885 research outputs found
Experimental validation of a fully-adaptive smart antenna prototype
The architecture of a fully-adaptive smart antenna working in the 2.4 GHz band is described and its functionalities preliminarily assessed. The radiating unity consists of an eight-element linear array of dipoles with a finite reflecting plane. The adaptive behaviour is achieved by means of a set of electronically-driven vector modulators that realise the array weights. The capability to react in real-time to complex interference scenarios is provided by an SW control module based on the particle swarm optimiser (PSO) algorithm. To assess the effectiveness of such an implementation, a selected set of results is reported and discussed. This paper is a postprint of a paper submitted to and accepted for publication in Electronics Letters and is subject to Institution of Engineering and Technology Copyright. The copy of record is available at IET Digital Library
Automatic implantable cardioverter defibrillator pocket infection due to Providencia rettgeri: a case report
Coagulase-negative staphylococci and Staphylococcus aureus are the commonest pathogens involved in infections of pacemaker-defibrillator systems. Among causative Gram-negative bacteria, infections due to Klebsiella, Serratia, Pseudomonas, Acinetobacter and other species have been reported. We report herein a unique case of an automatic implantable cardioverter defibrillator infection due to Providencia rettgeri in a 65-year-old male who was admitted to our service with bacteremia and infection of the generator and subcutaneous array in a recently implanted device
A Comparison Between Deterministic and Stochastic Inversions of Phaseless Data for Microwave Imaging
The development of microwave imaging techniques and their application are strongly related to the possibility to realize fast and cheap measurement systems. On the contrary, the phase acquisition usually requires complex and expensive apparatus and it turns out to be critical especially at high frequencies. Moreover, holographic and interferometric methods, often used in optical applications [1], are usually characterized by a high computational burden because of the time‐consuming data post‐processing. Consequently, the study of efficient algorithms for the reconstruction from amplitude‐only data is necessary in several applications. Also published in: Progress In Electromagnetics Research Symposium Abstracts, Hangzhou, China, March 24-28, 200
Expression of a Hyperthermophilic Cellobiohydrolase in Transgenic Nicotiana tabacum by Protein Storage Vacuole Targeting
Abstract Plant expression of microbial Cell Wall Degrading Enzymes (CWDEs) is a valuable strategy to produce industrial enzymes at affordable cost. Unfortunately, the constitutive expression of CWDEs may affect plant fitness to variable extents, including developmental alterations, sterility and even lethality. In order to explore novel strategies for expressing CWDEs in crops, the cellobiohydrolase CBM3GH5, from the hyperthermophilic bacterium Caldicellulosiruptor saccharolyticus, was constitutively expressed in N. tabacum by targeting the enzyme both to the apoplast and to the protein storage vacuole. The apoplast targeting failed to isolate plants expressing the recombinant enzyme despite a large number of transformants being screened. On the opposite side, the targeting of the cellobiohydrolase to the protein storage vacuole led to several transgenic lines expressing CBM3GH5, with an enzyme yield of up to 0.08 mg g DW 121 (1.67 Units g DW 121) in the mature leaf tissue. The analysis of CBM3GH5 activity revealed that the enzyme accumulated in different plant organs in a developmental-dependent manner, with the highest abundance in mature leaves and roots, followed by seeds, stems and leaf ribs. Notably, both leaves and stems from transgenic plants were characterized by an improved temperature-dependent saccharification profile. View Full-Tex
Dampening the DAMPs: how plants maintain the homeostasis of cell wall molecular patterns and avoid hyper-immunity
Several oligosaccharide fragments derived from plant cell walls activate plant immunity and behave as typical damage-associated molecular patterns (DAMPs). Some of them also behave as negative regulators of growth and development, and due to their antithetic effect on immunity and growth, their concentrations, activity, time of formation, and localization is critical for the so-called “growth-defense trade-off.” Moreover, like in animals, over accumulation of DAMPs in plants provokes deleterious physiological effects and may cause hyper-immunity if the cellular mechanisms controlling their homeostasis fail. Recently, a mechanism has been discovered that controls the activity of two well-known plant DAMPs, oligogalacturonides (OGs), released upon hydrolysis of homogalacturonan (HG), and cellodextrins (CDs), products of cellulose breakdown. The potential homeostatic mechanism involves specific oxidases belonging to the family of berberine bridge enzyme-like (BBE-like) proteins. Oxidation of OGs and CDs not only inactivates their DAMP activity, but also makes them a significantly less desirable food source for microbial pathogens. The evidence that oxidation and inactivation of OGs and CDs may be a general strategy of plants for controlling the homeostasis of DAMPs is discussed. The possibility exists of discovering additional oxidative and/or inactivating enzymes targeting other DAMP molecules both in the plant and in animal kingdoms
Isolation and characterization of oxidizedoligogalacturonides: meccanism of dampening of damps
Oligogalacturonides (OGs) released upon partial degradation of homogalacturonan, are a
well-known class of Damage-Associated Molecular Patterns (DAMPs). Besides inducing immunity,
OGs negatively affect plant growth by antagonizing auxin responses.
Because the recognition of DAMPs poses the intrinsic risk of activating an exaggerated
response that may impair plant survival, dampening mechanisms of DAMPs should exist.
Transgenic Arabidopsis plants (OGM plants) expressing a chimeric protein called "OGmachine"
accumulate oligogalacturonides (OGs) in their tissues and exhibit enhanced resistance to
a variety of pathogens; however the growth of these plants is severely impaired. The prolonged
release of OGs triggers defense responses that in the long term are deleterious for the plant.
We used the OGM plants as a tool to investigate a possible regulatory mechanism by
searching for elicitor-inactive OGs that may derive from elicitor-active OGs through an enzymatic
modification.
By analyzing the OGs produced in the transgenic plants, modified OGs were isolated. The
nature of the modification was investigated by electrospray ionization mass spectrometry and
resulted to be the oxidation to galactaric acid of the residue at the reducing end of OGs (oxOGs).
OxOGs were tested for their ability to induce defense responses and antagonize auxin responses. In
all experiments, they were inactive as compared to the corresponding typical OGs.
We succeeded to isolate and characterize one of the enzymes that causes the inactivation of
OGs: it is a FAD binding oxidase, that we named OGOX1, capable of producing elicitor-inactive
oxidized OGs and H2O2
Imaginários sobre a Frontera Norte no discurso da imprensa nacional argentina
Este artículo estudia los imaginarios asociados a la frontera norte de laArgentina en el discurso de su prensa nacional durante la transición presidencialentre el kirchnerismo, de ideología nacional-popular, y el macrismo, conservadorneoliberal(2015-2016). En el norte, la Argentina comparte fronteras internacionalescon todos sus países limítrofes: toda la frontera con Bolivia, Paraguay y Brasil, yparte con Uruguay y Chile. Sin embargo, la denominación frontera norte no haalcanzado mayor precisión en el discurso académico y oficial. Pese a ello, en eldiscurso periodístico se fue asociando empíricamente, con frecuencia, a la fronterainternacional que la Argentina comparte con Bolivia y Paraguay. Se aplicó un análisiscrítico de discurso a 47 artículos periodísticos que mencionan la frontera norte dela Argentina publicados en La Nación, de línea editorial conservadora, y Página/12,de línea editorial progresista, diarios de circulación nacional con base en el centropolítico-administrativo del país, la Ciudad Autónoma de Buenos Aires. Los resultadosmuestran que estos difieren en el tratamiento del tema, consistentemente con susrespectivas líneas editoriales, aunque coinciden en representar a la frontera nortede la Argentina como un territorio lejano, degradado y desfavorecido.This paper studies the imaginaries attached to the Northern border of Argentina in the discourse of its national press during the presidential transition between Kirchnerism, of national-popular ideology, and conservative-neoliberal Macrism (2015-2016). In the north, Argentina shares international borders with all its neighboring countries: the entire border with Bolivia, Paraguay and Brazil, and part of the border with Uruguay and Chile. However, the name northern border has not been precisely defined in the academic or official discourse. Despite this, in journalistic discourse it has often been empirically associated with the international border that Argentina shares with Bolivia and Paraguay. A critical discourse analysis was applied to 47 journalistic articles that mention the Northern border of Argentina, published in La Nación (conservative) and Página/12 (progressive), national newspapers based in the political-administrative center of the country, the Autonomous City of Buenos Aires. The results show that there are differences in the treatment of the subject, consistent with their respective editorial lines, although they coincide in representing the Northern border of Argentina as a distant, degraded and disadvantaged territory.Este artigo estuda os imaginários associados à Frontera Norte da Argentina no discurso da imprensa nacional daquele país durante a transição presidencial entre o kirchnerismo, da ideologia nacional-popular, e o macrismo, conservadorneoliberal (2015-2016). No norte, a Argentina compartilha fronteiras internacionais com todos seus países limítrofes: toda a fronteira com a Bolívia, o Paraguai e o Brasil e parte da fronteira com o Uruguai e o Chile. No entanto, o nome Frontera Norte não alcançou maior precisão no discurso acadêmico e oficial. Apesar disso, no discurso jornalístico foi associando-se empiricamente, com frequência, à fronteira internacional que a Argentina compartilha com a Bolívia e o Paraguai. Uma análise crítica do discurso foi aplicada em 47 artigos jornalísticos que mencionam a fronteira norte da Argentina publicados no La Nación, de linha editorial conservadora, e o Página/12, de linha editorial progressista, jornais de circulação nacional baseados no centro político-administrativo do país, a Cidade Autônoma de Buenos Aires. Os resultados mostram que estes jornais apresentam diferenças no tratamento do tema, consistentemente nas suas respetivas linhas editoriais, ainda que coincidem em representar à Frontera Norte da Argentina como um território afastado, degradado e desfavorecido.Fil: Navarro Conticello, José Manuel. Universidad de Talca; ChileFil: Benedetti, Alejandro. Universidad de Buenos Aires. Facultad de Filosofía y Letras. Instituto de Geografía "Romualdo Ardissone"; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin
Standardization of inducer-activated broad host range expression modules: debugging and refactoring an alkane-responsive AlkS/PalkB device
Although inducible heterologous expression systems have been available since the birth of recombinant DNA technology, the diversity
of genetic devices and their coming together in the corresponding vectors often result in a lack of reproducibility and interoperability. In
an effort to increase the predictability of expression of genes of interest in a variety of possible bacterial hosts, we propose a composition
standard for debugging and reassembling all regulatory parts that participate in the performance of such devices. As a case study, we
addressed the n-octane and dicyclopropyl ketone-inducible PalkB promoter of the alkane biodegradation pOCT plasmid of Pseudomonas
putida. The standardized expression module included an edited alkS transcription factor divergently expressed and separated from
PalkB by a synthetic buffer segment. The DNA sequence of the alkS gene was modified to alleviate the catabolite repression exerted
by several carbon and nitrogen sources through the Crc/Hfq complex of some hosts. The PalkB promoter and the alkS variants were
then formatted as Standard European Vector Architecture cargoes, and their activity in P. putida was quantified with fluorescent and
luminescent reporters. Despite considerable editing of the DNA sequences involved, the thereby refactored module basically kept the
functioning parameters of the original configuration. The same qualities were inspected when the system was passed to Escherichia
coli and Pseudomonas aeruginosa. We argue that the application of the compositional standard thereby implemented in the AlkS/PalkB
module to other promoter/regulator pairs will enable more complex genetic programming in non-model bacteria.MADONNA H2020-FET OPEN-RIA-2017-1-766975BioRoboost H2020-NMBP-BIO-CSA 2018-820699SynBio4Flav H2020-NMBP-TR-IND/H2020-NMBP BIO-2018-814650MIX-UP H2020-BIO-CN-2019-87029
Hydraulic Safety Evaluation and Dynamic Investigations of Baghetto Bridge in Italy
The present study deals with the structural safety evaluation of a 50-year-old river bridge, called Baghetto Bridge, located in north Italy on the Adda River. Generally speaking, hydraulic processes are the main cause of bridge failure. Scour and hydrodynamic loads have been largely studied by the hydraulic engineering community; however, in practice, integration with structural analysis is often missing. The aim of this research is to provide a multidisciplinary procedure based on hydraulic and dynamic investigations devoted to the structural verification and monitoring of river bridges with traditional mechanical bearings. The deck-river interaction is addressed, studying the influence of debris accumulation on the bridge and performing structural verification of the bearing supports. The actions exerted on the bridge deck by the river current were estimated following the recommendations of the Italian code and making some further assumptions. In addition, dynamic investigations and FE modelling were performed. The results show (1) a relatively fast procedure that can be applied by practitioners to perform structural verification of river bridges with traditional mechanical bearings, and (2) an investigation method to evaluate temperature-frequency correlation as a reference for future inspections
Estilos de liderazgo y su influencia en la satisfacción laboral en los colaboradores de las empresas de construcción de Lima, 2022
Considerando la gran importancia que tiene para los cargos gerenciales el estilo de liderazgo a aplicar en sus colaboradores, la presente investigación pretende analizar la relación entre los estilos de liderazgo y la satisfacción laboral de los colaboradores de las empresas de construcción de Lima. La presente tesis es de tipo correlacional, de corte transversal y diseño no experimental, es decir, no manipulará las variables. La población estuvo constituida por 828 empresas de construcción ubicadas en Lima y los 109 286 colaboradores que la componen. Al aplicar la técnica de muestreo probabilístico aleatorio simple se seleccionó una muestra de 227 empresas y 383 colaboradores. Para medir el grado de correlación de las variables se utilizó el coeficiente de Pearson y el valor obtenido fue de 0,975 y el nivel de significación fue de 0,000<0,05, lo que significa que se rechazó la hipótesis nula y se aceptó la hipótesis alternativa propuesta, lo que confirma que el estilo de liderazgo está relacionado con la satisfacción laboral entre los trabajadores de la industria de la construcción de Lima Metropolitana en Quito. Se concluye que, entre más apropiado sea el estilo de liderazgo, mejores van a ser los niveles de satisfacción laboral, además se comprobó que los estilos de liderazgo democrático y timonel son los estilos que elevan los niveles de satisfacción de los colaboradores de las empresas de construcción en Lima.Considering the great importance for management positions of the leadership style to be applied to their collaborators, this research aims to analyze the relationship between leadership styles and job satisfaction of the collaborators of construction companies in Lima. The present thesis is of a correlational, cross-sectional and non-experimental design, that is, it will not manipulate the variables. The population consisted of 828 construction companies located in Lima and 109,286 employees. By applying the simple random probability sampling technique, a sample of 227 companies and 383 employees was selected. To measure the degree of correlation of the variables, Pearson's coefficient was used and the value obtained was 0.975 and the level of significance was 0.000<0.05, which means that the null hypothesis was rejected and the proposed alternative hypothesis was accepted, confirming that leadership style is related to job satisfaction among workers in the construction industry of Metropolitan Lima in Quito. It is concluded that the more appropriate the leadership style is, the better the levels of job satisfaction will be, and it was also proved that democratic and helmsman leadership styles are the styles that increase the levels of satisfaction of the collaborators of the construction companies in Lima.Tesi
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