3,921 research outputs found
Visual Spike-based Convolution Processing with a Cellular Automata Architecture
this paper presents a first approach for
implementations which fuse the Address-Event-Representation
(AER) processing with the Cellular Automata using FPGA and
AER-tools. This new strategy applies spike-based convolution
filters inspired by Cellular Automata for AER vision
processing. Spike-based systems are neuro-inspired circuits
implementations traditionally used for sensory systems or
sensor signal processing. AER is a neuromorphic
communication protocol for transferring asynchronous events
between VLSI spike-based chips. These neuro-inspired
implementations allow developing complex, multilayer,
multichip neuromorphic systems and have been used to design
sensor chips, such as retinas and cochlea, processing chips, e.g.
filters, and learning chips. Furthermore, Cellular Automata is a
bio-inspired processing model for problem solving. This
approach divides the processing synchronous cells which
change their states at the same time in order to get the solution.Ministerio de Educación y Ciencia TEC2006-11730-C03-02Ministerio de Ciencia e Innovación TEC2009-10639-C04-02Junta de Andalucía P06-TIC-0141
Electric and magnetic dipolar response of Germanium spheres: Interference effects, scattering anisotropy and optical forces
We address the scattering cross sections, and their consequences, for
submicrometer Germanium spheres. It is shown that there is a wide window in the
near infrared where light scattering by these particles is fully described by
their induced electric and magnetic dipoles. In this way, we observe remarkable
anisotropic scattering angular distributions, as well as zero forward or
backward scattered intensities, which until recently was theoretically
demonstrated only for hypothetically postulated magnetodielectric spheres.
Also, interesting new effects of the optical forces exerted on these objects
are now obtained.Comment: 13 pages, 4 figure
Redox-dependent and redox-independent functions of Caenorhabditis elegans thioredoxin 1
Thioredoxins (TRX) are traditionally considered as enzymes catalyzing redox reactions. However, redox-independent functions of thioredoxins have been described in different organisms, although the underlying molecular mechanisms are yet unknown. We report here the characterization of the first generated endogenous redox-inactive thioredoxin in an animal model, the TRX-1 in the nematode Caenorhabditis elegans. We find that TRX-1 dually regulates the formation of an endurance larval stage (dauer) by interacting with the insulin pathway in a redox-independent manner and the cGMP pathway in a redox-dependent manner. Moreover, the requirement of TRX-1 for the extended longevity of worms with compromised insulin signalling or under calorie restriction relies on TRX-1 redox activity. In contrast, the nuclear translocation of the SKN-1 transcription factor and increased LIPS-6 protein levels in the intestine upon trx-1 deficiency are strictly redox-independent. Finally, we identify a novel function of C. elegans TRX-1 in male food-leaving behaviour that is redox-dependent. Taken together, our results position C. elegans as an ideal model to gain mechanistic insight into the redox-independent functions of metazoan thioredoxins, overcoming the limitations imposed by the embryonic lethal phenotypes of thioredoxin mutants in higher organisms.NIH Office of Research Infrastructure P40 OD010440Spanish Ministry of Economy and Competitiveness BFU2015- 64408-PFondo Social Europeo BFU2015- 64408-PNational Institute of Allergy and Infectious Diseases of the National Institutes of Health R01AI07640
Environmental transcriptome analysis reveals physiological differences between biofilm and planktonic modes of life of the iron oxidizing bacteria Leptospirillum spp. in their natural microbial community
<p>Abstract</p> <p>Background</p> <p>Extreme acidic environments are characterized by their high metal content and lack of nutrients (oligotrophy). Macroscopic biofilms and filaments usually grow on the water-air interface or under the stream attached to solid substrates (streamers). In the Río Tinto (Spain), brown filaments develop under the water stream where the Gram-negative iron-oxidizing bacteria <it>Leptospirillum </it>spp. (<it>L. ferrooxidans </it>and <it>L. ferriphilum</it>) and <it>Acidithiobacillus ferrooxidans </it>are abundant. These microorganisms play a critical role in bioleaching processes for industrial (biominery) and environmental applications (acid mine drainage, bioremediation). The aim of this study was to investigate the physiological differences between the free living (planktonic) and the sessile (biofilm associated) lifestyles of <it>Leptospirillum </it>spp. as part of its natural extremely acidophilic community.</p> <p>Results</p> <p>Total RNA extracted from environmental samples was used to determine the composition of the metabolically active members of the microbial community and then to compare the biofilm and planktonic environmental transcriptomes by hybridizing to a genomic microarray of <it>L. ferrooxidans</it>. Genes up-regulated in the filamentous biofilm are involved in cellular functions related to biofilm formation and maintenance, such as: motility and quorum sensing (<it>mqsR, cheAY, fliA, motAB</it>), synthesis of cell wall structures (<it>lnt, murA, murB</it>), specific proteases (<it>clpX/clpP</it>), stress response chaperons (<it>clpB, clpC, grpE-dnaKJ, groESL</it>), etc. Additionally, genes involved in mixed acid fermentation (<it>poxB</it>, <it>ackA</it>) were up-regulated in the biofilm. This result, together with the presence of small organic acids like acetate and formate (1.36 mM and 0.06 mM respectively) in the acidic (pH 1.8) water stream, suggests that either <it>L. ferrooxidans </it>or other member of the microbial community are producing acetate in the acidophilic biofilm under microaerophilic conditions.</p> <p>Conclusions</p> <p>Our results indicate that the acidophilic filaments are dynamic structures in which different mechanisms for biofilm formation/dispersion are operating. Specific transcriptomic fingerprints can be inferred for both planktonic and sessile cells, having the former a more active TCA cycle, while the mixed acid fermentation process dominate in the latter. The excretion of acetate may play a relevant ecological role as a source of electron donor for heterotrophic Fe<sup>3+ </sup>reducers like some Alphaproteobacteria, <it>Acidobacterium </it>spp. and <it>Sulfobacillus </it>spp., also present in the biofilm. Additionally, acetate may have a negative effect on bioleaching by inhibiting the growth of chemolithotrophic bacteria.</p
Response to fungal exudates of the rhizosphere isolate Pseudomonas sp. UMAF110 involves a GGDEF/EAL domain-containing protein
Pseudomonas sp. UMAF110, isolated from rhizosphere soil in Spain, display in vitro antagonism towards the pythopathogenic fungus Rosellinia necatrix and is able grow in fungal exudates (BM-RE medium). A transposon mutant library of this strain was constructed and several mutants were selected by their reduced competitiveness in BM-RE medium. Pseudomonas sp. UMAF110-G3, which contains the transposon into a gene encoding a putative REC/PAS/GGDEF/EAL protein, was selected for further characterization. Blastn searches using the sequence of the gene interrupted by the transposon in UMAF110-G3, here called cmpA (c-di-GMP Metabolizing Protein), yielded a single positive hit (98% cover, 78% identity) with a gene from a terpene-degrading Pseudomonas sp. strain isolated from soil. Context analysis of the cmpA gene in Pseudomonas sp. UMAF110 showed that this gene is located downstream from several genes involved in flagellar motility/chemotaxis. RT-PCR experiments further confirmed that cmpA form a transcriptional unit with the che gene cluster. Expression analysis of cmpA by qRT-PCR clearly showed upregulation of this gene after transfer of Pseudomonas sp. UMAF110 cells to BM-RE medium, suggesting a role for this operon in response to fungal exudates. Deletion of cmpA in Pseudomonas sp. UMAF110 did not affect the ability of the strain to form biofilms under the conditions tested. However, overexpression of wild type CmpA in Pseudomonas putida KT2440 negatively regulated biofilm formation in this strain. Together, these results suggest that CmpA could be involved in signal transduction pathways regulating flagellar motility/chemotaxis in response to fungal exudates.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
Escrotal circumference and skin flush sexual in florida male goat
Escrotal circumference (CE) by orquimetry and skin flush sexual (SFS) by observation in the inguino-escrotal skin in four Florida male goats were studied for 14 months. Seasonal variation was observed in CE, that was minor in autumn (30.84±0.24 cm) and maximun in spring (32.79 ±0.22 cm). Also, seasonal pattern was observed in SFS, with pale skin during winter (p<0.001). Light hours and temperature shown significant correlation with CE and SFS.En un grupo de cuatro machos cabríos de raza Florida se estudiaron las variaciones de la circunferencia escrotal (CE) y el grado de hiperemia inguino-escrotal o skin flush sexual (SFS) durante un periodo de 14 meses. Los resultados revelan una ligera variación estacional de la CE que es menor en otoño (30,84 ±0,24 cm.) y máxima en primavera (32,79±0,22 cm). El SFS presentó una distribución estacional, de manera que la coloración inguino-escrotal de la piel era más pálida durante el invierno (p<0,001). Tanto las horas de luz como la temperatura mostraron correlación significativa respecto a la CE y SFS
ADQPCI: Data Acquisition Board for Educational purposes
En este trabajo se presenta una de las placas de adquisición de datos que se ha desarrollado con fines docentes para su utilización en prácticas relacionadas con sistemas en tiempo real e
informática industrial y se plantean algunas de las ventajas e inconvenientes frente a la utilización
de placas comerciales. A lo largo del trabajo se detalla el diseño del hardware, en el que se ha
priorizado la facilidad de programación, siendo ésta una de las ventajas frente a las placas
comerciales. En estas prácticas es fundamental que el alumno tome conciencia de la importancia
de la interfaz hardware-software, si se quiere conseguir un sistema fiable y que explote al máximo
las características del hardware. Con el desarrollo de una placa de adquisición de datos se
consigue un sistema que el alumno puede utilizar en varias asignaturas de su titulación que están
relacionadas con el desarrollo y programación de sistemas empotrados.In this work a data acquisition board developed for educational use in subjects related to real-time
systems and industrial computing, is presented. The main advantages and disadvantages of using
these boards versus the use of commercial boards are discussed. The hardware design described
along this work emphasizes the facility of programming the board, which is one of the main
advantages versus the commercial boards. In these practices it is essential that student
comprehend the importance of the hardware-software interface in order to obtain a reliable system
which exploits in a maximum way the characteristics of the hardware. The development of a data
acquisition board allows to obtain a system that the students can use in several course during his
university career which are related to the development and programming of embedded system
Comportamiento cíclico de una acero St-52-3N: Influencia de los módulos de elasticidad en las estimaciones de vida a fatiga
Dada la dependencia de los módulos de elasticidad en los métodos de estimación de vida a fatiga, se analiza el
comportamiento cíclico y la variación de estos con el grado de deformación. En este estudio se llevan a cabo una serie de
experimentos de fatiga uniaxial en control de deformación, con R=-1, a bajo número de ciclos y a temperatura ambiente,
para caracterizar el comportamiento cíclico del acero al carbono St-52-3N. Se realizaron ensayos de fatiga uniaxial tanto
de tracción como de torsión.
Se compara los valores de los módulos de elasticidad monotónico y cíclico, además de los valores cíclicos
correspondientes a los segmentos de descarga y carga (E1 ,E2) (acordes con ISO/DIS 121106). Se pone de manifiesto la
variabilidad cometida al calcular el incremento de deformación plástica según el Método Estándar de ensayo que
utilicemos (BS/ISO, ASTM, AECMA) y que determinará en cada caso la estimación del módulo de elasticidad cíclicoUniversidad de Málaga. Campus de Excelencia Internacional Andalucía Tec
Identification of plasma and urinary metabolites and catabolites derived from orange juice (poly)phenols: analysis by high-performance liquid chromatography–high-resolution mass spectrometry
Orange juice is a rich source of (poly)phenols, in particular, the flavanones hesperetin-7-O-rutinoside and naringenin-7-O-rutinoside. Following the acute consumption of 500 mL of orange juice containing 398 μmol of (poly)phenols by 12 volunteers, 0–24 h plasma and urine samples were analyzed by targeted high-performance liquid chromatography–high-resolution mass spectrometry in order to identify flavanone metabolites and phenolic acid and aromatic catabolites. A total of 19 flavanone metabolites—comprising di-O-glucuronide, O-glucuronide, O-glucuronyl-sulfate, and sulfate derivatives of hesperetin, naringenin, and eriodictyol—and 65 microbial-derived phenolic catabolites, such as phenylpropanoid, phenylpropionic, phenylacetic, benzoic, and hydroxycarboxylic acids and benzenetriol and benzoylglycine derivatives, including free phenolics and phase II sulfate, glucuronide, and methyl metabolites, were identified or partially identified in plasma and/or urine samples. The data obtained provide a detailed evaluation of the fate of orange juice (poly)phenols as they pass through the gastrointestinal tract and are absorbed into the circulatory system prior to renal excretion. Potential pathways for these conversions are proposed
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