scholarly journals Quantitative Assessment of the Impact of Geometric Distortions and Their Correction on fMRI Data Analyses

2021 ◽  
Vol 15 ◽  
Author(s):  
Rodolfo Abreu ◽  
João Valente Duarte
Keyword(s):  
Positive Impact ◽  
Reversed Phase ◽  
Distortion Correction ◽  
Fmri Data ◽  
Planar Imaging ◽  
Pixel Intensity ◽  
Susceptibility Artifact ◽  
Geometric Distortions ◽  
Data Analyses ◽  
The Impact

Functional magnetic resonance imaging (fMRI) data is typically collected with gradient-echo echo-planar imaging (GE-EPI) sequences, which are particularly prone to the susceptibility artifact as a result of B0 field inhomogeneity. The component derived from in-plane spin dephasing induces pixel intensity variations and, more critically, geometric distortions. Despite the physical mechanisms underlying the susceptibility artifact being well established, a systematic investigation on the impact of the associated geometric distortions, and the direct comparison of different approaches to tackle them, on fMRI data analyses is missing. Here, we compared two different distortion correction approaches, by acquiring additional: (1) EPI data with reversed phase encoding direction (TOPUP), and (2) standard (and undistorted) GE data at two different echo times (GRE). We first characterized the geometric distortions and the correction approaches based on the estimated ΔB0 field offset and voxel shift maps, and then conducted three types of analyses on the distorted and corrected fMRI data: (1) registration into structural data, (2) identification of resting-state networks (RSNs), and (3) mapping of task-related brain regions of interest. GRE estimated the largest voxel shifts and more positively impacted the quality of the analyses, in terms of the (significantly lower) cost function of the registration, the (higher) spatial overlap between the RSNs and appropriate templates, and the (significantly higher) sensitivity of the task-related mapping based on the Z-score values of the associated activation maps, although also evident when considering TOPUP. fMRI data should thus be corrected for geometric distortions, with the choice of the approach having a modest, albeit positive, impact on the fMRI analyses.

scholarly journals The impact of T1 versus EPI spatial normalization templates for fMRI data analyses

2017 ◽  
Vol 38 (11) ◽  
pp. 5331-5342 ◽  
Author(s):  
Vince D. Calhoun ◽  
Tor D. Wager ◽  
Anjali Krishnan ◽  
Keri S. Rosch ◽  
Karen E. Seymour ◽  
...  
Keyword(s):  
Fmri Data ◽  
Spatial Normalization ◽  
Data Analyses ◽  
The Impact

scholarly journals Using synthetic MR images for field map-less distortion correction

2021 ◽  
Author(s):  
David Florentino Montez ◽  
Andrew N. Van ◽  
Ryland L. Miller ◽  
Nicole A. Seider ◽  
Scott Marek ◽  
...  
Keyword(s):  
Image Contrast ◽  
Distortion Correction ◽  
Fmri Data ◽  
Synthetic Image ◽  
Planar Imaging ◽  
Mr Images ◽  
Anatomical Images ◽  
Map Data ◽  
Echo Planar

Functional MRI (fMRI) data acquired using echo-planar imaging (EPI) is highly distorted by magnetic field inhomogeneity. Distortion combined with underlying differences in image contrast between EPI and T1-weighted and T2-weighted (T1w/T2w) structural images makes the alignment of functional and anatomical images a challenge. Typically, separately acquired field map data are used to correct fMRI distortions and a flexible cost function insensitive to cross-modal differences in image contrast and intensity is used for aligning fMRI and anatomical images. The quality of alignment achieved with this approach can vary greatly and depends on the availability and quality of field map data. To address this issue, we developed Synth, a software package for distortion correction and cross-modal image registration that does not require separately acquired field map data. Synth combines information from T1w/T2w anatomical images to construct an idealized undistorted synthetic image that has similar contrast and intensity properties to fMRI data. The undistorted synthetic image then serves as an effective reference for individual-specific nonlinear unwarping to correct fMRI distortions. We demonstrate that Synth reliably outperforms other standard registration and distortion correction approaches that utilize field maps in both pediatric (ABCD: Adolescent Brain Cognitive Development) and adult (MSC: Midnight Scan Club) data. Field map-less distortion correction with Synth allows accurate and precise registration of fMRI data with missing or corrupted field map information.

Multidisciplinary team decision is rare and decreasing in percutaneous vascular interventions despite positive impact on in-hospital outcomes

VASA ◽  
2019 ◽  
Vol 48 (3) ◽  
pp. 262-269 ◽  
Author(s):  
Christian-Alexander Behrendt ◽  
Tilo Kölbel ◽  
Thea Schwaneberg ◽  
Holger Diener ◽  
Ralf Hohnhold ◽  
...  
Keyword(s):  
Multidisciplinary Team ◽  
Positive Impact ◽  
Cross Sectional Study ◽  
Invasive Treatment ◽  
Cross Sectional ◽  
Hospital Outcomes ◽  
Vascular Intervention ◽  
Medical Specialties ◽  
Team Decision ◽  
The Impact

Abstract. Background: Worldwide prevalence of peripheral artery disease (PAD) is increasing and peripheral vascular intervention (PVI) has become the primary invasive treatment. There is evidence that multidisciplinary team decision-making (MTD) has an impact on in-hospital outcomes. This study aims to depict practice patterns and time changes regarding MTD of different medical specialties. Methods: This is a retrospective cross-sectional study design. 20,748 invasive, percutaneous PVI of PAD conducted in the metropolitan area of Hamburg (Germany) were consecutively collected between January 2004 and December 2014. Results: MTD prior to PVI was associated with lower odds of early unsuccessful termination of the procedures (Odds Ratio 0.662, p < 0.001). The proportion of MTD decreased over the study period (30.9 % until 2009 vs. 16.6 % from 2010, p < 0.001) while rates of critical limb-threatening ischemia (34.5 % vs. 42.1 %), patients´ age (70 vs. 72 years), PVI below-the-knee (BTK) (13.2 % vs. 22.4 %), and rates of severe TASC C/D lesions BTK (43.2 % vs. 54.2 %) increased (all p < 0.001). Utilization of MTD was different between medical specialties with lowest frequency in procedures performed by internists when compared to other medical specialties (7.1 % vs. 25.7 %, p < 0.001). Conclusions: MTD prior to PVI is associated with technical success of the procedure. Nonetheless, rates of MTD prior to PVI are decreasing during the study period. Future studies should address the impact of multidisciplinary vascular teams on long-term outcomes.

Impact of external currency exposures on macroeconomic policies

2020 ◽  
pp. 23-40
Author(s):  
I. V. Prilepskiy
Keyword(s):  
Monetary Policy ◽  
Exchange Rate ◽  
Positive Impact ◽  
Exchange Rate Regime ◽  
Macroeconomic Policies ◽  
Panel Regressions ◽  
Financial Account ◽  
Currency Exposure ◽  
Cross Country ◽  
The Impact

Based on cross-country panel regressions, the paper analyzes the impact of external currency exposures on monetary policy, exchange rate regime and capital controls. It is determined that positive net external position (which, e.g., is the case for Russia) is associated with a higher degree of monetary policy autonomy, i.e. the national key interest rate is less responsive to Fed/ECB policy and exchange rate fluctuations. Therefore, the risks of cross-country synchronization of financial cycles are reduced, while central banks are able to place a larger emphasis on their price stability mandates. Significant positive impact of net external currency exposure on exchange rate flexibility and financial account liberalization is only found in the context of static models. This is probably due to the two-way links between incentives for external assets/liabilities accumulation and these macroeconomic policy tools.

Evaluation of the impact of public investment programs on social and economic performance of territories

2019 ◽  
pp. 109-123
Author(s):  
I. E. Limonov ◽  
M. V. Nesena
Keyword(s):  
Bayesian Modeling ◽  
Positive Impact ◽  
Public Investment ◽  
Difference In Differences ◽  
The Public ◽  
Export Activity ◽  
Regional Investment ◽  
The Difference ◽  
The Impact ◽  
Development Institution

The purpose of this study is to evaluate the impact of public investment programs on the socio-economic development of territories. As a case, the federal target programs for the development of regions and investment programs of the financial development institution — Vnesheconombank, designed to solve the problems of regional development are considered. The impact of the public interventions were evaluated by the “difference in differences” method using Bayesian modeling. The results of the evaluation suggest the positive impact of federal target programs on the total factor productivity of regions and on innovation; and that regional investment programs of Vnesheconombank are improving the export activity. All of the investments considered are likely to have contributed to the reduction of unemployment, but their implementation has been accompanied by an increase in social inequality.

Strategic Role of Zakat in Multidimensional Quality of Life in Sijunjung, Indonesia

2018 ◽  
Vol 15 (1) ◽  
pp. 55-72
Author(s):  
Herlin Hamimi ◽  
Abdul Ghafar Ismail ◽  
Muhammad Hasbi Zaenal
Keyword(s):  
Quality Of Life ◽  
Positive Impact ◽  
Wealth Distribution ◽  
Absolute Poverty ◽  
Before And After ◽  
The Status ◽  
Being There ◽  
The Impact

Zakat is one of the five pillars of Islam which has a function of faith, social and economic functions. Muslims who can pay zakat are required to give at least 2.5 per cent of their wealth. The problem of poverty prevalent in disadvantaged regions because of the difficulty of access to information and communication led to a gap that is so high in wealth and resources. The instrument of zakat provides a paradigm in the achievement of equitable wealth distribution and healthy circulation. Zakat potentially offers a better life and improves the quality of human being. There is a human quality improvement not only in economic terms but also in spiritual terms such as improving religiousity. This study aims to examine the role of zakat to alleviate humanitarian issues in disadvantaged regions such as Sijunjung, one of zakat beneficiaries and impoverished areas in Indonesia. The researcher attempted a Cibest method to capture the impact of zakat beneficiaries before and after becoming a member of Zakat Community Development (ZCD) Program in material and spiritual value. The overall analysis shows that zakat has a positive impact on disadvantaged regions development and enhance the quality of life of the community. There is an improvement in the average of mustahik household incomes after becoming a member of ZCD Program. Cibest model demonstrates that material, spiritual, and absolute poverty index decreased by 10, 5, and 6 per cent. Meanwhile, the welfare index is increased by 21 per cent. These findings have significant implications for developing the quality of life in disadvantaged regions in Sijunjung. Therefore, zakat is one of the instruments to change the status of disadvantaged areas to be equivalent to other areas.

Static and Dynamic Studies of Gasoline in View of its Octane Number and its Toxic Effect

2013 ◽  
Vol 12 (7) ◽  
pp. 451-459
Author(s):  
Ashraf Yehia El-Naggar ◽  
Mohamed A. Ebiad
Keyword(s):  
Toxic Effect ◽  
Aromatic Hydrocarbons ◽  
Octane Number ◽  
Liquid Fuel ◽  
Positive Impact ◽  
Hydrocarbon Composition ◽  
Different Temperatures ◽  
Different Seasons ◽  
The One ◽  
The Impact

Gasoline come primarily from petroleum cuts, it is the preferred liquid fuel in our lives. Two gasoline samples of octane numbers 91 and 95 from Saudi Arabia petrol stations were studied. This study was achieved at three different temperatures 20oC, 30oC and 50oC representing the change in temperatures of the different seasons of the year. Both the evaporated gases of light aromatic hydrocarbons (BTEX) of gasoline samples inside the tank were subjected to analyze qualitatively and quantitatively via capillary gas chromatography. The detailed hydrocarbon composition and the octane number of the studied gasoline samples were determined using detailed hydrocarbon analyzer. The idea of research is indicating the impact of light aromatic compounds in gasoline on the toxic effect of human and environment on the one hand, and on octane number of gasoline on the other hand. Although the value of octane number will be reduced but this will have a positive impact on the environment as a way to produce clean fuel.

Evaluating the return on religious capital in the Russian labor market

2020 ◽  
Vol 19 (9) ◽  
pp. 1671-1694
Author(s):  
R.M. Mel'nikov
Keyword(s):  
Labor Market ◽  
Religious Identity ◽  
Work Experience ◽  
Church Attendance ◽  
Satisfaction With Life ◽  
Positive Impact ◽  
Religious Commitment ◽  
Religious Faith ◽  
Religious Capital ◽  
The Impact

Subject. The article addresses the impact of religious confession on wages and the likelihood of unemployment in Russia. Objectives. The aim is to test the hypothesis that religious faith and high church attendance are accompanied by an increase in employment earnings. Methods. Using the Russian Longitudinal Monitoring Survey data, I estimate the Mincer's extended equation with variables that characterize the respondent’s religious commitment. To assess the impact of religious identity and the activity rate of attendance at religious services on the likelihood of unemployment and life satisfaction, I use probit models. Results. The estimates demonstrate that the Russian labor market rewards men with moderate and high degree of religious commitment; their wage growth reaches seventeen percent of the level of non-believers with comparable education and work experience. However, faithful Muslim women are employed in the lowest paid areas. Religious faith and regular church attendance have a positive effect on satisfaction with life (significant for Orthodox Christian women). Conclusions. Positive impact of religious capital on income and employment can be attributed to the development of business qualities that are rewarded in the labor market, the mutual support of religious network participants. Therefore, it possible to consider religious capital, along with educational capital and health capital, as a component of human capital and a factor of socio-economic development.

IMPACT OF GOVERNMENT DEBT ON FINANCIAL SECURITY OF UKRAINE

2017 ◽  
Author(s):  
Olena Pikaliuk ◽  
◽  
Dmitry Kovalenko ◽  
Keyword(s):  
Economic Development ◽  
Public Debt ◽  
Positive Impact ◽  
The State ◽  
Financial Security ◽  
State Budget ◽  
The Public ◽  
Debt Security ◽  
The Stability ◽  
The Impact

One of the main criteria for economic development is the size of the public debt and its dynamics. The article considers the impact of public debt on the financial security of Ukraine. The views of scientists on the essence of public debt and financial security of the state are substantiated. An analysis of the dynamics and structure of public debt of Ukraine for 2014-2019. It is proved that one of the main criteria for economic development is the size of public debt and its dynamics. State budget deficit, attracting and using loans to cover it have led to the formation and significant growth of public debt in Ukraine. The volume of public debt indicates an increase in the debt security of the state, which is a component of financial security. Therefore, the issue of the impact of public debt on the financial security of Ukraine is becoming increasingly relevant. The constant growth and large amounts of debt make it necessary to study it, which will have a positive impact on economic processes that will ensure the stability of the financial system and enhance its security.

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