Miracle-dz/UniFAR-FTUs huggingface dataset:
Simple kinematic models for the environmental interaction of tropical cyclones in vertical wind shear

Abstract. A major impediment to the intensity forecast of tropical cyclones (TCs) is believed to be associated with the interaction of TCs with dry environmental air. However, the conditions under which pronounced TC-environment interaction takes place are not well understood. As a step towards improving our understanding of this problem, we analyze here the flow topology of a TC immersed in an environment of vertical wind shear in an idealized, three-dimensional, convection-permitting numerical experiment. A set of distinct streamlines, the so-called manifolds, can be identified under the assumptions of steady and layer-wise horizontal flow. The manifolds are shown to divide the flow around the TC into distinct regions. The manifold structure in our numerical experiment is more complex than the well-known manifold structure of a non-divergent point vortex in uniform background flow. In particular, one manifold spirals inwards and ends in a limit cycle, a meso-scale dividing streamline encompassing the eyewall above the layer of strong inflow associated with surface friction and below the outflow layer in the upper troposphere. From the perspective of a steady and layer-wise horizontal flow model, the eyewall is well protected from the intrusion of environmental air. In order for the environmental air to intrude into the inner-core convection, time-dependent and/or vertical motions, which are prevalent in the TC inner-core, are necessary. Air with the highest values of moist-entropy resides within the limit cycle. This "moist envelope" is distorted considerably by the imposed vertical wind shear, and the shape of the moist envelope is closely related to the shape of the limit cycle. In a first approximation, the distribution of high- and low-θe air around the TC at low to mid-levels is governed by the stirring of convectively modified air by the steady, horizontal flow. Motivated by the results from the idealized numerical experiment, an analogue model based on a weakly divergent point vortex in background flow is formulated. The simple kinematic model captures the essence of many salient features of the manifold structure in the numerical experiment. A regime diagram representing realistic values of TC intensity and vertical wind shear can be constructed for the point-vortex model. The results indicate distinct scenarios of environmental interaction depending on the ratio of storm intensity and vertical-shear magnitude. Further implications of the new results derived from the manifold analysis for TCs in the real atmosphere are discussed.
IMPACT OF URBAN EXPANSION ON SURFACE TEMPERATURE IN BAGHDAD, IRAQ USING REMOTE SENSING AND GIS TECHNIQUES

Baghdad city has experienced a rapid urban expansion over the last decades due to accelerated economic growth. This paper reports an investigation into the application of the integration of remote sensing and geographic information systems (GIS) for detecting urban built up growth for the period 1961-2002, and evaluate its impact on surface temperature in Baghdad city. The purpose of this study is to analysis and verifies the spatial distribution property of the surface temperature with urban spatial information, related with land cover / land use and NDVI using remotely sensed data and GIS. Surface temperature, land cover pattern and NDVI were extracted from Landsat7 ETM + data. Then surface temperatures, was linked to land use data of Baghdad region for further investigations of the relationship between temperature behavior and urban structures. The Normalized Difference Vegetation Index (NDVI) was used to examine the relation between thermal behavior and vegetation cover amount. The results showed that the negative average correlation more than 85 % was identified by the results from the correlation and regression analysis of the extracted surface temperature from Landsat data image with NDVI. Also this research verified the distribution of urban surface temperature was very different depends on various land cover type of surrounding areas. Water and forest cover types show low day temperature differences compared to residential, commercial cover types. The integration of remote sensing and GIS was found to be effective in monitoring and analyzing urban growth patterns and in evaluating urbanization impact on surface temperature.
Energetics of the Kelvin-Helmholtz instability induced by transverse waves in twisted coronal loops

Aims. We quantify the effects of twisted magnetic fields on the development of the magnetic Kelvin-Helmholtz instability (KHI) in transversely oscillating coronal loops. Methods. We modelled a fundamental standing kink mode in a straight, density-enhanced magnetic flux tube using the magnetohydrodynamics code, Lare3d. In order to evaluate the impact of an azimuthal component of the magnetic field, various degrees of twist were included within the flux tube’s magnetic field. Results. The process of resonant absorption is only weakly affected by the presence of a twisted magnetic field. However, the subsequent evolution of the KHI is sensitive to the strength of the azimuthal component of the field. Increased twist values inhibit the deformation of the loop’s density profile, which is associated with the growth of the instability. Despite this, much smaller scales in the magnetic field are generated when there is a non-zero azimuthal component present. Hence, the instability is more energetic in cases with (even weakly) twisted fields. Field aligned flows at the loop apex are established in a twisted regime once the instability has formed. Further, in the straight field case, there is no net vertical component of vorticity when integrated across the loop. However, the inclusion of azimuthal magnetic field generates a preferred direction for the vorticity which oscillates during the kink mode. Conclusions. The KHI may have implications for wave heating in the solar atmosphere due to the creation of small length scales and the generation of a turbulent regime. Whilst magnetic twist does suppress the development of the vortices associated with the instability, the formation of the KHI in a twisted regime will be accompanied by greater Ohmic dissipation due to the larger currents that are produced, even if only weak twist is present. The presence of magnetic twist will likely make the instability more difficult to detect in the corona, but will enhance its contribution to heating the solar atmosphere. Further, the development of velocities along the loop may have observational applications for inferring the presence of magnetic twist within coronal structures.
Efficient Estimation of Approximate Factor Models

We study the estimation of a high dimensional approximate factor model in the presence of both cross sectional dependence and heteroskedasticity. The classical method of principal components analysis (PCA) does not efficiently estimate the factor loadings or common factors because it essentially treats the idiosyncratic error to be homoskedastic and cross sectionally uncorrelated. For the efficient estimation, it is essential to estimate a large error covariance matrix. We assume the model to be conditionally sparse, and propose two approaches to estimating the common factors and factor loadings; both are based on maximizing a Gaussian quasi-likelihood and involve regularizing a large covariance sparse matrix. In the first approach the factor loadings and the error covariance are estimated separately while in the second approach they are estimated jointly. Extensive asymptotic analysis has been carried out. In particular, we develop the inferential theory for the two-step estimation. Because the proposed approaches take into account the large error covariance matrix, they produce more efficient estimators than the classical PCA methods or methods based on a strict factor model.
Extending the Determinants of Dollarization in Sub-Saharan Africa: The Role of Easy Access to Foreign Exchange Earnings

This study argues that the ease at which economic agents have access to foreign earnings would influence/increase the level of dollarization in the economy. The three sources of foreign currency earnings are financial integration, trade openness and natural resource rent. As such, we extend the determinants of dollarization to capture these variables. A dataset of 26 countries in sub-Saharan Africa (SSA) for the period 2001 – 2012 was built. Based on Tobit regression, we found that all the proxies of foreign currency earning, with the exception of natural resource rent, are significant contributors to the increasing rate of dollarization. Specifically, it was found that trade openness and financial liberalization are positive determinants of dollarization, while natural resource rent serves as drag to the dollarization process. These results remain valid to three robustness tests. Policy implications and suggestions for future research were proposed.
Study on the Shock-transmission Mechanism of Stock Price among China, Russia and India

Researchers pay more and more attention on the price comovement-effect among international stock markets. This paper deals with the transmission mechanism of price shocks among three stock markets of China, Russia and India, with a sample of weekly returns. The results showed that the price fluctuation of each market has an influence on other markets, although the price behavior is significantly independent. The impact of external price innovations will last 5 or 6 weeks usually and disappear after about 8 weeks. The pattern of transmission-mechanism for the price shocks is very different from each other. Besides, a further study revealed that the influence of external shocks on the domestic stock price increased significantly among the three markets after the 2008 international financial crisis.
The producer welfare effects of trade liberalization when goods are perishable and habit-forming: the case of asparagus

Asparagus is a perishable, highly seasonal crop. We find that out-of-season imports of asparagus caused habit formation that increased demand in the U.S. growing seasons. We find that habit effects offset about 64% of the welfare losses to U.S. asparagus producers from increased Mexican imports under NAFTA and all of the U.S. producer welfare losses from increased Peruvian imports under the Andean Trade Preference Act. We estimate that the U.S. producer welfare losses from NAFTA are less than the annualized value of market loss assistance provided them in the 2008 Farm Bill.
Interannual variation of northeast monsoon rainfall over southern peninsular India

Area average rainfall of southern peninsular India is calculated for northeast monsoon season from daily gridded data. Years of strong and weak northeast monsoon were identified. Sea level pressure (SLP), sea surface temperature (SST), and 850 h Pa zonal wind are analyzed for years of strong and weak northeast monsoon rainfall. Difference between years of strong and weak rainfall of northeast monsoon high pressure anomaly over west pacific region near Philippines, low pressure over west Indian Ocean including Arabian sea, high SST anomaly over equatorial Pacific and Bay of Bengal. Among these the Sea level Pressure difference (SPD) between west pacific and west Indian ocean plays the key role in determining the strength of northeast monsoon rainfall over southern peninsular India.
THE ANTI–ANGIOGENIC ACTIVITY OF PHOENIX DACTYLIFERA SEEDS EXTRACTS

Objective: To identify the possible anti–angiogenic activity of Phoenix dactylifera seeds extract. Methods: The powder of the date palm seeds was extracted sequentially with petroleum ether, chloroform, methanol and water using the cold method "maceration" as extraction process. The ex vivo rat aorta ring assay was used to screen the extracts for possible anti–angiogenesis activity, this assay was also used to determine the dose–response effect of the active extract(s) by preparing serial concentrations. Free radical scavenging activity of the active extract(s) was determined using DPPH (1, 1–diphenyl–2–picrylhydrazyl) assay. Results: The obtained data revealed that the four extracts exhibited significant inhibition of blood vessels growth when they were compared to the negative control (received DMSO 1%) (P<0.001), but chloroform and methanol extracts showed the highest percent of inhibition of blood vessels growth. According to the screening results, both chloroform and methanol extracts were selected for further investigation. Each of chloroform and methanol extracts of Phoenix dactylifera seeds exhibited a significant dose–dependent anti–angiogenesis effect with IC 50 (30.9 µg/ml and 28.4 µg/ml) respectively. Furthermore, chloroform and methanol extracts exhibited a significant free radical scavenging activity (P<0.05) with IC 50 (81.02 µg/ml and 16.33 µg/ml) respectively. Conclusion: the results revealed that each of chloroform and methanol extracts of phoenix dactylifere seeds exhibited the best and most significant anti–angiogenesis activity as well as a significant free radical scavenging activity.
Relative Advantages: Casual Employment and Casualisation in Australia and New Zealand

Australia and New Zealand share a common experience of casual work. In both countries a category of 'casual' has long been permitted under labour regulation, and in both countries this has been associated with concerns about precariousness in employment. At least up until the recent period, labour regulation in both countries sought to limit casual employment in similar ways through quantitative restrictions and through prescription of a 'casual loading' on the hourly rate of pay. Yet, in spite of these strong parallels, casual employment seems less significant in New Zealand as a proportion of the total workforce and it seems to lack the same pace of growth as in Australia. This article asks why there should be this difference. It sketches out an answer that focuses on employer calculations and choices (within the framework of labour regulation, including custom and practice). We suggest that the relative advantages of casual employment to employers are narrower and less imposing in New Zealand. We warn that this cannot be taken as a source of comfort about the better quality of work in New Zealand. The compression of relative advantages is partly because of the greater access of casual employees to standard rights or benefits but it is also partly because of the poorer conditions of permanent workers.
A cyclone climatology of the British‐Irish Isles 1871–2012

The British‐Irish Isles (BI) lie beneath the North Atlantic storm track year‐round and thus are impacted by the passage of extra‐tropical cyclones. Given recent extreme storminess and projections of enhanced winter cyclone activity for this region, there is much interest in assessing the extent to which the cyclone climate of the region may be changing. We address this by assessing a 142‐year (1871–2012) record of cyclone frequency, intensity and ‘storminess’ derived from the 20th Century Reanalysis V2 (20CR) dataset. We also use this long‐term record to examine associations between cyclone activity and regional hydroclimate. Our results confirm the importance of cyclone frequency in driving seasonal precipitation totals which we find to be greatest during summer months. Cyclone frequency and storminess are characterized by pronounced interannual and multi‐decadal variability which are strongly coupled to atmospheric blocking in the Euro‐Atlantic region, but we detect no evidence of an increasing trend. We observe an upward trend in cyclone intensity for the BI region, which is strongest in winter and consistent with model projections, but promote caution interpreting this given the changing data quality in the 20CR over time. Nonetheless, we assert that long‐term reconstruction is helpful for contextualizing recent storminess and for identifying emerging changes in regional hydroclimate linked to cyclones.
The impact of HIV on children's welfare

Children living in HIV/AIDS affected households bear the heaviest burden of the epidemic. Besides direct vertical transmission, HIV/ AIDS potentially worsens the children’s welfare indirectly through its socio-economic impact. This paper uses household survey data including information about individual HIV infection status to analyze the direct and indirect effects of HIV-infected household members on child mortality, undernutrition and educational attainment for Burkina Faso, Cameroon, Ghana and Kenya. The results indicate that the main channel through which HIV effects the child mortality risk is mother to child transmission. Whereas no effect of HIV is found on child mortality and undernutrition, a negative effect for school enrollment is found for Burkina Faso and Cameroon.
Influence of selected Eulerian Multiphase Model parameters on the simulation results for a spouted bed grain dryer

The results of a numerical simulation of a spouted bed grain dryer based on the Eulerian Multiphase Model are presented. The influence of various model parameters on the height of the fountain forming in the drying chamber was analyzed. The following computer model parameters were considered: air inlet velocity, grain size and density, and the lowering of bed surface resulting from drying shrinkage and grain pack. An analysis of the approach of turbulence modeling of similar systems is included. The number of computation dimensions and numerical grids is discussed. The presented studies are based on earlier experiments conducted at a dedicated experimental station. Their main objective was to determine the basic principles of modeling fluidized beds found in grain dryers and the computer model’s sensitivity to changes in its basic parameters.
Using text-mining-assisted analysis to examine the applicability of unstructured data in the context of customer complaint management

In quest of gaining a more holistic picture of customer experiences, many companies are starting to consider textual data due to the richer insights on customer experience touch points it can provide. Meanwhile, recent trends point towards an emerging integration of customer relationship management and customer experience management and thereby availability of additional sources of textual data. Using text-mining-assisted analysis, this study demonstrates the practicality of the arising opportunity with means of perceived justice theory in the context of customer complaint management. The study shows that customers value interpersonal aspects most as part of the overall complaint handling process. The results link the individual factors in a sequence of ‘courtesy → interactional justice → satisfaction with complaint handling’, followed by behavioural outcomes. Academic and managerial implications are discussed.
Evaluation of the Computerized Strategic Reading Program applied to Elementary School Students 1

: Nationwide studies and evaluations performed in Brazil have shown that most elementary education students have difficulties in reading comprehension, despite the fact it is a skill that is essential for academic success. This study evaluates a Computerized Strategic Reading Program ( Programa Informatizado de Leitura Estratégica - PILE) intended to improve reading comprehension of elementary school students. A total of 58 students attending from the 5 th to 8 th grades, with a mean age of 12.52 years, participated: 29 comprised the control group (CG) and 29 comprised the intervention group (IG). A Cloze test was used pre-and post-measurement. The PILE was administered for six weeks, totaling 19 meetings. There was significant improvement from the pre-to the post-measurements for levels of reading comprehension in both the IG and the CG. The IG experienced a greater impact from the intervention, suggesting that PILE was effective in improving reading comprehension among these students.
Estimation and Inference in Nonparametric Frontier Models: Recent Developments and Perspectives

Nonparametric estimators are widely used to estimate the productive efficiency of firms and other organizations, but often without any attempt to make statistical inference. Recent work has provided statistical properties of these estimators as well as methods for making statistical inference, and a link between frontier estimation and extreme value theory has been established. New estimators that avoid many of the problems inherent with traditional efficiency estimators have also been developed; these new estimators are robust with respect to outliers and avoid the well-known curse of dimensionality. Statistical properties, including asymptotic distributions, of the new estimators have been uncovered. Finally, several approaches exist for introducing environmental variables into production models; both two-stage approaches, in which estimated efficiencies are regressed on environmental variables, and conditional efficiency measures, as well as the underlying assumptions required for either approach, are examined.
Organizational Learning as Moderating Variable Between Human Resource Information System and Public Universities’ Performance

This study was conducted to see if organizational performance is affected by human resource information system (HRIS) and organizational learning capability. HRIS examined in this study consists of performance appraisal and career management. Data were collected at the public universities located in West Sumatra using questionnaires as the main data collection tool in quantitative approach. Data were analysed using the Statistical Program for Social Science (SPSS). HRIS was measured by using the concept of behavior and found that independent variables significantly related to organizational performance. These results supported that the organizational learning capability as moderating variable influenced the relationship between HRIS and organizational performance. The model stresses the importance of HRIS which supports the organizational performance at public universities. The results of this study indicate that at public universities in West Sumatra, the improvement of HRIS will lead to higher levels of organizational performance. Results of this study are expected to provide benefits to all stakeholders who have an interest in higher education, especially in information technology and performance.
Early detection with renal Doppler resistive index measurements of hemorrhagic shock in polytrauma patients

Background: Poly trauma is a major cause of morbidity and mortality in both developed and developing countries. The aim was to investigate whether renal Doppler RI changes occur early with posttraumatic bleeding and whether the renal Doppler RI may enable accurate prediction of occult hypoperfusion and thus be predictive of the development of hemorrhagic shock in polytrauma patients. Methods: It was a prospective study involving patients admitted in the causality and evaluated by radiology department. Study was done in a period of 6 months from June 2016-December 2016. Renal Doppler RI was measured in 48 hemodynamically stable adult patients admitted in emergency because of polytrauma. Results: 26 patients developed hemorrhagic shock, and 22 did not. Hemorrhagic shock group, as compared with the nonhemorrhagic shock group, had higher renal Doppler RI (mean, 0.79±0.11 [standard deviation] vs 0.61±0.2; P<0.01), injury severity score (mean, 33±12 vs 25±9; P<0.01), and standard base excess (mean, -4.0mEq/L±4 vs 1mEq/L±3; P≤0.05) values. At logistic regression analysis, a renal Doppler RI greater than 0.9 was the only independent risk factor for progression to hemorrhagic shock (P<0.001). Conclusions: Renal Doppler RI measurement may represent a clinically useful non-invasive method for the early detection of occult hemorrhagic shock.