Expressions for the g-Drazin inverse of additive perturbed elements in a Banach algebra

AbstractWe study additive properties of the g-Drazin inverse in a Banach algebra A. In our development we derive a representation of the resolvent of a 2×2 matrix with entries in A, which is then used to find explicit expressions for the g-Drazin inverse of the sum a+b, under new conditions on a,b∈A. As an application of our results we obtain a representation for the Drazin inverse of a 2×2 complex block matrix in terms of the individual blocks, under certain conditions

Three-operator problems in Banach spaces

ABSTRACT: We study the analogue of 3-space problems for classes of operators acting on Banach spaces. We show examples of classes of operators having or failing the 3-operator property, and give several methods to obtain classes with this property.The research of the first author was supported in part by Project IB16056 de la Junta de Extremadura; that of the first and third authors was supported in part by MINECO (Spain), Project MTM2016-76958. This paper benefited from a stay in 2016 of Castillo and González at Kanagawa University invited by Prof. Cho

Expanding the role of FurA as essential global regulator in cyanobacteria

In the nitrogen-fixing heterocyst-forming cyanobacterium Anabaena sp. PCC 7120, the ferric uptake regulator FurA plays a global regulatory role. Failures to eliminate wild-type copies of furA gene from the polyploid genome suggest essential functions. In the present study, we developed a selectively regulated furA expression system by the replacement of furA promoter in the Anabaena sp. chromosomes with the Co2+/Zn2+ inducible coaT promoter from Synechocystis sp. PCC 6803. By removing Co2+ and Zn2+ from the medium and shutting off furA expression, we showed that FurA was absolutely required for cyanobacterial growth. RNA-seq based comparative transcriptome analyses of the furA-turning off strain and its parental wild-type in conjunction with subsequent electrophoretic mobility shift assays and semi-quantitative RT-PCR were carried out in order to identify direct transcriptional targets and unravel new biological roles of FurA. The results of such approaches led us to identify 15 novel direct iron-dependent transcriptional targets belonging to different functional categories including detoxification and defences against oxidative stress, phycobilisome degradation, chlorophyll catabolism and programmed cell death, light sensing and response, heterocyst differentiation, exopolysaccharide biosynthesis, among others. Our analyses evidence novel interactions in the complex regulatory network orchestrated by FurA in cyanobacteria

Classes of operators preserved by extensions or liftings

A standard way to obtain extensions (resp. liftings) of operators is by making the so-called operations of push-out (resp. pull-back). In this paper we study the preservation of some classes of operators associated with an operator ideal Aunder push-out extensions or pull-back liftings. We show several examples of classical operator ideals whose associated classes are preserved, we prove that the preservation of those classes under push-out extension or pull-back lifting implies that the space ideal of Asatisfies the 3-space property, and we derive some results for Athat are useful in the study of commutative diagrams of operators.that of the three authors has been supported in part by MINECO (Spain), Project MTM2016-76958

Modeling Internet as a User-Adapted Speech Service

Proceedings of: 7th International Conference, HAIS 2012, Salamanca, Spain, March 28-30th, 2012.The web has become the largest repository of multimedia information and its convergence with telecommunications is now bringing the benefits of web technology and hybrid artificial intelligence systems to hand-held devices. However, maximizing accessibility is not always the main objective in the design of web applications, specially if it is concerned with facilitating access for disabled people. This way, natural spoken conversation and multimodal conversational agents have been proposed as a solution to facilitate a more natural interaction with these kind of devices. In this paper, we describe a proposal to provide spoken access to Internet information that is valid not only to generate basic applications (e.g., web search engines), but also to develop dialog-based speech interfaces that facilitate a user-adapted access that enhances web services. We describe our proposal and detail several applications developed to provide evidences about the benefits of introducing speech to make the enormous web content accessible to all mobile phone users.Research funded by projects CICYT TIN2011-28620- C02-01, CICYT TEC2011-28626-C02-02,CAM CONTEXTS (S2009/TIC-1485), and DPS2008-07029-C02-02.Publicad

Microwave-assisted extraction of lycopene in tomato peels: effect of extraction conditions on all-trans and cis- isomer yields

Lycopene is the primary carotenoid in tomato peels, a processing byproduct, and can be used as a natural color or bioactive ingredient. Unfortunately, extractions are inefficient as lycopene is extremely nonpolar and susceptible to degradation. As a rapid technique, microwave-assisted extraction (MAE) potentially offers efficient lycopene recovery. Thus, the objectives of this research were to: 1) optimize MAE of lycopene from tomato peels and 2) evaluate the effect of treatment on all-trans and isomer yields. Response surface methodology (RSM) was employed to optimize lycopene extraction with solvent ratio solid-liquid ratios, microwave power, and delivered energy equivalents as factors. High performance liquid chromatography with a diode array detector (HPLC-DAD) was used for isomer separation and quantification. Optimum MAE conditions were determined as: 0:10 solvent ratio at 400 W with a yield of 13.592 mg/100 g of extracted all-trans-lycopene. RSM suggested that ethyl acetate was a better MAE solvent for lycopene recovery as compared to hexane, which overall extracted less lycopene. HPLC-DAD indicated that MAE significantly improved all-trans and total lycopene yields, while conventional extraction demonstrated higher proportions of cis-isomer yields. Additionally, electron micrographs showed that significant structural disruption occurred in MAE-treated samples, possibly allowing for the improved lycopene extraction

El pulpeo com etanol como alternativa para incrementar la competitividade de fábricas de papel mediante su desarrollo prospectivo integrado a industrias de la caña de azúcar

La industria de la pulpa y el papel para ondular en el contexto internacional y nacional presenta debelidades tecnológicas en su proceso que afectan negativamente al medio ambiente, esto unido a las fuertes regulaciones ambientales que se han impuesto a las industrias de processos químicos obligan a los productores a buscar soluciones para hacer sus processos ambientalmente más eficientes. El proyecto está dirigido a lograr una tecnología ambientalmente compatible y económicamente competitiva de producción de papeles para ondular, para ello se parte de los beneficios que la integración material y energética de los produtos derivados de la caña de azúcar puede lograr

Mushrooms extracts and compounds in cosmetics, cosmeceuticals and nutricosmetics—a review

The cosmetic industry is constantly in search of ingredients from natural sources because of their competitive effectiveness and lower toxicity effects. Mushrooms have been an important part of our diet for years and are now finding their way as cosmetic ingredients, either as cosmeceutical or as nutricosmetics. The present review focuses on the most relevant activities of mushroom extracts, as well as on their bioactive compounds, which make them interesting ingredients for cosmetic formulations. Mushroom extracts, as well as their bioactive metabolites, revealed anti-tyrosinase, anti-hyaluronidase, anti-collagenase and anti-elastase activity. Emphasis was also given to their important anti-oxidant, antimicrobial and anti-inflammatory potential, topics largely studied by numerous authors, making them very versatile and multi-functional cosmetic ingredients. Some of the bioactive compounds and the mechanism responsible for the activities ascribed to mushrooms were highlighted. Other activities were identified as needing to be further studied in order to identify the major compounds contributing to the target activity, as well as their mechanisms of action. Based on the above findings, mushroom extracts, as well as their bioactive metabolites, constitute important ingredients that can help to combat aging, reduce the severity of inflammatory skin disease and correct hyperpigmentation disorders. These findings and claims must be correctly supported by clinical trials and in vivo studies.The authors acknowledge FCT (Portugal) for financial support to CIMO (PEst-OE/AGUI0690/2015) and to FCT/MEC and FEDER under Programme PT2020 for financial support to LSRE (Project UID/EQU/50020/2013), and to QREN, ON2 and FEDER (Projects NORTE-07-0124-FEDER-000014 and NORTE-07-0162-FEDER-000050)

The Hodge--Poincar\'e polynomial of the moduli spaces of stable vector bundles over an algebraic curve

Let X be a nonsingular complex projective variety that is acted on by a reductive group $G$ and such that $X^{ss} \neq X_{(0)}^{s}\neq \emptyset$. We give formulae for the Hodge--Poincar\'e series of the quotient $X_{(0)}^s/G$. We use these computations to obtain the corresponding formulae for the Hodge--Poincar\'e polynomial of the moduli space of properly stable vector bundles when the rank and the degree are not coprime. We compute explicitly the case in which the rank equals 2 and the degree is even.Comment: Final published version. arXiv admin note: text overlap with arXiv:math/0305346, arXiv:math/0305347 by other author