Physicochemical,thermal, and pasting properties of flours and starches of eight Brazilian maize landraces (Zea mays L.)

Both genetic and environmental factors create significant variation in the amount and quality of maize landrace constituents. Details on the flours and starch characteristics have not been fully investigated. The physicochemical, pasting and thermal properties of 8 promising cultivars were assessed in this study and those properties were correlated. Higher values of swelling and solubility (RJ – 13.14%; 14.39%), lipid content (MG – 5.53%), WBC (PR – 18.89%), and amylose content (PR – 27.43%) were found for those genotypes. Lower onset temperatures of gelatinization (To) were observed for RX-F1 (66.1 °C) as RX-F1 (68.7 °C) genotype showed the lower pasting temperatures. A wide range of viscosity values was found among the maize landraces (MG-F0, 343 mPa s and RJ-F1, 175 mPa s) as well as for the retrogradation (R8C-F1, 796 mPa s and RX-F1, 22 mPa s). ATR-FTIR spectroscopy revealed amylose, amylopectin, lipids, and proteins as major flours constituents and their differences were discriminated by PCA analysis.     

PTR-ToF-MS, A Novel, Rapid, High Sensitivity and Non-Invasive Tool to Monitor Volatile Compound Release During Fruit Post-Harvest Storage: The Case Study of Apple Ripening

In the present study, the potential of PTR-ToF-MS for addressing fundamental and technical post-harvest issues was tested on the non-destructive and rapid monitoring of volatile compound evolution in three apple cultivars (‘Golden Delicious’, ‘Braeburn’ and ‘Gold Rush’) during 25 days of post-harvest shelf life ripening. There were more than 800 peaks in the PTR-ToF-MS spectra of apple headspace and many of them were associated with relevant compounds. Besides the ion produced upon proton transfer, we used the ion at mass 28.031 (C₂H ₄ ⁺ ) produced by charge transfer from residual O ₂ ⁺ as a monitor for ethylene concentration. ‘Golden Delicious’ apples were characterised by higher ethylene emission rates than ‘Gold Rush’ and ‘Braeburn’, and quantitative comparison has been supported by two segment piecewise linear model fitting. Ester evolution during post-harvest ripening is strongly dependent on endogenous ethylene concentration levels. For ‘Golden Delicious’ and ‘Braeburn’, sesquiterpenes (alpha-farnesene) exhibited a fast response to ethylene emission followed by a rapid decline after the endogenous ethylene maximum peak. Carbonyl compounds displayed a different time evolution as compared to esters and terpenes and did not show any evident relationship with ethylene. Methanol and ethanol concentrations during the entire storage period did not change significantly. We show how multivariate analysis can efficiently handle the large datasets produced by PTR-ToF-MS and that the outcomes obtained are in agreement with the literature. The different volatile compounds could be simultaneously monitored with high time resolution, providing advantages over the more established techniques for the investigation of VOC dynamics in fruit post-harvest storage trials.     

Measuring the effects of European Regional Policy on economic growth: A regression discontinuity approach

Given the increasing share of the EU budget devoted to Regional Policy, several studies have tried to identify the impact of structural funds on economic growth. However, so far no consensus has been reached. We assess Regional Policy effects through a non‐experimental comparison group method, the regression discontinuity design, and a novel regional dataset for the 1994–2006 period. We exploit the allocation rule of EU transfers by comparing regions with a per capita GDP level just below the eligibility threshold (75% of EU average) with those just above. Our findings show a positive impact of EU Regional Policy on economic growth.     

How miRNAs Regulate Schwann Cells during Peripheral Nerve Regeneration—A Systemic Review

A growing body of studies indicate that small noncoding RNAs, especially microRNAs (miRNA), play a crucial role in response to peripheral nerve injuries. During Wallerian degeneration and regeneration processes, they orchestrate several pathways, in particular the MAPK, AKT, and EGR2 (KROX20) pathways. Certain miRNAs show specific expression profiles upon a nerve lesion correlating with the subsequent nerve regeneration stages such as dedifferentiation and with migration of Schwann cells, uptake of debris, neurite outgrowth and finally remyelination of regenerated axons. This review highlights (a) the specific expression profiles of miRNAs upon a nerve lesion and (b) how miRNAs regulate nerve regeneration by acting on distinct pathways and linked proteins. Shedding light on the role of miRNAs associated with peripheral nerve regeneration will help researchers to better understand the molecular mechanisms and deliver targets for precision medicine.     

Generalized Discrete Radon Transforms and Their Use in the Ridgelet Transform

We introduce and study a new class of Radon transforms in a discrete setting for the purpose of applying them to the ridgelet and curvelet transforms. We give a detailed analysis of the p-adic case and provide a closed-form formula for an inverse of the p-adic Radon transform. We give conditions for a scaled version of the generalized discrete Radon transform to yield a tight frame, and discuss a direct Radon matrix method for the implementation of a local ridgelet transform. We then study the effectiveness of some types of the generalized Radon transforms in reducing a type of noise known as speckle that is present in synthetic aperture radar (SAR) imagery. Flavia Colonna received the M.A. degree and the Ph.D degree in mathematics from the University of Maryland (College Park) in 1980 and 1985, respectively. She was an assistant professor at the University of Bari (Italy) until she joined the faculty of George Mason University in 1986, where she is currently professor of mathematics. Her research interests include discrete harmonic analysis, integral geometry, potential theory, and classical complex function theory. Glenn R. Easley received the B.S. degree (with honors) and the M.A. degree in mathematics from the University of Maryland, College Park, in 1993 and 1996, respectively, and the Ph.D. degree in computational science and informatics from George Mason University in 2000. Since 2000, he has been working for System Planning Corporation in signal and image processing. His research interests include computational harmonic analysis, wavelet analysis, synthetic aperture radar, deconvolution and computer vision.This revised version was published online in June 2005 with correction to CoverDate     

Embryonic diapause and its regulation

Embryonic diapause, a condition of temporary suspension of development of the mammalian embryo, occurs due to suppression of cell proliferation at the blastocyst stage. It is an evolutionary strategy to ensure the survival of neonates. Obligate diapause occurs in every gestation of some species, while facultative diapause ensues in others, associated with metabolic stress, usually lactation. The onset, maintenance and escape from diapause are regulated by cascades of environmental, hypophyseal, ovarian and uterine mechanisms that vary among species and between the obligate and facultative condition. In the best-known models, the rodents, the uterine environment maintains the embryo in diapause, while estrogens, in combination with growth factors, reinitiate development. Mitotic arrest in the mammalian embryo occurs at the G0 or G1 phase of the cell cycle, and may be due to expression of a specific cell cycle inhibitor. Regulation of proliferation in non- mammalian models of diapause provide clues to orthologous genes whose expression may regulate the reprise of proliferation in the mammalian context.     

Study on bisphenol-A polycarbonates samples crystallized by acetone vapor induction

Bisphenol-A polycarbonate (PC) is an important amorphous engineering polymer, which can have its crystallinity induced by special environmental conditions. Such crystallization can alter PC properties leading to flaws during its use or to new applications. Cast film samples of PC, prepared from chloroform solutions, were submitted to acetone vapor and characterized by polarized light microscopy (PLM), differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FTIR). PLM showed that the PC crystalline structure was presented as spherulites of different sizes. DSC analysis exhibited a multiple melting behavior for the crystalline structure. FTIR has presented bands shifting and intensity decrease, compared to the samples before treatment. Compression molded samples were characterized by scanning electron microscopy (SEM), DSC and mechanical properties tests. For those samples, DSC also showed the presence of a crystalline phase, with a little increase on surface rugosity observed through SEM. Stress–strain tests presented a decrease on samples performance after acetone exposure.     

Preparation of MnO<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript>/AISI 304 Austenitic Stainless Steel Monoliths for Catalytic Combustion of Ethyl Acetate

Abstract  

The objective of this study is to explore the treatment conditions of austenitic stainless steel, AISI 304, for catalytic devices used in volatile organic compounds (VOCs) combustion. The variables studied were treatment exposure time, temperature and atmosphere. AISI 304 steel surface resulted in different morphologies depending on temperature and atmosphere. The oxide layer was composed of mixed oxides of Cr–Fe and Cr–Mn–Fe, forming octahedral and hexagonal crystals. The addition of manganese with the objective of reaching the ideal Mn/Fe ratio improved notably the catalytic performance.