840 research outputs found
Pitch-scaled estimation of simultaneous voiced and turbulence-noise components in speech
Almost all speech contains simultaneous contributions from more than one acoustic source within the speaker's vocal tract. In this paper, we propose a method -- the pitch-scaled harmonic filter (PSHF) -- which aims to separate the voiced and turbulence-noise components of the speech signal during phonation, based on a maximum-likelihood approach. The PSHF outputs periodic and aperiodic components that are estimates of the respective contributions of the different types of acoustic source. It produces four reconstructed time series signals by decomposing the original speech signal, first, according to amplitude, and then according to power of the Fourier coefficients. Thus, one pair of periodic and aperiodic signals is optimized for subsequent time-series analysis, and another pair for spectral analysis. The performance of the PSHF algorithm was tested on synthetic signals, using three forms of disturbance (jitter, shimmer and additive noise), and the results were used to predict the performance on real speech. Processing recorded speech examples elicited latent features from the signals, demonstrating the PSHF's potential for analysis of mixed-source speech
Distributions of young cephalopods in the tropical waters of Western Australia over two consecutive summers
Cephalopod paralarvae and juveniles were sampled with light traps deployed at the surface and deeper in the southern NW Shelf and on Ningaloo Reef off Western Australia during two consecutive summers. One cross shelf transect (Exmouth) was sampled in the late spring and summers of 1997/1998 (summer 1) and 1998/1999 (summer 2), and a second cross shelf transect (Thevenard) and a longshore transect (Ningaloo) along the Ningaloo Reef were sampled in summer 2. Species captured in the order of abundance were octopods, Photololigo sp., Sepioteuthis lessoniana, and Sthenoteuthis oualaniensis. Most were captured in shallow traps except for Photololigo sp., which was common in both shallow and deep traps with larger animals found in deeper water. The presence of Idiosepius pygmaeus in deep water off Ningaloo Reef revealed the species to be eurytopic, inhabiting a wider range of habitats than previously known. Photololigo sp. and S. lessoniana were more abundant inshore, and octopods were especially abundant on mid-depth stations of the Exmouth transect, probably because of the turbulent mixing and increased productivity there. Fewer S. oualaniensis were caught during the first summer on the Ningaloo transect (n = 5) than during the second summer (n = 79)
Molecular Insights into Division of Single Human Cancer Cells in On-Chip Transparent Microtubes.
In vivo, mammalian cells proliferate within 3D environments consisting of numerous microcavities and channels, which contain a variety of chemical and physical cues. External environments often differ between normal and pathological states, such as the unique spatial constraints that metastasizing cancer cells experience as they circulate the vasculature through arterioles and narrow capillaries, where they can divide and acquire elongated cylindrical shapes. While metastatic tumors cause most cancer deaths, factors impacting early cancer cell proliferation inside the vasculature and those that can promote the formation of secondary tumors remain largely unknown. Prior studies investigating confined mitosis have mainly used 2D cell culture systems. Here, we mimic aspects of metastasizing tumor cells dividing inside blood capillaries by investigating single-cell divisions of living human cancer cells, trapped inside 3D rolled-up, transparent nanomembranes. We assess the molecular effects of tubular confinement on key mitotic features, using optical high- and super-resolution microscopy. Our experiments show that tubular confinement affects the morphology and dynamics of the mitotic spindle, chromosome arrangements, and the organization of the cell cortex. Moreover, we reveal that membrane blebbing and/or associated processes act as a potential genome-safety mechanism, limiting the extent of genomic instability caused by mitosis in confined circumstances, especially in tubular 3D microenvironments. Collectively, our study demonstrates the potential of rolled-up nanomembranes for gaining molecular insights into key cellular events occurring in tubular 3D microenvironments in vivo.The research leading to these results has received funding from the European Research Council under the European Unionâs Seventh Framework Programme (FP7/2007-2013)/ERC grant agreement no. 311529 (S.S.) and the Volkswagen Foundation no. 86 362 (S.S. and W.X.), a FEBS Return-to-Europe fellowship (C.K.S.), the Wellcome Trust (092096/Z/10/Z for N.L.; 094587/Z/10/Z for R.B.), and a European Research Council (ERC) Starting Researcher Grant (R.E.C.-S.; SYSGRO). O.G.S. acknowledges financial support from the DFG Research Unit 1713 âSensorische Mikro und Nanosystemeâ. D.H.G. acknowledges funding from the Alexander von Humboldt Foundation and the U.S. National Science Foundation (Grants: CMMI 1200241 and CBET-1442014). Research in the S.P.J. laboratory is funded by Cancer Research U.K., the ERC, and the European Community Seventh Framework Programme (DDResponse), with core infrastructure provided by Cancer Research U.K. and the Wellcome Trust.This is the final version of the article. It first appeared from the American Chemical Society via http://dx.doi.org/10.1021/acsnano.6b0046
Elevated Atmospheric Carbon Dioxide Concentrations Amplify Alternaria alternata Sporulation and Total Antigen Production
Background
Although the effect of elevated carbon dioxide (CO2) concentration on pollen production has been established in some plant species, impacts on fungal sporulation and antigen production have not been elucidated.
Objective
Our purpose was to examine the effects of rising atmospheric CO2 concentrations on the quantity and quality of fungal spores produced on timothy (Phleum pratense) leaves.
Methods
Timothy plants were grown at four CO2 concentrations (300, 400, 500, and 600 ÎŒmol/mol). Leaves were used as growth substrate for Alternaria alternata and Cladosporium phlei. The spore abundance produced by both fungi, as well as the size (microscopy) and antigenic protein content (ELISA) of A. alternata, were quantified.
Results
Leaf carbon-to-nitrogen ratio was greater at 500 and 600 ÎŒmol/mol, and leaf biomass was greater at 600 ÎŒmol/mol than at the lower CO2 concentrations. Leaf carbon-to-nitrogen ratio was positively correlated with A. alternata spore production per gram of leaf but negatively correlated with antigenic protein content per spore. At 500 and 600 ÎŒmol/mol CO2 concentrations, A. alternata produced nearly three times the number of spores and more than twice the total antigenic protein per plant than at lower concentrations. C. phlei spore production was positively correlated with leaf carbon-to-nitrogen ratio, but overall spore production was much lower than in A. alternata, and total per-plant production did not vary among CO2 concentrations.
Conclusions
Elevated CO2 concentrations often increase plant leaf biomass and carbon-to-nitrogen ratio. Here we demonstrate for the first time that these leaf changes are associated with increased spore production by A. alternata, a ubiquitous allergenic fungus. This response may contribute to the increasing prevalence of allergies and asthma
Ringed, Bearded, and Ribbon Seal Vocalizations North of Barrow, Alaska: Seasonal Presence and Relationship with Sea Ice
The acoustic repertoires of ringed, bearded, and ribbon seals are described, along with their seasonal occurrence and relationship to sea ice concentration. Acoustic recordings were made between September and June over three years (2006 â 09) along the continental slope break in the Chukchi Sea, 120 km north-northwest of Barrow, Alaska. Vocalizations of ringed and bearded seals occurred in winter and during periods of 80% â 100% ice cover but were mostly absent during open water periods. The presence of ringed and bearded seal calls throughout winter and spring suggests that some portion of their population is overwintering. Analysis of the repertoire of ringed and bearded seal calls shows seasonal variation. Ringed seal calls are primarily barks in winter and yelps in spring, while bearded seal moans increase during spring. Ribbon seal calls were detected only in the fall of 2008 during the open water period. The repertoire of known ribbon seal vocalizations was expanded to include three additional calls, and two stereotyped call sequences were common. Retrospective analyses of ringed seal recordings from 1982 and ribbon seal recordings from 1967 showed a high degree of stability in call repertoire across large spatial and temporal scales.Le rĂ©pertoire acoustique des phoques annelĂ©s, des phoques barbus et des phoques Ă bandes sont dĂ©crits, de mĂȘme que leur prĂ©sence saisonniĂšre et leur rapport avec la concentration de glace de mer. Des enregistrements acoustiques ont Ă©tĂ© effectuĂ©s entre septembre et juin sur une pĂ©riode de trois ans (2006 â 2009), le long de la rupture de la pente continentale, dans la mer des Tchouktches, Ă 120 km au nord-nord-ouest de Barrow, en Alaska. Les vocalisations de phoques annelĂ©s et de phoques barbus Ă©taient prĂ©sentes pendant lâhiver et pendant les pĂ©riodes oĂč la concentration de glace Ă©tait de 80 % Ă 100 %, mais elles se faisaient rares pendant les pĂ©riodes dâeau libre. La prĂ©sence des cris de phoques annelĂ©s et de phoques barbus tout au long de lâhiver et du printemps suggĂšre quâune partie de leur population hiverne. Lâanalyse du rĂ©pertoire de cris de phoques annelĂ©s et de phoques barbus indique une variation saisonniĂšre. Lâhiver, le cri du phoque annelĂ© prend principalement la forme dâaboiements, tandis que le printemps, il prend la forme de glapissements. Les gĂ©missements du phoque barbu sâintensifient au printemps. Le cri des phoques Ă bandes nâa Ă©tĂ© captĂ© quâĂ lâautomne 2008, pendant la pĂ©riode des eaux libres. Le rĂ©pertoire des vocalisations connues du phoque Ă bandes a Ă©tĂ© Ă©largi pour inclure trois autres cris, bien que deux sĂ©quences de cris stĂ©rĂ©otypĂ©es Ă©taient courantes. Lâanalyse rĂ©trospective des enregistrements de cris de phoques annelĂ©s de 1982 et de phoques Ă bandes de 1967 a laissĂ© entrevoir une grande stabilitĂ© du point de vue du rĂ©pertoire des cris, et ce, sur de vastes Ă©chelles spatiales et temporelles
Developing an intervention to facilitate family communication about inherited genetic conditions, and training genetic counsellors in its delivery.
Many families experience difficulty in talking about an inherited genetic condition that affects one or more of them. There have now been a number of studies identifying the issues in detail, however few have developed interventions to assist families. The SPRinG collaborative have used the UK Medical Research Council's guidance on Developing and Evaluating Complex Interventions, to work with families and genetic counsellors (GCs) to co-design a psycho-educational intervention to facilitate family communication and promote better coping and adaptation to living with an inherited genetic condition for parents and their children (<18 years). The intervention is modelled on multi-family discussion groups (MFDGs) used in psychiatric settings. The MFDG was developed and tested over three phases. First focus groups with parents, young people, children and health professionals discussed whether MFDG was acceptable and proposed a suitable design. Using evidence and focus group data, the intervention and a training manual were developed and three GCs were trained in its delivery. Finally, a prototype MFDG was led by a family therapist and co-facilitated by the three GCs. Data analysis showed that families attending the focus groups and intervention thought MFDG highly beneficial, and the pilot sessions had a significant impact on their family' functioning. We also demonstrated that it is possible to train GCs to deliver the MFDG intervention. Further studies are now required to test the feasibility of undertaking a definitive randomised controlled trial to evaluate its effectiveness in improving family outcomes before implementing into genetic counselling practice.The National Institute of Health Research funded the study but any views expressed do not necessarily reflect those of the Authority. Funded by NIHR reference number: RP-DG-1211-10015
Debris Disks: Probing Planet Formation
Debris disks are the dust disks found around ~20% of nearby main sequence
stars in far-IR surveys. They can be considered as descendants of
protoplanetary disks or components of planetary systems, providing valuable
information on circumstellar disk evolution and the outcome of planet
formation. The debris disk population can be explained by the steady
collisional erosion of planetesimal belts; population models constrain where
(10-100au) and in what quantity (>1Mearth) planetesimals (>10km in size)
typically form in protoplanetary disks. Gas is now seen long into the debris
disk phase. Some of this is secondary implying planetesimals have a Solar
System comet-like composition, but some systems may retain primordial gas.
Ongoing planet formation processes are invoked for some debris disks, such as
the continued growth of dwarf planets in an unstirred disk, or the growth of
terrestrial planets through giant impacts. Planets imprint structure on debris
disks in many ways; images of gaps, clumps, warps, eccentricities and other
disk asymmetries, are readily explained by planets at >>5au. Hot dust in the
region planets are commonly found (<5au) is seen for a growing number of stars.
This dust usually originates in an outer belt (e.g., from exocomets), although
an asteroid belt or recent collision is sometimes inferred.Comment: Invited review, accepted for publication in the 'Handbook of
Exoplanets', eds. H.J. Deeg and J.A. Belmonte, Springer (2018
The Lost Library of Anne Conway
The philosopher Anne Conway (1631-1679) owned a large library, and her reading and book ownership shaped her intellectual life in distinctive ways. Until now, however, almost nothing has been known about the details of her reading or her book collection. Current scholarship assumes that her library, like that of her husband, the third Viscount Conway (c. 1623â1683), was lost or dispersed after her death. This article presents previously unrecognised evidence of Conwayâs book ownership, and identifies, for the first time, the only books currently known to survive from her personal library. It traces their path to their current location in the Old Library of Jesus College, Cambridge, through the library of the soldier, book collector, and Cambridge Fellow Francis Sterling (c. 1652-1692). The article demonstrates that the newly identified books reveal previously unknown patterns of intellectual exchange amongst Conwayâs family, and argues that they have significant implications for our understanding of her early intellectual development
The Milky Way's circular velocity curve between 4 and 14 kpc from APOGEE data
We measure the Milky Way's rotation curve over the Galactocentric range 4 kpc
<~ R <~ 14 kpc from the first year of data from the Apache Point Observatory
Galactic Evolution Experiment (APOGEE). We model the line-of-sight velocities
of 3,365 stars in fourteen fields with b = 0 deg between 30 deg < l < 210 deg
out to distances of 10 kpc using an axisymmetric kinematical model that
includes a correction for the asymmetric drift of the warm tracer population
(\sigma_R ~ 35 km/s). We determine the local value of the circular velocity to
be V_c(R_0) = 218 +/- 6 km/s and find that the rotation curve is approximately
flat with a local derivative between -3.0 km/s/kpc and 0.4 km/s/kpc. We also
measure the Sun's position and velocity in the Galactocentric rest frame,
finding the distance to the Galactic center to be 8 kpc < R_0 < 9 kpc, radial
velocity V_{R,sun} = -10 +/- 1 km/s, and rotational velocity V_{\phi,sun} =
242^{+10}_{-3} km/s, in good agreement with local measurements of the Sun's
radial velocity and with the observed proper motion of Sgr A*. We investigate
various systematic uncertainties and find that these are limited to offsets at
the percent level, ~2 km/s in V_c. Marginalizing over all the systematics that
we consider, we find that V_c(R_0) 99% confidence. We find an
offset between the Sun's rotational velocity and the local circular velocity of
26 +/- 3 km/s, which is larger than the locally-measured solar motion of 12
km/s. This larger offset reconciles our value for V_c with recent claims that
V_c >~ 240 km/s. Combining our results with other data, we find that the Milky
Way's dark-halo mass within the virial radius is ~8x10^{11} M_sun.Comment: submitted to Ap
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