Conditional entropy of ordinal patterns

In this paper we investigate a quantity called conditional entropy of ordinal patterns, akin to the permutation entropy. The conditional entropy of ordinal patterns describes the average diversity of the ordinal patterns succeeding a given ordinal pattern. We observe that this quantity provides a good estimation of the Kolmogorov-Sinai entropy in many cases. In particular, the conditional entropy of ordinal patterns of a finite order coincides with the Kolmogorov-Sinai entropy for periodic dynamics and for Markov shifts over a binary alphabet. Finally, the conditional entropy of ordinal patterns is computationally simple and thus can be well applied to real-world data

Capital leaving no one behind? : an empirical study of impact venture capital investments into the sustainable development goals

Purpose: Achieving the Sustainable Development Goals (SDGs) requires substantial resource mobilization from the private sector to bridge the estimated annual funding gap of $2.5 trillion. Scholars recognize impact investing as part of that solution, but empirical studies in the nascent field are scarce. This study analyses funding patterns of impact venture capital towards the SDGs addressed by social ventures and contextualizes them geographically. Design/methodology/approach: To understand which of the SDGs receive the highest/lowest funding amounts from investors, a sample of 695 impact investment deals between 2017-2021 is collected from a leading financial database. Subsequently, the ventures are manually matched with their corresponding SDGs, and multiple regression models analyse the effect of those SDGs on the deal size while controlling for external factors. Findings: It becomes evident that neither the hypothesized SDGs nor their overarching pillars (planet, people, prosperity, and partnerships) positively influence the funding amount on a global scale. Nevertheless, some of the goals do receive significantly more/less financial attention from impact investors in particular geographies. Implications: On the one hand, the results outline opportunities for impact investors to tackle underfunded SDG segments across several geographies and understand how past capital was allocated to shape future decision-making. On the other hand, policymakers can utilize the insights to identify which goals receive lower funding and supplement the lack of private capital through blended finance initiatives. This dissertation calls for further empirical research in the integrated field of impact investing and the SDGs.Objetivo: Atingir os Objetivos de Desenvolvimento Sustentável (ODS) requer uma mobilização substancial de recursos do setor privado para superar a lacuna de financiamento anual estimada em$2,5 trilhões. Os estudiosos reconhecem o impacto do investimento como parte dessa solução, mas os estudos empíricos no campo nascente são escassos. Este estudo analisa os padrões de financiamento do capital de risco de impacto em direção aos ODS abordados pelos empreendimentos sociais e os contextualiza geograficamente. Metodologia: Para entender qual dos ODS recebe o maior/menor financiamento dos investidores, uma amostra de 695 negócios de investimento de impacto entre 2017-2021 é coletada de um banco de dados financeiro. Posteriormente, os empreendimentos são combinados manualmente com seus ODS correspondentes, e modelos de regressão analisam o efeito desses ODS sobre o tamanho do negócio enquanto controlam fatores externos. Resultados: Torna-se evidente que nem as hipóteses dos ODS nem seus pilares (planeta, pessoas, prosperidade e parcerias) influenciam positivamente o valor do financiamento em escala global. No entanto, alguns dos objetivos recebem significativamente mais/menos atenção financeira dos investidores de impacto em determinadas geografias. Implicações: Por um lado, os resultados esboçam oportunidades para os investidores de impacto enfrentarem segmentos sub-financiados dos ODS em várias geografias e entenderem como o capital passado foi alocado para moldar a tomada de decisões futuras. Por outro lado, os formuladores de políticas podem utilizar as idéias para identificar quais objetivos recebem menos financiamento e complementar com fundos públicos. Esta dissertação exige mais pesquisas empíricas no campo integrado do investimento de impacto e dos ODS

Einstein-Podolsky-Rosen correlations from colliding Bose-Einstein condensates

We propose an experiment which can demonstrate quantum correlations in a physical scenario as discussed in the seminal work of Einstein, Podolsky and Rosen. Momentum-entangled massive particles are produced via the four-wave mixing process of two colliding Bose-Einstein condensates. The particles' quantum correlations can be shown in a double double-slit experiment or via ghost interference.Comment: 5 pages, 5 figures, published versio

Disruption of the blood-brain barrier by intra-arterial administration of papaverine: a technical note

Introduction: Various endovascular techniques can be used to treat cerebral vasospasm after aneurysmal subarachnoid haemorrhage (SAH) including intra-arterial administration of vasodilator drugs such as papaverine or nicardipine and balloon dilatation of the affected vessel segment. Papaverine is known to have side effects, and we report a possible new one. Materials and methods: After the treatment of cerebral vasospasm in a SAH patient by intra-arterial administration of papaverine into the left posterior cerebral artery, severe mesencephalic extravasation of blood and contrast media was detected. Results: After reviewing the literature, the authors conclude that interruption of the blood-brain barrier by papaverine most likely combined with a secondary hyperperfusion phenomena, and perhaps a direct toxic effect on brain tissue was the mechanism of this major complication. Conclusion: In treating vasospasm in areas with a high density of perforating arteries, especially in the posterior circulation, papaverine should be used cautiously because a safe regimen has yet to be established. In this situation, alternative agents such as calcium channel blockers could be considered, but evidence-based data are still missin

The mental health impact of the ongoing Russian-Ukrainian war six months after the Russian Invasion of Ukraine

Objective: This study aimed to investigate the impact of the ongoing war in Ukraine on the mental health of Ukrainians, focusing on war-induced trauma, disturbances in self-organization, post-traumatic stress disorder, complex post-traumatic stress disorder, anxiety, stress, and depression. Method: Data was collected from 703 participants six months after the full-scale invasion using a structured questionnaire that included sections on socio-demographic information, trauma-related issues, and mental health. Results: The study found that levels of depression and anxiety were relatively low, while stress and resilience were relatively high among Ukrainians affected by the war. However, those who were directly exposed to military actions, physical violence, or severe human suffering had higher levels of anxiety, depression, stress, and trauma-related symptoms. The war experience varied by gender, age, and living conditions. Participants who stayed in Ukraine had significantly lower anxiety, depression, stress, and trauma-related symptoms compared to those who moved abroad. Anxiety, depression, stress, low resilience, and subjective satisfaction with living conditions were predictors of trauma-related symptoms, including PTSD and CPTSD. Conclusions: These findings suggest that the mental health of Ukrainians affected by the war was impacted differently depending on their level of exposure to violence and their living conditions. Additionally, the study identified several predictors of trauma-related symptoms, including PTSD and CPTSD, such as anxiety, depression, stress, low resilience, and subjective satisfaction with living conditions. Future research should further explore the relationships between trauma type, sociodemographic factors, resilience, stress, anxiety, depression, and PTSD and CPTSD to better understand the mediation mechanisms underlying these relationships and to develop effective interventions to support the well-being of Ukrainians during this difficult time

No More Missing Inventory: Blockchain and RFID Technology Applications within the Retail Inventory Management System

Over the last two years blockchain technology has presented itself as a potential digital transformation that could disrupt and revitalize many business models. However, this digital transformation is still new and many companies grapple with possible applications of its theoretically sound benefits. Academic research is scarce and often limited to high level perspectives on how blockchain can benefit businesses in general. The time is right for exploring specific applications of the technology. This research considers how the digital transformation to blockchain could impact inventory management practices within the retail industry. The research relies on data collected through phenomenological interviews with management personnel of three clothing retail store franchisees