38,845 research outputs found
Evidence for the decay B0→J/ψω and measurement of the relative branching fractions of meson decays to J/ψη and J/ψη′
No full textFirst evidence of the B 0 → J / ψ ω decay is found and the B s 0 → J / ψ η and B s 0 → J / ψ η ′ decays are studied using a dataset corresponding to an integrated luminosity of 1.0 fb -1 collected by the LHCb experiment in proton-proton collisions at a centre-of-mass energy of sqrt(s) = 7 TeV. The branching fractions of these decays are measured relative to that of the B 0 → J / ψ ρ 0 decay:frac(B (B 0 → J / ψ ω), B (B 0 → J / ψ ρ 0)) = 0.89 ± 0.19 (stat) - 0.13 + 0.07 (syst),frac(B (B s 0 → J / ψ η), B (B 0 → J / ψ ρ 0)) = 14.0 ± 1.2 (stat) - 1.5 + 1.1 (syst) - 1.0 + 1.1 (frac(f d, f s)),frac(B (B s 0 → J / ψ η ′), B (B 0 → J / ψ ρ 0)) = 12.7 ± 1.1 (stat) - 1.3 + 0.5 (syst) - 0.9 + 1.0 (frac(f d, f s)), where the last uncertainty is due to the knowledge of f d / f s, the ratio of b-quark hadronization factors that accounts for the different production rate of B 0 and B s 0 mesons. The ratio of the branching fractions of B s 0 → J / ψ η ′ and B s 0 → J / ψ η decays is measured to befrac(B (B s 0 → J / ψ η ′), B (B s 0 → J / ψ η)) = 0.90 ± 0.09 (stat) - 0.02 + 0.06 (syst)
Letter from Carl Hayden to Henry F. Ashurst
No full textLetter describing three enclosures, a letter from F. M. Gold, Carl T. Hayden's reply to Gold's letter, and a copy of a bill introduced by Cameron
Multiband passive radar for drones detection and localization
No full textFor many surveillance systems, a multisensory architecture is essential when aiming
at providing accurate and reliable surveillance of critical infrastructures and
protected areas. This is certainly the case for airports, harbours, prisons and chemical
facilities as well as for public places such as parking areas, train stations or
stadiums, especially due to the new and emerging threat represented by commercial
drones and unmanned aerial vehicles (UAVs). In particular, their small size,
low radar reflectivity and flexibility of manoeuvre make them especially difficult to
detect, localize and classify. The potentials of passive radar (PR) in counter drone
operations, by exploiting different illuminators of opportunity (IOs), such as DVB-T,
DAB, GSM, WiFi, GNSS (Global Navigation Satellite Systems) and DVB-S that
were introduced in previous chapters, have been recently investigated in several
works. The reported results demonstrate that such sensors could be effectively
employed for detecting and localizing small and medium drones up to a few
kilometres from the PR receiver when DVB-T transmissions are exploited.
However, in urban areas and highly populated environments, where the use of the
non-invasive and green PR technology represents an attractive solution for enhancing
the security level, it is important to consider the possibility to exploit a
multisensory system by integrating PR with multiple operational frequency bands.
The integration of PRs operating at different frequency bands can be obtained
using two approaches:
1. A hardware integration can be conceived that provides a single multiband
sensor, which exploits a common multichannel receiver, common data
memory and common processing techniques for different signals of opportunity
and therefore greater frequency bandwidth.
2. At functional level, where each sensor operates with independent receiving
structures but the outputs of the multiple sensors are combined to provide
improved performance.
In the following sections, we proceed as follows. First, in Section 7.2, we
briefly review the most attractive sources of opportunity for an anti-drone PR
with their characteristics and signal processing requirements. Three specific
sources of opportunity are identified that appear to be well suited for a multiband
operation due to the complementarity of their characteristics. Therefore, we
illustrate the concept of the multisensory system on the basis of the parasitic
exploitation of such signals and discuss possible implementations and benefits.
The different components of the multisensory system are then separately
addressed in Sections 7.3–7.5 which are devoted respectively to anti-drone PR
based on DVB-S satellite broadcast signals, DVB-T terrestrial TV and WiFi, in
order to analyse the specific characteristics of their sensors as well as their performance.
This analysis also allows to identify hardware and signal processing
requirements for an effective implementation of the integrated multiband PR
system
On the {2}-domination number of graphs
No full text[EN] Let G be a nontrivial graph and k ¿ 1 an integer. Given a vector of nonnegative integers
w = (w0,...,wk), a function f : V(G) ¿ {0,..., k} is a w-dominating function on G if f(N(v)) ¿ wi
for every v ¿ V(G) such that f(v) = i. The w-domination number of G, denoted by ¿w(G), is the
minimum weight ¿(f) = ¿v¿V(G)
f(v) among all w-dominating functions on G. In particular, the {2}-
domination number of a graph G is defined as ¿{2}
(G) = ¿(2,1,0)
(G). In this paper we continue with
the study of the {2}-domination number of graphs. In particular, we obtain new tight bounds on this
parameter and provide closed formulas for some specific families of graphs.Cabrera-Martínez, A.; Conchado Peiró, A. (2022). On the {2}-domination number of graphs. AIMS Mathematics. 7(6):10731-10743. https://doi.org/10.3934/math.2022599S107311074376T. W. Haynes, S. T. Hedetniemi, P. J. Slater, Fundamentals of Domination in Graphs, Chapman and Hall/CRC Pure and Applied Mathematics Series, Marcel Dekker, Inc. New York, 1998.T. W. Haynes, S. T. Hedetniemi, P. J. Slater, Fundamentals of Domination in Graphs: Advanced Topics, Chapman & Hall/CRC Pure and Applied Mathematics, Taylor & Francis, 1998.T. W. Haynes, S. T. Hedetniemi, M. A. Henning, Topics in Domination in Graphs, Springer International Publishing, Cham, 2020. https://doi.org/10.1007/978-3-030-51117-3A. Cabrera Martínez, A. Estrada-Moreno, J. A. Rodríguez-Velázquez, From Italian domination in lexicographic product graphs to -domination in graphs, ARS Math. Contemp., 22 (2022), P1.04. https://doi.org/10.26493/1855-3974.2318.fb9M. A. Henning, A. Yeo, Total Domination in Graphs, Springer Monographs in Mathematics, 2013. https://doi.org/10.1007/978-1-4614-6525-6M. A. Henning, A survey of selected recent results on total domination in graphs, Discrete Math., 309 (2009), 32–63. https://doi.org/10.1016/j.disc.2007.12.044F. Bonomo, B. Brešar, L. N. Grippo, M. Milanič, M. D. Safe, Domination parameters with number 2: interrelations and algorithmic consequences, Discrete Appl. Math., 235 (2018), 23–50. https://doi.org/10.1016/j.dam.2017.08.017A. Cabrera Martínez, J. A. Rodríguez-Velázquez, A note on double domination in graphs, Discrete Appl. Math., 300 (2021), 107–111. https://doi.org/10.1016/j.dam.2021.05.011A. Hansberg, L. Volkmann, Multiple domination, In: Topics in domination in graphs, vol. 64 of Dev. Math., Springer, Cham (2020), 151–203. https://doi.org/10.1007/978-3-030-51117-3_6F. Harary, T. W. Haynes, Double domination in graphs, Ars Combin., 55 (2000), 201–213.M. Chellali, T. W. Haynes, S. T. Hedetniemi, A. A. McRae, Roman -domination, Discrete Appl. Math., 204 (2016), 22–28. https://doi.org/10.1016/j.dam.2015.11.013M. A. Henning, W. F. Klostermeyer, Italian domination in trees, Discrete Appl. Math., 217 (2017), 557–564. https://doi.org/10.1016/j.dam.2016.09.035W. F. Klostermeyer, G. MacGillivray, Roman, Italian, and domination, J. Combin. Math. Combin. Comput., 108 (2019), 125–146.S. Cabrera García, A. Cabrera Martínez, F. A. Hernández Mira, I. G. Yero, Total Roman -domination in graphs, Quaest. Math., 44 (2021), 411–434. https://doi.org/10.2989/16073606.2019.1695230H. Abdollahzadeh Ahangar M. Chellali, S. M. Sheikholeslami, J. C. Valenzuela-Tripodoro, Total Roman -dominating functions in graphs, Discuss. Math. Graph Theory, (2020), In press. https://doi.org/10.7151/dmgt.2316A. Cabrera Martínez, S. Cabrera García, J. A. Rodríguez-Velázquez, Double domination in lexicographic product graphs, Discrete Appl. Math., 284 (2020), 290–300. https://doi.org/10.1016/j.dam.2020.03.045B. Brešar, M. A. Henning, S. Klavžar, On integer domination in graphs and Vizing-like problems, Taiwanese J. Math., 10 (2006), 1317–1328. https://doi.org/10.11650/twjm/1500557305G. S. Domke, S. T. Hedetniemi, R. C. Laskar, G. H. Fricke, Relationships between integer and fractional parameters of graphs, In: Graph theory, combinatorics, and applications: proceedings of the Sixth Quadrennial International Conference on the Theory and Applications of Graphs, Western Michigan University, volume 2, John Wiley & Sons Inc. (1991), 371–387.X. Hou, Y. Lu, On the -domination number of cartesian products of graphs, Discrete Math., 309 (2009), 3413–3419.C. M. Lee, M. S. Chang, Variations of -dominating functions on graphs, Discrete Math., 308 (2008), 4185–4204. https://doi.org/10.1016/j.disc.2007.08.080A. Cabrera Martínez, I. G. Yero, Constructive characterizations concerning weak Roman domination in trees, Discrete Appl. Math., 284 (2020), 384–390. https://doi.org/10.1016/j.dam.2020.03.058A. Cabrera Martínez, D. Kuziak, I. G. Yero. A constructive characterization of vertex cover Roman trees, Discuss. Math. Graph Theory, 41 (2021), 267–283. https://doi.org/10.7151/dmgt.2179W. J. Desormeaux, T. W. Haynes, M. A. Henning, Improved bounds on the domination number of a tree, Discrete Appl. Math., 177 (2014), 88–94. https://doi.org/10.1016/j.dam.2014.05.037G. S. Domke, J. H. Hattingh, M. A. Henning, L. R. Markus, Restrained domination in trees, Discrete Math., 211 (2000), 1–9. https://doi.org/10.1016/S0012-365X(99)00036-9M. Chellali, T. W. Haynes, A note on the total domination of a tree, J. Comb. Math. Comb. Comput., 58 (2006), 189–193.M. Lemanska, Lower bound on the domination number of a tree. Discuss. Math. Graph Theory, 24 (2004), 165–169. https://doi.org/10.7151/dmgt.1222E. Shan, L. Kang, M. A. Henning, A characterization of trees with equal total domination and paired-domination numbers, Australas. J. Comb., 30 (2004), 31–39.A. Cabrera Martínez, A. Estrada-Moreno, J. A. Rodríguez-Velázquez, From (secure) w-domination in graphs to protection of lexicographic product graphs, Bull. Malays. Math. Sci. Soc., 44 (2021), 3747–3765. https://doi.org/10.1007/s40840-021-01141-8A. Cabrera Martínez, A. Estrada-Moreno, J. A. Rodríguez-Velázquez, Secure w-domination in graphs, Symmetry, 12 (2020), 1948. https://doi.org/10.3390/sym1212194
The long-wavelength view of GG Tau A: rocks in the ring world
No full textWe present the first detection of GG Tau A at centimetre wavelengths, made with the Arcminute Microkelvin Imager Large Array at a frequency of 16 GHz (λ = 1.8 cm). The source is detected at >6 σrms with an integrated flux density of S16GHz = 249 ± 45 µJy. We use these new centimetre-wave data, in conjunction with additional measurements compiled from the literature, to investigate the long-wavelength tail of the dust emission from this unusual protoplanetary system. We use an MCMC-based method to determine maximum likelihood parameters for a simple parametric spectral model and consider the opacity and mass of the dust contributing to the microwave emission. We derive a dust mass of Md ~ 0.1 Msun, constrain the dimensions of the emitting region and find that the opacity index at λ > 7 mm is less than unity, implying a contribution to the dust population from grains exceeding ~4 cm in size. We suggest that this indicates coagulation within the GG Tau A system has proceeded to the point where dust grains have grown to the size of small rocks with dimensions of a few centimetres. Considering the relatively young age of the GG Tau association in combination with the low derived disc mass, we suggest that this system may provide a useful test case for rapid core accretion planet formation models
Brainstem cavernous angioma in an octagenarian cardiopathic patient: anesthesiologic and neurosurgical challanges
No full textLearning Track: 6. Neuroanaesthesiology
Title: Brainstem cavernous angioma in an octogenarian cardiopathic patient: anesthesiologic and neurosurgical challenges
Author(s): Urli T.1, Nicolini F.2, Giulioni M.2, Sturiale C.2, Zanello M.1
Institute(s): 1IRCCS Istituto delle Scienze Neurologiche, Bellaria Hospital, Anesthesia and Intensive Care, Bologna, Italy, 2IRCCS Istituto delle Scienze Neurologiche, Bellaria Hospital, Neurosurgery, Bologna, Italy
Text: Background: Cerebral cavernous angiomas are uncommon diseases mostly affecting young and middle-aged people. Brainstem location can be related to severe complications both in cases of conservative or surgical management. Anesthesiologic concern is the hemodynamic instability due to manipulation of brainstem (dysrhythmias, hypertension, hypotension), and the risk of cranial nerves dysfunction.
Case report: A 81-year-old male presented painful dysesthesias and gait instability. The Magnetic Resonance Imaging revealed a large hemorrhagic multicystic lesion in the medulla oblongata. The patient had a cardiac disease with previous heart surgery (biological prosthesis, Bentall procedure); the artificial aortic valve was degenerating with moderate regurgitation. According to patient will, surgical intervention was scheduled for reducing the brainstem compression and the risk of rebleeding. Preoperative anesthesiologic evaluation pointed out the high risk of the procedure. The anesthetic plan included: prone position, balanced anesthesia with midazolam, sevoflurane and remifentanil, endocarditis prophylaxis, and a hemodynamic management fit for a patient with aortic regurgitation. External pacemaker-defibrillator pads were applied in advance. Surgical resection was carried out until occurrence of sudden bradycardia with hypotension, managed with atropine. After a short stay in ICU, the patient was transferred to the ward and then to the rehabilitation unit. Postoperatively he presented hemiparesis, slowly improving after physical therapy. The histopathological analysis confirmed the diagnosis of cavernoma.
Discussion: We found no previous report of brainstem cavernoma surgery in octogenarian cardiopathic patients, but advanced age is not a sufficient reason to deny surgical treatment if the patient may benefit. In this case the usual concern about intraoperative hemodynamic instability was increased by the type of cardiac valvulopathy: intraoperative dysrhythmias, especially bradycardia, can worsen the degree of aortic regurgitation and can precipitate left ventricular failure. The medical team weighted carefully risk benefit ratio as well as the patient wish.
Learning points: Neurosurgery of brainstem cavernomas can be performed in selected elderly patients in Hospitals with specific neurosurgical and anesthesiologic experience. The presence of serious comorbidities should not rule out the possibility of anesthesiologic and surgical treatment.
Preferred Presentation Type: Case report
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Conference: Euroanaesthesia 2017 · Abstract: A-805-0061-00727 · Status: Draf
Hypnea tsudae M. O. Paiano F. P. Cabrera & A. R. Sherwood 2022, sp. nov.
No full textHypnea tsudae M.O.Paiano F.P.Cabrera & A.R.Sherwood, sp. nov. (Fig. 4 A-H) Holotype: — U.S.A. Hawai‘i, Pu‘ukohala Heiau National Park, Island of Hawai‘i 20.748°N, 24.384°W, 1.5 m depth, 03 August 2006, C. Squair (holotype BISH 740394). Paratypes: — ARS 03115 (BISH 786150) from U.S.A. Hawai‘i, Island of Maui, Hana, Kaihalulu Beach, 20.7589°N, 155.985°W, intertidal, 10 December 2007, K. Conklin; ARS 03542 (BISH 786151) from U.S.A. Hawai‘i, Island of Kauai, 22.2208°N, 159.583°W, intertidal, 17 March 2007, A. Kurihara. Description: Thalli upright, terete, ranging from 1.2–4.5 cm in length (Figs 4A–C), usually rich red in color when living, drying to a light pink to orange when pressed (Fig 4A). Thalli are compressed with thorn-like branchlets that are often dichotomously branched at the apices and alternately branched in the mid to basal portions (Figs 4D–E). Branching most often in three-dimensional space (Figs 4A–E). In surface view, thallus is composed of small cortical cells, elongated, 4.0–7.5 μm in length and 2.0–10.8 μm in diameter (Fig 4F). Axes uniaxial, rounded. Transverse sections 310–440 μm in diameter (Figs 4G–H). Each axial cell surrounded by three to five periaxial cells (Figs 4G–H), 38–45 μm in diameter, surrounded by two to four layers of large, rounded to cuboidal medullary cells, 30–98 μm in length and 20–60 μm in width. Holdfast not observed. Only sterile plants observed. Etymology:— This species is named in memory of our colleague, Dr. Roy Tsuda, who made many contributions to our understanding of the flora of the Western Pacific, and who collaborated with us extensively on the taxonomy of the mesophotic flora of the Hawaiian Islands and the Papahânaumokuâkea Marine National Monument. Distribution and Habitat:— subtidal from Island of Hawai‘i, intertidal coastal waters of Maui and Kaua‘i, in the Main Hawaiian Islands, USA. Identification using DNA sequence data:— GenBank accessions OL 795917 (COI), OL 795918 (rbc L) and OL 828741 (SSU) for the holotype, ON 704651 (ARS 03115) and ON 704652 (ARS 03542) (rbc L) for the paratypes.Published as part of Paiano, Monica O., Fumo, James T., Cabrera, Feresa P., Kosaki, Randall K., Spalding, Heather L. & Sherwood, Alison R., 2022, Calliblepharis yasutakei sp. nov. and Hypnea tsudae sp. nov. (Cystocloniaceae, Rhodophyta): novel diversity from the Hawaiian Islands, pp. 74-86 in Phytotaxa 572 (1) on page 82, DOI: 10.11646/phytotaxa.572.1.5, http://zenodo.org/record/730572
Low-latitude equinoctial spread-F occurrence at different longitude sectors under low solar activity
No full textWe present the results of a comparative study of spread-F signatures over five low-latitude sites: Chiangmai (CGM; 18.8° N, 98.9° E, mag. Lat. 8.8° N), Thailand; Tanjungsari (TNJ; 6.9° S, 107.6° E, mag. Lat. 16.9° S), Indonesia; Palmas (PAL; 10.2° S, 311.8° E, mag. Lat. 0.9° S) and São José Dos Campos (SJC; 23.2° S, 314.1° E, mag. Lat. 14.0° S), Brazil; and Tucumán (TUC; 26.9° S, 294.6° E, mag. Lat. 16.8° S), Argentina. The investigation was based on simultaneous ionograms recorded by an FMCW (frequency-modulated continuous-wave) at CGM, an IPS-71 (digital ionosonde from KEL aerospace) at TNJ, a CADI (Canadian Advanced Digital Ionosonde) at PAL and SJC, and an AIS-INGV (Advanced Ionospheric Sounder – Istituto Nazionale di Geofisica e Vulcanologia) at TUC, during the equinoctial periods March–April (R12 = 2.0 and R12 = 2.2) and September–October (R12 = 6.1 and R12 = 7.0) 2009, for very low solar activity. Spread-F signatures were categorized into two types: the range spread-F (RSF) and the frequency spread-F (FSF). The study confirms that the dynamics and the physical processes responsible for these phenomena are actually complicated. In fact, the features that arise from the investigation are different, depending on both the longitude sector and on the hemisphere. For instance, TUC, under the southern crest of the ionospheric equatorial ionization anomaly (EIA), shows a predominance of RSF signatures, while both SJC, under the southern crest of EIA but in a different longitude sector, and CGM, under the northern crest of EIA, show a predominance of FSF signatures. Moreover, the spread-F occurrence over the longitude sector that includes CGM and TNJ is significantly lower than the spread-F occurrence over the longitude sector of PAL, SJC, and TUC.Fil: Pezzopane, M.. Istituto Nazionale Di Geofisica E Vulcanologia; Italia;Fil: Zuccheretti, E.. Istituto Nazionale Di Geofisica E Vulcanologia; Italia;Fil: Abadi, P.. Indonesian National Institute of Aeronautics and Space. Space Science Center. Division of Ionosphere and Telecommunication; Indonesia;Fil: de Abreu, A. J.. Universidade do Vale do Paraíba; Brazil;Fil: de Jesus, R.. Universidade do Vale do Paraíba; Brazil;Fil: Fagundes, P. R.. Universidade do Vale do Paraíba; Brazil;Fil: Supnithi, P.. King Mongkut’s Institute of Technology Ladkrabang . Faculty of Engineering; Tailandia;Fil: Rungraengwajiake, S.. King Mongkut’s Institute of Technology Ladkrabang . Faculty of Engineering; Tailandia;Fil: Nagatsuma, T.. National Institute of Information and Communications Technology. Space Weather and Environment Informatics Laboratory; Japón;Fil: Tsugawa, T.. National Institute of Information and Communications Technology. Space Weather and Environment Informatics Laboratory; Japón;Fil: Cabrera, Miguel Angel. Universidad Nacional de Tucumán. Facultad de Ciencias Exactas y Tecnología. Departamento de Física. Laboratorio de Ionosfera; Argentina; Universidad Nacional de Tucumán. Facultad de Ciencias Exactas y Tecnología. Departamento de Electricidad, Electrónica y Computación. Laboratorio de Telecomunicaciones; Argentina; Universidad Tecnológica Nacional. Facultad Regional Tucumán. Centro de Investigación de Atmósfera Superior y Radiopropagación; Argentina;Fil: Ezquer, Rodolfo Gerardo. Universidad Tecnológica Nacional. Facultad Regional Tucumán. Centro de Investigación de Atmósfera Superior y Radiopropagación; Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina; Universidad Nacional de Tucumán. Facultad de Ciencias Exactas y Tecnología. Departamento de Física. Laboratorio de Ionosfera; Argentina
Public health observatories: A learning community model to foster knowledge transfer for sustainable cities
No full textA Public Health Observatory (PHO) is a platform to provide “health intelligence” as a service for a specific population. The World Health Organization (WHO) identifies the primary purposes of PHOs as “monitoring health situations and trends, including assessing progress toward agreed-upon health-related targets; producing and sharing evidence; and, supporting the use of such evidence for policy and decision making” For the purposes of the PULSE project, create an observatory to function as a unique point of access to the PULSE technology for people both inside and outside the project consortium.Specifically, we create a platform for e-learning and knowledge sharing that it can be easily navigated by lay persons that are interested in learning about or participating in the PULSE project. We targeted specifically policymakers, clinicians, as well as leaders and citizens in other cities. As a concept, it reflects the principles participation, sustainability, and collaboration across sectors and levels of government The Observatory leverages on the Health in All Policies (HiAP) framework. HiAP is a cross-sectoral approach to public policy that systematically takes into account the health implications of decisions, seeks synergies, and avoids harmful health impacts in order to improve population health and health equity
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