Stock Selection Strategies in Emerging Markets

Recent empirical evidence suggests that value and momentum strategies generate significant excess returns in emerging markets. We confirm these results and extend them in several directions. First, we examine a broader range of stock selection strategies, including strategies based on analysts' earnings revisions. We also consider multivariate strategies, whereby stocks are selected on multiple characteristics, and find that this enhances the overall performance. Excess returns also increase if country selection is incorporated into the strategies, but the risk of the strategies increases proportionally. Second, we test whether the strategies can be implemented successfully in practice by a large institutional investor, facing a lack of liquidity, restrictions on foreign ownership and substantial transaction costs. We find that even under such more realistic circumstances the strategies earn significant excess returns. Third, we examine several popular explanations for the excess returns. We find no evidence of higher market risk or lower liquidity of the strategies. Instead, based on the developments of earnings and earnings revisions after portfolio formation, we find that the results are consistent with behavioral explanations

Oscillatory Control over Representational States in Working Memory

In the visual world, attention is guided by perceptual goals activated in visual working memory (VWM). However, planning multiple-task sequences also requires VWM to store representations for future goals. These future goals need to be prevented from interfering with the current perceptual task. Recent findings have implicated neural oscillations as a control mechanism serving the implementation and switching of different states of prioritization of VWM representations. We review recent evidence that posterior alpha-band oscillations underlie the flexible activation and deactivation of VWM representations and that frontal delta-to-theta-band oscillations play a role in the executive control of this process. That is, frontal delta-to-theta appears to orchestrate posterior alpha through long-range oscillatory networks to flexibly set up and change VWM states during multitask sequences

RAB25 expression is epigenetically downregulated in oral and oropharyngeal squamous cell carcinoma with lymph node metastasis

Oral and oropharyngeal squamous cell carcinoma (OOSCC) have a low survival rate, mainly due to metastasis to the regional lymph nodes. For optimal treatment of these metastases, a neck dissection is required; however, inaccurate detection methods results in under- and over-treatment. New DNA prognostic methylation biomarkers might improve lymph node metastases detection. To identify epigenetically regulated genes associated with lymph node metastases, genome-wide methylation analysis was performed on 6 OOSCC with (pN+) and 6 OOSCC without (pN0) lymph node metastases and combined with a gene expression signature predictive for pN+ status in OOSCC. Selected genes were validated using an independent OOSCC cohort by immunohistochemistry and pyrosequencing, and on data retrieved from The Cancer Genome Atlas. A two-step statistical selection of differentially methylated sequences revealed 14 genes with increased methylation status and mRNA downregulation in pN+ OOSCC. RAB25, a known tumor suppressor gene, was the highest-ranking gene in the discovery set. In the validation sets, both RAB25 mRNA (P = 0.015) and protein levels (P = 0.012) were lower in pN+ OOSCC. RAB25 mRNA levels were negatively correlated with RAB25 methylation levels (P < 0.001) but RAB25 protein expression was not. Our data revealed that promoter methylation is a mechanism resulting in downregulation of RAB25 expression in pN+ OOSCC and decreased expression is associated with lymph node metastasis. Detection of RAB25 methylation might contribute to lymph node metastasis diagnosis and serve as a potential new therapeutic target in OOSCC

Cessations of consciousness in meditation: Advancing a scientific understanding of nirodha samāpatti

Absence of consciousness can occur due to a concussion, anesthetization, intoxication, epileptic seizure, or other fainting/syncope episode caused by lack of blood flow to the brain. However, some meditation practitioners also report that it is possible to undergo a total absence of consciousness during meditation, lasting up to 7 days, and that these “cessations” can be consistently induced. One form of extended cessation (i.e., nirodha samāpatti) is thought to be different from sleep because practitioners are said to be completely impervious to external stimulation. That is, they cannot be 'woken up' from the cessation state as one might be from a dream. Cessations are also associated with the absence of any time experience or tiredness, and are said to involve a stiff rather than a relaxed body. Emergence from meditation-induced cessations is said to have profound effects on subsequent cognition and experience (e.g., resulting in a sudden sense of clarity, openness, and possibly insights). In this paper, we briefly outline the historical context for cessation events, present preliminary data from two labs, set a research agenda for their study, and provide an initial framework for understanding what meditation induced cessation may reveal about the mind and brain. We conclude by integrating these so-called nirodha and nirodha samāpatti experiences—as they are known in classical Buddhism—into current cognitive-neurocomputational and active inference frameworks of meditation

Distinct Biomarker Profiles and Clinical Characteristics in T1-T2 Glottic and Supraglottic Carcinomas

Background: In early stage laryngeal squamous cell carcinoma (LSCC) radiotherapy with curative intent is a major treatment modality. TNM classification is used to define patients eligible for radiotherapy. Studies in early stage glottic LSCC identified several predictive biomarkers associated with local control. However, we recently reported that this predictive value could not be confirmed in supraglottic LSCC. Objective: To examine whether clinical behavior and protein expression patterns of these biomarkers differ between glottic and supraglottic LSCC. Study Design: Retrospective cohort study. Methods: Tumor tissue sections of 196 glottic and 80 supraglottic T1-T2 LSCC treated primarily with RT were assessed immunohistochemically for expression of pAKT, Ki-67 and β-Catenin. Expression data of HIF-1α, CA-IX, OPN, FADD, pFADD, Cyclin D1, Cortactin and EGFR in the same cohort of glottic and supraglottic LSCC, were retrieved from previously reported data. The relationship between glottic and supraglottic sublocalization and clinicopathological, follow-up, and immunohistochemical staining characteristics were evaluated using logistic regression and Cox regression analyses. Results: Glottic LSCC were correlated with male gender (P =.001), hoarseness as a primary symptom (P <.001), T1 tumor stage (P <.001), negative lymph node status (P <.001), and an older age at presentation (P =.004). Supraglottic LSCC patients developed more post-treatment distant metastasis when adjusted for gender, age, and T-status. While supraglottic LSCC was associated with higher expression of HIF-1α (P =.001), Cortactin (P <.001), EGFR (P <.001), and Ki-67 (P =.027), glottic LSCC demonstrated higher expression of CA-IX (P =.005) and Cyclin D1 (P =.001). Conclusion: Differences in clinicopathological and immunohistochemical staining characteristics suggest that T1-T2 glottic and supraglottic LSCC should be considered as different entities. Level of Evidence: N/A. Laryngoscope, 2020

PTEN Is Associated With Worse Local Control in Early Stage Supraglottic Laryngeal Cancer Treated With Radiotherapy

Objectives: The aim of this study was to establish the prognostic value of the epidermal growth factor receptor (EGFR) and phosphatase and tensin homolog deleted on chromosome 10 (PTEN) expression on local control in patients with early stage supraglottic laryngeal squamous cell carcinoma (LSCC) treated with radiotherapy only. Study design: Retrospective cohort study. Methods: Immunohistochemical staining for EGFR and PTEN was performed on pretreatment biopsies of a selected well-defined homogeneous group of 52 patients with T1-T2 supraglottic LSCC treated with radiotherapy between 1990 and 2008. Kaplan-Meier analysis and univariate and multivariate Cox Regression analyses were performed to correlate clinical data and expression levels of EGFR and PTEN with local control. Results: Kaplan-Meier survival analysis and Cox Regression analysis showed a significant association between PTEN expression and local control (hazard ratio [HR] = 3.26, 95% confidence interval [CI] = 1.14-9.33, P = .027) and between lymph node status and local control (HR = 3.60, 95% CI = 1.26-10.31, P = .017). Both were independent prognostic factors in a multivariate analysis (HR = 3.28, 95% CI = 1.14-9.39, P = .027 and HR = 3.62, 95% CI = 1.26-10.37, P = .017, respectively). There was no significant association between EGFR expression and local control (HR = 1.32, 95% CI = 1.17-10.14, P = .79). Conclusion: This study showed an association between both high PTEN expression and the presence of lymph node metastasis and deteriorated local control in early stage supraglottic LSCC treated with radiotherapy. Level of Evidence: NA

Transrectus sheath pre-peritoneal (TREPP) procedure versus totally extraperitoneal (TEP) procedure and Lichtenstein technique:a propensity-score-matched analysis in Dutch high-volume regional hospitals

PURPOSE: Results of the most commonly used inguinal hernia repair techniques often originate from expert centers or from randomized controlled studies. In this study, we portray daily-practice results of a high-volume, regional surgical group in the Netherlands, comparing TREPP (open (posterior) transrectus sheath pre-peritoneal) with Lichtenstein (open anterior) and TEP (endoscopic (posterior) totally extraperitoneal). We hypothesize that the TREPP shows more favorable outcome compared to the current gold standard procedures: TEP and Lichtenstein. METHODS: Between January 2016 and December 2018, 3285 consecutive patients underwent surgical treatment and were included for analysis. The outcome measures were postoperative pain, recurrence rate and other surgical complications. Propensity-score matching was used to address potential selection bias. RESULTS: After propensity-score matching, there was no statistically significant difference in postoperative pain in the TREPP group compared to the Lichtenstein group (TREPP 7.3% versus Lichtenstein 6.3%; p = 0.67) nor in TREPP compared to TEP (TREPP 7.4% versus TEP 4.1%; p = 0.064). There was no statistically significant difference in recurrences in the TREPP group compared to Lichtenstein (3.8% vs 2.5%; p = 0.42), nor in the TREPP versus TEP comparison (3.9% vs 2.8%; p = 0.55) CONCLUSION: This study compares TREPP with Lichtenstein and TEP in the presence of postoperative pain, recurrences and other adverse outcomes. After propensity-score matching, no statistically significant difference in postoperative pain or recurrences remained between either TREPP compared to Lichtenstein, or TREPP compared to TEP. Based on these results, TREPP, Lichtenstein and TEP showed comparable results in postoperative pain, recurrences and other surgical site complications

Loss of p53 triggers Wnt-dependent systemic inflammation to drive breast cancer metastasis

Cancer-associated systemic inflammation is strongly linked to poor disease outcome in patients with cancer1,2. For most human epithelial tumour types, high systemic neutrophil-to-lymphocyte ratios are associated with poor overall survival3, and experimental studies have demonstrated a causal relationship between neutrophils and metastasis4,5. However, the cancer-cell-intrinsic mechanisms that dictate the substantial heterogeneity in systemic neutrophilic inflammation between tumour-bearing hosts are largely unresolved. Here, using a panel of 16 distinct genetically engineered mouse models for breast cancer, we uncover a role for cancer-cell-intrinsic p53 as a key regulator of pro-metastatic neutrophils. Mechanistically, loss of p53 in cancer cells induced the secretion of WNT ligands that stimulate tumour-associated macrophages to produce IL-1β, thus driving systemic inflammation. Pharmacological and genetic blockade of WNT secretion in p53-null cancer cells reverses macrophage production of IL-1β and subsequent neutrophilic inflammation, resulting in reduced metastasis formation. Collectively, we demonstrate a mechanistic link between the loss of p53 in cancer cells, secretion of WNT ligands and systemic neutrophilia that potentiates metastatic progression. These insights illustrate the importance of the genetic makeup of breast tumours in dictating pro-metastatic systemic inflammation, and set the stage for personalized immune intervention strategies for patients with cancer

Cochlear-optimized treatment planning in photon and proton radiosurgery for vestibular schwannoma patients

ObjectiveTo investigate the potential to reduce the cochlear dose with robotic photon radiosurgery or intensity-modulated proton therapy planning for vestibular schwannomas.Materials and MethodsClinically delivered photon radiosurgery treatment plans were compared to five cochlear-optimized plans: one photon and four proton plans (total of 120). A 1x12 Gy dose was prescribed. Photon plans were generated with Precision (Cyberknife, Accuray) with no PTV margin for set-up errors. Proton plans were generated using an in-house automated multi-criterial planning system with three or nine-beam arrangements, and applying 0 or 3 mm robustness for set-up errors during plan optimization and evaluation (and 3 % range robustness). The sample size was calculated based on a reduction of cochlear Dmean > 1.5 Gy(RBE) from the clinical plans, and resulted in 24 patients.ResultsCompared to the clinical photon plans, a reduction of cochlear Dmean > 1.5 Gy(RBE) could be achieved in 11/24 cochlear-optimized photon plans, 4/24 and 6/24 cochlear-optimized proton plans without set-up robustness for three and nine-beam arrangement, respectively, and in 0/24 proton plans with set-up robustness. The cochlea could best be spared in cases with a distance between tumor and cochlea. Using nine proton beams resulted in a reduced dose to most organs at risk.ConclusionCochlear dose reduction is possible in vestibular schwannoma radiosurgery while maintaining tumor coverage, especially when the tumor is not adjacent to the cochlea. With current set-up robustness, proton therapy is capable of providing lower dose to organs at risk located distant to the tumor, but not for organs adjacent to it. Consequently, photon plans provided better cochlear sparing than proton plans.Otorhinolaryngolog