Automatic stress exaggeration by prosody modification to assist language learners perceive sentence stress

In this paper, we propose a set of automatic stress exaggeration methods that can enlarge the differences between stressed and unstressed syllables. Our stress exaggeration methods can be used in computer-aided language learning systems to assist second language learners perceive stress patterns. The intention of our automatic stress exaggeration methods is to support hyper-pronunciation training which is commonly used in classrooms by teachers. In hyper-pronunciation training, exaggeration is used to help learners increase their awareness of acoustic features and effectively apply these features into their pronunciation. Duration, pitch and intensity have been claimed to be the main acoustic features that are closely related to stress in English language. Thus, four stress exaggeration methods are proposed in this paper: (i) duration-based stress exaggeration, (ii) pitch-based stress exaggeration, (iii) intensity-based stress exaggeration, and (iv) a combined stress exaggeration method that integrates the duration-based, pitch-based and intensity-based exaggeration methods. Our perceptual experimental results show that resynthesised stimuli by our proposed stress exaggerated methods can help learners of English as a Second Language (ESL) better perceive English stress patterns significantly.     

Nitrogen fixation of and N transfer from cowpea, mungbean and groundnut when intercropped with maize

Grain legumes are used widely in intercropping systems. However, quantitative and comparative data available as to their N₂ fixation and N beneficial effect on the companion crop in intercropping systems are scarce. Hence, studies were conducted to ascertain the above when cowpea (Vigna unguiculata L.), mungbean (Vigna radiata L.) and groundnut (Arachis hypogaea L.) were intercropped with maize. The study was¹⁵N-aided and made outdoors in basins (30 L) filled with 38 kg of soil.¹⁵N labelling was effected by incorporating¹⁵N-tagged plant material or applying¹⁵N-labelled fertilizer along with sucrose to stabilize¹⁵N enrichment in the soil during the experimental period. Intercropped groundnut fixed the highest amount of nitrogen from the atmosphere (i.e. 552 mg plant^–1), deriving 85% of its N from the atmosphere. Intercropped cowpea and mungbean fixed 161 and 197 mg N plant^–1, obtaining 81% and 78% of their N content from the atmosphere, respectively. The proportion of N derived by maize from the associated legume varied from 7-11% for mungbean, 11–20% for cowpea and 12–26% for groundnut which amounted to about 19–22, 29–45 and 33–60 mg N maize plant^–1, respectively. The high nitrogen fixation potential of groundnut in dual stands and its relatively low harvest index for N have apparently contributed to greater N-benefical effect on the associated crop.     

Mechanism of Action of AminoCBIs: Highly Reactive but Highly Cytotoxic Analogues of the Duocarmycins

Duocarmycins are highly cytotoxic natural products that have potential for development into anticancer agents. Herein we describe proposed but previously unidentified NH analogues of the DNA‐alkylating subunit and characterise these by solvolysis studies, NMR and computational modelling. These compounds are shown to be the exclusive intermediates in the solvolysis of their seco precursors and to possess very similar structural features to the widely studied O‐based analogues, apart from an unusually high basicity. The measured pK_a of 10.5 implies that the NH compounds are fully protonated under physiological conditions. Remarkably, their extremely high reactivity (calculated hydrolysis rate 10⁸ times higher for protonated NH compared to the neutral O analogue) is still compatible with potent cytotoxicity, provided the active species is formed in the presence of cells. These surprising findings are of relevance to the design of duocarmycin‐based tumour‐selective therapies.     

Amplification of Ki-ras and elevation of MAP kinase activity during mammary tumor progression in C3(1)/SV40 Tag transgenic mice

We have previously documented that transgenic mice expressing SV40 Tag regulated by the rat prostatic steroid-binding protein C3(1) 5'-flanking region display multistage mammary tumorigenesis. To delineate genetic changes associated with mammary tumor progression, comparative genomic hybridization (CGH) was performed. CGH revealed a consistent gain of the telomeric region of chromosome 6. This region contains the Ki-ras proto-oncogene. Analyses of genomic DNA by Southern blot demonstrated up to 40-fold amplification of the Ki-ras gene. Ki-ras amplification was detected in 12, 46 and 68% of tumors from 4, 5 and 6 month old mice, respectively, whereas no amplifications were found in any preneoplastic mammary tissues. Tumors bearing Ki-ras gene amplification exhibited high levels of Ki-ras RNA and protein. The over-expressed Ki-Ras protein in these tumors appeared functionally active as indicated by the elevated MAP kinase activity. These data demonstrate that while Ki-ras amplification might not be an early event, there is a strong association between Ki-ras amplification and over-expression and mammary tumor progression in this model. This study also shows that CGH is a powerful and useful technique for identifying chromosomal copy number changes during tumor progression, and that this model may provide a predictable in vivo system for studying gene amplification.     

Potato and soy peptides alter caecal fermentation and reduce serum non‐HDL cholesterol in rats fed cholesterol

We examined the effect of potato peptides (PPC) in rats fed a cholesterol‐enriched diet, in comparison with two cholesterol‐enriched diets containing soy peptides (SPC) or casein (CNC), and a cholesterol‐free diet containing casein (CN) for 4 weeks. The serum non‐high‐density lipoprotein (HDL) cholesterol level was lower in the PPC‐ (–18.39%) and SPC‐fed (–32.76%) groups (p <0.05) than in the CNC‐fed group at the end of the feeding period. The low‐density lipoprotein receptor mRNA level in the PPC‐fed group, and cholesterol 7α‐hydroxylase and scavenger receptor class B type 1 mRNA levels in the SPC‐fed group, were higher (p <0.05) than in the CN‐ and CNC‐fed groups. Faecal neutral sterol and caecal short‐chain fatty acid concentrations in the PPC‐ and SPC‐fed groups were higher (p <0.05) than in the CN‐ and CNC‐fed groups. The faecal total acidic sterol concentration was higher in the SPC‐fed group than in the CN‐ and PPC‐fed groups. Caecal anaerobe and Bifidobacterium populations were higher (p <0.05) in the PPC‐ and SPC‐fed groups than in the CN‐fed group. This study suggests that potato peptides, as soy peptides, alter caecal fermentation and steroid absorption and reduce the serum non‐HDL cholesterol level in rats fed cholesterol.     

An efficient anonymous authentication protocol in multiple server communication networks (EAAM)

In a multi-server authentication environment, a user only needs to register once at a central registration place before accessing the different services on the different registered servers. Both, from a user point of view as for the management and maintenance of the infrastructure, these types of environments become more and more popular. Smartcard- or smartphone-based approaches lead to more secure systems because they offer two- or three-factor authentication, based on the strict combination of the user’s password, the user’s biometrics and the possession of the device. In this paper, we propose an efficient anonymous authentication protocol in multiple server communication networks, called the EAAM protocol, which is able to establish user anonymity, mutual authentication, and resistance against known security attacks. The novelty of the proposed scheme is that it does not require a secure channel during the registration between the user and the registration center and is resistant to a curious but honest registration system. These features are established in a highly efficient way with the minimum amount of communication flows between user and server during the establishment of the secret shared key and by using light-weight cryptographic techniques such as Chebyshev chaotic map techniques and symmetric key cryptography. The performance and security of the protocol are analyzed and compared with the latest new proposals in this field.     

Cowpea: an overview on its nutritional facts and health benefits

Cowpea (Vigna unguiculata) is a legume consumed as a high‐quality plant protein source in many parts of the world. High protein and carbohydrate contents with a relatively low fat content and a complementary amino acid pattern to that of cereal grains make cowpea an important nutritional food in the human diet. Cowpea has gained more attention recently from consumers and researchers worldwide as a result of its exerted health beneficial properties, including anti‐diabetic, anti‐cancer, anti‐hyperlipidemic, anti‐inflammatory and anti‐hypertensive properties. Among the mechanisms that have been proposed in the prevention of chronic diseases, the most proven are attributed to the presence of compounds such as soluble and insoluble dietary fiber, phytochemicals, and proteins and peptides in cowpea. However, studies on the anti‐cancer and anti‐inflammatory properties of cowpea have produced conflicting results. Some studies support a protective effect of cowpea on the progression of cancer and inflammation, whereas others did not reveal any. Because there are only a few studies addressing health‐related effects of cowpea consumption, further studies in this area are suggested. In addition, despite the reported favorable effects of cowpea on diabetes, hyperlipidemia and hypertension, a long‐term epidemiological study investigating the association between cowpea consumption and diabetes, cardiovascular disease and cancer is also recommended. © 2018 Society of Chemical Industry     

Health‐beneficial properties of potato and compounds of interest

Potatoes have shown promising health‐promoting properties in human cell culture, experimental animal and human clinical studies, including antioxidant, hypocholesterolemic, anti‐inflammatory, antiobesity, anticancer and antidiabetic effects. Compounds present such as phenolics, fiber, starch and proteins as well as compounds considered antinutritional such as glycoalkaloids, lectins and proteinase inhibitors are believed to contribute to the health benefits of potatoes. However, epidemiological studies exploring the role of potatoes in human health have been inconclusive. Some studies support a protective effect of potato consumption in weight management and diabetes, while other studies demonstrate no effect and a few suggest a negative effect. As there are many biological activities attributed to the compounds present in potato, some of which could be beneficial or detrimental depending on specific circumstances, a long‐term study investigating the association between potato consumption and diabetes, obesity, cardiovascular disease and cancer while controlling for fat intake is needed. © 2016 Society of Chemical Industry     

Piecewise Maximal Similarity for Ad-hoc Social Networks

Computing Profile Similarity is a fundamental requirement in the area of Social Networks to suggest similar social connections that have high chance of being accepted as actual connection. Representing and measuring similarity appropriately is a pursuit of many researchers. Cosine similarity is a widely used metric that is simple and effective. This paper provides analysis of cosine similarity for social profiles and proposes a novel method to compute Piecewise Maximal Similarity between profiles. The proposed metric is 6% more effective to measure similarity than cosine similarity based on computations on real data.     

Effect of K on nitrogen fixation of intercrop groundnut and the competition between intercrop groundnut and maize

Application of adequate level of K has shown to improve the competitive ability of the legume in legume/grass mixtures. However, the effect of K on the competitive ability of grain legumes in legume/cereal intercropping systems has not been adequately studied. Hence, studies were made to ascertain if the effects of K could be exploited in improving the performance of groundnut (Arachis hypogaea L.) cv. No. 45 when intercropped with maize (Zea mays L.) cv. Badra. The study was conducted at the Faculty of Agriculture, University of Ruhuna, Kamburupitiya, Sri Lanka in 1988 in basins filled with 36 kg of soil. It involved establishing maize and groundnut as monocrops and as intercrops at three K levels viz. 0, 20 and 40 mg of K kg^–1 of soil. Monocrop maize and groundnut had 2 and 5 plants/basin, respectively while the intercrop had 1 maize plant and 3 groundnut plants/basin. The soil used was Red Yellow Podzolic which was tagged by incorporating¹⁵N-labelled plant material. When grown as a monocrop, K had no effect on the percent N derived from atmosphere, amount of N₂ fixed, dry matter production, pod yield and total N content of groundnut. However, when intercropped with maize lack of K application affected the above parameters significantly which was overcome by improving K level. Thus, the optimum level of K for groundnut was greater when intercropped than monocropped. A significant interaction between K level and cropping system was evident with regard to N₂ fixation, pod yield and total dry matter production of groundnut. Intercrop maize derived 30–35% of its N content from the associated groundnut plants which amounted to 13–22 mg N/plant. The amount of N supplied by groundnut to associated maize plant was not affected by K level. It appears that there is scope for alleviating growth depression of the legume component in legume/cereal intercropping systems by developing appropriate K fertilizer practices.