Magnetic phases evolution in the LaMn1-xFexO3+y system

We have investigated the crystal structure and magnetic properties for polycrystalline samples of LaMn1-xFexO3+y, in the whole range x=0.0 to x=1.0, prepared by solid state reaction in air. All samples show the ORT-2 orthorhombic structure that suppresses the Jahn-Teller distortion, thus favoring a ferromagnetic (FM) superexchange (SE) interaction between Mn^{3+}-O-Mn^{3+}. For x=0.0 the oxygen excess (y ~ 0.09) produces vacancies in the La and Mn sites and generates a fraction around 18% of Mn^{4+} ions and 82% of the usual Mn^{3+} ions, with possible double exchange interaction between them. The Fe doping in this system is known to produce only stable Fe^{3+} ions. We find an evolution from a fairly strong FM phase with a Curie temperature T_{C} ~ 160 K, for x=0.0, to an antiferromagnetic (AFM) phase with T_{N} = 790 K, for x=1.0, accompanied by clear signatures of a cluster-glass behavior. For intermediate Fe contents a mixed-phase state occurs, with a gradual decrease (increase) of the FM (AFM) phase, accompanied by a systematic transition broadening for 0.2 < x < 0.7. A model based on the expected exchange interaction among the various magnetic-ion types, accounts very well for the saturation-magnetization dependence on Fe doping.Comment: 27 pages, 9 figure

Buyer-seller conflict and cooperation in marketing channels: port wine distribution

The main purpose of this study is to research buyer-seller conflict and cooperation in distribution channels. Based on a multidimensional case study, eight research hypotheses were formulated. Some quantitative research was conducted, based on a questionnaire sent to 101 port wine producers and distribution companies (61 answered properly – 31 producers and 29 distributors – which gave the authors a 60% rate of response, considered to be very good for these types of studies; those 101 port wine producers and distributors initially chosen were the most important in Europe, considering the volume of production and sales, and constituting, for that reason, a convenience sample). A binary probit model was developed to analyze the data. The results of the study demonstrate that when conflict is ongoing and intense it prevents the development of cooperative relationships. A trustworthy company is more likely to solve conflicts. When trust and adaptation capabilities increase, so does potential cooperation. The results also show that the presence of a foreign sales representative in the team does not exert a negative influence on cooperation. Finally, cooperation can be considered as an important means of developing skills and resources, which can then be applied to existing transaction relationships

Biochemical assessment of oxidative stress by the use of açai (Euterpe oleracea Martius) gel in physically active individuals.

Abstract The relation between oxidative stress and inflammation induced by diseases and exercise has increased the interest in the benefits of antioxidant supplements in the improvement of health and physical and mental performance. The aim of this study was to evaluate the effectiveness of açai gel in reducing oxidative stress in individuals engaged in physical activities as well as their acceptance. Sensory evaluation was performed to determine its acceptability and the biochemical parameters related to immune profile and biomarkers of muscle, liver and oxidative stress, with and without the use of gel were evaluated. The appearance, sweetness and overall impression of the açai gel were considered good. It was observed a significant increase in CK enzyme, without the gel as well as the oxidative stress biomarkers, it was observed that the MDA (with and without gel) a significant increase (p < 0.05). Through biochemical evaluation, it is concluded that the gel provided protection for some of parameters studied, since it modulated the immunological parameter reducing the lymphocyte activity and muscular stress. However, more studies must be carried out with a larger number of individuals to confirm the gel functionality

Bioaccessibility of provitamin A carotenoids in orange-fleshed pumpkins using the coupled In vitro digestion/ Caco-2 cell model.

The aim of this study was to evaluate the effects of cooking styles on the bioacessibility of BC in pumpkin