The effects of alcohol cue exposure on non-dependent drinkers' attentional bias for alcohol-related stimuli

Aims: The effects of university students’ habitual drinking practices and experimental alcohol cue exposure on their attentional bias for alcohol-related stimuli were assessed.Methods: Participants were exposed in vivo to either an alcoholic or non-alcoholic beverage immediately prior to completing a cognitively demanding emotional Stroop task that uses alcohol-related and control words as potential distractors.Results: Regression analyses indicated that, for participants who were low consumers of alcohol, neither level of habitual drinking, type of cue exposure, nor their interaction predicted attentional bias for the alcohol-related stimuli. For high consumers of alcohol who were exposed to the alcoholic beverage (but not those exposed to the non-alcoholic beverage), the amount of alcohol that participants habitually drank significantly predicted the degree of attentional bias.Conclusions: The results indicate that, among non-dependent drinkers (unlike alcohol-dependent participants), alcohol-related attentional bias is not a generalized phenomenon, but occurs only under a specific set of circumstances

Electromagnetic wave propagation in a magnetized laboratory plasma

Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science; and, Thesis (B.S.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1998.Includes bibliographical references (p. 60-61).by Michael Joseph Rowlands.B.S.M.Eng

Organic Farming in Wales 2003 - 2004

Organic Centre Wales (OCW) was originally formed to act as an information source for producers enquiring into organic farming; in our second phase, in response to changes in the sector, we have an increased remit on policy issues. It has been a busy time, seeing the production of a second Organic Action Plan, the implementation of the CAP reform and development work on agri-environment reforms. The year also saw the start of organic maintenance payments for farmers. This Annual Report contains accounts of the progress that has been made on many fronts during the last 12 months, particularly in market knowledge due to the research for the recently published report, 'Organic Food: understanding the consumer and increasing sales'. This information, together with continuing product development work, will enable Welsh organic producers to be proactive in building a solid consumer base

Using accelerometry to classify physical activity intensity in older adults:What is the optimal wear-site?

This study aimed to determine the optimal accelerometer wear-site specific cut-points for discrimination of the sedentary time, light physical activity and moderate-to-vigorous physical activity (MVPA) in older adults. Twenty-three adults (14 females) aged 55-77 years wore a GENEActiv accelerometer on their non-dominant wrist, dominant wrist, waist and dominant ankle whilst undertaking eight, five-minute bouts of activity: lay supine, seated reading, slow walking, medium walking, fast walking, folding laundry, sweeping and stationary cycling. VO2 was assessed concurrently using indirect calorimetry. Receiver-operating-characteristic (ROC) analyses were used to derive wear-site specific cut-points for classifying intensity. Indirect calorimetry indicated that being lay supine and seated reading were classified as sedentary (3 METs). Areas under ROC curves indicated that the classification of sedentary activity was good for the non-dominant wrist and excellent for all other wear sites. Classification of MVPA was excellent for the waist and ankle, good for the waist and poor for the dominant and non-dominant wrists. Overall, the ankle location performed better than in other locations. Ankle-worn accelerometry appears to provide the most suitable wear-site to discriminate between sedentary time and MVPA in older adults

Validation of the GENEA accelerometer

Purpose: The study aims were: 1) to assess the technical reliability and validity of the GENEA using a mechanical shaker; 2) to perform a GENEA value calibration to develop thresholds for sedentary and light-, moderate-, and vigorous-intensity physical activity; and 3) to compare the intensity classification of the GENEA with two widely used accelerometers. Methods: A total of 47 GENEA accelerometers were attached to a shaker and vertically accelerated, generating 15 conditions of varying acceleration and/or frequency. Reliability was calculated using SD and intrainstrument and interinstrument coefficients of variation, whereas validity was assessed using Pearson correlation with the shaker acceleration as the criterion. Next, 60 adults wore a GENEA on each wrist and on the waist (alongside an ActiGraph and RT3 accelerometer) while completing 10-12 activity tasks. A portable metabolic gas analyzer provided the criterion measure of physical activity. Analyses involved the use of Pearson correlations to establish criterion and concurrent validity and receiver operating characteristic curves to establish intensity cut points. Results: The GENEA demonstrated excellent technical reliability (CVintra = 1.4%, CVinter = 2.1%) and validity (r = 0.98, P < 0.001) using the mechanical shaker. The GENEA demonstrated excellent criterion validity using V̇O as the criterion (left wrist, r = 0.86; right wrist, r = 0.83; waist, r = 0.87), on par with the waist-worn ActiGraph and RT3. The GENEA demonstrated excellent concurrent validity compared with the ActiGraph (r = 0.92) and the RT3 (r = 0.97). The waist-worn GENEA had the greatest classification accuracy (area under the receiver operating characteristic curve (AUC) = 0.95), followed by the left (AUC = 0.93) and then the right wrist (AUC = 0.90). The accuracy of the waist-worn GENEA was virtually identical with that of the ActiGraph (AUC = 0.94) and RT3 (AUC = 0.95). CONCLUSION:: The GENEA is a reliable and valid measurement tool capable of classifying the intensity of physical activity in adults. © 2011 by the American College of Sports Medicine

Recovery of Bennu's Orientation for the OSIRIS-REx Mission: Implications for the Spin State Accuracy and Geolocation Errors

The goal of the OSIRIS-REx mission is to return a sample of asteroid material from Near-Earth Asteroid (101955) Bennu. The role of the navigation and fight dynamics team is critical for the spacecraft to execute a precisely planned sampling maneuver over a specifically-selected landing site. In particular, the orientation of Bennu needs to be recovered with good accuracy during orbital operations to contribute as small an error as possible to the landing error budget. Although Bennu is well characterized from Earth-based radar observations, its orientation dynamics are not sufficiently known to exclude the presence of a small wobble. To better understand this contingency and evaluate how well the orientation can be recovered in the presence of a large 1 degree wobble, we conduct a comprehensive simulation with the NASA GSFC GEODYN orbit determination and geodetic parameter estimation software. We describe the dynamic orientation modeling implemented in GEODYN in support of OSIRIS-REx operations, and show how both altimetry and imagery data can be used as either undifferenced (landmark, direct altimetry) or differenced (image crossover, altimetry crossover) measurements. We find that these two different types of data contribute differently to the recovery of instrument pointing or planetary orientation. When upweighted, the absolute measurements help reduce the geolocation errors, despite poorer astrometric (inertial) performance. We find that with no wobble present, all the geolocation requirements are met. While the presence of a large wobble is detrimental, the recovery is still reliable thanks to the combined use of altimetry and imagery data