Essential Oil of Betula pendula Roth. Buds

The essential oil of Betula pendula Roth. buds was obtained using both hydrodistillation and microdistillation techniques and their chemical compositions were analyzed using both gas chromatography (GC) and gas chromatography–mass spectrometry (GC-MS). Overall, more than 50 compounds were identified representing 80% and 92% for hydrodistillation and microdistillation, respectively. The main components (by hydrodistillation and microdistillation, respectively) found were α-copaene (12% and 10%), germacrene D (11% and 18%) and δ-cadinene (11% and 15%) in the analyzed essential oils. The microdistillation technique proved to be a useful tool and compliant alternative when compared to hydrodistillation

Extensive Reading in the English as a Second Language Classroom – Motivating and Engaging Male Emirati Students in a Higher Education Context

The purpose of this phenomenological study is to discover factors that motivate male Emirati ESL students studying in a higher education Foundation program to read extensively in English. Research questions seek to discern motivational factors, underlying motivational constructs, practical strategies used to motivate the male students to read and how these approaches could be utilized in a wider context in the future. The study is novel due to lack of qualitative research from the perspective of students and teachers in the field of extensive reading in differing contexts. The research will also serve to fill the gaps in the area of L2 reading motivation. The data was gathered using semi-structured interviews with male students and focus group with teachers involved in an extensive reading program (ERP) in an attempt to draw on the lived experiences of the participants. The need for the study was apparent due to the perceived lack of reading in English when the male students enter higher education with the aim to study English affording access to undergraduate studies in higher education. The development of reading fluency is considered a requirement for language learning and enhancement of cognition for self- development purposes so that individuals can flourish in higher education. An interpretive phenomenological analysis was adopted using bracketing and reduction of the transcribed interviews and focus groups to develop a table of master themes to explain the phenomenon of reading motivation among male Emirati ESL students. The findings suggest the teacher’s role is that of a ‘coach’, a role much more influential than was once thought. Extrinsic motivation is an essential component of the process of change and once situational interest and stimulating tasks shrouded in positivity are used the transformation of extrinsic motivation to intrinsic motivation becomes apparent. A range of recommendations were made including the implementation of the extensive reading program throughout the whole institution and applying the same methodology in the Arabic language programs. At the same time the intricacies of motivating students in an unfamiliar context needs to be considered. The study concludes by suggesting the issues raised be addressed by institutional administrators so that extensive reading programs in English become an integral part of the reading curriculum in ESL programs throughout the UAE and the wider Arab worl

A new meet-in-the-middle attack on the IDEA block cipher

In this paper we introduce a novel meet-in-the-middle attack on the IDEA block cipher. The attack consists of a precomputation and an elimination phase. The attack reduces the number of required plaintexts significantly for 4 and 4.5 rounds, and, to the best of our knowledge, it is the first attack on the 5-round IDEA. © Springer-Verlag Berlin Heidelberg 2004

Forecasting of Suspended Sediment in Rivers Using Artificial Neural Networks Approach

Suspended sediment estimation is important to the water resources management and water quality problem. In this article, artificial neural networks (ANN), M5tree (M5T) approaches and statistical approaches such as Multiple Linear Regression (MLR), Sediment Rating Curves (SRC) are used for estimation daily suspended sediment concentration from daily temperature of water and streamflow in river. These daily datas were measured at Iowa station in US. These prediction aproaches are compared to each other according to three statistical criteria, namely, mean square errors (MSE), mean absolute relative error (MAE) and correlation coefficient (R). When the results are compared ANN approach have better forecasts suspended sediment than the other estimation methods

Enhancing acetic acid and 5-hydroxymethyl furfural tolerance of C. saccharoperbutylacetonicum through adaptive laboratory evolution

Supplementary material related to this article can be found, in the online version, at doi:https://doi.org/10.1016/j.procbio.2020.11.013.In this study, adaptive laboratory evolution (ALE) was applied to isolate four strains of Clostridium saccharoperbutylacetonicum able to grow in the presence of hemicellulosic hydrolysate inhibitors unsupported by the parental strain. Among them, isolate RAC-25 presented the best fermentative performance, producing 22.1g/L of ABE and 16.7g/L of butanol. Genome sequencing revealed a deletion in the arabinose transcriptional repressor gene (araR) and a mutation in the anti-sigma factor I that promoted a downregulation of sigI. Gene expression analysis indicated high expression of genes related to H+-pumps (ATP synthases), proline biosynthesis (gamma phosphate reductase) and chaperonins (Grol), suggesting an integrated mechanism that is probably coordinated by the repression of sigI. Therefore, in addition to highlighting the power of ALE for selecting robust strains, our results suggest that sigI and araR may be interesting gene targets for increased tolerance toward inhibitor compounds relevant for lignocellulosic biofuels production.The authors would like to thank the Brazilian Center for Research in Energy and Materials (CNPEM) for providing access to the bioprocess facility of the Brazilian Biorenewables National Laboratory, and CNPq (400803/2013-5), FCT (UID/BIO/04469), BioTecNorte Operation (NORTE-01-0145-FEDER-000004) and Portuguese Biological Data Network” (ref. LISBOA-01-0145-FEDER-022231) for financial support.info:eu-repo/semantics/publishedVersio

Rapid chemical analysis and antiprotozoal effect of the solvent extracts and the essential oil of Artemisia indica

Artemisia indica is used as antipyretic in malarial fevers during malaria outbreaks in India [1]. We selected this plant because reports concerning the presence of artemisinin is contradictory, the content of methoxyflavonoids that potentiate the antimalarial efficacy of artemisinin has remained unstudied and the essential oil of the plant from different regions shows great chemical variations. Solvent extracts [petroleum ether, n-hexane, dichloromethane, acetone, MeOH or EtOH (96, 80 or 60% v/v), and hot water] of A. indica leaves originated from the West Bengal region (India) were assessed by HPLC-DAD and HPLC-MS for the content of artemisinin and the characteristic Artemisia methoxyflavonoids, eupatin, casticin, chrysoplenetin, cirsilineol, chrysosphenol-D and artemetin. None of the extracts contained artemisinin or the methoxyflavonoids chrysosphenol-D and artemetin, while all extracts contained chrysoplenetin. Eupatin, casticin and cirsilineol were found in all extracts except for the p. ether, n-hexane and hot water infusion. The acetone and EtOH extracts contained the highest levels of polymethoxyflavonoids (1.15 – 1.17%), whereas the infusion was devoid of them. The essential oil of the plant was obtained by hydrodistillation and analyzed by GC and GC-MS simultaneously. Of the 92 compounds detected in the oil, camphor (13.0%) and caryophyllene oxide (10.87%) were the major components. All solvent extracts and the volatile oil showed in vitro antimalarial activity (1.8 – 20 µg/mL). Except for the infusion, all extracts were also active against other parasitic protozoa (Trypanosoma b. rhodesiense, T. cruzi, Leishmania donovani). This is the first study investigating both artemisinin and polymethoxyflavonoid content and detailed in vitro antiprotozoal potential of A. indica extracts and the essential oil