Hearing and Echolocation in the Australian Grey Swiftlet, Collocalia Spodiopygia

The frequency sensitivity of hearing in the grey swiftlet, Collocalia spodiopygia, was determined by neuronal recordings from the auditory midbrain (MLD). The most sensitive best frequency response thresholds occurred between 0.8 and 4.7 kHz, with the upper frequency limit near 6 kHz. Spectral analysis of echolocation click pairs revealed energy peaks between 3.0 and 8.0kHz for the foreclick, compared to 4.0-6.0 kHz for the principal click. The relationship between good hearing sensitivity and click energy peaks in the swiftlet extends about an octave higher than it does in the oilbird (Steatornis caripensis)

Modeling the H2S Concentrations Affected by Shelterbelts Downwind from a Swine Facility

Odor from swine facilities can be a nuisance to the nearby residences and communities. Shelterbelts have been shown to positively impact the downwind air quality, but the impacts are dependent on wind speed and direction, and shelterbelt configuration. The first objective of this research was to develop an empirical model of shelterbelt-induced hydrogen sulfide (H2S) concentration reductions as a function of horizontal distance beyond a swine facility, based on data from a previous study by Hofer (2009). The Hofer (2009) study measured H2S concentrations at a swine facility at four discrete distances beyond the barn (55, 246, 510, and 805 m), two measurement heights (1 and 5.5 m), and with four shelterbelt configurations (no shelterbelt, 1-row, 2-row and 3-row). Data from this study was sorted using a data selection criteria process, resulting in 10 potential regression models. Each regression model was compared to a Computational Fluid Dynamics (CFD) model that was developed by Taylor and Starke (2006), using correlation, Normalized Mean Square Error (NMSE), and line of regression analyses. While the Hofer (2009) research measured H2S, the Taylor and Starke model (2006) described odor. In this research, H2S was considered a measure of odor. A single regression model was selected using a two-step selection process with the correlation, NMSE, and line of regression values. The regression model, y = 5.7408 * x-0.48, where y is the percent H2S reduction caused by the shelterbelt and x is the distance from the barn measured in meters, was selected. The second objective of this research was to incorporate this empirical model into the South Dakota Odor Footprint Tool (SDOFT) version 4.0. The SDOFT was revised to allow user input of shelterbelts located on one or more sides of the facility. The regression model was also incorporated into the SDOFT to create revised odor annoyance-free setbacks and footprint graphs affected by shelterbelts. A demonstration of odor annoyance-free setbacks and footprint graphs for different typical swine facilities with or without shelterbelts was completed. These demonstration sites illustrate that shelterbelts have greater effect on odor closer to the shelterbelt, with only about a 20% reduction at 1,000 m downwind from the facility

Quantitative Aspects of the Computation Performed by Visual Cortex in the Cat, With a Note on a Function of Lateral Inhibition

Work reported herein was conducted at the Artificial Intelligence Laboratory, a Massachusetts Institute of Technology research program supported in part by the Advanced Research Projects Agency of the Department of Defense and monitored by the Office of Naval Research under Contract Number N00014-70-A-0362-0005. Working Papers are informal papers intended for internal use.A quantitative summary is given of the computation that is performed by visual cortex in the cat. Part of this computation seems to be achieved using a sample-and-average technique; some quantitative features of this technique are briefly set out.MIT Artificial Intelligence Laborator

Kainic acid-induced eye enlargement in chickens: differential effects on anterior and posterior segments

Intravitreal injections of kainic acid were used to examine the significance of normal retinal activity for eye growth in chickens, this acid being chosen because of its known, selective neurotoxic effects on cells in the chicken retina. A 6 nmole dose of kainic significantly reduces amacrine cell numbers when used in very young chickens, while higher doses of kainic acid also affect bipolar and horizontal cell numbers. The effects of intravitreal injection of kainic acid on eye growth were assessed 4 weeks after treatment. A 200 nmole dose of kainic acid, used with day-old and 14-day-old chickens, had opposing effects on the anterior and posterior segments of the eye; while growth of the anterior segment was inhibited, the posterior segment was enlarged, predominantly in the equatorial direction. A 20 nmole dose of this acid similarly affected growth in 14-day-old chickens, but in day-old chickens, the anterior segment was also enlarged and the overall eye enlargement had an axial bias. Myopia was the most common refractive error associated with both patterns of development. A 2 nmole dose of kainic acid was without effect on eye growth. Parallels are drawn between these eye enlargement phenomena and those described in chickens whose visual environments have been manipulated. Our results indicate that normal retinal activity is fundamental to normal eye growth in chickens, and furthermore, that growth of the anterior and posterior segments of the chicken eye are independently regulated

Factors Associated with Poly Drug Use in Adolescents

Poly drug use in adolescents represents a significant public health issue, heightening risk for abuse, dependency, and a variety of short- and long-term psychological, psychosocial, and health consequences. However, past studies have typically examined just one or two substances in isolation and there is a lack of research that has comprehensively examined possible predictors of poly drug use in adolescents. To inform the development of comprehensive prevention programs that can simultaneously target multiple substances, the present study sought to identify psychological, environmental, and demographic factors that are most strongly associated with alcohol, tobacco, and cannabis poly drug use. Adolescents aged 15 to 17 years (n = 1661; 50.9% male) completed a survey on their use of alcohol, tobacco, and cannabis over the last 30 days. Various psychological, environmental, and demographic factors were also assessed. Weighted multiple-level logistic regression was conducted to assess the factors associated with poly drug use. In total, 20.3% of respondents had used at least one substance, 6.7% reported using two substances, and 3.3% reported using all three substances. The most common combined pattern of use was alcohol and tobacco, followed by alcohol and cannabis. Several factors emerged as significant, with conduct problems, depression, and the school environment accounting for the most variance. Specific psychological and environmental factors appear to be particularly important domains to target in adolescent substance use prevention programs. Early identification of adolescent depression and conduct problems and the development of programs that address these symptoms in youth may be effective approaches to delaying or preventing poly drug use in this population

The Salience of Vomiting in Teenagers Binge Drinking Intentions

Binge drinking among Australian teenagers has been identified as a serious health issue. Unfortunately, efforts to date to address this problem have been largely ineffective. It has been suggested that using images of teenagers vomiting in social marketing campaigns isn’t effective because vomiting is viewed as a positive outcome due its ability to signify a ‘big night’. The present study accessed online information posted by Australian teenagers to explore alcohol-related beliefs and behaviours that are reported online. A thematic analysis of the blogs suggests that for many Australian teenagers vomiting is still a deterrent to heavy drinking, and that they may be turning to illicit drugs to achieve an altered mental state with a lower risk of vomiting

Electroreception In monotremes

I will briefly review the history of the bill sense of the platypus, a sophisticated combination of electroreception and mechanoreception that coordinates information about aquatic prey provided from the bill skin mechanoreceptors and electroreceptors, and provide an evolutionary account of electroreception in the three extant species of monotreme (and what can be inferred of their ancestors). Electroreception in monotremes is compared and contrasted with the extensive body of work an electric fish, and an account of the central mechanoreceptive and electroreceptive input In the somatosensory neocortex of the platypus, where sophisticated calculations seem to enable a complete three-dimensional fix on prey, is given

The golden circle: A way of arguing and acting about technology in the London ambulance service

This paper analyses the way in which the London Ambulance Service recovered from the events of October 1992, when it implemented a computer-aided despatch system (LASCAD) that remained in service for less than two weeks. It examines the enactment of a programme of long-term organizational change, focusing on the implementation of an alternative computer system in 1996. The analysis in this paper is informed by actor-network theory, both by an early statement of this approach developed by Callon in the sociology of translation, and also by concepts and ideas from Latour’s more recent restatement of his own position. The paper examines how alternative interests emerged and were stabilized over time, in a way of arguing and acting among key players in the change programme, christened the Golden Circle. The story traces four years in the history of the London Ambulance Service, from the aftermath of October 1992 through the birth of the Golden Circle to the achievement of National Health Service (NHS) trust status. LASCAD was the beginning of the story, this is the middle, an end lies in the future, when the remaining elements of the change programme are enacted beyond the Golden Circle