Characterization and sensor application of cellulose electro-active paper （EAPap）

As a novel piezoelectric material, the mechanical and piezoelectric properties of cellulose electro-active paper （EAPap） were studied. Young＇s modulus of piezoelectric EAPap was dependant on the material orientation as compared with other EAP materials. The highest Young＇s modulus was obtained at 0° direction, while the highest direct piezoelectric charge constant was achieved at 45°. By measuring the induced output voltage from the thin piezoelectric cellulose film under the applied impact force, we demonstrate that piezoelectric EAPap film has a potential for sensor applications.     

Inverting generating functions with increased numerical precision �� A computational experience

In this paper, we consider the numerical inversion of a variety of generating functions (GFs) that arise in the area of engineering and non-engineering fields. Three classes of GFs are taken into account in a comprehensive manner: classes of probability generating functions (PGFs) that are given in rational and non-rational forms, and a class of GFs that are not PGFs. Among others, those PGFs that are not explicitly given but contain a number of unknowns are largely considered as they are often encountered in many interesting applied problems. For the numerical inversion of GFs, we use the methods of the discrete (fast) Fourier transform and the Taylor series expansion. Through these methods, we show that it is remarkably easy to obtain the desired sequence to any given accuracy, so long as enough numerical precision is used in computations. Since high precision is readily available in current software packages and programming languages, one can now lift, with little effort, the so-called Laplacian curtain that veils the sequence of interest. To demonstrate, we take a series of representative examples: the PGF of the number of customers in the discrete-time GeoX/Geo/c queue, the same in the continuous-time MX/D/c queue, and the GFs arising in the discrete-time renewal process.     

Towards a Medium/High Load-Bearing Scaffold Fabrication System

This paper describes fabrication of scaffolds for load-bearing applications, with primary consideration from the manufacturing perspective. An extrusion device, inspired by the FDM process, was used to create scaffolds from a variety of different polymeric materials and mixtures. The effectiveness of these scaffolds to host cells for bone regeneration has been investigated. This ongoing work has generated significant insight into the future direction of research and the possibilities of developing scaffolds for medium/high load-bearing applications.     

Smad4 signalling in T cells is required for suppression of gastrointestinal cancer

SMAD4 (MAD homologue 4 (Drosophila)), also known as DPC4 (deleted in pancreatic cancer), is a tumour suppressor gene that encodes a central mediator of transforming growth factor-beta signalling. Germline mutations in SMAD4 are found in over 50% of patients with familial juvenile polyposis, an autosomal dominant disorder characterized by predisposition to hamartomatous polyps and gastrointestinal cancer. Dense inflammatory cell infiltrates underlay grossly normal appearing, non-polypoid colonic and gastric mucosa of patients with familial juvenile polyposis. This prominent stromal component suggests that loss of SMAD4-dependent signalling in cells within the epithelial microenvironment has an important role in the evolution of intestinal tumorigenesis in this syndrome. Here we show that selective loss of Smad4-dependent signalling in T cells leads to spontaneous epithelial cancers throughout the gastrointestinal tract in mice, whereas epithelial-specific deletion of the Smad4 gene does not. Tumours arising within the colon, rectum, duodenum, stomach and oral cavity are stroma-rich with dense plasma cell infiltrates. Smad4(-/-) T cells produce abundant T(H)2-type cytokines including interleukin (IL)-5, IL-6 and IL-13, known mediators of plasma cell and stromal expansion. The results support the concept that cancer, as an outcome, reflects the loss of the normal communication between the cellular constituents of a given organ, and indicate that Smad4-deficient T cells ultimately send the wrong message to their stromal and epithelial neighbours.     

Space geodesy: subsidence and flooding in New Orleans

It has long been recognized that New Orleans is subsiding and is therefore susceptible to catastrophic flooding. Here we present a new subsidence map for the city, generated from space-based synthetic-aperture radar measurements, which reveals that parts of New Orleans underwent rapid subsidence in the three years before Hurricane Katrina struck in August 2005. One such area is next to the Mississippi River-Gulf Outlet (MRGO) canal, where levees failed during the peak storm surge: the map indicates that this weakness could be explained by subsidence of a metre or more since their construction.     

Long-term eruptive activity at a submarine arc volcano

Three-quarters of the Earth's volcanic activity is submarine, located mostly along the mid-ocean ridges, with the remainder along intraoceanic arcs and hotspots at depths varying from greater than 4,000 m to near the sea surface. Most observations and sampling of submarine eruptions have been indirect, made from surface vessels or made after the fact. We describe here direct observations and sampling of an eruption at a submarine arc volcano named NW Rota-1, located 60 km northwest of the island of Rota (Commonwealth of the Northern Mariana Islands). We observed a pulsating plume permeated with droplets of molten sulphur disgorging volcanic ash and lapilli from a 15-m diameter pit in March 2004 and again in October 2005 near the summit of the volcano at a water depth of 555 m (depth in 2004). A turbid layer found on the flanks of the volcano (in 2004) at depths from 700 m to more than 1,400 m was probably formed by mass-wasting events related to the eruption. Long-term eruptive activity has produced an unusual chemical environment and a very unstable benthic habitat exploited by only a few mobile decapod species. Such conditions are perhaps distinctive of active arc and hotspot volcanoes.     

Rec8 phosphorylation and recombination promote the step-wise loss of cohesins in meiosis

During meiosis, cohesins--protein complexes that hold sister chromatids together--are lost from chromosomes in a step-wise manner. Loss of cohesins from chromosome arms is necessary for homologous chromosomes to segregate during meiosis I. Retention of cohesins around centromeres until meiosis II is required for the accurate segregation of sister chromatids. Here we show that phosphorylation of the cohesin subunit Rec8 contributes to step-wise cohesin removal. Our data further implicate two other key regulators of meiotic chromosome segregation, the cohesin protector Sgo1 and meiotic recombination in bringing about the step-wise loss of cohesins and thus the establishment of the meiotic chromosome segregation pattern. Understanding the interplay between these processes should provide insight into the events underlying meiotic chromosome mis-segregation, the leading cause of miscarriages and mental retardation in humans.     

Mitochondrial dysfunction in Drosophila PINK1 mutants is complemented by parkin

Autosomal recessive juvenile parkinsonism (AR-JP) is an early-onset form of Parkinson's disease characterized by motor disturbances and dopaminergic neurodegeneration. To address its underlying molecular pathogenesis, we generated and characterized loss-of-function mutants of Drosophila PTEN-induced putative kinase 1 (PINK1), a novel AR-JP-linked gene. Here, we show that PINK1 mutants exhibit indirect flight muscle and dopaminergic neuronal degeneration accompanied by locomotive defects. Furthermore, transmission electron microscopy analysis and a rescue experiment with Drosophila Bcl-2 demonstrated that mitochondrial dysfunction accounts for the degenerative changes in all phenotypes of PINK1 mutants. Notably, we also found that PINK1 mutants share marked phenotypic similarities with parkin mutants. Transgenic expression of Parkin markedly ameliorated all PINK1 loss-of-function phenotypes, but not vice versa, suggesting that Parkin functions downstream of PINK1. Taken together, our genetic evidence clearly establishes that Parkin and PINK1 act in a common pathway in maintaining mitochondrial integrity and function in both muscles and dopaminergic neurons.