214 research outputs found
A Probabilistic Higher-Order Fixpoint Logic
We introduce PHFL, a probabilistic extension of higher-order fixpoint logic,
which can also be regarded as a higher-order extension of probabilistic
temporal logics such as PCTL and the -calculus. We show that PHFL is
strictly more expressive than the -calculus, and that the PHFL
model-checking problem for finite Markov chains is undecidable even for the
-only, order-1 fragment of PHFL. Furthermore the full PHFL is far more
expressive: we give a translation from Lubarsky's -arithmetic to PHFL,
which implies that PHFL model checking is -hard and -hard.
As a positive result, we characterize a decidable fragment of the PHFL
model-checking problems using a novel type system
A Probabilistic Higher-order Fixpoint Logic
We introduce PHFL, a probabilistic extension of higher-order fixpoint logic,
which can also be regarded as a higher-order extension of probabilistic
temporal logics such as PCTL and the -calculus. We show that PHFL is
strictly more expressive than the -calculus, and that the PHFL
model-checking problem for finite Markov chains is undecidable even for the
-only, order-1 fragment of PHFL. Furthermore the full PHFL is far more
expressive: we give a translation from Lubarsky's -arithmetic to PHFL,
which implies that PHFL model checking is -hard and -hard.
As a positive result, we characterize a decidable fragment of the PHFL
model-checking problems using a novel type system
MeV protons in the inner belt and slot region observed by HEP onboard the Arase satellite
The Tenth Symposium on Polar Science/Ordinary sessions: [OS] Space and upper atmospheric sciences, Wed. 4 Dec. /Entrance Hall (1st floor) at National Institute of Polar Research (NIPR
Wideband digital frequency detector with subtraction-based phase comparator for frequency modulation atomic force microscopy
金沢大学フロンティアサイエンス機構We have developed a wideband digital frequency detector for high-speed frequency modulation atomic force microscopy (FM-AFM). We used a subtraction-based phase comparator (PC) in a phase-locked loop circuit instead of a commonly used multiplication-based PC, which has enhanced the detection bandwidth to 100 kHz. The quantitative analysis of the noise performance revealed that the internal noise from the developed detector is small enough to provide the theoretically limited noise performance in FM-AFM experiments in liquid. FM-AFM imaging of mica in liquid was performed with the developed detector, showing its stability and applicability to true atomic-resolution imaging in liquid. © 2009 American Institute of Physics
In Vivo Imaging of Septic Encephalopathy
Septic encephalopathy is a devastating symptom of severe sepsis. Many studies have been performed to uncover the pathophysiological mechanisms of septic encephalopathy; however, novel technical approaches are still required to overcome this complex symptom. Because patients are suffering from severe cognitive impairment, coma, or delirium, which burden not only patients but also caregivers, overcoming septic encephalopathy is still a major social problem worldwide, especially in the intensive care. Septic encephalopathy seems to be caused by cytokine invasion and/or oxidative stress into the brain, and this pathological state leads to imbalance of neurotransmitters. In addition to this pathophysiology, septic encephalopathy causes complicated symptoms (e.g., ischemic stroke, edema, and aberrant sensory function). For these pathophysiological mechanisms, electrophysiology using animal models, positron emission tomography (PET), computed tomography, and magnetic resonance imaging for septic patients has provided important clues. However, the research for septic encephalopathy is currently confronted with the difficulty of complex symptoms. To overcome this situation, in this chapter, we introduce our novel methods for in vivo imaging of septic encephalopathy using near infrared (NIR) nanoparticles, quantum dots. In addition to our recent progress, we propose a strategy for the future approach to in vivo imaging of septic encephalopathy
Detecting immunoglobulin G4-related intracranial arteriopathy with magnetic resonance vessel wall imaging: a preliminary experience in two cases
[Background] Detecting immunoglobulin G4 (IgG4)-related intracranial arteriopathy, a rare neurovascular complication of IgG4-related disease, is challenging. While magnetic resonance (MR) vessel wall imaging (VWI) can visualize various neurovascular pathologies, its application to this arteriopathy has not been reported as of this writing. [Case presentation] A 74-year-old male and a 65-year-old female manifested multiple cranial nerve palsy and neck pain, respectively. Both cases exhibited multiorgan masses with markedly elevated serum IgG4 levels and were clinically diagnosed with IgG4-related disease. Three-dimensional T1-weighted black blood VWI with and without contrast agent identified intracranial vascular lesions characterized as nearly-circumferential mural thickening with homogeneous contrast enhancement in the internal carotid and vertebral arteries; some of the lesions had been unrecognized with screening MR angiography due to expansive remodeling. The former patient underwent corticosteroid therapy, and VWI after treatment revealed decreased mural thickening and enhancement. [Conclusion] Further studies to elucidate characteristic findings of VWI might contribute to early detection of this treatable pathology
Wideband digital frequency detector with subtraction-based phase comparator for frequency modulation atomic force microscopy
Increased osteocyte apoptosis during the development of femoral head osteonecrosis in spontaneously hypertensive rats.
We investigated the presence of osteocyte apoptosis in the necrotic trabeculae of the femoral head of spontaneously hypertensive rat (SHR) using the in situ nick end labeling (TUNEL) method and transmission electron microscopy. The occurrence of osteonecrosis and ossification disturbance was significantly higher in SHR compared with Wistar Kyoto (WKY) rats, and Wistar (WT) rats used as control animals (P < 0.01). A high population of TUNEL positive osteocytes was detected mainly in 10- and 15-week-old SHRs. Sectioned examination of the femoral head of SHRs and WKY rats by electron microscopy revealed apoptotic cell appearances such as aggregation of chromatin particles and lipid formation. In contrast, a positive reaction was significantly lower in osteocytes in the femoral heads of WT rats (P < 0.01). Our results indicate that apoptosis forms an important component of the global pathologic process affecting the femoral head of SHR, which leads to osteonecrosis in this region.</p
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