The Symplectic Penrose Kite

The purpose of this article is to view the Penrose kite from the perspective of symplectic geometry.Comment: 24 pages, 7 figures, minor changes in last version, to appear in Comm. Math. Phys

Elementi di statistica per lo studio della sociologa. Primi approcci per la ricerca in campo sociale

Concepito per far acquisire agli studenti universitari cognizioni circa l’importanza di un approccio rigoroso e razionale per le scienze umane e sociali, obiettivo del volume è far comprendere che un orientamento logico-matematico non è alternativo bensì complementare ed integrativo per lo studio della sociologia. Si tratta quindi di un testo scritto per spiegare l’utilità dell’apprendimento della statistica all’interno degli studi umanistici e, in particolare, per accompagnare e in un certo senso rendere più “concrete” le spiegazioni sul fondamento, i contenuti e la missione scientifica della sociologia. Sulla scorta di questo proposito, il convincimento che ispira l’organizzazione degli argomenti trattati è che, più che la statistica in quanto tale, è la statistica in quanto strumento a rappresentare un indispensabile ausilio per introdurre i temi dell’epistemologia, ossia per chiarire le questioni legate alla necessità/opportunità di una compenetrazione e commistione tra umanesimo e scienze cosiddette esatte. Per tale ragione il volume, articolato in sette capitoli, cerca di unire lo studio della sociologia a quello della metodologia della ricerca sociale. Cosicché, dopo un primo capitolo introduttivo, i capitoli secondo e terzo trattano della costruzione del disegno della ricerca, ovvero forniscono una descrizione delle principali fasi della rilevazioni dei dati nonché della presentazione degli stessi, evidenziandone gli aspetti metodologici, mentre nei restanti capitoli vengono presentati, con il ricorso a molti esempi pratici, gli strumenti fondamentali per l’analisi dei dati (rapporti statistici, valori medi, variabilità e relazioni tra variabili)

Cost-effectiveness of eye care services in Zambia.

OBJECTIVE: To estimate the cost-effectiveness of cataract surgery and refractive error/presbyopia correction in Zambia. METHODS: Primary data on costs and health related quality of life were collected in a prospective cohort study of 170 cataract and 113 refractive error/presbyopia patients recruited from three health facilities. Six months later, follow-up data were available from 77 and 41 patients who had received cataract surgery and spectacles, respectively. Costs were determined from patient interviews and micro-costing at the three health facilities. Utility values were gathered by administering the EQ-5D quality of life instrument immediately before and six months after cataract surgery or acquiring spectacles. A probabilistic state-transition model was used to generate cost-effectiveness estimates with uncertainty ranges. RESULTS: Utility values significantly improved across the patient sample after cataract surgery and acquiring spectacles. Incremental costs per Quality Adjusted Life Years gained were US$259 for cataract surgery and US$ 375 for refractive error correction. The probabilities of the incremental cost-effectiveness ratios being below the Zambian gross national income per capita were 95% for both cataract surgery and refractive error correction. CONCLUSION: In spite of proven cost-effectiveness, severe health system constraints are likely to hamper scaling up of the interventions

Convex Polytopes and Quasilattices from the Symplectic Viewpoint

We construct, for each convex polytope, possibly nonrational and nonsimple, a family of compact spaces that are stratified by quasifolds, i.e. each of these spaces is a collection of quasifolds glued together in an suitable way. A quasifold is a space locally modelled on $\R^k$ modulo the action of a discrete, possibly infinite, group. The way strata are glued to each other also involves the action of an (infinite) discrete group. Each stratified space is endowed with a symplectic structure and a moment mapping having the property that its image gives the original polytope back. These spaces may be viewed as a natural generalization of symplectic toric varieties to the nonrational setting.Comment: LaTeX, 29 pages. Revised version: TITLE changed, reorganization of notations and exposition, added remarks and reference

Interplay of the nuclear envelope with chromatin in physiology and pathology

The nuclear envelope compartmentalizes chromatin in eukaryotic cells. The main nuclear envelope components are lamins that associate with a panoply of factors, including the LEM domain proteins. The nuclear envelope of mammalian cells opens up during cell division. It is reassembled and associated with chromatin at the end of mitosis when telomeres tether to the nuclear periphery. Lamins, LEM domain proteins, and DNA binding factors, as BAF, contribute to the reorganization of chromatin. In this context, an emerging role is that of the ESCRT complex, a machinery operating in multiple membrane assembly pathways, including nuclear envelope reformation. Research in this area is unraveling how, mechanistically, ESCRTs link to nuclear envelope associated factors as LEM domain proteins. Importantly, ESCRTs work also during interphase for repairing nuclear envelope ruptures. Altogether the advances in this field are giving new clues for the interpretation of diseases implicating nuclear envelope fragility, as laminopathies and cancer

Informing Balanced Investment in Services and Health Systems: A Case Study of Priority Setting for Tuberculosis Interventions in South Africa.

OBJECTIVES: Health systems face nonfinancial constraints that can influence the opportunity cost of interventions. Empirical methods to explore their impact, however, are underdeveloped. We develop a conceptual framework for defining health system constraints and empirical estimation methods that rely on routine data. We then present an empirical approach for incorporating nonfinancial constraints in cost-effectiveness models of health benefit packages for the health sector. METHODS: We illustrate the application of this approach through a case study of defining a package of services for tuberculosis case-finding in South Africa. An economic model combining transmission model outputs with unit costs was developed to examine the cost-effectiveness of alternative screening and diagnostic algorithms. Constraints were operationalized as restrictions on achievable coverage based on: (1) financial resources; (2) human resources; and (3) policy constraints around diagnostics purchasing. Cost-effectiveness of the interventions was assessed under one "unconstrained" and several "constrained" scenarios. For the unconstrained scenario, incremental cost-effectiveness ratios were estimated with and without the costs of "relaxing" constraints. RESULTS: We find substantial differences in incremental cost-effectiveness ratios across scenarios, leading to variations in the decision rules for prioritizing interventions. In constrained scenarios, the limiting factor for most interventions was not financial, but rather the availability of human resources. CONCLUSIONS: We find that optimal prioritization among different tuberculosis control strategies in South Africa is influenced by whether and how constraints are taken into consideration. We thus demonstrate both the importance and feasibility of considering nonfinancial constraints in health sector resource allocation models

Activation of NF-kappaB/Rel transcription factors in human primary peripheral blood mononuclear cells by interleukin 7.

Pathways that regulate the activation of NF-kappaB/Rel transcription factors are known to include signaling through a number of cytokine receptors. Interleukin 7 (IL-7), produced by bone marrow and other stromal cells, is a key factor for differentiation and survival in the lymphoid and other compartments. We found that human recombinant IL-7 induced NF-kappaB/Rel activation, analyzed by electrophoretic mobility shift assay (EMSA), in human peripheral blood T lymphocytes from healthy donors. Induced complexes included p65 and p50 NF-kappaB/Rel subunits. These results demonstrate for the first time that IL-7 can participate in signaling leading to NF-kappaB/Rel activation

Effects of dog-assisted therapies on cognitive mnemonic capabilities in people affected by Alzheimer's disease

Alzheimer’s disease (AD) is the most common cause of dementia in humans and, currently, a valid treatment is lacking. Our goal is to demonstrate the importance and benefits of the relationship with companion animals (considered as co-therapists), intended as a means of facilitating social relations and promoting evident wellbeing in AD patients. The study involved 30 randomly chosen patients with Alzheimer’s disease (group T) and three dogs. The group participated in a total of 24 animal-assisted interventions (AAIs) sessions over a span of 12 weeks, using the Mini-Mental State Examination (MMSE), Wellness and Cognitive Ability Questionnaire (Brief Assessment Cognition or BAC), and Alzheimer’s Disease Assessment Scale (ADAS) as assessment tests. A second group (group C), consisting of 10 people with AD, was enrolled as control group and underwent the same assessment tests but did not benefit from the presence of the dogs. Tests were carried out at time T0 (before starting sessions), T1 (end of sessions), and T2 (two months after last session). People belonging to group T achieved an overall improvement in their perceived state of wellbeing, even on a cognitive and mnemonic plane. However, two months after the end of the sessions, the test results in people suffering from AD decreased towards the baseline (T0). The study shows how such progress can be achieved through activities based on the relationship with an animal, as long as the animal is a steady presence in the life of the patient receiving the intervention. Dogs involved in other dog-assisted therapies have been found suitable also for assisting patients with AD