Some notes on fixed points of quasi-contraction maps

AbstractIn this paper, we shall give some results about fixed points of quasi-contraction maps on cone metric spaces. These results generalize some recent results

Parallel Shooting Sequential Quadratic Programming for Nonlinear MPC Problems

In this paper, we propose a parallel shooting algorithm for solving nonlinear model predictive control problems using sequential quadratic programming. This algorithm is built on a two-phase approach where we first test and assess sequential convergence over many initial trajectories in parallel. However, if none converge, the algorithm starts varying the Newton step size in parallel instead. Through this parallel shooting approach, it is expected that the number of iterations to converge to an optimal solution can be decreased. Furthermore, the algorithm can be further expanded and accelerated by implementing it on GPUs. We illustrate the effectiveness of the proposed Parallel Shooting Sequential Quadratic Programming (PS-SQP) method in some benchmark examples for nonlinear model predictive control. The developed PS-SQP parallel solver converges faster on average and especially when significant nonlinear behaviour is excited in the NMPC horizon.Comment: 7 pages, 6 figures, submitted and accepted for the 7th IEEE Conference on Control Technology and Applications (CCTA) 202

Observational Constraints on the Modified Gravity Model (MOG) Proposed by Moffat: Using the Magellanic System

A simple model for the dynamics of the Magellanic Stream (MS), in the framework of modified gravity models is investigated. We assume that the galaxy is made up of baryonic matter out of context of dark matter scenario. The model we used here is named Modified Gravity (MOG) proposed by Moffat (2005). In order to examine the compatibility of the overall properties of the MS under the MOG theory, the observational radial velocity profile of the MS is compared with the numerical results using the $\chi^2$ fit method. In order to obtain the best model parameters, a maximum likelihood analysis is performed. We also compare the results of this model with the Cold Dark Matter (CDM) halo model and the other alternative gravity model that proposed by Bekenstein (2004), so called TeVeS. We show that by selecting the appropriate values for the free parameters, the MOG theory seems to be plausible to explain the dynamics of the MS as well as the CDM and the TeVeS models.Comment: 14 pages, 3 Figures, accepted in Int. J. Theor. Phy

Mono- and Cocultures of Bronchial and Alveolar Epithelial Cells Respond Differently to Proinflammatory Stimuli and Their Modulation by Salbutamol and Budesonide

© 2015 American Chemical Society. The aim of this study was to investigate the changes in transport and effectiveness of salbutamol sulfate (SAL) and budesonide (BD) following stimulation with transforming growth factor-β (TGF-β) in mono- and coculture models of bronchial and alveolar epithelium. Primary bronchial and alveolar epithelial cells, grown at air interface on filters, either as monocultures or in coculture with airway smooth muscle cells or alveolar macrophages, respectively, were stimulated with TGF-β. The biological response was modulated by depositing aerosolized SAL and BD on bronchial and alveolar models, respectively. Barrier integrity, permeability to fluorescein-Na, transport of the deposited drug, and the pharmacological response to SAL (cAMP and IL-8 levels) or BD (IL-6 and -8 levels) were measured. While stimulation with TGF-β did not have any significant effect on the transepithelial electrical resistance and permeability to fluorescein-Na in mono- and coculture models, transport of SAL and BD were affected in cultures from some of the patients (6 out of 12 for bronchial and 2 out of 4 for alveolar cells). The bronchial coculture showed a better responsiveness to SAL in terms of cAMP release than the monoculture. In contrast, the difference between alveolar mono- and cocultures to TGF-β mediated interleukin release and its modulation by BD was less pronounced. Our data point to intrinsic differences in the transport of, and responsiveness to, SAL and BD when epithelial cell cultures originate from different patients. Moreover, if the biological responses (e.g., IL-8, cAMP) involve communication between different cell types, coculture models are more relevant to measure such effects than monocultures

Gravitational anomalies signaling the breakdown of classical gravity

Recent observations for three types of astrophysical systems severely challenge the GR plus dark matter scenario, showing a phenomenology which is what modified gravity theories predict. Stellar kinematics in the outskirts of globular clusters show the appearance of MOND type dynamics on crossing the $a_{0}$ threshold. Analysis shows a ``Tully-Fisher'' relation in these systems, a scaling of dispersion velocities with the fourth root of their masses. Secondly, an anomaly has been found at the unexpected scales of wide binaries in the solar neighbourhood. Binary orbital velocities cease to fall along Keplerian expectations, and settle at a constant value, exactly on crossing the $a_{0}$ threshold. Finally, the inferred infall velocity of the bullet cluster is inconsistent with the standard cosmological scenario, where much smaller limit encounter velocities appear. This stems from the escape velocity limit present in standard gravity; the ``bullet'' should not hit the ``target'' at more than the escape velocity of the joint system, as it very clearly did. These results are consistent with extended gravity, but would require rather contrived explanations under GR, each. Thus, observations now put us in a situation where modifications to gravity at low acceleration scales cease to be a matter of choice, to now become inevitable.Comment: 10 pages, 5 figures, Astrophysics and Space Science Proceedings 38, 4

The role of melatonin on chemotherapy-induced reproductive toxicity

Abstract Objectives Reproductive malfunctions after chemotherapy still are a reason of reducing fertility and need specialized intensive care. The aim of this review was to investigate the effect of melatonin on the reproductive system under threatening with chemotherapeutic drugs. Methods To find the role of melatonin in the reproductive system during chemotherapy, a full systematic literature search was carried out based on Preferred Reporting Items for Systematic Reviews and Meta‐Analyses guidelines in the electronic databases up to 17 April 2017 using search terms in the titles and abstracts. A total of 380 articles are screened according to our inclusion and exclusion criteria. Finally, 18 articles were included in this study. Key findings It has been cleared that melatonin has bilateral effects on reproductive cells. Melatonin protects normal cells via mechanisms, including decrease in oxidative stress, apoptosis, inflammation and modulating mitochondrial function, and sexual hormones. Furthermore, melatonin with antiproliferative properties and direct effects on its receptors improves reproductive injury and function during chemotherapy. On the other hand, melatonin sensitizes the effects of chemotherapeutic drugs and enhances chemotherapy‐induced toxicity in cancerous cells through increasing apoptosis, oxidative stress and mitochondrial malfunction. Conclusions The study provides evidence of the bilateral role of melatonin in the reproductive system during chemotherapy

Protective psychosocial factors of geriatric depression in community dwelling older adults: A review article

Context: Depression is a major health problem in geriatric population and has many adverse consequences. The aim of this study was to review the existing literature on psychosocial factors that protect against depression in later life. Evidence Acquisition: A MEDLINE systematic search was done via Pubmed and Sciencedirect web pages to gather the published articles on psychosocial factors of late life depression First, the titles and abstracts reviewed and relevant articles were selected according to the inclusion criteria. Then full texts of the selected articles obtained, read, and data were extracted and categorized. Results: There were 204 articles on psychosocial factors of late life depression in community dwelling older adults and among them 29 articles included protective factors. Reading them carefully, protective factors were extracted and organized into 5 main categories: Demographic factors, psychological factors, social factors, health related factors and also spiritual factors. Conclusion: Psychosocial factors protecting older adults against depression are diverse. Identification of the modifiable ones and provision of appropriate interventions to enhance them, can be helpful in preventing geriatric depression. ©2018, Iranian Journal of Psychiatry and Behavioral Sciences

A systematic review of radiation-induced testicular toxicities following radiotherapy for prostate cancer

Background: Prostate cancer is the second most common malignancy in men in the world, and radiotherapy is used as a standard treatment modality for this cancer. Although this treatment modality effectively kills prostate cancerous cells, it unavoidably irradiates the organs/tissues that are away from the treatment site. In this regard, radiation-induced testicular toxicities following prostate radiotherapy can affect sexual function, reproduction, and quality of life in cancer survivors. This review summarizes the available data on testicular exposure to radiation during prostate radiotherapy and the consequences on testicular function. Methods: To illuminate the radiation-induced testicular toxicities following prostate radiotherapy, a systematic search was conducted based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guideline in PubMed, Web of Science, Scopus, Embase, and clinical trials electronic databases up to September 2018. According to a set of prespecified inclusion and exclusion criteria, 31 eligible articles providing data on testicular function following radiotherapy in patients with prostate cancer were included in the study. Results: According to the different radiotherapeutic techniques used for prostate cancer treatment, the total tumor dose and scattered testicular dose values were ranging from 36.25 to 78.00 Gy and 0.06 to 6.48 Gy, respectively. Luteinizing hormone and follicle-stimulating hormone levels after prostate radiotherapy were signi�cantly higher in comparison with the pretreatment levels. Around 60 of the studies showed that testosterone levels after prostate radiotherapy were signi�cantly lower than the pretreatment levels. Furthermore, erectile dysfunction (ED), as an adverse side effect resulting from prostate radiotherapy, was reported and this complication is signi�cantly correlated with lower satisfaction with sexual life. Testicular atrophy following prostate radiotherapy has also been observed and its frequency in patients with prior prostate radiotherapy is 2.5 times more than that in the patients without prior radiotherapy. Conclusion: The data revealed that the scattered dose to testicular tissues during prostate radiotherapy can lead to testicular atrophy, variation of the male sex hormones, and quality of sexual life. © 2019 Wiley Periodicals, Inc