Applications of Monte Carlo Methods in Statistical Inference Using Regression Analysis

This paper studies the use of Monte Carlo simulation techniques in the field of econometrics, specifically statistical inference. First, I examine several estimators by deriving properties explicitly and generate their distributions through simulations. Here, simulations are used to illustrate and support the analytical results. Then, I look at test statistics where derivations are costly because of the sensitivity of their critical values to the data generating processes. Simulations here establish significance and necessity for drawing statistical inference. Overall, the paper examines when and how simulations are needed in studying econometric theories

Serial Magnetic Resonance Imagings of Multiple Brain Abscesses in a Patient with Pneumococcal Meningoencephalitis

We report a 43-yr-old man manifesting bacterial meningoencephalitis and multiple abscesses by Streptococcus pneumoniae. Serial magnetic resonance (MR) imagings and MR spectroscopy showed the evolution of multiple brain abscesses over 4 weeks: the enhanced rings became thicker and the dimension of whole lesions larger despite shrinkage of the ring-enhanced regions. These findings may be evidence of active inflammation working to sequestrate the lesion and protect the surrounding normal brain parenchyma from additional damage, even in the final stage of the brain abscess

Influence of Mg Deficiency on the Superconductivity in MgB2 Thin Films Grown by using HPCVD

The effects of Mg deficiency in MgB2 films grown by using hybrid physical-chemical vapor deposition were investigated after vacuum annealing at various temperatures. High-quality MgB2 films grown on c-cut Al2O3 substrates with different superconducting transition temperatures (Tc) of 40.2 and 41 K were used in this study. As the annealing temperature was increased from 200 to 800 C, the Mg contents in the MgB2 films systemically decreased, but the Tc's did not change, within 0.12 K, until the annealing temperature reached 700 C. For MgB2 films annealed at 800 C for 30 min, however, no superconductivity was observed, and the temperature dependence of the resistivity showed a semiconducting behavior. We also found that the residual resistivity ratio decreased with increasing annealing temperature.Comment: 7 pages including 4 figure

Premorbid Clinical Frailty Score and 30‐day mortality among older adults in the emergency department

Objectives: The association between frailty and short-term prognosis has not been established in critically ill older adults presenting to the emergency department. We sought to examine the association between premorbid frailty and 30-day mortality in this patient population. Methods: This is a retrospective observational study on older adults aged over 75 who were triaged as Level 1 resuscitation with subsequent admissions to intermediate units or intensive care units (ICUs) in a single critical care center, from January to December 2019. We excluded patients with out-of-hospital cardiac arrest or those transferred from other hospitals. Frailty was evaluated by the Clinical Frailty Scale (CFS) from the patients' chart reviews. The primary outcome was 30-day mortality, and we examined the association between frailty scored on the CFS and 30-day mortality using a multivariable logistic regression model with CFS 1-4 as a reference. Results: A total of 544 patients, median age: 82 years (interquartile rang 78 to 87), were included in the study. Of these, 29% were in shock and 33% were in respiratory failure. The overall 30-day mortality was 15.1%. The adjusted risk difference (95% confidence interval [CI]) in mortality for CFS 5, CFS 6, and CFS 7-9 was 6.3% (-3.4 to 15.9), 11.2% (0.4 to 22.0), and 17.7% (5.3 to 30.1), respectively; and the adjusted risk ratio (95% CI) was 1.45 (0.87 to 2.41), 1.85 (1.13 to 3.03), and 2.44 (1.50 to 3.96), respectively. Conclusion: The risk of 30-day mortality increased as frailty advanced in critically ill older adults. Given this high risk of short-term outcomes, ED clinicians should consider goals of care conversations carefully to avoid unwanted medical care for these patients

Non-Hodgkin's lymphoma of the sphenoid sinus presenting as isolated oculomotor nerve palsy

BACKGROUND: Solitary involvement of the sphenoid sinus has rarely been reported in non-Hodgkin's lymphoma. Isolated oculomotor nerve palsy is uncommon as an initial presentation of malignant tumors of the sphenoid sinus. CASE PRESENTATION: A 53-year-old woman presented with a three-month history of headache and diplopia. Neurological examination revealed complete left oculomotor nerve palsy. Magnetic Resonance Imaging (MRI) demonstrated a homogenous soft-tissue lesion occupying the left sphenoid sinus and invading the left cavernous sinus. The patient underwent transsphenoidal biopsy and the lesion was histologically diagnosed as non-Hodgkin's lymphoma, diffuse large B-cell type. Tumor cells were positive for CD20 and negative for CD3. Following six cycles of chemotherapy, the left oculomotor nerve palsy that had been previously observed was completely resolved. There was no enhancing lesion noted on follow-up MRI. CONCLUSION: It is important to recognize that non-Hodgkin's lymphoma of the sphenoid sinus can present with isolated oculomotor nerve palsy, although it is extremely rare. The cranial nerve deficits can resolve dramatically after chemotherapy.ope

Epileptic nystagmus: A case report and systematic review

AbstractPurposeWe aimed to define the characteristics of epileptic nystagmus and correlate those with other clinical findings in a large number of patients.MethodsWe report a patient with epileptic nystagmus and additionally reviewed the reported clinical features of 36 more patients through a systematic literature search. We analyzed the characteristics of epileptic nystagmus and attempted correlations of those with alertness of the patients and epileptic foci on EEG.ResultsAll 33 patients with unilateral horizontal nystagmus showed nystagmus beating away from the side of ictal discharges. Epileptic nystagmus was preceded by gaze deviation in 21 patients, with contraversive in 19 and ipsiversive in 2. Seizures associated with epileptic nystagmus were mostly focal (25/29, 86.2%) with or without loss of awareness. Ictal discharges originated from the occipital (n=16), parietal (n=9), temporo-occipital (n=6), frontal (n=4), and temporal (n=3) areas, and two patients had multiple epileptic foci. Seizures were usually symptomatic (24/37, 64.9%). The presence of preceding gaze deviation and midline crossing of the nystagmus did not correlate with the ictal onset zone or alertness of the patients. Recording of epileptic nystagmus was available only in 6 patients, and the epileptic nystagmus could be localized to the saccadic areas in two and to the smooth pursuit areas in another two. Two patients showed the features of epileptic nystagmus from both areas.ConclusionEven though the localizing value of epileptic nystagmus seems limited in previous reports, the fast phase of epileptic nystagmus was almost always directed away from the epileptic focus that mostly arose from the posterior part of the cerebral hemisphere

Effects of Mental Health Support on the Grief of Bereaved People Caused by Sewol Ferry Accident

Few studies have assessed the overall effects of multi-centered, complicated mental health support on the grief process. This study investigated the broader influence of mental health support provided practically to the bereaved family on the severity of complicated grief. Ninety-three bereaved family members of the Sewol ferry accident were recruited. Severity of complicated grief, post-traumatic stress disorder (PTSD) and depressive disorder was assessed through self-reporting questionnaire, inventory of complicated grief (ICG), PTSD Check List-5 (PCL-5) and Patient Health Questionnaire-9 (PHQ-9). We also included demographic, socioeconomic, health-related variables, and Functional Social Support Questionnaire (FSSQ), which affect the ICG score. Participants were divided into 4 groups based on the experience of psychotherapy or psychiatry clinic service before the accident and mental health support after the disaster. In univariate analysis, these 4 groups showed a significant difference in the mean ICG score (P=0.020). Participants who received mental health support only after the Sewol ferry accident (group 2) showed a lower mean ICG score than those who received neither psychotherapy or psychiatry clinic service before the disaster nor mental health support after the accident (group 4). There was no significant correlation between the ICG score and other variables except for subjective health status measured 1 month after the disaster (P=0.005). There was no significant difference in PCL-5 (P=0.140) and PHQ-9 scores (P=0.603) among groups, respectively. In conclusion, mental health support significantly reduced the severity of grief only in those participants who had not received any psychotherapy or psychiatry clinic service before the accident

Indoleamine 2,3-dioxygenase (IDO) is frequently expressed in stromal cells of Hodgkin lymphoma and is associated with adverse clinical features: a retrospective cohort study

Background: Regulation of tumor microenvironment is closely involved in the prognosis of Hodgkin lymphoma (HL). Indoleamine 2,3-dioxygenase (IDO) is an enzyme acting as immune modulator through suppression of T-cell immunity. This study aims to investigate role of IDO in the microenvironment of HL. Methods: A total of 121 cases of HL were enrolled to do immunohistochemistry for IDO, CD163, CD68, CD4, CD8, and FoxP3. Positivity was evaluated from area fractions or numbers of positive cells using automated image analyzer. Correlations between IDO expression and various cellular infiltrates and clinicopathologic parameters were examined and survival analyses were performed. Results: IDO was expressed in histiocytes, dendritic cells and some endothelial cells with variable degrees, but not in tumor cells. IDO positive cells were more frequently found in mixed cellularity type than other histologic types, and in cases with EBV+, high Ann Arbor stages, B symptoms, and high IPS (all p < 0.05). High IDO expression was associated with inferior survival (p < 0.001) and reflects an independent prognostic factor in nodular sclerosis HL. Conclusions: This is the first study suggesting that IDO is the principle immunomodulator and is involved to adverse clinical outcomes of HL.Peer Reviewe