339 research outputs found

    Twisted partial actions of Hopf algebras

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    In this work, the notion of a twisted partial Hopf action is introduced as a unified approach for twisted partial group actions, partial Hopf actions and twisted actions of Hopf algebras. The conditions on partial cocycles are established in order to construct partial crossed products, which are also related to partially cleft extensions of algebras. Examples are elaborated using algebraic groups

    C*-algebras associated with endomorphisms and polymorphisms of compact abelian groups

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    A surjective endomorphism or, more generally, a polymorphism in the sense of \cite{SV}, of a compact abelian group HH induces a transformation of L2(H)L^2(H). We study the C*-algebra generated by this operator together with the algebra of continuous functions C(H)C(H) which acts as multiplication operators on L2(H)L^2(H). Under a natural condition on the endo- or polymorphism, this algebra is simple and can be described by generators and relations. In the case of an endomorphism it is always purely infinite, while for a polymorphism in the class we consider, it is either purely infinite or has a unique trace. We prove a formula allowing to determine the KK-theory of these algebras and use it to compute the KK-groups in a number of interesting examples.Comment: 25 page

    The relations between hope and subjective well-being: A literature overview and empirical analysis

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    How we perceive the future can greatly affect how we feel in the present. Even a currently positive situation is hard to bear when we know the future will be grim. Indeed, previous research has found that more hopeful people are happier. However, both hope and subjective well-being are multidimensional concepts comprising emotion (i.e., anticipation and affect), cognition (expectation and satisfaction) and, to some degree, motivation. Since most studies include only one dimension of hope and subjective well-being, little is known about how different aspects of hope relate to different aspects of subjective well-being. This study aims to gain insight into these relationships by providing an overview of the existing empirical literature on hope and subjective well-being. Subsequently, cross-sectional data of a representative sample of the American population are used to further examine the relationship between hope and subjective well-being. Our findings from both the literature and our empirical analysis show that positive expectations are only weakly associated with all domains of subjective well-being, whereas cognitive and emotional hope are most strongly related to subjective well-being. This finding indicates that the more passive characteristics of positive expectations have less of an impact on subjective well-being than a more agentic hopeful disposition

    Hope Mediates the Relation between Income and Subjective Well-Being

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    In this study, we examine whether the positive effect of income gains on subjective well-being (SWB) can in part be explained by the improved future prospects that are generated by a more solid financial situation. Using three-wave panel data from the US, we inspect the relation between changes in income, hope and SWB using a fixed-effects model. Results show that hope indeed partially mediates the relation between income and SWB, but only for monthly incomes over $1800. Positive expectations, on the other hand, mediate the relation for all income levels. From the two components of hope, agency, the belief that we can achieve our goals, seems to be the strongest mediator. We find no indications that extremely high levels of hope or expectations will harm SWB through disappointment

    Public Preferences for Introducing a COVID-19 Certificate:A Discrete Choice Experiment in the Netherlands

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    Objective: Here we investigate public preferences for coronavirus disease 2019 (COVID-19) certificates in the Netherlands, and whether these preferences differ between subgroups in the population. Methods: A survey including a discrete choice experiment was administered to 1500 members of the adult population of the Netherlands. Each participant was asked to choose between hypothetical COVID-19 certificates that differed in seven attributes: the starting date, and whether the certificate allowed gathering with multiple people, shopping without appointment, visiting bars and restaurants, visiting cinemas and theatres, attending events, and practising indoor sports. Latent class models (LCMs) were used to determine the attribute relative importance and predicted acceptance rate of hypothetical certificates. Results: Three classes of preference patterns were identified in the LCM. One class a priori opposed a certificate (only two attributes influencing preferences), another class was relatively neutral and included all attributes in their decision making, and the final class was positive towards a certificate. Respondents aged > 65 years and those who plan to get vaccinated were more likely to belong to the latter two classes. Being allowed to shop without appointment and to visit bars and restaurants was most important to all respondents, increasing predicted acceptance rate by 12 percentage points. Conclusions: Preferences for introduction of a COVID-19 certificate are mixed. A certificate that allows for shopping without appointment and visiting bars and restaurants is likely to increase acceptance. The support of younger citizens and those who plan to get vaccinated seems most sensitive to the specific freedoms granted by a COVID-19 certificate

    Whether, when and how chronic inflammation increases the risk of developing late-onset Alzheimer's disease

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    Neuropathological studies have revealed the presence of a broad variety of inflammation-related proteins (complement factors, acute-phase proteins, pro-inflammatory cytokines) in Alzheimer's disease (AD) brains. These constituents of innate immunity are involved in several crucial pathogenic events of the underlying pathological cascade in AD, and recent studies have shown that innate immunity is involved in the etiology of late-onset AD. Genome-wide association studies have demonstrated gene loci that are linked to the complement system. Neuropathological and experimental studies indicate that fibrillar amyloid-beta (A beta) can activate the innate immunity-related CD14 and Toll-like receptor signaling pathways of glial cells for pro-inflammatory cytokine production. The production capacity of this pathway is under genetic control and off spring with a parental history of late-onset AD have a higher production capacity for pro-inflammatory cytokines. The activation of microglia by fibrillar A beta deposits in the early preclinical stages of AD can make the brain susceptible later on for a second immune challenge leading to enhanced production of pro-inflammatory cytokines. An example of a second immune challenge could be systemic inflammation in patients with preclinical AD. Prospective epidemiological studies show that elevated serum levels of acute phase reactants can be considered as a risk factor for AD. Clinical studies suggest that peripheral inflammation increases the risk of dementia, especially in patients with preexistent cognitive impairment, and accelerates further deterioration in demented patients. The view that peripheral inflammation can increase the risk of dementia in older people provides scope for preventio

    Stakeholder perspectives on payment reform in maternity care in the Netherlands:A Q-methodology study

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    Based on theoretical notions, there is consensus that alternative payment models to the common fee-for-service model have the potential to improve healthcare quality through increased collaboration and reduced under- and overuse. This is particularly relevant for maternity care in the Netherlands because perinatal mortality rates are relatively high in comparison to other Western countries. Therefore, an experiment with bundled payments for maternity care was initiated in 2017. However, the uptake of this alternative payment model remains low, as also seen in other countries, and fee-for-service models prevail. A deeper understanding of stakeholders’ perspectives on payment reform in maternity care is necessary to inform policy makers about the obstacles to implementing alternative payment models and potential ways forward. We conducted a Q-methodology study to explore perspectives of stakeholders (postpartum care managers, midwives, gynecologists, managers, health insurers) in maternity care in the Netherlands on payment reform. Participants were asked to rank a set of statements relevant to payment reform in maternity care and explain their ranking during an interview. Factor analysis was used to identify patterns in the rankings of statements. We identified three distinct perspectives on payment reform in maternity care. One general perspective, broadly supported within the sector, focusing mainly on outcomes, and two complementary perspectives, one focusing more on equality and one focusing more on collaboration. This study shows there is consensus among stakeholders in maternity care in the Netherlands that payment reform is required. However, stakeholders have different views on the purpose and desired design of the payment reform and set different conditions. Working towards payment reform in co-creation with all involved parties may improve the general attitude towards payment reform, may enhance the level of trust among stakeholders, and may contribute to a higher uptake in practice.</p

    Positive and negative outcomes of informal caregiving at home and in institutionalised long-term care: A cross-sectional study

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    Background: Our ageing society is putting tremendous strain on public health and welfare programs to meet the needs of ageing individuals. Promoting informal caregiving is one way for policymakers to reduce this burden. However, caregiving may be experienced as stressful and is associated with adverse health consequences. While quite a lot of research focuses on caregiving for community-dwelling older adults, little is known about informal care in institutionalised long-term care (ILTC). Therefore, the objectives of this study were: 1) to compare characteristics of informal caregivers and care receivers and caregiver outcomes - at home and in ILTC; 2) to study the association between these characteristics and positive and negative caregiver outcomes; 3) to investigate the moderating effect of the setting (at home vs. ILTC) on these associations. Methods: A cross-sectional study was conducted using the TOPICS-MDS DataSet. A total of 5197 Dutch dyads were included. The average age of the care receivers and caregivers was respectively 80.7 years and 63.2 years. Several sociodemographic, health-related and caregiving-related characteristics of care receiver and caregiver and two caregiver outcomes (i.e., subjective burden and care-related quality of life) were included in the analyses. Results: Caregivers in both settings experienced comparable levels of subjective burden. Caregivers at home had slightly lower care-related quality of life than caregivers in ILTC. Several care receiver characteristics (i.e., male sex, married/cohabiting, more morbidities/disability, and less self-perceived health/psychological wellbeing) and several caregiver characteristics (i.e., female sex, being younger, living together with the care receiver, more objective burden, less self-perceived health, and more support) were associated with an increase in burden and/or a decrease in care-related quality of life. Some of these associations were stronger for dyads at home compared to dyads in ILTC. Conclusions: Informal caregiving does not stop with admission to an ILTC facility. Both settings need an informal caregiving policy, which is (1) tailored to the individual characteristics of care receivers and caregivers; (2) pays attention to the identified risk groups; and (3) reduces the negative caregiver outcomes and emphasizes the positive outcomes at the same time

    A new test of the construct validity of the CarerQol instrument: measuring the impact of informal care giving

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    Purpose: Most economic evaluations of health care programmes do not consider the effects of informal care, while this could lead to suboptimal policy decisions. This study investigates the construct validity of the CarerQol instrument, which measures and values carer effects, in a new population of informal caregivers. Methods: A questionnaire was distributed by mail (n = 1,100, net response rate = 21%) to regional informal care support centers throughout the Netherlands. Two types of construct validity, i.e., convergent and clinical validity, have been analyzed. Convergent validity was assessed with Spearman's correlation coefficients and multivariate correlation between the burden dimensions (CarerQol-7D) and the valuation component (CarerQol-VAS) of the CarerQol. Additionally, convergent validity was analyzed with Spearman's correlation coefficients between the CarerQol and other measures of subjective caregiver burden (SRB, PU). Clinical validity was evaluated with multivariate correlation between CarerQol-VAS and CarerQol-7D, characteristics of caregivers, care recipients and care situation among the whole sample of caregivers and subgroups. Results: The positive (negative) dimensions of CarerQol-7D were positively (negatively) related to CarerQol-VAS, and almost all had moderate strength of convergent validity. CarerQol-VAS was positively associated with PU and negatively with SRB. The CarerQol-VAS reflects differences in important background characteristics of informal care: type of relationship, age of the care recipient and duration of care giving were associated with higher CarerQol-VAS scores. These results confirmed earlier tests of the construct validity of the CarerQol. Furthermore, the dimensions of CarerQol-7D significantly explained differences in CarerQol-VAS scores among subgroups of carers. Conclusion: Notwithstanding the limitations of our study, such as the low response rate, this study shows that the CarerQol provides a valid means to measure carer effects for use in economic evaluations. Future research should derive a valuation set for the CarerQol and further address the instrument's content validity, sensitivity and reliability

    Cartan subalgebras in C*-algebras of Hausdorff etale groupoids

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    The reduced CC^*-algebra of the interior of the isotropy in any Hausdorff \'etale groupoid GG embeds as a CC^*-subalgebra MM of the reduced CC^*-algebra of GG. We prove that the set of pure states of MM with unique extension is dense, and deduce that any representation of the reduced CC^*-algebra of GG that is injective on MM is faithful. We prove that there is a conditional expectation from the reduced CC^*-algebra of GG onto MM if and only if the interior of the isotropy in GG is closed. Using this, we prove that when the interior of the isotropy is abelian and closed, MM is a Cartan subalgebra. We prove that for a large class of groupoids GG with abelian isotropy---including all Deaconu--Renault groupoids associated to discrete abelian groups---MM is a maximal abelian subalgebra. In the specific case of kk-graph groupoids, we deduce that MM is always maximal abelian, but show by example that it is not always Cartan.Comment: 14 pages. v2: Theorem 3.1 in v1 incorrect (thanks to A. Kumjain for pointing out the error); v2 shows there is a conditional expectation onto MM iff the interior of the isotropy is closed. v3: Material (including some theorem statements) rearranged and shortened. Lemma~3.5 of v2 removed. This version published in Integral Equations and Operator Theor
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