Behavior of Peruvian carrot (Arracacia xanthorrhiza) and cassava (Manihot esculenta) starches subjected to the heat-moisture treatment

Peruvian carrot and cassava starches were isolated, adjusted to 30 and 35% moisture, and heatedat 90°C for 8 h. Structural and physicochemical characteristics of the treated starches wereevaluated and compared. High performance anion exchange chromatography with pulsedamperometric detector (HPAEC-PAD), gel permeation chromatography (GPC), and amylosecontent, revealed that the HMT did not change the chemical structures of the starches. A largeagglomeration of granules was observed from SEM, particularly in the Peruvian carrot starch.Crystalline patterns in Peruvian carrot and cassava starches changed from B to C and CAto A,respectively. Relative crystallinity decreased from 30 to 25% in Peruvian Carrot starch, andincreased from 35 to 37% in cassava starch adjusted to 30% moisture. SF and peak viscositydecreased, breakdown was almost completely eliminated (particularly in the Peruvian carrotstarch), and final viscosity increased. WAI and WSI increased as moisture levels of bothstarches increased. Gelatinization temperatures increased and enthalpy decreased. Degrees ofgelatinization increased as the moisture level increased, reaching 33 and 72% in the cassavaand Peruvian carrot starches, respectively. HMT strengthened the intra- and intermolecularinteractions of starches and increased their stability during heating and shearing, but also causeda partial gelatinization in the starches, particularly in Peruvian carrot starch.

Effect of staining agents on color change of composites

Composite resins are materials that can present color changing when exposed to pigments. Objective: The aim of this study was to evaluate, in vitro, the color changing of composites after immersion in different substances for different periods. Material and methods: Two microhybrid composite resins: Charisma (Heraeus – Kulzer) and Opallis (FGM) were used. Red wine and acai pulp were also used as immersion medium. For this study, 32 specimens with 10 mm of diameter and 2 mm of thickness were used, divided into 4 groups: Group 1 – Opallis composite immersed in red wine solution; Group 2 – Opallis composite immersed in acai berry pulp solution; Group 3 – Charisma composite immersed in red wine solution; Group 4 – Charisma composite immersed in acai berry pulp solution. The specimens were evaluated in the following time periods: T0 – baseline, T1 – 24 hours, T2 – 48 hours, T3 – 72 hours and T4 – 96 hours. For the assessment of staining, a spectrophotometer for colorimetry was used (Color Guide 45 / 0, PCB 6807 BYK-Gardner Gerestsried GmBH, Germany), and the values obtained were transferred to a computer and recorded according to CIELAB system. Results: The data were evaluated using Kruskal- Wallis non-parametric tests with the following mean values for the immersion periods of 24, 48, 72 and 96 hours, respectively: G1 – 7.35, 7.84, 9.04,10.48; G2 – 2.92, 4.15, 4.30, 4.64; G3 – 3.14, 7.35, 8.13, 8.43, G4 – 4.49, 5.99, 6.92, 6.76. Conclusion: Red wine showed a higher tendency toward altering the composite color than acai berry pulp. In addition, no significant difference was found concerning to the behavior of the two composite resins. Concerning to the immersion time periods, significant differences were only observed among the groups in the 24 hour time period.

Why medical schools are tolerant of unethical behavior

The exposure to unethical and unprofessional behavior is thought to play a major role in the declining empathy experienced by medical students during their training. We reflect on the reasons why medical schools are tolerant of unethical behavior of faculty. First, there are barriers to reporting unprofessional behavior within medical schools including fear of retaliation and lack of mechanisms to ensure anonymity. Second, deans and directors do not want to look for unethical behavior in their colleagues. Third, most of us have learned to take disrespectful circumstances in health care institutions for granted. Fourth, the accreditation of medical schools around the world does not usually cover the processes or outcomes associated with fostering ethical behavior in students. Several initiatives promise to change that picture.

How can an invasive grass affect fire behavior in a tropical savanna? A community and individual plant level approach

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Effect of glycerol monostearate on the gelatinization behavior of maize starches with different amylose contents

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Anuran skin and basking behavior: the case of the treefrog Bokermannohyla alvarengai (Bokermann, 1956)

We investigated the morphology of the skin and the biochemistry of the lipids in the skin secretion of Bokermannohyla alvarengai, a montane treefrog that is known to bask regularly, motionless in full sunlight for extended periods of time. Our primary goal was to identify structural and biochemical modifications that might assist this frog species to accommodate the conflicting demands for heat exchange and water balance while basking. The modulation of heat exchange in basking B. alvarengai involves changes in skin coloration. We found that this response was supported by a prominent monolayer of large iridophores, whose light reflectance property is adjusted by the response of intervening melanophores. Mucosubstances and lipid compounds, mainly consisted of saturated fatty acids and presumably secreted from granular glands, were detected on the skin of B. alvarengai. These compounds formed an extra-epidermal layer over the animal's dorsal surface that might assist in the prevention of excessive water loss through evaporation. Additionally, we found well-developed skin folds at the ventral region of the frogs that lead to an increment of surface area. This feature combined with the extensive hypervascularization, also noticed for the skin of B. alvarengai, may play an important role in water reabsorption. The suite of structural and biochemical modifications identified for the integument of B. alvarengai seems to conjugate aspects relevant to both, heat exchange and water balance, allowing for this species to explore basking as an efficient thermoregulatory strategy. J. Morphol. 276:1172-1182, 2015. © 2015 Wiley Periodicals, Inc.

The role of nicotine, cotinine and caffeine on the electrochemical behavior and bacterial colonization to cp-Ti

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)