Estimation Of Different Components Research Articles

Heterogeneity in glacio-hydrological processes and estimation of different components in streamflow from central Himalayan glaciers

Study regionThe study region includes two glaciers from Alaknanda and Bhagirathi river basins in Central Himalaya. Study focusThe study focuses on the analysis of high-resolution isotopic data sets of different components of the streamflow with ground-based meteorological observations from Automatic Weather Stations (AWSs) at two glaciers (∼4000 m asl). New hydrological insights for the regionThe glaciers in the Himalaya are difficult to access due to their topography and climate and require complicated logistics to work in the region. Hence, the understanding of hydrological processes in this region is limited. The debris cover (sublimation of surface ice), orientation and microclimatic conditions (temperature, wind and rain) of the two glaciers control the isotope signatures of the glacier surface ice in the Himalayan region, indicating heterogeneity and complexity in the isotopic compositions. The studies estimating the contribution of different components to the streamflow downstream using generalized values of stable isotopes (glacier ice, snow) are complicated, as several glaciers contribute to the total runoff in large basins. The stable isotopes of streamflow indicate the contribution of snow and ice melt during early ablation (May-Jun.); rainfall and ice melt during the ISM (Jul.-Aug.) and ice melt during late ablation (Sep.-Oct.). The contribution of snow-glacier melt and rainfall for the ablation season (Jun.-Oct.) was 89% and 11%, respectively. The separation of the hydrograph is complex, site and time-specific, which needs attention.

Development and validation of HPLC method for simultaneous determination of Leflunomide and folic acid in the nanoparticulate system by reversed-phase HPLC

Objective The main objective of this study was to develop a highly sensitive, accurate, and reproducible analytical method for the simultaneous detection of LEF and FA in polymeric nanocarriers. Significance Leflunomide (LEF), is widely employed in the treatment of rheumatoid arthritis (RA). However, long-term delivery of the drug is associated with systemic side effects. Therefore, folate (FA) conjugated LEF nanocarriers were fabricated for targeting the nanocarriers toward activated macrophages. HPLC is considered one of the most sensitive and precise analytical techniques for the simultaneous detection and estimation of different components in a particular sample. Methods Analysis was performed on HPLC (Shimadzu 10 A), having a reversed-phase C-18 column (Beckmen, 250 X 4.6 mm, 5 µm) equipped with a photodiode detector set at a wavelength of 260 nm (LEF) and 285 nm (Folic acid). The isocratic mobile phase was composed of acetonitrile, water, and trimethylamine in a ratio of 65:35:0.5 at pH 4. Rapid analysis of both agents was performed, with a total run time of 10 min (FA = 2.1 ± 0.1 min, LEF = 5.9 ± 1 min) at a 1 mL/min flow rate. Results The assay demonstrated good linearity of 0.9989 of 0.9997 for LEF and FA respectively with a recovery in the range of 95–100%. The method also depicted good specificity, and intra and inter-day precision based on relative standard deviation (RSD) values. Conclusions The study concludes, that the developed method was helpful in the detection and quantitation of lower values of both agents from polymeric nanocarriers.

A reality check on the GARCH-MIDAS volatility models

We employ a battery of model evaluation tests for a broad set of GARCH-MIDAS models and account for data snooping bias. We document that inferences based on standard tests for GM variance components can be misleading. Our data mining free results show that the gain of macro-variables in forecasting total (long-run) variance by GM models is overstated (understated). Estimation of different components of volatility is crucial for designing differentiated investing strategies, risk management plans and pricing derivative securities. Therefore, researchers and practitioners should be wary of data-mining bias, which may contaminate a forecast that may appear statistically validated using robust evaluation tests.

Estimation of Water Footprint Components of Iran’s Wheat Production: Comparison of Global and National Scale Estimates

The water footprint (WF) of national wheat production has been previously estimated for the whole world in global-scale studies. These studies used assumptions which must be assessed and evaluated by estimates from national or regional studies. Here, previous estimates of different components (green, blue, gray and white) of WF of national wheat production in Iran were compared to the national-scale estimates. A new component (white WF) was proposed to account for the irrigation losses. Different components of the wheat WF were estimated for 236 plains over fifteen major wheat producing provinces. Then, the average values of each province were estimated. Finally, the weighted average values of each WF component were estimated by using the shares of irrigated and rainfed productions as weighting factors. The average total WF for irrigated areas and between all selected provinces is about 3,188 m3/ton with comparable shares of blue and green water, while the average total WF for rainfed areas is about 3,071 m3/ton with the share of the green WF nine times that of the gray WF. The results show that the total national WF of wheat production for the period 2006–2012 is about 42,143 million cubic meters (MCM) per year (41 % green, 18 % blue, 16 % gray and 25 % white) with the share of the green WF about 2.3 times the blue WF. Comparison of the obtained estimates with the results of the previous studies at a global scale revealed that estimating the WFs of crops at a global scale, ignores the variations of climatic conditions, water resources availability and crop yields at the national and regional levels and some of the assumptions made in global-scale studies must be reassessed.

Partitioning Of Energy Balance Components at Different Phenological Stages of Wheat

A thorough understanding of the radiation balance over a crop canopy and the accurate estimation of different components of net radiation over the crop surface assume a great significance in terrestrial ecosystem. Considering its importance a field experiment was conducted at agricultural farm of GBPUA&T Pantnagar during rabi season of 2012-13 to estimate partitioning of energy balance components by using Bowen Ratio Energy Balance (BREB) method at different phenological stages of wheat. The BREB method was used to obtain field energy balance, including latent heat flux, soil heat flux. These measurements were coupled with radiation measurement at the soil surface to partition energy balance component at different phenological stages of wheat viz. Crown root initiation (CRI), tillering, jointing, heading, flowering, grain filling, soft dough and hard dough stage .It was found that net radiation (Rn) was the major portion of energy balance component. The values varied between 6.02 to 27.6 MJm -2 d -1 at various growth stages of wheat crop. Similarly, latent heat flux (LE) ranged between 2.11 to 12.79 MJm -2 d -1 during the crop season. In the present study in different phenological stages of wheat, latent heat flux varied between 3.59 to 15.25 MJm -2 d -1 . The ground heat flux varied from 0.31 to 0.88 MJm -2 d -1 in different stages. The peak midday ground heat flux decreased gradually from crown root initiation to soft dough stage because of increasing soil coverage. It can be concluded from the present study that Bowen ratio approach is an efficient technique of measurement of energy balance. This method, as applied, can accurately estimate energy balance component for wheat crop in Tarai region of Uttarakhand. Key word: Latent heat flux(LE), Phenological stages, Crown root initiation, Net radiation, Soft dough stage, BREB method I. Introduction Radiation and latent and sensible heating are among the most important processes in land-atmosphere exchanges. Hence, quantitative understanding and accurate estimation of these fluxes at large scales are imperative for research and applications in areas ranging from climate research, water cycle study, to water resources management, sustainable agricultural production and ecological conservation. The quantity and the form of energy available in a system determine the efficiency of the system. Available net radiation is the main source of energy in the earth system. Total energy available over a crop surface and partitioning of this into different components such as sensible heat (H), latent (LE) and soil heat fluxes (G) determine the crop production. Therefore, a thorough understanding of the radiation balance over a crop canopy and the accurate estimation of different components of net radiation over the crop surface assume a great significance in terrestrial ecosystem. The components of energy balance are calculated with the of help Bowen-ratio energy balance method and energy balance equation (Rn+ H +LE +G+PS+M =0). `

К вопросу о мотивации в профессиональном становлении студента

In the article the analysis of intercommunication between the estimation of different components of institution of higher learning environment is presented and by the estimation of professionally‑ personality height of students. Two strategies of the professional becoming of students are educed with different motivation.

Evolution of reproductive isolation in plants

Reproductive isolation is essential for the process of speciation and much has been learned in recent years about the ecology and underlying genetics of reproductive barriers. But plant species are typically isolated not by a single factor, but by a large number of different pre- and postzygotic barriers, and their potentially complex interactions. This phenomenon has often been ignored to date. Recent studies of the relative importance of different isolating barriers between plant species pairs concluded that prezygotic isolation is much stronger than postzygotic isolation. But studies of the patterns of reproductive isolation in plants did not find that prezygotic isolation evolves faster than postzygotic isolation, in contrast to most animals. This may be due to the multiple premating barriers that isolate most species pairs, some of which may be controlled by few genes of major effect and evolve rapidly, whereas others have a complex genetic architecture and evolve more slowly. Intrinsic postzygotic isolation in plants is correlated with genetic divergence, but some instrinsic postzygotic barriers evolve rapidly and are polymorphic within species. Extrinsic postzygotic barriers are rarely included in estimates of different components of reproductive isolation. Much remains to be learned about ecological and molecular interactions among isolating barriers. The role of reinforcement and reproductive character displacement in the evolution of premating barriers is an open topic that deserves further study. At the molecular level, chromosomal and genic isolation factors may be associated and act in concert to mediate reproductive isolation, but their interactions are only starting to be explored.

Evaluation of approaches to estimating aboveground biomass in Southern pine forests using SIR-C data

A study was performed to evaluate various techniques for estimating aboveground, woody plant biomass in pine stands found in the southeastern United States, using C- and L- band multiple polarization radar imagery collected by the Shuttle Imaging Radar-C (SIR-C) system. The biomass levels present in the test stands ranged between 0.0 and, 44.5 kg m −2. Two SIR-C data sets were used: one collected in April, 1994, when the soil conditions were very wet and the canopy was slightly wet from dew and a second collected in October, 1994, when the soils and canopy were dry. During the October mission, pine needles were completely flushed and the foliar biomass was twice as great in the forest stands as in April. Four methods were evaluated to estimate total biomass: one including a straight multiple linear correlation between total biomass and the various SIR-C channels; another including a ratio of the L-band HV/C-band HV channels; and two others requiring multiple steps, where linear regression equations for different stand components (height, basal area, and crown or branch biomass) were used as the basis for estimating total biomass. It was shown that the data collected in October (dry soil conditions) were better for estimation of biomass than the data collected in April (wet soil conditions). Overall, a multistep approach resulted in the lowest root mean square (RMS) errors (5.91 kg m −2) when biomass levels were <20 kg m −2. For all biomass levels, the simple regression technique resulted in the lowest RMS errors (8.1 kg m −2). The multiple-step approaches have the additional advantage of being able to provide estimates of different components of stand structure and biomass, such as average tree height, basal area, branch biomass, canopy biomass, trunk biomass, and foliage biomass. The LHV channel is the critical element in all the biomass equations, as would be expected from the body of literature. The addition of other channels—generally, CHV or CHH—significantly improves biomass estimates, whether as a ratio or as additional terms in a regression equation.

Current Strategies for Cancer Prevention: Chemoprevention

Observations at ecological level show strong correlation between exogenous exposures, such as fat consumption, and risk of cancers. The correlations are less but significant at an individual level between many dietary items and cancer risk based on case-control and cohort studies. Most specific attempts to evaluate the role of diet on cancer risk stems from use of serum sample banks and estimation of different components of biochemistry in cases of cancer and healthy controls. The extension of this vast amount of epidemiological knowledge has resulted in preventive trials, chemoprevention of cancer, and in routine use of preventive substances, vitamins and minerals. However, the trials are relatively few and even less frequent are those with invasive cancer as end point. Furthermore, the results of these trials have been rather negative, and it seems at present that vitamins and minerals videly used in adult age for chemopreventive purposes are relative ineffective to prevent occurrence of invasive cancer or death from cancer. This does not imply that these chemical substances were not causes of cancer.J Epidemiol, 1996 ; 6 : S39-S42.

Microscopic analyses of antiproton scattering in the analytic distorted wave approximation

An analytic representation of the conventional distorted wave approximation is employed in studies of elastic and inelastic scattering of low-energy (46.8 MeV) antiprotons. Several sets of optical model parameters are used to ascertain the appropriate analytic function form and to adequately account for the predominant effects of the annihilation potential. The inelastic scattering calculations are performed with a one-boson-exchange antinucleon-nucleon force containing central, tensor, spin-orbit and quadratic spin-orbit characteristics. Good fits to the existing elastic and inelastic [2 1 +(4.44 MeV) state in 12C] scattering data are obtained and predictions for inelastic scattering leading to several other states in 12C are also presented to show that such data analyses facilitate comparisons of (large basis) nuclear spectroscopies and selective estimates of different components in the N̄N interaction.