Improving imbalanced classification using near-miss instances

The class imbalance is a major issue in classification, i.e., the sample size of a rare class (positive) is often a performance bottleneck. In real-world situations, however, “near-miss” positive instances, i.e., negative but nearly-positive instances, are sometimes plentiful. For example, natural disasters such as floods are rare, while there are relatively plentiful near-miss cases where actual floods did not occur but the water level approached the bank height. We show that even when the true positive cases are quite limited, such as in disaster forecasting, the accuracy can be improved by obtaining refined label-like side-information “positivity” (e.g., the water level of the river) to distinguish near-miss cases from other negatives. Conventional cost-sensitive classification cannot utilize such side-information, and the small size of the positive sample causes high estimation variance. Our approach is in line with learning using privileged information (LUPI), which exploits side-information for training without predicting the side-information itself. We theoretically prove that our method reduces the estimation variance, provided that near-miss positive instances are plentiful, in exchange for additional bias. Results of extensive experiments demonstrate that our method tends to outperform or compares favorably to existing approaches

Tumefactive multiple sclerosis requiring emergent biopsy and histological investigation to confirm the diagnosis: a case report

<p>Abstract</p> <p>Introduction</p> <p>Tumefactive multiple sclerosis is a demyelinating disease that demonstrates tumor-like features on magnetic resonance imaging. Although diagnostic challenges without biopsy have been tried by employing radiological studies and cerebrospinal fluid examinations, histological investigation is still necessary for certain diagnosis in some complicated cases.</p> <p>Case presentation</p> <p>A 37-year-old Asian man complaining of mild left leg motor weakness visited our clinic. Magnetic resonance imaging demonstrated high-signal lesions in bilateral occipital forceps majors, the left caudate head, and the left semicentral ovale on fluid-attenuated inversion recovery and T2-weighted imaging, and these lesions were enhanced by gadolinium-dimeglumin. Tumefactive multiple sclerosis was suspected because the enhancement indistinctly extended along the corpus callosum on magnetic resonance imaging and scintigraphy showed a low malignancy of the lesions. But oligoclonal bands were not detected in cerebrospinal fluid. In a few days, his symptoms fulminantly deteriorated with mental confusion and left hemiparesis, and steroid pulse therapy was performed. In spite of the treatment, follow-up magnetic resonance imaging showed enlargement of the lesions. Therefore, emergent biopsy was performed and finally led to the diagnosis of demyelinating disease. The enhanced lesion on magnetic resonance imaging disappeared after one month of prednisolone treatment, but mild disorientation and left hemiparesis remained as sequelae.</p> <p>Conclusions</p> <p>Fulminant aggravation of the disease can cause irreversible neurological deficits. Thus, an early decision to perform a biopsy is necessary for exact diagnosis and appropriate treatment if radiological studies and cerebrospinal fluid examinations cannot rule out the possibility of brain tumors.</p

Changes in Plasma Clozapine Levels after Smoking Cessation in Japanese Inpatients with Schizophrenia: A Retrospective Cohort Study

Although reported for Caucasians, changes in plasma clozapine levels after smoking cessation in East Asians remain unclear. We here investigated plasma clozapine levels before and after smoking cessation in Japanese inpatients with schizophrenia. We conducted a retrospective chart review of 14 inpatients with schizophrenia who were being treated with clozapine between June 1, 2019, and July 31, 2019 and who were smokers as of July 1, 2019, the day on which a smoking ban was instituted in the tertiary public psychiatric hospital. The primary outcome was individual differences in plasma clozapine levels between before and after the smoking ban, which were compared using paired t-tests. The mean plasma clozapine level was significantly increased, by 213.4 ng/mL (95% CI 119.9-306.8; p<0.01) or 53.2%. Four of the 14 inpatients experienced clinically significant side effects, such as myoclonus, drooling, and amnesia, due to the development of high plasma clozapine levels. Our findings indicated that close monitoring of plasma clozapine levels before and after smoking cessation and prior dose adjustment of clozapine may be necessary, to prevent a significant risk of developing high plasma clozapine levels, even in Japanese patients

Validity and Reliability of the Japanese Version of the 12-item Self-administered World Health Organization Disability Assessment Schedule (WHODAS) 2.0 in Patients with Schizophrenia

It is necessary to assess functional impairment when treating schizophrenia. The World Health Organization Disability Assessment Schedule 2.0 (WHODAS 2.0) has been adopted as a measure of functional disability in the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition. This study was a secondary analysis from a cross-sectional study of health-related behaviors among patients with schizophrenia. We examined the validity and reliability of the Japanese version of the 12-item WHODAS 2.0 when self-administered by such patients. Participants were 350 outpatients with schizophrenia from a psychiatric hospital. The standard six-factor structure of the WHODAS 2.0 showed a good fit for these participants. The Cronbach’s alpha coefficient was 0.858, showing good internal consistency. The WHODAS 2.0 showed moderate correlations with the modified Global Assessment of Functioning and Kessler 6 scales (r=−0.434 and 0.555, respectively). The results of this study show that the Japanese version of the 12-item self-administered WHODAS 2.0 has good internal consistency and convergent validity among patients with schizophrenia. Further exploration of the usefulness of WHODAS 2.0 in clinical settings is needed

Patients' acceptability and implementation outcomes of a case management approach to encourage participation in colorectal cancer screening for people with schizophrenia: a qualitative secondary analysis of a mixed-method randomised clinical trial

Objectives We examined the efficacy of case management (CM) interventions to encourage participation in colorectal cancer screening for patients with schizophrenia. This study aimed to clarify patients' acceptability of the intervention and the helpful components of the intervention. Simultaneously, the study aimed to determine the acceptability, appropriateness and feasibility of the intervention from the perspective of psychiatric care providers. Study design and setting This study was a secondary qualitative analysis of a mixed-method randomised controlled trial that evaluated the efficacy of the CM approach to encourage participation in cancer screening for people with schizophrenia. The intervention comprised education and patient navigation for colorectal cancer screening. Interviews were conducted with patients who received the intervention and staff from two psychiatric hospitals in Japan who delivered the intervention. Participants Of the 172 patients with schizophrenia who participated in the trial, 153 were included. In addition, three out of six providers were included. Data collection and analysis Using a structured interview, the case manager asked participants about patient acceptability and the helpful components of the intervention. Content analysis was conducted for the responses obtained, and the number of responses was tabulated by two researchers. For the interviews with the providers, opinions obtained from verbatim transcripts were extracted and summarised. Results Forty-three of the 56 patients perceived that the intervention was acceptable. For the intervention component, inperson counselling with an explanation of the screening process by psychiatric care providers was most frequently reported by the patients as helpful (48 of the 68 respondents). Psychiatric care providers evaluated the intervention as acceptable, appropriate and easy to understand and administer. However, providing the intervention to all patients simultaneously was considered difficult with the current human resources. Conclusions This study showed that the CM intervention was perceived as acceptable by patients and acceptable and appropriate by psychiatric care providers

Prey preference in a kleptoplastic dinoflagellate is linked to photosynthetic performance

Dinoflagellates of the family Kryptoperidiniaceae, known as “dinotoms”, possess diatom-derived endosymbionts and contain individuals at three successive evolutionary stages: a transiently maintained kleptoplastic stage; a stage containing multiple permanently maintained diatom endosymbionts; and a further permanent stage containing a single diatom endosymbiont. Kleptoplastic dinotoms were discovered only recently, in Durinskia capensis; until now it has not been investigated kleptoplastic behavior and the metabolic and genetic integration of host and prey. Here, we show D. capensis is able to use various diatom species as kleptoplastids and exhibits different photosynthetic capacities depending on the diatom species. This is in contrast with the prey diatoms in their free-living stage, as there are no differences in their photosynthetic capacities. Complete photosynthesis including both the light reactions and the Calvin cycle remain active only when D. capensis feeds on its habitual associate, the “essential” diatom Nitzschia captiva. The organelles of another edible diatom, N. inconspicua, are preserved intact after ingestion by D. capensis and expresses the psbC gene of the photosynthetic light reaction, while RuBisCO gene expression is lost. Our results indicate that edible but non-essential, “supplemental” diatoms are used by D. capensis for producing ATP and NADPH, but not for carbon fixation. D. capensis has established a species-specifically designed metabolic system allowing carbon fixation to be performed only by its essential diatoms. The ability of D. capensis to ingest supplemental diatoms as kleptoplastids may be a flexible ecological strategy, to use these diatoms as “emergency supplies” while no essential diatoms are available.Open Access funding enabled and organized by Projekt DEAL.We are grateful to Dr Benjamin Bailleul for discussing the photoactivity possibility of N. inconspicua, and to Prof Dieter Spiteller and Dr Adrien Lapointe for suggesting the feeding experiment of D. capensis with four selected diatoms. We also thank Dr Martin Stöckl, from the Bioimaging Centre at University of Konstanz, for technical support of the CLSM. Our thanks also go to Ms Selina Pucher and Mr Alexander H. Fürst for discussing the RT-qPCR data analyses and evaluation, and to Mr Niccolo Mosesso for discussing the TEM protocol improvement. This research was supported by the Bridging Stipend of University of Konstanz (No.638/20, granted to NY), the DFG Research Grant (No. YA 577/2-1, granted to NY), and the Symbiosis Model Systems Award (No. GBMF9360, granted to NY, RT, DGM, PGK) of the Gordon and Betty Moore Foundation. The CERCA Programme of Generalitat of Catalonia is also acknowledged. The Royal Botanic Garden Edinburgh is supported by the Scottish Government’s Rural and Environment Science and Analytical Services Division.info:eu-repo/semantics/publishedVersio

Cell-Surface Protein Profiling Identifies Distinctive Markers of Progenitor Cells in Human Skeletal Muscle

SummarySkeletal muscle contains two distinct stem/progenitor populations. One is the satellite cell, which acts as a muscle stem cell, and the other is the mesenchymal progenitor, which contributes to muscle pathogeneses such as fat infiltration and fibrosis. Detailed and accurate characterization of these progenitors in humans remains elusive. Here, we performed comprehensive cell-surface protein profiling of the two progenitor populations residing in human skeletal muscle and identified three previously unrecognized markers: CD82 and CD318 for satellite cells and CD201 for mesenchymal progenitors. These markers distinguish myogenic and mesenchymal progenitors, and enable efficient isolation of the two types of progenitors. Functional study revealed that CD82 ensures expansion and preservation of myogenic progenitors by suppressing excessive differentiation, and CD201 signaling favors adipogenesis of mesenchymal progenitors. Thus, cell-surface proteins identified here are not only useful markers but also functionally important molecules, and provide valuable insight into human muscle biology and diseases

Robust Association Tests Under Different Genetic Models, Allowing for Binary or Quantitative Traits and Covariates

The association of genetic variants with outcomes is usually assessed under an additive model, for example by the trend test. However, misspecification of the genetic model will lead to a reduction in power. More robust tests for association might therefore be preferred. A useful approach is to consider the maximum of the three test statistics under additive, dominant and recessive models (MAX3). The p-value however has to be adjusted to maintain the type I error rate. Previous studies and software on robust association tests have focused on binary traits without covariates. In this study we developed an analytic approach to robust association tests using MAX3, allowing for quantitative or binary traits as well as covariates. The p-values from our theoretical calculations match very well with those from a bootstrap resampling procedure. The methodology is implemented in the R package RobustSNP which is able to handle both small-scale studies and GWAS. The package and documentation are available at http://sites.google.com/site/honcheongso/software/robustsnp