1,031 research outputs found

    Optimal Control and Sensitivity Analysis of a Fractional Order TB Model

    Full text link
    A Caputo fractional-order mathematical model for the transmission dynamics of tuberculosis (TB) was recently proposed in [Math. Model. Nat. Phenom. 13 (2018), no. 1, Art. 9]. Here, a sensitivity analysis of that model is done, showing the importance of accuracy of parameter values. A fractional optimal control (FOC) problem is then formulated and solved, with the rate of treatment as the control variable. Finally, a cost-effectiveness analysis is performed to assess the cost and the effectiveness of the control measures during the intervention, showing in which conditions FOC is useful with respect to classical (integer-order) optimal control.Comment: This is a preprint of a paper whose final and definite form is with 'Statistics Opt. Inform. Comput.', Vol. 7, No 2 (2019). See [http://www.IAPress.org]. Submitted 09/Sept/2018; Revised 10/Dec/2018; Accepted 11/Dec/2018. arXiv admin note: text overlap with arXiv:1801.09634, arXiv:1810.0690

    Optimal control of a fractional order epidemic model with application to human respiratory syncytial virus infection

    Get PDF
    A human respiratory syncytial virus surveillance system was implemented in Florida in 1999, to support clinical decision-making for prophylaxis of premature newborns. Recently, a local periodic SEIRS mathematical model was proposed in [Stat. Optim. Inf. Comput. 6 (2018), no.1, 139--149] to describe real data collected by Florida's system. In contrast, here we propose a non-local fractional (non-integer) order model. A fractional optimal control problem is then formulated and solved, having treatment as the control. Finally, a cost-effectiveness analysis is carried out to evaluate the cost and the effectiveness of proposed control measures during the intervention period, showing the superiority of obtained results with respect to previous ones.Comment: This is a preprint of a paper whose final and definite form is with 'Chaos, Solitons & Fractals', available from [http://www.elsevier.com/locate/issn/09600779]. Submitted 23-July-2018; Revised 14-Oct-2018; Accepted 15-Oct-2018. arXiv admin note: substantial text overlap with arXiv:1801.0963

    Fast Split-Radix and Radix-4 Discrete Cosine Transform Algorithms

    Get PDF
    The Discrete Fourier Transform (DFT) has a plethora of applications in applied mathematics and electrical engineering. Discrete Cosine Transform (DCT) is a real-arithmetic analogue of DFT. DCTs with orthogonal trigonometric transforms have been especially popular in recent decades due to their applications in digital video technology and high efficiency video coding. One can say that DCT is the key transform in image processing, signal processing, finger print enhancement, quick response code (QR code), multi-mode interface, etc. In this talk, we first introduce sparse and scaled orthogonal factorization for the DCT and inverse DCT. Afterwards, we present fast split-radix and radix-4 DCT and inverse DCT algorithms. We show that the proposed algorithms attain the lowest theoretical multiplication complexity and arithmetic complexity for 8-point DCT II/III matrices. We perform execution time of the proposed algorithms while verifying the connection to the order of the arithmetic complexity. Finally, the language of signal flow graph representation of digital structures is used to describe potential for real-world circuit implementation

    Contact-dependent Stimulation and Inhibition of Dendritic Cells by Natural Killer Cells

    Get PDF
    Natural killer (NK) cells and dendritic cells (DCs) are two distinct cell types of innate immunity. It is known that the in vitro interaction of human NK cells with autologous DCs results in DC lysis. Here we show that contact-dependent interactions between activated human NK cells and immature DCs (iDCs) provides a “control switch” for the immune system. At low NK/DC ratios, this interaction dramatically amplifies DC responses, whereas at high ratios it completely turns off their responses. Specifically, culture of activated human NK cells with iDCs, at low NK/DC ratios (1:5), led to exponential increases in DC cytokine production, which were completely dependent on cell-to-cell contact. DC maturation was also driven by cognate interactions with NK cells and maturation was dependent on endogenously produced TNF-α in the culture. At slightly higher NK/DC ratios (5:1), inhibition of DC functions was the dominant feature due to potent killing by the autologous NK cells. Resting NK cells also stimulated autologous DC maturation in a TNF-α/contact-dependent manner, however, increasing the NK/DC ratio only led to an enhancement of this effect

    Virtual reality interventions designed to support parents during and throughout the first year after birth:A scoping review

    Get PDF
    ObjectiveVirtual reality (VR) has become increasingly popular in clinical and health settings where it has been used for a wide range of purposes. A recent scoping review explored VR applications to assist pregnant women and found that VR was a useful method to be used for a range of different purposes in both pregnancy and labour. However, no such review exists for the period after birth.MethodWe aimed to search for studies that used VR to support parents during birth and in the first year postpartum (Population) in different settings (Context), and finally provided data on the characteristics, reported effectiveness and experience of VR interventions (Concept). Two hundred and fifty-one studies were identified, of which ten were eligible. Two authors independently extracted data including study design, participants and results.ResultsFindings indicate that VR has been used effectively in this context to alleviate depression anxiety, and multiple domains of pain and to improve childbirth satisfaction. The majority of the studies explored the use of VR technology on outcomes such as pain and anxiety during labour and birth. The studies included used a broad range of VR hardware and software. All of the studies reported positive experiences of using VR.ConclusionsAcross these studies, VR was found to be effective in terms of both physiological and psychological outcomes. There are many unexplored maternal and infant focused applications of VR which warrant further investigation as emerging evidence indicates this is becoming an increasingly accessible method to improve maternal and infant health outcomes from pregnancy through to parenthood

    Microsatellite transferability from Brachiaria ruziziensis to B. humidicola and genetic similarity among evaluated genotypes.

    Get PDF
    Species from the genus Brachiaria play an important role in tropical pastures. Brachiaria ruziziensis presents di and tetraploid cytotypes and B. humidicola presents from tetra to heptaploid cytotypes. Although they belong to the same genus, these species belong to different agamic complexes

    Low-dietary fiber intake as a risk factor for recurrent abdominal pain in children

    Get PDF
    Objective: To evaluate dietary fiber intake in children with recurrent abdominal pain.Design: Cross-sectional study with control group.Setting: Outpatients of the Pediatric Gastroenterology public health clinic of the Darcy Vargas Children's Hospital, Brazil.Subjects: Forty-one patients with recurrent abdominal pain were evaluated and 41 children, as a control group.Interventions: Macronutrients and fiber intake evaluation by the Daily Food Intake method. Two tables of fiber composition in foods were used.Results: According to the Brazilian table the mean intake of fiber ( g/day) by the children of the recurrent abdominal pain groups with chronic constipation or not, and the control group was, respectively, 18.2, 16.6 and 23.7 for total fiber ( P 0.001), 7.5, 6.9 and 9.5 for soluble fiber ( P 0.001) and 10.7, 9.7 and 14.1 for insoluble fiber ( P 0.002). According to the AOAC table, the recurrent abdominal pain group with chronic constipation or not ( 10.6 and 9.9 g/day) also had lower intake of total fiber than the control group ( 13.4 g/day) ( P 0.008). the intake of fiber was lower than the minimum recommended value ( age+5g) and statistically associated ( P 0.021) with the recurrent abdominal pain group ( 78%) in comparison with the control one ( 51.2%). the odds ratio was 3.39 ( 95% CI, 1.18 - 9.95).Conclusion: fiber intake below the minimum recommended value is a risk factor for recurrent abdominal pain in children.Universidade Federal de SĂŁo Paulo, Dept Pediat, Paulista Sch Med, BR-04023062 SĂŁo Paulo, BrazilDarcy Vargas Childrens Hosp, SĂŁo Paulo, BrazilUniversidade Federal de SĂŁo Paulo, Dept Pediat, Paulista Sch Med, BR-04023062 SĂŁo Paulo, BrazilWeb of Scienc

    Pills and prayers: a comparative qualitative study of community conceptualisations of pre-eclampsia and pluralistic care in Ethiopia, Haiti and Zimbabwe.

    Full text link
    BACKGROUND: Pre-eclampsia is a leading cause of preventable maternal and perinatal deaths globally. While health inequities remain stark, removing financial or structural barriers to care does not necessarily improve uptake of life-saving treatment. Building on existing literature elaborating the sociocultural contexts that shape behaviours around pregnancy and childbirth can identify nuanced influences relating to pre-eclampsia care. METHODS: We conducted a cross-cultural comparative study exploring lived experiences and understanding of pre-eclampsia in Ethiopia, Haiti and Zimbabwe. Our primary objective was to examine what local understandings of pre-eclampsia might be shared between these three under-resourced settings despite their considerable sociocultural differences. Between August 2018 and January 2020, we conducted 89 in-depth interviews with individuals and 17 focus group discussions (n = 106). We purposively sampled perinatal women, survivors of pre-eclampsia, families of deceased women, partners, older male and female decision-makers, traditional birth attendants, religious and traditional healers, community health workers and facility-based health professionals. Template analysis was conducted to facilitate cross-country comparison drawing on Social Learning Theory and the Health Belief Model. RESULTS: Survivors of pre-eclampsia spoke of their uncertainty regarding symptoms and diagnosis. A lack of shared language challenged coherence in interpretations of illness related to pre-eclampsia. Across settings, raised blood pressure in pregnancy was often attributed to psychosocial distress and dietary factors, and eclampsia linked to spiritual manifestations. Pluralistic care was driven by attribution of causes, social norms and expectations relating to alternative care and trust in biomedicine across all three settings. Divergence across the contexts centred around nuances in religious or traditional practices relating to maternal health and pregnancy. CONCLUSIONS: Engaging faith and traditional caregivers and the wider community offers opportunities to move towards coherent conceptualisations of pre-eclampsia, and hence greater access to potentially life-saving care

    Alterações histológicas dos rins e expressão das metalotioneínas e das proteínas de choque térmico em ratos Wistar após exposição ao fungicida tirame

    Get PDF
    The histological alterations and the expression of metallothionein (MTs) and heat shock protein (Hsp70) in the kidney of Wistar rats after thiram fungicide exposure were evaluated. Animals were distributed into three groups: standard diet group, standard diet + corn oil group and thiram group. Significant differences were found (P<0,05) in the evolution of body weight between rats in the thiram group and those in the control and corn oil groups, and no histological lesions were evident in the animals' kidneys. Differences were found among animals in the group exposed to thiram and the control and oil groups regarding histomorphometric characteristics of the renal corpuscle - except for the proportion in the area of Bowman's capsule: glomerulus area - and regarding the height of the epitelium in the distal tubules. In rats exposed to thiram, a positive moderate to strong immunoexpression was observed for MTs, in the cortical convulated tubules decreasing the cortex towards the medulla, and a strong immunoexpression for Hsp70 in the cortex and medulla areas, in the glomerulus and convulated tubules. The results suggest that thiram may have chronic toxicity in mammals affecting their growth, and that the expression of MTs and Hsp70, a probable cellular adaptive response to the oxidative stress caused by thiram, may be used as a biomarker of exposure to this chemical.info:eu-repo/semantics/publishedVersio
    • …
    corecore