2,581 research outputs found
The influence of internal corporate governance mechanisms on capital structure decisions of Chinese listed firms
Purpose: This paper examines the effects of internal corporate governance mechanisms on the capital structure decisions of Chinese listed firms.
Design/Methodology: Using a large and more recent dataset consisting of 2386 Chinese listed firms over the period from 1998 to 2012, we employ panel data and use different statistical methods (OLS, fixed effects, and system GMM) to analyse the effects of firm-specific and corporate governance influences on capital structure.
Findings: We find that the proportion of independent directors and ownership concentration exert significant influence on the level of Chinese long-term debt ratios after controlling for firm-specific determinants and split share reforms. Further analysis separating our sample into state-owned enterprises (SOEs) and privately- owned enterprises (POEs) suggests that ownership concentration in the hands of the state leads to decrease in debt ratios.
Implications: The finding implies that concentrated ownership in the hands of the state appears more efficient compared to their private counterparts in their monitoring role.
Original Value: This study extends prior literature, which has concentrated disproportionately on firm-specific influences on capital structure, to the effects of within-firm governance mechanisms on capital structure decisions. The paper contributes to the agency theory-capital structure discourse in an emerging country context where corporate governance system appears weak
Radar array diagnosis from undersampled data using a compressed sensing/sparse recovery technique
A Compressed Sensing/Sparse Recovery approach is adopted in this paper for the accurate diagnosis of fault array elements from undersampled data. Experimental validations on a slotted waveguide test array are discussed to demonstrate the effectiveness of the proposed procedure in the failures retrieval from a small set of measurements with respect to the number of radiating elements. Due to the sparsity feature of the proposed formulation, the method is particularly appealing for the diagnostics of large arrays, typically adopted for radar applications
The Magnetic Distortion Calibration System of the LHCb RICH1 Detector
The LHCb RICH1 detector uses hybrid photon detectors (HPDs) as its optical
sensors. A calibration system has been constructed to provide corrections for
distortions that are primarily due to external magnetic fields. We describe
here the system design, construction, operation and performance.Comment: 9 pages, 14 figure
Aging and oral care: An observational study of characteristics and prevalence of oral diseases in an Italian cohort
Background: Poor oral health is a common condition in patients suffering from dementia. Several aspects of this systemic pathology contribute to causing oral problems: cognitive impairment, behavior disorders, communication and, motor skills deterioration, low levels of cooperation and medical-nursing staff incompetency in the dental field. Objectives: The objectives of this study were to evaluate the prevalence and the characteristics of oral pathology in a demented elderly population, as well as to check the association between the different degree of dementia and the oral health condition of each patient. Materials and Methods: In this observational study (with cross-sectional design) two groups of elderly patients suffering from dementia, living in two different residential care institutions were recruited. The diagnosis of dementia of each included patient was performed using the Clinical Dementia Rating Scale. In order to evaluate the oral health condition of the included subjects, each patient underwent a physical examination of the oral cavity, during which different clinical parameters were analyzed (number of remaining teeth, oral mucosa, periodontal tissues, bone crests). To each parameter, a score was assigned. Spearman’s Rho test was used. Results: Regarding the prevalence of oral pathology in elderly suffering from dementia, it emerged that 20.58% of the included patients had mucosal lesions and/or new mucosal formations (in most cases undiagnosed and therefore untreated). The prevalence of periodontal disease was equal to 82.35% and a marked clinically detectable reabsorption of bone crests was found in almost all patients (88.23%). 24.13% of patients, who underwent the oral examination, had totally edentulous maxillae and/or with retained roots, without prosthetic rehabilitations. The correlation index r showed the presence of a linear correlation (inverse relationship) between the degree of dementia and the state of health of the oral cavity of each patient. Conclusions: Several factors contribute to poor oral health in the elderly suffering from dementia: cognitive functions deterioration, behavioral disorders and inadequate medical-staff nursing training on oral hygiene. This study also demonstrated that the lower the dementia degree is, the lower tends to be the oral health status. In order to guarantee a complete assistance to these patients, residential care institutions should include in their healthcare program specific dental protocols
Increased mitophagy in the skeletal muscle of spinal and bulbar muscular atrophy patients
Spinal and bulbar muscular atrophy (SBMA) is a neuromuscular disorder caused by polyglutamine expansion in the androgen receptor (AR) and characterized by the loss of lower motor neurons. Here we investigated pathological processes occurring in muscle biopsy specimens derived from SBMA patients and, as controls, age-matched healthy subjects and patients suffering from amyotrophic lateral sclerosis (ALS) and neurogenic atrophy. We detected atrophic fibers in the muscle of SBMA, ALS and neurogenic atrophy patients. In addition, SBMA muscle was characterized by the presence of a large number of hypertrophic fibers, with oxidative fibers having a larger size compared with glycolytic fibers. Polyglutamine-expanded AR expression was decreased in whole muscle, yet enriched in the nucleus, and localized to mitochondria. Ultrastructural analysis revealed myofibrillar disorganization and streaming in zones lacking mitochondria and degenerating mitochondria. Using molecular (mtDNA copy number), biochemical (citrate synthase and respiratory chain enzymes) and morphological (dark blue area in nicotinamide adenine dinucleotide-stained muscle cross-sections) analyses, we found a depletion of the mitochondria associated with enhanced mitophagy. Mass spectrometry analysis revealed an increase of phosphatidylethanolamines and phosphatidylserines in mitochondria isolated from SBMA muscles, as well as a 50% depletion of cardiolipin associated with decreased expression of the cardiolipin synthase gene. These observations suggest a causative link between nuclear polyglutamine-expanded AR accumulation, depletion of mitochondrial mass, increased mitophagy and altered mitochondrial membrane composition in SBMA muscle patients. Given the central role of mitochondria in cell bioenergetics, therapeutic approaches toward improving the mitochondrial network are worth considering to support SBMA patients
Theory of mechanical unfolding of homopolymer globule: all-or-none transition in force-clamp mode vs phase coexistence in position-clamp mode
Equilibrium mechanical unfolding of a globule formed by long flexible
homopolymer chain collapsed in a poor solvent and subjected to an extensional
force f (force-clamp mode) or extensional deformation D (position-clamp mode)
is studied theoretically. Our analysis, like all previous analysis of this
problem, shows that the globule behaves essentially differently in two modes of
extension. In the force-clamp mode, mechanical unfolding of the globule with
increasing applied force occurs without intramolecular microphase segregation,
and at certain threshold value of the pulling force the globule unfolds as a
whole ("all-or-none" transition). The value of the threshold force and the
corresponding jump in the distance between the chain ends increase with a
deterioration of the solvent quality and/or with an increase in the degree of
polymerization. In the position-clamp mode, the globule unfolding occurs via
intramolecular microphase coexistence of globular and extended microphases
followed by an abrupt unraveling transition. Reaction force in the microphase
segregation regime demonstrates an "anomalous" decrease with increasing
extension. Comparison of deformation curves in force and position-clamp modes
demonstrates that at weak and strong extensions the curves for two modes
coincide, differences are observed in the intermediate extension range. Another
unfolding scenario is typical for short globules: in both modes of extension
they unfold continuously, without jumps or intramolecular microphase
coexistence, by passing a sequence of uniformly elongated configurations.Comment: 19 pages, 13 figures, 1 tabl
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Short-Term Outcomes After COVID-19-Related Treatment Interruption Among Patients with Neovascular Age-Related Macular Degeneration Receiving Intravitreal Bevacizumab
Purpose: To assess outcomes and recovery strategy of patients undergoing intravitreal injections for exudative age-related macular degeneration who experienced COVID-19 related interruption in treatment during complete lockdown.
Methods: This was a retrospective, observational case study. We used a mixed effect model with random intercepts to evaluate best corrected visual acuity (BCVA) accounting for measured central macular thickness (CMT) and individual variability of each eye. Furthermore, we analysed measures of the pigmented epithelium detachment as well as presence of subretinal fluid and intraretinal cysts.
Results: We included 39 patients and we found a significant reduction in the BCVA between the pre- and post-lockdown controlling for CMT. There was no significant difference in pigmented epithelium detachment and in presence of subretinal fluid and intraretinal cysts.
Conclusion: We detected a significant loss in visual function. The magnitude of the average loss was, however, limited suggesting good efficacy of the recovery strategy
OCT Analysis of Retinal Pigment Epithelium in Myopic Choroidal Neovascularization: Correlation Analysis with Different Treatments
Objective: The objective of this study was to analyze the status of the retinal pigment epithelium (RPE) by means of the spectral domain optical coherence tomography (SD-OCT) overlying the myopic neovascular lesions in the involutive phase, looking for any correlations between the status of the RPE and the size of the lesions and the type and duration of the treatment. Methods: SD-OCT examinations of 83 consecutive patients with myopic choroidal neovascularization (CNV) were reviewed and divided into two groups: group A, patients with CNV characterized by uniformity of the overlying RPE, and group B, patients with CNV characterized by non-uniformity of the overlying RPE. Results: The median lesion area, major diameter, and minimum diameter were, respectively, 0.42 mm2 (0.30–1.01 mm2), 0.76 mm2 (0.54–1.28 mm2), and 0.47 mm2 (0.63–0.77 mm2) in group A, and 1.60 mm2 (0.72–2.67 mm2), 1.76 mm2 (1.13–2.23 mm2), and 0.98 mm2 (0.65–1.33 mm2) in group B. These values were lower in group A than in group B (p < 0.001). The number of treatments with a period free of disease recurrence for at least 6 months was greater (p < 0.010) in group B (6.54 ± 2.82) than in group A (3.67 ± 2.08), and treatments include intravitreal anti-vascular endothelial growth factor injection, photodynamic therapy, or both. Conclusions: Our results showed that the size of myopic neovascular lesion influences the development of a uniform RPE above the lesion and therefore the disease prognosis. The presence of uniform RPE was found to be extremely important in the follow-up of patients with myopic CNV, as it influences the duration of the disease and the number of treatments required
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