Relationships among repeated sprint tests and aerobic fitness in adolescent tennis players

The aim of this study was to determine the performance indices (ideal sprint time – IS, total sprint time – TS, and performance decrement – PD) of two repeated sprint test (RST) and to examine their relationships with the aerobic fitness of young tennis players. Fifteen young (age 14.7±1.0 yrs) tennis players performed three tests: an aerobic power test (20 m shuttle run), and two different RST protocols (12×20 m and 12×10 m runs). Peak heart rate was significantly higher in the 20 m protocol compared to the 10 m protocol while no significant difference was found in the PD of the two RST protocols. Significant positive correlations were found between the ISs and the TSs (r=0.946 and r=0.932, respectively), but not between the PDs of the two RST protocols. Significant negative correlations were found between TS and IS and aerobic fitness during the 10 m protocol (r=–0.594 and r=–0.595, respectively) and the 20 m protocol (r=–0.757 and r=–0.716, respectively), but not between PD and the aerobic fitness in both RST protocols. Both short and long RST protocols represent similar anaerobic capabilities. In addition, the aerobic energy system serves as a significant factor in both RST protocols. However, it seems that the involvement of the aerobic system is more significant in the long than in the short repetition RST protocol

Academic Scholarship in Light of the 2008 Financial Crisis: Textual Analysis of NBER Working Papers

Textual analysis of 14,270 NBER Working Papers published during 1999–2016 is done to assess the effects of the 2008 crisis on the economics literature. The volume of crisis-related WPs is counter-cyclical, lagging the financial-instability-index. WPs by the Monetary-Economics, Asset-Pricing, and Corporate-Finance program members, hardly refer to “crisis/crises” in the pre-crisis period. As the crisis develops, however, their study-efforts of crisis-related issues increase rapidly. In contrast, WPs in macroeconomics-related programs refer quite extensively in the pre-crisis period to “crisis/crises” and to crises-related topics. Overall, our findings are consistent with the claim that economists were not engaged sufficiently in crises studies before the 2008 crisis. However, counter to the popular image, as soon as the crisis began to unravel, the NBER affiliated economists responded dramatically by switching their focus and efforts to studying and understanding the crisis, its causes and its consequences

Academic Scholarship in Light of the 2008 Financial Crisis: Textual Analysis of NBER Working Papers

Textual analysis of the NBER Working Papers published during 1999–2016 is done to assess the effects of the 2007–2009 crisis on the academic literature. The volume of crisis-related WPs is counter-cyclical, lagging the financial-instability-index. WPs by the Monetary-Economics, Asset-Pricing, and Corporate-Finance program members, hardly refer to “crisis/crises” in the pre-crisis period. As the crisis develops, however, their study-efforts of crisis-related issues increase rapidly, focusing on the links between ‘Repo-and-Securitization’ and the crisis. In contrast, WPs in macroeconomics-related programs refer extensively to “crisis/crises” in the pre-crisis period. These WPs abandon topics of ‘Sudden-Stop’ and ‘Emerging-Markets’ as the crisis developed

Academic Scholarship in Light of the 2008 Financial Crisis: Textual Analysis of NBER Working Papers

Textual analysis of 14,270 NBER Working Papers published during 1999–2016 is done to assess the effects of the 2008 crisis on the economics literature. The volume of crisis-related WPs is counter-cyclical, lagging the financial-instability-index. WPs by the Monetary-Economics, Asset-Pricing, and Corporate-Finance program members, hardly refer to “crisis/crises” in the pre-crisis period. As the crisis develops, however, their study-efforts of crisis-related issues increase rapidly. In contrast, WPs in macroeconomics-related programs refer quite extensively in the pre-crisis period to “crisis/crises” and to crises-related topics. Overall, our findings are consistent with the claim that economists were not engaged sufficiently in crises studies before the 2008 crisis. However, counter to the popular image, as soon as the crisis began to unravel, the NBER affiliated economists responded dramatically by switching their focus and efforts to studying and understanding the crisis, its causes and its consequences

Economists in the 2008 Financial Crisis: Slow to See, Fast to Act

We study the economics and finance scholars’ reaction to the 2008 financial crisis using machine learning language analyses methods of Latent Dirichlet Allocation and dynamic topic modelling algorithms, to analyze the texts of 14,270 NBER working papers covering the 1999–2016 period. We find that academic scholars as a group were insufficiently engaged in crises’ studies before 2008. As the crisis unraveled, however, they switched their focus to studying the crisis, its causes, and consequences. Thus, the scholars were “slow-to-see,” but they were “fast-to-act.” Their initial response to the ongoing Covid-19 crisis is consistent with these conclusions

Predicting the risk of iliofemoral vascular complication in complex transfemoral-TAVR using new generation transcatheter devices.

OBJECTIVE: Design a predictive risk model for minimizing iliofemoral vascular complications (IVC) in a contemporary era of transfemoral-transcatheter aortic valve replacement (TF-TAVR). BACKGROUND: IVC remains a common complication of TF-TAVR despite the technological improvement in the new-generation transcatheter systems (NGTS) and enclosed poor outcomes and quality of life. Currently, there is no accepted tool to assess the IVC risk for calcified and tortuous vessels. METHODS: We reconstructed CT images of 516 propensity-matched TF-TAVR patients using the NGTS to design a predictive anatomical model for IVC and validated it on a new cohort of 609 patients. Age, sex, peripheral artery disease, valve size, and type were used to balance the matched cohort. RESULTS: IVC occurred in 214 (7.2%) patients. Sheath size (p = 0.02), the sum of angles (SOA) (p < .0001), number of curves (NOC) (p < .0001), minimal lumen diameter (MLD) (p < .001), and sheath-to-femoral artery diameter ratio (SFAR) (p = 0.012) were significant predictors for IVC. An indexed risk score (CSI) consisting of multiplying the SOA and NOC divided by the MLD showed 84.3% sensitivity and 96.8% specificity, when set to >100, in predicting IVC (C-stat 0.936, 95% CI 0.911-0.959, p < 0.001). Adding SFAR > 1.00 in a tree model increased the overall accuracy to 97.7%. In the validation cohort, the model predicted 89.5% of the IVC cases with an overall 89.5% sensitivity, 98.9% specificity, and 94.2% accuracy (C-stat 0.842, 95% CI 0.904-0.980, p < .0001). CONCLUSION: Our CT-based validated-model is the most accurate and easy-to-use tool assessing IVC risk and should be used for calcified and tortuous vessels in preprocedural planning

Mistakenly misinformed or intentionally deceived? Mis‐ and Disinformation perceptions on the Russian War in Ukraine among citizens in 19 countries

In information environments characterized by institutional distrust, fragmentation and the widespread dissemination of conspiracies and disinformation, citizens perceive misinformation as a salient and threatening issue. Especially amidst disruptive events and crises, news users are likely to believe that information is inaccurate or deceptive. Using an original 19‐country comparative survey study across diverse regions in the world (N = 19,037), we find that news users are likely to regard information on the Russian war in Ukraine as false. They are more likely to attribute false information to deliberative deception than to a lack of access to the war area or inaccurate expert knowledge. Russian sources are substantially more likely to be blamed for falsehoods than Ukrainian or Western sources – but these attribution biases depend on a country's position on the war. Our findings reveal that people mostly believe that falsehoods are intended to deceive them, and selectively associate misinformation with the opposed camp