Grid firing fields have been proposed as a neural substrate for spatial localisation in general or for path integration in particular. To distinguish these possibilities, we investigate firing of grid and non-grid cells in the mouse medial entorhinal cortex during a location memory task. We find that grid firing can either be anchored to the task environment, or can encode distance travelled independently of the task reference frame.
View Article and Find Full Text PDFNeurons in the retrohippocampal cortices play crucial roles in spatial memory. Many retrohippocampal neurons have firing fields that are selectively active at specific locations, with memory for rewarded locations associated with reorganization of these firing fields. Whether this is the sole strategy for representing spatial memories is unclear.
View Article and Find Full Text PDFPhilos Trans A Math Phys Eng Sci
November 2021
Agriculture is the largest single source of global anthropogenic methane (CH) emissions, with ruminants the dominant contributor. Livestock CH emissions are projected to grow another 30% by 2050 under current policies, yet few countries have set targets or are implementing policies to reduce emissions in absolute terms. The reason for this limited ambition may be linked not only to the underpinning role of livestock for nutrition and livelihoods in many countries but also diverging perspectives on the importance of mitigating these emissions, given the short atmospheric lifetime of CH.
View Article and Find Full Text PDFDietary transitions, such as eliminating meat consumption, have been proposed as one way to reduce the climate impact of the global and regional food systems. However, it should be ensured that replacement diets are indeed nutritious and that climate benefits are accurately accounted for. This study uses New Zealand food consumption as a case study for exploring the cumulative climate impact of adopting the national dietary guidelines and the substitution of meat from hypothetical diets.
View Article and Find Full Text PDFMicrobolometers are the dominant technology for uncooled thermal imaging; however, devices based on a direct retardation measurement of a liquid crystal (LC) transducer pixel have been shown to have comparable sensitivity. In this paper, an approach for increasing LC transducer sensitivity utilizing an etalon structure is considered. A detailed design for an LC resonant cavity between dielectric mirrors is proposed and the performance is evaluated numerically.
View Article and Find Full Text PDFIn this work, the detailed studies of surface polymerization stabilizing liquid crystal formed on an azodye sublayer are presented. The surface localized stabilization is obtained by free-radical polymerization of a dilute solution of a bi-functional reactive monomer (RM) in a liquid crystal (LC) solvent. To optimize the process for surface localized stabilization, we investigate the effects of several process parameters including RM concentration in LC hosts, the types of materials (either RM or LC), the photo-initiator (PI) concentration, ultra-violet (UV) polymerization intensity, and the UV curing temperature.
View Article and Find Full Text PDFGlob Chang Biol
April 2018
Agriculture directly contributes about 10%-12% of current global anthropogenic greenhouse gas emissions, mostly from livestock. However, such percentage estimates are based on global warming potentials (GWPs), which do not measure the actual warming caused by emissions and ignore the fact that methane does not accumulate in the atmosphere in the same way as CO . Here, we employ a simple carbon cycle-climate model, historical estimates and future projections of livestock emissions to infer the fraction of actual warming that is attributable to direct livestock non-CO emissions now and in future, and to CO from pasture conversions, without relying on GWPs.
View Article and Find Full Text PDFFeeding 9-10 billion people by 2050 and preventing dangerous climate change are two of the greatest challenges facing humanity. Both challenges must be met while reducing the impact of land management on ecosystem services that deliver vital goods and services, and support human health and well-being. Few studies to date have considered the interactions between these challenges.
View Article and Find Full Text PDFBackground: Commercialization of a closed-loop artificial pancreas system that employs continuous subcutaneous insulin infusion and interstitial fluid glucose sensing has been encumbered by state-of-the-art technology. Continuous glucose monitoring (CGM) devices with improved accuracy could significantly advance development efforts. However, the current accuracy of CGM devices might be adequate for closed-loop control.
View Article and Find Full Text PDFBackground: Rural trauma victims often require prolonged transport by s with limited scopes of practice. We evaluated the impact of telemedicine (TM) to a moving ambulance on outcomes in simulated trauma patients.
Methods: This is an institutional review board approved, prospective double-blind study.
Expert visual guidance (EVG) is computer assistance that displays to the examiner how the image plane moves towards (or away from) a desired anatomical location as the ultrasound probe is manipulated over the patient's body. We tested whether EVG by a remote expert could assist inexperienced examiners in acquiring abdominal ultrasound images. The inexperienced examiners were 20 medical students, who were randomly assigned to verbal instruction alone (Group 1) or to EVG (Group 2).
View Article and Find Full Text PDFEmergency healthcare systems in rural communities often have limited access to experienced trauma and emergency physicians. Advanced telecommunication technologies may offer an opportunity to help meet this need. We evaluated healthcare providers' satisfaction with the audio and visual components of an existing telemedicine system, and asked them whether emergency medical services (EMS) personnel could be supported via telemedicine guidance, using video laryngoscopy and ultrasonography, during vulnerable transport periods.
View Article and Find Full Text PDFKeppler et al. (2006, Nature 439, 187-191) showed that plants produce methane (CH) in aerobic environments, leading Lowe (2006, Nature 439, 148-149) to postulate that in countries such as New Zealand, where grazed pastures have replaced forests, the forests could have produced as much CH as the ruminants currently grazing these areas. Estimating CH emissions from up to 85 million ruminants in New Zealand is challenging and, for completeness, the capacity of forest and pastoral soils to oxidise CH should be included.
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