5,889 research outputs found

    Distance and reddening of the Local Group dwarf irregular galaxy NGC 6822

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    On the basis of a new photometric analysis of the Local Group dwarf irregular galaxy NCG 6822 based on observations obtained with the Advanced Camera for Surveys onboard the Hubble Space Telescope, we have obtained a new estimate of the extinction of two fields located in the southeast region of the galaxy. Because of significant differences in the distance estimates to NGC 6822 available in literature, we decided to provide an independent determination of the distance to this galaxy based on an updated and self-consistent theoretical calibration of the tip of the red giant branch brightness. As a result we newly determined the distance to NGC 6822 to be equal to (mM)0=23.54±0.05{\rm(m-M)}_0=23.54\pm 0.05, and compared our measurement with the most recent determinations of this distance.Comment: 5 pages, 5 figures, Astronomy & Astrophysics (Research Note), in press (proof correction included

    Co-production in healthcare services: What we know, how we can evaluate it

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    Background In times of increasing population aging, higher incidence of chronic diseases and higher expectations regarding public service provision, healthcare services are under increasing strain to cut costs while keeping quality. In this context, debates on the importance of promoting systems of co-produced health between stakeholders have gained considerable traction both in the literature and in policy debates of the public sector (Dunston et al., 2009, Voorberg et al. 2015; European Commission 2010). Co-production occurs \u201cwhen public service organizations partner with external entities, including other public organizations, third sector, or service user, to jointly produce services that they previously produced on their own\u201d (Thomas, 2013, p. 788). In this perspective, co-production is not only a patient involvement tool, but mainly a managerial tool, where partner in the production process could influence the methods used to organise and manage the service delivery (Sorrentino et al., 2015; Brandsen and Honingh, 2015; Gilardi et al., 2016). Despite this widespread acceptance, minimal consensus exists on the mechanisms for evaluating the actual impacts of the co-production in healthcare sector. More specifically, little has been produced on how the results of these changing structures, practices and goals in healthcare management and provision can be monitored and evaluated (Hardyman et al., 2015; Gilardi et al., 2016; Palumbo, 2016). Objectives The study aims at filling this gap by developing a conceptual framework for assessing co-production in healthcare. Specifically, drawing on existing literature on co-production in healthcare, we develop an original analytical evaluation framework with respect to: i) the multidimensional perspectives to be taken into consideration; ii) the dimensions to be analysed; iii) the methods that allow implementing our framework in practice. Methodolody First of all, a quantitative bibliometric analysis, using Bibliometrix software (Aria and Cuccurullo, 2017), is carried out. The reference database chosen is WoS and the inclusion criterion is \u201cco-production AND heath* OR coproduction AND health*\u201d in topic. Moreover, the search is refined by language, i.e. English, and type of publication, i.e. journal academic article. No time limitation is selected. After deleting non-inherent papers, our final sample was made up of 213 papers. As second stage, a qualitative content analysis based on PRISMA protocol is developed, focusing on those papers targeting evaluation issues. Finally, a preliminary co-production evaluation model proposal is proposed and discussed. Main results The study shows an increasing attention on the co-production topic, as highlighted by an annual percentage growth rate of about 26% and the big increase in the last 5 years in number of publications. The countries with a highest number of publications and collaborations are UK (mainly England), Netherlands, Australia and USA. As expected, the most repeated keyword is co-production, however, it is interesting to underline the presence of \u201cmental health\u201d and \u201cpublic health\u201d, that can be assumed as the main topic of studies analyzed. Nonetheless, only few studies focus on the evaluation of outcomes. Among them, the content analysis has revealed a predominantly mono-dimensional and mono-stakeholder approach. Specifically, clinical, economic or psychological-social - mainly in terms of patient satisfaction \u2013 impacts (i.e. Lwembe et al., 2016; Harvey et al., 2017) are assessed. The analysis reveals that one of the main challenges of assessing co-production lies in its multi-dimensional nature; thus a multiple perspectives framework has to be adopted. To contribute filling this gap, we developed a preliminary multidimensional (i.e. performance indicators) and multi-stakeholder (i.e. different actors involved) evaluation model (Figure 1). Specifically, the framework takes into account the three main outcome domains \u2013 i) economic, ii) managerial/organisational and iii) clinical \u2013 and three main stakeholders involved \u2013 i) hospital, ii) healthcare professionals, iii) patients and their families. The economic and efficiency measures concerning direct and indirect cost for hospital and patients/family, should be integrated with clinical and managerial measures for each stakeholder: 1. Hospital: administrative efficiency, activating capacity, inclusiveness of decision making, stability/flexibility of rules, conflict resolution and collaboration climate, frequency of interaction. 2 Patient (and caregiver or family): objective (i.e. compliance) and subjective (i.e. quality of life, quality of care perception, patient satisfaction) indicators. 3. Healthcare professional and staff: objective (e.g. turnover rate, absences, injuries and work-related ill health) and subjective (e.g. burnout, satisfaction, healthcare professional engagement, occupational health, risk perception) indicators

    HJ Inequalities Involving Lie Brackets and Feedback Stabilizability with Cost Regulation

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    With reference to an optimal control problem where the state has to approach asymptotically a closed target while paying a non-negative integral cost, we propose a generalization of the classical dissipative relation that defines a Control Lyapunov Function to a weaker differential inequality. The latter involves both the cost and the iterated Lie brackets of the vector fields in the dynamics up to a certain degree k = 1, and we call any of its (suitably defined) solutions a degree -k Minimum Restraint Function. We prove that the existence of a degree -k Minimum Restraint Function allows us to build a Lie-bracket-based feedback which sample stabilizes the system to the target while regulating (i.e., uniformly bounding) the cost

    A state-of-the-art analysis of the dwarf irregular galaxy NGC 6822

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    We present a detailed photometric study of the dwarf irregular galaxy NGC 6822 aimed at investigating the properties of its stellar populations and, in particular, the presence of stellar radial gradients. Our goal is to analyse the stellar populations in six fields, which cover the whole bar of this dwarf galaxy. We derived the quantitative star formation history (SFH) of the six fields using the IAC method, involving IAC-pop/MinnIAC codes. The solutions we derived show an enhanced star formation rate (SFR) in Fields 1 and 3 during the past 500 Myr. The SFRs of the other fields are almost extinguished at very recent epochs and. We study the radial gradients of the SFR and consider the total mass converted into stars in two time intervals (between 0 and 0.5 Gyr ago and between 0.5 and 13.5 Gyr ago). We find that the scale lengths of the young and intermediate-to-old populations are perfectly compatible, with the exception of the young populations in Fields 1 and 3. The recent SF in these two fields is greater than in the other ones. This might be an indication that in these two fields we are sampling incipient spiral arms. Further evidence and new observations are required to prove this hypothesis. In addition, we derived the age-metallicity relations. As expected, the metallicity increases with time for all of the fields. We do not observe any radial gradient in the metallicity.Comment: 9 pages, 11 figures, Accepted to A&

    Sexually Transmitted Disease and Male Infertility: A Systematic Review

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    Context Theoretically, sexually transmitted diseases (STDs) have the potential to disrupt male fertility; however, the topic remains controversial. Objective To describe the possible association between STDs and male infertility and to explore possible pathophysiologic mechanisms. Evidence acquisition We performed a systematic literature review in accordance with the PRISMA guidelines. PubMed, Embase, and the Cochrane Library were searched for articles published before January 1, 2016, using the MeSH terms for a variety of STDs and infertility. The search was restricted to human studies performed in men and published in English. Studies were included if they contained original data on a possible association or a cause-and-effect relationship between STD and male infertility. Studies were considered only if they included an appropriate control group and/or comprehensive laboratory data. Due to heterogeneity in the literature, a qualitative analysis was performed. Evidence synthesis Relevant studies on Chlamydia trachomatis, genital mycoplasmas, Neisseria gonorrhoeae, Trichomonas vaginalis, and viral infections were identified. For all pathogens, the studies were contradictory and generally of limited quality. In studies confirming an association, there was a tendency for authors to perform multiple analyses without appropriate corrections and to subsequently focus solely on outcomes that seemed to suggest a positive association; however, the body of literature that does not confirm an association between STDs and male infertility is also of inadequate quality. The data regarding possible pathophysiologic mechanisms are inconclusive. Conclusions There may be an association between STDs and male infertility of unknown genesis and possibly with different pathogenic mechanisms for different pathogens. Alternatively, some STDs may cause male infertility, whereas others may not; however, there is hardly a strong correlation. High-quality studies of the subject are needed. Patient summary Sexually transmitted diseases may cause male infertility through unknown mechanisms; however, from the available research, we cannot be sure that there is an association, and more studies are needed

    Truthful Matching with Online Items and Offline Agents

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    We study truthful mechanisms for welfare maximization in online bipartite matching. In our (multiparameter) setting, every buyer is associated with a (possibly private) desired set of items, and has a private value for being assigned an item in her desired set. Unlike most online matching settings, where agents arrive online, in our setting the items arrive online in an adversarial order while the buyers are present for the entire duration of the process. This poses a significant challenge to the design of truthful mechanisms, due to the ability of buyers to strategize over future rounds. We provide an almost full picture of the competitive ratios in different scenarios, including myopic vs. non-myopic agents, tardy vs. prompt payments, and private vs. public desired sets. Among other results, we identify the frontier up to which the celebrated e/(e − 1) competitive ratio for the vertex-weighted online matching of Karp, Vazirani and Vazirani extends to truthful agents and online items.</p

    Técnicas de levantamento e monitoração de populações de carnívoros

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    Diferentes técnicas vêm sendo utilizadas em levantamentos de carnívoros, e o principal fator que influencia as estimativas é a detectabilidade. Raramente todos os animais presentes em uma dada área são detectados num levantamento, e a maioria das estimativas são baseadas em contagens incompletas. Por outro lado, nem sempre se faz necessário a obtenção de estimativas de abundãncia absoluta ou de densidade absoluta, e um índice de abundância pode ser o suficiente para, por exemplo, avaliar as tendências da população. Índices de abundância precisam ter uma forte correlação com a abundância absoluta ou com a densidade, para que sejam úteis. Índices podem ser obtidos de contagens incompletas, em relação ao esforço empregado, usando sinais da presença de animais, fotografia remota e outras técnicas. Métodos para estimar a densidade ou abundância absoluta podem ser divididos em diretas e indiretas.bitstream/CPAP/55978/1/DOC73.pdfFormato Eletrônic

    Dystonia: sparse synapses for D2 receptors in striatum of a DYT1 knock-out mouse model

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    Dystonia pathophysiology has been partly linked to downregulation and dysfunction of dopamine D2 receptors in striatum. We aimed to investigate the possible morpho-structural correlates of D2 receptor downregulation in the striatum of a DYT1 Tor1a mouse model. Adult control Tor1a+/+ and mutant Tor1a+/− mice were used. The brains were perfused and free-floating sections of basal ganglia were incubated with polyclonal anti-D2 antibody, followed by secondary immune-fluorescent antibody. Confocal microscopy was used to detect immune-fluorescent signals. The same primary antibody was used to evaluate D2 receptor expression by western blot. The D2 receptor immune-fluorescence appeared circumscribed in small disks (~0.3–0.5 μm diameter), likely representing D2 synapse aggregates, densely distributed in the striatum of Tor1a+/+ mice. In the Tor1a+/− mice the D2 aggregates were significantly smaller (μm2 2.4 ± SE 0.16, compared to μm2 6.73 ± SE 3.41 in Tor1a+/+) and sparse, with ~30% less number per microscopic field, value correspondent to the amount of reduced D2 expression in western blotting analysis. In DYT1 mutant mice the sparse and small D2 synapses in the striatum may be insufficient to “gate” the amount of presynaptic dopamine release diffusing in peri-synaptic space, and this consequently may result in a timing and spatially larger nonselective sphere of influence of dopamine action
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