61 research outputs found
Estimating group size from acoustic footprint to improve Blainville’s beaked whale abundance estimation
The numbers of animals in groups and the density of Blainville’s beaked whale Mesoplodon densirostris (Md) were estimated using passive acoustic data collected on the Atlantic Undersea Test and Evaluation Center (AUTEC). Md typically associate in groups, producing ultrasonic echolocation signals when foraging, and are routinely detected year-round on the AUTEC range. AUTEC includes a large network of hydrophones cabled to shore that can be used to detect Md echolocation signals. Using a first data set, with known group sizes, we used generalized linear models (GLMs) to model group size as a function of the acoustic footprint of a detected deep dive as perceived on the AUTEC hydrophones. The most important variable to explain group size was the detected click rate (total number of clicks detected divided by total length of vocal period duration). Using a second data set, covering 3 separate time periods in 2011 with automated group dive detections, we estimated beaked whale density using a dive counting approach. False positives were removed through manual inspection, removing dives with biologically infeasible characteristics. This led to a total of 8271 detections of beaked whale deep dives, with the average number per day in the three time periods considered being 75, 80 and 76 respectively. Using selected GLM, the mean estimated group size was 2.36 (95% CI 2.15-2.60), 2.30 (95% CI 2.08-2.56), and 2.33 (95% CI 2.19-2.58) whales/group for the 1st, 2nd and 3rd time period. Md density was estimated at 15.8 (95% CI 13.6-21.9), 16.5 (95% CI 13.8-22.4), and 15.8 (95% CI 13.2-21.2) whales/1000km2, respectively. These results support findings from previous studies, and will allow a more precise estimation of group sizes and densities for Md in future research.PostprintPeer reviewe
Insights into Blainville's beaked whale (Mesoplodon densirostris) echolocation ontogeny from recordings of mother-calf pairs
The data we report were collected during two studies, “Behavioral Response Study-2008” and “Using Satellite Telemetry to Monitor Beaked whale Movements on a Navy Range,” both funded by the U.S. Office of Naval Research (ONR). CD received funds for analysis from ONR as part of the “Population Consequences of Acoustic Disturbance” project. LR and PT were supported by the Marine Alliance for Science and Technology for Scotland (MASTS) pooling initiative and their support is gratefully acknowledged. MASTS is funded by the Scottish Funding Council (grant reference HR09011) and contributing institutions.PostprintPeer reviewe
Behavioral responses of satellite tracked Blainville's beaked whales (Mesoplodon densirostris) to mid-frequency active sonar
Funding support for tagging was provided by the US Navy's Office of Naval Research and Living Marine Resources program, the Chief of Naval Operations' Energy and Environmental Readiness Division and the NOAA Fisheries Ocean Acoustics Program. Trevor Joyce was supported by a National Research Council postdoctoral research associateship, hosted by NOAA's Southwest Fisheries Science Center.The vulnerability of beaked whales (Family: Ziphiidae) to intense sound exposure has led to interest in their behavioral responses to mid‐frequency active sonar (MFAS, 3–8 kHz). Here we present satellite‐transmitting tag movement and dive behavior records from Blainville's beaked whales (Mesoplodon densirostris) tagged in advance of naval sonar exercises at the Atlantic Undersea Test and Evaluation Center (AUTEC) in the Bahamas. This represents one of the largest samples of beaked whales individually tracked during sonar operations (n = 7). The majority of individuals (five of seven) were displaced 28–68 km after the onset of sonar exposure and returned to the AUTEC range 2–4 days after exercises ended. Modeled sound pressure received levels were available during the tracking of four individuals and three of those individuals showed declines from initial maxima of 145–172 dB re 1 μPa to maxima of 70–150 dB re 1 μPa following displacements. Dive behavior data from tags showed a continuation of deep diving activity consistent with foraging during MFAS exposure periods, but also suggested reductions in time spent on deep dives during initial exposure periods. These data provide new insights into behavioral responses to MFAS and have important implications for modeling the population consequences of disturbance.Publisher PDFPeer reviewe
On the critical nature of plastic flow: one and two dimensional models
Steady state plastic flows have been compared to developed turbulence because
the two phenomena share the inherent complexity of particle trajectories, the
scale free spatial patterns and the power law statistics of fluctuations. The
origin of the apparently chaotic and at the same time highly correlated
microscopic response in plasticity remains hidden behind conventional
engineering models which are based on smooth fitting functions. To regain
access to fluctuations, we study in this paper a minimal mesoscopic model whose
goal is to elucidate the origin of scale free behavior in plasticity. We limit
our description to fcc type crystals and leave out both temperature and rate
effects. We provide simple illustrations of the fact that complexity in rate
independent athermal plastic flows is due to marginal stability of the
underlying elastic system. Our conclusions are based on a reduction of an
over-damped visco-elasticity problem for a system with a rugged elastic energy
landscape to an integer valued automaton. We start with an overdamped one
dimensional model and show that it reproduces the main macroscopic
phenomenology of rate independent plastic behavior but falls short of
generating self similar structure of fluctuations. We then provide evidence
that a two dimensional model is already adequate for describing power law
statistics of avalanches and fractal character of dislocation patterning. In
addition to capturing experimentally measured critical exponents, the proposed
minimal model shows finite size scaling collapse and generates realistic shape
functions in the scaling laws.Comment: 72 pages, 40 Figures, International Journal of Engineering Science
for the special issue in honor of Victor Berdichevsky, 201
p63 is an alternative p53 repressor in melanoma that confers chemoresistance and a poor prognosis.
The role of apoptosis in melanoma pathogenesis and chemoresistance is poorly characterized. Mutations in TP53 occur infrequently, yet the TP53 apoptotic pathway is often abrogated. This may result from alterations in TP53 family members, including the TP53 homologue TP63. Here we demonstrate that TP63 has an antiapoptotic role in melanoma and is responsible for mediating chemoresistance. Although p63 was not expressed in primary melanocytes, up-regulation of p63 mRNA and protein was observed in melanoma cell lines and clinical samples, providing the first evidence of significant p63 expression in this lineage. Upon genotoxic stress, endogenous p63 isoforms were stabilized in both nuclear and mitochondrial subcellular compartments. Our data provide evidence of a physiological interaction between p63 with p53 whereby translocation of p63 to the mitochondria occurred through a codependent process with p53, whereas accumulation of p53 in the nucleus was prevented by p63. Using RNA interference technology, both isoforms of p63 (TA and ΔNp63) were demonstrated to confer chemoresistance, revealing a novel oncogenic role for p63 in melanoma cells. Furthermore, expression of p63 in both primary and metastatic melanoma clinical samples significantly correlated with melanoma-specific deaths in these patients. Ultimately, these observations provide a possible explanation for abrogation of the p53-mediated apoptotic pathway in melanoma, implicating novel approaches aimed at sensitizing melanoma to therapeutic agents
SLY regulates genes involved in chromatin remodeling and interacts with TBL1XR1 during sperm differentiation
Sperm differentiation requires unique transcriptional regulation and chromatin remodeling after meiosis to ensure proper compaction and protection of the paternal genome. Abnormal sperm chromatin remodeling can induce sperm DNA damage, embryo lethality and male infertility, yet, little is known about the factors which regulate this process. Deficiency in Sly, a mouse Y chromosome-encoded gene expressed only in postmeiotic male germ cells, has been shown to result in the deregulation of hundreds of sex chromosome-encoded genes associated with multiple sperm differentiation defects and subsequent male infertility. The underlying mechanism remained, to date, unknown. Here, we show that SLY binds to the promoter of sex chromosome-encoded and autosomal genes highly expressed postmeiotically and involved in chromatin regulation. Specifically, we demonstrate that Sly knockdown directly induces the deregulation of sex chromosome-encoded H2A variants and of the H3K79 methyltransferase DOT1L. The modifications prompted by loss of Sly alter the postmeiotic chromatin structure and ultimately result in abnormal sperm chromatin remodeling with negative consequences on the sperm genome integrity. Altogether our results show that SLY is a regulator of sperm chromatin remodeling. Finally we identified that SMRT/N-CoR repressor complex is involved in gene regulation during sperm differentiation since members of this complex, in particular TBL1XR1, interact with SLY in postmeiotic male germ cells.This work was supported by Inserm
(Institut National de la Sante et de la Recherche Medicale), the Agence Nationale de
la Recherche program ANR-12–JSV2-0005–01 (to JC), Labex ‘Who am I?’(ANR-11-
LABX-0071 under program ANR-11-IDEX-0005-01) and a Marie Curie fellowship
FP7-PEOPLE-2010-IEF-273143 (to JC
Women In the Cut
Through a comparison between Daphne du Maurier's 1938 novel Rebecca and Susanna Moore's 1995 novel In the Cut, this article considers the extent to which Franco Moretti's theory of the inevitable dissolution of literary genres is true, with specific regard to the genre of the gothic romance. In evaluating both novels' treatment of female subjectivity, unregimented masculinity and the symbiotic relationship between sexual pleasure and mortal danger, this article investigates the degree to which a contemporary novel such as In the Cut, which is generally acknowledged to be an ‘erotic thriller’, is heavily indebted to the gothic romance and may therefore be interpreted as a continuation of this more traditional genre, and, conversely, the means through which Moore's novel exhibits an overt and defiant resistance to the gothic romance, thereby signifying the dissolution of this particular genre within twentieth-century women's writing
Human aquaporins: regulators of transcellular water flow
Background: Emerging evidence supports the view that (AQP) aquaporin water channels are regulators of transcellular
water flow. Consistentwith their expression in most tissues, AQPs are associatedwith diverse physiological
and pathophysiological processes.
Scope of review: AQP knockout studies suggest that the regulatory role of AQPs, rather than their action as passive
channels, is their critical function. Transport through all AQPs occurs by a common passive mechanism, but their
regulation and cellular distribution varies significantly depending on cell and tissue type; the role of AQPs in cell
volumeregulation (CVR) is particularly notable. This reviewexamines the regulatory role of AQPs in transcellular
water flow, especially in CVR.We focus on key systems of the human body, encompassing processes as diverse as
urine concentration in the kidney to clearance of brain oedema.
Major conclusions: AQPs are crucial for the regulation of water homeostasis, providing selective pores for the
rapidmovement ofwater across diverse cellmembranes and playing regulatory roles in CVR. Gatingmechanisms
have been proposed for human AQPs, but have only been reported for plant andmicrobial AQPs. Consequently, it
is likely that the distribution and abundance of AQPs in a particular membrane is the determinant of membrane
water permeability and a regulator of transcellular water flow.
General significance: Elucidating the mechanisms that regulate transcellular water flow will improve our understanding
of the human body in health and disease. The central role of specific AQPs in regulating water homeostasis
will provide routes to a range of novel therapies. This article is part of a Special Issue entitled Aquaporins
First Direct Observation of Collider Neutrinos with FASER at the LHC
We report the first direct observation of neutrino interactions at a particle
collider experiment. Neutrino candidate events are identified in a 13.6 TeV
center-of-mass energy collision data set of 35.4 fb using the
active electronic components of the FASER detector at the Large Hadron
Collider. The candidates are required to have a track propagating through the
entire length of the FASER detector and be consistent with a muon neutrino
charged-current interaction. We infer neutrino interactions
with a significance of 16 standard deviations above the background-only
hypothesis. These events are consistent with the characteristics expected from
neutrino interactions in terms of secondary particle production and spatial
distribution, and they imply the observation of both neutrinos and
anti-neutrinos with an incident neutrino energy of significantly above 200 GeV.Comment: Submitted to PRL on March 24 202
Expression and epigenomic landscape of the sex chromosomes in mouse post-meiotic male germ cells
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