Sparse Index Tracking: Simultaneous Asset Selection and Capital Allocation via ℓ0\ell_0-Constrained Portfolio

Sparse index tracking is one of the prominent passive portfolio management strategies that construct a sparse portfolio to track a financial index. A sparse portfolio is desirable over a full portfolio in terms of transaction cost reduction and avoiding illiquid assets. To enforce the sparsity of the portfolio, conventional studies have proposed formulations based on $\ell_p$-norm regularizations as a continuous surrogate of the $\ell_0$-norm regularization. Although such formulations can be used to construct sparse portfolios, they are not easy to use in actual investments because parameter tuning to specify the exact upper bound on the number of assets in the portfolio is delicate and time-consuming. In this paper, we propose a new problem formulation of sparse index tracking using an $\ell_0$-norm constraint that enables easy control of the upper bound on the number of assets in the portfolio. In addition, our formulation allows the choice between portfolio sparsity and turnover sparsity constraints, which also reduces transaction costs by limiting the number of assets that are updated at each rebalancing. Furthermore, we develop an efficient algorithm for solving this problem based on a primal-dual splitting method. Finally, we illustrate the effectiveness of the proposed method through experiments on the S\&P500 and NASDAQ100 index datasets.Comment: Submitted to IEEE Open Journal of Signal Processin

The Relationship Between Head Motion Synchronization and Empathy in Unidirectional Face-to-Face Communication

Embodied synchronization is widely observed in human communication, and is considered to be important in generating empathy during face-to-face communication. However, the quantitative relationship between body motion synchronization and degree of empathy is not fully understood. Therefore, we focused on head motion to investigate phase and frequency differences in head motion synchronization in relation to degree of empathy. We specifically conducted a lecture-based experiment using controlled spoken text divided into two parts: high empathy and low empathy. During the lecture, we measured the acceleration of speakers’ and listeners’ head motions using an accelerometer, and calculated the synchronization between the time-series data from their acceleration norms. The results showed greater head motion synchronization during high empathy. During high empathy, the speakers’ head motions began before those of listeners’ in the medium (2.5 to 3.5 Hz) and high (4.0 to 5.0 Hz) frequency ranges, whereas the speakers’ head motions tended to start later than those of the listeners’ in the low (1.0 to 2.0 Hz) and medium (2.5 to 3.5 Hz) frequency ranges. This suggests that the degree of empathy is reflected by a different relationship between the phase and frequency of head motion synchronization during face-to-face communication

High platelet reactivity is a predictor of left ventricular remodelling in patients with acute myocardial infarction

Aims Acute myocardial infarction (AMI) is associated with left ventricular remodelling (LVR), which leads to progressive heart failure. Platelets play a pivotal role in promoting systemic and cardiac inflammatory responses during the complex process of myocardial wound healing or repair following AMI. This study aimed to investigate the impact of platelet reactivity immediately after primary percutaneous coronary intervention (PCI) on LVR in AMI patients with ST-segment (STEMI) and nonST-segment elevation (NSTEMI). Methods and results This prospective, single-centre, observational study included 182 patients with AMI who underwent primary PCI (107 patient with STEMI and 75 patients with NSTEMI). Patients were administered a loading dose of aspirin plus prasugrel before the procedure, and platelet reactivity was assessed using the VerifyNow P2Y12 assay immediately after PCI. Echocardiography was performed before discharge and during the chronic phase (8 +/- 3 months after discharge). LVR was defined as a relative >= 20% increase in left ventricular end-diastolic volume index (LVEDVI). LVR in chronic phase was found in 34 patients (18.7%) whose platelet reactivity was significantly higher than those without LVR (259.6 +/- 61.5 and 213.1 +/- 74.8 P2Y12 reaction units [PRU]; P = 0.001). The occurrence of LVR did not differ between patients with STEMI and patients with NSTEMI (21.5% and 14.7%; P = 0.33). The optimal cut-off value of platelet reactivity for discriminating LVR was >= 245 PRU. LVEDVI significantly decreased at chronic phase in patients without high platelet reactivity (= d245 PRU) (P = 0.06). Multivariate logistic analysis showed that high platelet reactivity was an independent predictor of LVR after adjusting for LVEDVI before discharge (odds ratio, 4.13; 95% confidence interval, 1.85-9.79). Conclusions High platelet reactivity measured immediately after PCI was a predictor of LVR in patients with AMI during the chronic phase. The role of antiplatelet therapy on inflammation in the myocardium is a promising area for further research

Home-based subcutaneous immunoglobulin after switch from intravenous immunoglobulin improved quality of life in pediatric patient with common variable immunodeficiency: A case report

　Common variable immunodeficiency (CVID) is one of the primary immunodeficiency. Regular immunoglobulin G (IgG) replacement therapy is often performed for patients with CVID.　We experienced a patient who was hospitalized in our hospital for repeated pneumonia and diagnosed CVID at the age of 10 years. He had often been absent from school due to infectious diseases. We were administered intravenous IgG (IVIG) two times and his serum level of IgG became over 1,000 mg/dL. Afterward, he was affected the hand-foot-and-mouth disease one week after discharge. At that time, his IgG level decreased to 751 mg/dL. To maintain stable IgG trough levels, we introduced subcutaneous IgG (SCIG). Since then, his IgG levels remained around 1,000 mg/dL, he has lived without suffering from infectious diseases.　There are some reports that IVIG and SCIG were compared and SCIG was able to obtain a stable IgG trough levels to prevent infection. In addition, because our patient is a mother and child family, it was difficult to visit the outpatient department frequently, so it was desirable to infuse at home.　We experienced a patient who had a stable trough levels with SCIG and improved quality of life, so we report this case with literature reviews

Complete response to pembrolizumab in advanced hepatocellular carcinoma with microsatellite instability

Hepatocellular carcinoma (HCC) has limited systemic treatment options and a poor prognosis. The immune checkpoint inhibitor pembrolizumab was recently approved for the treatment of solid tumors with microsatellite instability (MSI). However, its clinical utility for the management of HCC remains to be clarified. Here, we present a case of unresectable HCC with MSI that showed an impressive response to pembrolizumab treatment. A 64-year-old man with chronic HCV infection was diagnosed with a large HCC. His severe liver dysfunction and poor performance status prevented any treatment option other than sorafenib. However, sorafenib failed after a few days due to the rapid progression of the tumor. Based on the finding of MSI in a biopsy specimen, immunotherapy using pembrolizumab was initiated. A dramatic improvement in his general condition and a reduction in tumor size were observed after the initiation of pembrolizumab treatment. Among a cohort of 50 consecutive patients with advanced HCC who were refractory to standard systemic therapy, MSI was found only in the present case. Immune checkpoint blockade therapy induced prominent anti-tumor effects in HCC with MSI. Screening for defects in DNA mismatch repair function may be warranted in HCC patients despite the low frequency of MSI

Sulfamethoxazole / Trimethoprim confer no change on the clinical course of Kawasaki disease

Kawasaki disease (KD) is one of the most common vasculitis in childhood, but its etiology is still unknown. We hypothesized that Sulfamethoxazole / Trimethoprim (S/T) would inhibit overproduction of cytokine due to heat shock protein produced by intestinal bacteria in patients with KD and improve the clinical course of KD indirectly. We have conducted a prospective study to assess the usefulness of S/T for KD. For patients with KD (S/T group, N=23), we use S/T in addition to the standard treatment in the guidelines such as intravenous immunoglobulin (IVIG) and moderate dose aspirin. The control group (non S/T group, N=32) is patients with KD treated with the standard treatment in the guidelines. The baseline characteristics did not demonstrate notable differences between the two groups. We compare duration of fever, rate of initial IVIG failure, the day of illness membranous desquamation appeared, and the occurrence of coronary artery lesion (CAL) between two groups. Membranous desquamation appeared rather earlier in S/T group than in non S/T group (11.4±3.0 day of illness vs 12.9±3.5 day of illness, P=0.078), but there was no statistically significant difference. Duration of fever (39±59 hours vs 42±57 hours, P=0.41), rate of initial IVIG failure (26% vs 31%, P=0.30), and number of CAL (8.6% vs 9.3%, P=0.87) were found no significant difference between two groups. These data indicated that the use of S/T in acute phase of KD didn\u27t improve any clinical course of KD

Long-term survival with RAS-associated autoimmune leukoproliferative disorder with somatic KRAS mutation:A case report

　RAS -associated autoimmune leukoproliferative disorder (RALD) is a recently reported rare nonmalignant autoimmune disorder. The characteristic clinical findings of RALD include monocytosis, leukocytosis, lymphoproliferation, and autoimmune phenomena. RALD is defined by somatic mutations in KRAS or NRAS . It is a new disease that was reported by Niemela and Takagi in 2011. The prognosis and incidence are currently unknown and the treatment strategy has not yet been established.　Here we describe the long-term survival of a patient with who displayed a somatic KRAS G12D mutation. His clinical features and labolatory data were overlapped with juvenile myelomonocytic leukemia and chronic myelomonocytic leukemia. Mercaptopurine hydrate, hydroxycarbamide and azacitizine were administered to control white blood cell count and improve clinical symptoms. He had a long survival time without hematopoietic stem cell transplantation

Surgical Interventions for Late Aortic Valve Regurgitation Associated with Continuous Flow-Left Ventricular Assist Device Therapy: Experience Gained and Lessons Learned

This study aimed to investigate the outcomes of surgical interventions for symptomatic moderate-to-severe aortic regurgitation (AR), including aortic valve replacement (AVR) and repair (AVP), in 184 patients who underwent continuous flow-left ventricular assist device (Cf-LVAD) implantation as a bridge-to-transplant (BTT) between November 2007 and April 2020. Ten patients (median age, 34 (25–41) years; 60% men) underwent surgical interventions (AVR, n = 6; AVP, n = 4) late after cf-LVAD implantation. The median duration after the device implantation was 34 (24–44) months. Three patients required additional tricuspid valve repair. Aortic valve suturing resulted in severe recurrent AR 6 months postoperatively, due to leaflet cutting in one patient. Seven patients with AVR survived without regurgitation during the study period, except for one non-survivor complicated by liver failure due to postoperative right heart failure. Therefore, six patients after AVP (n = 4) and AVR (n = 2) underwent successful heart transplantation 7 (4–13) months after aortic intervention. Kaplan–Meier analysis showed no significant difference in overall survival through 5 years after cf-LVAD implantation, regardless of the surgical AV intervention chosen (log-rank test, p = 0.86). In conclusion, surgical interventions (AVR or AVP) for patients with an ongoing cf-LVAD are safe, effective, and viable options