Flavored waters: influence of ingredients on antioxidant capacity and terpenoid profile by HS-SPME/GC-MS

The antioxidant profiles of 39 water samples (29 flavored waters based on 10 natural waters) and 6 flavors used in their formulation (furnished by producers) were determined. Total phenol and flavonoid contents, reducing power, and DPPH radical scavenging activity were the optical techniques implemented and included in the referred profile. Flavor extracts were analyzed by HS-SPME/GC-MS to obtain the qualitative and quantitative profiles of the volatile fraction of essential oils. Results pointed out a higher reducing power (0.14 11.8 mg of gallic acid/L) and radical scavenging activity (0.29 211.5 mg Trolox/L) of flavored waters compared with the corresponding natural ones, an interesting fact concerning human health. Bioactive compounds, such as polyphenols, were present in all samples (0.5 359 mg of gallic acid/L), whereas flavonoids were not present either in flavored waters or in flavors. The major components of flavor extracts were monoterpenes, such as citral, R-limonene, carveol, and R-terpineol.

Electrocatalytic evaluation of DNA damage by superoxide radical for antioxidant capacity assessment

The integrity of DNA purine bases was herein used to evaluate the antioxidant capacity. Unlike other DNA-based antioxidant sensors reported so far, the damaging agent chosen was the O 2 radical enzymatically generated by the xanthine/xanthine oxidase system. An adenine-rich oligonucleotide was adsorbed on carbon paste electrodes and subjected to radical damage in the presence/absence of several antioxidant compounds. As a result, partial damage on DNA was observed. A minor product of the radical oxidation was identified by cyclic voltammetry as a diimine adenine derivative also formed during the electrochemical oxidation of adenine/guanine bases. The protective efficiency of several antioxidant compounds was evaluated after electrochemical oxidation of the remaining unoxidized adenine bases, by measuring the electrocatalytic current of NADH mediated by the adsorbed catalyst species generated. A comparison between O 2 and OH radicals as a source of DNA lesions and the scavenging efficiency of various antioxidant compounds against both of them is discussed. Finally, the antioxidant capacity of beverages was evaluated and compared with the results obtained with an optical method.

Evaluation of the total antioxidant capacity of flavored water and electrochemical purine damage by sulfate radicals using a purine-based sensor

In this study, a method for the electrochemical quantification of the total antioxidant capacity (TAC) in beverages was developed. The method is based on the oxidative damage to the purine bases, adenine or guanine, that are immobilized on a glassy carbon electrode (GCE) surface. The oxidative lesions on the DNA bases were promoted by the sulfate radical generated by the persulfate/iron(II) system. The presence of antioxidants on the reactive system promoted the protection of the DNA bases immobilized on the GCE by scavenging the sulfate radical. Square-wave voltammetry (SWV) was the electrochemical technique used to perform this study. The efficiencies of five antioxidants (ascorbic acid, gallic acid, caffeic acid, coumaric acid and resveratrol) in scavenging the sulfate radical and, therefore, their ability to protect the purine bases immobilized on the GCE were investigated. These results demonstrated that the purine-based biosensor is suitable for the rapid assessment of the TAC in flavors and flavored water.

Towards a reliable technology for antioxidant capacity and oxidative damage evaluation: Electrochemical (bio)sensors

To counteract and prevent the deleterious effect of free radicals the living organisms have developed complex endogenous and exogenous antioxidant systems. Several analytical methodologies have been proposed in order to quantify antioxidants in food, beverages and biological fluids. This paper revises the electroanalytical approaches developed for the assessment of the total or individual antioxidant capacity. Four electrochemical sensing approaches have been identified, based on the direct electrochemical detection of antioxidant at bare or chemically modified electrodes, and using enzymatic and DNA-based biosensors.

Control and comparison of the antioxidant capacity of beers

The purpose of the present work is to determine the antioxidant capacity (AC) of 27 commercial beers. The AC indicates the degree of protection of a certain organism against oxidative damage provoked by reactive oxygen and nitrogen species. Assays were carried out by the following methods: (i) total radical trapping antioxidant parameter (TRAP); (ii) trolox equivalent antioxidant capacity (TEAC); (iii) trolox equivalent antioxidant capacity (DPPH); (iv) ferric-ion reducing antioxidant parameter (FRAP); (v) cupric reducing antioxidant capacity (CUPRAC); (vi) oxygen radical absorbance capacity (ORAC). Ascorbic acid (AA), gallic acid (GA) and trolox (TR) were used as standards. All beers showed antioxidant power, but a wide range of ACs was observed. The effect of several factors upon these differences was studied. Statistical differences were found between ACs of beers of different colours. ORAC method provided always higher experimental ACs, of significant statistical differences to other assays.

Enterprises' internationalisation strategy: skills in exportation and customs law

Economical development has always been connected to the commercial exchanges between people, due to the necessity to suppress their needs. With the increasing growth of international business and more competitive and demanding markets, exportation has become an important first step to internationalisation. Unlike what happened in the past, companies must be aware that the enrolment in the current global market is risky and requires elaborated technical procedures. Internationalisation should not be treated as an isolated event of business management. The first part of this paper aims to understand the export process and fit it in the current stage of international trade, keeping in mind the framework of export under the customs law. Then, we tried to understand how Portuguese companies should face this process in their internationalisation strategy, and what skills organisations must acquire to be able to export competitively in the current scenario of globalisation. The investigation was based on interviews in companies that, through a process of internationalisation by exportation, have implemented themselves strongly in extern markets. This investigation allowed us to analyse the companies’ motivations to become international, as well as the selection criteria for the export destinations. It was also possible to identify the main obstacles to the internationalisation of Portuguese companies. We concluded that companies that choose exportation as a way to become international acquire specific skills that enable them to become competitive in international trade. However, studies have failed to answer the second initial question about whether the measures implemented by Customs potentiate exports.

Cleanup of industrial effluents containing heavy metals: a new opportunity of valorising the biomass produced by brewing industry

Heavy metal pollution is a matter of concern in industrialised countries. Contrary to organic pollutants, heavy metals are not metabolically degraded. This fact has two main consequences: its bioremediation requires another strategy and heavy metals can be indefinitely recycled. Yeast cells of Saccharomyces cerevisiae are produced at high amounts as a by-product of brewing industry constituting a cheap raw material. In the present work, the possibility of valorising this type of biomass in the bioremediation of real industrial effluents containing heavy metals is reviewed. Given the autoaggregation capacity (flocculation) of brewing yeast cells, a fast and off-cost yeast separation is achieved after the treatment of metal-laden effluent, which reduces the costs associated with the process. This is a critical issue when we are looking for an effective, eco-friendly, and low-cost technology. The possibility of the bioremediation of industrial effluents linked with the selective recovery of metals, in a strategy of simultaneous minimisation of environmental hazard of industrial wastes with financial benefits from reselling or recycling the metals, is discussed.

Capacity sharing and stealing in serverbased real-time systems

A dynamic scheduler that supports the coexistence of guaranteed and non-guaranteed bandwidth servers is proposed. Overloads are handled by an efficient reclaiming of residual capacities originated by early completions as well as by allowing reserved capacity stealing of non-guaranteed bandwidth servers. The proposed dynamic budget accounting mechanism ensures that at a particular time the currently executing server is using a residual capacity, its own capacity or is stealing some reserved capacity, eliminating the need of additional server states or unbounded queues. The server to which the budget accounting is going to be performed is dynamically determined at the time instant when a capacity is needed. This paper describes and evaluates the proposed scheduling algorithm, showing that it can efficiently reduce the mean tardiness of periodic jobs. The achieved results become even more significant when tasks’ computation times have a large variance.

Estratégias de investimento em mercados liberalizados de energia elétrica

Dissertação para obtenção do grau de Mestre em Engenharia Electrotécnica Ramo Energia

Differences of absorptive capacity between firms within a cluster

Firms located within a cluster have access to tacit, complex and specific local knowledge which allow them to develop competitive advantage. However, firms have no equal ability to access and to apply that knowledge, meaning that not all have a similar knowledge absorptive capacity. Using a sample of the largest Portuguese firms within a footwear cluster, this paper examine whether there are significant differences in firm’s absorptive capacity and whether such differences within a cluster are related to firms’ specific characteristics. The results suggest that absorptive capacity is significantly associated with the firms’ characteristics, namely size, export intensity and position within the cluster.

Professional and community satisfaction with the Brazilian family health strategy

OBJECTIVE: To analyze the strengths and limitations of the Family Health Strategy from the perspective of health care professionals and the community. METHODS: Between June-August 2009, in the city of Vespasiano, Minas Gerais State, Southeastern Brazil, a questionnaire was used to evaluate the Family Health Strategy (ESF) with 77 healthcare professionals and 293 caregivers of children under five. Health care professional training, community access to health care, communication with patients and delivery of health education and pediatric care were the main points of interest in the evaluation. Logistic regression analysis was used to obtain odds ratios and 95% confidence intervals as well as to assess the statistical significance of the variables studied. RESULTS: The majority of health care professionals reported their program training was insufficient in quantity, content and method of delivery. Caregivers and professionals identified similar weaknesses (services not accessible to the community, lack of healthcare professionals, poor training for professionals) and strengths (community health worker-patient communications, provision of educational information, and pediatric care). Recommendations for improvement included: more doctors and specialists, more and better training, and scheduling improvements. Caregiver satisfaction with the ESF was found to be related to perceived benefits such as community health agent household visits (OR 5.8, 95%CI 2.8;12.1), good professional-patient relationships (OR 4.8, 95%CI 2.5;9.3), and family-focused health (OR 4.1, 95%CI 1.6;10.2); and perceived problems such as lack of personnel (OR 0.3, 95%CI 0.2;0.6), difficulty with access (OR 0.2, 95%CI 0.1;0.4), and poor quality of care (OR 0.3, 95%CI 0.1;0.6). Overall, 62% of caregivers reported being generally satisfied with the ESF services. CONCLUSIONS: Identifying the limitations and strengths of the Family Health Strategy from the healthcare professional and caregiver perspective may serve to advance primary community healthcare in Brazil.

On the capacity of cluster-tree ZigBee networks

Modeling the fundamental performance limits of Wireless Sensor Networks (WSNs) is of paramount importance to understand their behavior under worst-case conditions and to make the appropriate design choices. In that direction this paper contributes with an analytical methodology for modeling cluster-tree WSNs where the data sink can either be static or mobile. We assess the validity and pessimism of analytical model by comparing the worst-case results with the values measured through an experimental test-bed based on Commercial-Off- The-Shelf (COTS) technologies, namely TelosB motes running TinyOS.

Capacity sharing and stealing in dynamic server-based real-time systems

This paper proposes a dynamic scheduler that supports the coexistence of guaranteed and non-guaranteed bandwidth servers to efficiently handle soft-tasks’ overloads by making additional capacity available from two sources: (i) residual capacity allocated but unused when jobs complete in less than their budgeted execution time; (ii) stealing capacity from inactive non-isolated servers used to schedule best-effort jobs. The effectiveness of the proposed approach in reducing the mean tardiness of periodic jobs is demonstrated through extensive simulations. The achieved results become even more significant when tasks’ computation times have a large variance.

The quest for a balanced manpower capacity: different flexibility strategies examined

To cope with permanent fluctuations in demand, organizations are challenged to organize their manpower capacity in a flexible way. Different strategies of manpower planning are being used for this purpose. Using data from the 2002 Panel Survey of Organisations Flanders, we first verify to what extent temporal, contractual and functional flexibility strategies are applied in Flemish organizations. Subsequently, logistic regression is used to analyse the link between these flexible work strategies and a ‘fitting manpower capacity’. While the results show a negative association between the use of temporal or contractual flexibility measures and a balanced manpower capacity, functional flexibility seems to be positively related. The different logics in which numerical and functional flexibility proceed can be labeled as ‘curative’ versus ‘preventive’ strategies of flexibility. Further analyses discern between various interpretations of functional flexibility and assess whether different team types make a contribution to a fitting manpower capacity.

Does 6-minutes walk test predict functional capacity in elderly people?

Portugal has an accentuated aging tendency, presenting an elderly population (individuals with more than 65 years old) of 19.2%. The average life expectancy is 79.2 years. Thus, it’s important to maintain autonomy and independency as long as possible. Functional ability concept rises from the need to evaluate the capacity to conduct daily activities in an independent way. It can be estimated with the 6-minute walk test (6MWT) and other validated test. This test is simple, reliable, valid and consists in a daily activity (walk). The goals of this study was to verify associations between functional capacity measured with two different instruments (6MWT and Composite Physical Function (CPF) scale) and between those results and characterization variables.