27 research outputs found
Genetic features of verotoxigenic Escherichia coli O157:H7 isolated from clinical cases of Argentina and Chile
No full textWe aimed to compare the genetic diversity existing in VTEC O157:H7 strains isolated from cases of human disease from Argentina and Chile. For it, 76 strains were studied in relation to the distribution of genes encoding virulence factors and subtyped by lineage-specific polymorphisms (LSPA-6), and phylogroups assignment. Our results show the almost exclusive circulation of VTEC O157:H7 isolates belonging to lineage I/II, associated with hypervirulent strains, and to the phylogroup E and, on the other hand, genetic diversity present among Argentinean and Chilean strains analyzed, mainly in relation to putative virulence determinants and nle profiles.Fil: González, Juliana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil. Centro de Investigación Veterinaria de Tandil. Universidad Nacional del Centro de la Provincia de Buenos Aires. Centro de Investigación Veterinaria de Tandil. Provincia de Buenos Aires. Gobernación. Comision de Investigaciones Científicas. Centro de Investigación Veterinaria de Tandil; ArgentinaFil: Cadona, Jimena Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil. Centro de Investigación Veterinaria de Tandil. Universidad Nacional del Centro de la Provincia de Buenos Aires. Centro de Investigación Veterinaria de Tandil. Provincia de Buenos Aires. Gobernación. Comision de Investigaciones Científicas. Centro de Investigación Veterinaria de Tandil; ArgentinaFil: Zotta, Claudio Marcelo. Dirección Nacional de Instituto de Investigación.Administración Nacional de Laboratorios e Institutos de Salud "Dr. Carlos G. Malbrán"; ArgentinaFil: Lavayén, Silvina. Dirección Nacional de Instituto de Investigación.Administración Nacional de Laboratorios e Institutos de Salud "Dr. Carlos G. Malbrán"; ArgentinaFil: Vidal, Roberto. Universidad de Chile. Facultad de Medicina; ChileFil: Padola, Nora Lía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil. Centro de Investigación Veterinaria de Tandil. Universidad Nacional del Centro de la Provincia de Buenos Aires. Centro de Investigación Veterinaria de Tandil. Provincia de Buenos Aires. Gobernación. Comision de Investigaciones Científicas. Centro de Investigación Veterinaria de Tandil; ArgentinaFil: Sanso, Andrea Mariel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil. Centro de Investigación Veterinaria de Tandil. Universidad Nacional del Centro de la Provincia de Buenos Aires. Centro de Investigación Veterinaria de Tandil. Provincia de Buenos Aires. Gobernación. Comision de Investigaciones Científicas. Centro de Investigación Veterinaria de Tandil; ArgentinaFil: Bustamante, Ana Victoria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil. Centro de Investigación Veterinaria de Tandil. Universidad Nacional del Centro de la Provincia de Buenos Aires. Centro de Investigación Veterinaria de Tandil. Provincia de Buenos Aires. Gobernación. Comision de Investigaciones Científicas. Centro de Investigación Veterinaria de Tandil; Argentin
Uniqueness and nonuniqueness of the GNSS carrier-phase compass readings
No full textIn this contribution we analyse the possible nonuniqueness in the least-squares solution of the GNSS carrier-phase compass model. It is shown that this lack of uniqueness may manifest itself in the fixed baseline estimator and therefore in the GNSS compass readings. We present the conditions under which nonuniqueness occurs and give explicit expressions for these nonunique least-squares solutions.Remote SensingAerospace Engineerin
Multidrug resistance and molecular characterization of streptococcus agalactiae isolates from dairy cattle with mastitis
No full textStreptococcus agalactiae is a pathogen-associated to bovine mastitis, a health disorder responsible for significant economic losses in the dairy industry. Antimicrobial therapy remains the main strategy for the control of this bacterium in dairy herds and human In order to get insight on molecular characteristics of S. agalactiae strains circulating among Argentinean cattle with mastitis, we received 1500 samples from 56 dairy farms between 2016 and 2019. We recovered 56 S. agalactiae isolates and characterized them in relation to serotypes, virulence genes, and antimicrobial susceptibility. Serotypes III and II were the most prevalent ones (46% and 41%, respectively), followed by Ia (7%). In relation to the 13 virulence genes screened in this study, the genes spb1, hylB, cylE, and PI-2b were present in all the isolates, meanwhile, bca, cpsA, and rib were detected in different frequencies, 36%, 96%, and 59%, respectively. On the other hand, bac, hvgA, lmb, PI-1, PI-2a, and scpB genes could not be detected in any of the isolates. Disk diffusion method against a panel of eight antimicrobial agents showed an important number of strains resistant simultaneously to five antibiotics. We also detected several resistance-encoding genes, tet(M), tet(O), ermB, aphA3, and lnu(B) (9%, 50%, 32%, 32%, and 5%, respectively). The results here presented are the first molecular data on S. agalactiae isolates causing bovine mastitis in Argentina and provide a foundation for the development of diagnostic, prophylactic, and therapeutic methods, including the perspective of a vaccine.Fil: Hernandez, Luciana Belén. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil. Centro de Investigación Veterinaria de Tandil. Universidad Nacional del Centro de la Provincia de Buenos Aires. Centro de Investigación Veterinaria de Tandil. Provincia de Buenos Aires. Gobernación. Comision de Investigaciones Científicas. Centro de Investigación Veterinaria de Tandil; ArgentinaFil: Bottini, Enriqueta. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil. Centro de Investigación Veterinaria de Tandil. Universidad Nacional del Centro de la Provincia de Buenos Aires. Centro de Investigación Veterinaria de Tandil. Provincia de Buenos Aires. Gobernación. Comision de Investigaciones Científicas. Centro de Investigación Veterinaria de Tandil; ArgentinaFil: Cadona, Jimena Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil. Centro de Investigación Veterinaria de Tandil. Universidad Nacional del Centro de la Provincia de Buenos Aires. Centro de Investigación Veterinaria de Tandil. Provincia de Buenos Aires. Gobernación. Comision de Investigaciones Científicas. Centro de Investigación Veterinaria de Tandil; ArgentinaFil: Cacciato, Claudio Santiago. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil. Centro de Investigación Veterinaria de Tandil. Universidad Nacional del Centro de la Provincia de Buenos Aires. Centro de Investigación Veterinaria de Tandil. Provincia de Buenos Aires. Gobernación. Comision de Investigaciones Científicas. Centro de Investigación Veterinaria de Tandil; ArgentinaFil: Monteavaro, Cristina Esther. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil. Centro de Investigación Veterinaria de Tandil. Universidad Nacional del Centro de la Provincia de Buenos Aires. Centro de Investigación Veterinaria de Tandil. Provincia de Buenos Aires. Gobernación. Comision de Investigaciones Científicas. Centro de Investigación Veterinaria de Tandil; ArgentinaFil: Bustamante, Ana Victoria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil. Centro de Investigación Veterinaria de Tandil. Universidad Nacional del Centro de la Provincia de Buenos Aires. Centro de Investigación Veterinaria de Tandil. Provincia de Buenos Aires. Gobernación. Comision de Investigaciones Científicas. Centro de Investigación Veterinaria de Tandil; ArgentinaFil: Sanso, Andrea Mariel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil. Centro de Investigación Veterinaria de Tandil. Universidad Nacional del Centro de la Provincia de Buenos Aires. Centro de Investigación Veterinaria de Tandil. Provincia de Buenos Aires. Gobernación. Comision de Investigaciones Científicas. Centro de Investigación Veterinaria de Tandil; Argentin
The future of single-frequency integer ambiguity resolution
No full textThe coming decade will bring a proliferation of Global Navigation Satellite Systems (GNSSs) that are likely to enable a much wider range of demanding applications compared to the current GPS-only situation. One such important area of application is single-frequency real-time kinematic (RTK) positioning. Presently, however, such systems lack real-time performance. In this contribution we analyze the ambiguity resolution performance of the single-frequency RTK model for different next generation GNSS configurations and positioning scenarios. For this purpose, a closed form expression of the single-frequency Ambiguity Dilution of Precision (ADOP) is derived. This form gives a clear insight into how and to what extent the various factors of the underlying model contribute to the overall performance. Analytical and simulation results will be presented for different measurement sce arios. The results indicate that low-cost, single-frequency GalileoCGPS RTK will become a serious competitor to its more expensive dual-frequency cousin.Space EngineeringAerospace Engineerin
High-resolution gamma-camera for molecular breast imaging: First clinical results
No full textScintimammography is a molecular breast imaging technique using tumour-seeking radiopharmaceuticals; with standard gamma-cameras, it proved of value especially when mammography is indeterminate and in women with dense breasts; nevertheless, this technique shows a high sensitivity only for cancers > 1 cm. The issue of detecting small cancers is critical for the future development and clinical usefulness of breast imaging with radiopharmaceuticals, because other modalities are increasingly employed for early identification of small abnormalities. The use of high-resolution dedicated cameras for breast imaging is the best option to improve small cancers' detection: they allow greater flexibility in patient positioning, and the availability of projections similar to those of mammography. Moreover, the detector can be placed directly against the breast, and a mild compression is possible, with the results of reducing breast thickness, increasing the target-to-background ratio and the sensitivity. Our first clinical findings using the dedicated camera Lumagem 3200S (Gamma Medica, Inc., Northridge, USA) are very satisfactory. Till now, 29 patients with BI-RADS category III and IV lesions ≤ 1cm were prospectively evaluated using a conventional gamma-camera and the dedicated device. Four out nine (44%) of the malignant lesions were detected with the standard gamma-camera, whereas the high-resolution camera visualized all the breast cancers. The standard gamma-camera and the dedicated one showed the same specificity: 19 out of 20 (95%) benign lesions were negative. Our results indicate that molecular breast imaging with this dedicated camera is able to detect small cancers in patients with probably benign or low-suspicion to indeterminate mammographic findings
Integer ambiguity resolution with nonlinear geometrical constraints
No full textInteger ambiguity resolution is the key to obtain very accurate positioning solutions out of the GNSS observations. The Integer Least Squares (ILS) principle, a derivation of the least-squares principle applied to a linear system of equations in which some of the unknowns are subject to an integer constraint,was demonstrated to be optimal among the class of admissible integer estimators. In this contribution it is shown how to embed into the functional model a set of nonlinear geometrical constraints, which arise when considering a set of antennae mounted on a rigid platform. A method to solve for the new model is presented and tested: it is shown that the strengthened underlying model leads to an improved capacity of fixing the correct integer ambiguities.Remote SensingAerospace Engineerin
The International Atomic Energy Agency International Doubly Labelled Water Database : Aims, Scope and Procedures
No full textFunding Sources The database is generously supported by the IAEA and by the companies Taiyo Nippon Sanso, SERCON and ISOTEC. We are grateful to these companies for their support and especially to Takashi Oono for his tremendous efforts at fund raising on our be half. The authors also gratefully acknowledge funding from the US National Science Foundation (BCS-1824466) awarded to Herman Pontzer. The funders played no role in the content of this manuscript. Open access provided with a grant from the International Atomic Energy Agency. Author Contributions All authors contributed to the drafting and editing of the manuscript and to construction of the IAEA DLW database.Peer reviewe
Next generation GNSS single receiver cycle slip reliability
No full textIn this contribution we study the multi-frequency, carrier-phase slip detection capabilities of a single receiver. Our analysis is based on an analytical expression that we present for themulti-frequencyminimal detectable carrier phase cycle slip.Remote SensingAerospace Engineerin
Design Solutions For Modular Satellite Architectures
No full textThe cost-effective access to space envisaged by ESA would open a wide range of new opportunities and markets, but is still many years ahead. There is still a lack of devices, circuits, systems which make possible to develop satellites, ground stations and related services at costs compatible with the budget of academic institutions and small and medium enterprises (SMEs). As soon as the development time and cost of small satellites will fall below a certain threshold (e.g. 100,000 to 500,000 €), appropriate business models will likely develop to ensure a cost-effective and pervasive access to space, and related infrastructures and services. These considerations spurred the activity described in this paper, which is aimed at: - proving the feasibility of low-cost satellites using COTS (Commercial Off The Shelf) devices. This is a new trend in the space industry, which is not yet fully exploited due to the belief that COTS devices are not reliable enough for this kind of applications; - developing a flight model of a flexible and reliable nano-satellite with less than 25,000€; - training students in the field of avionics space systems: the design here described is developed by a team including undergraduate students working towards their graduation work. The educational aspects include the development of specific new university courses; - developing expertise in the field of low-cost avionic systems, both internally (university staff) and externally (graduated students will bring their expertise in their future work activity); - gather and cluster expertise and resources available inside the university around a common high-tech project; - creating a working group composed of both University and SMEs devoted to the application of commercially available technology to space environment. The first step in this direction was the development of a small low cost nano-satellite, started in the year 2004: the name of this project was PiCPoT (Piccolo Cubo del Politecnico di Torino, Small Cube of Politecnico di Torino). The project was carried out by some departments of the Politecnico, in particular Electronics and Aerospace. The main goal of the project was to evaluate the feasibility of using COTS components in a space project in order to greatly reduce costs; the design exploited internal subsystems modularity to allow reuse and further cost reduction for future missions. Starting from the PiCPoT experience, in 2006 we began a new project called ARaMiS (Speretta et al., 2007) which is the Italian acronym for Modular Architecture for Satellites. This work describes how the architecture of the ARaMiS satellite has been obtained from the lesson learned from our former experience. Moreover we describe satellite operations, giving some details of the major subsystems. This work is composed of two parts. The first one describes the design methodology, solutions and techniques that we used to develop the PiCPoT satellite; it gives an overview of its operations, with some details of the major subsystems. Details on the specifications can also be found in (Del Corso et al., 2007; Passerone et al, 2008). The second part, indeed exploits the experience achieved during the PiCPoT development and describes a proposal for a low-cost modular architecture for satellite
Caracterización molecular de Streptococcus agalactiae aislado de tambos de la Cuenca Mar y Sierras de Argentina
No full textLa cuenca de Mar y Sierras es una de las principales regiones lecheras de Argentina, ya que produce aproximadamente 1100000 litros de leche diarios. Cuenta con aproximadamente 160 tambos. La mastitis bovina es la enfermedad de mayor incidencia en la producción lechera. Streptococcus agalactiae (Estreptococo β hemolítico del Grupo B o EGB) produce mastitis clínica y subclínica en bovinos, y en consecuencia, causa pérdidas económicas importantes para los tambos afectados. Es un patógeno prácticamente obligado de la glándula mamaria, con muy baja viabilidad, y se comporta como un agente altamente contagioso. La capacidad de colonizar e invadir al huésped se ha relacionado con una serie de factores de virulencia, entre los cuales el polisacárido capsular (CPS) es el primero que permite a la bacteria evadir el sistema inmune e invadir el huésped. De acuerdo al tipo de CPS se han identificado 10 serotipos. En este estudio, analizamos serotipos y perfiles de virulencia en 40 aislamientos bovinos de S. agalactiae, obtenidos de tambos ubicados en la cuenca de Mar y Sierras (Provincia de Buenos Aires). La tipificación de tipos capsulares se realizó por PCR y, además, se amplificaron los genes de virulencia bac, bca, lmb, rib y spb1, que están asociados con la adhesión, invasión, y/o evasión inmune. Los resultados mostraron diversidad genética en relación a factores de virulencia y a serotipos. Se detectaron 4 perfiles de virulencia y 5 tipos capsulares, Ia (2.5 %), II (15 %), III (50 %), IV (17.5 %), VIII (2.5 %) y cinco aislamientos se clasificaron como no tipificables (NT). Entre los genes de virulencia examinados, spb1 fue el más prevalente (87.5 %), detectándose sólo (60 %) o en combinación con otro/s genes, spb1- rib (25 %) o spb1- rib- bca (13 %). Por otra parte, los genes lmb y bac no fueron detectados en los aislamientos analizados. De acuerdo con el análisis de agrupamiento las cepas estudiadas se dividieron en dos grupos principales: i) aislamientos tipificables y con algún gen de virulencia y, ii) aislamientos NT y sin genes de virulencia. Dentro del primer grupo se diferenciaron, a su vez, dos subgrupos: ia) aislamientos de serotipo III, y, ib) aislamientos de serotipos diferentes del III, 93% rib-negativos. El gen spb1 codificante de una proteína implicada en la adherencia a las células epiteliales fue detectado en la mayoría de las cepas, mostrando una prevalencia diferente a la descripta en otras regiones geográficas, en donde principalmente se lo ha encontrado asociado a cepas de humanos.Fil: Hernandez, Luciana Belén. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil. Centro de Investigación Veterinaria de Tandil. Universidad Nacional del Centro de la Provincia de Buenos Aires. Centro de Investigación Veterinaria de Tandil. Provincia de Buenos Aires. Gobernación. Comision de Investigaciones Científicas. Centro de Investigación Veterinaria de Tandil; ArgentinaFil: Bottini, Enriqueta. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil. Centro de Investigación Veterinaria de Tandil. Universidad Nacional del Centro de la Provincia de Buenos Aires. Centro de Investigación Veterinaria de Tandil. Provincia de Buenos Aires. Gobernación. Comision de Investigaciones Científicas. Centro de Investigación Veterinaria de Tandil; ArgentinaFil: Cacciato, Claudio Santiago. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil. Centro de Investigación Veterinaria de Tandil. Universidad Nacional del Centro de la Provincia de Buenos Aires. Centro de Investigación Veterinaria de Tandil. Provincia de Buenos Aires. Gobernación. Comision de Investigaciones Científicas. Centro de Investigación Veterinaria de Tandil; ArgentinaFil: Monteavaro, Cristina Esther. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil. Centro de Investigación Veterinaria de Tandil. Universidad Nacional del Centro de la Provincia de Buenos Aires. Centro de Investigación Veterinaria de Tandil. Provincia de Buenos Aires. Gobernación. Comision de Investigaciones Científicas. Centro de Investigación Veterinaria de Tandil; ArgentinaFil: Sanso, Andrea Mariel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil. Centro de Investigación Veterinaria de Tandil. Universidad Nacional del Centro de la Provincia de Buenos Aires. Centro de Investigación Veterinaria de Tandil. Provincia de Buenos Aires. Gobernación. Comision de Investigaciones Científicas. Centro de Investigación Veterinaria de Tandil; ArgentinaFil: Bustamante, Ana Victoria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil. Centro de Investigación Veterinaria de Tandil. Universidad Nacional del Centro de la Provincia de Buenos Aires. Centro de Investigación Veterinaria de Tandil. Provincia de Buenos Aires. Gobernación. Comision de Investigaciones Científicas. Centro de Investigación Veterinaria de Tandil; ArgentinaVIII Congreso de la Sociedad Argentina de Bacteriología, Micología y Parasitología Clínica; II Jornada de Micología Clínica y I Jornada de Parasitología ClínicaBuenos AiresArgentinaSociedad Argentina de Bacteriología, Micología y Parasitología Clínic
