Resummation of perturbation series and reducibility for Bryuno skew-product flows

We consider skew-product systems on T^d x SL(2,R) for Bryuno base flows close to constant coefficients, depending on a parameter, in any dimension d, and we prove reducibility for a large measure set of values of the parameter. The proof is based on a resummation procedure of the formal power series for the conjugation, and uses techniques of renormalisation group in quantum field theory.Comment: 30 pages, 12 figure

Nutrient Considerations for Plants Grown Under Space Flight Conditions

We present here results on the analysis of 100 mL medium samples extracted from sterilized foam (Smithers-Oasis, Kent OH) used to support the growth of both dicotyledonous (Haplopappus gracilis, n=75) and monocotyledonous (Hemerocallis cv Autumn Blaze, n=25) aseptic plants in NASA's Plant Growth Unit (PGU) during the 5-day CHROMEX-01 Space Shuttle flight (March 1989, STS-29). At recovery, the medium remaining within each of the five floral foam blocks (for both the space flight and ground control experiments) was extracted under vacuum, filtered and subjected to elemental analyses. Concentration levels of some elements remained the same, while some decreased and others increased. A unique aspect of this experiment was that all plants were either aseptic tissue culture generated plantlets or sterile seedling clones, and the design of the PGU facilitated the maintenance of asepsis throughout the mission (confirmed by postflight microbial sampling). This permitted the elimination of microbial considerations in the interpretation of the data. The significance of these findings for growing plants in altered gravity environments are discussed

Microfilaments and actin-associated proteins at sites of membrane-substrate attachment within acetylcholine receptor clusters

Rat myotubes in tissue culture form broad areas of close contact with the substrate. These areas often display two distinct, interdigitating sets of membrane domains. One, the "contact domain", is close to the substrate; the other, termed the "AChR domain", is further from the substrate and is rich in acetylcholine receptors (AChR). We have used fluorescence techniques to study the organization of the cytoskeleton in these areas. Substrate-apposed membrane of the myotubes was exposed either by shearing or by permeabilizing the cells with a neutral detergent. Phalloidin derivatives and affinity-purified polyclonal or monoclonal antibodies specific for cytoskeletal proteins were then applied to the samples. Sheared samples were observed by epifluorescence microscopy; detergent-permeabilized samples were observed by total internal reflection fluorescence microscopy. We found that, like antivinculin, fluorescent phalloidin derivatives and antibodies to [alpha]-actinin, filamin, and talin preferentially labeled the contact domains. This suggests that bundles of microfilaments associate with the membrane at sites of myotubesubstrate attachment. In contrast, a 43K protein, closely associated with AChR, was present only at AChR domains. A monoclonal antibody to actin labeled both AChR and contact domains, suggesting that actin is enriched over both regions. Our results suggest that, like the plasma membrane of AChR clusters, the underlying membrane skeleton is organized into at least two distinct domains.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/27926/1/0000350.pd

A Nonperturbative Eliasson's Reducibility Theorem

This paper is concerned with discrete, one-dimensional Schr\"odinger operators with real analytic potentials and one Diophantine frequency. Using localization and duality we show that almost every point in the spectrum admits a quasi-periodic Bloch wave if the potential is smaller than a certain constant which does not depend on the precise Diophantine conditions. The associated first-order system, a quasi-periodic skew-product, is shown to be reducible for almost all values of the energy. This is a partial nonperturbative generalization of a reducibility theorem by Eliasson. We also extend nonperturbatively the genericity of Cantor spectrum for these Schr\"odinger operators. Finally we prove that in our setting, Cantor spectrum implies the existence of a $G_\delta$-set of energies whose Schr\"odinger cocycle is not reducible to constant coefficients

Global dynamics of three species omnivory models with Lotka-Volterra interaction

[[abstract]]In this work, we consider the community of three species food web model with Lotka-Volterra type predator-prey interaction. In the absence of other species, each species follows the traditional logistical growth model and the top predator is an omnivore which is defined as feeding on the other two species. It can be seen as a model with one basal resource and two generalist predators, and pairwise interactions of all species are predator-prey type. It is well known that the omnivory module blends the attributes of several well-studied community modules, such as food chains (food chain models), exploitative competition (two predators-one prey models), and apparent competition (one predator-two preys models). With a mild biological restriction, we completely classify all parameters. All local dynamics and most parts of global dynamics are established corresponding to the classification. Moreover, the whole system is uniformly persistent when the unique coexistence appears. Finally, we conclude by discussing the strategy of inferior species to survive and the mechanism of uniform persistence for the three species ecosystem.[[notice]]補正完

Which executive functioning deficits are associated with AD/HD, ODD/CD and comorbid AD/HD+ODD/CD?

Item does not contain fulltextThis study investigated (1) whether attention deficit/hyperactivity disorder (AD/HD) is associated with executive functioning (EF) deficits while controlling for oppositional defiant disorder/conduct disorder (ODD/CD), (2) whether ODD/CD is associated with EF deficits while controlling for AD/HD, and (3)~whether a combination of AD/HD and ODD/CD is associated with EF deficits (and the possibility that there is no association between EF deficits and AD/HD or ODD/CD in isolation). Subjects were 99~children ages 6–12 years. Three putative domains of EF were investigated using well-validated tests: verbal fluency, working memory, and planning. Independent of ODD/CD, AD/HD was associated with deficits in planning and working memory, but not in verbal fluency. Only teacher rated AD/HD, but not parent rated AD/HD, significantly contributed to the prediction of EF task performance. No EF deficits were associated with ODD/CD. The presence of comorbid AD/HD accounts for the EF deficits in children with comorbid AD/HD+ODD/CD. These results suggest that EF deficits are unique to AD/HD and support the model proposed by R. A. Barkley (1997).17 p

Riding on the Coat-Tails of Traditional Cultural Expressions

Matters related to the protection of traditional cultural expressions (‘TCEs’) or expressions of folklore (‘EoFs’) are sensitive and intricate as a blend of legal, economic, philosophical and anthropological considerations jostle to capture their core features. This results in disparate views surrounding what should qualify as TCEs or EoFs, who should be considered their ‘owner’ (assuming that ownership per se is conceptually compatible with these items), which is the most appropriate legal protection regime and how broad their scope of protection should be. Drawing from these various accounts on TCEs, this article focuses on the interaction between TCEs and EoFs originating on the European continent and the European Union (‘EU’) trade mark legislation. Specifically, this article examines whether the limitations of the effects of trade mark rights and of the absolute grounds of refusal, as developed by the case law of the Court of Justice of the European Union, are effective in preserving the cohesion of TCEs. This article advances the thesis that registration of TCEs and EoFs as trade marks generates an imbalance between the rights of the trade mark owner and the defences available to others under the EU trade mark law framework. Furthermore, such an imbalance is likely to hinder the unfettered circulation of TCEs and undermine their original meaning. Lastly, in some cases, trade mark registration of TCEs contributes to their appropriation and misappropriation. The article concludes that, de lege ferenda, the direct exclusion of TCEs as eligible subject matter for trade mark registration is preferable to seeking a post factum remedy

Structural cerebellar correlates of cognitive functions in spinocerebellar ataxia type 2

Spinocerebellar ataxia type 2 (SCA2) is an autosomal dominant neurodegenerative disease involving the cerebellum and characterized by a typical motor syndrome. In addition, the presence of cognitive impairment is now widely acknowledged as a feature of SCA2. Given the extensive connections between the cerebellum and associative cerebral areas, it is reasonable to hypothesize that cerebellar neurodegeneration associated with SCA2 may impact on the cerebellar modulation of the cerebral cortex, thus resulting in functional impairment. The aim of the present study was to investigate and quantitatively map the pattern of cerebellar gray matter (GM) atrophy due to SCA2 neurodegeneration and to correlate that with patients' cognitive performances. Cerebellar GM maps were extracted and compared between SCA2 patients (n = 9) and controls (n = 33) by using voxel-based morphometry. Furthermore, the relationship between cerebellar GM atrophy and neuropsychological scores of the patients was assessed. Specific cerebellar GM regions were found to be affected in patients. Additionally, GM loss in cognitive posterior lobules (VI, Crus I, Crus II, VIIB, IX) correlated with visuospatial, verbal memory and executive tasks, while additional correlations with motor anterior (V) and posterior (VIIIA, VIIIB) lobules were found for the tasks engaging motor and planning components. Our results provide evidence that the SCA2 neurodegenerative process affects the cerebellar cortex and that MRI indices of atrophy in different cerebellar subregions may account for the specificity of cognitive symptomatology observed in patients, as result of a cerebello-cerebral dysregulation

Development of a psychiatric disorder linked to cerebellar lesions

Cerebellar dysfunction plays a critical role in neurodevelopmental disorders with long-term behavioral and neuropsychiatric symptoms. A 43-year-old woman with a cerebellum arteriovenous malformation and history of behavioral dysregulation since childhood is described. After the rupture of the cerebellar malformation in adulthood, her behavior morphed into specific psychiatric symptoms and cognitive deficits occurred. The neuropsychological assessment evidenced impaired performance in attention, visuospatial, memory, and language domains. Moreover, psychiatric assessment indicated a borderline personality disorder. Brain MRI examination detected macroscopic abnormalities in the cerebellar posterior lobules VI, VIIa (Crus I), and IX, and in the posterior area of the vermis, regions usually involved in cognitive and emotional processing. The described patient suffered from cognitive and behavioral symptoms that are part of the cerebellar cognitive affective syndrome. This case supports the hypothesis of a cerebellar role in personality disorders emphasizing the importance of also examining the cerebellum in the presence of behavioral disturbances in children and adults