The Rubiaceae family in the Carrancas Mountain Complex, state of Minas Gerais, southeastern Brazil

Rubiaceae is the fourth largest family of the angiosperms in terms of species diversity worldwide. It is present in all plant physiognomies and occupies various vegetation strata, being one of the most important components of tropical vegetation. It is easily recognized by the opposite leaves, interpetiolar stipules, gamopetalous corolla, and inferior ovary. The main objective of this study was to investigate the diversity of the Rubiaceae in the Carrancas Mountain Complex, Minas Gerais, Brazil. This region encompasses approximately 17,609 km2, extending from the southern border of the state of Minas Gerais, approaching the Itatiaia Plateau, to the Sao Joao del-Rei and Barbacena region, where the Sao Francisco River basin begins. It includes the municipalities of Lavras, Itumirim, Ingaí, Itutinga, Carrancas, and Minduri. Situated in an ecotone between the Atlantic Forest and Cerrado domains, it presents a surface covered by various vegetation types, such as campo rupestre, savannas, open fields, scrublands, seasonal semideciduous forests, riparian or gallery forests, and cloud forests at the higher elevations. A total of 681 herbarium specimens were analysed, most of them deposited at the ESAL herbarium, which holds most of the collections made in the region. In this study, 26 genera and 51 species were recorded. These represent noteworthy 37.7% of the genera and 13.5% of the species of Rubiaceae recorded in Minas Gerais, including 14 endemic species to Brazil. Borreria and Palicourea were the most diverse genera (five species each), followed by Cordiera, Galianthe, and Psychotria (four species each). Therefore, this work enriches the taxonomic knowledge of the Rubiaceae family in the state of Minas Gerais, particularly for the flora of the Carrancas Mountain Complex

Cs2NaAl1-xCrxF6: A family of compounds presenting magnetocaloric effect

In this paper we explore the magnetocaloric effect (MCE) of chromium-doped elpasolite Cs2NaAl1-x,CrxF6 (x = 0.01 and 0.62) single crystals. Magnetization and heat capacity data show the magnetocaloric potentials to be comparable to those of garnets, perovskites, and other fluorides, producing magnetic entropy changes of 0.5 J/kg K (x = 0.01) and 11 J/kg K (x = 0.62), and corresponding adiabatic temperature changes of 4 and 8 K, respectively. These values are for a magnetic field change of 50 kOe at a temperature around 3 K. A clear Schottky anomaly below 10 K, which becomes more apparent when an external magnetic field is applied, was observed and related to the splitting of the Cr3+ energy levels. These results hint at a new family of materials with potential wide use in cryorefrigeration

Karyotype characterization of two populations of Vernonia geminata (Asteraceae, Vernonieae) using banding and FISH techniques

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)In order to extend our knowledge concerning karyotypes of the genus Vernonia, we applied various techniques of chromosome banding, including AgNOR and triple staining with the fluorochromes CMA/DA/DAPI (CDD), and of fluorescent in situ hybridization (FISH) for the 45S rDNA probe to specimens of two populations of Vernonia geminata collected from an open-pasture area, in southern Brazil. B chromosomes were observed in one of the populations. Both populations of V. geminata presented a pair of CMA(3)(+) terminal bands and one pair of chromosomes with terminal AgNOR banding. The FISH evidenced, in one population, two pairs of small sites of 45S rDNA; these being two small terminal sites and two centromeric sites. In the other population, there was only one pair of small terminal sites and two sites in two B chromosomes, one in each chromosome. There was coincidence of localization between CMA(+) and NOR bands with one of the small terminal sites of 45S rDNA of one chromosome of the normal complement, but not in B chromosomes.11442044212Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

On the thermal characterization of solids by photoacoustic calorimetry: thermal diffusivity and linear thermal expansion coefficient

CNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOIn this paper, we resume a straightforwardly methodology that can be employed for accurate thermal diffusivity measurement by photoacoustics. The proposed methodology involves measurements in the thermally thick sample regime with normalization using a thermally thin reference sample, as well as consideration of the sample's thermoelastic bending in both the thermally thin and thick regime. The usefulness of the method has been demonstrated with measurements in test samples of different materials. The possibilities of the method to account for linear thermal expansion coefficient have been discussed too. It has been demonstrated that for the determination of this parameter the sample must be in the ideal thermally thick regime, i.e. the range of modulation frequencies used must lie well above the cut-off frequency between the thermally thin and thick regimes. In other words, this cut-off frequency must be very small. Although this condition is very difficult to be achieved in praxis, in order to account for it, a method is proposed here that involves measurements in samples with different thicknesses and uses an extrapolation procedure.In this paper, we resume a straightforwardly methodology that can be employed for accurate thermal diffusivity measurement by photoacoustics. The proposed methodology involves measurements in the thermally thick sample regime with normalization using a thermally thin reference sample, as well as consideration of the sample's thermoelastic bending in both the thermally thin and thick regime. The usefulness of the method has been demonstrated with measurements in test samples of different materials. The possibilities of the method to account for linear thermal expansion coefficient have been discussed too. It has been demonstrated that for the determination of this parameter the sample must be in the ideal thermally thick regime, i.e. the range of modulation frequencies used must lie well above the cut-off frequency between the thermally thin and thick regimes. In other words, this cut-off frequency must be very small. Although this condition is very difficult to be achieved in praxis, in order to account for it, a method is proposed here that involves measurements in samples with different thicknesses and uses an extrapolation procedure.6145258CNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOSem informaçãoAgências de fomento estrangeiras apoiaram essa pesquisa, mais informações acesse artig

In vitro determination of the sun protection factor of sunscreens through photoacoustic spectroscopy: A new approach

The investigation of the sun protection factor (SPF) and the efficacy of ultraviolet absorber ingredients are extremely important items for the cosmetic industry. The development of new efficient in vitro methodologies for these investigations is an essential condition for the evolution of sunscreens. The most accepted test for assessing the efficacy of sunscreens is the in vivo (in humans) SPF determination, following validated and worldwide adopted methodologies like those regulated by FDA (USA), COLIPA (Europe) and JCIA (Japan). However, due to the high costs and time consumption of in vivo SPF determination, the constant development of in vitro methods able to predict the in vivo SPF is very important. The present study evaluates different experimental methods for in vitro SPF determination – photoacoustic spectroscopy (PAS) and transmission spectroscopy (TS), employing different substrates (PMMA and VitroSkin®) and concentrations (0.8 mg/cm2 and 2 mg/cm2). Results are compared to the labeled SPF. The high correlation between the labeled SPF and the SPF determined by PAS expands the application of this technique in the photobiology field

High sensitivity thermal lens microscopy: Cr-VI trace detection in water

CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPIn this work, a low detection limit for hexavalent chromium in water of parts per trillions (21 ng/L) was achieved using a micro -spatial thermal lens spectroscopy setup with coaxial counter -propagating pump and probe laser beams and an integrated passive optical Fabry-Perot resonator, aided with a well -established diphenyl carbazide colorimetric method. Cr-VI concentrations in the range of mu g/L, i.e. well -below the toxicity thresholds in humans and animals (26 and 190 mg/L respectively) and below those delimited by international regulations for drink water (similar to 0.05-0.5 mg/L), have been obtained by measurements in bottled and tap water samples. The developed thermal lens microscope is also capable to detect Cr-VI directly in potassium dichromate solutions using pump beam wavelengths within the very low optical absorption region in the visible part of the spectrum, i.e., without the use of any calorimetric method.170260265CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPCONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPSem informaçãoSem informaçãoThis work was supported by Research Grants SIP-IPN 2014006, 20150390, 20160144 and CONACyT 2015-02-1042 and 264093. H. Cabrera gratefully acknowledges ICTP TRIL as well as the Associateship Programs. A. M. M. acknowledges the support of the Brazilian Agencies CNPq and FAPESP. The support of COFAA-IPN by the SIBE and BEIFI programs is also acknowledged

Photosynthesis in eucalyptus studied by the open photoacoustic technique: Effects of irradiance and temperature

This work demonstrates the usefulness of the Open Photoacoustic Cell Technique to study the effects of irradiance and temperature on photosynthesis. bl vivo and ill situ photosynthetic induction measurements were performed in three different species of eucalyptus plants (E. grandis, E. urophylla, and E, urograndis) previously dark-adapted at different temperatures. Photosynthetic activity curves were built as a function of light intensity, indicating the occurrence of photosynthesis saturation. E. urograndis presented higher photosynthetic activity than the other species, especially at low temperature, indicating its tolerance to stress conditions. The incidence of background saturation light of various intensities allowed the irt situ study of photoinhibition in eucalyptus plants through open photoacoustics. (C) 2001 MAIK Nauka/Interperiodica

Application of thermal lens microscopy (TLM) for measurement of Cr(VI) traces in wastewater

Sem informaçãoIn this work, we demonstrate for the first time that Thermal Lens Microscopy technique (TLM) can be applied to monitor the dynamics of a photocatalytic process in-sins. The photocatalytic reduction of hexavalent chromium -Cr(VI)- in aqueous solution using CdS and irradiated with visible light is monitored by TLM. Since the values of Cr(VI) concentration obtained after the photocatalytic process were close to those imposed by the international regulations for drinking water, the use of TLM allowed its measurement with a better reliability than with UV spectroscopy, usually used in this kind of analysis.232305309Sem informaçãoSem informaçãoSem informaçãoThis work was supported by SIP, IPN (Research Grants SIP: 20170545, 20170802, 20181764, and 20180305) and CONACYT (FC2015-02-1042, 264093, PN2016-012482, CB2016-285711) projects. COFAA-IPN by the SIBE and BEIFI programs is also acknowledged. L. A. Hernández-Carabalí thanks CONACyT and BEIFI for scholarships support. E. Cedeño gratefully acknowledges the support of the SECITI for granting a postdoctoral fellowship under the agrément SECITI/077/2017. HC would like to express gratitude to ICTP for support of this work through the Research Associateship and TRIL Programs

Photosynthetic induction in Eucalyptus urograndis seedlings and cuttings measured by an open photoacoustic cell

Photosynthetic induction in leaves of four-month-old Eucalyptus urograndis seedlings and of cuttings obtained from adult trees that were previously dark-adapted was studied by the in vivo and in situ Open Photoacoustic Cell Technique, Results for the gas exchange component of the photoacoustic (PA) signal were interpreted considering that the gas uptake component would have a phase angle nearly opposite to that of the oxygen evolution component. By subtracting the thermal component from the total PA signal, we studied the competition between gas uptake and oxygen evolution during the photosynthetic induction. Seedlings presented a net oxygen evolution prior to cuttings, but cuttings reached a higher steady-state photosynthetic activity. The chlorophyll (Chl) a/b ratio and the Chl fluorescence induction characteristic F-v/F-m were significantly higher for cuttings, while there was no difference between samples in stomata density and leaf thickness. Thus the differences in PA signals of seedlings and cuttings are associated to differences between the photosystem 2 antenna systems of these samples