Dietary glycated protein modulates the colonic microbiota towards a more detrimental composition in ulcerative colitis patients and non-ulcerative colitis subjects

AIM: To investigate the effect of native, heated and glycated bovine serum albumin (BSA) on the ulcerative colitis (UC) and non-UC colonic microbiota in vitro. METHODS AND RESULTS: Continuous flow culture (CFC) models of the human colonic microbiota inoculated with faeces from UC and non-UC volunteers were maintained on BSA as growth substrate. Changes in bacterial populations and short-chain fatty acids were determined. UC and non-UC microbiota differed significantly in microbial populations, with elevated numbers of sulfate-reducing bacteria (SRB) and clostridia in the microbiota from UC patients. Compared with native BSA, glycated BSA modulated the gut microbiota of UC patients in vitro towards a more detrimental community structure with significant increases in putatively harmful bacteria (clostridia, bacteroides and SRB; P < 0.009) and decreases in dominant and putatively beneficial bacterial groups (eubacteria and bifidobacteria; P < 0.0004). The levels of beneficial short-chain fatty acids were significantly decreased by heated or glycated BSA, but were increased significantly by native BSA. CONCLUSION: The UC colonic microbiota maintained in CFC was significantly modified by glycated BSA. SIGNIFICANCE AND IMPACT OF THE STUDY: Results suggest that dietary glycated protein may impact upon the composition and activity of the colonic microbiota, an important environmental variable in UC.

Superovulation and embryo collection in nulliparous Boer goat does immunized against a recombinant ovine alpha-subunit inhibin

With the purpose of eliciting a superovulatory response, 12 adult nulliparous Boer goat does were actively immunized against a recombinant a-subunit of ovine inhibin (roIHN-alpha; two injections of 100 mg 4 weeks apart). Another 12 control Boer goat does were treated with physiological saline and acted as controls. One year later the immunized animals were boostered by the administration of another dose (100 mg) of the immunogen. Following treatment, blood samples were collected twice weekly for the periods of 16 and 12 weeks, respectively, to monitor the inhibin binding ability with the aid of a radio-tracer binding assay. Throughout the experiment, estrus detection was conducted twice daily with the aid of an aproned intact buck. From the first day after treatment to 48 h after standing estrus, ovarian activity was monitored daily by transrectal ultrasonography. On alternate estrous cycles, does were mated and 6 days later flushed transcervically to recover embryos. All goats treated with the roIHN-alpha produced antibodies reactive to the native bovine inhibin tracer-the titre increasing from 2.9 +/- 0.4 to a maximum of 21.9 +/- 2.9% binding after the second injection. The antibody titre gradually subsided over the next 16 weeks. The booster injection restored an elevated antibody titre (11.7 +/- 0.4%), which was maintained until the end of the sampling period 12 weeks later. In the control goats only trace amounts of antibody were recorded throughout the trial. In the roIHN-alpha-immunized goats the number of follicles reaching a diameter of > 4 mm was 14.6 +/- 1.2 per doe. A positive correlation was recorded between the follicle number and antibody titre (r=0.61; P < 0.01). The number of follicles ovulating per doe (6.9 +/- 0.7) followed the same tendency-however, the proportion decreased with increasing follicle numbers. A relatively weak correlation was recorded between the inhibin binding ability and number of ovulations (r=0.27; P < 0.05). In the control goats the majority (92%) of follicles exceeding 4 mm in diameter ovulated (2.5 +/- 0.1 follicles/doe). Embryo collection proved unsatisfactory (42% versus 39% recovery for immunized and control animals, respectively)-presumably because the uterine lumen of the nulliparous does was too narrow to permit effective flushing. In the group of immunized goats the occurrence of short estrous cycles (< 15 days) recorded was 34% versus only 6% in the controls. Overall, immunization of goats against roIHN-alpha led to an almost six-fold increase in number of ovarian follicles, a three-fold increase in ovulations and, despite the low recovery rate, a more than three-fold increase in ova or embryos recovered. It may be concluded that treatment of female goats with roIHN-alpha leads to an inhibin antibody response, accompanied by enhanced ovarian activity. The response was, however, accompanied by a large proportion of retained follicles and a high incidence of short estrous cycles. These problems need to be further investigated before rendering the method fit for application in embryo transfer programs in goats. (C) 2007 Elsevier B.V. All rights reserved.

Dietary glycated protein modulates the colonic microbiota towards a more detrimental composition in ulcerative colitis patients and non-ulcerative colitis subjects

Aim: To investigate the effect of native, heated and glycated bovine serum albumin (BSA) on the ulcerative colitis (UC) and non-UC colonic microbiota in vitro. Methods and Results: Continuous flow culture (CFC) models of the human colonic microbiota inoculated with faeces from UC and non-UC volunteers were maintained on BSA as growth substrate. Changes in bacterial populations and short-chain fatty acids were determined. UC and non-UC microbiota differed significantly in microbial populations, with elevated numbers of sulfate-reducing bacteria (SRB) and clostridia in the microbiota from UC patients. Compared with native BSA, glycated BSA modulated the gut microbiota of UC patients in vitro towards a more detrimental community structure with significant increases in putatively harmful bacteria (clostridia, bacteroides and SRB; P < 0.009) and decreases in dominant and putatively beneficial bacterial groups (eubacteria and bifidobacteria; P < 0.0004). The levels of beneficial short-chain fatty acids were significantly decreased by heated or glycated BSA, but were increased significantly by native BSA. Conclusion: The UC colonic microbiota maintained in CFC was significantly modified by glycated BSA. Significance and Impact of the Study: Results suggest that dietary glycated protein may impact upon the composition and activity of the colonic microbiota, an important environmental variable in UC.

Cross validation and segment support for stereo belief propagation

Typically, algorithms for generating stereo disparity maps have been developed to minimise the energy equation of a single image. This paper proposes a method for implementing cross validation in a belief propagation optimisation. When tested using the Middlebury online stereo evaluation, the cross validation improves upon the results of standard belief propagation. Furthermore, it has been shown that regions of homogeneous colour within the images can be used for enforcing the so-called "Segment Constraint". Developing from this, Segment Support is introduced to boost belief between pixels of the same image region and improve propagation into textureless regions.

An improved reliability Cuk based solar inverter with sliding mode control

Many photovoltaic inverter designs make use of a buck based switched mode power supply (SMPS) to produce a rectified sinusoidal waveform. This waveform is then unfolded by a low frequency switching structure to produce a fully sinusoidal waveform. The Cuk SMPS could offer advantages over the buck in such applications. Unfortunately the Cuk converter is considered to be difficult to control using classical methods. Correct closed loop design is essential for stable operation of Cuk converters. Due to these stability issues, Cuk converter based designs often require stiff low bandwidth control loops. In order to achieve this stable closed loop performance, traditional designs invariably need large, unreliable electrolytic capacitors. In this paper, an inverter with a sliding mode control approach is presented which enables the designer to make use of the Cuk converters advantages, while ameliorating control difficulties. This control method allows the selection of passive components based predominantly on ripple and reliability specifications while requiring only one state reference signal. This allows much smaller, more reliable non-electrolytic capacitors to be used. A prototype inverter has been constructed and results obtained which demonstrate the design flexibility of the Cuk topology when coupled with sliding mode control.

Electronic voting systems in undergraduate teaching

One of the major differences undergraduates experience during the transition to university is the style of teaching. In schools and colleges most students study key stage 5 subjects in relatively small informal groups where teacher–pupil interaction is encouraged and two-way feedback occurs through question and answer type delivery. On starting in HE students are amazed by the sizes of the classes. For even a relatively small chemistry department with an intake of 60-70 students, biologists, pharmacists, and other first year undergraduates requiring chemistry can boost numbers in the lecture hall to around 200 or higher. In many universities class sizes of 400 are not unusual for first year groups where efficiency is crucial. Clearly the personalised classroom-style delivery is not practical and it is a brave student who shows his ignorance by venturing to ask a question in front of such an audience. In these environments learning can be a very passive process, the lecture acts as a vehicle for the conveyance of information and our students are expected to reinforce their understanding by ‘self-study’, a term, the meaning of which, many struggle to understand. The use of electronic voting systems (EVS) in such situations can vastly change the students’ learning experience from a passive to a highly interactive process. This principle has already been demonstrated in Physics, most notably in the work of Bates and colleagues at Edinburgh.1 These small hand-held devices, similar to those which have become familiar through programmes such as ‘Who Wants to be a Millionaire’ can be used to provide instant feedback to students and teachers alike. Advances in technology now allow them to be used in a range of more sophisticated settings and comprehensive guides on use have been developed for even the most techno-phobic staff.

The evolution of indigenous contractors in Ghana

This paper provides some preliminary insights into the emergence and development of indigenous general contractors in Ghana. General contracting is the means by which an individual or organisation takes responsibility for supplying all of the materials, labour, equipment and services necessary for the construction of a project. Whereas the development of general contracting in places like the UK is well documented, the evolution of contractors in Ghana is not clearly articulated in the literature. Therefore, the main question in this paper is: How did indigenous contractors evolve in Ghana? To examine and analyze the research question, a literature review on similar developments elsewhere was first carried out. This was followed by discussions and unstructured interviews with experienced construction practitioners in Ghana most of whom were Quantity Surveyors. Most interviewees narrated their knowledge of contractor development in Ghana dating back to around 1945. From the explanations given, it was possible to develop a general understanding of the research question and to make a qualitative interpretation of the respondents’ comments and to draw some conclusions. General contractors emerged rapidly in the Gold Coast (now Ghana) shortly after World War II. Most were Italian master craftsmen in Ghana who were capitalized by the British colonial government to develop infrastructure in the Gold Coast following devastating effects of the war. Some of the indigenous people learned from the Italians and also established construction firms. Thus, general contracting in Ghana has a relatively short history in comparison to countries like Britain where the profession developed rapidly in the early part of the 19th century in response to the industrial revolution. Although they may possess sufficient technical expertise, many indigenous contractors in Ghana today lack the capacity to carry out major projects because of low capitalization and poor organisational structures. The current construction market in Ghana is dominated by foreign contractors. To become major players in the market, indigenous Ghanaian contractors should build strong organisational structures and pursue mergers and joint venturing to boost their financial, technical and managerial capacity.

Reducing contamination by exposure plus safety behaviour

Background and objectives: It has been proposed that the judicious use of safety behaviour can facilitate improvements in the acceptability of cognitive behaviour therapy (CBT). It was decided to explore the possibility of facilitating CBT by introducing a form of safety behaviour.We sought to assess the degree to which Exposure plus Safety Behaviour (E þ SB) is an effective intervention for contamination fears. Methods: A comparison was made between the effects of a control condition (Exposure and Response Prevention; ERP) and an experimental condition (Exposure plus Safety Behaviour; E þ SB) in which each exposure to a contaminant was followed by the use of a hygienic wipe in a sample of (n ¼ 80) undergraduate students. In session one, each participant touched a confirmed contaminant 20 times. After each exposure participants were asked to report their feelings of contamination, fear, disgust, and danger. In the second session, two weeks later, the same procedure was carried out for a further 16 trials. Results: The ERP and the E þ SB conditions both produced large, significant and stable reductions in contamination. Significant reductions in fear, danger and disgust were also reported in both conditions. Limitations: The treatment was provided to an analogue sample and over two sessions. Conclusions: The use of hygienic wipes, the safety behaviour used in this experiment, did not preclude significant reductions in contamination, disgust, fear and danger. If it is replicated and extended over a longer time-frame, this finding may enable practitioners to enhance the acceptability of cognitive behavioural treatments and boost their effectiveness.

Frozen tears I

Russell, J. [Ed., designer & authored chapter]. Including texts by Georges Bataille, Art & Language, Fabienne Audéoud, Dave Beech, Paul Buck, David Burrows, Ccru, Jake Chapman, John Cussans, johnny golding, Inventory, Martin Mcgeown, Lucy Mckenzie, Esther Planas, Graham Ramsay, John Russell, Clara Ursitti and Andrew Williamson. 800 pages.

Secondary school students’ epistemic insight into the relationships between science and religion – a preliminary enquiry

A number of previous studies have shown that there is a widespread view among young people that science and religion are opposed. In this paper, we suggest that it requires a significant level of what can be termed ‘epistemic insight’ to access the idea that some people see science and religion as compatible while others do not. To explore this further, we draw on previous work to devise a methodology to discover students’ thinking about apparent contradictions between scientific and religious explanations of the origins of the universe. In our discussion of the findings, we highlight that students’ epistemic insight in this context does seem in many cases to be limited and we outline some of the issues emerging from the study that seem to boost or limit students’ progress in this area.

Microcontroller-based peak current mode control using digital slope compensation

Microcontroller-based peak current mode control of a buck converter is investigated. The new solution uses a discrete time controller with digital slope compensation. This is implemented using only a single-chip microcontroller to achieve desirable cycle-by-cycle peak current limiting. The digital controller is implemented as a two-pole, two-zero linear difference equation designed using a continuous time model of the buck converter and a discrete time transform. Subharmonic oscillations are removed with digital slope compensation using a discrete staircase ramp. A 16 W hardware implementation directly compares analog and digital control. Frequency response measurements are taken and it is shown that the crossover frequency and expected phase margin of the digital control system match that of its analog counterpart.

Choosing the most suitable analogue redesign method for forward-type digital power converters

This work proposes a method to objectively determine the most suitable analogue redesign method for forward type converters under digital voltage mode control. Particular emphasis is placed on determining the method which allows the highest phase margin at the particular switching and crossover frequencies chosen by the designer. It is shown that at high crossover frequencies with respect to switching frequency, controllers designed using backward integration have the largest phase margin; whereas at low crossover frequencies with respect to switching frequency, controllers designed using bilinear integration have the largest phase margins. An accurate model of the power stage is used for simulation, and experimental results from a Buck converter are collected. The performance of the digital controllers is compared to that of the equivalent analogue controller both in simulation and experiment. Excellent correlation between the simulation and experimental results is presented. This work will allow designers to confidently choose the analogue redesign method which yields the greater phase margin for their application.

Systematic selection of analogue redesign method for forward-type digital power converters

This article proposes a systematic approach to determine the most suitable analogue redesign method to be used for forward-type converters under digital voltage mode control. The focus of the method is to achieve the highest phase margin at the particular switching and crossover frequencies chosen by the designer. It is shown that at high crossover frequencies with respect to switching frequency, controllers designed using backward integration have the largest phase margin; whereas at low crossover frequencies with respect to switching frequency, controllers designed using bilinear integration with pre-warping have the largest phase margins. An algorithm has been developed to determine the frequency of the crossing point where the recommended discretisation method changes. An accurate model of the power stage is used for simulation and experimental results from a Buck converter are collected. The performance of the digital controllers is compared to that of the equivalent analogue controller both in simulation and experiment. Excellent closeness between the simulation and experimental results is presented. This work provides a concrete example to allow academics and engineers to systematically choose a discretisation method.

Outward investments and productivity: evidence from European regions

Outward investments and productivity: evidence from European regions, Regional Studies. Using a novel data set on international investment projects, this paper builds measures of outward foreign direct investments (FDIs) for 262 regions of the European Union. This allows as estimation to be made of regressions of productivity growth over the 2007–11 period as a function of the number of FDIs. The number of outward FDIs in manufacturing activities is negatively associated with productivity growth in the home region, but investments in sales, distribution and marketing are associated with a boost in local productivity. This is driven especially by investments towards non-European Union locations. This evidence qualifies the fear of hollowing-out as a consequence of outward investments