Noether's Symmetry Theorem for Variational and Optimal Control Problems with Time Delay

We extend the DuBois-Reymond necessary optimality condition and Noether's symmetry theorem to the time delay variational setting. Both Lagrangian and Hamiltonian versions of Noether's theorem are proved, covering problems of the calculus of variations and optimal control with delays.Comment: This is a preprint of a paper whose final and definite form will appear in the international journal Numerical Algebra, Control and Optimization (NACO). Paper accepted for publication 15-March-201

Layer-by-layer deposition of antimicrobial polymers on cellulosic fibers : a new strategy to develop bioactive textiles

In recent years, there has been an increase of infectious diseases caused by different microorganisms and the development of antibiotic resistance. In this way, the search for new and efficient antibacterial materials is imperative. The main polysaccharides currently used in the biomedical and pharmaceutical domains are chitin and its derivative chitosan (CH) and alginates (ALG). In this study, a simple technique of Layer by Layer (LbL) of applying polycation CH and polyanion ALG was used to prepare CH/ALG multilayers on cotton samples via the electrostatic assembly with success. The CH/ALG cotton samples (functionalized) were investigated for their antibacterial properties towards Staphylococcus aureus and Klebsiella pneumonia using the international standard method JIS L 1902:2002. The antibacterial activity of the functionalized samples was tested in terms of bacteriostatic and bactericidal activity, and results showed that the samples exhibited a bacteriostatic effect on the two bacteria tested, as expected. In addition, samples with five layers (CH/ALG/CH/ALG/CH) were more effective in inhibiting bacterial growth. This new coating for cellulosic fibers is a new strategy and may open new avenues for the development of antimicrobial polymers with potential application in health-care field.The authors would like to thank Fundacao para a Ciencia e Tecnologia (FCT) for the funding granted concerning the project - PTDC/EBB-BIO/113671/2009 (FCOMP-01-0124-FEDER-014752) Skin2Tex. Also, we would like to thank Fundo Europeu de Desenvolvimento Regional (FEDER) through COMPETE - Programa Operacional Factores de Competitividade (POFC) for the co-funding

Cost-Effectiveness of the 13-Valent Pneumococcal Conjugate Vaccine in Children in Portugal

Pneumococcal infections are the leading cause of vaccine-preventable death in children. In June 2015, the 13-valent pneumococcal conjugate vaccine (PCV13) was introduced in the Portuguese Immunization Program. We evaluated the cost-effectiveness of children vaccinated with PCV13 versus no vaccination for preventing pneumococcal diseases.info:eu-repo/semantics/publishedVersio

Corporate brand identity in higher education: a relational perspective

Identity is traditionally defined as an emission concept (Kapferer, 2008). Yet, some research points out that there are external factors that that can influence it (Kennedy, 1975; Markwick e Fill, 1997; Balmer e Gray, 2000). This subject is even more interesting if one considers corporate brands. According to Aaker (2004) the number, the power and the credibility of corporate associations are bigger in the case corporate brands. Literature recognizes the influence of relationships between companies in identity management (Hakansson and Snehota, 1989, 1995; Hakansson and Ford, 2002). Yet, given the increasingly important role of corporate brands, it is surprising that to date no attempt to evaluate that influence has been made in corporate brand´s identity management and reputation. Also Keller and Lehman (2006) highlight relationships and costumer experience as two areas requiring more investigation. The authors argue that corporate brand´s identity can be developed under a relational perspective using relationships with other recognised brands in order to generate positive reputations in stakeholders. Based in relationship and corporate brand identity management, a framework is developed to identify how corporate brands select, develop and invest in relationships with other brands. The context of the proposed relationship concept is the services area (Dwyer et al, 1987; Moorman et al, 1992; Rauyruen et al, 2005 and Hennig-Thurau and Klee, 1997). An empirical qualitative research is designed using two reputational technological higher education institutions (two corporate brands) acting in Portuguese public higher education market.info:eu-repo/semantics/publishedVersio

Principais clostridioses dos ovinos e caprinos: sinais clínicos e medidas preventivas.

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Mathematical retroreflectors

Retroreflectors are optical devices that reverse the direction of incident beams of light. Here we present a collection of billiard type retroreflectors consisting of four objects; three of them are asymptotically perfect retroreflectors, and the fourth one is a retroreflector which is very close to perfect. Three objects of the collection have recently been discovered and published or submitted for publication. The fourth object - notched angle - is a new one; a proof of its retroreflectivity is given.Comment: 32 pages, 19 figure

Timing and prediction of CO2 eruptions from Crystal Geyser, UT

Special instruments were deployed at Crystal Geyser, Utah, in August 2005 creating a contiguous 76-day record of eruptions from this cold geyser. Sensors measured temperature and fluid movement at the base of the geyser. Analysis of the time series that contains the start time and duration of 140 eruptions reveals a striking bimodal distribution in eruption duration. About two thirds of the eruptions were short (7-32 min), and about one third were long (98-113 min). No eruption lasted between 32 and 98 min. There is a strong correlation between the duration of an eruption and the subsequent time until the next eruption. A linear least-squares fit of these data can be used to predict the time of the next eruption. The predictions were within one hour of actual eruption time for 90% of the very short eruptions (7-19 min), and about 45% of the long eruptions. Combined with emission estimates from a previous study, we estimate the annual CO{sub 2} emission from Crystal Geyser to be about 11 gigagrams (11,000 tons)