Fermionic wave functions and Grassmann fields as possible sources of dark energy

We study a cosmological model with a fermionic field which can be interpreted as a source of dark energy in the universe. Two different approaches were considered, the first one with a massless fermionic field represented by a standard wave-function and the second one where a massive field is a Grassmann variable. {The first case naturally reduces to a XCDM model with a constant equation of state parameter, while the last case reproduces a $w(z)$CDM model for a massive field}, and in the massless limit, the intrinsic grassmannian property of the field leads always to a vacuum equation of state parameter, irrespective the specific form of the potential. Both cases leads to a dark energy contribution of the fermionic sector. The models are totally compatible with recent cosmological data from Supernovae, BAO and Hubble parameter measurements. A brief study of linear evolution of density perturbations shows that some of the small scale problems related to standard model can be at least alleviated.Comment: 21 pages, 5 figures, final version publishe

Microcalorimeter as a Biologic Activity Monitor for the Study of \u3cem\u3eBrachiaria Brizantha\u3c/em\u3e Seed Germination Process

Calorimetry helps better understanding of biological processes (Calvet & Prat, 1963). Very sensitive thermal sensors and microcalorimeters allow real time investigation and monitoring heat production of seed germination but few experiments have been performed in this area (Sigstad & Prado, 1999). Moreover, experimental procedures correlating germination phenomena and chemical thermodynamics are exceptional (Barboza, 2002). One can detect calorimetrically the heat flow produced during seed germination and compare the results with data recorded using standard germination methodology (ISTA, 1985). Seed germination and the biomass increase respiration and determination of the energy involved aids understanding of the energetic cycle involved. This work analysed the germination of Brachiaria brizantha seeds, including the water uptake phase

Optimization of the precipitation of clavulanic acid from fermented broth using t-octylamine as intermediate

This work describes the use of clavulanic acid (CA) precipitation as the final step in the process of purification of CA from fermentation broth as an alternative to conventional methods employed traditionally. The purpose of this study was to use a stable intermediate (t-octylamine) between the conversion of CA to its salt form (potassium clavulanate), thereby enabling the resulting intermediate (amine salt of clavulanic acid) to improve the purification process and maintain the stability of the resulting potassium clavulanate. To this end, response surface methodology was employed to optimize the precipitation step. For the first reaction, five temperatures (6.6 to 23.4 ºC), concentrations of clavulanic acid in organic solvent (6.6 to 23.4 mg/mL) and t-octylamine inflow rates (0.33 to 1.17 drop/min) were selected based on a central composite rotatable design (CCRD). For the second reaction, five temperatures (11.6 to 28.4 ºC), concentrations of clavulanic acid amine salt in organic solvent (8.2 to 41.8 mg/mL) and concentrations of potassium 2-ethylhexanoate (0.2 to 1.2 molar) were also selected using CCRD. From these results, precipitation conditions were selected and applied to the purification of CA from the fermentation broth, obtaining a yield of 72.37%.23124

Cardioprotective Properties Of Aerobic And Resistance Training Against Myocardial Infarction

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)We evaluated the effects of aerobic and resistance exercise training on ventricular morphometry and function, physical capacity, autonomic function, as well as on ventricular inflammatory status in trained rats prior to myocardial infarction. Male Wistar rats were divided into the following groups: sedentary+Sham, sedentary+myocardial infarction, aerobic trained+myocardial infarction, and resistance trained+myocardial infarction. Sham and myocardial infarction were performed after training periods. In the days following the surgeries, evaluations were performed. Aerobic training prevents aerobic (to a greater extent) and resistance capacity impairments, ventricular dysfunction, baroreflex sensitivity and autonomic disorders (vagal tonus decrease and sympathetic tonus increase) triggered by myocardial infarction. Resistance training was able to prevent negative changes to aerobic and resistance capacity (to a greater extent) but not to ventricular dysfunction, and it prevented cardiovascular sympathetic increments. Additionally, both types of training reduced left ventricle inflammatory cytokine concentration. Our results suggest that aerobic and, for the first time, dynamic resistance training were able to reduce sympathetic tonus to the heart and vessels, as well as preventing the increase in pro-inflammatory cytokine concentrations in the left ventricle of trained groups. These data emphasizes the positive effects of aerobic and dynamic resistance training on the prevention of the negative changes triggered by myocardial infarction.376421430Fundacao de Amparo a Pesquisa do Estado de Sao Paulo, Brazil [FAPESP - 2013/14788-9, FAPESP - 2014/06669-2]Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP