Creating a spontaneous conversational speech corpus

Speech recognition and language analysis of spontaneous speech arising in naturally spoken conversations are becoming the subject of much research. However, there is a shortage of spontaneous speech corpora that are freely available for academics. We therefore undertook the building of a natural conversation speech database, recording over 200 hours of conversations in English by over 600 local university students. With few exceptions, the students used their own cell phones from their own rooms or homes to speak to one another, and they were permitted to speak on any topic they chose. Although they knew that they were being recorded and that they would receive a small payment, their conversations in the corpus are probably very close to being natural and spontaneous. This paper describes a detailed case study of the problems we faced and the methods we used to make the recordings and control the collection of these social science data on a limited budget.

Spontaneous intramedullary apoptosis is present in disorders other than myelodysplasia

Myelodysplastic syndrome (MDS) is a group of hematopoietic disorders characterized by peripheral cytopenias in the presence of normo- or hypercellular dysplastic marrow. It has been suggested that premature intramedullary apoptosis may contribute to this phenomenon. We used terminal dUTP nick-end labeling (TUNEL) of bone marrow biopsy specimens and cytocentrifuge preparations from patients with MDS and a variety of other hematopoietic disorders to determine whether there is increased intramedullary apoptosis in MDS and whether any such effect is specific to MDS. TUNEL labeling of bone marrow from 24 patients with MDS revealed significant positivity in 10 of 11 patients with refractory anemia (RA), five of seven with RA and excess of blasts (RAEB), all three patients with RAEB in transformation (RAEB-t), and all three patients with RA with ring sideroblasts (RARS). The percent of positive cells ranged from 5 to 50% but showed no apparent correlation with morphological subtype. In a series of 29 patients with acute leukemia, 17 showed significant positivity (13 of 13 with myeloid disease: three M1, seven M2, one M3, two M4; four of 16 patients with lymphoid disease: one Burkitt-type lymphoma, two null acute leukemia, and one common acute lymphoid leukemia). Intramedullary apoptosis was associated with myeloid or early committed progenitor cells and was highest in secondary acute myeloid leukemia (AML). Normal bone marrow samples from 12 individuals showed no evidence of apoptosis. Our results suggest that an increased level of intramedullary apoptosis is apparent in both patients with MDS and those with AML; those with secondary AML have the highest levels. The relative absence of such findings in lymphoid malignancy suggests that the apoptotic pathways are different in this lineage.

INFLUENCE OF CORE POLARIZATION ON THE ELECTRON-AFFINITY OF CA

We have developed a method, based on the use of B-spline basis sets and model potentials, for determining properties of systems with two or three electrons outside a polarizable closed-shell core. It is applied to the calculation of the electron affinity of Ca and the resulting value of 17.7 meV is in excellent agreement with the most recent experiments. It is found that the dielectronic core-valence interaction reduces the electron affinity by 39.5 meV.

Spontaneous Attention to Faces in Asperger Sndrome using Ecologically Valid Static Stimuli

Previous eye tracking research on the allocation of attention to social information by individuals with autism spectrum disorders is equivocal and may be in part a consequence of variation in stimuli used between studies. The current study explored attention allocation to faces, and within faces,
by individuals with Asperger syndrome using a range of static stimuli where faces were either viewed in isolation or viewed in the context of a social scene. Results showed that faces were viewed typically by the individuals with Asperger syndrome when presented in isolation, but attention to the eyes was significantly diminished in comparison to age and IQ-matched typical viewers when faces were viewed as part of social scenes. We show that when using static stimuli, there is evidence of atypicality for individuals with Asperger syndrome depending on the extent of social context. Our findings shed light on the previous explanations of gaze behaviour that have emphasised the role of movement in atypicalities of social attention in autism spectrum disorders and highlight the importance of consideration of the realistic portrayal of social information for future studies.

Connective tissue growth factor [CTGF]/CCN2 stimulates mesangial cell migration through integrated dissolution of focal adhesion complexes and activation of cell polarization

Connective tissue growth factor [CTGF]/CCN2 is a prototypic member of the CCN family of regulatory proteins. CTGF expression is up-regulated in a number of fibrotic diseases, including diabetic nephropathy, where it is believed to act as a downstream mediator of TGF-beta function; however, the exact mechanisms whereby CTGF mediates its effects remain unclear. Here, we describe the role of CTGF in cell migration and actin disassembly in human mesangial cells, a primary target in the development of renal glomerulosclerosis. The addition of CTGF to primary mesangial cells induced cell migration and cytoskeletal rearrangement but had no effect on cell proliferation. Cytoskeletal rearrangement was associated with a loss of focal adhesions, involving tyrosine dephosphorylation of focal adhesion kinase and paxillin, increased activity of the protein tyrosine phosphatase SHP-2, with a concomitant decrease in RhoA and Rac1 activity. Conversely, Cdc42 activity was increased by CTGF. These functional responses were associated with the phosphorylation and translocation of protein kinase C-zeta to the leading edge of migrating cells. Inhibition of CTGF-induced protein kinase C-zeta activity with a myristolated PKC-zeta inhibitor prevented cell migration. Moreover, transient transfection of human mesangial cells with a PKC-zeta kinase inactive mutant (dominant negative) expression vector also led to a decrease in CTGF-induced migration compared with wild-type. Furthermore, CTGF stimulated phosphorylation and activation of GSK-3beta. These data highlight for the first time an integrated mechanism whereby CTGF regulates cell migration through facilitative actin cytoskeleton disassembly, which is mediated by dephosphorylation of focal adhesion kinase and paxillin, loss of RhoA activity, activation of Cdc42, and phosphorylation of PKC-zeta and GSK-3beta. These changes indicate that the initial stages of CTGF mediated mesangial cell migration are similar to those involved in the process of cell polarization. These findings begin to shed mechanistic light on the renal diabetic milieu, where increased CTGF expression in the glomerulus contributes to cellular dysfunction.

Contribution of reverse Na+/Ca2+ exchange to spontaneous activity in interstitial cells of cajal in the rabbit urethra

Interstitial cells of Cajal (ICC) isolated from the rabbit urethra exhibit regular Ca2+ oscillations that are associated with spontaneous transient inward currents (STICs) recorded under voltage clamp. Their frequency is known to be very sensitive to external Ca2+ concentration but the mechanism of this has yet to be elucidated. In the present study experiments were performed to assess the role of Na+-Ca2+ exchange (NCX) in this process. Membrane currents were recorded using the patch clamp technique and measurements of intracellular Ca2+ were made using fast confocal microscopy. When reverse mode NCX was enhanced by decreasing the external Na+ concentration [Na+]o from 130 to 13 mM, the frequency of global Ca2+ oscillations and STICs increased. Conversely, inhibition of reverse mode NCX by KB-R7943 and SEA0400 decreased the frequency of Ca2+ oscillations and STICs. Application of caffeine (10 mM) and noradrenaline (10 microM) induced transient Ca2+-activated chloride currents (I(ClCa)) at -60 mV due to release of Ca2+ from ryanodine- and inositol trisphosphate (IP3)-sensitive Ca2+ stores, respectively, but these responses were not blocked by KB-R7943 or SEA0400 suggesting that neither drug blocked Ca2+-activated chloride channels or Ca2+ release from stores. Intact strips of rabbit urethra smooth muscle develop spontaneous myogenic tone. This tone was relaxed by application of SEA0400 in a concentration-dependent fashion. Finally, single cell RT-PCR experiments revealed that isolated ICC from the rabbit urethra only express the type 3 isoform of the Na+-Ca2+ exchanger (NCX3). These results suggest that frequency of spontaneous activity in urethral ICC can be modulated by Ca2+ entry via reverse NCX.

Self-potential and spectral induced polarization signals associated with microbial sulphate reduction

Self-potential and spectral induced polarization responses associated with microbial processes involved in sulphate reduction have been monitored in a Perspex Winogradsky column filled with glass beads and growth medium. Salt-bridge is utilized as an electrolytic contact between experiment and control column. Equally spaced SP electrodes are used in combination of Ag-AgCl electrodes to compare electrodic and SP signals associated with the microbial processes involved in sulphate reduction. This study reveals that magnitude of SP varies from 5 to -2 mV and Electrodic potential 0 to -20 mV at the time of domination (day 39) of sulphate reducing bacteria which are very small in comparison to those measured by fixing both measuring and reference Ag-AgCl electrodes in experiment column. We observed that real and imaginary parts of complex conductivities increase with increase in production of H2S and CO in the experiment column. Both real and imaginary parts of surface complex conductivity vary at low frequencies similar to typical growth curve of bacterial population. Sodium lactate as a carbon source, dissolved in Lagan River water was flushed into the column for biostimulation on 144th day. The dissolved oxygen in flushed fluid might have killed the anaerobes in the column and decrease in complex conductivities similar to death phase of bacteria is observed for one week. The results obtained from this experiment should contribute to further understanding the biogeophysical responses involved in complex environments.


Read More: http://library.seg.org/doi/abs/10.1190/segj092009-001.57

Demographic noise can lead to the spontaneous formation of species

When a collection of phenotypically diverse organisms compete with each other for limited resources, the population can evolve into tightly localised clusters. Past studies have neglected the effects of demographic noise and studied the population on a macroscopic scale, where cluster formation is found to depend on the shape of the curve describing the decline of competition strength with phenotypic distance. Here we show how including the effects of demographic noise leads to a radically different conclusion. Two situations are identified: a weak-noise regime in which the population exhibits patterns of fluctuation around the macroscopic description, and a strong-noise regime where clusters appear spontaneously even in the case that all organisms have equal fitness. editor's choice Copyright (C) EPLA, 2012

STO and GTO field-induced polarization functions for H to Kr

Field-induced polarization (FIP) functions were proposed over two decades ago to improve the accuracy of calculated response properties, and the FIP functions in GTO form for H and C to F were tested on small molecules, with encouraging results. The concept of FIP,is now extended to all atoms up to Kr. New simplifying approximations for the description of asymptotic highest occupied atomic orbitals. (HOAOs) are introduced in this study. They provide the basis for STO and GTO exponents of a complete set of FIP functions from H to Kr, which are both listed for the convenience of the users. Tests on the polarizabilities of a series of atoms and molecules demonstrate that addition of the FIP basis functions to a series' of standard basis sets drastically improves the performance of all these basis sets compared to converged results. Moreover, the byproduct of this study (approximate asymptotic HOAOs) provides information for the construction of accurate basis sets for long-range ground state properties. (C) 2003 Wiley Periodicals, Inc.

Functional expression of KCNQ (Kv7) channels in guinea-pig bladder smooth muscle and their contribution to spontaneous activity

Background and Purpose: The aim of the study was to determine whether KCNQ channels are functionally expressed in bladder smooth muscle cells (SMC) and to investigate their physiological significance in bladder contractility. 

Experimental Approach: KCNQ channels were examined at the genetic, protein, cellular and tissue level in guinea pig bladder smooth muscle using RT-PCR, immunofluorescence, patch-clamp electrophysiology, calcium imaging, detrusor strip myography, and a panel of KCNQ activators and inhibitors. 

Key Results: KCNQ subtypes 1-5 are expressed in bladder detrusor smooth muscle. Detrusor strips typically displayed TTX-insensitive myogenic spontaneous contractions that were increased in amplitude by the KCNQ channel inhibitors XE991, linopirdine or chromanol 293B. Contractility was inhibited by the KCNQ channel activators flupirtine or meclofenamic acid (MFA). The frequency of Ca2+-oscillations in SMC contained within bladder tissue sheets was increased by XE991. Outward currents in dispersed bladder SMC, recorded under conditions where BK and KATP currents were minimal, were significantly reduced by XE991, linopirdine, or chromanol, and enhanced by flupirtine or MFA. XE991 depolarized the cell membrane and could evoke transient depolarizations in quiescent cells. Flupirtine (20M) hyperpolarized the cell membrane with a simultaneous cessation of any spontaneous electrical activity. 

Conclusions and Implications: These novel findings reveal the role of KCNQ currents in the regulation of the resting membrane potential of detrusor SMC and their important physiological function in the control of spontaneous contractility in the guinea pig bladder.