A sufficient optimality condition for delayed state-linear optimal control problems

We give answer to an open question by proving a sufficient optimality condition for state-linear optimal control problems with time delays in state and control variables. In the proof of our main result, we transform a delayed state-linear optimal control problem to an equivalent non-delayed problem. This allows us to use a well-known theorem that ensures a sufficient optimality condition for non-delayed state-linear optimal control problems. An example is given in order to illustrate the obtained result.Comment: This is a preprint of a paper whose final and definite form is with 'Discrete and Continuous Dynamical Systems -- Series B' (DCDS-B), ISSN 1531-3492, eISSN 1553-524X, available at [http://www.aimsciences.org/journal/1531-3492]. Paper Submitted 31/Dec/2017; Revised 13/April/2018; Accepted 11/Jan/201

An integrative assessment to determine the genotoxic hazard of estuarine sediments: combining cell and whole-organism responses

The application of the Comet assay in environmental monitoring remains challenging in face of the complexity of environmental stressors, e.g., when dealing with estuarine sediments, that hampers the drawing of cause-effect relationships. Although the in vitro Comet assay may circumvent confounding factors, its application in environmental risk assessment (ERA) still needs validation. As such, the present work aims at integrating genotoxicity and oxidative DNA damage induced by sediment-bound toxicants in HepG2 cells with oxidative stress-related effects observed in three species collected from an impacted estuary. Distinct patterns were observed in cells exposed to crude mixtures of sediment contaminants from the urban/industrial area comparatively to the ones from the rural/riverine area of the estuary, with respect to oxidative DNA damage and oxidative DNA damage. The extracts obtained with the most polar solvent and the crude extracts caused the most significant oxidative DNA damage in HepG2 cells, as measured by the formamidopyrimidine-DNA glycosylase (FPG)-modified Comet assay. This observation suggests that metals and unknown toxicants more hydrophilic than polycyclic aromatic hydrocarbons may be important causative agents, especially in samples from the rural part of the estuary, where oxidative DNA damage was the most significant. Clams, sole, and cuttlefish responded differentially to environmental agents triggering oxidative stress, albeit yielding results accordant with the oxidative DNA damage observed in HepG2 cells. Overall, the integration of in vivo biomarker responses and Comet assay data in HepG2 cells yielded a comparable pattern, indicating that the in vitro FPG-modified Comet assay may be an effective and complementary line-of-evidence in ERA even in particularly challenging, natural, scenarios such as estuarine environments

O património pré-histórico da Póvoa de Lanhoso. Que valorização?

"Cadernos do Noroeste. Série História 3". Vol. 1/2 (2003)Este texto, apresentado nas Primeiras Jornadas do Património do concelho da Póvoa de Lanhoso, em Março de 2000, está dividido em três partes. A primeira, analisa alguns aspectos de natureza social e política que contribuíram para destruição de parte significativa do património pré-histórico nacional e, consequentemente, do concelho da Póvoa de Lanhoso. A segunda, dá conta do estado actual da investigação arqueológica relativa ao período em causa, naquele concelho e a terceira, enuncia algumas reflexões conducentes à defesa e valorização do património pré-histórico conhecido.Cet article, présenté au "Primeiras Jornadas do Património" de la petite ville de Póvoa de Lanhoso, au mois de Mars 2000, comporte trois parties. La première, est conscrée à l'analyse de quelques aspects à caractère social et politique ayant contribué à la destruction d'une grande partie du patrimoine archéologique de la Préhistoire au niveau nacional et local. La deuxième, traite de l'état actuel des investigations archéologiques concernant la période étudiée pour cette ville. Enfin, la troisième partie annonce quelques reflexions visant à développer une stratégie de défense et de valorisation du patrimoine préhistorique déjà connu.We presented this paper, for the first time, on the "Primeiras Jornadas do Património", at Póvoa de Lanhoso, in March 2000. At the follow paper we begin to analise some social and policial aspects we think that could be related with the destruction of some prehistoric monuments all over our country, as well as at this region. Next we try to give a general idea on nowadays archaeological research concerning the prehistoric local human occupation. We finish with some reflections in order to preserve and to promote the local prehistoric heritage.info:eu-repo/semantics/publishedVersio

Global analysis of the sugarcane microtranscriptome reveals a unique composition of small RNAs associated with axillary bud outgrowth

Axillary bud outgrowth determines shoot architecture and is under the control of endogenous hormones and a fine-tuned gene-expression network, which probably includes small RNAs (sRNAs). Although it is well known that sRNAs act broadly in plant development, our understanding about their roles in vegetative bud outgrowth remains limited. Moreover, the expression profiles of microRNAs (miRNAs) and their targets within axillary buds are largely unknown. Here, we employed sRNA next-generation sequencing as well as computational and gene-expression analysis to identify and quantify sRNAs and their targets in vegetative axillary buds of the biofuel crop sugarcane (Saccharum spp.). Computational analysis allowed the identification of 26 conserved miRNA families and two putative novel miRNAs, as well as a number of trans-acting small interfering RNAs. sRNAs associated with transposable elements and protein-encoding genes were similarly represented in both inactive and developing bud libraries. Conversely, sequencing and quantitative reverse transcription-PCR results revealed that specific miRNAs were differentially expressed in developing buds, and some correlated negatively with the expression of their targets at specific stages of axillary bud development. For instance, the expression patterns of miR159 and its target GAMYB suggested that they may play roles in regulating abscisic acid-signalling pathways during sugarcane bud outgrowth. Our work reveals, for the first time, differences in the composition and expression profiles of diverse sRNAs and targets between inactive and developing vegetative buds that, together with the endogenous balance of specific hormones, may be important in regulating axillary bud outgrowth

Fijación de nitrógeno en ajipa (Pachyrhizus ahipa (Wedd.) Parodi) inoculada con distintas cepas de Rhizobium spp.

18 páginas.-- 2 figuras.-- 18 referencias.-- 5 tablas.-- Memoria del XXXVII Curso Internacional de Edafología y Biología VegetalDirector: Leidi, Eduardo O.Entre las leguminosas tropicales con raíces tuberosas comestibles, como Apio, Pachyrhizus, Pediomelum y Vigna, la jícama (yam bean), que corresponde a Pachyrhizus (L.) Urban, es la única especie cultivada, con difusión en América Central (México, Guatemala, El Salvador, Honduras) y en Asia (China, Tailandia, Sumatra, etc.) (Serensen, 1996). Un pariente cercano a la jícama, la ajipa (Pachyrhizus ahipa (Wedd.) Parodi) fue cultivada en el periodo precolombino por los Incas, y su importancia en la actualidad es muy reducida permaneciendo en cultivos aislados en valles andinos entre 1500 y 2500 m de altura sobre el nivel del mar en Bolivia, Pení, y Norte de Argentina (Serensen, 1996). Las culturas indígenas han sido particularmente eficientes para domesticar especies tuberosas comestibles. Además de la papa, la mandioca o la batata difundidas por todo el mundo, existen otras como la oca (Oxalis tuberosa) o el ulluco (Ullucus tuberosus) que aún hoy ocupan miles de hectáreas en los Andes, desde Venezuela y Colombia hasta Argentina y Chile pero también existen algunas especies que han quedado relegadas y hasta con riesgo de desaparecer. Entre ellas se cuenta la ajipa o ahipa (Pachyrhizus ahipa (Wedd.) Parodi), una leguminosas como muchas otras especies comestibles comunes en nuestra dieta (guisante, judía, haba, soja, etc.). El género de la ajipa posee una serie de especies con propiedades similares: la ya mencionada jícama (P. erosus) cultivada en México y en varios países del sudeste asiático y el jacatupe '(P. tuberosus) cultivado principalmente en ciertos sectores de la cuenca amazónica.Beca AECI, Realizado dentro del proyecto AHIPA FAIR6-CT98-4297Peer reviewe

Un panista opina sobre su partido

Entrevista hecha por Ana María Silva a Felipe Vicencio Álvarez, senador por el estado de Jalisco de la LIX Legislatura del Congreso de la Unión, por el Partido Acción Nacional (PAN). En ella plantea las estrategias que tendría que llevar a cabo su partido para realizar su proyecto social, económico y político.ITESO, A.C

A multistage stochastic approach for the optimal bidding of variable renewable energy in the day-ahead, intraday and balancing markets

ABSTRACT: Market agents with renewable resources face amplified uncertainty when forecasting energy production to securely place bids in electricity markets. To deal with uncertainties, stochastic modelling has been applied to optimize the bidding strategy of these market agents. However, studies found in the literature usually focus on day-ahead and balancing markets, leaving aside intraday markets that could be used to correct bidding positions as uncertainty gets resolved. This paper proposes a multistage stochastic decision-aid algorithm based on linear programming to optimize the bidding strategy of market agents in three different electricity markets -day-ahead, intraday, and balance markets. The market agent represents a Virtual Power Plant with wind, solar PV, and storage technologies, and its participation in three electricity markets was compared to the participation in DA and BM markets only. Results show that participating in all three markets increased the profit achieved by the VPP agent by 10.1% while also decreasing the incurred imbalances by 63.8%. The results demonstrate that having accurate tools to deal with the multi-settlement framework of electricity markets while considering the uncertainties of daily operations is key to a successful integration of renewable energy resources into electricity markets and power systems.info:eu-repo/semantics/publishedVersio

Supplier selection and procurement in SMEs: Insights from the literature on key criteria and purchasing strategies

Effective strategic purchasing and supplier selection in companies provides businesses with leverage in acquiring goods and services. Thus, companies are in a better position to negotiate prices, discounts, delivery times and logistic channels. Also, strategic purchasing allows for performing a risk assessment to ensure the company's profitability. This research aimed to identify the key currently deliberated by SMEs for supplier selection, considering such purchasing strategies as (1) cost reduction, (2) risk management, (3) global sourcing, (4) total quality management, (5) sustainable management and (6) supplier management. Also, it aimed to identify the emerging issues related to purchasing strategies. This research work performed a content analysis following a literature review. The Scopus indexation database was selected to conduct the document search. After the refinement process, based on 59 analysed documents, bibliometric assessment tools were applied to identify the key criteria for supplier selection. The TOP6 highest ranked criteria, which corresponds to 80 % of the most referred criteria, include: (1) the quality of goods; (2) compliance with the delivery times; (3) price/cost; (4) supplier reputation and/or market positioning; (5) geographical location; and (6) supplier performance history. The goal of strategic purchasing is to support the companies in achieving long-term goals through its integration into the company's strategic planning process. It should be identified by the managers as an important resource. Several factors elevate the importance of strategic purchasing, namely, environmental protection, technology advances related to logistics 4.0, and risk assessment related to global sourcing and sustainability. The present research is in line with the findings of the referred literature, i.e., the application of prioritised criteria for the procurement and supplier selection operations in the industrial context, aiming to reduce lead times and logistic costs. The criteria must be aligned w- (undefined