An Entropy Approach to Measure the Dynamic Stock Market Efficiency

We measure stock market efficiency by drawing the comprehensive sample from Asia, Europe, Africa, North-South America, and Pacific Ocean regions and rank the cross-regional stock markets according to their level of informational efficiency. The study period spans from January 1, 1994, to August 3, 2017. We employ the approximate entropy approach and find that stock market efficiency evolves over the period. The degree and nature of evolution vary across regions and the development stage of the markets. The global, regional, domestic economic, and non-economic factors influence the adaptive nature of the stock markets. The emerging stock markets have improved efficiency by financial liberalization policy but are adversely affected by global shocks. The estimates validate the relevance of the adaptive market framework to describe the rejection of random walk without excess returns. The results suggest the growing presence of technical analysis and active portfolio managers. The emerging markets in Asia hold policy lessons for their peers. The findings suggest that global investors need to overcome the homogeneity bias as returns opportunities exist within the region and types of markets.

Egyptian Students Open to Digital Mental Health Care: Cross-Sectional Survey

Background

In Egypt, the shortage of mental health services, particularly for adolescents and young adults, is apparent. Electronic mental health (EMH) has been proposed as a solution to bridge the gap and better address the needs of young people. However, EMH is new to Egypt and its acceptability among target populations is crucial to its implementation and success.

Objective

The objective of this study is to explore the interest of Egyptian youth in EMH, identify perceived barriers to EMH, and inform the design of EMH tools to best address the needs of youth.

Methods

A web-based cross-sectional survey was distributed among medical students at Tanta University in Egypt. Chi-square and one-way analysis of variance tests were performed for inferential analyses using a significance level of .05.

Results

Of the 707 individuals who completed the survey (90.9% response rate), 60.5% (428) were female, 62% (438) lived in urban and suburban areas, and the mean age of the sample was 20.5 (SD 1.8) years. The vast majority of participants (522/707, 73.8%) had already used the internet to find information about mental health problems, but the information was unsatisfactory for about half of them (386/707, 54.6%). Almost all students reported that they would prefer web-based therapy if EMH were available through a trustworthy national web-based platform for youth mental health (601/707, 85%). Students believed that emotional difficulties, social support, and coping strategies were the main topics that EMH should help with. The most common perceived barriers for EMH use in Egypt were concerns about privacy (382/707, 54%) and a lack of technology literacy and unfamiliarity with EMH (352/707, 50%).

Conclusions

EMH is a promising strategy for addressing gaps in the mental health care for young people. To construct and implement a digital system of care that addresses the unique needs and preferences of youth, adolescents and young adults should be involved in the co-development and design.

Folic acid targets splenic extramedullary hemopoiesis to attenuate carbon black-induced coagulation-thrombosis potential

Due to its wide applications in tire and rubber products, carbon black (CB) implicates concerns on its safety during production, collection, and handling. Here we report that exposure CB, increases coagulation-thrombosis potential in a splenic extramedullary hemopoiesis (EMH)-dependent manner. Adult C57BL/6 mice are kept in whole-body inhalation chambers, and exposed to filtered room air (FRA) or CB for 28 consecutive days. CB exposure resulted in splenic EMH characterized with platelet precursor cells, megakaryocytes (MKs), hyperplasia and enhanced in vivo blood coagulation ability. Metabolomics analysis suggests significant enhance in PGE2 production but reduction in folic acid (FA) levels in murine serum following CB exposure. Mechanistically, activation of COX-dependent PGE2 production promotes IL-6 expression in splenic macrophages, which subsequently results in splenic EMH and increased platelet counts in circulation. Administration of FA protects the mice against CB-induced splenic EMH through inhibiting prostaglandin-endoperoxide synthase 2 (Ptgs2 or Cox2) and prostaglandin E synthase (Ptges) expression in splenic macrophages, eventually recover the coagulation capacity to normal level. The results strongly suggest the involvement of splenic EMH in response to CB exposure and subsequently increased coagulation-thrombosis potential. Supplementation with FA may be a candidate to prevent thrombosis potential attributable to CB exposure.

Entropy-Based Behavioural Efficiency of the Financial Market

The most known and used abstract model of the financial market is based on the concept of the informational efficiency (EMH) of that market. The paper proposes an alternative which could be named the behavioural efficiency of the financial market, which is based on the behavioural entropy instead of the informational entropy. More specifically, the paper supports the idea that, in the financial market, the only measure (if any) of the entropy is the available behaviours indicated by the implicit information. Therefore, the behavioural entropy is linked to the concept of behavioural efficiency. The paper argues that, in fact, in the financial markets, there is not a (real) informational efficiency, but there exists a behavioural efficiency instead. The proposal is based both on a new typology of information in the financial market (which provides the concept of implicit information—that is, that information ”translated” by the economic agents from observing the actual behaviours) and on a non-linear (more exactly, a logistic) curve linking the behavioural entropy to the behavioural efficiency of the financial markets. Finally, the paper proposes a synergic overcoming of both EMH and AMH based on the new concept of behavioural entropy in the financial market.

Complexity Changes in the US and China's Stock Markets: Differences, Causes, and Wider Social Implications

How different are the emerging and the well-developed stock markets in terms of efficiency? To gain insights into this question, we compared an important emerging market, the Chinese stock market, and the largest and the most developed market, the US stock market. Specifically, we computed the Lempel–Ziv complexity (LZ) and the permutation entropy (PE) from two composite stock indices, the Shanghai stock exchange composite index (SSE) and the Dow Jones industrial average (DJIA), for both low-frequency (daily) and high-frequency (minute-to-minute)stock index data. We found that the US market is basically fully random and consistent with efficient market hypothesis (EMH), irrespective of whether low- or high-frequency stock index data are used. The Chinese market is also largely consistent with the EMH when low-frequency data are used. However, a completely different picture emerges when the high-frequency stock index data are used, irrespective of whether the LZ or PE is computed. In particular, the PE decreases substantially in two significant time windows, each encompassing a rapid market rise and then a few gigantic stock crashes. To gain further insights into the causes of the difference in the complexity changes in the two markets, we computed the Hurst parameter H from the high-frequency stock index data of the two markets and examined their temporal variations. We found that in stark contrast with the US market, whose H is always close to 1/2, which indicates fully random behavior, for the Chinese market, H deviates from 1/2 significantly for time scales up to about 10 min within a day, and varies systemically similar to the PE for time scales from about 10 min to a day. This opens the door for large-scale collective behavior to occur in the Chinese market, including herding behavior and large-scale manipulation as a result of inside information.

Cytodiagnosis of extramedullary hematopoiesis in thyroid gland unravelling an asymptomatic hematological malignancy

Extramedullary hematopoeisis (EMH), also known as myeloid metaplasia can be seen in association with various hematological disorders. The common sites of EMH are liver, spleen and lymph nodes; but it can occur in almost any organ and in numerous locations. Involvement of the thyroid gland with EMH has rarely been reported. We present a case of EMH in the thyroid gland in an adult female diagnosed on fine-needle aspiration cytology (FNAC) which further helped in revealing an underlying myeloproliferative neoplasm; chronic myeloid leukemia (CML).

Extramedullary hematopoiesis involving the thyroid: Fine-needle aspiration features and literature review

INTRODUCTION

The thyroid has rarely been documented as a site of extramedullary hematopoiesis (EMH). We report the largest series to date, with nine cases of EMH, and compare our findings with previous reports of thyroid EMH.

MATERIALS AND METHODS

Thyroid nodule fine-needle aspirations (FNAs) were collected over a 4-year period. Thin layer preparations were examined and correlated with clinical features and ultrasound characteristics. A comprehensive review of the English literature was done, and the results were compared with the current series.

RESULTS

During the study period, 172,939 thyroid FNAs were examined. Nine samples (0.005%) contained trilineage bone marrow elements. Nodule calcifications were present in 7 patients. None of the patients had a history of a blood disorder, nor was there any evidence of a thyroid malignancy. Fifteen reports of 18 patients with thyroid EMH were identified in the English literature. Nodule calcifications were reported in 10 patients. Thyroid EMH was associated with primary myelofibrosis in 4 patients, and with chronic anemia in 1; calcifications were absent in 3 patients, and were not specified in the remaining 2. None had evidence of a thyroid malignancy.

CONCLUSIONS

Thyroidal EMH is an extremely uncommon finding. Clinical and sonographic features are nonspecific. Thyroid EMH is usually an incidental finding, most likely related to mature osseous metaplasia. An occasional association with hematologic disease has been reported, however. To date, there does not appear to be any association with thyroid malignancy and surgery is typically not indicated. Therefore, recognition at the time of FNA is essential.

Pleural fluid extramedullary hematopoiesis case report with review of the literature

Extramedullary hematopoiesis (EMH) is the trilineage formation of normal blood cells outside of the bone marrow. While predominantly seen in the spleen and liver, EMH rarely occurs in serous effusions. Accurate diagnosis requires recognition of megakaryocytes and other precursor hematopoietic elements. We present a case of pleural fluid EMH in a patient with primary myelofibrosis and developing leukemia, with a review of the literature, prognostic implications and diagnostic challenges.

Basophils and allergic inflammation

Basophils were discovered by Paul Ehrlich in 1879 and represent the least abundant granulocyte population in mammals. The relative rarity of basophils and their phenotypic similarities with mast cells resulted in this cell lineage being historically overlooked, both clinically and experimentally. However, recent studies in human subjects and murine systems have shown that basophils perform nonredundant effector functions and significantly contribute to the development and progression of TH2 cytokine-mediated inflammation. Although the potential functions of murine and human basophils have provoked some controversy, recent genetic approaches indicate that basophils can migrate into lymphoid tissues and, in some circumstances, cooperate with other immune cells to promote optimal TH2 cytokine responses in vivo. This article provides a brief historical perspective on basophil-related research and discusses recent studies that have identified previously unappreciated molecules and pathways that regulate basophil development, activation, and function in the context of allergic inflammation. Furthermore, we highlight the unique effector functions of basophils and discuss their contributions to the development and pathogenesis of allergic inflammation in human disease. Finally, we discuss the therapeutic potential of targeting basophils in preventing or alleviating the development and progression of allergic inflammation.

Ectopic bone formation in severely combat-injured orthopedic patients -- a hematopoietic niche

Combat-related heterotopic ossification (HO) has emerged as a common and problematic complication of modern wartime extremity injuries, contributing to substantial patient morbidity and loss of function. We have previously reported that HO-forming patients exhibit a more pronounced systemic and local inflammatory response very early in the wound healing process. Moreover, traumatized muscle-derived mesenchymal progenitor cells from these patients have a skewed differentiation potential toward bone. Here, we demonstrate that HO lesions excised from this patient population contain highly vascularized, mature, cancellous bone containing adipogenic marrow. Histologic analysis showed immature hematopoietic cells located within distinct foci in perivascular regions. The adipogenic marrow often contained low numbers of functional erythroid (BFU-E), myeloid (CFU-GM, CFU-M) and multilineage (CFU-GEMM) colony-forming hematopoietic progenitor cells (HPCs). Conversely, tissue from control muscle and non-HO traumatic wound granulation tissue showed no evidence of hematopoietic progenitor cell activity. In summary, our findings suggest that ectopic bone can provide an appropriate hematopoietic microenvironment for supporting the proliferation and differentiation of HPCs. This reactive and vibrant cell population may help maintain normal hematopoietic function, particularly in those with major extremity amputations who have sustained both massive blood loss, prompting systemic marrow stimulation, as well as loss of available native active marrow space. These findings begin to characterize the functional biology of ectopic bone and elucidate the interactions between HPC and non-hematopoietic cell types within the ectopic intramedullary hematopoietic microenvironmental niche identified.

Loss of PML cooperates with mutant p53 to drive more aggressive cancers in a gender-dependent manner

p53 mutations and downregulation of promyelocytic leukemia (PML) are common genetic alterations in human cancers. In healthy cells these two key tumor suppressors exist in a positive regulatory loop, promoting cell death and cellular senescence. However, the influence of their interplay on tumorigenesis has not been explored directly in vivo. The contribution of PML to mutant p53 driven cancer was evaluated in a mouse model harboring a p53 mutation (p53 (wild-type/R172H) ) that recapitulates a frequent p53 mutation (p53 (R175H) ) in human sporadic and Li-Fraumeni cancers. These mice with PML displayed perturbation of the hematopoietic compartment, manifested either as lymphoma or extramedullary hematopoiesis (EMH). EMH was associated with peripheral blood leucocytosis and macrocytic anemia, suggestive of myeloproliferative- myelodysplastic overlap. In contrast, a complete loss of PML from these mice resulted in a marked alteration in tumor profile. While the incidence of lymphomas was unaltered, EMH was not detected and the majority of mice succumbed to sarcomas. Further, males lacking PML exhibited a high incidence of soft tissue sarcomas and reduced survival, while females largely developed osteosarcomas, without impact on survival. Together, these findings demonstrate that PML is an important tumor suppressor dictating disease development in a pertinent mouse model of human cancer.  

KEY POINTS

(1) A mutant p53 allele disrupts hematopoiesis in mice, by promoting lymphomas and myeloproliferative / myelodysplastic overlap. (2) Coincidental p53 allele mutation and PML loss shifts the tumor profile toward sarcoma formation, which is paralleled in human leiomyosarcomas (indicated by immunohistochemistry; IHC).