Characterization of carinata tolerance to select herbicides using field dose-response studies

Field experiments were conducted from 2017 to 2019 to determine the tolerance of carinata to several preemergence and postemergence herbicides. Preliminary screenings identified herbicides which caused large variation on carinata injury, indicating the potential for selectivity. Dose-response field studies were conducted to quantify the tolerance of carinata to select herbicides. Diuron applied preemergence at rates of 280 g ai ha−1 or above reduced carinata population density 54% to 84% compared to the nontreated control. In certain locations, clomazone applied preemergence caused minor injury with an acceptable level of carinata tolerance and only doses above 105 g ai ha−1 caused yield reductions. Napropamide doses of 2,856 g ai ha−1 or higher applied preemergence caused at least 25% injury to carinata; however, the damage was not severe enough to reduce yields. Simazine applied postemergence at rates above 1,594 g ai ha−1 caused 50% or more injury, resulting in yield losses ranging from 0 to 95% depending on location. Clopyralid applied postemergence at 2,512 g ai ha−1 caused 25% injury with relative yield reductions which varied across locations. The present study identified clomazone and napropamide applied preemergence, and clopyralid applied postemergence as potential herbicides for weed control in carinata. In contrast, diuron, simazine, metribuzin, imazethapyr, and chlorimuron caused high levels of carinata mortality and can be used to control volunteer carinata plants in rotational crops.

Landmark-Centered Coding in Frontal Cortex Visual Responses

Visual landmarks influence spatial cognition, navigation and goal-directed behavior, but their influence on visual coding for action is poorly understood. Here, we tested landmark influence on prefrontal visual responses by recording from 568 neurons in the frontal (FEF) and supplementary (SEF) eye fields of rhesus macaques. The response field (the area of visual space that modulates activity) for each neuron was tested in the presence of a landmark placed at one of four configurations. We then fit the spatially tuned response fields against a spatial coordinate continuum between gaze- and landmark-centered models. When response fields were fit separately for each target-landmark configuration, the best fits shifted (mean 37% / 40%) toward landmark-centered coding in FEF / SEF respectively, confirming a configuration-dependent intermediate coding scheme. Overall, these data show that external landmarks influence prefrontal visual responses, possibly helping to stabilize movement goals in the presence of noisy internal egocentric signals.

Static response analysis of a dual crane system using fuzzy parameters

Static response analysis of a dual crane system (DCS) is conducted using fuzzy parameters. The fuzzy static equilibrium equation is established and two fuzzy perturbation methods, including the compound function/fuzzy perturbation method (CFFPM) and modified compound function/fuzzy perturbation method (MCFFPM), are presented. The CFFPM employs the level-cut technique to transform the fuzzy static equilibrium equation into several interval equations with different cut levels. The interval Jacobian matrix, the first and second interval virtual work vectors, and the inverse of interval Jacobian matrix are approximated by the first-order Taylor series and Neumann series. The fuzzy static response field for every cut level is obtained by a synthesis of the compound function technique, the interval perturbation method, and the fuzzy algorithm. In the MCFFPM, the fuzzy static response field for every cut level is derived based on the surface rail generation method, the modified Sherman–Morrison–Woodbury formula, and the fuzzy theory. Compared with the Monte Carlo method (MCM), numerical examples demonstrate that the MCFFPM has a better accuracy than the CFFPM and both of them bring a higher efficiency than the MCM, especially when it comes to uncertainty quantification of fuzzy parameters on the static response of the DCS.

DESIGN OF A COVID-19 RESPONSE FIELD HOSPITAL

This paper includes the methodology and avenues of approach involved in a comprehensive design of a Vapor Compression Cycle (VCC) for a Heating, Ventilating, and Air Conditioning (HVAC) system accommodating a mobile hospital. The development and deployment of this hospital is in response to the current global COVID-19 pandemic and its regional effect on existing local care facilities.

Spatial and temporal structure of choice representations in primate prefrontal cortex

Divergent accounts of how choices are represented by neural populations have led to conflicting explanations of the underlying mechanisms of decision-making, ranging from persistent, attractor-based dynamics to transient, sequence-based dynamics. To evaluate these mechanisms, we characterize the spatial and temporal structure of choice representations in large neural populations in prefrontal cortex. We find that the pronounced diversity of choice responses across neurons reflects only a few, mostly persistent population patterns recruited at progressively later times before and after a choice. Brief sequential activity occurs during a saccadic choice, but is entirely absent in a delay preceding it. The diversity of choice responses, which could result from almost-random connectivity in the underlying circuits, instead largely reflects the topographical arrangement of response-field properties across the cortical surface. This spatial organization appears to form a fixed scaffold upon which the context-dependent representations of task-specific variables often observed in prefrontal cortex can be learned.