182 research outputs found
Towards Efficient Full Pose Omnidirectionality with Overactuated MAVs
Omnidirectional MAVs are a growing field, with demonstrated advantages for
aerial interaction and uninhibited observation. While systems with complete
pose omnidirectionality and high hover efficiency have been developed
independently, a robust system that combines the two has not been demonstrated
to date. This paper presents VoliroX: a novel omnidirectional vehicle that can
exert a wrench in any orientation while maintaining efficient flight
configurations. The system design is presented, and a 6 DOF geometric control
that is robust to singularities. Flight experiments further demonstrate and
verify its capabilities.Comment: 10 pages, 6 figures, ISER 2018 conference submissio
4D STEM: high efficiency phase contrast imaging using a fast pixelated detector
Phase contrast imaging is widely used for imaging beam sensitive and weak phase objects in electron microscopy. In this work we demonstrate the achievement of high efficient phase contrast imaging in STEM using the pnCCD, a fast direct electron pixelated detector, which records the diffraction patterns at every probe position with a speed of 1000 to 4000 frames per second, forming a 4D STEM dataset simultaneously with the incoherent Z-contrast imaging. Ptychographic phase reconstruction has been applied and the obtained complex transmission function reveals the phase of the specimen. The results using GaN and Ti, Nd- doped BiFeO3 show that this imaging mode is especially powerful for imaging light elements in the presence of much heavier elements
Modeling and control of UAV bearing formations with bilateral high-level steering
In this paper we address the problem of controlling the motion of a group of unmanned aerial vehicles (UAVs) bound to keep a formation defined in terms of only relative angles (i.e. a bearing formation). This problem can naturally arise within the context of several multi-robot applications such as, e.g. exploration, coverage, and surveillance. First, we introduce and thoroughly analyze the concept and properties of bearing formations, and provide a class of minimally linear sets of bearings sufficient to uniquely define such formations. We then propose a bearing-only formation controller requiring only bearing measurements, converging almost globally, and maintaining bounded inter-agent distances despite the lack of direct metric information.The controller still leaves the possibility of imposing group motions tangent to the current bearing formation. These can be either autonomously chosen by the robots because of any additional task (e.g. exploration), or exploited by an assisting human co-operator. For this latter 'human-in-the-loop' case, we propose a multi-master/multi-slave bilateral shared control system providing the co-operator with some suitable force cues informative of the UAV performance. The proposed theoretical framework is extensively validated by means of simulations and experiments with quadrotor UAVs equipped with onboard cameras. Practical limitations, e.g. limited field-of-view, are also considered. © The Author(s) 2012
Mutual induction of magnetic 3d and 4f order in multiferroic hexagonal ErMnO3
The complex interplay between the 3d and 4f moments in hexagonal ErMnO3 is
investigated by magnetization, optical second harmonic generation, and
neutron-diffraction measurements. We revise the phase diagram and provide a
microscopic model for the emergent spin structures with a special focus on the
intermediary phase transitions. Our measurements reveal that the 3d exchange
between Mn^{3+} ions dominates the magnetic symmetry at 10 K < T < T_N with
Mn^3+ order according to the Gamma_4 representation triggering 4f ordering
according to the same representation on the Er^{3+}(4b) site. Below 10 K the
magnetic order is governed by 4f exchange interactions of Er^{3+} ions on the
2a site. The magnetic Er^{3+}(2a) order according to the representation Gamma_2
induces a magnetic reorientation (Gamma_4 --> Gamma_2) at the Er^{3+}(4b) and
the Mn^{3+} sites. Our findings highlight the fundamentally different roles the
Mn^{3+}, R^{3+}(2a), and R^{3+}(4b) magnetism play in establishing the magnetic
phase diagram of the hexagonal RMnO3 system
Phonons in mesoporous silicon The influence of nanostructuring on the dispersion in the Debye regime
We present a comprehensive scattering study of nanostructured silicon. Neutron and x ray scattering experiments elucidate structural and dynamical properties of electrochemically etched, porous silicon membranes with pores roughly 8 nm across. In particular, inelastic cold neutron scattering techniques reveal the phonon dispersion of the nanostructured, single crystalline samples in the linear Debye regime for energy transfers up to 4 meV. A modified dispersion relation characterized by systematically reduced sound velocities manifests itself in altered elastic properties of porous silicon when compared to bulk silicon. Its relevance for nanostructured silicon as thermoelectric material of interest is discusse
Thermodynamic Properties of the Anisotropic Frustrated Spin-chain Compound Linarite PbCuSO(OH)
We present a comprehensive macroscopic thermodynamic study of the
quasi-one-dimensional (1D) frustrated spin-chain system
linarite. Susceptibility, magnetization, specific heat, magnetocaloric effect,
magnetostriction, and thermal-expansion measurements were performed to
characterize the magnetic phase diagram. In particular, for magnetic fields
along the b axis five different magnetic regions have been detected, some of
them exhibiting short-range-order effects. The experimental magnetic entropy
and magnetization are compared to a theoretical modelling of these quantities
using DMRG and TMRG approaches. Within the framework of a purely 1D isotropic
model Hamiltonian, only a qualitative agreement between theory and the
experimental data can be achieved. Instead, it is demonstrated that a
significant symmetric anisotropic exchange of about 10% is necessary to account
for the basic experimental observations, including the 3D saturation field, and
which in turn might stabilize a triatic (three-magnon) multipolar phase.Comment: 20 pages, 17 figure
Search for Gravitational Waves from Low Mass Compact Binary Coalescence in LIGO's Sixth Science Run and Virgo's Science Runs 2 and 3
We report on a search for gravitational waves from coalescing compact
binaries using LIGO and Virgo observations between July 7, 2009 and October 20,
2010. We searched for signals from binaries with total mass between 2 and 25
solar masses; this includes binary neutron stars, binary black holes, and
binaries consisting of a black hole and neutron star. The detectors were
sensitive to systems up to 40 Mpc distant for binary neutron stars, and further
for higher mass systems. No gravitational-wave signals were detected. We report
upper limits on the rate of compact binary coalescence as a function of total
mass, including the results from previous LIGO and Virgo observations. The
cumulative 90%-confidence rate upper limits of the binary coalescence of binary
neutron star, neutron star- black hole and binary black hole systems are 1.3 x
10^{-4}, 3.1 x 10^{-5} and 6.4 x 10^{-6} Mpc^{-3}yr^{-1}, respectively. These
upper limits are up to a factor 1.4 lower than previously derived limits. We
also report on results from a blind injection challenge.Comment: 11 pages, 5 figures. For a repository of data used in the
publication, go to:
. Also see the
announcement for this paper on ligo.org at:
<http://www.ligo.org/science/Publication-S6CBCLowMass/index.php
Implementation and testing of the first prompt search for gravitational wave transients with electromagnetic counterparts
Aims. A transient astrophysical event observed in both gravitational wave
(GW) and electromagnetic (EM) channels would yield rich scientific rewards. A
first program initiating EM follow-ups to possible transient GW events has been
developed and exercised by the LIGO and Virgo community in association with
several partners. In this paper, we describe and evaluate the methods used to
promptly identify and localize GW event candidates and to request images of
targeted sky locations.
Methods. During two observing periods (Dec 17 2009 to Jan 8 2010 and Sep 2 to
Oct 20 2010), a low-latency analysis pipeline was used to identify GW event
candidates and to reconstruct maps of possible sky locations. A catalog of
nearby galaxies and Milky Way globular clusters was used to select the most
promising sky positions to be imaged, and this directional information was
delivered to EM observatories with time lags of about thirty minutes. A Monte
Carlo simulation has been used to evaluate the low-latency GW pipeline's
ability to reconstruct source positions correctly.
Results. For signals near the detection threshold, our low-latency algorithms
often localized simulated GW burst signals to tens of square degrees, while
neutron star/neutron star inspirals and neutron star/black hole inspirals were
localized to a few hundred square degrees. Localization precision improves for
moderately stronger signals. The correct sky location of signals well above
threshold and originating from nearby galaxies may be observed with ~50% or
better probability with a few pointings of wide-field telescopes.Comment: 17 pages. This version (v2) includes two tables and 1 section not
included in v1. Accepted for publication in Astronomy & Astrophysic
The Porto European Cancer Research Summit 2021
Key stakeholders from the cancer research continuum met in May 2021 at the European Cancer Research Summit in Porto to discuss priorities and specific action points required for the successful implementation of the European Cancer Mission and Europe's Beating Cancer Plan (EBCP). Speakers presented a unified view about the need to establish high-quality, networked infrastructures to decrease cancer incidence, increase the cure rate, improve patient's survival and quality of life, and deal with research and care inequalities across the European Union (EU). These infrastructures, featuring Comprehensive Cancer Centres (CCCs) as key components, will integrate care, prevention and research across the entire cancer continuum to support the development of personalized/precision cancer medicine in Europe. The three pillars of the recommended European infrastructures â namely translational research, clinical/prevention trials and outcomes research â were pondered at length. Speakers addressing the future needs of translational research focused on the prospects of multiomics assisted preclinical research, progress in Molecular and Digital Pathology, immunotherapy, liquid biopsy and science data. The clinical/prevention trial session presented the requirements for next-generation, multicentric trials entailing unified strategies for patient stratification, imaging, and biospecimen acquisition and storage. The third session highlighted the need for establishing outcomes research infrastructures to cover primary prevention, early detection, clinical effectiveness of innovations, health-related quality-of-life assessment, survivorship research and health economics. An important outcome of the Summit was the presentation of the Porto Declaration, which called for a collective and committed action throughout Europe to develop the cancer research infrastructures indispensable for fostering innovation and decreasing inequalities within and between member states. Moreover, the Summit guidelines will assist decision making in the context of a unique EU-wide cancer initiative that, if expertly implemented, will decrease the cancer death toll and improve the quality of life of those confronted with cancer, and this is carried out at an affordable cost.Where authors are identified as personnel of the International Agency for Research on Cancer/World Health Organization, the authors alone are responsible for the views expressed in this article and they do not necessarily represent the decisions, policy or views of the International Agency for Research on Cancer/World Health Organization. JT reports personal financial interest in form of scientific consultancy role for Array Biopharma, AstraZeneca, Avvinity, Bayer, Boehringer Ingelheim, Chugai, DaiichiSankyo, F. HoffmannâLa Roche Ltd, Genentech Inc, HalioDX SAS, Hutchison MediPharma International, Ikena Oncology, IQVIA, Lilly, Menarini, Merck Serono, Merus, MSD, Mirati, Neophore, Novartis, Orion Biotechnology, Peptomyc, Pfizer, Pierre Fabre, Samsung Bioepis, Sanofi, Seattle Genetics, Servier, Taiho, Tessa Therapeutics and TheraMyc. And also educational collaboration with Imedex, Medscape Education, MJH Life Sciences, PeerView Institute for Medical Education and Physicians Education Resource (PER). JT also declares institutional financial interest in form of financial support for clinical trials or contracted research for Amgen Inc, Array Biopharma Inc, AstraZeneca Pharmaceuticals LP, BeiGene, Boehringer Ingelheim, Bristol Myers Squibb, Celgene, Debiopharm International SA, F. HoffmannâLa Roche Ltd, Genentech Inc, HalioDX SAS, Hutchison MediPharma International, JanssenâCilag SA, MedImmune, Menarini, Merck Health KGAA, Merck Sharp & Dohme, Merus NV, Mirati, Novartis FarmacĂ©utica SA, Pfizer, Pharma Mar, Sanofi Aventis Recherche & DĂ©veloppement, Servier, Taiho Pharma USA Inc, Spanish Association Against Cancer Scientific Foundation and Cancer Research UK. MB has received funding for his research projects and for educational grants to the University of Dresden by Bayer AG (2016â2018), Merck KGaA (2014âopen) and Medipan GmbH (2014â2018). He is on the supervisory board of HIâSTEM GmbH (Heidelberg) for the German Cancer Research Center (DKFZ, Heidelberg) and also member of the supervisory body of the CharitĂ© University Hospital, Berlin. As former chair of OncoRay (Dresden) and present CEO and Scientific Chair of the German Cancer Research Center (DKFZ, Heidelberg), he has been or is responsible for collaborations with a multitude of companies and institutions, worldwide. In this capacity, he has discussed potential projects and signed contracts for research funding and/or collaborations with industry and academia for his institute(s) and staff, including but not limited to pharmaceutical companies such as Bayer, Boehringer Ingelheim, Bosch, Roche and other companies such as Siemens, IBA, Varian, Elekta, Bruker, etc. In this role, he was/is also responsible for the commercial technology transfer activities of his institute(s), including the creation of startâups and licensing. This includes the DKFZâPSMA617 related patent portfolio [WO2015055318 (A1), ANTIGEN (PSMA)] and similar IP portfolios. MB confirms that, to the best of his knowledge, none of the above funding sources were involved in the preparation of this paper. BB has received research funding from 4D Pharma, Abbvie, Amgen, Aptitude Health, AstraZeneca, BeiGene, Blueprint Medicines, BMS, Boehringer Ingelheim, Celgene, Cergentis, Cristal Therapeutics, DaiichiâSankyo, Eli Lilly, GSK, Inivata, Janssen, Onxeo, OSE immunotherapeutics, Pfizer, RocheâGenentech, Sanofi, Takeda, Tolero Pharmaceuticals. FC declares consultancy role for: Amgen, Astellas/Medivation, AstraZeneca, Celgene, DaiichiâSankyo, Eisai, GE Oncology, Genentech, GlaxoSmithKline, Macrogenics, Medscape, MerckâSharp, Merus BV, Mylan, Mundipharma, Novartis, Pfizer, PierreâFabre, prIME Oncology, Roche, Sanofi, Samsung Bioepis, Seagen, Teva. SF is a consulting or advisory board member at Bayer, Illumina, Roche; has received honoraria from Amgen, Eli Lilly, PharmaMar, Roche; has received research funding from AstraZeneca, Pfizer, PharmaMar, Roche; has received sponsorship of travel or accommodation expenses by Amgen, Eli Lilly, Illumina, PharmaMar, Roche. SG owns AstraZeneca stock and is a fullâtime employee of AstraZeneca. PN has had an advisory role at Bayer, MSD Oncology, has received honoraria from Bayer, Novartis and MSD Oncology, and has had travel expenses paid by Novartis. JO has been an advisory board member at Roche, Novartis, Bayer, Merck, Eisai, Astrazeneca, Pierre Fabre Medicament and BristolâMyers Squibb. He has also received research funding by IPO Porto, Astrazeneca, Fundação para a Ciencia e a Tecnologia (FCT) and Liga Portuguesa Contra o Cancro (LPCC). AR is an employee of European Federation of Pharmaceutical Industries and Associations, Brussels, MSD International Business GmbH, Kriens, Switzerland[CvG1], and Merck Sharp & Dohme Corp., a subsidiary of Merck & Co., Inc., Kenilworth, NJ USA, who may own stock and/or hold stock options in the Company.RS serves as principal investigator of the ASCO TAPUR study. ASCO receives research grants from the following companies in support of the study: AstraâZeneca, Bayer, BoehringerâIngelheim, Bristol Myers Squibb, Genentech, Lilly, Merck, Pfizer, Seattle Genetics. Dr. Schilsky serves as a member of the managing board of Clariifi and as a consultant to Bryologyx, Cellworks Group, EQRx, and Scandion Oncology. The Netherlands Cancer Institute receives research support via EV from Roche, Astrazeneca, Eisai, Novartis, GSK, Clovis, BMS, MSD, Pfizer, Amgen, Bayer, Lilly, Janssen and Seagen. LZ is founder of everImmune, member of the board of directors of Transgene, member of the scientific advisory board of Transgene, EpiVax, Lytix Biopharma. LZ has also had research contracts with: Merus, Roche, Tusk, Kaleido, GSK, BMS, Incyte, Pileje, Innovate Pharma, and Transgene and has received honoraria by Transgene. All other authors have no conflicts of interest to declare.
Regarding the design of innovative and adaptive clinical trials, two examples were illustrated: the first European multimodular, twoâpart academic CCEâendorsed Basket of Baskets (BoB) study, and the recently launched CCE Building Data Rich Clinical Trials (DART) Consortium, which is supported by EUâs Horizon 2020 research and innovation programme (Box 13 ).
We are grateful for the support by Carolina Espina, International Agency for Research on Cancer; Christina von Gertten, European Academy of Cancer Sciences; Ana Augusta Silva, Portuguese Oncology Institute of Porto; and Teresa Tavares, Ministry of Science, Technology and Higher Education, Portugal for their excellent cooperation. Carmen Jeronimo, Portuguese Oncology Institute of Porto, collaborated in the presentation of Porto Comprehensive Cancer Center by Raquel Seruca
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