8,331 research outputs found
Design issues and experimental characterization of a continuously-tuned adaptive CMOS LNA
This paper presents the design implementation and experimental characterization of an adaptive Low Noise Amplifier (LNA) intended for multi-standard Radio Frequency (RF) wireless transceivers. The circuit —fabricated in a 90-nm CMOS technology— is a two-stage inductively degenerated common-source topology that combines PMOS varactors with programmable load to make the operation of the circuit continuously tunable. Practical design issues are analyzed, considering the effect of circuit parasitics associated to the chip package and integrated inductors, capacitors and varactors. Experimental measurements show a continuous tuning of NF and Sparameters within the 1.75-2.23GHz band, featuring NF19.6dB and IIP3> −9.8dBm, with a power dissipation < 23mW from a 1-V supply voltage.Ministerio de Ciencia e Innovación (FEDER) TEC2007-67247-C02-01/MICJunta de Andalucía, Consejo Regional de Innovación, ciencia y empresa TIC-253
Assessing the influence of the carbon oxidation-reduction state on organic pollutant biodegradation in algal-bacterial photobioreactors
The influence of the carbon oxidation-reduction state (CORS) of organic pollutants on their biodegradation in enclosed algal-bacterial photobioreactors was evaluated using a consortium of enriched wild-type methanotrophic bacteria and microalgae. Methane, methanol and glucose (with CORS -4, -2 and 0, respectively) were chosen as model organic pollutants. In the absence of external oxygen supply, microalgal photosynthesis was not capable of supporting a significant methane and methanol biodegradation due to their high oxygen demands per carbon unit, while glucose was fully oxidized by photosynthetic oxygenation. When bicarbonate was added, removal efficiencies of 37¿±¿4% (20 days), 65¿±¿4% (11 days) and 100% (2 days) were recorded for CH(4,) CH(3)OH and C(6)H(12)O(6), respectively due to the additional oxygen generated from photosynthetic bicarbonate assimilation. The use of NO(3)(-) instead of NH(4)(+) as nitrogen source (N oxidation-reduction state of +5 vs. -3) resulted in an increase in CH(4) degradation from 0 to 33¿±¿3% in the absence of bicarbonate and from 37¿±¿4% to 100% in the presence of bicarbonate, likely due to a decrease in the stoichiometric oxygen requirements and the higher photosynthetic oxygen production. Hypothetically, the CORS of the substrates might affect the CORS of the microalgal biomass composition (higher lipid content). However, the total lipid content of the algal-bacterial biomass was 19¿±¿7% in the absence and 16¿±¿2% in the presence of bicarbonat
SPIDER X - Environmental effects in central and satellite early-type galaxies through the stellar fossil record
A detailed analysis of how environment affects the star formation history of
early-type galaxies (ETGs) is undertaken via high signal to noise ratio stacked
spectra obtained from a sample of 20,977 ETGs (morphologically selected) from
the SDSS-based SPIDER survey. Two major parameters are considered for the
study: the central velocity dispersion (sigma), which relates to local drivers
of star formation, and the mass of the host halo, which relates to
environment-related effects. In addition, we separate the sample between
centrals (the most massive galaxy in a halo) and satellites. We derive trends
of age, metallicity, and [alpha/Fe] enhancement, with sigma. We confirm that
the major driver of stellar population properties in ETGs is velocity
dispersion, with a second-order effect associated to the central/satellite
nature of the galaxy. No environmental dependence is detected for satellite
ETGs, except at low sigma - where satellites in groups or in the outskirts of
clusters tend to be younger than those in the central regions of clusters. In
contrast, the trends for centrals show a significant dependence on halo mass.
Central ETGs in groups (i.e. with a halo mass >10^12.5 M_Sun) have younger
ages, lower [alpha/Fe], and higher internal reddening, than "isolated" systems
(i.e. centrals residing in low-mass, <10^12.5 M_Sun, halos). Our findings imply
that central ETGs in groups formed their stellar component over longer time
scales than "isolated" centrals, mainly because of gas-rich interactions with
their companion galaxies.Comment: 22 pages, 19 figures, accepted for publication in MNRA
Prevalence of QoI resistance and mtDNA diversity in the Irish Zymoseptoria tritici population
peer-reviewedThe emergence and spread of Quinone outside Inhibitor (QoI) fungicide resistance in the Irish Zymoseptoria tritici population in the early 2000s had immediate impacts on the efficacy of the entire group of fungicides for the control of septoria tritici blotch. As a result, a dramatic reduction in the quantities applied to winter wheat occurred in the following seasons. Even in the absence of these fungicides, the frequency of the resistance allele, G143A in the pathogens mtDNA has remained exceptionally high (>97%), and as such, it can be anticipated that continued poor efficacy of current QoI fungicides will be observed. Amongst the isolates with G143A, differences in sensitivity to the QoI pyraclostrobin were observed in vitro. The addition of the alternative oxidase (AOX) inhibitor salicylhydroxamic acid increased sensitivity in these isolates, suggesting some continued impairment of respiration by the QoI fungicides, albeit weak. Interestingly, amongst those tested, the strains from a site with a high frequency of inserts in the MFS1 transporter gene known to enhance QoI efflux did not exhibit this increase in sensitivity. A total of 19 mtDNA haplotypes were detected amongst the 2017 strain collection. Phylogenetic analysis confirmed the suggestion of a common ancestry of all the haplotypes, even though three of the haplotypes contained at least one sensitive strain
Cancer mortality trends in the Umbria region of Italy 1978–2004: a joinpoint regression analysis
BACKGROUND: The aim of the present paper was to analyse cancer mortality in the Umbria region, from 1978 to 2004. Mortality trends depend on a number of factors including exposures, health system interventions, and possibly artefact (e.g. classification change, variations of data completeness). Descriptive data on mortality only allow for generation of hypotheses to explain observed trends. Some clues on the respective role of possible mortality determinants may be found comparing mortality with incidence and survival data. METHODS: Mortality data for the periods 1978–1993 and 1994–2004 were supplied by the National Institute of Statistics (ISTAT) and the Regional Causes of Death Registry (ReNCaM) respectively. Sex and site-specific mortality time trends were analysed by the "joinpoint regression" method. RESULTS: For all sites combined, in both sexes, the standardised rate was first increasing before the end of the eighties and decreasing thereafter. Gastric cancer mortality showed a different trend by gender; that is the rate constantly decreased over the period among females while, for males, it was first increasing up to 1985 and decreasing thereafter. Liver cancer trend showed a pattern similar to gastric cancer. Large bowel cancer showed a gender specific trend, that is it was increasing among males and stable among females. Also lung cancer mortality varied by gender: it started to decline after 1989 among males but was steadily increasing over the study period among women. A decreasing trend for female breast cancer mortality began in 1994. Prostate cancer mortality trend is the only one showing two significant joinpoints: mortality decreased up to 1990, then it increased up to 1998 and, finally, was decreasing. CONCLUSION: Overall cancer mortality was decreasing in both sexes in Umbria and this favourable trend will probably continue and further improve since population screening against breast, cervix, and large bowel cancers were recently introduced. Besides gastric cancer, tobacco-related cancers and prostate cancer mainly contributed to mortality reduction in males, whereas breast cancer mainly contributed to declining mortality in females
Metapragmática e identidad lingüística: el uso de la función metalingüistica en inmigrantes colombianos en España
Los inmigrantes colombianos en España se encuentran con una variedad distinta de su propia lengua. Este encuentro hace a los hablantes reflexionar sobre el español y su diversidad. Este fenómeno metalingüístico va más allá del concepto de connotation autonymique de Rey-Debove y se debe a la necesidad o el deseo del hablante de intervenir explícita o implícitamente en su discurso y en la interacción. Además, este fenómeno subraya la importancia de la propia variedad lingüística para la creación de una identidad social. El análisis también permite discutir algunos aspectos del metalenguaje partiendo de datos reales. The Colombian immigrants in Spain meet with a different variety of their own language. This finding makes the speakers think about Spanish language and its diversity. This metalinguistic phenomenon goes beyond the connotation autonymique concept by Rey-Debove and it is due to the speaker’s need or desire of planning her discourse and interacting explicitly or implicitly in the communication process. Further, this phenomenon highlights how the own linguistic variety is important by creating a social identity. The analysis also allows to discuss some aspects of metalanguage taking account of real data
Los indios ticuna del alto Amazonas ante los procesos actuales de cambio cultural y globalización.
Los indios ticuna están sujetos en la actualidad a fuerzas de sentidos contrarios aparentemente contradictorio& Por un lado están experimentando un proceso acelerado de aculturación, deculturación e integración a las sociedades nacionales de Brasil, Colombia y Perú a partir del momento de su asentamiento masivo en aldeas a orillas dcl Amazonas. Por otro, el momento presente es tcstigo de una revitalización cultural y política de los ticuna en dirección hacia la autonomia y la defensa de su diferencia cultural. La aparente paradoja descansa en el hecho de que estos segundos procesos han sido puestos en marcha y están posibilitados por las sociedades mayores y los mismos procesos de aculturación. Desde los principios de una Antropologia Aplicada nos proponemos humildemente proponer soluciones al reto al que se enfrenta la diversidad cultural como la que representan los ticuna ante los presentes procesos de cambio diferenciando entre los fenómenos de globalización y aculturación.The contemporary Ticuna lndians are subjected to apparently contradictory forces of opposite senses. On the one hand they undergo an accelerating process of acculturation and integration to the national societies of Brazil, Colombia and 291 E Javier Ullán de la Rosa Los indios ticuna del Alto Amazonas ante los procesos actuales,.. Peru since their settling down in villages by the Amazon riverside. On the other hand, the moment is witnessing a political and cultural reactivation of the Ticuna towards autonomy and the defense of their cultural difference. The apparent paradox lies in the fact that this last trend is been set in motion and enabled by the major societies and the process of acculturation itself. From the principIes of an applied anthropology we humbly aim to propose solutions to the challenge that cultural diversity, as the one represented by the Ticuna, is facing before the present processes of social change by differentiating the phenomenon of globalization from that of acculturation
comparison between thermal energy and acoustic emission for the fatigue behavior of steels
Abstract The paper is focused on the study of fatigue materials, using an energy approach, with the support of two different non-destructive techniques. Indeed, the analysis of the energy behavior was conducted by the simultaneous application of Acoustic Emission (AE) and Thermography (TH). The purpose of the paper was to compare and integrate the results obtained by the two methodologies to assess the fatigue behavior of materials. The experimental tests were carried out on flat steel specimens of steels commonly used for metal carpentry either under static loading or under sequences of increasing cyclic loading. The results allow to define the fatigue limit either by the thermography or by the acoustic emission and they are encouraging to continue the comparison and the integration between the two energetic methodologies
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