Symbolic Computation of Variational Symmetries in Optimal Control

We use a computer algebra system to compute, in an efficient way, optimal control variational symmetries up to a gauge term. The symmetries are then used to obtain families of Noether's first integrals, possibly in the presence of nonconservative external forces. As an application, we obtain eight independent first integrals for the sub-Riemannian nilpotent problem (2,3,5,8).Comment: Presented at the 4th Junior European Meeting on "Control and Optimization", Bialystok Technical University, Bialystok, Poland, 11-14 September 2005. Accepted (24-Feb-2006) to Control & Cybernetic

Perceptions in Living Kidney Donation: What ProtagonistsThink and Feel

Abstract Background Although donor perceptions of donation have been evaluated in several programs, evaluation of associated recipients has not been as frequent. Purpose Our aim was to evaluate and compare after transplantation, donor and recipient perceptions of donation. Methods After transplantation 35 recipients and 45 donors completed a sociodemographic and a donation perception questionnaire. We applied the Fisher test to descriptive (absolute and relative frequency) data. Results 57.8% of donors were female and 62.9% of recipients male. 53.3% of donors were siblings, 44.5% parents, and 2.2% a daughter. Most recipients (71.9%) thought that the donation was the donors' initiative and 21.9% that it was suggested by medical team. 96.4% responded that it was the donor's wish that determined their decision; 51.4% had serious or some doubts about accepting the option, but for 48.6% it was an easy decision. Among the donors, 88.9% decided by themselves and 8.9% were asked for donation. For 91.1%, their wish was the main reason of the decision, but 8.9% felt a moral obligation; 77.8% thought it was an easy decision, and 17.8% hesitated a little 84.4% were not worried about their future health. Conclusions Altruistic motivations were predominant in both groups. Most recipients thought that the motivation for donation was self-determined, a finding that agreed with donor perceptions. Perceptions about the quality of and changes in emotional relationship were the same in both groups. Donors and recipients referred to the donation process as positive, but there were some negative emotions and perceptions

Depression and anxiety in living kidney donation: evaluation of donors and recipients.

Transplant Proc. 2011 Jan-Feb;43(1):131-6. Depression and anxiety in living kidney donation: evaluation of donors and recipients. Lopes A, Frade IC, Teixeira L, Oliveira C, Almeida M, Dias L, Henriques AC. SourceLyaison-Psychiatry and Health Psychology Unit, Oporto Hospital Centre, Oporto, Portugal. [email protected] Abstract BACKGROUND: Psychosocial status of donors before and after living kidney donor transplantation has been an important concern. Investigations of psychosocial issues in related recipients are not frequent. AIM: The aims of this study were to evaluate and compare psychopathologic dimensions in donors and recipients before and after transplantation. METHODS: Thirty-five recipients and 45 donors completed a psychosocial evaluation before and after transplantation. We applied Pearson chi-square, McNemar, Fisher, Wilcoxon, and Mann-Whitney tests as well as linear and logistic regression statistical methods. RESULTS: Before transplantation 100% of the recipients presented total anxiety, compared with 64.4% of donors, with higher anxiety levels in all dimensions (P < .001). Also, 38.7% of recipients and 16.3% of donors had moderate/serious depression (P = .029). Men showed higher levels of cognitive anxiety before transplantation (odds ratio [OR] = 4.3; P = .008). After versus before transplantation central nervous system and cognitive anxiety had diminished in recipients (P = .031; P = .035, respectively); there were higher levels of cognitive anxiety than among the donors (P = .007). Depression showed no significant changes in recipients or donors; the differences were no longer significant. There were less severely depressed recipients but an increase among severely depressed donors. Male recipients and donors showed greater cognitive anxiety (P = .02; P = .04, respectively) at both times. Female recipients presented with more severe depression (P = .036). CONCLUSIONS: Anxiety is an important symptom. Surgery had a positive impact to lower anxiety in recipients. Most protagonists displayed little or no depression; it was more prevalent among recipients. Donors and recipients maintained some psychopathologic symptoms after surgery. We defined vulnerable groups among these cohorts. Copyright © 2011 Elsevier Inc. All rights reserved

Application of Landsat images for quantifying the energy balance under conditions of land use changes in the Semi-Arid region of Brazil.

In the Nilo Coelho irrigation scheme, Brazil, the natural vegetation has been replaced by irrigated agriculture, bringing importance for the quantification of the effects on the energy exchanges between the mixed vegetated surfaces and the lower atmosphere. Landsat satellite images and agro-meteorological stations from 1992 to 2011 were used together, for modelling these exchanges. Surface albedo (0), NDVI and surface temperature (T0) were the basic remote sensing retrieving parameters necessary to calculate the latent heat flux E) and the surface resistance to evapotranspiration (rs) on a large scale. The daily net radiation (Rn) was obtained from 0, air temperature (Ta) and short-wave transmissivity (sw) throughout the slob equation, allowing the quantification of the daily sensible heat flux (H) by residual in the energy balance equation. With a threshold value for rs, it was possible to separate the energy fluxes from crops and natural vegetation. The averaged fractions of Rn partitioned as H and E, were in average 39 and 67%, respectively. It was observed an increase of the energy used for the evapotranspiration process inside irrigated areas from 51% in 1992 to 80% in 2011, with the ratio E/Rn presenting an increase of 3 % per year. The tools and models applied in the current research, can subsidize the monitoring of the coupled climate and land use changes effects in irrigation perimeters, being valuable when aiming the sustainability of the irrigated agriculture in the future, avoiding conflicts among different water users

Effect of hydrodynamic conditions and bulk substrate concentration on biofilm efficiency at steady-state

Water and wastewater biofilm reactors work under quite different substrate concentrations and hydrodynamic conditions. It is important to analyse how these factors can affect the activity of biofilms. The work reported here presents results obtained with biofilms formed by Pseudomonas fluorescens suspensions carried out at different conditions: low and high fluid velocities; low and high bulk substrate concentrations

In vitro tests of suitability of bacteriocin-producing lactic acid bacteria, as potential biopreservation cultures in vacuum-packaged cold-smoked salmon

The objectives of this study were to ascertain the in vitro potential of nine bacteriocin-producing lactic acid bacteria (LAB) strains, isolated from vacuum-packaged cold-smoked salmon (CSS), for possible use as biopreservative cultures against Listeria monocytogenes. The antilisterial activity of cultures’ supernatants was assessed at 0.5%, 3.0% and 5.0% w/v of salt, at 5ºC, 10ºC and 25ºC both in aerobic and anaerobic atmospheres, simulating the conditions pertaining in vacuum-packaged CSS. The kinetics of growth, bacteriocin biosynthesis, the minimum inhibitory concentrations (MICs) of ten antibiotics, histamine and tyramine production of LAB strains, were determined jointly with the haemolytic activity for the enterococci. Only five strains were able to secrete active bacteriocins into the culture medium, at high salt concentrations and low temperatures, both in aerobic and anaerobic atmospheres. Enterococci showed neither haemolyt ic activity nor vancomycin resistance. The production of histamine was not observed for any of the bacteriocin-producing strains

LEARNING HOW TO WORK IN THE ARTS FIELD IN PORTUGAL: A BIOGRAPHICAL APPROACH TO THE MIGRANT ARTISTS’ TRAJECTORIES

The article considers the key dimensions of the life trajectories of the immigrant artists living in the Lisbon metropolitan area focusing on those related to the socialization process both in formal institutions and in a broader setting of informal learning. The authors conducted a sociological analysis of 20 biographical interviews with a heterogeneous set of individuals, including musicians, dancers and plastic artists. These interviews were a part of the research project on the social trajectories of migrant artists from the non-European Union countries living in Portugal. The results of the analysis show that formal and informal learning together with the migrant experience are intertwined and constitute the key factor in the configuration of migrant trajectories. There is often a mobility pattern across art styles, which makes differences between formal and informal circumstances in the life trajectories of migrant artists evident. Migration has a strong impact on the artistic work; this impact affects different areas of biographical experience: contact with the Portuguese culture, development of ethnic references, and participation in transnational art movements. The condition of immigrant artists generally implies a long trajectory of artistic training, including significant experiences of formal and informal learning in multiple social contexts throughout the life course. For those dedicated to the new transnational urban cultures (hip hop, graffiti, etc.), informal learning is the most important element. For those engaged in the traditional arts, the attendance of lengthy artistic programs seems to be a fundamental prerequisite for training and recognition. Together with the long and significant artists’ investments in their education, the sociological study also revealed the great vulnerability (and precariousness) of their life trajectories, and the lack of structures supporting their access to the labor market

A comparative study of techniques for modeling the spatiotemporal distribution of heat and moisture fluxes at different agroecosystems in Brazil.

As a result, this chapter is structured as follows: following the introduction, the study region, datasets, and the steps for modeling are described; one of the first comparisons between SAFER and SEBAL is then made available, comparing estimates by these two modeling approaches against corresponding estimates by the traditional FAO methodology; next, results from case studies are furnished, covering application of both SAFER and SEBAL methods with satellite images, in some irrigation crops and natural vegetation at different spatial and temporal scales in the Brazilian semiarid region

Portuguese nurses’ stress, anxiety, and depression reduction strategies during the COVID-19 outbreak

The COVID-19 pandemic has contributed to mental health problems worldwide. Nurses are particularly prone to stress because they directly care for individuals with suspected or confirmed cases of COVID-19. The aims of this study were (a) to explore the association between the mental health promotion strategies used by nurses during the COVID-19 outbreak and their symptoms of depression, anxiety, and stress; (b) to compare the symptoms of depression, anxiety, and stress of mental health nurses to those of non-mental health nurses; and (c) to compare the frequency of use of mental health strategies of mental health nurses to those of non-mental health nurses. A cross-sectional study was conducted with a sample of 821 nurses. Univariate and multivariate regression models were developed to identify potential protective factors of depression, anxiety, and stress. The chi-square test was also used to compare the use of strategies among mental health and non-mental health nurses. Portuguese nurses demonstrated high symptoms of depressive symptoms, stress, and anxiety. Healthy eating, physical activity, rest between shifts, maintaining social contacts, verbalizing feelings/emotions, and spending less time searching for information about COVID-19 were associated with better mental health. Mental health nurses had less depression, anxiety, and stress, and used more strategies to promote mental health than other nurses. We consider it important to promote nurses’ mental health literacy by encouraging them to develop skills and strategies aimed at improving their resilience and ability to deal with difficult situations while caring for the population.info:eu-repo/semantics/publishedVersio