A randomised, double-blind, placebo controlled cross-over study to determine the gastrointestinal effects of consumption of arabinoxylan-oligosaccharides enriched bread in healthy volunteers

ABSTRACT: BACKGROUND: Prebiotics are food ingredients, usually non-digestible oligosaccharides, that are selectively fermented by populations of beneficial gut bacteria. Endoxylanases, altering the naturally present cereal arabinoxylans, are commonly used in the bread industry to improve dough and bread characteristics. Recently, an in situ method has been developed to produce arabinoxylan-oligosaccharides (AXOS) at high levels in breads through the use of a thermophilic endoxylanase. AXOS have demonstrated potentially prebiotic properties in that they have been observed to lead to beneficial shifts in the microbiota in vitro and in murine, poultry and human studies. METHODS: A double-blind, placebo controlled human intervention study was undertaken with 40 healthy adult volunteers to assess the impact of consumption of breads with in situ produced AXOS (containing 2.2 g AXOS) compared to non-endoxylanase treated breads. Volatile fatty acid concentrations in faeces were assessed and fluorescence in situ hybridisation was used to assess changes in gut microbial groups. Secretory immunoglobulin A (sIgA) levels in saliva were also measured. RESULTS: Consumption of AXOS-enriched breads led to increased faecal butyrate and a trend for reduced iso-valerate and fatty acids associated with protein fermentation. Faecal levels of bifidobacteria increased following initial control breads and remained elevated throughout the study. Lactobacilli levels were elevated following both placebo and AXOS-breads. No changes in salivary secretory IgA levels were observed during the study. Furthermore, no adverse effects on gastrointestinal symptoms were reported during AXOS-bread intake. CONCLUSIONS: AXOS-breads led to a potentially beneficial shift in fermentation end products and are well tolerated.     

Synthesis of deuterated fatty acids to investigate the biosynthetic pathway of disparlure,the sex pheromone of the Gypsy Moth, <Emphasis Type="Italic">Lymantria dispar</Emphasis>

The preparation and characterization of a series of deuterium-labeled intermediates used in the study of the biosynthetic pathway for disparlure, the sex pheromone of Lymantria dispar, is reported. The synthetic route starts with propargyl alcohol, and the deuterium atoms are introduced by deuteration of an alkyne precursor in the presence of Wilkinson's catalyst. The olefinic bond was created by the Wittig reaction of a suitable aldehyde with a common tetradeuterated phosphonium ylide intermediate. The presence of the expected label and its correct location were confirmed by both MS and ¹³C NMR. These compounds were successfully used to elucidate the disparlure biosynthetic pathway.     

Effect of transport time on welfare and meat quality in pigs

The purpose of this study was to determine the effects of transport duration on some welfare and meat quality parameters. For the study 144 pigs were used. One group of 72 animals was subjected to 15 min and the others to 3 h transport time. Blood from all animals was analysed in order to detect stress-susceptible pigs and assess pre-slaughter stress. Meat quality parameters were analysed from Longissimus thoracis and Semimembranosus muscles. It was concluded that under normal Spanish commercial conditions, pigs subjected to short transport showed a more intense stress response and poorer meat quality than pigs subjected to moderately long transport when they were immediately slaughtered on arrival at the slaughterhouse. Transport of 3 h might have allowed the animals to adapt to transport conditions and then could act as a resting period like a lairage time. The effect of transport time on welfare and meat quality parameters was more important than genotype and sex. Nevertheless, from the point of view of blood enzyme activities, genetically stress susceptible females transported for 3 h were more sensitive to muscle damage.     

Strong Paraconsistency and the Basic Constructive Logic for an Even Weaker Sense of Consistency

In a standard sense, consistency and paraconsistency are understood as the absence of any contradiction and as the absence of the ECQ (‘E contradictione quodlibet’) rule, respectively. The concepts of weak consistency (in two different senses) as well as that of F-consistency have been defined by the authors. The aim of this paper is (a) to define alternative (to the standard one) concepts of paraconsistency in respect of the aforementioned notions of weak consistency and F-consistency; (b) to define the concept of strong paraconsistency; (c) to build up a series of strongly paraconsistent logics; (d) to define the basic constructive logic adequate to a rather weak sense of consistency. All logics treated in this paper are strongly paraconsistent. All of them are sound and complete in respect a modification of Routley and Meyer’s ternary relational semantics for relevant logics (no logic in this paper is relevant).     

Combining shared control with variability over surface features: Effects on transfer test performance and task involvement

Positive effects of learner control decrease when learners do not perceive the control given to them, make suboptimal choices, or are cognitively overloaded by the amount of choice. This study proposes shared control (i.e., learners choose from a pre-selection of suitable tasks) over highly variable tasks to tackle these problems. Ninety-four students participated in a 2 × 2 factorial experiment with the factors control (system, shared) and variability of surface features (low, high). Results show superior effects on training performance, transfer test performance, and task involvement of shared control when learners can choose from pre-selected tasks with surface features that are different from the surface features of previous tasks.     

Computer-based feedback in linear algebra: Effects on transfer performance and motivation

Two studies investigated the effects on students' perceptions (Study 1) and learning and motivation (Study 2) of different levels of feedback in mathematical problems. In these problems, an error made in one step of the problem-solving procedure will carry over to the following steps and consequently to the final solution. Providing immediate feedback after an error is made could prevent such carry-over effects. Feedback given on all problem-solving steps was hypothesized to yield higher motivation and better learning than feedback on the final problem-solving step. Study 1 investigated students' perceptions of three feedback types: ‘on the final solution step’; ‘on all the solution steps at once’; and ‘on all the solution steps successively’. Feedback on all solutions steps was perceived by learners more positively than feedback on the final solution step. Study 2 investigated the learning and motivational effects of two types of feedback, namely, ‘feedback on the final solution step’ and ‘feedback on all the solution steps’. The hypotheses that feedback on all problem-solving steps would lead to more effective learning and higher motivation than feedback on the final solution step were confirmed. Our results support current efforts to implement step-wise feedback. The implications for further research and for the design of feedback are discussed.     

Why advice on task selection may hamper learning in on-demand education

In on-demand education, learners are required to plan their own learning trajectory by selecting suitable learning tasks. A positive effect on learning is expected when learners select tasks that help them fulfil their individual learning needs. However, the selection of suitable tasks is a difficult process for learners with little domain knowledge and suboptimal task-selection skills. A common solution for helping learners deal with on-demand education and develop domain-specific skills is to give them advice on task selection. In a randomized experiment, learners (N = 30) worked on learning tasks in the domain of system dynamics and received either advice or no advice on the selection of new learning tasks. Surprisingly, the no-advice group outperformed the advice group on a post-test measuring domain-specific skills. It is concluded that giving advice on task selection prevents learners from thinking about how the process of task selection works. The advice seems to supplant rather than support their considerations why they should perform the advised task, which results in negative effects on learning. Implications for future research on giving advice in on-demand education are discussed.     

Modelling dialogue as inter-action

In this paper we introduce a formal model of dialogue based on grammar systems theory: Conversational Grammar Systems (CGS). The model takes into account ideas from the study of human-human dialogue in order to define a flexible mechanism for coherent dialogues that may help in the design of effective and user-friendly computer dialogue systems. The main feature of the model is to present an action view of dialogue. CGS model dialogue as an inter-action, this is a sequence of acts performed by two or more agents in a common environment. We claim that CGS are able to model dialogue with a high degree of flexibility, which means that they are able to accept new concepts and modify rules, protocols and settings during the computation.     

Flightdeck and air traffic control collaboration evaluation (FACE): evaluating aviation communication in the laboratory and field

The challenge to anticipate the human factors impact of introducing new technologies into a safety critical environment can be addressed in a number of ways. This paper presents a research programme that utilised both laboratory- and field-based assessments to examine the way in which datalink and freeflight may affect the communication and collaboration between pilots, air traffic controllers, and other actors and artefacts in the flightdeck-air traffic control (ATC) joint cognitive system. An overview of the results from these studies is presented, and guidance is provided as to the likely situations in which this new technology is most likely to be successfully applied. In addition, the methodological approach of combining results from field and laboratory data is discussed.     

Plasma Lipid Profiling Contributes to Untangle the Complexity of Moyamoya Arteriopathy

Moyamoya arteriopathy (MA) is a rare cerebrovascular disorder characterized by ischemic/hemorrhagic strokes. The pathophysiology is unknown. A deregulation of vasculogenic/angiogenic/inflammatory pathways has been hypothesized as a possible pathophysiological mechanism. Since lipids are implicated in modulating neo-vascularization/angiogenesis and inflammation, their deregulation is potentially involved in MA. Our aim is to evaluate angiogenic/vasculogenic/inflammatory proteins and lipid profile in plasma of MA patients and control subjects (healthy donors HD or subjects with atherosclerotic cerebrovascular disease ACVD). Angiogenic and inflammatory protein levels were measured by ELISA and a complete lipidomic analysis was performed on plasma by mass spectrometry. ELISA showed a significant decrease for MMP-9 released in plasma of MA. The untargeted lipidomic analysis showed a cumulative depletion of lipid asset in plasma of MA as compared to HD. Specifically, a decrease in membrane complex glycosphingolipids peripherally circulating in MA plasma with respect to HD was observed, likely suggestive of cerebral cellular recruitment. The quantitative targeted approach demonstrated an increase in free sphingoid bases, likely associated with a deregulated angiogenesis. Our findings indicate that lipid signature could play a central role in MA and that a detailed biomarker profile may contribute to untangle the complex, and still obscure, pathogenesis of MA.