638 results match your criteria: "Institute of Statistical Mathematics[Affiliation]"

Chicks make stochastic decisions based on gain rates of different time constants.

Behav Processes

December 2024

Department of Biology, Faculty of Science, Hokkaido University, Sapporo, Japan; Faculty of Pharmaceutical Science, Health Science University of Hokkaido, Tobetsu, Japan; Centre for Mind/Brain Sciences, University of Trento, Rovereto, Italy.

The marginal value theorem (MVT) predicts that optimal foragers leave a patch when the instantaneous gain rate decreases to the average long-term gain rate. However, various animals systematically deviate from this optimum by staying too long or overharvesting relative to this optimum. We hypothesised that animals do not represent their optimal stay time but instead determine their departure point probabilistically.

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Long-term changes in carotid intima-media thickness according to baseline blood pressure level: J-STARS Echo study.

J Neurol Sci

December 2024

Department of Clinical Neuroscience and Therapeutics, Hiroshima University Graduate School of Biomedical and Health Sciences, Hiroshima, Japan; Department of Neurology, Iseikai Hospital, Osaka, Japan.

Background And Aims: We aimed to investigate long-term changes in carotid intima-media thickness (IMT) based on baseline blood pressure (BP) levels in non-cardioembolic stroke patients.

Methods: Patients aged 45-80 years with dyslipidemia who were not on statins before enrollment and had experienced a non-cardioembolic stroke were assigned to either the pravastatin group or the control group in a randomized trial. Patients were classified into three groups according to BP levels: normal BP (N-group: systolic BP [sBP] <140 mmHg and diastolic BP [dBP] <90 mmHg), highly elevated BP (G2 group: sBP ≥160 mmHg or dBP ≥100 mmHg), and mildly elevated BP (G1 group: the remaining patients).

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Estimation of tsunami direction and horizontal velocity field from tsunami magnetic field.

Philos Trans A Math Phys Eng Sci

December 2024

Center for Data Assimilation Research and Applications, Joint Support-Center for Data Science Research, Tachikawa, Japan.

During tsunamis, the interaction between moving seawater and the Earth's magnetic field generates a magnetic field detectable by electromagnetic sensors located on land or on the seafloor. In this study, we introduce new methods for estimating tsunami propagation direction and horizontal velocity fields using tsunami magnetic field data. We derive a transfer function that establishes a relationship between the tsunami magnetic field and the velocity field, emphasizing the alignment between the horizontal magnetic field and the tsunami's propagation direction.

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Quasicrystals are solid-state materials that typically exhibit unique symmetries, such as icosahedral or decagonal diffraction symmetry. They were first discovered in 1984. Over the past four decades of quasicrystal research, around 100 stable quasicrystals have been discovered.

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The relationship between maternal prenatal psychological distress and epilepsy development in offspring has not yet been clarified. Herein, we used a dataset obtained from the Japan Environment and Children's Study, a nationwide birth cohort study, to evaluate the association between six-item Kessler Psychological Distress Scale (K6) scores and epilepsy among 1-3 years old. The data of 97,484 children were retrospectively analyzed.

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Estimating cure proportion in cancer clinical trials using flexible parametric cure models.

BJC Rep

August 2024

Institute of Statistical Mathematics, Tokyo, Japan, and Data Science and AI Innovation Research Promotion Center, Shiga University, Shiga, Japan.

Background: In the context of survival analysis in recent cancer clinical trials, there has been an increasing interest in the proportion of patients who are not susceptible to the event, known as the cure proportion. To estimate it, cure models implicitly specify the time point when patients are considered cured, although the impact of the cure point position on cure proportion estimates is unclear.

Methods: Sensitivity of cure proportion estimates to the knot number and placement in flexible parametric cure models was examined using data from a clinical trial of CheckMate 141, an immuno-oncology compound.

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During large geomagnetic storms, red auroras are typically observed from low-latitude countries such as Japan. The color arises from a specific emission line of oxygen atoms at high altitudes. However, during the May 10-11th 2024 superstorm, magenta auroras were observed above Japan instead of the typical red.

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Introduction: Globally, it is estimated that dietary habits contribute to 22% of adult deaths and 15% of disability-adjusted life years, highlighting the critical role of dietary behaviour in public health. Despite the known benefits of healthy eating, many individuals find it challenging to change their diet for disease prevention. eHealth and mHealth interventions using behaviour change techniques (BCTs) have emerged as promising strategies to address this issue.

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Article Synopsis
  • The article discusses the effectiveness of modified Poisson and least-squares regression analyses for binary outcomes in clinical studies, emphasizing the lack of evidence on their performance in small or sparse data situations.
  • It reveals that while modified Poisson regression can yield biased estimates in these conditions, modified least-squares regression provides unbiased estimates.
  • The authors propose Firth-type penalized methods and an improved robust variance estimator to enhance accuracy and stability in analyzing risk ratios, demonstrating their effectiveness through simulations and an epilepsy study.
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We have successfully proposed and demonstrated a clustering method that overcomes the "needle-in-a-haystack problem" (finding minuscule important regions from massive spectral image data sets). The needle-in-a-haystack problem is of central importance in the characterization of materials since in bulk materials, the properties of a very tiny region often dominate the entire function. To solve this problem, we propose that rational partitioning of the spectral feature space in which spectra are distributed, or defining of the decision boundaries for clustering, can be performed by focusing on the discrimination limit defined by the measurement noise and partitioning the space at intervals of this limit.

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Aim: In this subanalysis of the EXPAND study, we evaluated the risks and benefits of rivaroxaban plus antiplatelet therapy (APT) for patients with non-valvular atrial fibrillation (NVAF) complicated by stable coronary artery disease (CAD), ischemic stroke, or peripheral artery disease (PAD).

Methods: From the EXPAND study population (n=7,141), patients with NVAF complicated by stable CAD (n=886), ischemic stroke (n=1,231), or PAD (n=160) were included. Patients complicated by any of them were set as ALL (n=2,030).

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Background: Internet-based cognitive behavioral therapy (iCBT) shows promise in the prevention of depression. However, the specific iCBT components that contribute to its effectiveness remain unclear.

Objective: We aim to evaluate the effects of iCBT components in preventing depression among university students.

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Erythropoiesis-stimulating agents for preventing acute kidney injury.

Cochrane Database Syst Rev

September 2024

Global Health Nursing, Graduate School of Nursing Science, St. Luke's International University, Tokyo, Japan.

Background: Acute kidney injury (AKI) is characterised by a rapid decline in kidney function and is caused by a variety of clinical conditions. The incidence of AKI in hospitalised adults is high. In animal studies, erythropoiesis-stimulating agents (ESA) have been shown to act as a novel nephroprotective agent against ischaemic, toxic, and septic AKI by inhibiting apoptosis, promoting cell proliferation, and inducing antioxidant and anti-inflammatory responses.

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In observational/field studies, competing risks and left-truncation may co-exist, yielding 'left-truncated competing risks' settings. Under the assumption of independent competing risks, parametric estimation methods were developed for left-truncated competing risks data. However, competing risks may be dependent in real applications.

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Introduction: The use of anti-epileptic drugs (AEDs) in degenerative dementia (DD) remains uncertain. We aimed to evaluate the association of early AED administration with subsequent DD occurrence.

Methods: Using a large nationwide database, we enrolled patients newly diagnosed with epilepsy from 2014 to 2019 ( = 104,225), and using propensity score matching, we divided them into treatment (those prescribed AEDs in 2014) and control groups.

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Nonhuman primates (NHPs) exhibit complex and diverse behavior that typifies advanced cognitive function and social communication, but quantitative and systematical measure of this natural nonverbal processing has been a technical challenge. Specifically, a method is required to automatically segment time series of behavior into elemental motion motifs, much like finding meaningful words in character strings. Here, we propose a solution called SyntacticMotionParser (SMP), a general-purpose unsupervised behavior parsing algorithm using a nonparametric Bayesian model.

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Primates must adapt to changing environments by optimizing their behavior to make beneficial choices. At the core of adaptive behavior is the orbitofrontal cortex (OFC) of the brain, which updates choice value through direct experience or knowledge-based inference. Here, we identify distinct neural circuitry underlying these two separate abilities.

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SoDCoD: a comprehensive database of Cu/Zn superoxide dismutase conformational diversity caused by ALS-linked gene mutations and other perturbations.

Database (Oxford)

August 2024

Laboratory of Cell Signaling, Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.

A structural alteration in copper/zinc superoxide dismutase (SOD1) is one of the common features caused by amyotrophic lateral sclerosis (ALS)-linked mutations. Although a large number of SOD1 variants have been reported in ALS patients, the detailed structural properties of each variant are not well summarized. We present SoDCoD, a database of superoxide dismutase conformational diversity, collecting our comprehensive biochemical analyses of the structural changes in SOD1 caused by ALS-linked gene mutations and other perturbations.

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In the large-scale, prospective, observational JDCP study, a total of 5944 people with type 2 diabetes (mean age at baseline, 61.4 years old; women, 39.9%; and duration of diabetes, 10.

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Temporal effects of lascufloxacin on human gut and salivary microbiota: Analysis using next-generation sequencing method.

J Infect Chemother

July 2024

Division of Infectious Diseases, Faculty of Medicine, Tottori University, Nishi-cho 86, Yonago, Tottori, 683-8503, Japan. Electronic address:

Introduction: Antimicrobial treatment disrupts human microbiota. The effects of lascufloxacin (LSFX), a new fluoroquinolone, on human microbiota remains unknown. Therefore, in this study, we aimed to evaluate the effects of LSFX administration on the gut and salivary microbiota of healthy participants and those with pneumonia.

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Evidence-based medicine (EBM) is helpful for laypersons' decision-making. This study aimed to evaluate the effectiveness of e-learning materials on the essential components of EBM for laypersons. We conducted a web-based, open-label, randomized controlled trial with laypersons in Japan aged ≥20 years who used the internet.

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When conducting database studies, researchers sometimes use an algorithm known as "case definition," "outcome definition," or "computable phenotype" to identify the outcome of interest. Generally, algorithms are created by combining multiple variables and codes, and we need to select the most appropriate one to apply to the database study. Validation studies compare algorithms with the gold standard and calculate indicators such as sensitivity and specificity to assess their validities.

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Death feigning, a state of immobility observed in many animals in response to external stimuli, is an anti-predator behaviour. Although previous studies showed that death-feigning behaviours are quantitative genetic traits, the knowledge of the heritable basis of death-feigning behaviour is lacking. To investigate the heritable basis of death-feigning behaviour, we used 3 laboratory strains of a braconid parasitoid wasp, Heterospilus prosopidis.

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Meta-analysis is an essential tool to comprehensively synthesize and quantitatively evaluate results of multiple clinical studies in evidence-based medicine. In many meta-analyses, the characteristics of some studies might markedly differ from those of the others, and these outlying studies can generate biases and potentially yield misleading results. In this article, we provide effective robust statistical inference methods using generalized likelihoods based on the density power divergence.

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