359 research outputs found

    On the Role of Body Size in a Tri-Trophic Metapopulation Model

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    A particular tri-trophic (resource, prey, predator) metapopulation model with dispersal of preys and predators is considered in this paper. The analysis is carried out numerically, by finding the bifurcations of the equilibria and of the limit cycles with respect to prey and predator body sizes. Two routes to chaos are identified. One is characterized by an intriguing cascade of flip and tangent bifurcations of limit cycles, while the other corresponds to the crisis of a strange attractor. The results are summarized by partitioning the space of body sizes in eight subregions, each one of which is associated to a different asymptotic behavior of the system. Emphasis is put on the possibility of having different modes of coexistence (stationary, cyclic, and chaotic) and/or extinction of the predator population

    Non-linear Isolator for Vibration and Force Transmission Control of Unbalanced Rotating Machines

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    Purpose: The objective of this paper is to investigate with simulations how non-linear spring and non-linear damper components of isolators can be employed to effectively reduce both the oscillations and the force transmitted to ground in the whole spinning range of unbalanced rotating machines. Methods: The principal goal of this paper is twofold. First, to present a concise and consistent formulation based on the harmonic balance approach for the vibration response of spinning machines mounted on linear/non-linear, softening/hardening, un-tensioned/pre-tensioned springs and linear/non-linear dampers. Second, to provide a comprehensive overview of the vibration and force transmission control with non-linear isolators specifically tailored to unbalanced machines. Results: The study has shown that, the best vibration isolation is provided by a pre-tensioned linear and cubic softening spring combined with a linear and negative quadratic damper. The pre-tensioned spring should be designed in such a way as it holds the weight of the machine and thus produces on the vibrating machine a symmetric elastic restoring force proportional to the linear and cubic powers of the displacement. The cubic softening stiffness should then be tuned to minimise the frequency, and thus the amplitude, of the resonant response of the fundamental mode of the machine and elastic suspension system, while preserving stability and a desired static deflection. In parallel, to reduce the force transmission to ground above the fundamental resonance frequency, the negative quadratic damping effect should be tailored to maximize the energy absorption at higher frequencies. Conclusion: The study has shown that non-linear spring and non-linear damper components can be effectively employed to control the vibration and force transmission in the whole spinning range of the machine. In particular, a pre-tensioned softening cubic non-linear spring can be used to mitigate the vibration and force transmission at low frequencies, close to the fundamental natural frequencies of the elastically suspended machine. Also, a negative quadratic non-linear damper can be used to tailor the energy dissipation of the isolator in such a way as to have high damping at low frequencies and low damping at higher frequencies, which enhances the vibration and force transmission control at low frequencies and, rather importantly, mitigates the force transmission at higher frequencies

    Sexual Health Dysfunction After Radiotherapy for Gynecological Cancer: Role of Physical Rehabilitation Including Pelvic Floor Muscle Training

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    Introduction: The present study aims to describe: 1. How the side effects of radiotherapy (RT) could impact sexual health in women; 2. The effectiveness of physical rehabilitation including pelvic floor muscle training (PFMT) in the management of sexual dysfunction after RT. Materials and Methods: Search keys on PubMed, Web of Science, Scopus, PEDro, and Cochrane were used to identify studies on women treated with radical or adjuvant RT and/or brachytherapy for gynecological cancers with an emphasis on vulvo-vaginal toxicities and PFMT studies on sexual dysfunction for this group of women. Results: Regarding the first key question, we analyzed 19 studies including a total of 2,739 women who reported vaginal dryness, stenosis, and pain as the most common side effects. Reports of dosimetric risk factors and dose-effect data for vaginal and vulvar post-RT toxicities are scant. Only five studies, including three randomized controlled trials (RCTs), were found to report the effect of PFMT alone or in combination with other treatments. The results showed some evidence for the effect of training modalities including PFMT, but to date, there is insufficient evidence from high-quality studies to draw any conclusion of a possible effect. Conclusions: Gynecological toxicities after RT are common, and their management is challenging. The few data available for a rehabilitative approach on post-actinic vulvo-vaginal side effects are encouraging. Large and well-designed RCTs with the long-term follow-up that investigate the effect of PFMT on vulvo-vaginal tissues and pelvic floor muscle function are needed to provide further guidance for clinical management

    Messy entanglements: research assemblages in heart transplantation discourses and practices

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    The paper engages with a variety of data around a supposedly single biomedical event, that of heart transplantation. In conventional discourse, organ transplantation constitutes an unproblematised form of spare part surgery in which failing biological components are replaced by more efficient and enduring ones, but once that simple picture is complicated by employing a radically interdisciplinary approach, any biomedical certainty is profoundly disrupted. Our aim, as a cross-sectorial partnership, has been to explore the complexities of heart transplantation by explicitly entangling research from the arts, biosciences and humanities without privileging any one discourse. It has been no easy enterprise yet it has been highly productive of new insights. We draw on our own ongoing funded research with both heart donor families and recipients to explore our different perceptions of what constitutes data and to demonstrate how the dynamic entangling of multiple data produces a constitutive assemblage of elements in which no one can claim priority. Our claim is that the use of such research assemblages and the collaborations that we bring to our project breaks through disciplinary silos to enable a fuller comprehension of the significance and experience of heart transplantation in both theory and practice

    A new approach for the treatment of CLL using chlorambucil/hydroxychloroquine-loaded anti-CD20 nanoparticles

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    Current approaches for the treatment of chronic lymphocytic leukemia (CLL) have greatly improved the prognosis for survival, but some patients remain refractive to these therapeutic regimens. Hence, in addition to reducing the long-term sideeffects of therapeutics for all leukemia patients, there is an urgent need for novel therapeutic strategies for difficult-to-treat leukemia cases. Due to the cytotoxicity of drugs, the major challenge currently is to deliver the therapeutic agents to neoplastic cells while preserving the viability of non-malignant cells. In this study, we propose a therapeutic approach in which high doses of hydroxychloroquine and chlorambucil were loaded into biodegradable polymeric nanoparticles coated with an anti-CD20 antibody.We first demonstrated the ability of the nanoparticles to target and internalize in tumor B-cells. Moreover, these nanoparticles could kill not only p53-mutated/deleted leukemia cells expressing a low amount of CD20, but also circulating primary cells isolated from chronic lymphocytic leukemia patients. The safety of these nanoparticles was also demonstrated in healthy mice, and their therapeutic effects were shown in a new model of aggressive leukemia. These results showed that anti-CD20 nanoparticles containing hydroxychloroquine and chlorambucil can be effective in controlling aggressive leukemia and provided a rationale for adopting this approach for the treatment of other B-cell disorders. [Figure not available: see fulltext.

    SF3B1-mutated chronic lymphocytic leukemia shows evidence of NOTCH1 pathway activation including CD20 downregulation

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    Chronic lymphocytic leukemia (CLL) is characterized by a low CD20 expression, in part explained by an epigenetic-driven downregulation triggered by mutations of the NOTCH1 gene. In the present study, by taking advantage of a wide and well-characterized CLL cohort (n=537), we demonstrate that CD20 expression is downregulated in SF3B1-mutated CLL in an extent similar to NOTCH1-mutated CLL. In fact, SF3B1-mutated CLL cells show common features with NOTCH1-mutated CLL cells, including a gene expression profile enriched of NOTCH1-related gene sets and elevated expression of the active intracytoplasmic NOTCH1. Activation of the NOTCH1 signaling and down-regulation of surface CD20 in SF3B1-mutated CLL cells correlate with over-expression of an alternatively spliced form of DVL2, a component of the Wnt pathway and negative regulator of the NOTCH1 pathway. These findings are confirmed by separately analyzing the CD20-dim and CD20-bright cell fractions from SF3B1-mutated cases as well as by DVL2 knock-out experiments in CLL-like cell models. Altogether, the clinical and biological features that characterize NOTCH1-mutated CLL may also be recapitulated in SF3B1-mutated CLL, contributing to explain the poor prognosis of this CLL subset and providing the rationale for expanding novel agents-based therapies to SF3B1-mutated CLL

    Ab initio simulation of photoemission spectroscopy in solids: Plane-wave pseudopotential approach, with applications to normal-emission spectra of Cu(001) and Cu(111)

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    We introduce a new method for simulating photoemission spectra from bulk crystals in the ultra-violet energy range, within a three-step model. Our method explicitly accounts for transmission and matrix-element effects, as calculated from state-of-the-art plane-wave pseudopotential techniques within density-functional theory. Transmission effects, in particular, are included by extending to the present problem a technique previously employed with success to deal with ballistic conductance in metal nanowires. The spectra calculated for normal emission in Cu(001) and Cu(111) are in fair agreement with previous theoretical results and with experiments, including a newly determined spectrum. The residual discrepancies between our results and the latter are mainly due to the well-known deficiencies of density-functional theory in accounting for correlation effects in quasi-particle spectra. A significant improvement is obtained by the LDA+U method. Further improvements are obtained by including surface-optics corrections, as described by Snell's law and Fresnel's equations.Comment: 25 pages, 7 figures, accepted in PR

    Viable tax constitutions

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    Taxation is only sustainable if the general public complies with it. This observation is uncontroversial with tax practitioners but has been ignored by the public finance tradition, which has interpreted tax constitutions as binding contracts by which the power to tax is irretrievably conferred by individuals to government, which can then levy any tax it chooses. However, in the absence of an outside party enforcing contracts between members of a group, no arrangement within groups can be considered to be a binding contract, and therefore the power of tax must be sanctioned by individuals on an ongoing basis. In this paper we offer, for the first time, a theoretical analysis of this fundamental compliance problem associated with taxation, obtaining predictions that in some cases point to a re-interptretation of the theoretical constructions of the public finance tradition while in others call them into question

    La completezza della documentazione sanitaria: ruolo dei Link Professional nel miglioramento continuo

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    INTRODUZIONE \u2013 premesse e scopo dello studio: La completezza della Cartella Clinica (CC) \ue8 un indicatore della qualit\ue0 delle cure erogate, per questo la valutazione regolare del contenuto rientra nelle attivit\ue0 di miglioramento continuo. Scopo di questo studio \ue8 valutare se il coinvolgimento e la formazione specifica di professionisti gi\ue0 impegnati nell\u2019attivit\ue0 assistenziale e clinica abbia un effetto sulla completezza della CC introdotta presso le due Strutture Operative Complesse (Medicina Fisica e Unit\ue0 Spinale, Medicina Fisica e Unit\ue0 delle Gravi Cerebro-lesioni acquisite) del Dipartimento Medicina Fisica e Riabilitazione (IMFR) di Udine. MATERIALI E METODI: Nel dicembre 2017 \ue8 stata adottata dall\u2019IMFR una nuova CC integrata multidisciplinare e ne \ue8 stato valutato l\u2019impatto in termini di completezza a gennaio 2018 (T0). Contestualmente sono stati formati sulla corretta compilazione della CC 17 link professional che, fungendo da raccordo tra i colleghi operatori e direzione ospedaliera, nelle settimane successive hanno promosso incontri periodici di formazione e approfondimento sul tema coinvolgendo tutto il personale sanitario. La completezza della CC \ue8 stata rivalutata a maggio 2018 (T1), a valle degli incontri formativi. Le misurazioni sono state effettuate mediante valutazione da parte dei link professional su 38 CC (20 a T0 ed 18 a T1) di pazienti in ricovero ordinario, utilizzando la medesima griglia composta da 10 sezioni, articolate in 59 voci. Per valutare l\u2019eventuale miglioramento \ue8 stata calcolata la completezza complessiva e la differenza tra T0 e T1 (\uf044T1-T0) in termini percentuali ed \ue8 stata effettuata una verifica del test d\u2019ipotesi con \uf0632. RISULTATI: La completezza complessiva della CC delle due strutture \ue8 aumentata significativamente (p<0,01), passando dal 62% (T0) all\u201980% (T1). A T1 \ue8 stata raggiunta, con un miglioramento significativo (p<0,01), una completezza pari al 100% nella sezione consensi (\uf044=29%), al 98% nella valutazione riabilitativa (\uf044=20%), al 92% nella lettera di dimissione (\uf044=29%), all\u201985% nella valutazione infermieristica (\uf044=13%), all\u201982% nel progetto riabilitativo individuale (\uf044=24%), al 74% nel piano integrato di cura (\uf044=15%) e al 77% nella grafica e scheda terapia (\uf044=34%). Un miglioramento, anche se non significativo, \ue8 stato registrato nelle rimanenti sezioni: valutazione medica (completezza: 82%, \uf044=6%), diario integrato (65%, \uf044=17%) e varie (64%, \uf044=8%). CONCLUSIONI: Il modello adottato si \ue8 dimostrato efficace nel supportare il processo di miglioramento della completezza della cartella clinica

    Dimensionality of genomic information and performance of the Algorithm for Proven and Young for different livestock species

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    International audienceAbstractBackgroundA genomic relationship matrix (GRM) can be inverted efficiently with the Algorithm for Proven and Young (APY) through recursion on a small number of core animals. The number of core animals is theoretically linked to effective population size (Ne). In a simulation study, the optimal number of core animals was equal to the number of largest eigenvalues of GRM that explained 98% of its variation. The purpose of this study was to find the optimal number of core animals and estimate Ne for different species.MethodsDatasets included phenotypes, pedigrees, and genotypes for populations of Holstein, Jersey, and Angus cattle, pigs, and broiler chickens. The number of genotyped animals varied from 15,000 for broiler chickens to 77,000 for Holsteins, and the number of single-nucleotide polymorphisms used for genomic prediction varied from 37,000 to 61,000. Eigenvalue decomposition of the GRM for each population determined numbers of largest eigenvalues corresponding to 90, 95, 98, and 99% of variation.ResultsThe number of eigenvalues corresponding to 90% (98%) of variation was 4527 (14,026) for Holstein, 3325 (11,500) for Jersey, 3654 (10,605) for Angus, 1239 (4103) for pig, and 1655 (4171) for broiler chicken. Each trait in each species was analyzed using the APY inverse of the GRM with randomly selected core animals, and their number was equal to the number of largest eigenvalues. Realized accuracies peaked with the number of core animals corresponding to 98% of variation for Holstein and Jersey and closer to 99% for other breed/species. Ne was estimated based on comparisons of eigenvalue decomposition in a simulation study. Assuming a genome length of 30 Morgan, Ne was equal to 149 for Holsteins, 101 for Jerseys, 113 for Angus, 32 for pigs, and 44 for broilers.ConclusionsEigenvalue profiles of GRM for common species are similar to those in simulation studies although they are affected by number of genotyped animals and genotyping quality. For all investigated species, the APY required less than 15,000 core animals. Realized accuracies were equal or greater with the APY inverse than with regular inversion. Eigenvalue analysis of GRM can provide a realistic estimate of Ne
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