Subsidized food consumption systems in low income countries : the Pakistan experience

"#2063"--handwritten on coverIncludes bibliographical reference

Contribution to the study of semiochemical slow release formulations. Development of flash chromatographic methods

Peer reviewe

Universality in movie rating distributions

In this paper histograms of user ratings for movies (1,...,10) are analysed. The evolving stabilised shapes of histograms follow the rule that all are either double- or triple-peaked. Moreover, at most one peak can be on the central bins 2,...,9 and the distribution in these bins looks smooth `Gaussian-like' while changes at the extremes (1 and 10) often look abrupt. It is shown that this is well approximated under the assumption that histograms are confined and discretised probability density functions of L\'evy skew alpha-stable distributions. These distributions are the only stable distributions which could emerge due to a generalized central limit theorem from averaging of various independent random avriables as which one can see the initial opinions of users. Averaging is also an appropriate assumption about the social process which underlies the process of continuous opinion formation. Surprisingly, not the normal distribution achieves the best fit over histograms obseved on the web, but distributions with fat tails which decay as power-laws with exponent -(1+alpha) (alpha=4/3). The scale and skewness parameters of the Levy skew alpha-stable distributions seem to depend on the deviation from an average movie (with mean about 7.6). The histogram of such an average movie has no skewness and is the most narrow one. If a movie deviates from average the distribution gets broader and skew. The skewness pronounces the deviation. This is used to construct a one parameter fit which gives some evidence of universality in processes of continuous opinion dynamics about taste.Comment: 8 pages, 5 figures, accepted for publicatio

Seven benzimidazole pesticides combined at sub-threshold levels induce micronuclei in vitro

This article is made available through the Brunel Open Access Publishing Fund. This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http:// creativecommons.org/licenses/by-nc/3.0/), which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.Benzimidazoles act by disrupting microtubule polymerisation and are capable of inducing the formation of micronuclei. Considering the similarities in their mechanisms of action (inhibition of microtubule assembly by binding to the colchicine-binding site on tubulin monomers), combination effects according to the principles of concentration addition might occur. If so, it is to be expected that several benzimidazoles contribute to micronucleus formation even when each single one is present at or below threshold levels. This would have profound implications for risk assessment, but the idea has never been tested rigorously. To fill this gap, we analysed micronucleus frequencies for seven benzimidazoles, including the fungicide benomyl, its metabolite carbendazim, the anthelmintics albendazole, albendazole oxide, flubendazole, mebendazole and oxibendazole. Thiabendazole was also tested but was inactive. We used the cytochalasin-blocked micronucleus assay with CHO-K1 cells according to OECD guidelines, and employed an automated micronucleus scoring system based on image analysis to establish quantitative concentration–response relationships for the seven active benzimidazoles. Based on this information, we predicted additive combination effects for a mixture of the seven benzimidazoles by using the concepts of concentration addition and independent action. The observed effects of the mixture agreed very well with those predicted by concentration addition. Independent action underestimated the observed combined effects by a large margin. With a mixture that combined all benzimidazoles at their estimated threshold concentrations for micronucleus induction, micronucleus frequencies of ~15.5% were observed, correctly anticipated by concentration addition. On the basis of independent action, this mixture was expected to produce no effects. Our data provide convincing evidence that concentration addition is applicable to combinations of benzimidazoles that form micronuclei by disrupting microtubule polymerisation. They present a rationale for grouping these chemicals together for the purpose of cumulative risk assessment.United Kingdom Food Standards Agenc

Development of natural semiochemical slow-release formulations as biological control devices

peer reviewedSemiochemicals – informative molecules used in insect-insect or plant-insect interactions – have been widely considered within various integrated pest management (IPM) strategies. In the present work, two sesquiterpenoids, E-β-farnesene and E-β-caryophyllene, were formulated for their properties as aphid enemy attractants. E-β-farnesene, the alarm pheromone of many aphid species, was also identified as a kairomone by attracting aphid predators and parasitoids. E-β-caryophyllene was identified as a potential component of the aggregation pheromone of the Asian ladybird, Harmonia axyridis Pallas, another aphid predator. The two products were purified from essential oils of Matricaria chamomilla L. (Asteraceae) and Nepeta cataria L. (Lamiaceae), respectively. Natural and biodegradable formulations were then investigated in order to deliver these molecules on crop fields for a long period of time as biological control devices. Due to their sensitivity to oxidation, both sesquiterpenes needed to be protected from oxygen degradation. For this purpose, alginate – hydrophilic matrix with low oxygen permeability – was used as polymer for the formulations: the main objective was to deliver semiochemicals in the air in a controlled way. Consequently, a careful selection of alginates was realised. Formulated beads showed different structural and encapsulation properties depending on various formulation factors. Alginate formulations were characterised by texturometry and by confocal microscopy in order to observe the distribution of semiochemicals in alginate network. The last step of alginate bead characterisation consisted in studying release rate of semiochemicals in laboratory-controlled conditions by optimised volatile collection system and validated fast GC analytical procedures Finally, the efficiency of formulations as aphid predator (Syrphidae species) and parasitoid (Aphidius ervi) attractants was demonstrated by field trapping and olfactometry experiments.SOLAPHI

Changing Times: The Renaissance, Scientific Revolution, and Reformation [6th grade]

This unit looks at the impact that the Renaissance, Scientific Revolution, and Reformation had on the world. It traces important people and ideas, and highlights the impact that each of these time periods had on the immediate and future world. For the Performance Task, the students create a newspaper, called The Changing Times that requires them to analyze the impact that inventions and ideas from these time periods had on the world, as well as look at futuristic inventions (to our time) and the possible impact they will have on our world

Pragmatic word learning in monolingual and bilingually exposed children

Humans are highly adaptable to a variety of challenging situations, as shown for example by increased echolocation abilities in the visually impaired (Schenkman & Nilsson, 2010). Multilingual input and interactions arguably create a particularly demanding environment, with added complexity and variation in the linguistic signal, a higher risk of communication failures and an increased amount of word forms to acquire. Despite this, and a lesser ability to rely on mutual exclusivity, bilingual children are able to quickly acquire a similar, and often greater vocabulary than their monolingual peers (De Houwer, Bornstein, & Putnick, 2014; Umbel, Pearson, Fernández, & Oller, 1992). A range of studies investigating attention to socio-pragmatic speaker cues found increased reliance on speaker cues in bilinguals (Colunga, Brojde, & Ahmed, 2012; Yow & Markman, 2011a, 2015). However, since these studies involved ignoring another conflicting cue, the results could have been related to inhibitory skills or to better attention to speaker generally, rather than to pragmatic inference per se, which relies on reasoning about communicative intentions. In five separate studies, we investigated the ability of a first (n=270, range=4;1- 6;2, mean age=5;3) and second (n=120, range=4;0-5;11, mean age=5;5) sample of monolingual and bilingually exposed children to use pragmatic cues to learn the meaning of a novel word in five different tasks where success could not be achieved by ignoring a salient cue. The tasks were: contrastive inference with prosodic stress, inference based on relative frequency of a referent, ostensive teaching of a subordinate category, ostensive teaching of an action word, and use of emotional affect. We found several developmental effects, and bilinguals to be more adult-like and to significantly outperform monolinguals (compared to a baseline control condition) in all tasks which involved reasoning about communicative intentions (or why the cue was provided, i.e., the first four tasks) but not when word referent mapping could be achieved without pragmatic reasoning (directly mapping emotional valence to referent valence, i.e., fifth task). We conclude that this thesis provides evidence for differences in the processing of pragmatic cues by bilingual and monolingual children which are not due solely to better inhibitory skills or to a general sensitivity to social cues such as prosody, eye gaze and pointing, but to performing true pragmatic inference by reasoning about communicative intentions in the context of word learning. In addition, we believe a distinction needs to be made between using social cues and reasoning about intentions, which might help provide insights about separate developmental timelines for exerting different types of pragmatic competence, with early abilities demonstrated by the bilingually exposed, particularly in acquisition contexts

Border Disorder – Cultures in Conflict Throughout the World

This unit is designed to look at various cultures throughout the world and examine the reason for conflict in each of them. By looking at snapshots of information for various cultures and situations (e.g. Africa, Israel/Palestine, India/Pakistan, North/South Korea), students come to the understanding that conflict is due to many factors, but there is always a matter of different perspective for each situation. The students look at the history of each situation from a factual standpoint, but they also are stretched to investigate and explore the perspectives of each as well. The students’ performance task has them creating a news show that interviews representatives of each side of the conflict as well as a “scholar” on the situation who has developed a solution to bring peace to the area