Potential, Implications and Solutions Regarding the Use of Rendered Animal Fats in Aquafeeds

Problem statement: In the past, aquafeeds were comprised largely of fish meal and fish oil derived from marine reduction fisheries. In addition to being highly palatable and readily digested by cultured fishes, these feedstuffs were historically inexpensive sources of protein, energy and essential nutrients. However, increasing cost and concerns over safety and sustainability have greatly incentivized the transition from fish meal and oil to alternative sources of protein and lipid for aquafeed formulation. Fish oil replacement is proving more difficult than originally anticipated, particularly for marine carnivorous species. Approach: If complete fish oil replacement is not a viable goal for fish nutritionists and aquafeed manufacturers, at a minimum, we must strive for judicious use of limited marine-derived resources. In the present review, we explore the opportunities of using rendered fats as alternatives to marine-derived fish oils in aquaculture feeds, beginning with a discussion of the products themselves before reviewing the most recent literature and concluding with a discussion of the future of these products in aquafeed formulations. Results: Rendered fats have not been as intensively evaluated in aquaculture nutrition as grain and oilseed-derived lipids, although a number of recent publications on the subject suggest increasing interest in the use of rendered products in aquafeeds. Conclusion: Poultry fat, beef tallow, pork lard and to a lesser extent, yellow/restaurant grease and catfish oil, have been investigated individually or in combination with other lipids in feeds for a broad range of cultured taxa with generally acceptable results

Investigating Dimensions of Trust in Public Discussions of Diabetes Led by Certified Diabetes Educators

The givens of “trust” and “credibility” are often glossed over in research concerning the efficacy of community-based approaches to health issues. This research focuses on one type of community intervention aimed at increasing citizens’ interest in acting to address diabetes: a series of community discussions led by Certified Diabetes Educators (CDEs). We take a critical discourse analysis approach to answering several questions including: How does the discourse between CDEs and participants work to establish or hinder the CDEs’ credibility

Performance of winter pasture species in different integrated crop-livestock systems in lowlands of Southern Brazil.

The introduction of winter forage species in succession to rice cropping in lowlands of Southern Brazil is an option for the productive system diversification..

Animal production in different integrated crop-livestock systems in a lowland of Southern Brazil.

To achieve higher lowland use efficiency in Brazilian Southern, a region commonly used for rice production, the livestock activity during the winter period (in succession to summer crops) is a sustainable alternative..

Implementation of different integrated crop-livestock systems in lowlands of Southern Brazil: an animal production approach.

The introduction of integrated crop-livestock systems (ICLS) is an alternative to rice monoculture in lowlands of Southern Brazil..

Effects of V1 surround modulation tuning on visual saliency and the tilt illusion

Neurons in the primary visual cortex respond to oriented stimuli placed in the center of their receptive field, yet their response is modulated by stimuli outside the receptive field (the surround). Classically, this surround modulation is assumed to be strongest if the orientation of the surround stimulus aligns with the neuron's preferred orientation - irrespective of the actual center stimulus. This neuron-dependent surround modulation has been used to explain a wide range of psychophysical phenomena, such as biased tilt perception and saliency of stimuli with contrasting orientation. However, several neurophysiological studies have shown that for most neurons surround modulation is instead center-dependent: it is strongest if the surround orientation aligns with the center stimulus. As the impact of such center-dependent modulation on the population level is unknown, we examine this using computational models. We find that with neuron-dependent modulation the biases in orientation coding, commonly used to explain the tilt illusion, are larger than psychophysically reported, but disappear with center-dependent modulation. Therefore we suggest that a mixture of the two modulation types is necessary to quantitatively explain the psychophysically observed biases. Next, we find that under center-dependent modulation average population responses are more sensitive to orientation differences between stimuli, which in theory could improve saliency detection. However, this effect depends on the specific saliency model. Overall, our results thus show that center-dependent modulation reduces coding bias, while possibly increasing the sensitivity to salient features

Feedforward Inhibition and Synaptic Scaling – Two Sides of the Same Coin?

Feedforward inhibition and synaptic scaling are important adaptive processes that control the total input a neuron can receive from its afferents. While often studied in isolation, the two have been reported to co-occur in various brain regions. The functional implications of their interactions remain unclear, however. Based on a probabilistic modeling approach, we show here that fast feedforward inhibition and synaptic scaling interact synergistically during unsupervised learning. In technical terms, we model the input to a neural circuit using a normalized mixture model with Poisson noise. We demonstrate analytically and numerically that, in the presence of lateral inhibition introducing competition between different neurons, Hebbian plasticity and synaptic scaling approximate the optimal maximum likelihood solutions for this model. Our results suggest that, beyond its conventional use as a mechanism to remove undesired pattern variations, input normalization can make typical neural interaction and learning rules optimal on the stimulus subspace defined through feedforward inhibition. Furthermore, learning within this subspace is more efficient in practice, as it helps avoid locally optimal solutions. Our results suggest a close connection between feedforward inhibition and synaptic scaling which may have important functional implications for general cortical processing