A parsimonious laboratory system for the evaluation of rat reaching task: recovery from the massive destruction of motor areas

Previously, the design of sewer systems has been limited to studies of their hydraulic characteristics, in particular the ability of the system to convey the maximum discharge. Greater environmental awareness has necessitated that new designs, and some existing schemes, are assessed to determine the environmental load which the scheme will deliver to any downstream component. This paper describes a laboratory programme which has been designed to elucidate the effects of manholes on the longitudinal dispersion of solutes. A laboratory system is described, which allows in situ measurements to be taken of the concentration of a fluorescent solute tracer, both up- and down-stream of a surcharged manhole junction. Results are presented from a preliminary series of studies undertaken for a single manhole geometry over a range of discharges, with varying levels of surcharge. Results are presented showing the variation of travel time, change in second moment of the distribution and of a dispersion factor with surcharge, assuming a Taylor approach and determining the dispersion factor using a ‘change in moment’ method. The effect of the stored volume within the manhole is clearly evident. The limitations and the applicability of this approach are discussed.

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“Real-time” obstacle avoidance in the absence of primary visual cortex

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.0905549106 ◽

2009 ◽

Vol 106 (37) ◽

pp. 15996-16001 ◽

Cited By ~ 27

Author(s):

Christopher L. Striemer ◽

Craig S. Chapman ◽

Melvyn A. Goodale

Keyword(s):

Visual Cortex ◽

Real Time ◽

Obstacle Avoidance ◽

Primary Visual Cortex ◽

Posterior Parietal Cortex ◽

Dorsal Stream ◽

Visual Pathways ◽

Visual Stream ◽

Reaching Task ◽

Visual Inputs

When we reach toward objects, we easily avoid potential obstacles located in the workspace. Previous studies suggest that obstacle avoidance relies on mechanisms in the dorsal visual stream in the posterior parietal cortex. One fundamental question that remains unanswered is where the visual inputs to these dorsal-stream mechanisms are coming from. Here, we provide compelling evidence that these mechanisms can operate in “real-time” without direct input from primary visual cortex (V1). In our first experiment, we used a reaching task to demonstrate that an individual with a dense left visual field hemianopia after damage to V1 remained strikingly sensitive to the position of unseen static obstacles placed in his blind field. Importantly, in a second experiment, we showed that his sensitivity to the same obstacles in his blind field was abolished when a short 2-s delay (without vision) was introduced before reach onset. These findings have far-reaching implications, not only for our understanding of the time constraints under which different visual pathways operate, but also in relation to how these seemingly “primitive” subcortical visual pathways can control complex everyday behavior without recourse to conscious vision.

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Thymoma in an aged backyard Leghorn chicken, with reviews of a database and literature

Journal of Veterinary Diagnostic Investigation ◽

10.1177/1040638721990896 ◽

2021 ◽

Vol 33 (2) ◽

pp. 336-339

Author(s):

Julia Blakey ◽

Carmen Jerry ◽

Ana da Silva ◽

Simone Stoute

Keyword(s):

Soft Tissue Mass ◽

Animal Health ◽

Postmortem Examination ◽

Cervical Region ◽

Laboratory System ◽

Unexpected Death ◽

Tissue Mass ◽

Microscopic Features ◽

History Of ◽

Backyard Chickens

A 7-y-old backyard Leghorn chicken ( Gallus domesticus) was submitted to the California Animal Health and Food Safety Laboratory System (CAHFS)–Turlock branch for postmortem examination, with a history of unexpected death. At postmortem examination, a hemorrhagic soft tissue mass was observed in the cervical region. Microscopically, a densely cellular neoplasm of polygonal epithelial cells and small lymphocytes was observed. The microscopic features of the neoplasm in combination with positive immunohistochemistry for pancytokeratin and CD3 were used to classify the lesion as a thymoma. Thymoma was diagnosed in only 5 birds submitted to CAHFS from 1990 to 2019. Thymoma has been described only rarely in birds, and is an unusual diagnosis in backyard chickens.

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