A facile synthetic method to prepare fluorescently labeled ROMP polymers

[structure: see text] To probe the activities of sperm ADAM protein (fertilinbeta), we devised a general synthetic strategy to generate fluorescently labeled fertilinbeta oligopeptide polymers. Immunofluorescence studies with these polymers demonstrated that fertilinbeta polymers bind specifically to a protein receptor on the mouse egg plasma membrane.     

Regulation of stearoyl-CoA desaturase-1 after central and peripheral nerve lesions

Background  

Interruption of mature axons activates a cascade of events in neuronal cell bodies which leads to various outcomes from functional regeneration in the PNS to the failure of any significant regeneration in the CNS. One factor which seems to play an important role in the molecular programs after axotomy is the stearoyl Coenzyme A-desaturase-1 (SCD-1). This enzyme is needed for the conversion of stearate into oleate. Beside its role in membrane synthesis, oleate could act as a neurotrophic factor, involved in signal transduction pathways via activation of protein kinases C.     

Support Varieties for Selfinjective Algebras

Support varieties for any finite dimensional algebra over a field were introduced in (Proc. London Math. Soc. 88 (3) (2004) 705–732) using graded subalgebras of the Hochschild cohomology ring. We mainly study these varieties for selfinjective algebras under appropriate finite generation hypotheses. Then many of the standard results from the theory of support varieties for finite groups generalize to this situation. In particular, the complexity of the module equals the dimension of its corresponding variety, all closed homogeneous varieties occur as the variety of some module, the variety of an indecomposable module is connected, the variety of periodic modules are lines and for symmetric algebras a generalization of Webbs theorem is true. As a corollary of a more general result we show that Webbs theorem generalizes to finite dimensional cocommutative Hopf algebras.Received November 2003Mathematics Subject Classifications (2000) Primary: 16E40, 16G10, 16P10, 16P20; Secondary: 16G70.     

Ideals in a perfect closure, linear growth of primary decompositions, and tight closure

This paper is concerned with tight closure in a commutative Noetherian ring of prime characteristic , and is motivated by an argument of K. E. Smith and I. Swanson that shows that, if the sequence of Frobenius powers of a proper ideal of has linear growth of primary decompositions, then tight closure (of ) `commutes with localization at the powers of a single element'. It is shown in this paper that, provided has a weak test element, linear growth of primary decompositions for other sequences of ideals of that approximate, in a certain sense, the sequence of Frobenius powers of would not only be just as good in this context, but, in the presence of a certain additional finiteness property, would actually imply that tight closure (of ) commutes with localization at an arbitrary multiplicatively closed subset of .

Work of M. Katzman on the localization problem for tight closure raised the question as to whether the union of the associated primes of the tight closures of the Frobenius powers of has only finitely many maximal members. This paper develops, through a careful analysis of the ideal theory of the perfect closure of , strategies for showing that tight closure (of a specified ideal of ) commutes with localization at an arbitrary multiplicatively closed subset of and for showing that the union of the associated primes of the tight closures of the Frobenius powers of is actually a finite set. Several applications of the strategies are presented; in most of them it was already known that tight closure commutes with localization, but the resulting affirmative answers to Katzman's question in the various situations considered are believed to be new.

     

Random Euclidean embeddings in spaces of bounded volume ratio

Let $\text{(}\text{R}{}^{\mathrm{N}}\text{,6·6)}$ be the space $\text{R}{}^{\mathrm{N}}$ equipped with a norm 6·6 whose unit ball has a bounded volume ratio with respect to the Euclidean unit ball. Let Γ be any random N×n matrix with N>n, whose entries are independent random variables satisfying some moment assumptions. We show that with high probability Γ is a good isomorphism from the n-dimensional Euclidean space $\text{(}\text{R}{}^{\mathrm{n}}\text{,|·|)}$ onto its image in $\text{(}\text{R}{}^{\mathrm{N}}\text{,6·6)}$: there exist α,β>0 such that for all $\text{x∈}\text{R}{}^{\mathrm{n}}$, $\text{α}\text{N}\text{|x|?6Γx6?β}\text{N}\text{|x|}$. This solves a conjecture of Schechtman on random embeddings of ?₂ⁿ into ?₁^N. To cite this article: A. Litvak et al., C. R. Acad. Sci. Paris, Ser. I 339 (2004).     

Integrated fluidic adaptive zoom lens

An integrated fluidic adaptive zoom lens is demonstrated for what is believed to be the first time. A zoom lens was fabricated using an UV lithographic-galvanic-like process involving soft lithography and wafer bonding. The zooming capability of such a lens was achieved by varying the focal length instead of the distance between the lenses. A zoom ratio of greater than 2 was obtained for devices that are 8 mm thick and have a 20-mm lens diameter. Including the 30-mm image distance, the total physical length of the fluidic zoom lens was less than 43 mm. More-compact systems with a higher zoom ratio can be obtained by reduction of the aperture size.     

An analytical and experimental comparison of optimal actuator and error sensor location for vibration attenuation

Feedforward active control of the flexural waves in a single and L-shaped plate has been analytically and experimentally investigated. The plates are simply supported along two parallel edges, and free at the other two ends. Point forces were used to generate the primary and secondary plate excitations. The plate flexural displacement is described by a combination of a travelling wave solution and a modal expansion. The flexural wave coefficients were determined using the boundary conditions, continuity equations at the driving force locations, and continuity equations at the corner junction for the L-shaped plate. The control actuator and error sensor are optimally located in order to achieve the best control performance.     

Functional MRI of working memory and selective attention in vibrotactile frequency discrimination

Background  

Focal lesions of the frontal, parietal and temporal lobe may interfere with tactile working memory and attention. To characterise the neural correlates of intact vibrotactile working memory and attention, functional MRI was conducted in 12 healthy young adults. Participants performed a forced-choice vibrotactile frequency discrimination task, comparing a cue stimulus of fixed frequency to their right thumb with a probe stimulus of identical or higher frequency. To investigate working memory, the time interval between the 2 stimuli was pseudo-randomized (either 2 or 8 s). To investigate selective attention, a distractor stimulus was occasionally presented contralaterally, simultaneous to the probe.