear Fuel Cycle Evaluation (INFCE). The resulting projections of nuclear power plant capacity and estimated requirements for natural uranium, other nuclear raw materials and fuel cycle services were presented in the final report of INFCE. The projections from INFCE are the most recent results published by an international body, and can therefore be taken as the most authoritative estimates presently available. The INFCE results have been reviewed in the light of latest trends in national nuclear power capacity figures, and a sub-set of the INFCE results are used as the basis for the demand estimates presented in this article. The principal criteria involved in the selection of this sub-set are the nuclear power growth estimates and the reactor and fuel cycle strategies. These criteria are discussed in the following sections
Minimum wage hikes and the wage growth of low-wage workers
Joanna K Swaffield
2012-01-01
This paper presents difference-in-differences estimates of the impact of the British minimum wage on the wage growth of low-wage employees. Estimates of the probability of low-wage employees receiving positive wage growth have been significantly increased by the minimum wage upratings or hikes. However, whether the actual wage growth of these workers has been significantly raised or not depends crucially on the magnitude of the minimum wage hike considered. Findings are consistent with employ...
Worker and Firm Heterogeneity in Wage Growth: An AKM approach
DEFF Research Database (Denmark)
Sørensen, Kenneth Lykke; Vejlin, Rune Majlund
This paper estimates a wage growth equation containing human capital variables known from the traditional Mincerian wage equation with year, worker and firm fixed effects included as well. The paper thus contributes further to the large empirical literature on unobserved heterogeneity following...... the work of Abowd, Kramarz, and Margolis (1999). Our main contribution is to extend the analysis from wage levels to wage growth. The specification enables us to estimate the individual specific and firm specific fixed effects and their degree of explanation on wage growth. The analysis is conducted using...... are estimated to explain four to ten per cent. We furthermore find a negative correlation between the worker and firm effects, as do nearly all authors examining wage level equations....
Effect of young maternal age and skeletal growth on placental growth and development.
Hayward, C E; Greenwood, S L; Sibley, C P; Baker, P N; Jones, R L
2011-12-01
Teenagers are susceptible to delivering small-for-gestational-age infants. Previous studies implicate continued skeletal growth as a contributory factor, and impaired placental development was the primary cause of fetal growth restriction in growing adolescent sheep. The aims of this study were to examine the impact of young maternal age and growth on placental development. Placentas were collected from 31 teenagers, of which 12 were growing and 17 non-growing based on knee height measurements. An adult control group (n = 12) was included. Placental weight and morphometric measurements of villous, syncytiotrophoblast, fibrin and vessel areas, as well as indices of proliferation and apoptosis, were analysed in relation to maternal growth and age. Growing teenagers had a higher birthweight:placental weight ratio than non-growing teenagers (p adult and teenage pregnancies. Maternal smoking, a potential confounding factor, did not exert a major influence on the placental parameters examined, except for a stimulatory effect on placental proliferation (p development, and is consistent with our recent observations that maternal growth was not detrimental to fetal growth. Copyright © 2011 Elsevier Ltd. All rights reserved.
Optimal Offering Strategies for Wind Power in Energy and Primary Reserve Markets
DEFF Research Database (Denmark)
Soares, Tiago; Pinson, Pierre; Jensen, Tue Vissing
2016-01-01
generation from the turbines. These offering strategies aim at maximizing expected revenues from both market floors using probabilistic forecasts for wind power generation, complemented with estimated regulation costs and penalties for failing to provide primary reserve. A set of numerical examples, as well......Wind power generation is to play an important role in supplying electric power demand, and will certainly impact the design of future energy and reserve markets. Operators of wind power plants will consequently develop adequate offering strategies, accounting for the market rules...... and the operational capabilities of the turbines, e.g., to participate in primary reserve markets. We consider two different offering strategies for joint participation of wind power in energy and primary reserve markets, based on the idea of proportional and constant splitting of potentially available power...
The Impact of External Debt on Economic Growth in Ghana: A ...
African Journals Online (AJOL)
A plethora of both cross-country and country-specific studies have been undertaken to estimate the impact of external debt on growth in developing countries. Their general findings though revealing need to be confirmed in Ghana. This paper estimates empirically the impact of external debt on economic growth in Ghana to ...
Houston, Natalie A.; Braun, Christopher L.
2004-01-01
This report describes the collection, analyses, and distribution of hydraulic-conductivity data obtained from slug tests completed in the alluvial aquifer underlying Air Force Plant 4 and Naval Air Station-Joint Reserve Base Carswell Field, Fort Worth, Texas, during October 2002 and August 2003 and summarizes previously available hydraulic-conductivity data. The U.S. Geological Survey, in cooperation with the U.S. Air Force, completed 30 slug tests in October 2002 and August 2003 to obtain estimates of horizontal hydraulic conductivity to use as initial values in a ground-water-flow model for the site. The tests were done by placing a polyvinyl-chloride slug of known volume beneath the water level in selected wells, removing the slug, and measuring the resulting water-level recovery over time. The water levels were measured with a pressure transducer and recorded with a data logger. Hydraulic-conductivity values were estimated from an analytical relation between the instantaneous displacement of water in a well bore and the resulting rate of head change. Although nearly two-thirds of the tested wells recovered 90 percent of their slug-induced head change in less than 2 minutes, 90-percent recovery times ranged from 3 seconds to 35 minutes. The estimates of hydraulic conductivity range from 0.2 to 200 feet per day. Eighty-three percent of the estimates are between 1 and 100 feet per day.
Assuring Software Cost Estimates: Is it an Oxymoron?
Hihn, Jarius; Tregre, Grant
2013-01-01
The software industry repeatedly observes cost growth of well over 100% even after decades of cost estimation research and well-known best practices, so "What's the problem?" In this paper we will provide an overview of the current state oj software cost estimation best practice. We then explore whether applying some of the methods used in software assurance might improve the quality of software cost estimates. This paper especially focuses on issues associated with model calibration, estimate review, and the development and documentation of estimates as part alan integrated plan.
Variance component and heritability estimates of early growth traits ...
African Journals Online (AJOL)
as selection criteria for meat production in sheep (Anon, 1970; Olson et ai., 1976;. Lasslo et ai., 1985; Badenhorst et ai., 1991). If these traits are to be included in a breeding programme, accurate estimates of breeding values will be needed to optimize selection programmes. This requires a knowledge of variance and co-.
Growth and yield predictions for upland oak stands. 10 years after initial thinning
Martin E. Dale; Martin E. Dale
1972-01-01
The purpose of this paper is to furnish part of the needed information, that is, quantitative estimates of growth and yield 10 years after initial thinning of upland oak stands. All estimates are computed from a system of equations. These predictions are presented here in tabular form for convenient visual inspection of growth and yield trends. The tables show growth...
Contraceptive failure rates: new estimates from the 1995 National Survey of Family Growth.
Fu, H; Darroch, J E; Haas, T; Ranjit, N
1999-01-01
Unintended pregnancy remains a major public health concern in the United States. Information on pregnancy rates among contraceptive users is needed to guide medical professionals' recommendations and individuals' choices of contraceptive methods. Data were taken from the 1995 National Survey of Family Growth (NSFG) and the 1994-1995 Abortion Patient Survey (APS). Hazards models were used to estimate method-specific contraceptive failure rates during the first six months and during the first year of contraceptive use for all U.S. women. In addition, rates were corrected to take into account the underreporting of induced abortion in the NSFG. Corrected 12-month failure rates were also estimated for subgroups of women by age, union status, poverty level, race or ethnicity, and religion. When contraceptive methods are ranked by effectiveness over the first 12 months of use (corrected for abortion underreporting), the implant and injectables have the lowest failure rates (2-3%), followed by the pill (8%), the diaphragm and the cervical cap (12%), the male condom (14%), periodic abstinence (21%), withdrawal (24%) and spermicides (26%). In general, failure rates are highest among cohabiting and other unmarried women, among those with an annual family income below 200% of the federal poverty level, among black and Hispanic women, among adolescents and among women in their 20s. For example, adolescent women who are not married but are cohabiting experience a failure rate of about 31% in the first year of contraceptive use, while the 12-month failure rate among married women aged 30 and older is only 7%. Black women have a contraceptive failure rate of about 19%, and this rate does not vary by family income; in contrast, overall 12-month rates are lower among Hispanic women (15%) and white women (10%), but vary by income, with poorer women having substantially greater failure rates than more affluent women. Levels of contraceptive failure vary widely by method, as well as by
Construction Cost Growth for New Department of Energy Nuclear Facilities
Energy Technology Data Exchange (ETDEWEB)
Kubic, Jr., William L. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
2014-05-25
Cost growth and construction delays are problems that plague many large construction projects including the construction of new Department of Energy (DOE) nuclear facilities. A study was conducted to evaluate cost growth of large DOE construction projects. The purpose of the study was to compile relevant data, consider the possible causes of cost growth, and recommend measures that could be used to avoid extreme cost growth in the future. Both large DOE and non-DOE construction projects were considered in this study. With the exception of Chemical and Metallurgical Research Building Replacement Project (CMRR) and the Mixed Oxide Fuel Fabrication Facility (MFFF), cost growth for DOE Nuclear facilities is comparable to the growth experienced in other mega construction projects. The largest increase in estimated cost was found to occur between early cost estimates and establishing the project baseline during detailed design. Once the project baseline was established, cost growth for DOE nuclear facilities was modest compared to non-DOE mega projects.
International Nuclear Information System (INIS)
Zhu, Y.; She, X.P.
2017-01-01
The main aim of this study was to analyze the mobilization of storage reserves during seed germination of Ammodendron bifolium by host plant-endophytic bacteria interaction and to determine the contribution of endophytic bacteria in plant establishment. The seeds were inoculated with three different endophytic bacteria from A. bifolium, Staphylococcus sp. AY3, Kocuria sp. AY9 and Bacillus sp. AG18, and they were germinated in the dark. Fresh weight changes and early seedling growth were assessed, and the content of storage compounds was quantified using biochemical assays in all germinated and non-germinated seeds. To understand the mechanism promoting seed germination, the activities of extracellular enzymes of bacterial isolates were also analyzed by the plate assay method. The results showed that treatment with endophytic bacteria accelerated seed germination; promoted further water absorption and radicle growth; and also promoted degradation of sucrose, protein and lipids during the germination process. At the same time, our results also showed that strain AG18 was able to produce protease and amylase, strain AY9 had only amylase activity, and strain AY3 had no extracellular enzyme activity. In summary, our current study showed that (i) endophytic bacteria improved seed germination and post-germination seedling growth of A. bifolium; (ii) inoculation with endophytic bacteria could promote storage reserve mobilization during or following germination; (iii) the degradation of protein, lipids and sucrose could provide essential energy for post-germination growth; and (iv) three bacterial isolates might have different action mechanisms on seed germination. (author)
Balderas Torres, Arturo; Lovett, Jonathan Cranidge
2012-01-01
Increasing use of woody plants for greenhouse gas mitigation has led to demand for rapid, cost-effective estimation of forest carbon stocks. Bole diameter is readily measured and basal area can be correlated to biomass and carbon through application of allometric equations. We explore different
77 FR 66361 - Reserve Requirements of Depository Institutions: Reserves Simplification
2012-11-05
... Requirements of Depository Institutions: Reserves Simplification AGENCY: Board of Governors of the Federal... (Reserve Requirements of Depository Institutions) published in the Federal Register on April 12, 2012. The... simplifications related to the administration of reserve requirements: 1. Create a common two-week maintenance...
Estimating exposure of terrestrial wildlife to contaminants
Energy Technology Data Exchange (ETDEWEB)
Sample, B.E.; Suter, G.W. II
1994-09-01
This report describes generalized models for the estimation of contaminant exposure experienced by wildlife on the Oak Ridge Reservation. The primary exposure pathway considered is oral ingestion, e.g. the consumption of contaminated food, water, or soil. Exposure through dermal absorption and inhalation are special cases and are not considered hereIN. Because wildlife mobile and generally consume diverse diets and because environmental contamination is not spatial homogeneous, factors to account for variation in diet, movement, and contaminant distribution have been incorporated into the models. To facilitate the use and application of the models, life history parameters necessary to estimate exposure are summarized for 15 common wildlife species. Finally, to display the application of the models, exposure estimates were calculated for four species using data from a source operable unit on the Oak Ridge Reservation.
Estimating exposure of terrestrial wildlife to contaminants
International Nuclear Information System (INIS)
Sample, B.E.; Suter, G.W. II.
1994-09-01
This report describes generalized models for the estimation of contaminant exposure experienced by wildlife on the Oak Ridge Reservation. The primary exposure pathway considered is oral ingestion, e.g. the consumption of contaminated food, water, or soil. Exposure through dermal absorption and inhalation are special cases and are not considered hereIN. Because wildlife mobile and generally consume diverse diets and because environmental contamination is not spatial homogeneous, factors to account for variation in diet, movement, and contaminant distribution have been incorporated into the models. To facilitate the use and application of the models, life history parameters necessary to estimate exposure are summarized for 15 common wildlife species. Finally, to display the application of the models, exposure estimates were calculated for four species using data from a source operable unit on the Oak Ridge Reservation
Foreign Exchange Reserves and the Reserve Bank’s Balance Sheet
Christian Vallence
2012-01-01
The Reserve Bank of Australia holds and manages the nation’s foreign exchange reserve assets in order to meet its policy objectives. While Australia’s foreign exchange reserves are relatively modest by international standards, they nonetheless constitute a sizeable portion of the Bank’s balance sheet, and variations in the Australian dollar value of these reserves are usually the most volatile component of the Bank’s profit and loss statement. This article discusses some of the key decisions ...
[Energy requirements in adolescents playing basketball in Russian Olympic reserve team].
Martinchik, A N; Baturin, A K; Petukhov, A B; Baeva, V S; Zemlianskaia, T A; Sokolov, A I; Peskova, E V; Tysiachnaia, E M
2003-01-01
The energy expenditure and requirements and dietary intake were studied in basketball players aged 14-16 years during 3 week-training period. The subjects of study were 14 boys and 18 girls as of the members of reserve of Russian Olympic basketball team. The dietary intake was estimated by dietary record of all food consumed within 24 hours last 7 days of training period. The energy expenditure was estimated by registration of time on different physical activity of team and multiplication on physical activity coefficient. The decrease of body mass and body mass index were observed in boys with height 195 cm and more to the end of training period. These tall boys did not consume enough food to satisfy the estimated energy requirement. It is estimated that energy need of tall basketball players is no less then 5000 kcal for boys and 3100 kcal for girls.
How Does Social Trust Affect Economic Growth?
DEFF Research Database (Denmark)
Bjørnskov, Christian
This paper connects two strands of the literature on social trust by estimating the effects of trust on growth through a set of potential transmission mechanisms directly. It does so by modelling the process using a three-stage least squares estimator on a sample of countries for which a full data...... set is available. The results indicate that trust affects schooling and the rule of law directly. These variables in turn affect the investment rate (schooling) and provide a direct effect (rule of law) on the growth rate. The paper closes with a short discussion of the relevance of the findings....
How Does Social Trust Affect Economic Growth?
DEFF Research Database (Denmark)
Bjørnskov, Christian
Social capital in the form of generalized trust has been shown to be a determinant of economic growth in a number of studies. Other studies have explored other consequences of trust, such as its effects on governance, corruption, education and investment. This paper connects the two strands...... of literature by estimating the effects of trust on growth through a set of potential transmission mechanisms directly. It does so by modelling the process using a three-stage least squares estimator on a sample of countries for which a full data set is available. The results indicate that trust affects...
A panel data investigation of real exchange rate misalignment and growth
Directory of Open Access Journals (Sweden)
Flávio Vilela Vieira
2012-09-01
Full Text Available The paper investigates the role of real exchange rate misalignment on long-run growth for a set of ninety countries using time series data from 1980 to 2004. We first estimate a panel data model (fixed and random effects for the real exchange rate in order to produce estimates of the equilibrium real exchange rate and this is then used to construct measures of real exchange rate misalignment. We provide an alternative set of estimates of RER misalignment using panel cointegration methods. The results for the two-step System GMM panel growth models indicate that the coefficients for real exchange rate misalignment are positive for different model specification and samples, which means that a more depreciated (appreciated real exchange rate helps (harms long-run growth. The estimated coefficients are higher for developing and emerging countries.
Intrauterine growth restriction
Directory of Open Access Journals (Sweden)
Bernardita Donoso Bernales
2012-07-01
Full Text Available It is estimated that the true prevalence of intrauterine growth restriction is 3-10% of all pregnancies, making this fetal condition one of the most frequent obstetric problems, together with premature labor and premature rupture of membranes. The article stresses the importance of early diagnosis because of the associated risks.
Belfort, Mandy B; Gillman, Matthew W; Buka, Stephen L; Casey, Patrick H; McCormick, Marie C
2013-12-01
To examine trade-offs between cognitive outcome and overweight/obesity in preterm-born infants at school age and young adulthood in relation to weight gain and linear growth during infancy. We studied 945 participants in the Infant Health and Development Program, an 8-center study of preterm (≤37 weeks gestational age), low birth weight (≤2500 g) infants from birth to age 18 years. Adjusting for maternal and child factors in logistic regression, we estimated the odds of overweight/obesity (body mass index [BMI] ≥85th percentile at age 8 or ≥25 kg/m(2) at age 18) and in separate models, low IQ (growth from term to 4 months was associated with lower odds of IQ growth soon after term was associated with better cognition, but also with a greater risk of overweight/obesity at age 8 years and 18 years. BMI gain over the entire 18 months after term was associated with later risk of overweight/obesity, with less evidence of a benefit for IQ. Copyright © 2013 Mosby, Inc. All rights reserved.
Marine reserves: fish life history and ecological traits matter.
Claudet, J; Osenberg, C W; Domenici, P; Badalamenti, F; Milazzo, M; Falcón, J M; Bertocci, I; Benedetti-Cecchi, L; García-Charton, J A; Goñi, R; Borg, J A; Forcada, A; De Lucia, G A; Perez-Ruzafa, A; Afonso, P; Brito, A; Guala, I; Le Diréach, L; Sanchez-Jerez, P; Somerfield, P J; Planes, S
2010-04-01
Marine reserves are assumed to protect a wide range of species from deleterious effects stemming from exploitation. However, some species, due to their ecological characteristics, may not respond positively to protection. Very little is known about the effects of life history and ecological traits (e.g., mobility, growth, and habitat) on responses of fish species to marine reserves. Using 40 data sets from 12 European marine reserves, we show that there is significant variation in the response of different species of fish to protection and that this heterogeneity can be explained, in part, by differences in their traits. Densities of targeted size-classes of commercial species were greater in protected than unprotected areas. This effect of protection increased as the maximum body size of the targeted species increased, and it was greater for species that were not obligate schoolers. However, contrary to previous theoretical findings, even mobile species with wide home ranges benefited from protection: the effect of protection was at least as strong for mobile species as it was for sedentary ones. Noncommercial bycatch and unexploited species rarely responded to protection, and when they did (in the case of unexploited bentho-pelagic species), they exhibited the opposite response: their densities were lower inside reserves. The use of marine reserves for marine conservation and fisheries management implies that they should ensure protection for a wide range of species with different life-history and ecological traits. Our results suggest this is not the case, and instead that effects vary with economic value, body size, habitat, depth range, and schooling behavior.
The need for official reserves in Latin America: Assessing the precautionary motive, 1995-2011
Directory of Open Access Journals (Sweden)
Moritz Cruz
2015-07-01
Full Text Available In this paper we estimate the demand for official reserves in Latin America during the period 1995-2011. We assume that the main concern of the monetary authorities to demand reserves is the fear of suffering external drains, and its associated output costs. In other words, we attempt to show that the so-called precautionary motive drives the demand for international reserves in the region. Our econometric results confirm that Latin American countries demand ever increasing amounts of foreign exchange to protect themselves against the likelihood of external drains.
Net Capital Flows, Macroeconomic Shocks and Reserve Assets. The Case of Argentina (1994-2013
Directory of Open Access Journals (Sweden)
Luis N. Lanteri
2014-06-01
Full Text Available International reserves have been used as a source of protection against the vulnerability of the balance of payments, or alternatively, as an attempt to keep a competitive real exchange rate and to promote exports. This paper explores the correlation between the net capital flows and reserves. Similarly, the impact of some macroeconomic shocks on that variable is assessed. Estimates are carried out through both, the VEC (Vector Error Correction models and quarterly data of the Argentine economy for the period 1994-2013. Results show a negative correlation between international reserves and net capital flows (reserve accumulation through current account surpluses. At the same time, the expansionary fiscal policies and the continuing and widespread price increases would adversely affect the reserves.
Age and growth of Sandelia bainsii Castelnau (Pisces: Anabantidae ...
African Journals Online (AJOL)
Otoliths and scales were used for age and growth determination of Sandelia bainsii. There was a linear relationship between fish length and both scale and otolith radii. Growth rings were deposited annually in spring. Otoliths provide a more reliable estimate of age and growth than scales. Males grow faster, reach a larger ...
Replacing reserve requirements
Edward J. Stevens
1993-01-01
An examination of the fading significance of the Federal Reserve System's reserve requirements and the recent flowering of required clearing balances, a rapidly growing feature of Reserve Bank operations.
Modelling asymmetric growth in crowded plant communities
DEFF Research Database (Denmark)
Damgaard, Christian
2010-01-01
A class of models that may be used to quantify the effect of size-asymmetric competition in crowded plant communities by estimating a community specific degree of size-asymmetric growth for each species in the community is suggested. The model consists of two parts: an individual size......-asymmetric growth part, where growth is assumed to be proportional to a power function of the size of the individual, and a term that reduces the relative growth rate as a decreasing function of the individual plant size and the competitive interactions from other plants in the neighbourhood....
Optimal offering and allocation policies for wind power in energy and reserve markets
DEFF Research Database (Denmark)
Soares, Tiago; Jensen, Tue Vissing; Mazzi, Nicolo
2017-01-01
Cormick relaxation and piecewise linear decision rules are adapted and tested aiming to maximize the expected revenue for participating in both energy and reserve markets, while accounting for estimated balancing costs for failing to provide energy and reserve. A set of numerical examples, as well as a case study......Proliferation of wind power generation is increasingly making this power source an important asset in designs of energy and reserve markets. Intuitively, wind power producers will require the development of new offering strategies that maximize the expected profit in both energy and reserve markets...... of better forecast information from the different day-ahead and balancing stages, allowing different shares of energy and reserve in both stages. Under these assumptions, different mathematical methods able to deal with the uncertain nature of wind power generation, namely, stochastic programming, with Mc...
Revisiting a model of ontogenetic growth: estimating model parameters from theory and data.
Moses, Melanie E; Hou, Chen; Woodruff, William H; West, Geoffrey B; Nekola, Jeffery C; Zuo, Wenyun; Brown, James H
2008-05-01
The ontogenetic growth model (OGM) of West et al. provides a general description of how metabolic energy is allocated between production of new biomass and maintenance of existing biomass during ontogeny. Here, we reexamine the OGM, make some minor modifications and corrections, and further evaluate its ability to account for empirical variation on rates of metabolism and biomass in vertebrates both during ontogeny and across species of varying adult body size. We show that the updated version of the model is internally consistent and is consistent with other predictions of metabolic scaling theory and empirical data. The OGM predicts not only the near universal sigmoidal form of growth curves but also the M(1/4) scaling of the characteristic times of ontogenetic stages in addition to the curvilinear decline in growth efficiency described by Brody. Additionally, the OGM relates the M(3/4) scaling across adults of different species to the scaling of metabolic rate across ontogeny within species. In providing a simple, quantitative description of how energy is allocated to growth, the OGM calls attention to unexplained variation, unanswered questions, and opportunities for future research.
Wang, Quanchao; Yu, Yang; Li, Fuhua; Zhang, Xiaojun; Xiang, Jianhai
2017-09-01
Genomic selection (GS) can be used to accelerate genetic improvement by shortening the selection interval. The successful application of GS depends largely on the accuracy of the prediction of genomic estimated breeding value (GEBV). This study is a first attempt to understand the practicality of GS in Litopenaeus vannamei and aims to evaluate models for GS on growth traits. The performance of GS models in L. vannamei was evaluated in a population consisting of 205 individuals, which were genotyped for 6 359 single nucleotide polymorphism (SNP) markers by specific length amplified fragment sequencing (SLAF-seq) and phenotyped for body length and body weight. Three GS models (RR-BLUP, BayesA, and Bayesian LASSO) were used to obtain the GEBV, and their predictive ability was assessed by the reliability of the GEBV and the bias of the predicted phenotypes. The mean reliability of the GEBVs for body length and body weight predicted by the different models was 0.296 and 0.411, respectively. For each trait, the performances of the three models were very similar to each other with respect to predictability. The regression coefficients estimated by the three models were close to one, suggesting near to zero bias for the predictions. Therefore, when GS was applied in a L. vannamei population for the studied scenarios, all three models appeared practicable. Further analyses suggested that improved estimation of the genomic prediction could be realized by increasing the size of the training population as well as the density of SNPs.
New diagnostic tests of GH reserve.
Martul, P; Pineda, J; Pombo, M; Peñalva, A; Bokser, L; Dieguez, C
1993-01-01
Pharmacological tests are essential for the diagnosis of growth hormone (GH) insufficiency. Obesity is a pathological state associated with blunted GH response to all the classical stimuli tested. In the present study, three new pharmacological stimuli for GH reserve were evaluated in three groups of subjects: Normal, GH-insufficient and normal growing obese children. Dexamethasone provokes a clear GH-response in normal children, whereas the response in the other 2 groups of patients is significantly diminished. Galanin-induced GH-secretion is significantly higher in normal than in obese children. GHRP-6 causes a potent GH release in normal children, higher than in GH-insufficiency or obesity. The overlap shown between GH-insufficient patients and normal children reduces the usefulness of the tests. Similar to the classical stimuli, the response to these new tests is also decreased in obesity.
Cladoceran birth and death rates estimates
Gabriel, Wilfried; Taylor, B. E.; Kirsch-Prokosch, Susanne
1987-01-01
I. Birth and death rates of natural cladoceran populations cannot be measured directly. Estimates of these population parameters must be calculated using methods that make assumptions about the form of population growth. These methods generally assume that the population has a stable age distribution. 2. To assess the effect of variable age distributions, we tested six egg ratio methods for estimating birth and death rates with data from thirty-seven laboratory populations of Daphnia puli...
Mark D. Nelson; John Vissage
2007-01-01
The Forest Inventory and Analysis (FIA) program produces area estimates of forest land use within three subcategories: timberland, reserved forest land, and other forest land. Mapping these subcategories of forest land requires the ability to spatially distinguish productive from unproductive land, and reserved from nonreserved land. FIA field data were spatially...
Do otolith increments allow correct inferences about age and growth of coral reef fishes?
Booth, D. J.
2014-03-01
Otolith increment structure is widely used to estimate age and growth of marine fishes. Here, I test the accuracy of the long-term otolith increment analysis of the lemon damselfish Pomacentrus moluccensis to describe age and growth characteristics. I compare the number of putative annual otolith increments (as a proxy for actual age) and widths of these increments (as proxies for somatic growth) with actual tagged fish-length data, based on a 6-year dataset, the longest time course for a coral reef fish. Estimated age from otoliths corresponded closely with actual age in all cases, confirming annual increment formation. However, otolith increment widths were poor proxies for actual growth in length [linear regression r 2 = 0.44-0.90, n = 6 fish] and were clearly of limited value in estimating annual growth. Up to 60 % of the annual growth variation was missed using otolith increments, suggesting the long-term back calculations of otolith growth characteristics of reef fish populations should be interpreted with caution.
Evaluation of Aguas Dulces Black sands reserves, Rocha, Uruguay
International Nuclear Information System (INIS)
Ferrando, L.; Bossi, J.; Maldonado, S.; Schipilov; Campal, N.
2003-01-01
Black sands data in Aguas Dulces (Rocha) studied by ANCAP during 60 were reanalyzed with geological criterion in order to redefine the prefactibility of economic explotation with the present infrastructure and world market conditions.The sand deposits is limited between a high slope palaeocost and the ocean, with medium depth of 10m and 2% of useful minerals:ilmenite, rutile, monazite and zircon.Mineral reserves expressed in thousands of tons are of 3 kinds:proved (3.600), probable (5.500) and possible (16.000=.Demonstrated reserves (proved + probable) allow to estimate a value of U$S 650 million, taking in account year 2000 prices. A factory to process about 7 millions ton of raw sand needs an investment of U$S 13 million and will produce a sale of U$S 8 million per year
Financial repression, money growth, and seignorage: The Polish experience
Aarle, B. van; Budina, N.
1997-01-01
Financial Repression, Money Growth and Seignorage: The Polish Experience. — A small analytical framework is developed to analyze the relation between reserve requirements, base money growth and seignorage revenues. From the analysis, the authors can derive of steady-state seignorage revenues as a
Monetary Policy Signaling from the Administration to the Federal Reserve.
Havrilesky, Thomas
1988-01-01
This paper develops an index of monetary policy signals from the Administration to the Federal Reserve based on articles which appeared in the Wall Street Journal in which Administration off icials express a desire for easier or tighter monetary policy. In reg ressions, the index has a significant effect on the money supply. In reaction functions, the index responds to variables which measure the state of the economy. Money growth does not respond to the same stat e-of-the-economy measures bu...
Hydrobiological investigations of Kytalyk Wildlife Reserve polygonal ponds (North-Eastern Yakutia)
Nigamatzyanova, G.; Frolova, L.; Pestryakova, L.
2018-01-01
In the following article there are introduced the first researching results of 27 water bodies of polygonal tundra in Kytalyk Wildlife Reserve in the summer 2011. The evaluation of physic-hydrochemical indexes of water bodies is given. The basic structure-forming characteristics of zooplankton communities are analyzed. The ecological state of the lakes is estimated.
Estimating regional centile curves from mixed data sources and countries
Buuren, S. van; Hayes, D.J.; Stasinopoulos, D.M.; Rigby, R.A.; Kuile, F.O. ter; Terlouw, D.J.
2009-01-01
Regional or national growth distributions can provide vital information on the health status of populations. In most resource poor countries, however, the required anthropometric data from purpose-designed growth surveys are not readily available. We propose a practical method for estimating
Modeling growth performances, survival, and feed efficiency of four ...
African Journals Online (AJOL)
Evolution of growth rate with age was similar in the four groups, but significant differences of growth curve parameters were found among breeds and/or sexes. Estimated hatch weight was lower in C hens and higher in FT hens. Initial specific growth rates and asymptotic body weight were higher in males for all breeds.
12 CFR Appendix M1 to Part 226 - Generic Repayment Estimates
2010-01-01
... 12 Banks and Banking 3 2010-01-01 2010-01-01 false Generic Repayment Estimates M1 Appendix M1 to Part 226 Banks and Banking FEDERAL RESERVE SYSTEM (CONTINUED) BOARD OF GOVERNORS OF THE FEDERAL RESERVE... rounded down to the nearest whole year if the estimate contains a fractional year less than 0.5, and...
Accounting for uncertainty in marine reserve design.
Halpern, Benjamin S; Regan, Helen M; Possingham, Hugh P; McCarthy, Michael A
2006-01-01
Ecosystems and the species and communities within them are highly complex systems that defy predictions with any degree of certainty. Managing and conserving these systems in the face of uncertainty remains a daunting challenge, particularly with respect to developing networks of marine reserves. Here we review several modelling frameworks that explicitly acknowledge and incorporate uncertainty, and then use these methods to evaluate reserve spacing rules given increasing levels of uncertainty about larval dispersal distances. Our approach finds similar spacing rules as have been proposed elsewhere - roughly 20-200 km - but highlights several advantages provided by uncertainty modelling over more traditional approaches to developing these estimates. In particular, we argue that uncertainty modelling can allow for (1) an evaluation of the risk associated with any decision based on the assumed uncertainty; (2) a method for quantifying the costs and benefits of reducing uncertainty; and (3) a useful tool for communicating to stakeholders the challenges in managing highly uncertain systems. We also argue that incorporating rather than avoiding uncertainty will increase the chances of successfully achieving conservation and management goals.
Nannini, Matteo; De Marchi, Lucia; Lombardi, Chiara; Ragazzola, Federica
2015-12-01
Coralline algae are calcareous algae able to build biogenic structures, thus playing a key-role as marine biodiversity promoters and calcium carbonate producers. The aim was to estimate the growth of Ellisolandia elongata under thermal stress. E. elongata were cultured for 2, 4 and 6 months under "natural" temperature (Tc) and increased temperature (Ti = Tc + 3 °C). In order to determine a possible culturing effect, growth in the field was also measured. For the first time, Alizarin Red S dye was used in high energy shallow water environments. Thallus linear extension was higher in the cultured specimens (Tc and Ti) compared to the field specimens. The carbonate mass in the field was higher than in Ti and Tc after 2, 4 months but decreased after 6 months. Partly unknown in situ environmental factors could have affected growth and calcification rates in the field while thermal adaptation could explain growth rates in the culturing experiment. Copyright © 2015 Elsevier Ltd. All rights reserved.
Nev, Olga A; Nev, Oleg A; van den Berg, Hugo A
2017-09-21
Intracellular reserves are a conspicuous feature of many bacteria; such internal stores are often present in the form of inclusions in which polymeric storage compounds are accumulated. Such reserves tend to increase in times of plenty and be used up in times of scarcity. Mathematical models that describe the dynamical nature of reserve build-up and use are known as "cell quota," "dynamic energy/nutrient budget," or "variable-internal-stores" models. Here we present a stoichiometrically consistent macro-chemical model that accounts for variable stores as well as adaptive allocation of building blocks to various types of catalytic machinery. The model posits feedback loops linking expression of assimilatory machinery to reserve density. The precise form of the "regulatory law" at the heart of such a loop expresses how the cell manages internal stores. We demonstrate how this "regulatory law" can be recovered from experimental data using several empirical data sets. We find that stores should be expected to be negligibly small in stable growth-sustaining environments, but prominent in environments characterised by marked fluctuations on time scales commensurate with the inherent dynamic time scale of the organismal system. Copyright © 2017 Elsevier Ltd. All rights reserved.
Estimation of collective instabilities in RHIC
International Nuclear Information System (INIS)
MacKay, W.W.; Blaskiewicz, M.; Deng, D.; Mane, V.; Peggs, S.; Ratti, A.; Rose, J.; Shea, T.J.; Wei, J.
1995-01-01
The authors have estimated the broadband impedance in RHIC to be |Z/n| +79 ions at transition with an estimated 10% growth in emittance for Z/n = 1.5 Ω. They summarize the sources of broad and narrow band impedances in RHIC and investigate the multibunch instability limits throughout the machine cycle. The largest contribution to the broadband impedance comes from the abort and injection kickers. Since RHIC is designed to accelerate fully stripped ions from H + up to Au +79 they give results for both protons and gold ions; other ions should give results somewhere between these two extremes. All ion species are expected to be stable during storage. At lower energies damping systems and chromaticity corrections will limit any growth to acceptable levels during the short time it takes to inject and accelerate the beams
Forest evaporation models: Relationships between stand growth and evaporation
CSIR Research Space (South Africa)
Le Maitre, David C
1997-06-01
Full Text Available The relationships between forest stand structure, growth and evaporation were analysed to determine whether forest evaporation can be estimated from stand growth data. This approach permits rapid assessment of the potential impacts of afforestation...
Larval export from marine reserves and the recruitment benefit for fish and fisheries
Harrison, Hugo B.; Williamson, David H.; Evans, Richard D.; Almany, Glenn R.; Thorrold, Simon R.; Russ, Garry Ronald; Feldheim, Kevin Andrew; Van Herwerden, Lynne Van; Planes, Serge; Srinivasan, Maya; Berumen, Michael L.; Jones, Geoffrey P.
2012-01-01
Marine reserves, areas closed to all forms of fishing, continue to be advocated and implemented to supplement fisheries and conserve populations [1-4]. However, although the reproductive potential of important fishery species can dramatically increase inside reserves [5-8], the extent to which larval offspring are exported and the relative contribution of reserves to recruitment in fished and protected populations are unknown [4, 9-11]. Using genetic parentage analyses, we resolve patterns of larval dispersal for two species of exploited coral reef fish within a network of marine reserves on the Great Barrier Reef. In a 1,000 km 2 study area, populations resident in three reserves exported 83% (coral trout, Plectropomus maculatus) and 55% (stripey snapper, Lutjanus carponotatus) of assigned offspring to fished reefs, with the remainder having recruited to natal reserves or other reserves in the region. We estimate that reserves, which account for just 28% of the local reef area, produced approximately half of all juvenile recruitment to both reserve and fished reefs within 30 km. Our results provide compelling evidence that adequately protected reserve networks can make a significant contribution to the replenishment of populations on both reserve and fished reefs at a scale that benefits local stakeholders. © 2012 Elsevier Ltd.
Larval export from marine reserves and the recruitment benefit for fish and fisheries
Harrison, Hugo B.
2012-06-01
Marine reserves, areas closed to all forms of fishing, continue to be advocated and implemented to supplement fisheries and conserve populations [1-4]. However, although the reproductive potential of important fishery species can dramatically increase inside reserves [5-8], the extent to which larval offspring are exported and the relative contribution of reserves to recruitment in fished and protected populations are unknown [4, 9-11]. Using genetic parentage analyses, we resolve patterns of larval dispersal for two species of exploited coral reef fish within a network of marine reserves on the Great Barrier Reef. In a 1,000 km 2 study area, populations resident in three reserves exported 83% (coral trout, Plectropomus maculatus) and 55% (stripey snapper, Lutjanus carponotatus) of assigned offspring to fished reefs, with the remainder having recruited to natal reserves or other reserves in the region. We estimate that reserves, which account for just 28% of the local reef area, produced approximately half of all juvenile recruitment to both reserve and fished reefs within 30 km. Our results provide compelling evidence that adequately protected reserve networks can make a significant contribution to the replenishment of populations on both reserve and fished reefs at a scale that benefits local stakeholders. © 2012 Elsevier Ltd.
Seasonal carbon storage and growth in Mediterranean tree seedlings under different water conditions.
Sanz-Pérez, Virginia; Castro-Díez, Pilar; Joffre, Richard
2009-09-01
In all Mediterranean-type ecosystems, evergreen and deciduous trees differing in wood anatomy, growth pattern and leaf habit coexist, suggesting distinct adaptative responses to environmental constraints. This study examined the effects of summer water stress on carbon (C) storage and growth in seedlings of three coexisting Mediterranean trees that differed in phenology and wood anatomy characteristics: Quercus ilex subsp. ballota (Desf.) Samp., Quercus faginea Lam. and Pinus halepensis L. Seedlings were subjected to two levels of watering during two consecutive summers and achieved a minimum of -0.5 and -2.5 MPa of predawn water potential in the control and water stress treatment, respectively. Both Quercus species concentrated their growth in the early growing season, demanding higher C in early spring but replenishing C-stores in autumn. These species allocated more biomass to roots, having larger belowground starch and lipid reserves. Quercus species differed in seasonal storage dynamics from P. halepensis. This species allocated most of its C to aboveground growth, which occurred gradually during the growing season, leading to fewer C-reserves. Soluble sugar and starch concentrations sharply declined in August in P. halepensis, probably because reserves support respiration demands as this species closed stomata earlier under water stress. Drought reduced growth of the three species, mainly in Q. faginea and P. halepensis, but not C-reserves, suggesting that growth under water stress conditions is not limited by C-availability.
DEFF Research Database (Denmark)
Sommer, Helle Mølgaard; Holst, Helle; Spliid, Henrik
1995-01-01
Three identical microbiological experiments were carried out and analysed in order to examine the variability of the parameter estimates. The microbiological system consisted of a substrate (toluene) and a biomass (pure culture) mixed together in an aquifer medium. The degradation of the substrate...... and the growth of the biomass are described by the Monod model consisting of two nonlinear coupled first-order differential equations. The objective of this study was to estimate the kinetic parameters in the Monod model and to test whether the parameters from the three identical experiments have the same values....... Estimation of the parameters was obtained using an iterative maximum likelihood method and the test used was an approximative likelihood ratio test. The test showed that the three sets of parameters were identical only on a 4% alpha level....
Linking genes to microbial growth kinetics: an integrated biochemical systems engineering approach.
Koutinas, Michalis; Kiparissides, Alexandros; Silva-Rocha, Rafael; Lam, Ming-Chi; Martins Dos Santos, Vitor A P; de Lorenzo, Victor; Pistikopoulos, Efstratios N; Mantalaris, Athanasios
2011-07-01
The majority of models describing the kinetic properties of a microorganism for a given substrate are unstructured and empirical. They are formulated in this manner so that the complex mechanism of cell growth is simplified. Herein, a novel approach for modelling microbial growth kinetics is proposed, linking biomass growth and substrate consumption rates to the gene regulatory programmes that control these processes. A dynamic model of the TOL (pWW0) plasmid of Pseudomonas putida mt-2 has been developed, describing the molecular interactions that lead to the transcription of the upper and meta operons, known to produce the enzymes for the oxidative catabolism of m-xylene. The genetic circuit model was combined with a growth kinetic model decoupling biomass growth and substrate consumption rates, which are expressed as independent functions of the rate-limiting enzymes produced by the operons. Estimation of model parameters and validation of the model's predictive capability were successfully performed in batch cultures of mt-2 fed with different concentrations of m-xylene, as confirmed by relative mRNA concentration measurements of the promoters encoded in TOL. The growth formation and substrate utilisation patterns could not be accurately described by traditional Monod-type models for a wide range of conditions, demonstrating the critical importance of gene regulation for the development of advanced models closely predicting complex bioprocesses. In contrast, the proposed strategy, which utilises quantitative information pertaining to upstream molecular events that control the production of rate-limiting enzymes, predicts the catabolism of a substrate and biomass formation and could be of central importance for the design of optimal bioprocesses. Copyright © 2011 Elsevier Inc. All rights reserved.
Sociopolitical Instability and Economic Growth Empirical Evidence from Sri Lanka
Changsheng Xu; Santhirasegaram Selvarathinam; Wen X. Li
2007-01-01
Sociopolitical instability severely affects economic growth in short and long run. This study analyzes that sociopolitical instability measured by proxy measure; annual growth rate of tourist arrivals in Sri Lanka during 1960-2005 adversely affects economic growth. Our empirical findings based on ordinary lease square econometric estimation, show that sociopolitical instability negatively and significantly affect economic growth. Reduction of economic growth rate (-0.032) due to the sociopoli...
Energy Technology Data Exchange (ETDEWEB)
Zachmann, M
1982-03-01
The methods of estimation of bone maturation (Greulich and Pyle, Tanner et al.) and the possibilities for the calculation of future adult heigth (Bayley and Pinneau, Roche et al., Tanner et al.) are briefly described and their advantages and disadvantages in normal children and in children with growth disorders are discussed. In normal children, all methods provide valuable results, but there are small differences of precision depending on whether the pubertal development is early, average, or late. In pathological conditions, however, as e.g. in precocious puberty or in girls with Turner syndrome, the methods of Roche et al. and of Tanner et al. may overestimate adult height considerably, while that of Bayley and Pinneau remains reasonably accurate. A computerized system, which facilitates the complicated and time-consuming calculations is briefly presented.
DEFF Research Database (Denmark)
Nielsen, Rune; Munk, Peter
2004-01-01
and May 2001), and larval/juvenile growth history from each of the sampling sequences was outlined. Growth rate was estimated by fitting a Laird-Gompertz equation to lengths-at-age, and we found the mean specific growth rate in length at age 20 d was 3.2% d(-1), declining to 1.9% d(-1) at an age of 90 d....... Otolith radius and larval standard length were highly correlated, and otolith growth was used as a measure of larval somatic growth. The larvae were divided into 3 groups dependent on their hatch-date, and for each hatch group, the same period of past growth was compared between fish sampled in April...... and May. A 2-way repeated-measurement ANOVA revealed a significant higher past growth of fish sampled in May in 2 of the 3 hatch-groups, implying a higher mortality of the slow growing larvae. Additionally, otolith size at age differed significantly between the April and May sampling of the oldest larvae...
Parameter Estimation of Nonlinear Models in Forestry.
Fekedulegn, Desta; Mac Siúrtáin, Máirtín Pádraig; Colbert, Jim J.
1999-01-01
Partial derivatives of the negative exponential, monomolecular, Mitcherlich, Gompertz, logistic, Chapman-Richards, von Bertalanffy, Weibull and the Richard’s nonlinear growth models are presented. The application of these partial derivatives in estimating the model parameters is illustrated. The parameters are estimated using the Marquardt iterative method of nonlinear regression relating top height to age of Norway spruce (Picea abies L.) from the Bowmont Norway Spruce Thinnin...
Directory of Open Access Journals (Sweden)
Christopher R. Keyes
2014-02-01
Full Text Available Restoration of second-growth riparian stands has become an important issue for managers of redwood (Sequoia sempervirens [D. Don] Endl. forest reserves. Identifying differences between old-growth and second-growth forest vegetation is a necessary step in evaluating restoration needs and targets. The objective of this study was to characterize and contrast vegetation structure and composition in old-growth and unmanaged second-growth riparian forests in adjacent, geomorphologically similar watersheds at Redwood National Park. In the old-growth, redwood was the dominant overstory species in terms of stem density, basal area, and importance values. Second-growth was dominated by red alder (Alnus rubra Bong., Douglas-fir (Pseudotsuga menziesii [Mirbel] Franco, and redwood. Understory species were similar in both forests, with several key differences: Oxalis oregana Nutt. and Trillium ovatum Pursh had greater importance values in the old-growth, and Vaccinium parvifolium Sm., Dryopteris spp. and sedges Carex spp. had greater importance values in the second-growth. Notable differences in structure and composition suggest that restoration practices such as thinning could expedite the acquisition of old-growth characteristics in second-growth riparian forests.
Bar-El Dadon, Shimrit; Shahar, Ron; Katalan, Vered; Monsonego-Ornan, Efrat; Reifen, Ram
2011-09-01
Skeletal abnormalities are one of the hallmarks of growth delay during gestation. The aim of this study was to determine changes induced by leptin in skeletal growth and development in a rat model of intrauterine growth retardation (IUGR) and to elucidate the possible underlying mechanisms. Intrauterine growth retardation was induced prepartum and the effects of leptin to mothers prenatally or to offspring postnatally were studied. Radii were harvested and tested mechanically and structurally. Tibias were evaluated for growth-plate morphometry. On day 40 postpartum, total bone length and mineral density and tibial growth-plate width and numbers of cells within its zones of offspring treated with leptin were significantly greater than in the control group. Postnatal leptin administration in an IUGR model improves the structural properties and elongation rate of bone. These findings could pave the way to preventing some phenotypic presentations of IUGR. Copyright © 2011 Elsevier Inc. All rights reserved.
Basak, Suradeep; Guha, Proshanta
2015-12-23
The current study aimed at characterizing the chemical components of betel leaf (Piper betle L. var. Tamluk Mitha) essential oil (BLEO) and modelling its effect on growth of Penicillium expansum on semi-synthetic medium. Gas chromatography-mass spectrophotometry (GC-MS) analysis of BLEO revealed the presence of different bioactive phenolic compounds in significant amounts. Among 46 different components identified, chavibetol (22.0%), estragole (15.8%), β-cubebene (13.6%), chavicol (11.8%), and caryophyllene (11.3%) were found to be the major compounds of BLEO. A disc diffusion and disc volatilization method were used to evaluate antifungal activity of the oil against a selected food spoilage mould. The logistic model was used to study the kinetics of spore germination. Prediction and validation of antifungal effect of BLEO was performed on semi-synthetic medium (apple juice agar) using predictive microbiological tools. The Baranyi and Roberts model was used to estimate maximum growth rate (μmax in mm/day) and apparent lag time (λ in days) of the mould. Secondary modelling was performed using a re-parameterized Monod-type equation based on cardinal values to study the effect of different BLEO concentration on estimated growth parameters. Emax (minimum concentration of oil at which mould growth was inhibited) and MIC (minimum inhibitory concentration of BLEO at which lag time is infinite) value of BLEO against P. expansum was estimated to be 0.56 and 0.74 μl/ml, respectively, which was found to be similar on potato dextrose agar (PDA) as well as apple juice agar (AJA) medium. The correlation between estimated growth parameters of the mould on both the media was obtained with satisfactory statistical indices (R(2) and RMSE). This study revealed inhibitory efficacy of BLEO on spore germination, mycelial growth and apparent lag time of P. expansum in a dose-dependent manner. Hence, BLEO has potential to be used as a natural food preservative. Copyright © 2015
Ballester, Ferran; Iñiguez, Carmen; Murcia, Mario; Guxens, Mònica; Basterretxea, Mikel; Rebagliato, Marisa; Vioque, Jesús; Lertxundi, Aitana; Fernandez-Somoano, Ana; Tardon, Adonina; Sunyer, Jordi; Llop, Sabrina
2018-01-01
Prenatal mercury exposure has been related to reductions in anthropometry at birth. Levels of mercury have been reported as being relatively elevated in the Spanish population. To investigate the relation between prenatal exposure to mercury and fetal growth. Study subjects were pregnant women and their newborns (n:1867) participating in a population-based birth cohort study set up in four Spanish regions from the INMA Project. Biparietal diameter (BPD), femur length (FL), abdominal circumference (AC), and estimated fetal weight (EFW) were measured by ultrasounds at 12, 20, and 34 weeks of gestation. Size at and growth between these points were assessed by standard deviation (SD) scores adjusted for constitutional characteristics. Total mercury (T-Hg) was determined in cord blood. Associations were investigated by linear regression models, adjusted by sociodemographic, environmental, nutritional - including four seafood groups - and lifestyle-related variables in each sub-cohort. Final estimates were obtained using meta-analysis. Effect modification by sex, seafood intake and polychlorinated biphenyl (PCB) congener 153 concentration was assessed. Geometric mean of cord blood T-Hg was 8.2μg/L. All the estimates of the association between prenatal Hg and growth from 0 to 12 weeks showed reductions in SD-scores, which were only statistically significant for BPD. A doubling of cord blood T-Hg was associated with a 0.58% reduction in size of BPD at week 12 (95% confidence interval -CI-: - 1.10, - 0.07). Size at week 34 showed estimates suggestive of a small reduction in EFW, i.e., a doubling of T-Hg levels was associated with a reduction of 0.38% (95% CI: - 0.91, 0.15). An interaction between PCB153 and T-Hg was found, with statistically significant negative associations of T-Hg with AC and EFW in late pregnancy among participants with PCB153 below the median. Exposure to mercury during pregnancy was associated with early reductions in BPD. Moreover, an antagonism with
Energy Technology Data Exchange (ETDEWEB)
Bieler, Noah S.; Hünenberger, Philippe H., E-mail: phil@igc.phys.chem.ethz.ch [Laboratory of Physical Chemistry, ETH Zürich, CH-8093 Zürich (Switzerland)
2014-11-28
In a recent article [Bieler et al., J. Chem. Theory Comput. 10, 3006–3022 (2014)], we introduced a combination of the λ-dynamics (λD) approach for calculating alchemical free-energy differences and of the local-elevation umbrella-sampling (LEUS) memory-based biasing method to enhance the sampling along the alchemical coordinate. The combined scheme, referred to as λ-LEUS, was applied to the perturbation of hydroquinone to benzene in water as a test system, and found to represent an improvement over thermodynamic integration (TI) in terms of sampling efficiency at equivalent accuracy. However, the preoptimization of the biasing potential required in the λ-LEUS method requires “filling up” all the basins in the potential of mean force. This introduces a non-productive pre-sampling time that is system-dependent, and generally exceeds the corresponding equilibration time in a TI calculation. In this letter, a remedy is proposed to this problem, termed the slow growth memory guessing (SGMG) approach. Instead of initializing the biasing potential to zero at the start of the preoptimization, an approximate potential of mean force is estimated from a short slow growth calculation, and its negative used to construct the initial memory. Considering the same test system as in the preceding article, it is shown that of the application of SGMG in λ-LEUS permits to reduce the preoptimization time by about a factor of four.
International Nuclear Information System (INIS)
Bieler, Noah S.; Hünenberger, Philippe H.
2014-01-01
In a recent article [Bieler et al., J. Chem. Theory Comput. 10, 3006–3022 (2014)], we introduced a combination of the λ-dynamics (λD) approach for calculating alchemical free-energy differences and of the local-elevation umbrella-sampling (LEUS) memory-based biasing method to enhance the sampling along the alchemical coordinate. The combined scheme, referred to as λ-LEUS, was applied to the perturbation of hydroquinone to benzene in water as a test system, and found to represent an improvement over thermodynamic integration (TI) in terms of sampling efficiency at equivalent accuracy. However, the preoptimization of the biasing potential required in the λ-LEUS method requires “filling up” all the basins in the potential of mean force. This introduces a non-productive pre-sampling time that is system-dependent, and generally exceeds the corresponding equilibration time in a TI calculation. In this letter, a remedy is proposed to this problem, termed the slow growth memory guessing (SGMG) approach. Instead of initializing the biasing potential to zero at the start of the preoptimization, an approximate potential of mean force is estimated from a short slow growth calculation, and its negative used to construct the initial memory. Considering the same test system as in the preceding article, it is shown that of the application of SGMG in λ-LEUS permits to reduce the preoptimization time by about a factor of four
Pricing the Ramping Reserve and Capacity Reserve in Real Time Markets
Ye, Hongxing; Li, Zuyi
2015-01-01
The increasing penetration of renewable energy in recent years has led to more uncertainties in power systems. In order to maintain system reliability and security, electricity market operators need to keep certain reserves in the Security-Constrained Economic Dispatch (SCED) problems. A new concept, deliverable generation ramping reserve, is proposed in this paper. The prices of generation ramping reserves and generation capacity reserves are derived in the Affine Adjustable Robust Optimizat...
Stochastic models for tumoral growth
Escudero, Carlos
2006-02-01
Strong experimental evidence has indicated that tumor growth belongs to the molecular beam epitaxy universality class. This type of growth is characterized by the constraint of cell proliferation to the tumor border and the surface diffusion of cells at the growing edge. Tumor growth is thus conceived as a competition for space between the tumor and the host, and cell diffusion at the tumor border is an optimal strategy adopted for minimizing the pressure and helping tumor development. Two stochastic partial differential equations are reported in this paper in order to correctly model the physical properties of tumoral growth in (1+1) and (2+1) dimensions. The advantage of these models is that they reproduce the correct geometry of the tumor and are defined in terms of polar variables. An analysis of these models allows us to quantitatively estimate the response of the tumor to an unfavorable perturbation during growth.
Use and Limitations of the Reserve Requirement Policy in Montenegro
Directory of Open Access Journals (Sweden)
Milošević Velibor
2014-05-01
Full Text Available Since reserve requirement is the only monetary policy instrument used in Montenegro, it has been subject to frequent amendments since the global crisis outbreak. The analysis of the monetary demand model showed that there is an active transmission mechanism of change in the reserve requirement rate on the deposits trend reflects on lending activity. Also, there is a significant impact of FDIs on deposits trending in the banking system, as well as the positive impact of turnover on stock exchange on the deposits and loans trend. Finally, it was found that the financial crisis has caused negative trends in loans and deposits. On the other hand, the impact of changes in the reserve requirement on the economic activity in Montenegro could not be determined. This is primarily due to the fact that the transmission mechanism of the effect of reserve requirement on economic activity is too long to be able to estimate the model that does not allow the dynamics of the independent variables. The second reason is that industrial output index is only an indirect indicator of the economic activity.
District tops U.S. in growth of exports to China
Cletus C. Coughlin
2008-01-01
The states in the Eighth Federal Reserve District are reporting faster growth in exports to China than is the U.S. as a whole. Missouri is leading the region's pack, with an annual rate of growth topping 31 percent.
Export-led growth hypothesis : new evidence from Thirlwall's idea
Chee-Keong Choong; Zulkornain Yusop; Siong-Hook Law
2007-01-01
This study reexamines the relationship between exports and economic growth in ten East Asian and Pacific economies by building upon Verdoorn's [1941] idea. The cointegration tests indicate the existence of long-run and stable relationships between economic growth, exports, imports, capital, and labor in each economy. Granger-causality tests indicate short-run in causality (either export-led growth or growth-driven exports) in most economies. Besides, among the long-run estimated coefficients ...
Error estimates in horocycle averages asymptotics: challenges from string theory
Cardella, M.A.
2010-01-01
For modular functions of rapid decay, a classical result connects the error estimate in their long horocycle average asymptotic to the Riemann hypothesis. We study similar asymptotics, for modular functions with not that mild growing conditions, such as of polynomial growth and of exponential growth
How does political instability affect economic growth?
Aisen, Ari; Veiga, Francisco José
2011-01-01
The purpose of this paper is to empirically determine the effects of political instability on economic growth. Using the system-GMM estimator for linear dynamic panel data models on a sample covering up to 169 countries, and 5-year periods from 1960 to 2004, we find that higher degrees of political instability are associated with lower growth rates of GDP per capita. Regarding the channels of transmission, we find that political instability adversely affects growth by lowering the rates of pr...
DEFF Research Database (Denmark)
Møller, S.; Sternberg, Claus; Poulsen, L. K.
1995-01-01
species-specific hybridizations with fluorescence-labelled ribosomal probes to estimate the single-cell concentration of RNA. By automated analysis of digitized images of stained cells, we determined four independent growth rate-related parameters: cellular RNA and DNA contents, cell volume......, and the frequency of dividing cells in a cell population. These parameters were used to compare physiological states of liquid-suspended and surfacegrowing Pseudomonas putida KT2442 in chemostat cultures. The major finding is that the correlation between substrate availability and cellular growth rate found...
Buying versus exploring for reserves in the Canadian oil industry
International Nuclear Information System (INIS)
Sayer, F.
1992-01-01
The issue of a business strategy for Canadian oil companies focussed on either buying reserves or on exploration is examined. A measurement of the amount of merger and acquisition (M ampersand A) transactions vs the amount of exploration activity shows that the number of M ampersand A transactions has risen from 262 in 1989 to an estimated 1,500 in 1992. This sales activity has partly resulted from major companies selling assets to pay down debt. In the same period, the number of licensed exploration wells has decreased from 2,800 to 1,500. An analysis of statistics on the costs of acquisitions vs cost of finding and development shows acquisitions costs are lower in all cases. In addition, the median acquisition price has been falling steadily. Buying reserves has other advantages, including the fact that reserves can be added more quickly, lower risk, and readily available financing. Exploration, however, has its advantages, including the potential for very large reserve additions, higher tax deductions and incentives available, less competition from the industry, and low input costs. The acquisition vs exploration strategies are illustrated using the stock performance of two companies. If the acquisitions trend continues, there will be increases in the profitability of existing reserves, the number of companies, and tax receipts, However, in the long term there will be a drop in Canadian reserves and a significant reduction in the size of the industry. 14 figs., 2 tabs
Estimating nitrogen oxides emissions at city scale in China with a nightlight remote sensing model.
Jiang, Jianhui; Zhang, Jianying; Zhang, Yangwei; Zhang, Chunlong; Tian, Guangming
2016-02-15
Increasing nitrogen oxides (NOx) emissions over the fast developing regions have been of great concern due to their critical associations with the aggravated haze and climate change. However, little geographically specific data exists for estimating spatio-temporal trends of NOx emissions. In order to quantify the spatial and temporal variations of NOx emissions, a spatially explicit approach based on the continuous satellite observations of artificial nighttime stable lights (NSLs) from the Defense Meteorological Satellite Program/Operational Linescan System (DMSP/OLS) was developed to estimate NOx emissions from the largest emission source of fossil fuel combustion. The NSL based model was established with three types of data including satellite data of nighttime stable lights, geographical data of administrative boundaries, and provincial energy consumptions in China, where a significant growth of NOx emission has experienced during three policy stages corresponding to the 9th-11th)Five-Year Plan (FYP, 1995-2010). The estimated national NOx emissions increased by 8.2% per year during the study period, and the total annual NOx emissions in China estimated by the NSL-based model were approximately 4.1%-13.8% higher than the previous estimates. The spatio-temporal variations of NOx emissions at city scale were then evaluated by the Moran's I indices. The global Moran's I indices for measuring spatial agglomerations of China's NOx emission increased by 50.7% during 1995-2010. Although the inland cities have shown larger contribution to the emission growth than the more developed coastal cities since 2005, the High-High clusters of NOx emission located in Beijing-Tianjin-Hebei regions, the Yangtze River Delta, and the Pearl River Delta should still be the major focus of NOx mitigation. Our results indicate that the readily available DMSP/OLS nighttime stable lights based model could be an easily accessible and effective tool for achieving strategic decision making
Moorman, Benjamin P; Yamaguchi, Yoko; Lerner, Darren T; Grau, E Gordon; Seale, Andre P
2016-08-01
The growth hormone (GH)/insulin-like growth factor (IGF) axis plays a central role in the regulation of growth in teleosts and has been shown to be affected by acclimation salinity. This study was aimed at characterizing the effects of rearing tilapia, Oreochromis mossambicus, in a tidally-changing salinity on the GH/IGF axis and growth. Tilapia were raised in fresh water (FW), seawater (SW), or in a tidally-changing environment, in which salinity is switched between FW (TF) and SW (TS) every 6h, for 4months. Growth was measured over all time points recorded and fish reared in a tidally-changing environment grew significantly faster than other groups. The levels of circulating growth hormone (GH), insulin-like growth factor I (IGF-I), pituitary GH mRNA, gene expression of IGF-I, IGF-II, and growth hormone receptor 2 (GHR) in the muscle and liver were also determined. Plasma IGF-I was higher in FW and TS than in SW and TF tilapia. Pituitary GH mRNA was higher in TF and TS than in FW and SW tilapia. Gene expression of IGF-I in the liver and of GHR in both the muscle and liver changed between TF and TS fish. Fish growth was positively correlated with GH mRNA expression in the pituitary, and GHR mRNA expression in muscle and liver tissues. Our study indicates that rearing fish under tidally-changing salinities elicits a distinct pattern of endocrine regulation from that observed in fish reared in steady-state conditions, and may provide a new approach to increase tilapia growth rate and study the regulation of growth in euryhaline fish. Copyright © 2016 Elsevier Inc. All rights reserved.
Growth rates of alien Oreochromis niloticus and indigenous ...
African Journals Online (AJOL)
Growth rates of indigenous Oreochromis mortimeri and alien Oreochromis niloticus from Lake Kariba were estimated from samples collected in 1997–2000, 2003–2005 and 2010–2011. Growth zones on scales and otoliths of O. niloticus and on the otoliths and opercula of O. mortimeri were deposited annually.
Review article: Vegetative growth, reproduction, browse production ...
African Journals Online (AJOL)
Vegetative growth, reproduction, browse production and response to tree clearing of ... water stress, soil nutrient availability, carbohydrate reserves, plant hormones, ... animal-plant interactions) of woody plants in various savanna ecosystems.
Three essays on energy and economic growth
Peach, Nathanael David
2011-12-01
This dissertation explores the relationship between energy and economic growth. Chapter Two, Three, and Four examine the interaction of energy-related measures and economic outcomes by applying different methodologies across various spatial dimensions. Chapter Two shows that increases in energy consumption are necessary for increases in state level economic growth to occur. Chapter Three estimates a simultaneous supply and demand energy market at the state level. This system allows for estimates of structural elasticities to be obtained. Findings indicate that energy supply is considerably more elastic than energy demand. Energy demand is found to be determined by responses to short run shocks rather than long run processes. Chapter Four estimates the impact of changes in various elements of governance and institutional quality impact genuine investment within an economy. Increases in democracy are predicted to decrease genuine investment in energy-rich nations. The dissertation concludes with Chapter Five.
An evaluation of the choice of feeder cell growth arrest for the production of cultured epidermis.
Chugh, Rishi Man; Chaturvedi, Madhusudan; Yerneni, Lakshmana Kumar
2015-12-01
Growth arrested 3T3 cells have been used as feeder cells in human epidermal keratinocyte cultures to produce cultured epidermal autografts for the treatment of burns. The feeder cells were ideally growth-arrested by gamma-irradiation. Alternatively, growth arrest by mitomycin C treatment is a cost effective option. We compared the functional efficacy of these two approaches in keratinocyte cultures by colony forming efficiency, the net growth area of colonies, BrdU labeling and histological features of cultured epidermal sheets. The growth area estimation involved a semi-automated digital technique using the Adobe Photoshop and comprised of isolation and enumeration of red pixels in Rhodamine B-stained keratinocyte colonies. A further refinement of the technique led to the identification of critical steps to increasing the degree of accuracy and enabling its application as an extension of colony formation assay. The results on feeder cell functionality revealed that the gamma irradiated feeders influenced significantly higher colony forming efficiency and larger growth area than the mitomycin C treated feeders. The BrdU labeling study indicated significant stimulation of the overall keratinocyte proliferation by the gamma irradiated feeders. The cultured epidermal sheets produced by gamma feeders were relatively thicker than those produced by mitomycin C feeders. We discussed the clinical utility of mitomycin C feeders from the viewpoint of cost-effective burn care in developing countries. Copyright © 2015 Elsevier Ltd and ISBI. All rights reserved.
Benchmarking passive transfer of immunity and growth in dairy calves.
Atkinson, D J; von Keyserlingk, M A G; Weary, D M
2017-05-01
Poor health and growth in young dairy calves can have lasting effects on their development and future production. This study benchmarked calf-rearing outcomes in a cohort of Canadian dairy farms, reported these findings back to producers and their veterinarians, and documented the results. A total of 18 Holstein dairy farms were recruited, all in British Columbia. Blood samples were collected from calves aged 1 to 7 d. We estimated serum total protein levels using digital refractometry, and failure of passive transfer (FPT) was defined as values below 5.2 g/dL. We estimated average daily gain (ADG) for preweaned heifers (1 to 70 d old) using heart-girth tape measurements, and analyzed early (≤35 d) and late (>35 d) growth separately. At first assessment, the average farm FPT rate was 16%. Overall, ADG was 0.68 kg/d, with early and late growth rates of 0.51 and 0.90 kg/d, respectively. Following delivery of the benchmark reports, all participants volunteered to undergo a second assessment. The majority (83%) made at least 1 change in their colostrum-management or milk-feeding practices, including increased colostrum at first feeding, reduced time to first colostrum, and increased initial and maximum daily milk allowances. The farms that made these changes experienced improved outcomes. On the 11 farms that made changes to improve colostrum feeding, the rate of FPT declined from 21 ± 10% before benchmarking to 11 ± 10% after making the changes. On the 10 farms that made changes to improve calf growth, ADG improved from 0.66 ± 0.09 kg/d before benchmarking to 0.72 ± 0.08 kg/d after making the management changes. Increases in ADG were greatest in the early milk-feeding period, averaging 0.13 kg/d higher than pre-benchmarking values for calves ≤35 d of age. Benchmarking specific outcomes associated with calf rearing can motivate producer engagement in calf care, leading to improved outcomes for calves on farms that apply relevant management changes. Copyright
Directory of Open Access Journals (Sweden)
Andre Bellucco
2004-12-01
Full Text Available This paper on the otolith microstructure analysis of Maurolicus stehmanni presents estimates of the species growth parameters and longevity. The species inhabits the outer shelf and slope of the southern and southeastern Brazilian Exclusive Economic Zone (EEZ. Growth parameters are important for the knowledge of the species' life history and rational management. M. stehmanni constitutes an important link between the initial and final components of the alimentary chain of the open sea ecosystem, being one of the main food items for squids and large pelagic fish. Among the various applied methods those which presented the most coherent values for growth parameters and were best adapted to the von Bertallanfy's equation were: Li= 55mm K= 0.0088/day and to= 5.5 days Maurolicus stehmanni's longevity is of less than one year (around 220 days and the sagita daily otolith rings are useful for the determination of its age.Este estudo, baseado na análise da microestrutura dos otólitos de Maurolicus stehmanni, apresenta estimativas dos parâmetros de crescimento e longevidade para esta espécie que habita a plataforma externa e o talude da ZEE sul-sudeste do Brasil. Estes parâmetros são importantes para o conhecimento da estratégia de vida da espécie e para o manejo deste recurso, que constitui um importante elo entre os componentes iniciais e finais da teia alimentar no ecossistema de mar aberto, sendo um dos principais itens na dieta das lulas e grandes peixes pelágicos. Dentre os vários métodos aplicados, os valores dos parâmetros de crescimento mais coerentes com a estratégia da espécie e que melhor se ajustaram à equação de von Bertallanfy foram: Li= 55mm K= 0.0088/dia e to= 5.5 dias. A espécie vive cerca de 220 dias e as marcas diárias nos otólitos sagita são apropriadas para a determinação da idade.
A mathematical model of microalgae growth in cylindrical photobioreactor
Bakeri, Noorhadila Mohd; Jamaian, Siti Suhana
2017-08-01
Microalgae are unicellular organisms, which exist individually or in chains or groups but can be utilized in many applications. Researchers have done various efforts in order to increase the growth rate of microalgae. Microalgae have a potential as an effective tool for wastewater treatment, besides as a replacement for natural fuel such as coal and biodiesel. The growth of microalgae can be estimated by using Geider model, which this model is based on photosynthesis irradiance curve (PI-curve) and focused on flat panel photobioreactor. Therefore, in this study a mathematical model for microalgae growth in cylindrical photobioreactor is proposed based on the Geider model. The light irradiance is the crucial part that affects the growth rate of microalgae. The absorbed photon flux will be determined by calculating the average light irradiance in a cylindrical system illuminated by unidirectional parallel flux and considering the cylinder as a collection of differential parallelepipeds. Results from this study showed that the specific growth rate of microalgae increases until the constant level is achieved. Therefore, the proposed mathematical model can be used to estimate the rate of microalgae growth in cylindrical photobioreactor.
Effects of Credit on Economic Growth, Unemployment and Poverty
Sipahutar, Mangasa Augustinus
2016-01-01
Abstract Effect of credit on economic growth, unemployment and poverty provides evidence from Indonesia on the role of banks credit for promoting economic growth and reducing both unemployment and poverty. To document the link between banks credit and economic growth, we estimate a VAR model and variance decompositions of annual GDP per capita growth rates to examine what proxy measures of banks credit are most important in accounting for economic growth over time and ho...
China and India: Openness, Trade and Effects on Economic Growth
Directory of Open Access Journals (Sweden)
Marelli, Enrico
2011-06-01
Full Text Available The purpose of this paper is to analyse the economic growth of China and India in terms of their integration in the global economy. We begin with a discussion of some stylized facts concerning their recent economic growth, the most significant institutional reforms, with particular reference to trade relations, and their impact on their economic development. We then propose a descriptive analysis of economic growth, opening up of the economies and trade specialisation, by comparing the features and trends of the two countries (by considering trade and foreign direct investment data. We have also estimated some econometric relations between economic growth and trade/openness, with the addition of control variables (such as the gross fixed capital formation. We initially used a panel data model for the two countries, to be estimated with fixed effects; to test for reverse causality, we re-estimated the fixed effects model by 2SLS (with the inclusion of specific instrumental variables. The effect on economic growth (in terms of GDP per capita of our variables of interest - Openness and FDI - remains positive and statistically significant in all specifications, which confirms our findings even if we treat these variables as endogenous variables. The results prove the positive growth effects, for the two countries, of opening up and integrating in the world economy. Note that the robust growth of these two "giants" has contained the initial impact of the recent global crisis and is now sustaining the recovery of the entire world economy. Other policy relevant implications are discussed in the concluding section.
Estimation of heritability and genetic gain in height growth in Ceiba ...
African Journals Online (AJOL)
However, there is relatively inefficient information available on the heritability and genetic gain in height growth in C. pentandra based on which selection and subsequent breeding could be made. This poses a major challenge to the production of new cultivars for the forestry industry of Ghana. The current study looked at ...
Energy consumption and economic growth
Energy Technology Data Exchange (ETDEWEB)
Brookes, L G
1972-10-01
A mathematical model relating Gross National Product (GNP) per capita to useful energy consumed per capita is demonstrated to predict the shift in this relationship actually experienced in the U.K. and the U.S. over a period of years. World GNP growths in the recent past are used to forecast GNP growth to the year 2030 and also (via the model) the necessary fuel consumption for such growth; likewise, potential production of fossil fuels (exclusive of tar sands and oil shale) is shown to 2030, based on two different assumptions about total world reserves. Fossil fuel ceases to meet world requirements for energy at some time between 1985 and 1995. The most likely candidate for filling the gap is nuclear power.
Financial Development and Output Growth: A Panel Study for Asian Countries
Directory of Open Access Journals (Sweden)
Sangjoon Jun
2012-03-01
Full Text Available This paper investigates the relationship between financial markets and output growth for a panel of 27 Asian countries over 1960-2009. It utilizes the recently-developed panel cointegration techniques to test and estimate the long-run equilibrium relationship between real GDP and financial development proxies. Real GDP and financial development variables are found to have unit roots and to be cointegrated, based on various panel unit root tests and panel cointegration tests. We find that there is a statistically significant positive bi-directional cointegrating relationship between financial development and output growth by three distinct methods of panel cointegration estimation. Empirical findings suggest that financial market development promotes output growth and in turn output growth stimulates further financial development.
Gizzo, Salvatore; Andrisani, Alessandra; Noventa, Marco; Quaranta, Michela; Esposito, Federica; Armanini, Decio; Gangemi, Michele; Nardelli, Giovanni B; Litta, Pietro; D'Antona, Donato; Ambrosini, Guido
2015-04-10
Aim of the study was to investigate whether menstrual cycle length may be considered as a surrogate measure of reproductive health, improving the accuracy of biochemical/sonographical ovarian reserve test in estimating the reproductive chances of women referred to ART. A retrospective-observational-study in Padua' public tertiary level Centre was conducted. A total of 455 normo-ovulatory infertile women scheduled for their first fresh non-donor IVF/ICSI treatment. The mean menstrual cycle length (MCL) during the preceding 6 months was calculated by physicians on the basis of information contained in our electronic database (first day of menstrual cycle collected every month by telephonic communication by single patients). We evaluated the relations between MCL, ovarian response to stimulation protocol, oocytes fertilization ratio, ovarian sensitivity index (OSI) and pregnancy rate in different cohorts of patients according to the class of age and the estimated ovarian reserve. In women younger than 35 years, MCL over 31 days may be associated with an increased risk of OHSS and with a good OSI. In women older than 35 years, and particularly than 40 years, MCL shortening may be considered as a marker of ovarian aging and may be associated with poor ovarian response, low OSI and reduced fertilization rate. When AMH serum value is lower than 1.1 ng/ml in patients older than 40 years, MCL may help Clinicians discriminate real from expected poor responders. Considering the pool of normoresponders, MCL was not correlated with pregnancy rate while a positive association was found with patients' age. MCL diary is more predictive than chronological age in estimating ovarian biological age and response to COH and it is more predictive than AMH in discriminating expected from real poor responders. In women older than 35 years MCL shortening may be considered as a marker of ovarian aging while chronological age remains most accurate parameter in predicting pregnancy.
Economic Growth, Economic Freedom, and Governance
Cebula, Richard; Ekstrom, Marcus
2008-01-01
This exploratory study examines the impact of various forms of economic freedom and various dimensions of governance, as well as a number of economic factors, on economic growth among OECD nations. Empirical estimation finds that the natural log of per capita purchasing-power-parity adjusted real GDP in OECD nations is positively impacted by business freedom, monetary freedom, trade freedom, and property rights security. Economic growth is found to be negatively affected by perceived governme...
Bittencourt, MarcosAlan Vieira; Cericato, GrazielaOro; Franco, Ademir; Girão, RafaelaSilva; Lima, Anderson Paulo Barbosa; Paranhos, LuizRenato
2018-05-01
This study aimed to search for scientific evidence concerning the accuracy of dental development for estimating the pubertal growth spurt. It was conducted according to the statements of PRISMA. An electronic search was performed in six databases, including the grey literature. The PICOS strategy was used to define the eligibility criteria and only observational studies were selected. Out of 1,416 identified citations, 10 articles fulfilled the criteria and were included in this systematic review. The association between dental development and skeletal maturity was considered strong in seven studies, and moderate in two, although the association with the pubertal growth spurt had been verified in only four articles. According to half of the studies, the tooth that provided the greater association with the ossification centres was the lower canine. The meta-analysis performed also indicated a positive association, being stronger in females [0.725 (0.649-0.808)]. However, when the method used for dental evaluation was considered, it was possible to verify greater correlation coefficients for Nolla [0.736 (0.666-0.814)] than for Demirjian [0.631 (0.450-0.884)], at the boys sample. The heterogeneity test reached high values (Q = 51.00), suggesting a potential bias within the studies. Most of individual studies suggested a strong correlation between dental development and skeletal maturation, although the association with the peakof pubertal growth spurtwas clearly cited only in some of them. However, due to the high heterogeneity found among the studies included in this meta-analysis, a pragmatic recommendation about the use of dental stages is not possible.
Energy reserves and energy resources: situation in 1980
International Nuclear Information System (INIS)
Bauer, L.
1981-01-01
Following an explanation of the main relevant technical terms and units, the author discusses the world energy consumption over the last few years and its structural development. This is supplemented by an analysis of energy consumption in Austria. Based on this, the author gives a forecast of the further growth of the world energy consumption figures to the year 2020 and compares these with the world's reserves of raw materials for energy production. A similar comparison is made for Austria. Outlining the irregularity in the distribution of the reserves over the earth and a short explanation of the dependence on the respective technology of the utilisation of nuclear fuels, the author discusses the possibilities of developing the energy resources all over the world as well as in Austria. The quantitative assessment is based on IIASA studies and on corresponding investigations carried out in Austria. By way of summary, he presents an outlook on the possibilities of upgrading solid fuels as a temporary remedy against future difficulties in the supply of crude oil or natural gas and underlines the importance of nuclear energy for the future. (Auth.)
Elephant crop damage and electric fence construction in the Maputo Elephant Reserve, Mozambique
Boer, de W.F.; Ntumi, C.P.
2001-01-01
An electric fence is at present being constructed around the Maputo Elephant Reserve, Mozambique, to protect farmers from elephant raids. Elephants cause crop damage, estimated at US$ 8800 yr-1, or US$ 50 elephant-1. Elephants preferred maize, melons and beans and their raid frequency increased
Morin-Sardin, Stéphanie; Rigalma, Karim; Coroller, Louis; Jany, Jean-Luc; Coton, Emmanuel
2016-06-01
The Mucor genus includes a large number of ubiquitous fungal species. In the dairy environment, some of them play a technological role providing typical organoleptic qualities to some cheeses while others can cause spoilage. In this study, we compared the effect of relevant abiotic factors for cheese production on the growth of six strains representative of dairy technological and contaminant species as well as of a non cheese related strain (plant endophyte). Growth kinetics were determined for each strain in function of temperature, water activity and pH on synthetic Potato Dextrose Agar (PDA), and secondary models were fitted to calculate the corresponding specific cardinal values. Using these values and growth kinetics acquired at 15 °C on cheese agar medium (CA) along with three different cheese types, optimal growth rates (μopt) were estimated and consequently used to establish a predictive model. Contrarily to contaminant strains, technological strains showed higher μopt on cheese matrices than on PDA. Interestingly, lag times of the endophyte strain were strongly extended on cheese related matrices. This study offers a relevant predictive model of growth that may be used for better cheese production control but also raises the question of adaptation of some Mucor strains to the cheese. Copyright © 2015 Elsevier Ltd. All rights reserved.
Growth effects of EU and EZ memberships
DEFF Research Database (Denmark)
Dreyer, Johannes Kabderian; Schmid, Peter A.
2017-01-01
of economic integration in Europe. The aim of this article is to investigate whether EU and EZ memberships enhance growth for their members. In order to perform our empirical analysis, we estimate different growth models restricting the time frame to the first 15 years of the Euro - from 1999 to 2013. We find...... a positive impact of EU membership on economic growth, but no impact of being part of the EZ, except during the financial crisis, when the EZ has a negative impact on growth amongst its members. Considering the heated political debate related to the Brexit referendum, our results favour a “yes” to the EU...
Uncertainty Estimate in Resources Assessment: A Geostatistical Contribution
International Nuclear Information System (INIS)
Souza, Luis Eduardo de; Costa, Joao Felipe C. L.; Koppe, Jair C.
2004-01-01
For many decades the mining industry regarded resources/reserves estimation and classification as a mere calculation requiring basic mathematical and geological knowledge. Most methods were based on geometrical procedures and spatial data distribution. Therefore, uncertainty associated with tonnages and grades either were ignored or mishandled, although various mining codes require a measure of confidence in the values reported. Traditional methods fail in reporting the level of confidence in the quantities and grades. Conversely, kriging is known to provide the best estimate and its associated variance. Among kriging methods, Ordinary Kriging (OK) probably is the most widely used one for mineral resource/reserve estimation, mainly because of its robustness and its facility in uncertainty assessment by using the kriging variance. It also is known that OK variance is unable to recognize local data variability, an important issue when heterogeneous mineral deposits with higher and poorer grade zones are being evaluated. Alternatively, stochastic simulation are used to build local or global uncertainty about a geological attribute respecting its statistical moments. This study investigates methods capable of incorporating uncertainty to the estimates of resources and reserves via OK and sequential gaussian and sequential indicator simulation The results showed that for the type of mineralization studied all methods classified the tonnages similarly. The methods are illustrated using an exploration drill hole data sets from a large Brazilian coal deposit
Directory of Open Access Journals (Sweden)
V. I. Golik
2017-12-01
Full Text Available The underground mining of the ore deposits by means of the intensive methods of the traditional technologies is characterized by the loss of the reserves, which are off-balance for the technologies applied. The experience, which was accumulated by the state-of-the-art enterprises before the economic reforms and the crisis indicates, that it is possible to decrease the loss of metals. This can be assumed by means of involving the off-balance reserves into the production process with the metal lixiviation during closed work. The purpose of the present-day research is the substantiation of the technical possibility and economic reasonability of the lixiviation of metals from the off-balance reserves and poorly balance ores. The correct estimation of the perspectives of those combined technology is still one of the purposes. It is a matter of fact that combining traditional technologies of the underground mining with new ones concerned with the creation of the effective lixiviation of metals from ores can be carried out with the two-stage processing. It happens when the excavation of some amount of the balance reserves creates the compensational space for crushing off-balance reserves. Involving off-balance ores into the production process solves a set of the mining production problems. For example, the fullness of mineral resources usage, the strengthening of the resource base, the reduction of load of the environment and the security of works. The involvement of the off-balance reserves into the development in the course of the revaluation of the resources and in the technological facilities of the development in the context of the growth of the scale of production reduces the production price to the competitive level. The field of application of these results is in the mining enterprises which extract solid metal-containing ores by means of the underground mining. These ores are mostly of the nonferrous, rare and precious metals, which are easily
Income growth, government spending, and wasting assets: Alberta's oil and gas
International Nuclear Information System (INIS)
Smith, R.S.
1992-01-01
Physical and monetary accounts for the oil and gas sectors in Alberta from 1963 through 1988 are used to adjust Alberta's Gross Domestic Product and Gross Domestic Investment for changes in oil and gas reserves. Other resources, non-renewable and renewable, are important to Alberta, but the change in oil and gas reserves over the past quarter century deserves attention in itself. Growth rates of income and investment during the 1970s and 1980s differ significantly when the adjustments are made to conventional income accounts. Since policies are often based on conventional statistics, alternative measures yielding very different results warrant attention. The oil and gas accounts also permit comparison of past expenditures of resource revenues with what would be spent under a rule of thumb such as Robert Solow's (1986) suggestion that allowable consumption be interest on an initial patrimony of resource endowment. Such a comparison indicates the provincial government may, at times, have overspent resource revenues during the past quarter century; at other times its policies appear to have been quite conservative. The estimates presented require various assumptions, and therefore are but one possible set of adjustments deserving consideration. 26 refs., 4 figs., 13 tabs
Greenhouse gas emissions from operating reserves used to backup large-scale wind power.
Fripp, Matthias
2011-11-01
Wind farms provide electricity with no direct emissions. However, their output cannot be forecasted perfectly, even a short time ahead. Consequently, power systems with large amounts of wind power may need to keep extra fossil-fired generators turned on and ready to provide power if wind farm output drops unexpectedly. In this work, I introduce a new model for estimating the uncertainty in short-term wind power forecasts, and how this uncertainty varies as wind power is aggregated over larger regions. I then use this model to estimate the reserve requirements in order to compensate for wind forecast errors to a 99.999% level of reliability, and an upper limit on the amount of carbon dioxide that would be emitted if natural gas power plants are used for this purpose. I find that for regions larger than 500 km across, operating reserves will undo 6% or less of the greenhouse gas emission savings that would otherwise be expected from wind power.
Prediction of the Maximum Number of Repetitions and Repetitions in Reserve From Barbell Velocity.
García-Ramos, Amador; Torrejón, Alejandro; Feriche, Belén; Morales-Artacho, Antonio J; Pérez-Castilla, Alejandro; Padial, Paulino; Haff, Guy Gregory
2018-03-01
To provide 2 general equations to estimate the maximum possible number of repetitions (XRM) from the mean velocity (MV) of the barbell and the MV associated with a given number of repetitions in reserve, as well as to determine the between-sessions reliability of the MV associated with each XRM. After determination of the bench-press 1-repetition maximum (1RM; 1.15 ± 0.21 kg/kg body mass), 21 men (age 23.0 ± 2.7 y, body mass 72.7 ± 8.3 kg, body height 1.77 ± 0.07 m) completed 4 sets of as many repetitions as possible against relative loads of 60%1RM, 70%1RM, 80%1RM, and 90%1RM over 2 separate sessions. The different loads were tested in a randomized order with 10 min of rest between them. All repetitions were performed at the maximum intended velocity. Both the general equation to predict the XRM from the fastest MV of the set (CV = 15.8-18.5%) and the general equation to predict MV associated with a given number of repetitions in reserve (CV = 14.6-28.8%) failed to provide data with acceptable between-subjects variability. However, a strong relationship (median r 2 = .984) and acceptable reliability (CV .85) were observed between the fastest MV of the set and the XRM when considering individual data. These results indicate that generalized group equations are not acceptable methods for estimating the XRM-MV relationship or the number of repetitions in reserve. When attempting to estimate the XRM-MV relationship, one must use individualized relationships to objectively estimate the exact number of repetitions that can be performed in a training set.
An Update on Ovarian Aging and Ovarian Reserve Tests
Directory of Open Access Journals (Sweden)
Migraci Tosun
2016-12-01
Full Text Available Ovaries are the female organs that age more quickly than other tissues such as the uterus, the pituitary gland or pancreas. Different from males, an interesting question is why and how the females lose fertility so rapidly. During the aging process, both the number and quality of the oocytes in the ovaries decrease and reach to a point beyond that no more viable offspring may be produced and the associated cyclic endocrinological activities cease, entering the menopause in females at an average age of 50 years. Females who delayed childbearing with or without their willing until their 30 years or 40 years constitute the largest portion of the total infertility population. Ovarian reserve tests (ORTs provide an indirect estimate of a female�s diminishing ovarian reserve or remaining follicular pool. This article briefly reviews recent progresses in relation to ovarian aging and ORTs.
A characterization and determination of the coal reserves and resources of southwest Virginia
Westman, Erik Christian
Coal mining has been the primary industry of Southwest Virginia for more than 100 years. Coal production increased steadily until it reached a peak in 1990. Since then it has begun a decline, accompanied by decreasing coal revenues to the region. In order to more effectively plan the future economy of the area a study was conducted to characterize and estimate remaining coal resources. Seam thickness was found to be the parameter which most influenced resource levels. An economic model was developed to determine which portion of the reserves could economically be extracted. It was found that 3.95 billion tons, or 14% of the remaining resource, are economic under current mining conditions. Many of these reserves, however, occur in seams at depths which require costly development prior to initiation of mining. The database used for the study was found to be accurate, but imprecise. Based on the quantitative measurements of accuracy and precision, a reserve quantity of 1.6 billion tons should be used for planning purposes. The precision of the database can be improved with additional data. A program encouraging the mining industry to submit their data to the state, while ensuring confidentiality, would allow more precise estimates to be made, ultimately benefiting all members of the Southwest Virginia community.
Directory of Open Access Journals (Sweden)
Emmanuelle Dortel
Full Text Available Age estimates, typically determined by counting periodic growth increments in calcified structures of vertebrates, are the basis of population dynamics models used for managing exploited or threatened species. In fisheries research, the use of otolith growth rings as an indicator of fish age has increased considerably in recent decades. However, otolith readings include various sources of uncertainty. Current ageing methods, which converts an average count of rings into age, only provide periodic age estimates in which the range of uncertainty is fully ignored. In this study, we describe a hierarchical model for estimating individual ages from repeated otolith readings. The model was developed within a Bayesian framework to explicitly represent the sources of uncertainty associated with age estimation, to allow for individual variations and to include knowledge on parameters from expertise. The performance of the proposed model was examined through simulations, and then it was coupled to a two-stanza somatic growth model to evaluate the impact of the age estimation method on the age composition of commercial fisheries catches. We illustrate our approach using the sagittal otoliths of yellowfin tuna of the Indian Ocean collected through large-scale mark-recapture experiments. The simulation performance suggested that the ageing error model was able to estimate the ageing biases and provide accurate age estimates, regardless of the age of the fish. Coupled with the growth model, this approach appeared suitable for modeling the growth of Indian Ocean yellowfin and is consistent with findings of previous studies. The simulations showed that the choice of the ageing method can strongly affect growth estimates with subsequent implications for age-structured data used as inputs for population models. Finally, our modeling approach revealed particularly useful to reflect uncertainty around age estimates into the process of growth estimation and it can
The South African tax mix and economic growth
AH de Wet; NJ Schoeman; SF Koch
2014-01-01
The research reported in this paper suggests that government fiscal policy can influence economic growth through alterations in the tax mix and the overall size of government spending. The authors estimate the impact on economic growth of changes in fiscal policy via government expenditure, direct taxation and indirect taxation. The results show that economic growth is negatively affected by increases in the size of government, as reflected in its expenditures and direct tax revenues, alth...
Bias factors for radiation creep, growth and swelling
International Nuclear Information System (INIS)
Nichols, F.A.
1980-01-01
Central to the present concepts of the origin of the radiation-induced creep, growth and swelling phenomena is the relative interaction of interstitials and vacancies with various sinks. Radiation-induced climb of dislocations, which figures in many theories of radiation creep and growth, requires the absorption of an excess of either vacancies or interstitials. On the other hand, radiation swelling requires the absorption of an excess of vacancies to effect void growth. These relative preferences are normally expressed in theoretical models by certain bias factors, or capture efficiencies, usually assumed to be constant. Several attempts have been made to estimate their magnitude theoretically but all are seen to involve errors or physically unrealistic assumptions. We present here a unified treatment in which these various bias factors are estimated in a self-consistent model which incorporates, for the first time, all the essential physics, i.e., defect production, interactions of both vacancies and interstitials with sinks and the presence of two types of sinks. We present quantitative evaluations for the SIPA creep model and for radiation swelling, and compare with previous estimates of these phenomena. (orig.)
World statistics on natural gas reserves, production and utilization
International Nuclear Information System (INIS)
Raikaslehto, S.
2001-01-01
By reviewing the statistics of BP Amoco on natural gas reserves, production and usage, it is easy to see that Russia and USA, both being large natural gas producers, differ significantly from each other. The natural gas reserves of USA are 6th largest in the world, simultaneously the natural gas consumption and import are largest in the world. About one third of the known natural gas reserves of the world are in Russia. The known natural gas reserves of both USA and Canada have decreases, but they have potential gas reserves left. Known natural gas reserves of the USA have been calculated to be sufficient for 9 years consumption at present usage and those of Canada for 11 years. The reserves of Algeria correspond to the usage of 55 years, and the Russian reserves for are about 83 years. Annual production figures of both Russia and the USA are nearly the same. Russia is the largest exporter (125.5 billion m 3 ) of natural gas and the USA the largest importer (96 billion m 3 ). The natural gas reserves of the largest European producers, the Netherlands and Norway have been estimated to be sufficient for use of about 20 years, but those of Great Britain only for about 10 years. The annual production of Russia has varied in the 1990s between nearly 600 billion m 3 and present 550 billion m 3 , the minimum being in 1997 only about 532 billion m 3 . Ten largest natural gas consumers use 67% of the natural gas consumed annually in the world. USA consumes about 27% of the total natural gas produced in the world, the amount of Russia being 364 billion m 3 (16%). Other large natural gas consumers are Great Britain, Germany, Japan, Ukraine, Canada, Italy, Iran and Uzbekistan. The share of these countries of the total consumption varied in between 2-4%. Only Japan has no natural gas production of its own. The foreign trade between Japan and Indonesia is trade on LNG. On the other hand the natural gas consumption of the world's 10th largest producer Norway is nearly zero, so
TOURIST ARRIVALS AND ECONOMIC GROWTH IN SARAWAK
Lau, Evan; Oh, Swee-Ling; Hu, Sing-Sing
2008-01-01
This study empirically investigates the comovements and the causality relationship between tourist arrivals and economic growth in Sarawak during the period of 1972 to 2004. The empirical evidence clearly shows that the long run causality running from tourist arrivals to economic growth in the estimation period. As one of the income generator for Sarawak, the findings are consistent with economic theory and proffer important policy conclusions.
Alencar, Nara L M; Innecco, Renato; Gomes-Filho, Enéas; Gallão, Maria Izabel; Alvarez-Pizarro, Juan C; Prisco, José T; Oliveira, Alexandre B De
2012-09-01
Cereus jamacaru, a Cactaceae found throughout northeast Brazil, is widely used as cattle food and as an ornamental and medicinal plant. However, there has been little information about the physiological and biochemical aspects involved in its germination. The aim of this study was to investigate its reserve mobilization during germination and early seedling growth. For this, C. jamacaru seeds were germinated in a growth chamber and collected at 0, 2, 4, 5, 6, 8 and 12 days after imbibition for morphological and biochemical analyses. Dry seeds had wrinkled seed coats and large, curved embryos. Lipids were the most abundant reserve, comprising approximately 55% and 65% of the dry mass for cotyledons and the hypocotylradicle axis, respectively. Soluble sugars and starch were the minor reserves, corresponding to approximately 2.2% of the cotyledons' dry mass, although their levels showed significant changes during germination. Soluble proteins corresponded to 40% of the cotyledons' dry mass, which was reduced by 81% at the final period of germination compared to dry seeds. C. jamacaru seed can be classified as an oil seed due to its high lipid content. Moreover, lipids were the main reserve mobilized during germination because their levels were strongly reduced after seed germination, while proteins were the second most utilized reserve in this process.
Development of composite indicator of Ukraine’s international reserves adequacy
Directory of Open Access Journals (Sweden)
Mykhaylo Makarenko
2015-11-01
Full Text Available This paper develops an indicator for estimating international reserves adequacy in Ukraine taking into account its unique characteristics. The proposed indicator was constructed based on the modification of IMF adequacy metric by changing weighting coefficients of potential balance of payments vulnerabilities based on historical data for Ukraine and by the inclusion of import as an additional component. In comparison to the IMF metric our indicator implies greater international reserves. This is due to the fact that balance of payments of Ukraine is very sensitive to current account shocks such as worsening terms of trade so our indicator except import component has increased weighting coefficient of export earnings. Also, compared to the IMF metrics our indicator provides more weighting coefficients of the other portfolio liabilities and the money supply that represents the sensitivity to financial account shocks. Reduced weighting coefficient of the short-term debt could be explained by the partial refinancing of external debt. This new indicator suggests that the accumulated levels of reserves of Ukraine have been inadequate at 1 April 2015.
Ethnic differences in fetal size and growth in a multi-ethnic population.
Sletner, Line; Rasmussen, Svein; Jenum, Anne Karen; Nakstad, Britt; Jensen, Odd Harald Rognerud; Vangen, Siri
2015-09-01
Impaired or excessive fetal growth is associated with adverse short- and long-term health outcomes that differ between ethnic groups. We explored ethnic differences in fetal size and growth from mid pregnancy until birth. Data are from the multi-ethnic STORK-Groruddalen study, a population-based, prospective cohort of 823 pregnant women and their offspring in Oslo, Norway. Measures were z-scores of estimated fetal weight (EFW), head circumference (HC), abdominal circumference (AC) and femur length (FL), in gestational week 24, 32 and 37, measured by ultrasound, and similar measures at birth. Differences in fetal size and growth were assessed using separate Linear Mixed Models including all four time points, with ethnic Europeans as reference. In week 24 South Asian fetuses had smaller AC, but larger FL than Europeans, and slightly lower EFW (-0.17 SD (-0.33, -0.01), p=0.04). Middle East/North African fetuses also had larger FL, but similar AC, and hence slightly higher EFW (0.18 (0.003, 0.36), p=0.05). Both groups had slower growth of AC, FL and EFW from this time until birth, and had -0.61 SD (-0.73, -0.49) and -0.28 SD (-0.41, -0.15) lower birth weight respectively. Ethnic East Asians, on the other hand, were smaller throughout pregnancy and had -0.58 SD (-0.82, -0.34) lower birth weight. Significant ethnic differences remained after adjusting for maternal factors. We observed ethnic differences in fetal size and body proportions already in gestational week 24, and in fetal growth from this time until birth, which were only partly explained by key maternal factors. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.
A Method of Nuclear Software Reliability Estimation
International Nuclear Information System (INIS)
Park, Gee Yong; Eom, Heung Seop; Cheon, Se Woo; Jang, Seung Cheol
2011-01-01
A method on estimating software reliability for nuclear safety software is proposed. This method is based on the software reliability growth model (SRGM) where the behavior of software failure is assumed to follow the non-homogeneous Poisson process. Several modeling schemes are presented in order to estimate and predict more precisely the number of software defects based on a few of software failure data. The Bayesian statistical inference is employed to estimate the model parameters by incorporating the software test cases into the model. It is identified that this method is capable of accurately estimating the remaining number of software defects which are on-demand type directly affecting safety trip functions. The software reliability can be estimated from a model equation and one method of obtaining the software reliability is proposed
Estimating Net Interracial Mobility in the U.S. A Residual Methods Approach.
Perez, Anthony Daniel; Hirschman, Charles
2009-08-01
This paper presents a residual methods approach to identifying social mobility across race/ethnic categories. In traditional demographic accounting models, population growth is limited to changes in natural increase and migration. Other sources of growth are absorbed by the model residual and can only be estimated indirectly. While these residual estimates have been used to illuminate a number of elusive demographic processes, there has been little effort to incorporate shifts in racial identification into formal accounts of population change. In light of growing evidence that a number of Americans view race/ethnic identities as a personal choice, and not a fixed characteristic, mobility across racial categories may play important roles in the growth of race/ethnic sub-populations and changes to the composition of the U.S. To examine this potential, we derive a reduced-form population balancing equation that treats fertility and international migration as given and estimates survival from period life table data. After subtracting out national increase and migration and adjusting the balance of observed growth for changes in racial measurement and census coverage, we argue that the remaining error of closure provides a reasonable estimate of net interracial mobility among the native born. Using recent Census and ACS microdata, we illustrate the impact that identity shifts may have had on the growth of race/ethnic sub-populations in the past quarter century. Findings suggest a small drift from the non-Hispanic white population into race/ethnic minority groups, though the pattern varies by age and between time periods.
Economic growth and emissions reconsidering the empirical basis of environmental Kuznets curves
International Nuclear Information System (INIS)
De Bruyn, S.M.; Van den Bergh, J.C.J.M.; Opschoor, J.B.
1998-01-01
Recent empirical research indicates that certain types of emissions follow an inverted-U or environmental Kuznets curve (EKC) as income grows. This regularity has been interpreted as a possible de-linking of economic growth and patterns of certain pollutants for developed economies. In this paper the empirical basis of this result is investigated, by considering some statistical particularities of the various EKC studies performed. It is argued that the inverted-U relationship between income and emissions estimated from panel data need not hold for specific individual countries over time. Based on insights from 'intensity-of-use' analysis in resource economics an alternative growth model is specified and estimated for three types of emissions (CO 2 , NO x and SO 2 ) in four countries (Netherlands, UK, USA and Western Germany). It is found that the time patterns of these emissions correlate positively with economic growth and that emission reductions may have been achieved as a result of structural and technological changes in the economy. 'Sustainable growth' is defined as the rate of economic growth that does not lead to growth in emissions. Its rate is calculated for each type of emission and country, based on estimated parameter values. The resulting indicators reflect a balance between the positive influence of growth and negative influence of structural change and technological progress on emission levels
The complexity of computing the MCD-estimator
DEFF Research Database (Denmark)
Bernholt, T.; Fischer, Paul
2004-01-01
In modem statistics the robust estimation of parameters is a central problem, i.e., an estimation that is not or only slightly affected by outliers in the data. The minimum covariance determinant (MCD) estimator (J. Amer. Statist. Assoc. 79 (1984) 871) is probably one of the most important robust...... estimators of location and scatter. The complexity of computing the MCD, however, was unknown and generally thought to be exponential even if the dimensionality of the data is fixed. Here we present a polynomial time algorithm for MCD for fixed dimension of the data. In contrast we show that computing...... the MCD-estimator is NP-hard if the dimension varies. (C) 2004 Elsevier B.V. All rights reserved....
Environmental Monitoring Plan for the Oak Ridge Reservation, 2012
Energy Technology Data Exchange (ETDEWEB)
Thompson, Sharon D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
2012-10-01
The purpose of Oak Ridge Reservation (ORR) environmental surveillance is to characterize radiological and nonradiological conditions of the off-site environs and estimate public doses related to these conditions, confirm estimations of public dose based on effluent monitoring data, and, where appropriate, provide supplemental data to support compliance monitoring for applicable environmental regulations. This environmental monitoring plan (EMP) is intended to document the rationale, frequency, parameters, and analytical methods for the ORR environmental surveillance program and provides information on ORR site characteristics, environmental pathways, dose assessment methods, and quality management. ORR-wide environmental monitoring activities include a variety of media including air, surface water, vegetation, biota, and wildlife. In addition to these activities, site-specific effluent, groundwater, and best management monitoring programs are conducted at the Oak Ridge National Laboratory (ORNL), the Y-12 National Security Complex (Y-12), and the East Tennessee Technology Park (ETTP). This is revision 5.
THE EUROPEAN CENTRAL BANK AND THE FEDERAL RESERVE: A COMPARATIVE ANALYSIS
Directory of Open Access Journals (Sweden)
Dorina Clichici
2017-06-01
Full Text Available The purpose of this article is to identify the main differences and similarities between the European Central Bank (ECB and US Federal Reserve (FED in terms of their functional framework and monetary policy. The research is based on a comparative analysis of the history of establishing the Eurosystem and the Federal Reserve System, which has influenced the way these central banks operate today. It also analyzes the policy responses of the two institutions to the 2007 global financial crisis, since both their non-conventional policy measures and the effects thereof on growth, inflation and unemployment rates were slightly different. The paper finds that there are differences between the ECB and FED rather regarding the organization and functioning of the Committees for monetary policy and monetary policy objectives than the institutional structure and policy framework
This report focuses on the methodology for estimating growth in NR engine populations as used in the MOVES201X-NONROAD emission inventory model. MOVES NR growth rates start with base year engine populations and estimate growth in the populations of NR engines, while applying cons...
A new approach for the analysis of facial growth and age estimation: Iris ratio
Machado, Carlos Eduardo Palhares; Flores, Marta Regina Pinheiro; Lima, Laíse Nascimento Correia; Tinoco, Rachel Lima Ribeiro; Bezerra, Ana Cristina Barreto; Evison, Martin Paul; Guimarães, Marco Aurélio
2017-01-01
The study of facial growth is explored in many fields of science, including anatomy, genetics, and forensics. In the field of forensics, it acts as a valuable tool for combating child pornography. The present research proposes a new method, based on relative measurements and fixed references of the human face—specifically considering measurements of the diameter of the iris (iris ratio)—for the analysis of facial growth in association with age in children and sub-adults. The experimental sample consisted of digital photographs of 1000 Brazilian subjects, aged between 6 and 22 years, distributed equally by sex and divided into five specific age groups (6, 10, 14, 18, and 22 year olds ± one month). The software package SAFF-2D® (Forensic Facial Analysis System, Brazilian Federal Police, Brazil) was used for positioning 11 landmarks on the images. Ten measurements were calculated and used as fixed references to evaluate the growth of the other measurements for each age group, as well the accumulated growth (6–22 years old). The Intraclass Correlation Coefficient (ICC) was applied for the evaluation of intra-examiner and inter-examiner reliability within a specific set of images. Pearson’s Correlation Coefficient was used to assess the association between each measurement taken and the respective age groups. ANOVA and Post-hoc Tukey tests were used to search for statistical differences between the age groups. The outcomes indicated that facial structures grow with different timing in children and adolescents. Moreover, the growth allometry expressed in this study may be used to understand what structures have more or less proportional variation in function for the age ranges studied. The diameter of the iris was found to be the most stable measurement compared to the others and represented the best cephalometric measurement as a fixed reference for facial growth ratios (or indices). The method described shows promising potential for forensic applications
A new approach for the analysis of facial growth and age estimation: Iris ratio.
Directory of Open Access Journals (Sweden)
Carlos Eduardo Palhares Machado
Full Text Available The study of facial growth is explored in many fields of science, including anatomy, genetics, and forensics. In the field of forensics, it acts as a valuable tool for combating child pornography. The present research proposes a new method, based on relative measurements and fixed references of the human face-specifically considering measurements of the diameter of the iris (iris ratio-for the analysis of facial growth in association with age in children and sub-adults. The experimental sample consisted of digital photographs of 1000 Brazilian subjects, aged between 6 and 22 years, distributed equally by sex and divided into five specific age groups (6, 10, 14, 18, and 22 year olds ± one month. The software package SAFF-2D® (Forensic Facial Analysis System, Brazilian Federal Police, Brazil was used for positioning 11 landmarks on the images. Ten measurements were calculated and used as fixed references to evaluate the growth of the other measurements for each age group, as well the accumulated growth (6-22 years old. The Intraclass Correlation Coefficient (ICC was applied for the evaluation of intra-examiner and inter-examiner reliability within a specific set of images. Pearson's Correlation Coefficient was used to assess the association between each measurement taken and the respective age groups. ANOVA and Post-hoc Tukey tests were used to search for statistical differences between the age groups. The outcomes indicated that facial structures grow with different timing in children and adolescents. Moreover, the growth allometry expressed in this study may be used to understand what structures have more or less proportional variation in function for the age ranges studied. The diameter of the iris was found to be the most stable measurement compared to the others and represented the best cephalometric measurement as a fixed reference for facial growth ratios (or indices. The method described shows promising potential for forensic