2,999 research outputs found
Limits on the infrared photometric monitoring of brown dwarfs
Recent monitoring programs of ultra cool field M and L dwarfs (low mass stars
or brown dwarfs) have uncovered low amplitude photometric I-band variations
which may be associated with an inhomogeneous distribution of photospheric
condensates. Further evidence hints that this distribution may evolve on very
short timescales, specifically of order a rotation period or less. In an
attempt to study this behaviour in more detail, we have carried out a pilot
program to monitor three L dwarfs in the near infrared where these objects are
significantly brighter than at shorter wavelengths. We present a robust data
analysis method for improving the precision and reliability of infrared
photometry. No significant variability was detected in either the J or Km bands
in 2M1439 and SDSS1203 above a peak-to-peak amplitude of 0.04 mag (0.08 mag for
2M1112). The main limiting factor in achieving lower detection limits is
suspected to be second order extinction effects in the Earth's atmosphere, on
account of the very different colours of the target and reference stars.
Suggestions are given for overcoming such effects which should improve the
sensitivity and reliability of infrared variability searches.Comment: MNRAS, in press (9 pages
Functional Neural Plasticity and Associated Changes in Positive Affect After Compassion Training
The development of social emotions such as compassion is crucial for successful social interactions as well as for the maintenance of mental and physical health, especially when confronted with distressing life events. Yet, the neural mechanisms supporting the training of these emotions are poorly understood. To study affective plasticity in healthy adults, we measured functional neural and subjective responses to witnessing the distress of others in a newly developed task (Socio-affective Video Task). Participants' initial empathic responses to the task were accompanied by negative affect and activations in the anterior insula and anterior medial cingulate cortex—a core neural network underlying empathy for pain. Whereas participants reacted with negative affect before training, compassion training increased positive affective experiences, even in response to witnessing others in distress. On the neural level, we observed that, compared with a memory control group, compassion training elicited activity in a neural network including the medial orbitofrontal cortex, putamen, pallidum, and ventral tegmental area—brain regions previously associated with positive affect and affiliation. Taken together, these findings suggest that the deliberate cultivation of compassion offers a new coping strategy that fosters positive affect even when confronted with the distress of other
The Critical Target Audience: Communicating Water Conservation Behaviors to Critical Thinking Styles
Although water covers approximately 70% of the planet, only a fraction is fresh water, and even less is used as a major source of drinking water. With the continuous increase in the amount of water used in modern standards of living, the quantity of water available is decreasing. The public is beginning to understand water needs to be conserved and they must play a role in water conservation. While previous literature examined how the majority of messages were catered toward the cost-effectiveness of conserving water, this study proposed how using a specific audience attribute could affect behaviors. The purpose of the study was to determine if critical thinking style can be used in the development of future communication strategies to improve water conservation behaviors. The findings of this study provided evidence of a relationship between critical thinking style and the level of engagement in water conservation behaviors. Recommendations suggested targeting the two constructs of critical thinking style, information seekers and engagers, in two different ways. Since the seekers prefer to gather information by seeking the sources themselves, communicators should focus on developing quality information about water conservation and placing it in easily accessible communications channels for the information seeker. On the other hand, a different communications approach should be taken with the engagers, who prefer to learn through their environment. Communicators should focus on communicating to the engager through the environment in word-of-mouth situations using traditional means such as opinion leaders as well as social media
Water use in Florida: Examining Perceptions of Water use Based on Visual Images
Residents and decision makers often perceive information regarding water use differently. This is an issue in Florida where water quantity is a concern, and the distribution of accurate knowledge will be necessary to assist in effective conservation efforts. This study used two online surveys to gain insight into Florida residents’ and decision makers’ (county commissioners, county clerks and county managers) perceptions of water use based on visual images. Using non-probability opt-in sampling methods a total of 525 Florida residents’ responses were collected, and in a second survey 169 decision makers’ responses were collected. Respondents were asked to associate a specific water user, based on a visual, with high, moderate, or low water usage. A series of chi-square tests were used to compare and test for differences between Florida residents’ and decision makers’ perceptions, revealing that significant differences in perception did exist. The identification of these differences was used to develop recommendations for enhancing education and communication regarding water use
Identifying Advantages and Disadvantages of Variable Rate Irrigation – An Updated Review
Variable rate irrigation (VRI) sprinklers on mechanical move irrigation systems (center pivot or lateral move) have been commercially available since 2004. Although the number of VRI, zone or individual sprinkler, systems adopted to date is lower than expected there is a continued interest to harness this technology, especially when climate variability, regulatory nutrient management, water conservation policies, and declining water for agriculture compound the challenges involved for irrigated crop production. This article reviews the potential advantages and potential disadvantages of VRI technology for moving sprinklers, provides updated examples on such aspects, suggests a protocol for designing and implementing VRI technology and reports on the recent advancements. The advantages of VRI technology are demonstrated in the areas of agronomic improvement, greater economic returns, environmental protection and risk management, while the main drawbacks to VRI technology include the complexity to successfully implement the technology and the lack of evidence that it assures better performance in net profit or water savings. Although advances have been made in VRI technologies, its penetration into the market will continue to depend on tangible and perceived benefits by producers
Testing the Usability of Communication Materials through Heat Maps in Online Survey Platforms
Usability tests can be used to enhance the communication strategies of agricultural organizations as they identify the use and value of a communications tool from a target audience’s perspective. Further, online survey methodology has provided a place where communicators can gather information from a diverse target audience. One way communicators can create a usability test in online surveys is through the use of heat map questions. Heat map questions provide a platform where agricultural communication professionals and researchers can identify how well a target audience uses a communication material. By merging heat maps and value-based questions, researchers and communicators can evaluate the usability and value of a communication material. Heat maps allow agricultural communicators to evaluate communication materials such as websites and iers, gather users’ feedback and identify strategies to enhance agricultural communication materials. This article provides steps to incorporate heat map questions into online survey, tips for using heat map tests, and methods to interpret heat map results
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