11 research outputs found
Automatic threshold determination for a local approach of change detection in long-term signal recordings
CUSUM (cumulative sum) is a well-known method that can be used to detect changes in a signal when the parameters of this signal are known. This paper presents an adaptation of the CUSUM-based change detection algorithms to long-term signal recordings where the various hypotheses contained in the signal are unknown. The starting point of the work was the dynamic cumulative sum (DCS) algorithm, previously developed for application to long-term electromyography (EMG) recordings. DCS has been improved in two ways. The first was a new procedure to estimate the distribution parameters to ensure the respect of the detectability property. The second was the definition of two separate, automatically determined thresholds. One of them (lower threshold) acted to stop the estimation process, the other one (upper threshold) was applied to the detection function. The automatic determination of the thresholds was based on the Kullback-Leibler distance which gives information about the distance between the detected segments (events). Tests on simulated data demonstrated the efficiency of these improvements of the DCS algorithm
Radio emission of extensive air shower at CODALEMA: Polarization of the radio emission along the v*B vector
Cosmic rays extensive air showers (EAS) are associated with transient radio
emission, which could provide an efficient new detection method of high energy
cosmic rays, combining a calorimetric measurement with a high duty cycle. The
CODALEMA experiment, installed at the Radio Observatory in Nancay, France, is
investigating this phenomenon in the 10^17 eV region. One challenging point is
the understanding of the radio emission mechanism. A first observation
indicating a linear relation between the electric field produced and the cross
product of the shower axis with the geomagnetic field direction has been
presented (B. Revenu, this conference). We will present here other strong
evidences for this linear relationship, and some hints on its physical origin.Comment: Contribution to the 31st International Cosmic Ray Conference, Lodz,
Poland, July 2009. 4 pages, 8 figures. v2: Typo fixed, arxiv references adde
Interventional neurorehabilitation for promoting functional recovery post-craniotomy: a proof-of-concept.
Funder: Alan Turing Institute; doi: http://dx.doi.org/10.13039/100012338Funder: Guarantors of Brain; doi: http://dx.doi.org/10.13039/501100000627The human brain is a highly plastic 'complex' network-it is highly resilient to damage and capable of self-reorganisation after a large perturbation. Clinically, neurological deficits secondary to iatrogenic injury have very few active treatments. New imaging and stimulation technologies, though, offer promising therapeutic avenues to accelerate post-operative recovery trajectories. In this study, we sought to establish the safety profile for 'interventional neurorehabilitation': connectome-based therapeutic brain stimulation to drive cortical reorganisation and promote functional recovery post-craniotomy. In n = 34 glioma patients who experienced post-operative motor or language deficits, we used connectomics to construct single-subject cortical networks. Based on their clinical and connectivity deficit, patients underwent network-specific transcranial magnetic stimulation (TMS) sessions daily over five consecutive days. Patients were then assessed for TMS-related side effects and improvements. 31/34 (91%) patients were successfully recruited and enrolled for TMS treatment within two weeks of glioma surgery. No seizures or serious complications occurred during TMS rehabilitation and 1-week post-stimulation. Transient headaches were reported in 4/31 patients but improved after a single session. No neurological worsening was observed while a clinically and statistically significant benefit was noted in 28/31 patients post-TMS. We present two clinical vignettes and a video demonstration of interventional neurorehabilitation. For the first time, we demonstrate the safety profile and ability to recruit, enroll, and complete TMS acutely post-craniotomy in a high seizure risk population. Given the lack of randomisation and controls in this study, prospective randomised sham-controlled stimulation trials are now warranted to establish the efficacy of interventional neurorehabilitation following craniotomy
Geomagnetic origin of the radio emission from cosmic ray induced air showers observed by CODALEMA
The new setup of the CODALEMA experiment installed at the Radio Observatory
in Nancay, France, is described. It includes broadband active dipole antennas
and an extended and upgraded particle detector array. The latter gives access
to the air shower energy, allowing us to compute the efficiency of the radio
array as a function of energy. We also observe a large asymmetry in counting
rates between showers coming from the North and the South in spite of the
symmetry of the detector. The observed asymmetry can be interpreted as a
signature of the geomagnetic origin of the air shower radio emission. A simple
linear dependence of the electric field with respect to vxB is used which
reproduces the angular dependencies of the number of radio events and their
electric polarity.Comment: 9 pages, 15 figures, 1 tabl
Selective elimination of long INterspersed element-1 expressing tumour cells by targeted expression of the HSV-TK suicide gene.
In gene therapy, effective and selective suicide gene expression is crucial. We exploited the endogenous Long INterspersed Element-1 (L1) machinery often reactivated in human cancers to integrate the Herpes Simplex Virus Thymidine Kinase (HSV-TK) suicide gene selectively into the genome of cancer cells. We developed a plasmid-based system directing HSV-TK expression only when reverse transcribed and integrated in the host genome via the endogenous L1 ORF1/2 proteins and an Alu element. Delivery of these new constructs into cells followed by Ganciclovir (GCV) treatment selectively induced mortality of L1 ORF1/2 protein expressing cancer cells, but had no effect on primary cells that do not express L1 ORF1/2. This novel strategy for selective targeting of tumour cells provides high tolerability as the HSV-TK gene cannot be expressed without reverse transcription and integration, and high selectivity as these processes take place only in cancer cells expressing high levels of functional L1 ORF1/2
Radio emission of extensive air shower at CODALEMA: Polarization of the radio emission along the v*B vector
International audienc
Time–frequency and wavelet-based study of an old steel truss bridge before and after retrofitting
Radio emission of extensive air shower at CODALEMA: Polarization of the radio emission along the v*B vector
International audienc
Radio emission of extensive air shower at CODALEMA: Polarization of the radio emission along the v*B vector
International audienc