Is it possible to dissociate ‘liking’ and ‘wanting’ for foods in humans? A novel experimental procedure

Berridge's model (e.g. [Berridge KC. Food reward: Brain substrates of wanting and liking. Neurosci Biobehav Rev 1996;20:1–25.; Berridge KC, Robinson T E. Parsing reward. Trends Neurosci 2003;26:507–513.; Berridge KC. Motivation concepts in behavioral neuroscience. Physiol Behav 2004;81:179–209]) outlines the brain substrates thought to mediate food reward with distinct ‘liking’ (hedonic/affective) and ‘wanting’ (incentive salience/motivation) components. Understanding the dual aspects of food reward could throw light on food choice, appetite control and overconsumption. The present study reports the development of a procedure to measure these processes in humans. A computer-based paradigm was used to assess ‘liking’ (through pleasantness ratings) and ‘wanting’ (through forced-choice photographic procedure) for foods that varied in fat (high or low) and taste (savoury or sweet). 60 participants completed the program when hungry and after an ad libitum meal. Findings indicate a state (hungry–satiated)-dependent, partial dissociation between ‘liking’ and ‘wanting’ for generic food categories. In the hungry state, participants ‘wanted’ high-fat savoury > low-fat savoury with no corresponding difference in ‘liking’, and ‘liked’ high-fat sweet > low-fat sweet but did not differ in ‘wanting’ for these foods. In the satiated state, participants ‘liked’, but did not ‘want’, high-fat savoury > low-fat savoury, and ‘wanted’ but did not ‘like’ low-fat sweet > high-fat sweet. More differences in ‘liking’ and ‘wanting’ were observed when hungry than when satiated. This procedure provides the first step in proof of concept that ‘liking’ and ‘wanting’ can be dissociated in humans and can be further developed for foods varying along different dimensions. Other experimental procedures may also be devised to separate ‘liking’ and ‘wanting’.

Assessment of oral proficiency in EAP programs : a case for pair interaction

Reliability and validity in the testing of spoken language are essential in order to assess learners' English language proficiency as evidence of their readiness to begin courses in tertiary institutions. Research has indicated that the task chosen to elicit language samples can have a marked effect on both the nature of the interaction, including the power differential, and assessment, raising the issue of ethics. This exploratory studey, with a group of 32 students from the Peoples's Republic of China preparing for tertiary study in Singapore, compares test-takers' reactions to the use of an oral proficiency interview and a pair interaction.

Artful shaping : the ethics of fictionalising oral history

The paper documents the development of an ethical framework for my current PhD project. I am a practice-led researcher with a background in creative writing. My project invovles conducting a number of oral history interviews with individuals living in Brisbane, Queensland, Australia. I use the interviews to inform a novel set in Brisbane. In doing so, I hope to provide a lens into a cultural and historical space by creating a rich, textured and vivid narrative while still retaining some of the essential aspects of the oral history. While developing a methodology for fictionalising these oral histories, I have encountered a derserve range of ethical issues. In particular I have had to confront my role as a writer and researcher working with other people’s stories. In order to grapple with the complex ethics of such an engagment, I examine the devices and stratedgies employed by other creative practioners working in similar fields. I focus chielfy on Miguel Barnet’s Biography of a Runaway Slave (published in English in 1968) Dave Eggers’What is the what: The autobiography of Valentino Achek Deng, a novel (2005) in order to understand the complex processes of mediation invloved in the artful shaping of oral histories. The paper explores how I have confronted and resolved ethical considerations in my theoretical and creative work.

Effects of an acute α-lactalbumin manipulation on mood and food hedonics in high- and low-trait anxiety individuals

Serotonergic hypofunction is associated with a depressive mood state, an increased drive to eat and preference for sweet (SW) foods. High-trait anxiety individuals are characterised by a functional shortage of serotonin during stress, which in turn increases their susceptibility to experience a negative mood and an increased drive for SW foods. The present study examined whether an acute dietary manipulation, intended to increase circulating serotonin levels, alleviated the detrimental effects of a stress-inducing task on subjective appetite and mood sensations, and preference for SW foods in high-trait anxiety individuals. Thirteen high- (eleven females and two males; anxiety scores 45·5 (sd 5·9); BMI 22·9 (sd 3·0)kg/m2) and twelve low- (ten females and two males; anxiety scores 30·4 (sd 4·8); BMI 23·4 (sd 2·5) kg/m2) trait anxiety individuals participated in a placebo-controlled, two-way crossover design. Participants were provided with 40 g α-lactalbumin (LAC; l-tryptophan (Trp):large neutral amino acids (LNAA) ratio of 7·6) and 40 g casein (placebo) (Trp:LNAA ratio of 4·0) in the form of a snack and lunch on two test days. On both the test days, participants completed a stress-inducing task 2 h after the lunch. Mood and appetite were assessed using visual analogue scales. Changes in food hedonics for different taste and nutrient combinations were assessed using a computer task. The results demonstrated that the LAC manipulation did not exert any immediate effects on mood or appetite. However, LAC did have an effect on food hedonics in individuals with high-trait anxiety after acute stress. These individuals expressed a lower liking (P = 0·012) and SW food preference (P = 0·014) after the stressful task when supplemented with LAC.

Analytical modeling and sensitivity analysis for travel time estimation on signalized urban networks

This paper presents a model for estimation of average travel time and its variability on signalized urban networks using cumulative plots. The plots are generated based on the availability of data: a) case-D, for detector data only; b) case-DS, for detector data and signal timings; and c) case-DSS, for detector data, signal timings and saturation flow rate. The performance of the model for different degrees of saturation and different detector detection intervals is consistent for case-DSS and case-DS whereas, for case-D the performance is inconsistent. The sensitivity analysis of the model for case-D indicates that it is sensitive to detection interval and signal timings within the interval. When detection interval is integral multiple of signal cycle then it has low accuracy and low reliability. Whereas, for detection interval around 1.5 times signal cycle both accuracy and reliability are high.

TCSC control design for transient stability improvement of a multi-machine power system using trajectory sensitivity

This paper discusses the effects of thyristor controlled series compensator (TCSC), a series FACTS controller, on the transient stability of a power system. Trajectory sensitivity analysis (TSA) has been used to measure the transient stability condition of the system. The TCSC is modeled by a variable capacitor, the value of which changes with the firing angle. It is shown that TSA can be used in the design of the controller. The optimal locations of the TCSC-controller for different fault conditions can also be identified with the help of TSA. The paper depicts the advantage of the use of TCSC with a suitable controller over fixed capacitor operation.

Sensitivity of the lane change test as a measure of in-vehicle system demand

The Lane Change Test (LCT) is one of the growing number of methods developed to quantify driving performance degradation brought about by the use of in-vehicle devices. Beyond its validity and reliability, for such a test to be of practical use, it must also be sensitive to the varied demands of individual tasks. The current study evaluated the ability of several recent LCT lateral control and event detection parameters to discriminate between visual-manual and cognitive surrogate In-Vehicle Information System tasks with different levels of demand. Twenty-seven participants (mean age 24.4 years) completed a PC version of the LCT while performing visual search and math problem solving tasks. A number of the lateral control metrics were found to be sensitive to task differences, but the event detection metrics were less able to discriminate between tasks. The mean deviation and lane excursion measures were able to distinguish between the visual and cognitive tasks, but were less sensitive to the different levels of task demand. The other LCT metrics examined were less sensitive to task differences. A major factor influencing the sensitivity of at least some of the LCT metrics could be the type of lane change instructions given to participants. The provision of clear and explicit lane change instructions and further refinement of its metrics will be essential for increasing the utility of the LCT as an evaluation tool.

Does physical protection of soil organic matter attenuate temperature sensitivity?

Global climate change may induce accelerated soil organic matter (SOM) decomposition through increased soil temperature, and thus impact the C balance in soils. We hypothesized that compartmentalization of substrates and decomposers in the soil matrix would decrease SOM sensitivity to temperature. We tested our hypothesis with three short-term laboratory incubations with differing physical protection treatments conducted at different temperatures. Overall, CO2 efflux increased with temperature, but responses among physical protection treatments were not consistently different. Similar respiration quotient (Q(10)) values across physical protection treatments did not support our original hypothesis that the largest Q(10) values would be observed in the treatment with the least physical protection. Compartmentalization of substrates and decomposers is known to reduce the decomposability of otherwise labile material, but the hypothesized attenuation of temperature sensitivity was not detected, and thus the sensitivity is probably driven by the thermodynamics of biochemical reactions as expressed by Arrhenius-type equations.

Experimental warming shows that decomposition temperature sensitivity increases with soil organic matter recalcitrance

Soil C decomposition is sensitive to changes in temperature, and even small increases in temperature may prompt large releases of C from soils. But much of what we know about soil C responses to global change is based on short-term incubation data and model output that implicitly assumes soil C pools are composed of organic matter fractions with uniform temperature sensitivities. In contrast, kinetic theory based on chemical reactions suggests that older, more-resistant C fractions may be more temperature sensitive. Recent research on the subject is inconclusive, indicating that the temperature sensitivity of labile soil organic matter (OM) decomposition could either be greater than, less than, or equivalent to that of resistant soil OM. We incubated soils at constant temperature to deplete them of labile soil OM and then successively assessed the CO2-C efflux in response to warming. We found that the decomposition response to experimental warming early during soil incubation (when more labile C remained) was less than that later when labile C was depleted. These results suggest that the temperature sensitivity of resistant soil OM pools is greater than that for labile soil OM and that global change-driven soil C losses may be greater than previously estimated.

Sensitivity of organic matter decomposition to warming varies with its quality

The relationship between organic matter (OM) lability and temperature sensitivity is disputed, with recent observations suggesting that responses of relatively more resistant OM to increased temperature could be greater than, equivalent to, or less than responses of relatively more labile OM. This lack of clear understanding limits the ability to forecast carbon (C) cycle responses to temperature changes. Here, we derive a novel approach (denoted Q(10-q)) that accounts for changes in OM quality during decomposition and use it to analyze data from three independent sources. Results from new laboratory soil incubations (labile Q(10-q)=2.1 +/- 0.2; more resistant Q(10-q)=3.8 +/- 0.3) and reanalysis of data from other soil incubations reported in the literature (labile Q(10-q)=2.3; more resistant Q(10-q)=3.3) demonstrate that temperature sensitivity of soil OM decomposition increases with decreasing soil OM lability. Analysis of data from a cross-site, field litter bag decomposition study (labile Q(10-q)=3.3 +/- 0.2; resistant Q(10-q)=4.9 +/- 0.2) shows that litter OM follows the same pattern, with greater temperature sensitivity for more resistant litter OM. Furthermore, the initial response of cultivated soils, presumably containing less labile soil OM (Q(10-q)=2.4 +/- 0.3) was greater than that for undisturbed grassland soils (Q(10-q)=1.7 +/- 0.1). Soil C losses estimated using this approach will differ from previous estimates as a function of the magnitude of the temperature increase and the proportion of whole soil OM comprised of compounds sensitive to temperature over that temperature range. It is likely that increased temperature has already prompted release of significant amounts of C to the atmosphere as CO2. Our results indicate that future losses of litter and soil C may be even greater than previously supposed.

A story worth telling : putting oral history and digital collections online in cultural institutions

Digital platforms in cultural institutions offer exciting opportunities for oral history and digital storytelling that can augment and enrich traditional collections. The way in which cultural institutions allow access to the public is changing dramatically, prompting substantial expansions of their oral history and digital story holdings. In Queensland, Australia, public libraries and museums are becoming innovative hubs of a wide assortment of collections that represent a cross-section of community groups and organisations through the integration of oral history and digital storytelling. The State Library of Queensland (SLQ) features digital stories online to encourage users to explore what the institution has in the catalogue through their website. Now SLQ also offers oral history interviews online, to introduce users to oral history and other components of their collections,- such as photographs and documents to current, as well as new users. This includes the various departments, Indigenous centres and regional libraries affiliated with SLQ statewide, who are often unable to access the materials held within, or even full information about, the collections available within the institution. There has been a growing demand for resources and services that help to satisfy community enthusiasm and promote engagement. Demand increases as public access to affordable digital media technologies increases, and as community or marginalised groups become interested in do it yourself (DIY) history; and SLQ encourages this. This paper draws on the oral history and digital story-based research undertaken by the Queensland University of Technology (QUT) for the State Library of Queensland including: the Apology Collection: The Prime Minister’s apology to Australia’s Indigenous Stolen Generation; Five Senses: regional Queensland artists; Gay history of Brisbane; and The Queensland Business Leaders Hall of Fame.

Indentation size effect and strain rate sensitivity of nanocrystalline Mg-Al alloys

Deformation Behaviour of microcrystalline (mc) and nanocrystalline (nc) Mg-5%Al alloys produced by hot extrusion of ball-milled powders were investigated using instrumented indentation tests. The hardness values of the mc and nc metals exhibited indentation size effect (ISE), with nc alloys showing weaker ISE. The highly localized dislocation activities resulted in a small activation volume, hence enhanced strain rate sensitivity. Relative higher strain rate sensitivity and the negative Hall-Petch Relationship suggested the increasingly important role of grain boundary mediated mechanisms when the grain size decreased to nanometer region.

Oral fingolimod for relapsing-remitting multiple sclerosis

Background: Most people with multiple sclerosis have the relapsing-remitting type. Objective/methods: The objective was to evaluate two clinical trials of fingolimod in relapsing multiple sclerosis. Results: FREEDOMS (FTY720 Research Evaluation Effects of Daily Oral therapy in Multiple Sclerosis), a Phase III placebo-controlled trial, showed that fingolimod (0.5 or 1.25 mg) reduced the relapse rate and disability in multiple sclerosis, compared to placebo. Fingolimod (0.5 or 1.25 mg) has been compared to interferon β-1a in a Phase III clinical trial (TRANSFORMS; Trial Assessing Injectable Interferon versus FTY720 Oral in Relapsing-Remitting Multiple Sclerosis) and shown to be more efficacious than interferon β-1a in reducing relapse rates. However, fingolimod did increase the risk of infections and skin cancers. Conclusions: Only the lower dose of fingolimod (0.5 mg), which possibly has less toxicity, should be considered for prevention of relapses in relapsing-remitting multiple sclerosis.