Formation Flight with Generating Functions: Solving the Relative Boundary Value Problem

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/77401/1/AIAA-2002-4639-277.pd

Lecciones clínicas sobre las enfermedades de la piel

Copia digital : Junta de Castilla y León. Consejería de Cultura y Turismo, 2016Pie de imp. del t.II: "Imprenta y librería de Moya y Plaza", en t.III "Imprenta y librería de Nicolás Moya"Pie de imp. en cub. del t.III: "Administracion de la Revista de Medicina y Cirugía Prácticas, 1895

In vitro activity of gentamicin, vancomycin or amikacin combined with EDTA or l-arginine as lock therapy against a wide spectrum of biofilm-forming clinical strains isolated from catheter-related infections.

International audienceOBJECTIVES: Treatment of catheter-related bloodstream infections (CRBSI) is hampered by the characteristic tolerance of bacterial biofilms towards antibiotics. Our objective was to study the effect of the combination of antibiotics and the alkaline amino acid l-arginine or the cation chelator EDTA on the bacterial killing of in vitro biofilms formed by an array of clinical strains responsible for CRBSI and representative of epidemiologically relevant bacterial species. METHODS: Among 32 strains described in a previous clinical study, we focused on the most antibiotic-tolerant strains including CoNS (n = 4), Staphylococcus aureus (n = 4), Enterococcus faecalis (n = 2), Pseudomonas aeruginosa (n = 4) and Enterobacteriaceae (n = 4). We used an in vitro biofilm model (96-well plate assay) to study biofilm tolerance and tested various combinations of antibiotics and non-antibiotic adjuvants. Gentamicin, amikacin or vancomycin was combined with disodium EDTA or l-arginine for 24 h to reproduce the antibiotic lock therapy (ALT) approach. Killing of biofilm bacteria was measured by cfu quantification after a vigorous step of pipetting up and down in order to detach all biofilm bacteria from the surface of the wells. RESULTS: Both of our adjuvant strategies significantly increased the effect of antibiotics against biofilms formed by Gram-positive and Gram-negative bacterial pathogens. The combination of gentamicin + EDTA was active against all tested strains apart from one P. aeruginosa. The combination of gentamicin + l-arginine was active against most of the tested strains with the notable exception of CoNS for which no potentiation was observed. We also demonstrated that amikacin + EDTA was active against Gram-negative bacteria and that vancomycin + EDTA was active against Gram-positive bacteria. CONCLUSIONS: The addition of EDTA enhanced the activity of gentamicin, amikacin and vancomycin against biofilms formed by a wide spectrum of bacterial strains responsible for CRBSI

Intestinal colonization due to Escherichia coli ST131: Risk factors and prevalence

Background Escherichia coli sequence type 131 (ST131) is a successful clonal group that has dramatically spread during the last decades and is considered an important driver for the rapid increase of quinolone resistance in E. coli. Methods Risk factors for rectal colonization by ST131 Escherichia coli (irrespective of ESBL production) were investigated in 64 household members (18 were colonized) and 54 hospital contacts (HC; 10 colonized) of 34 and 30 index patients with community and nosocomial infection due to these organisms, respectively, using multilevel analysis with a p limit of < 0.1. Result Colonization among household members was associated with the use of proton-pump inhibitors (PPI) by the household member (OR = 3.08; 95% CI: 0.88–10.8) and higher age of index patients (OR = 1.05; 95% CI; 1.01–1.10), and among HC, with being bed-ridden (OR = 21.1; 95% CI: 3.61–160.0) and having a urinary catheter (OR = 8.4; 95% CI: 0.87–76.9). Conclusion Use of PPI and variables associated with higher need of person-to-person contact are associated with increased risk of rectal colonization by ST131. These results should be considered for infection control purposes.Plan Nacional de I + D + i 2013-2016Ministerio de Economía y Competitividad (España)European Development Regional Fund REIPI RD12/0015/0010 REIPI RD16/0016/0001Instituto de Salud Carlos III 070190 AC16/000076-MODERN AC16/AC16/00072-ST131TSJunta de Andalucía CTS5259 CTS21

Stability of Surface Motion on a Rotating Ellipsoid

The dynamical environment on the surface of a rotating, massive ellipsoid is studied, with applications to surface motion on an asteroid. The analysis is performed using a combination of classical dynamics and geometrical analysis. Due to the small sizes of most asteroids, their shapes tend to differ from the classical spheroids found for the planets. The tri-axial ellipsoid model provides a non-trivial approximation of the gravitational potential of an asteroid and is amenable to analytical computation. Using this model, we study some properties of motion on the surface of an asteroid. We find all the equilibrium points on the surface of a rotating ellipsoid and we show that the stability of these points is intimately tied to the conditions for a Jacobi or MacLaurin ellipsoid of equilibria. Using geometrical analysis we can define global constraints on motion as a function of shape, rotation rate, and density, we find that some asteroids should have accumulation of material at their ends, while others should have accumulation of surface material at their poles. This study has implications for motion of a rover on an asteroid, and for the distribution of natural material on asteroids, and for a spacecraft hovering over an asteroid.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/42566/1/10569_2004_Article_5124207.pd

Physical and Link Layer in Power Line Communications Technologies

PLC technology1 - Power Line Communications- refers to the transmission of data using the domestic as well as the low-voltage electrical net. Depending on the type of network used as support it is divided in PLC indoor and outdoor. The first refers to the use of the domestic network and uses higher frequencies (5 MHz to 30 or 40 MHz). Outdoor PLC uses the distribution network and low frequencies of 1 MHz to 5 or 10 MHz. It employs the OFDM multiplexation technique- Orthogonal Frequency Division Multiplexing- which divides the frequency spectrum in narrow channels with independent carriers. At the level of media access protocol, it generally uses those which are compatible with the IEEE 802 norm, with controlled access to avoid collisions. OFDM modulation achieves transmission speeds which are suitable for multimedia services and applications as well as those of critical mission currently used, and with security conditions when facing a noisy channel such as the power network.II Workshop de Arquitecturas, Redes y Sistemas OperativosRed de Universidades con Carreras en Informática (RedUNCI

Physical and Link Layer in Power Line Communications Technologies

PLC technology1 - Power Line Communications- refers to the transmission of data using the domestic as well as the low-voltage electrical net. Depending on the type of network used as support it is divided in PLC indoor and outdoor. The first refers to the use of the domestic network and uses higher frequencies (5 MHz to 30 or 40 MHz). Outdoor PLC uses the distribution network and low frequencies of 1 MHz to 5 or 10 MHz. It employs the OFDM multiplexation technique- Orthogonal Frequency Division Multiplexing- which divides the frequency spectrum in narrow channels with independent carriers. At the level of media access protocol, it generally uses those which are compatible with the IEEE 802 norm, with controlled access to avoid collisions. OFDM modulation achieves transmission speeds which are suitable for multimedia services and applications as well as those of critical mission currently used, and with security conditions when facing a noisy channel such as the power network.II Workshop de Arquitecturas, Redes y Sistemas OperativosRed de Universidades con Carreras en Informática (RedUNCI

Quality of service and availability in a full mesh WAN using IP/MPLS : Case study: the network at the Department of Justice in Argentina

At the Argentine Department of Justice (Ministerio Público Fiscal de la República Argentina), a project is developed to set up a WAN with national coverage, quality of service, and IP/MPLS/VPN links. The project focuses on quality of service, a direct result from the selected technology. In previous work, studies explored these issues. Hence, the project enabled the implementation of the examined theory. The advantages of MPLS technology are evaluated to determine quality standards in VoIP, videoconference, mission critical appli-cations, e-mail, web access, and others. Other aspects of LANs are analyzed to obtain an availability level compatible to the required needs. The Project in-clude practical recommendations to adequate the LAN to the desired availability levels.IV Workshop Arquitectura, Redes y Sistemas Operativos (WARSO)Red de Universidades con Carreras en Informática (RedUNCI

Design of a Trans-Horizon radio link for ultra high and super high frequencies

Cost considerations and availability of frequencies condition the feasibility of links at distances in which there is no line of sight between antennas. These trans-horizon links require precise design procedures to determine whether the intensity of the signal and its noise ratio allow reception with reasonable quality. The present work describes a procedure for radio electric link calculation to transmit voice and data signals through bandwidth at ultra high and super high frequencies.Presentado en el V Workshop Arquitectura, Redes y Sistemas Operativos (WARSO)Red de Universidades con Carreras en Informática (RedUNCI