scholarly journals Mice identify subgoal locations through an action-driven mapping process

2021 ◽  
Author(s):  
Philip Shamash ◽  
Tiago Branco

Mammals instinctively explore and form mental maps of their spatial environments. Models of cognitive mapping in neuroscience mostly depict map-learning as a process of random or biased diffusion. In practice, however, animals explore spaces using structured, purposeful, sensory-guided actions. Here we test the hypothesis that executing specific exploratory actions is a key strategy for building a cognitive map. Previous work has shown that in arenas with obstacles and a shelter, mice spontaneously learn efficient multi-step escape routes by memorizing allocentric subgoal locations. We thus used threat-evoked escape to probe the relationship between ethological exploratory behavior and allocentric spatial memory. Using closed-loop neural manipulations to interrupt running movements during exploration, we found that blocking runs targeting an obstacle edge abolished subgoal learning. In contrast, blocking other movements while sparing edge-directed runs had no effect on memorizing subgoals. Finally, spatial analyses suggest that the decision to use a subgoal during escape takes into account the mouse's starting position relative to the layout of the environment. We conclude that mice use an action-driven learning process to identify subgoals and that these subgoals are then integrated into a map-based planning process. We suggest a conceptual framework for spatial learning that is compatible with the successor representation from reinforcement learning and sensorimotor enactivism from cognitive science.

2019 ◽  
Vol 16 (1) ◽  
Author(s):  
Olayemi Bakre ◽  
Nirmala Dorasamy

Poor service delivery has always been considered a legacy of the apartheid era. However, 25 years into democracy, many local municipalities are still battling with service delivery backlogs. These backlogs are often attributed to, for example, dysfunctional ward committees, corruption amongst councillors, exclusion of community members in the planning process, failure to prioritise community needs, and institutional capacity issues. These challenges have undermined municipalities’ provision of quality service delivery and have precipitated service delivery protests. This article argues that community participation, which has been identified as a factor that can mitigate the aforementioned challenges, can be pivotal in the provision of effective and efficient services by municipalities. The relationship between community inclusion and service delivery outcomes is not simplistic, but depend upon a combination of proactive and highly skilled leaders and a cooperative and supportive populace. In this article, we identify the modes for successful participation and also the consequences of community exclusion through textual analysis of pertinent sources. We argue that such participation can only be successful and sustainable if it is reinforced by support from local government in the form of community training and capacity development workshops to exchange and instil new ideas as well as by resource allocation.


2007 ◽  
Author(s):  
Fábio Frezatti ◽  
Andson Braga Aguiar ◽  
Reinaldo Guerreiro ◽  
Maria Aparecida Gouvêa

2019 ◽  
Author(s):  
Justin Harris

Many theories of conditioning describe learning as a process by which stored information about the relationship between a conditioned stimulus (CS) and unconditioned stimulus (US) is progressively updated upon each occasion (trial) that the CS occurs with, or without, the US. These simple trial-based descriptions can provide a powerful and efficient means of extracting information about the correlation between two events, but they fail to explain how animals learn about the timing of events. This failure has motivated models of conditioning in which animals learn continuously, either by explicitly representing temporal intervals between events, or by sequentially updating an array of associations between temporally distributed elements of the CS and US. Here, I review evidence that some aspects of conditioning are not the consequence of a continuous learning process but reflect a trial-based process. In particular, the way that animals learn about the absence of a predicted US during extinction suggests that they encode and remember trials as single complete episodes rather than as a continuous experience of unfulfilled expectation of the US. These memories allow the animal to recognise repeated instances of non-reinforcement and encode these as a sequence which, in the case of a partial reinforcement schedule, can become associated with the US. The animal is thus able to remember details about the pattern of a CS’s reinforcement history, information that affects how long the animal continues to respond to the CS when all reinforcement ceases.


2018 ◽  
Vol 31 (5) ◽  
pp. 406-414 ◽  
Author(s):  
Mohammadkarim Bahadori ◽  
Ehsan Teymourzadeh ◽  
Hamidreza Tajik ◽  
Ramin Ravangard ◽  
Mehdi Raadabadi ◽  
...  

PurposeStrategic planning is the best tool for managers seeking an informed presence and participation in the market without surrendering to changes. Strategic planning enables managers to achieve their organizational goals and objectives. Hospital goals, such as improving service quality and increasing patient satisfaction cannot be achieved if agreed strategies are not implemented. The purpose of this paper is to investigate the factors affecting strategic plan implementation in one teaching hospital using interpretive structural modeling (ISM).Design/methodology/approachThe authors used a descriptive study involving experts and senior managers; 16 were selected as the study sample using a purposive sampling method. Data were collected using a questionnaire designed and prepared based on previous studies. Data were analyzed using ISM.FindingsFive main factors affected strategic plan implementation. Although all five variables and factors are top level, “senior manager awareness and participation in the strategic planning process” and “creating and maintaining team participation in the strategic planning process” had maximum drive power. “Organizational structure effects on the strategic planning process” and “Organizational culture effects on the strategic planning process” had maximum dependence power.Practical implicationsIdentifying factors affecting strategic plan implementation is a basis for healthcare quality improvement by analyzing the relationship among factors and overcoming the barriers.Originality/valueThe authors used ISM to analyze the relationship between factors affecting strategic plan implementation.


Scanning ◽  
2017 ◽  
Vol 2017 ◽  
pp. 1-8
Author(s):  
Chao Zhou ◽  
Lu Deng ◽  
Long Cheng ◽  
Zhiqiang Cao ◽  
Shuo Wang ◽  
...  

In the motion of probing nanostructures, repeating position and movement is frequently happing and tolerance for position error is stringent. The consistency between the axis of manipulators and image is very significant since the visual servo is the most important tool in the automated manipulation. This paper proposed an automated axis alignment method for a nanomanipulator inside the SEM by recognizing the position of a closed-loop controlling the end-effector, which can characterize the relationship of these two axes, and then the rotation matrix can be calculated accordingly. The error of this method and its transfer function are also calculated to compare the iteration method and average method. The method in this paper can accelerate the process of axis alignment to avoid the electron beam induced deposition effect on the end tips. Experiment demonstration shows that it can achieve a 0.1-degree precision in 90 seconds.


Author(s):  
Antonio Caperna

This chapter analyses the Information and Communication Technologies (hereafter referred to as ICT) phenomenon, the opportunities it offers, the potential problems, and the relationship with local policies. It moves on the actions needed to develop, within the Agenda 21 process, a framework able to define some fundamental features for a new spatial theory in the information age, which will eventually consider Information and Communication Technology not just a simple tool, but a crucial aspect of a sustainable policy, capable, if well addressed, to mitigate various current or emerging territorial challenges such as literacy and education, public participation in the planning process, social and geographical divide, institutional transparency, etc.. This chapter will illustrate a framework able to assist politicians and planners in planning a sustainable development through ICT.


Author(s):  
Pu Gao ◽  
Jiageng Ruan ◽  
Yongchang Du ◽  
Paul D Walker ◽  
Nong Zhang

Aiming at improving regenerative braking ability in electric vehicles without compromising any safety, two different regenerative braking strategies are proposed in this study. The impact of continuously varying braking force distributions between front/rear wheel and electric/friction corresponding in two different strategies on braking noise are investigated. Based on the closed-loop coupling disk brake model, the relationship between the contact coupling stiffness and the braking force is established by considering the stationary modal test, the nonlinear optimization, and the relationship between brake-line pressure and braking force. The continuously varying braking force is initially transformed to continuously varying contact coupling stiffness, then, the brake noise tendency at each frequency band is calculated in closed-loop coupled model. The predicted result shows good consistency with the result recorded in bench test, verifying the reliability and effectivity of the presented method. The comparison of the two different electric braking strategies shows that the second braking strategy is superior to the first braking strategy in terms of suppressing the brake noise tendency.


Machines ◽  
2020 ◽  
Vol 8 (3) ◽  
pp. 41
Author(s):  
Tatsuya Yamamoto ◽  
Nobuyuki Iwatsuki ◽  
Ikuma Ikeda

The systematic kinematic analysis method for planar link mechanisms based on their unique procedures can clearly show the analysis process. The analysis procedure is expressed by a combination of many kinds of conversion functions proposed as the minimum calculation units for analyzing a part of the mechanism. When it is desired to perform this systematic kinematics analysis for a specific linkage mechanism, expert researchers can accomplish the analysis by searching for the procedure by themselves, however, it is difficult for non-expert users to find the procedure. This paper proposes the automatic procedure extraction algorithm for the systematic kinematic analysis of closed-loop planar link mechanisms. By limiting the types of conversion functions to only geometric calculations that are related to the two-link chain, the analysis procedure can be represented by only one type transformation function, and the procedure extraction algorithm can be described as a algorithm searching computable 2-link chain. The configuration of mechanism is described as the “LJ-matrix”, which shows the relationship of connections between links with pairs. The algorithm consists of four sub-processes, namely, “LJ-matrix generator”, “Solver process”, “Add-link process”, and “Over-constraint resolver”. Inputting the sketch of the mechanism into the proposed algorithm, it automatically extracts unique analysis procedure and generate a kinematic analysis program as a MATLAB code based on it. Several mechanisms are analyzed as examples to show the usefulness of the proposed method.


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