Situating Cognition: Knowledge and Power in Context

Although adult education as a field has shown interest in the work of Lave and others concerning situated cognition, the authors argue that adult education as a field has misappropriated some of the central concepts of situated cognition

Cognition and Practice: Adult Learning Situated in Everyday Activity

Theories and procedures used to teach adults to write often lack an understanding of the central constitutive dimensions of activity, tools, and culture in adult learning. A situated view of teaching writing is introduced

On-farm Food Safety: Food Handling Guide

Details of safe food handling habits related to health, hygiene, and handwashing for all farm workers.https://lib.dr.iastate.edu/extension_pubs/1019/thumbnail.jp

Fish responses to flow velocity and turbulence in relation to size, sex and parasite load

Riverine fish are subjected to heterogeneous flow velocities and turbulence and may use this to their advantage by selecting regions that balance energy expenditure for station holding while maximizing energy gain through feeding opportunities. This study investigated microhabitat selection by guppies Poecilia reticulata in terms of flow characteristics generated by hemisphere boulders in an open channel flume. Velocity and turbulence influenced the variation in swimming behaviour with respect to size, sex and parasite intensity. With increasing body length, fish swam further and more frequently between boulder regions. Larger guppies spent more time in the areas of high-velocity and low-turbulence regions beside the boulders, whereas smaller guppies frequented the low-velocity and high-turbulence regions directly behind the boulders. Male guppies selected the regions of low velocity, indicating possible reduced swimming ability owing to hydrodynamic drag imposed by their fins. With increasing Gyrodactylus turnbulli burden, fish spent more time in regions with moderate velocity and lowest turbulent kinetic energy which were the most spatially and temporally homogeneous in terms of velocity and turbulence. These findings highlight the importance of heterogeneous flow conditions in river channel design owing to the behavioural variability within a species in response to velocity and turbulence

Fish swimming kinematics in a turbulent wake: to spill or not to spill?

Due to the complex nature of fish-environment interactions, the effects of altered flow conditions on fish habitats and behaviour, particularly near obstructions, are not yet fully understood. Many hydro-engineering structures generate three-dimensional turbulent structures that differ in properties from naturally occurring ones, and are challenging to fish movement. Here, swimming stability and habitat usage of Nile tilapia (Oreochromis niloticus) were examined in the turbulent wake of a horizontally oriented cylinder (50 mm diameter, D) for a series of increasing cylinder Reynolds numbers (Red). Velocity statistics showed that the near wake downstream of the cylinder within a 2D distance had higher magnitudes of longitudinal, vertical and lateral velocity components as well as Reynolds stresses, turbulence intensity and turbulent kinetic energy than the remaining wake flow field. Flow accelerating over the cylinder top and underside generated two shear horizontal layers, where two coherent structures were formed due to the shear layer breakdown off the cylinder’s walls and alternating von Karman-type vortex shedding occurred in the wake of the cylinder. The eddy symmetry and vorticity off the cylinder’s edges was dependent on Red. The recorded total number of spills, defined as loss of balance, was inversely proportional to fish length and weight, and depended on proximity to the cylinder and the flume bed. Furthermore, the frequency of spills was closely linked to the orientation of vortices and magnitude of Reynolds stresses, suggesting that these parameters may govern the swimming stability of fishes. This information may be used to inform the design of fish-friendly obstacles including hydraulic structures and hydro turbines in riverine and estuarine systems

Prior learning assessment: Systematic review of academic literature

Many argue a college degree is more important than ever and required for many occupations. However, pursuing one requires time and money. Prior learning assessment (PLA) offers one solution to overcome such barriers by documenting outside learning through competency portfolios or assessment testing to receive academic credit. The purpose of this systematic literature review was to examine the academic literature related to PLA within the United States. The review searched 669 databases, across 72 disciplines/fields, and yielded 47 peer-reviewed journal articles, published in 14 journals, during the last decade. Findings included six major themes with implications for adult education theory and practice

Experimental investigation of physical leaky barrier design implications on juvenile rainbow trout ( Oncorhynchus mykiss ) movement

Rivers have been subject to the construction of numerous small-scale anthropogenic structures, causing alteration and fragmentation of habitats. Despite their impact on fish habitat selection, migration and swimming performance, more hydraulic structures are being added to riverine systems. These mainly have the purpose of harnessing renewable energy or mitigating the impact of flooding, as in the case of leaky barriers that are widely used for natural flood management. By providing a sustainable and cost-effective supplement to traditional hard engineering flood risk management methods, these channel-spanning wooden barriers are constructed using sustainable, local materials, intended to slow down surface water and groundwater flow, reduce flood peaks, and attenuate the flow reaching downstream communities. Despite their increasing popularity, little is known about the design implications on fish movement or hydrodynamics. Using scaled laboratory flume experiments we investigate how the physical design of four leaky barriers varying in porosity, length, provision of overhead cover, and color, impacts on fish movement and spatial usage, and the channel hydrodynamics. Our fish behavioral analysis reveals that juvenile rainbow trout (Oncorhynchus mykiss) movement reduces with barrier presence. Upstream passage increases with barrier color but not cover, for shorter rather than longer leaky barriers, and for a non-porous barrier compared to its porous counterpart. Barrier specific flow alterations appear to play a secondary role compared to barrier color. Our study showed that physical barrier design and leaky barrier presence alter fish movement, and therefore care needs to be taken during the design of such natural flood management structures

Drag Force Measurements of Vegetation Elements

Source: ICHE Conference Archive - https://mdi-de.baw.de/icheArchiv