Inflations of geometric grid classes of permutations

All three authors were partially supported by EPSRC via the grant EP/J006440/1.Geometric grid classes and the substitution decomposition have both been shown to be fundamental in the understanding of the structure of permutation classes. In particular, these are the two main tools in the recent classification of permutation classes of growth rate less than κ ≈ 2.20557 (a specific algebraic integer at which infinite antichains first appear). Using language- and order-theoretic methods, we prove that the substitution closures of geometric grid classes are well partially ordered, finitely based, and that all their subclasses have algebraic generating functions. We go on to show that the inflation of a geometric grid class by a strongly rational class is well partially ordered, and that all its subclasses have rational generating functions. This latter fact allows us to conclude that every permutation class with growth rate less than κ has a rational generating function. This bound is tight as there are permutation classes with growth rate κ which have nonrational generating functions.PostprintPeer reviewe

Connecting Terminals and 2-Disjoint Connected Subgraphs

Given a graph $G=(V,E)$ and a set of terminal vertices $T$ we say that a superset $S$ of $T$ is $T$-connecting if $S$ induces a connected graph, and $S$ is minimal if no strict subset of $S$ is $T$-connecting. In this paper we prove that there are at most ${|V \setminus T| \choose |T|-2} \cdot 3^{\frac{|V \setminus T|}{3}}$ minimal $T$-connecting sets when $|T| \leq n/3$ and that these can be enumerated within a polynomial factor of this bound. This generalizes the algorithm for enumerating all induced paths between a pair of vertices, corresponding to the case $|T|=2$. We apply our enumeration algorithm to solve the {\sc 2-Disjoint Connected Subgraphs} problem in time $O^*(1.7804^n)$, improving on the recent $O^*(1.933^n)$ algorithm of Cygan et al. 2012 LATIN paper.Comment: 13 pages, 1 figur

Psychosocial therapy for Parkinson's-related dementia: intervention development.

Background: Group-based psychosocial therapy, such as group Cognitive Stimulation Therapy, improves cognition and quality of life in people living with dementia. Neuropsychiatric symptoms and restricted mobility are common complications for people with Parkinson's-related dementia (PRD) and may limit access to, and participation in, group activities. This study describes the development of a condition-specific, home-based psychosocial therapy for people with PRD ready to be trialled in a clinical population. Methods: By means of a multistage process, a draft therapy manual was developed in an iterative manner through collaboration with medical experts, researchers and Patient and Public Involvement (PPI) representatives. In stage 1, an extensive literature search of psychosocial therapies for dementia with potential relevance for Parkinson's disease (PD) was undertaken to select a candidate therapy for adaptation. In stage 2, qualitative feedback from stakeholders and intelligence regarding existing nonpharmacological therapies for cognitive impairment in PD was combined to produce a prototype therapy manual. In stage 3, the manual was field tested in: 1) a home-setting using a 25-item assessment tool; and 2) at a local PD support group with PPI representatives. Based on the feedback from this phase, final design modifications were implemented and a draft therapy manual produced. Results: The manual was developed in an iterative manner. Interview and focus group transcripts identified three enduring themes: manual form and content, therapy acceptability by people with PRD, and companion guidance and support. Major adaptations included: removal of discrete levels of task complexity, removal of images that were potentially hallucinogenic or lacked clarity, and updating of the content. Conclusion: We have successfully developed a Cognitive Stimulation Therapy-based psychosocial therapy specifically adapted for people with PRD. The therapy is ready to trial in a pilot randomized controlled study

Patterns of democracy: Coalition governance and majoritarian modification in the United Kingdom, 2010–2015

The UK is often regarded as the archetype of Westminster democracy and as the empirical antithesis of the power-sharing coalitions of Western Europe. Yet, in recent years a different account has emerged that focuses on the subtler institutional dynamics which limit the executive. It is to this body of scholarship that this article responds, locating the recent chapter of coalition government within the wider context of the UK’s democratic evolution. To do so, the article draws Lijphart’s two-dimensional typology of democracies, developing a refined framework that enables systematic comparison over time. The article demonstrates that between over the course of the 2010-15 Parliament, the UK underwent another period of majoritarian modification, driven by factors including the long-term influence of the constitutional forces unleashed under Labour and the short-term impact of coalition management. The article makes several important contributions, salient in the UK and beyond. Theoretically, it offers a critical rejoinder to debates regarding the relationship between institutional design and democratic performance. Methodologically, it demonstrates that the tools of large-scale comparison can be effectively scaled-down to facilitate withincase analysis. Empirically, it provides a series of conclusions regarding the tenability of the UK’s extant democratic architecture under the weight of pressures to which it continues to be subject

Parkinson’s-adapted cognitive stimulation therapy: a pilot randomized controlled clinical trial

© The Author(s), 2019. Cognitive stimulation therapy (CST) is widely used with people with dementia, but there is no evidence of its efficacy in mild cognitive impairment or dementia in Parkinson’s disease (PD-MCI; PDD) or dementia with Lewy bodies (DLB). We aimed to explore the impact of ‘CST-PD’, which is home-based, individualized CST adapted for this population. In a single-blind, randomized controlled exploratory pilot trial (RCT), we randomized 76 participant–dyads [PD-MCI (n = 15), PDD (n = 40), DLB (n = 21) and their care partners] to CST-PD or treatment as usual (TAU). CST-PD involves home-based cognitively stimulating and engaging activities delivered by a trained care partner. Exploratory outcomes at 12 weeks included cognition (Addenbrooke’s Cognitive Evaluation; ACE-III), neuropsychiatric symptoms and function. In care partners, we assessed burden, stress and general health status. Relationship quality and quality of life were assessed in both dyad members. At 12 weeks, the ACE-III showed a nonstatistically significant improvement in the CST-PD group compared with the TAU group, although neuropsychiatric symptoms increased significantly in the former. In contrast, care partners’ quality of life (d = 0.16) and relationship quality (‘satisfaction’, d = 0.01; ‘positive interaction’, d = 0.55) improved significantly in the CST-PD group, and care burden (d = 0.16) and stress (d = 0.05) were significantly lower. Qualitative findings in the CST-PD recipients revealed positive ‘in the moment’ responses to the intervention, supporting the quantitative results. In conclusion, care-partner-delivered CST-PD may improve a range of care-partner outcomes that are important in supporting home-based care. A full-scale follow-up RCT to evaluate clinical and cost effectiveness is warranted

A Novel Intravital Method to Evaluate Cerebral Vasospasm in Rat Models of Subarachnoid Hemorrhage: A Study with Synchrotron Radiation Angiography

Precise in vivo evaluation of cerebral vasospasm caused by subarachnoid hemorrhage has remained a critical but unsolved issue in experimental small animal models. In this study, we used synchrotron radiation angiography to study the vasospasm of anterior circulation arteries in two subarachnoid hemorrhage models in rats. Synchrotron radiation angiography, laser Doppler flowmetry-cerebral blood flow measurement, [125I]N-isopropyl-p-iodoamphetamine cerebral blood flow measurement and terminal examinations were applied to evaluate the changes of anterior circulation arteries in two subarachnoid hemorrhage models made by blood injection into cisterna magna and prechiasmatic cistern. Using synchrotron radiation angiography technique, we detected cerebral vasospasm in subarachnoid hemorrhage rats compared to the controls (p<0.05). We also identified two interesting findings: 1) both middle cerebral artery and anterior cerebral artery shrunk the most at day 3 after subarachnoid hemorrhage; 2) the diameter of anterior cerebral artery in the prechiasmatic cistern injection group was smaller than that in the cisterna magna injection group (p<0.05), but not for middle cerebral artery. We concluded that synchrotron radiation angiography provided a novel technique, which could directly evaluate cerebral vasospasm in small animal experimental subarachnoid hemorrhage models. The courses of vasospasm in these two injection models are similar; however, the model produced by prechiasmatic cistern injection is more suitable for study of anterior circulation vasospasm

Processos de democracia direta: sim ou não? Os argumentos clássicos à luz da teoria e da prática

Regularmente surgem controvérsias sobre os processos de democracia direta, dos quais os mecanismos mais frequentes são a iniciativa popular, o plebiscito e o referendo. Por um lado, há autores que defendem a posição de que essas instituições tornam o jogo político mais lento, caro, confuso e ilegítimo; outros defendem a posição contrária e argumentam que processos de democracia direta são fundamentais para os cidadãos e a qualidade da democracia. O presente estudo analisa esse tema em torno de sete questões, baseadas em considerações teóricas e pesquisas empíricas: 1. A questão entre o minimalismo e o maximalismo democrático; 2. A concorrência entre maioria e minoria; 3. A concorrência entre as instituições representativas e os processos de democracia direta; 4. A questão da competência dos cidadãos; 5. A questão dos efeitos colaterais dos processos de democracia direta; 6. A questão do tamanho do eleitorado; 7. A questão dos custos dos processos de democracia direta. As sete questões são analisadas a partir de uma revisão bibliográfica que considera tanto fontes nacionais como internacionais. O estudo mostra que os processos de democracia direta podem ser um complemento para as instituições representativas em um sistema democrático. O bom desempenho dos plebiscitos, referendos e iniciativas populares depende tanto da regulamentação destes como também do desempenho das outras instituições políticas e da situação socioeconômica de um país. O estudo permite ampliar e aprofundar o debate sobre processos de democracia direta no Brasil