Circling in on convective organization

Cold pools (CPs) contribute to convective organization. However, it is unclear by which mechanisms organization occurs. By using a particle method to track CP gust fronts in large eddy simulations, we characterize the basic collision modes between CPs. Our results show that CP interactions, where three expanding gust fronts force an updraft, are key at triggering new convection. Using this, we conceptualize CP dynamics into a parameter‐free mathematical model: circles expand from initially random points in space. Where two expanding circles collide, a stationary front is formed. However, where three expanding circles enclose a single point, a new expanding circle is seeded. This simple model supports three fundamental features of CP dynamics: precipitation cells constitute a spatially interacting system; CPs come in generations; and scales steadily increase throughout the diurnal cycle. Finally, this model provides a framework for how CPs act to cause convective self‐organization, clustering, and extremes

Extracranial guiding structures for navigation to specific topographical sectors of the equine neopallium: an anatomical investigation performing three-dimensional distance measurements in adult warm-blooded horses

This basically anatomical study focuses on two items; firstly, the establishment of a system for the cartographic subdivision of the neopallium; secondly, the topographical correlation of extracranial landmarks and intracranial sites on the neopallium. The surface of the neopallium was subdivided into 15 Sectors with reference to a newly introduced pattern of Primary Sulci. The topographical link between extracranial landmarks and certain intracranial sites (i.e., neopallium Sectors) was elaborated by using a simple stereotactic device and a computer-assisted measurement device. Measurements were performed between points on the head´s outer surface and on the isolated brain. The introduction of an anatomical three-dimensional Coordinate System was an essential key issue for this investigation. This setting facilitated the measurements and calculations of the so-called Indirect Distances that were characterized by their alignment along the three orthogonal axes (x, y, z) of the anatomical Coordinate System. The inter-individual comparison (16 adult horses [Equus caballus]) of the Indirect Distances revealed that each Sector Center lay within a distinct morphometric Residence Area. The measured and calculated data also showed that each Sector Center could be assigned to its proper extracranial landmark that – in comparison with other landmarks – was best suited for the optimal allocation of the Sector Center Point

Active caspase-3 is removed from cells by release of caspase-3-enriched vesicles

AbstractCleavage of Rho associated Coiled Coil kinase I (ROCK I) by caspase-3 contributes to membrane blebbing. Whether caspase-3 and ROCK I also play a role in the release of membrane vesicles is unknown. Therefore, we transfected a human breast cancer cell line (MCF-7) that is caspase-3 deficient, lacks membrane blebbing, and does not release membrane vesicles, with caspase-3. Cells expressing caspase-3 demonstrate both ROCK I-mediated membrane blebbing, and release of small (400–600nm) membrane vesicles in a ROCK I-independent manner. These membrane vesicles contain caspase-3, and are enriched in caspase-3 activity compared to the releasing cells. Caspase-3-containing vesicles are taken up by untransfected cells but the cells do not show any sign of apoptosis. In conclusion, we show that the release of caspase-3-enriched membrane vesicles and membrane blebbing are two differentially regulated processes. Furthermore, we hypothesize that packaging of caspase-3 into membrane vesicles contributes to cellular homeostasis by the removal of caspase-3, and concurrently, protects the cells' environment from direct exposure to caspase-3 activity

Just-in-Time Encoding Into Visual Working Memory Is Contingent Upon Constant Availability of External Information

Humans maintain an intricate balance between storing information in visual working memory (VWM) and just-in-time sampling of the external world, rooted in a trade-off between the cost of maintaining items in VWM versus retrieving information as it is needed. Previous studies have consistently shown that one prerequisite of just-in-time sampling is a high degree of availability of external information, and that introducing a delay before being able to access information led participants to rely less on the external world and more on VWM. However, these studies manipulated availability in such a manner that the cost of sampling was stable and predictable. It is yet unclear whether participants become less reliant on external information when it is more difficult to factor in the cost of sampling that information. In two experiments, participants copied an example layout from the left to the right side of the screen. In Experiment 1, intermittent occlusion of the example layout led participants to attempt to encode more items per inspection than when the layout was constantly available, but this did not consistently result in more correct placements. However, these findings could potentially be explained by inherent differences in how long the example layout could be viewed. Therefore in Experiment 2, the example layout only became available after a gaze-contingent delay, which could be constant or variable. Here, the introduction of any delay led to increased VWM load compared to no delay, although the degree of variability in the delay did not alter behaviour. These results reaffirm that the nature of when we engage VWM is dynamical, and suggest that any disruption to the continuous availability of external information is the main driver of increased VWM usage relative to whether availability is predictable or not

Eye Movements as Proxy for Visual Working Memory Usage: Increased Reliance on the External World in Korsakoff Syndrome

In the assessment of visual working memory, estimating the maximum capacity is currently the gold standard. However, traditional tasks disregard that information generally remains available in the external world. Only when to-be-used information is not readily accessible, memory is taxed. Otherwise, people sample information from the environment as a form of cognitive offloading. To investigate how memory deficits impact the trade-off between sampling externally or storing internally, we compared gaze behaviour of individuals with Korsakoff amnesia (n = 24, age range 47–74 years) and healthy controls (n = 27, age range 40–81 years) on a copy task that provoked different strategies by having information freely accessible (facilitating sampling) or introducing a gaze-contingent waiting time (provoking storing). Indeed, patients sampled more often and longer, compared to controls. When sampling became time-consuming, controls reduced sampling and memorised more. Patients also showed reduced and longer sampling in this condition, suggesting an attempt at memorisation. Importantly, however, patients sampled disproportionately more often than controls, whilst accuracy dropped. This finding suggests that amnesia patients sample frequently and do not fully compensate for increased sampling costs by memorising more at once. In other words, Korsakoff amnesia resulted in a heavy reliance on the world as ‘external memory’

Eye Movements as Proxy for Visual Working Memory Usage: Increased Reliance on the External World in Korsakoff Syndrome

In the assessment of visual working memory, estimating the maximum capacity is currently the gold standard. However, traditional tasks disregard that information generally remains available in the external world. Only when to-be-used information is not readily accessible, memory is taxed. Otherwise, people sample information from the environment as a form of cognitive offloading. To investigate how memory deficits impact the trade-off between sampling externally or storing internally, we compared gaze behaviour of individuals with Korsakoff amnesia (n = 24, age range 47–74 years) and healthy controls (n = 27, age range 40–81 years) on a copy task that provoked different strategies by having information freely accessible (facilitating sampling) or introducing a gaze-contingent waiting time (provoking storing). Indeed, patients sampled more often and longer, compared to controls. When sampling became time-consuming, controls reduced sampling and memorised more. Patients also showed reduced and longer sampling in this condition, suggesting an attempt at memorisation. Importantly, however, patients sampled disproportionately more often than controls, whilst accuracy dropped. This finding suggests that amnesia patients sample frequently and do not fully compensate for increased sampling costs by memorising more at once. In other words, Korsakoff amnesia resulted in a heavy reliance on the world as ‘external memory’