Social Reinforcement and Diurnal Rhythms in Baboons

The frequency with which one monkey opened a door for two minutes of visual and physical contact with another monkey was examined as a function of several experimental procedures. In the first series of manipulations removal of the second monkey allowed a comparison between the effects of the social reinforcing object and the effects of the non-social stimuli incidental to delivery of the social reinforcer. During daily four-hour sessions, reinforcement rates (number of door openings/unit time) with a monkey in the adjacent cage averaged several times those when no monkey was in the adjacent cage. Removal of the second monkey did not significantly affect rates of food and water reinforcement, but removal of food and water contingencies did increase rates of door opening to an empty cage. Idiosyncratic factors contributed to above-zero rates when the cage was empty. For example, one subject's empty-cage rates were halved, and his amount of stereotyped rocking nearly stopped, by a wall placed next to the door. The existence of pertinent variables peculiar to the individual subject and to the particular apparatus directs attention to the necessity of control procedures. In the second set of conditions two baboons lived in the cages 24 hours a day and were under continuous illumination, as they had been for several months. During a short initial period when either monkey could open the door, and in a second longer period when only one could open the door, the monkeys had a very regular day length of approximately 14 hours, which remained synchronous with clock time. The experiment did not identify the pertinent elements entraining the monkeys' activities. This persisting alignment with clock time under reasonably stable conditions suggests that the entraining environmental stimuli were more subtle than those demonstrated in the literature. The monkeys also revealed a distinctive patterning of frequency of social contact as a function of time of day. The distribution had a midmorning peak, a midday low, and a minor afternoon peak, the same pattern recently documented as occurring in troops of wild baboons. This pattern was only barely noticeable in distributions from individual days, and became significant only when averaged across days. To a lesser degree, similar patterns were evident in distributions of food and water reinforcement rates. In the final set of procedures two levels of food deprivation, two levels of social deprivation, and two times of day were produced by alternating the subjects in morning and afternoon sessions, by conducting only morning or only afternoon sessions, and by pre-feeding and "pre-socializing" in a sequence designed to contrast the effect of one condition against another. Regardless of deprivation of social or other reinforcers, the subjects displayed a higher rate of social reinforcement in the mornings than in the afternoons. An early morning "pre-socializing" session slightly lowered the usual morning rate of social reinforcement, but preceding an afternoon session with a morning session, an early morning and a morning session, or by no session since the previous afternoon, had no effect on the afternoon social reinforcement rates. Independence of social reinforcement rates from variations in food deprivation, and low frequencies of eating with the door open implied that the presence of food did not appreciably affect rates of social reinforcement. These studies established social reinforcement under controlled laboratory conditions as a strong reinforcer capable of maintaining behavior over long periods of time, and elucidated a pertinent variable in social reinforcement, that of diurnal rhythms

A pilot study to elucidate and validate public health-related environmental effect estimates from statistical modelling of daily health outcome counts

Health Services Research Fund & Health Care and Promotion Fund: Research Dissemination Reports (Series 9)published_or_final_versio

Deconstructing Ihf-Mediated Inhibition of the Complex acs Promoter

acs encodes a high affinity enzyme that permits survival during carbon starvation. As befits a survival gene, its transcription is subject to complex regulation. Previously, the Wolfe lab reported that CRP activates acs transcription by binding tandem DNA sites located upstream of the major acsP2 promoter and that the nucleoid protein IHF binds three specific sites located just upstream. The most proximal site (IHF III) exhibits reduced transcription compared to the full-length promoter or to a construct lacking all three IHF sites. The goal of my research was to understand how IHF III inhibits CRP-dependent acs transcription. First, I helped define the minimal system required for this IHF-dependent inhibition, showing it requires the promoter-distal CRP site and an amino acid residue located within a surface determinant of CRP that interacts with RNAP. Surprisingly, for a Class III promoter, disruption of this surface determinant caused significant changes in the activity and structure of both the full-length promoter and the construct with the single proximal IHF site. My collaborator, Dr. Bianca Sclavi (Laboratoire de Biotechnologies et Pharmacologie génétique Appliquée, Paris, France) showed that occupancy of IHF III mediates formation of a stalled unproductive transcription complex. This work was published in Molecular Microbiology. I furthered this research, obtaining evidence that IHF III is actually a composite site consisting of two overlapping IHF sites that sit on opposing faces of the DNA helix. This composite appears to behave as a transcriptional regulatory switch. If IHF occupies one site, acs transcription occurs. If IHF occupies the opposing site, acs transcription is inhibited. Which site becomes occupied appears to involve occupancy of IHF II, which is located just upstream of IHF III. This work demonstrates that the typical textbook view bacterial transcription is overly simplistic. In fact, bacterial transcription can be quite complex

Temperature as a modifier of the effects of fine particulate matter on acute mortality in Hong Kong

Interactions between particulate matter with aerodynamic diameter less than or equal to 2.5 μm (PM2.5) and temperature on mortality have not been well studied, and results are difficult to synthesize. We aimed to assess modification of temperature on the association between PM2.5 and cause-specific mortality by stratifying temperature into low, medium, and high stratum in Hong Kong, using data from 1999 to 2011. The mortality effects of PM2.5 were stronger in low temperature stratum than those in high. The excess risk (%) per 10 μg/m3 increase in PM2.5 at lag 0–1 in low temperature stratum were 0.94% (95% confidence interval: 0.65, 1.24) for all natural, 0.88% (0.38, 1.37) for cardiovascular, and 1.15% (0.51, 1.79) for respiratory mortality. We found statistically significant interaction of PM2.5 and temperature between low and high temperature stratum for all natural mortality. Our results suggested that temperature might modify mortality effects of PM2.5 in Hong Kong.postprin

Accounting for Hysteresis in the Forward Kinematics of Nonlinearly-Routed Tendon-Driven Continuum Robots via a Learned Deep Decoder Network

Tendon-driven continuum robots have been gaining popularity in medical applications due to their ability to curve around complex anatomical structures, potentially reducing the invasiveness of surgery. However, accurate modeling is required to plan and control the movements of these flexible robots. Physics-based models have limitations due to unmodeled effects, leading to mismatches between model prediction and actual robot shape. Recently proposed learning-based methods have been shown to overcome some of these limitations but do not account for hysteresis, a significant source of error for these robots. To overcome these challenges, we propose a novel deep decoder neural network that predicts the complete shape of tendon-driven robots using point clouds as the shape representation, conditioned on prior configurations to account for hysteresis. We evaluate our method on a physical tendon-driven robot and show that our network model accurately predicts the robot's shape, significantly outperforming a state-of-the-art physics-based model and a learning-based model that does not account for hysteresis.Comment: 8 pages, 9 figures, Submitted to IEEE Robotics and Automation Letter

Toy gun eye injuries - eye protection needed Helsinki ocular trauma study

Purpose We report the epidemiology, findings, treatment, long-term outcome and use of resources for eye injuries caused by toy guns in southern Finland. Methods All new patients injured by toy guns in one year (2011-2012) and treated at Helsinki University Eye Hospital were included. Follow-ups occurred at 3 months and 5 years. Results Toy guns caused 15 eye traumas (1% of all eye traumas). Most patients were male (n = 14) and children aged under 16 years (n = 13). Toy guns involved were airsoft guns (n = 12), pea shooters (n = 2) and paintball (n = 1). Eleven patients did not use protective eyewear, and four patients discontinued their use during the game. Seven patients were not active participants in the game. Blunt ocular trauma was the primary diagnosis in 13 patients and corneal abrasion in two. Seven patients had retinal findings. In the 5-year follow-up, eight of 15 patients had abnormal ocular findings: three had artificial intraocular lens, two iridodialysis, and one each retinal plomb, mydriasis or iris tear. None had glaucoma. Seven patients had permanent subjective impairment due to pain, lowered visual acuity, blur or difficulty in focusing. Four patients needed seven operations. The number of outpatient visits was 90. One patient required hospitalization. Conclusion Toy guns cause serious eye traumas. No glaucoma was found. Proper use of toy guns and protective eyewear during the whole game should be emphasized to both players and bystanders. We recommend that in Finland the selling of airsoft guns be placed under the Firearms Act to make the hazards of airsoft guns known.Peer reviewe

Generation Y and sparkling wines: a cross-cultural perspective

The aim of this study was to investigate and compare the engagement of Generation Y consumers with champagne and sparkling wine across five Anglophone countries. A qualitative approach was adopted using focus groups with young consumers, including images and wine tasting as projective stimuli. There were significant trans-cultural similarities between consumption behaviour (sparkling wine is a women’s drink, and a separate category from still wine, and that they will ‘grow into’ drinking it) but also noticeable differences (responses to images and colours varied substantially, as did attitudes to price and the particular status of champagne). Research into the behaviour of Generation Y as a cohort needs to take account of cultural as much as generational context. However, as a qualitative study the findings need further quantitative validation. Marketers cannot view Generation Y as a single group; even within countries marketing strategies may need to be refined depending on where a product is being sold

Cascaded multicavity resonantly enhanced Mach-Zehnder modulator

Abstract—A resonantly enhanced modulator structure with cascaded multiple resonant cavities is proposed and analyzed. The microwave effective index of the electrode can be much higher than the optical index. Therefore, the electrode structure can be optimized for high modulation efficiency and high resonant enhancement. I