This paper examines the effects of oil price shocks on the real GDP of the Gulf Cooperation Council (GCC) countries. The empirical method used is the nonlinear cointegrating autoregressive ...distributed lag (NARDL) model of Shin et al. (2013) in which short-run and long-run nonlinearities are introduced via positive and negative partial sum decompositions of the explanatory variable(s). The results suggest evidence of asymmetries in all the cases. We find significant positive oil price changes in all the cases with the expected positive sign, implying that increases in oil price lead to increases in real GDP. Conversely, negative oil price changes are significant for only Kuwait and Qatar with the expected positive sign, suggesting that decreases in oil price lead to decreases in their real GDP. Further analysis implemented using panel data shows that positive oil prices changes increase real GDP and negative changes decrease real GDP. Overall, the results suggest that positive oil price changes have a considerably larger impact on real GDP than negative changes.
•We study the effects of oil price shocks on the real GDP of the GCC countries.•We use the nonlinear ARDL model and panel cointegration analysis.•Results suggest rising oil price increase real GDP and falling price lower real GDP.•Increasing oil prices have a considerably larger impact than falling prices.
This article describes a robust simultaneous joint inversion scheme for the interpretation of gravity and self-potential data measured along the profile. The developed scheme jointly inverts the two ...data sets of the causative targets by some geometrically simple idealized bodies (the so-called approximative/interpretive models) in the restricted class of spheres and cylinders. It simultaneously recovers the characteristic inverse parameters of all interpretive bodies (that is, the depth <inline-formula> <tex-math notation="LaTeX">z </tex-math></inline-formula>, amplitude coefficient <inline-formula> <tex-math notation="LaTeX">A </tex-math></inline-formula>, electric dipole moment <inline-formula> <tex-math notation="LaTeX">K </tex-math></inline-formula>, and polarization angle <inline-formula> <tex-math notation="LaTeX">\theta </tex-math></inline-formula> of each body). It employs the Gauss-Newton (GN) method in the space of the logarithmed and nonlogarithmed model parameters (<inline-formula> <tex-math notation="LaTeX">\log (|A|) </tex-math></inline-formula>, <inline-formula> <tex-math notation="LaTeX">\log (K) </tex-math></inline-formula>, <inline-formula> <tex-math notation="LaTeX">\theta </tex-math></inline-formula>, <inline-formula> <tex-math notation="LaTeX">\log (z) </tex-math></inline-formula> of each body) (rather than in the space of the model parameters themselves (<inline-formula> <tex-math notation="LaTeX">A </tex-math></inline-formula>, <inline-formula> <tex-math notation="LaTeX">K </tex-math></inline-formula>, <inline-formula> <tex-math notation="LaTeX">\theta </tex-math></inline-formula>, <inline-formula> <tex-math notation="LaTeX">z </tex-math></inline-formula>)) to maintain the convergence. The scheme has been successfully validated on a number of noise-free numerical examples, after which the accuracy and stability of the scheme have been carefully assessed on various noisy data. The influence of the scaling factors of the objective functional subjected to minimization on the convergence of the GN method and on the nonuniqueness of the approximative solution that describes and resembles the underlying buried targets has been investigated. It has been found that the developed scheme is very robust and capable of extracting accurate and useful information that is of some significance in mineral exploration. Finally, the scheme has been applied to a real data example from Germany. Careful analysis of this case study suggests new results that are of some value in mining geophysics.
This paper investigates the effects of oil price shocks on Asian exchange rates. We employ quantile regression analysis and allow for structural breaks and asymmetry. Our results indicate that ...positive and negative oil price shocks have asymmetrical effects on exchange rate returns that vary in significance, size, and sign throughout the distribution of exchange rate returns. The impact of oil price shocks is also affected by market conditions (bearish and bullish currency markets). During bullish markets in domestic currencies, (at lower quantiles of currency movements in terms of U.S. dollar exchange rates), rising oil prices cause further appreciation for Indonesia, Korea, the Philippines, and Thailand currencies. During bearish markets in the domestic currencies (at higher quantiles of exchange rate movements in terms of U.S. dollar exchange rates), rising (falling) oil price causes further currency depreciation for Indonesia (Malaysia). Thus, currencies respond differently to oil price shocks under extreme bullish or bearish currency market conditions and the impact of rising or falling oil prices on foreign exchange markets can vary by country and market conditions.
•We study the effects of oil price shocks on some Asian countries' real exchange rates.•We use quantile regression analysis and allow for structural breaks and asymmetries.•Results suggest that oil price shocks have asymmetrical effects on exchange rate returns.•The impact of oil price shocks is affected by market conditions.
•Natural Edible Films in Food Packaging.•Polysaccharide-Based Edible Films.•Animal, Plant and Marine origin polysaccharides.
Polysaccharides, such as pectin, starch, alginate, carrageenan, and ...xanthan gum, have been used as biopolymer materials to create coatings and edible films to reduce traditional plastic packages. Petrochemical polymers, extensively used for food packaging, are non-renewable and non-biodegradable and need landfills. Thus, there is a requirement to find alternative packaging materials that are easily degradable and renewable. Natural edible polymers are the materials made from natural edible constituents that can be consumed by animals or human beings with no health risk. Since they are directly consumed with food, nothing is left for disposal. Polysaccharides, Protein and Lipid-Based Natural edible polymers are used to make coatings and edible films surrounding the surface of the food. These natural edible polymers are generally categorized into polysaccharides, lipids and proteins. This review article summarizes the importance of various natural polymers used for making coatings and edible films.
A nonlinear optimization algorithm has been described for the inversion of gravity data profile by a faulted 2-D horizontal thin block. The algorithm simultaneously optimizes for the depth to the ...center (<inline-formula> <tex-math notation="LaTeX">z </tex-math></inline-formula>) of the faulted block, the amount and direction of dip (<inline-formula> <tex-math notation="LaTeX">\theta </tex-math></inline-formula>) of the fault plane, and the amplitude coefficient (<inline-formula> <tex-math notation="LaTeX">A </tex-math></inline-formula>), which is dependent on the amount of throw <inline-formula> <tex-math notation="LaTeX">t </tex-math></inline-formula> and the density contrast <inline-formula> <tex-math notation="LaTeX">\Delta \rho </tex-math></inline-formula> of the block. The objective functional of this algorithm coupled with both the space of logarithmed absolute values of the observed and predicted gravity data and the space of logarithmed <inline-formula> <tex-math notation="LaTeX">\log (z) </tex-math></inline-formula>, <inline-formula> <tex-math notation="LaTeX">\log (|A|) </tex-math></inline-formula>, and <inline-formula> <tex-math notation="LaTeX">\log (\theta </tex-math></inline-formula>) model parameters is the basis of the new inversion scheme introduced here. It has been found essential that the objective functional of this scheme be formulated in this particular combination so that the iterative solver/minimizer (the Gauss-Newton (GN) method) can converge. The developed scheme has been successfully verified on numerical models without noise and achieved superior convergence. It is found stable and can determine the inverse parameters of the faulted block with acceptable accuracy when applied to data contaminated with insignificant noise levels and/or geologic interference. In order to investigate the usefulness of the developed scheme, a published gravity profile has been inverted and analyzed, suggesting new results that are of some geologic significance. The computational efficiency, thorough analysis of the investigated numerical examples, and comparisons of the real data inverted in this paper have demonstrated that the scheme developed here is advantageous to the existing gravity data inversion schemes that solve for the characteristic inverse parameters of a faulted thin block.
This paper employs the linear autoregressive distributed lag (ARDL) model, the asymmetric nonlinear ARDL model, and the Pooled Mean Group (PMG) method to examine the symmetric and asymmetric effects ...of oil price changes on inflation in the Gulf Cooperation Council (GCC) countries. Short-run and long-run asymmetries are introduced via positive and negative partial sum decompositions of oil price. The results suggest that the variables are cointegrated and that there is significant evidence of long-run asymmetry. This implies that rising and falling oil prices have different effects on inflation. In particular, while rising oil price has a significant positive effect on inflation in all the cases, falling oil price is either insignificant or has a negative effect on inflation. The PMG model indicates that only rising oil price has a positive significant effect on inflation. Moreover, the results suggest that positive oil price changes have a larger impact than the negative ones, that the effect of an oil price shock is larger in the long-run than in the short-run, and that there is incomplete pass-through effect of oil price on domestic inflation.
•We study the effects of oil price changes on inflation in the GCC countries.•We use linear and nonlinear ARDL models and panel cointegration models.•Results suggest significant long-run asymmetry for rising and falling oil price.•Rising oil price has significant positive effects on inflation.•Falling oil price is either insignificant or has significant negative effects on inflation.
This article examines the J-curve phenomenon for 16 European transition economies. While previous studies assume a linear relationship between the exchange rate and the trade balance, this paper ...allows for nonlinearity. Following Bahmani-Oskooee and Fariditavana (
2015
,
2016
), the empirical method used is the nonlinear cointegrating autoregressive distributed lag (NARDL) model of Shin et al. (
2013
) in which short-run and long-run nonlinearities are introduced via positive (appreciation) and negative (depreciation) partial sum decompositions of the real exchange rate. We argue that the lack of support for the J-curve phenomenon could be due to the linearity assumption. This issue is examined by utilizing the linear and the NARDL models. Using the linear autoregressive distributed lag (ARDL) model, we are unable to find support for the J-curve phenomenon in any case. However, when the NARDL model is used, we are able to find evidence for the J-curve in 12 out of the 16 countries. This suggests that allowing for nonlinearity in the adjustment process is important when studying the J-curve phenomenon.
Introduction/Aim
Amyotrophic lateral sclerosis (ALS) is a degenerative neuromuscular disease with marked clinical heterogeneity. This heterogeneity can be partly captured by clinical measures, such ...as the forced vital capacity (FVC) and ALS Functional Rating Scale‐Revised (ALSFRS‐R). We aimed to further characterize the performance of these clinical measures, including their independence and additivity, in predicting mortality.
Methods
We leveraged the Pooled Resource Open‐Access ALS Clinical Trials (PRO‐ACT ALS) database, which includes data from 23 clinical trials (n = 2050). The primary exposures were baseline FVC and ALSFRS‐R. The primary outcome was 1‐y mortality. We performed correlation analyses, survival analyses and assessed classification performance using receiver operator characteristic (ROC) curves.
Results
FVC and ALSFRS‐R were weakly correlated (r = 0.31, p < .001). A 1‐SD increase in FVC (hazard ratio HR: 0.66; 95% confidence interval CI: 0.59–0.74) and ALSFRS‐R (HR: 0.75; 95% CI: 0.68–0.82) were associated with reduced risk of 1‐y mortality. ROC analyses showed optimal predictive cutoffs at 80% for FVC (area under the curve AUC: 0.69) and 38 for ALSFRS‐R (AUC: 0.67). After stratifying patients based on these cutoffs, we found a marked reduction (HR: 0.25; 95% CI: 0.19–0.33) in incident mortality for patients in the high FVC and high ALSFRS‐R group relative to the low FVC and low ALSFRS‐R group.
Discussion
ALSFRS‐R and FVC are comparable predictors of survival that are only weakly correlated. When considered together, they synergistically predict survival. As such, consideration of both measures should be a routine part of prognostication in care of patients with ALS.
We study the asymmetric effects of oil price changes on the domestic output of the ASEAN-5 countries (Indonesia, Malaysia. Singapore, Philippines, and Thailand) plus Japan and Korea. Asymmetries are ...introduced by accumulating oil price increases separately from decreases using partial sum processes in a nonlinear ARDL framework. Utilizing annual data for the period 1973–2018, the results from the linear ARDL model suggest that oil price changes do not affect the domestic output of Indonesia, Korea, Singapore, and Thailand. However, the nonlinear ARDL model reveals that oil price changes asymmetrically affect the domestic output of all seven Asian countries in both the short-run and in the long-run. We observe an asymmetrically larger effect on output from rising oil prices than from falling prices, but effects vary across countries. Moreover, nonlinear causality tests confirm causality from oil price to output in all the countries.
•We study the asymmetric effects of oil price changes on output.•We use linear and nonlinear ARDL models.•Results suggest significant asymmetries in most of the cases.•Results confirm causal relationship from oil price to output in most of the countries.
Rosetta ilmenite concentrate has been applied for uranium adsorption from its aqueous solution using batch sorption techniques. The optimised adsorption conditions included, solution pH 5, adsorbent ...dose (0.025 g/25 ml), uranium initial concentration 200 mg/L, 1 h contact time, and at room temperature (25°C), corresponding to uranium adsorption efficiency of about 74% and uranium uptake 148 mg/g. From kinetic parameters, it was found that uranium adsorption followed pseudo second order kinetics. Besides, the equilibrium data fitted the Langmuir isotherm model well. The various thermodynamic parameter rs were calculated (∆H
o
= −14.3 kJ mol
−1
, ∆S
o
= 0.075 kJ mol
−1
K
−1
, ∆G
o
= −36.65 kJ mol
−1
), these values an exothermic, randomness, and spontaneous adsorption process, respectively. Uranium is successfully desorbed from loaded ilmenite using 0.5 M H
2
SO
4
for 15 min. contact time.
