88 research outputs found

    On the decomposition of stochastic discounted cash flows

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    This paper extends previous results by Peccati [7] and Beccacece [1] on the decomposition of the discounted cash flow for deterministic financial operations to the stochastic case. Modelling financial operations as processes whose cumulant is a semimartingale, we obtain a very general decomposition formula which allows one to consider even random discount factors. © 1991 Springer-Verlag

    Perspectives about living on the horns of dilemmas: An analysis of gender factors related to superintendent decision-making and problem-solving

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    The major focus of this paper is a gender-based analysis of school superintendent decision-making and problem-solving as well as an investigation of contemporary leadership dilemmas. The findings are based on responses from 258 superintendents of K-12 school districts in Delaware, Maryland, New Jersey, New York, and Pennsylvania collected over a period of three years (2009-2011). The researchers also conducted 18 comprehensive qualitative “face-to-face” interviews with self-selected superintendents who responded to the quantitative survey. The intended outcome of this article is for education policy makers, professors, and practitioners to comprehensively examine the extent and degree of various dilemmas confronting the Mid-Atlantic Region school superintendent sample and to evaluate the decision-making and problem-solving approaches used by them. The study results that are presented will serve as valuable references to not only individual superintendents but also to university administrator preparation professors and to state administrator licensure agencies because it is important for all aspiring superintendents to know the various issues associated with education leadership and the personal and professional dilemmas that they need to be prepared to face as they embark on a career to improve schooling in the United States

    Peripheral blood-derived mesenchymal stem cells demonstrate immunomodulatory potential for therapeutic use in horses

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    Previously, we showed that mesenchymal stem cells (MSC) can be mobilized into peripheral blood using electroacupuncture (EA) at acupoints, LI-4, LI-11, GV-14, and GV-20. The purpose of this study was to determine whether EA-mobilized MSC could be harvested and expanded in vitro to be used as an autologous cell therapy in horses. Peripheral blood mononuclear cells (PBMC) isolated from young and aged lame horses (n = 29) showed a marked enrichment for MSCs. MSC were expanded in vitro (n = 25) and administered intravenously at a dose of 50 x 106 (n = 24). Treatment resulted in significant improvement in lameness as assessed by the American Association of Equine Practitioners (AAEP) lameness scale (n = 23). MSCs exhibited immunomodulatory function by inhibition of lymphocyte proliferation and induction of IL-10. Intradermal testing showed no immediate or delayed immune reactions to MSC (1 x 106 to 1 x 104). In this study, we demonstrated an efficient, safe and reproducible method to mobilize and expand, in vitro, MSCs in sufficiently high concentrations for therapeutic administration. We confirm the immunomodulatory function of these cells in vitro. This non-pharmacological and non-surgical strategy for stem cell harvest has a broad range of biomedical applications and represents an improved clinically translatable and economical cell source for humans

    Use of Telemedicine Healthcare Systems in Children and Adolescents with Chronic Disease or in Transition Stages of Life: Consensus Document of the Italian Society of Telemedicine (SIT), of the Italian Society of Preventive and Social Pediatrics (SIPPS), of the Italian Society of Pediatric Primary Care (SICuPP), of the Italian Federation of Pediatric Doctors (FIMP) and of the Syndicate of Family Pediatrician Doctors (SIMPeF)

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    Telemedicine is considered an excellent tool to support the daily and traditional practice of the health profession, especially when referring to the care and management of chronic patients. In a panorama in which chronic pathologies with childhood onset are constantly increasing and the improvement of treatments has allowed survival for them into adulthood, telemedicine and remote assistance are today considered effective and convenient solutions both for the chronic patient, who thus receives personalized and timely assistance, and for the doctors, who reduce the need for direct intervention, hospitalizations and consequent management costs. This Consensus document, written by the main Italian Scientific Societies involved in the use of telemedicine in pediatrics, has the objectives to propose an organizational model based on the relationships between the actors who participate in the provision of a telemedicine service aimed at minors with chronic pathologies, identifying specific project links between the areas of telemedicine in the developmental age from the first 1000 days of life to the age adult. The future scenario will have to be able to integrate digital innovation in order to offer the best care to patients and citizens. It will have to be able to provide the involvement of patients from the very beginning of the design of any care pathway, increasing where possible the proximity of the health service to citizens

    Burnout syndrome in Cypriot physiotherapists: a national survey

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    Background. Burnout in the healthcare workers is formally defined as a state of physical, emotional and mental exhaustion caused by long-term involvement in situations that are emotionally demanding. Methods. Using a random stratified sampling method and taking into account geographical location, specialty and type of employment, 172 physiotherapists working both in the private and public sectors completed an anonymous questionnaire that included several aspects related to burnout; the MBI scale, questions related to occupational stress, and questions pertaining to self image. Results. Almost half (46%) of the 172 participants believed that their job is stressful. Approximately 57% of the physiotherapists who worked in the public sector and 40% of those who worked in the private sector (p = 0.038) reported that their job is stressful. In total, 21.1% of participants met Maslach's criteria for burnout. The point prevalence of burnout was as follows: (1) 13.8% of those who worked in the public sector and 25.5% of those in the private sector (2) 22.2% of males and 20% of females (3) 21.6% who were married, 18% who were single and 33.3% who were separated. Gender was found to be associated with the level of personal accomplishment (chi-squared test; p = 0.049), as 17.8% of men compared with 24.3% of women reported high personal accomplishment. The number of years of working as a physiotherapist correlated negatively (r = -0.229, p = 0.004) with the total depersonalization score. Regression analysis showed that the perception that the job is stressful (p < 0.001) and the low salary (p = 0.016) were significant predictors of high emotional exhaustion scores, while age group (p = 0.027) predicted high scores of depersonalization and the employment sector (p = 0.050) as well as the low salary predicted high personal accomplishment scores. Conclusions. Burnout levels in physiotherapists in Cyprus ranged from low to moderate

    Prostaglandin E2 Promotes Endothelial Differentiation from Bone Marrow-Derived Cells through AMPK Activation

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    Prostaglandin E2 (PGE2) has been reported to modulate angiogenesis, the process of new blood vessel formation, by promoting proliferation, migration and tube formation of endothelial cells. Endothelial progenitor cells are known as a subset of circulating bone marrow mononuclear cells that have the capacity to differentiate into endothelial cells. However, the mechanism underlying the stimulatory effects of PGE2 and its specific receptors on bone marrow-derived cells (BMCs) in angiogenesis has not been fully characterized. Treatment with PGE2 significantly increased the differentiation and migration of BMCs. Also, the markers of differentiation to endothelial cells, CD31 and von Willebrand factor, and the genes associated with migration, matrix metalloproteinases 2 and 9, were significantly upregulated. This upregulation was abolished by dominant-negative AMP-activated protein kinase (AMPK) and AMPK inhibitor but not protein kinase, a inhibitor. As a functional consequence of differentiation and migration, the tube formation of BMCs was reinforced. Along with altered BMCs functions, phosphorylation and activation of AMPK and endothelial nitric oxide synthase, the target of activated AMPK, were both increased which could be blocked by EP4 blocking peptide and simulated by the agonist of EP4 but not EP1, EP2 or EP3. The pro-angiogenic role of PGE2 could be repressed by EP4 blocking peptide and retarded in EP4+/− mice. Therefore, by promoting the differentiation and migration of BMCs, PGE2 reinforced their neovascularization by binding to the receptor of EP4 in an AMPK-dependent manner. PGE2 may have clinical value in ischemic heart disease

    Coaction of Spheroid-Derived Stem-Like Cells and Endothelial Progenitor Cells Promotes Development of Colon Cancer

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    Although some studies described the characteristics of colon cancer stem cells (CSCs) and the role of endothelial progenitor cells (EPCs) in neovascularization, it is still controversial whether an interaction exists or not between CSCs and EPCs. In the present study, HCT116 and HT29 sphere models, which are known to be the cells enriching CSCs, were established to investigate the roles of this interaction in development and metastasis of colon cancer. Compared with their parental counterparts, spheroid cells demonstrated higher capacity of invasion, higher tumorigenic and metastatic potential. Then the in vitro and in vivo relationship between CSCs and EPCs were studied by using capillary tube formation assay and xenograft models. Our results showed that spheroid cells could promote the proliferation, migration and tube formation of EPCs through secretion of vascular endothelial growth factor (VEGF). Meanwhile, the EPCs could increase tumorigenic capacity of spheroid cells through angiogenesis. Furthermore, higher microvessel density was detected in the area enriching cancer stem cells in human colon cancer tissue. Our findings indicate that spheroid cells possess the characteristics of cancer stem cells, and the coaction of CSCs and EPCs may play an important role in the development of colon cancer

    Placenta Growth Factor-1 Exerts Time-Dependent Stabilization of Adherens Junctions Following VEGF-Induced Vascular Permeability

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    Increased vascular permeability is an early event characteristic of tissue ischemia and angiogenesis. Although VEGF family members are potent promoters of endothelial permeability the role of placental growth factor (PlGF) is hotly debated. Here we investigated PlGF isoforms 1 and 2 and present in vitro and in vivo evidence that PlGF-1, but not PlGF-2, can inhibit VEGF-induced permeability but only during a critical window post-VEGF exposure. PlGF-1 promotes VE-cadherin expression via the trans-activating Sp1 and Sp3 interaction with the VE-cadherin promoter and subsequently stabilizes transendothelial junctions, but only after activation of endothelial cells by VEGF. PlGF-1 regulates vascular permeability associated with the rapid localization of VE-cadherin to the plasma membrane and dephosphorylation of tyrosine residues that precedes changes observed in claudin 5 tyrosine phosphorylation and membrane localization. The critical window during which PlGF-1 exerts its effect on VEGF-induced permeability highlights the importance of the translational significance of this work in that PLGF-1 likely serves as an endogenous anti-permeability factor whose effectiveness is limited to a precise time point following vascular injury. Clinical approaches that would pattern nature's approach would thus limit treatments to precise intervals following injury and bring attention to use of agents only during therapeutic windows

    Heme Oxygenase-1 Accelerates Cutaneous Wound Healing in Mice

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    Heme oxygenase-1 (HO-1), a cytoprotective, pro-angiogenic and anti-inflammatory enzyme, is strongly induced in injured tissues. Our aim was to clarify its role in cutaneous wound healing. In wild type mice, maximal expression of HO-1 in the skin was observed on the 2nd and 3rd days after wounding. Inhibition of HO-1 by tin protoporphyrin-IX resulted in retardation of wound closure. Healing was also delayed in HO-1 deficient mice, where lack of HO-1 could lead to complete suppression of reepithelialization and to formation of extensive skin lesions, accompanied by impaired neovascularization. Experiments performed in transgenic mice bearing HO-1 under control of keratin 14 promoter showed that increased level of HO-1 in keratinocytes is enough to improve the neovascularization and hasten the closure of wounds. Importantly, induction of HO-1 in wounded skin was relatively weak and delayed in diabetic (db/db) mice, in which also angiogenesis and wound closure were impaired. In such animals local delivery of HO-1 transgene using adenoviral vectors accelerated the wound healing and increased the vascularization. In summary, induction of HO-1 is necessary for efficient wound closure and neovascularization. Impaired wound healing in diabetic mice may be associated with delayed HO-1 upregulation and can be improved by HO-1 gene transfer
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