ENVIRONMENTAL RISK MANAGEMENT IN THE HORTICULTURAL INDUSTRY

This paper uses environmental risk assessment as a nutrient management planning tool to determine the best set of actions to control nutrient nonpoint source pollution in the horticultural industry. The framework minimizes costs subject to obtaining an environmental risk management score at or below a threshold value.Crop Production/Industries, Environmental Economics and Policy,

Effect of Fermentation with Streptococcus thermophilus Strains on In Vitro Gastro-Intestinal Digestion of Whey Protein Concentrates

Three Streptococcus thermophilus strains, namely RBC6, RBC20, and RBN16, were proven to release bioactive peptides during whey protein concentrate (WPC) fermentation, resulting in WPC hydrolysates with biological activities. However, these bioactive peptides can break down during gastro-intestinal digestion (GID), hindering the health-promoting effect of fermented WPC hydrolysates in vivo. In this work, the effect of simulated GID on three WPC hydrolysates fermented with S. thermophilus strains, as well as on unfermented WPC was studied in terms of protein hydrolysis, biological activities, and peptidomics profiles, respectively. In general, WPC fermentation enhanced protein hydrolysis compared to unfermented WPC. After in vitro GID, WPC fermented with S. thermophilus RBC20 showed the highest antioxidant activity, whereas WPC fermented with strain RBC06 displayed the highest angiotensin-converting enzyme (ACE)- and dipeptidyl peptidase IV (DPP-IV)-inhibitory activities. Peptidomics analysis revealed that all digested WPC samples were highly similar to each other in peptide profiles, and 85% of the 46 identified bioactive peptides were shared among fermented and unfermented samples. However, semi-quantitative analysis linked the observed differences in biological activities among the samples to differences in the amount of bioactive peptides. The anti-hypertensive peptides VPP and IPP, as well as the DPP-IV-inhibitory peptide APFPE, were quantified. In conclusion, WPC fermentation with S. thermophilus positively impacted protein hydrolysis and bioactive peptide release during GID

Effect of Ripening and In Vitro Digestion on Bioactive Peptides Profile in Ras Cheese and Their Biological Activities

The effect of ripening and in vitro digestion on the biological activities, peptide profiles and release of bioactive peptides in Ras cheese has been investigated. Ras cheese ripening largely influenced the extent of protein hydrolysis. The advancement in ripening resulted in an increase in total peptides (from 0.97 to 2.46 mmol leucine/g in samples at 30 and 180 days of ripening, respectively) and bioactive peptides concentration, especially angiotensin-converting enzyme (ACE)-inhibitory, dipeptidyl-peptidase-IV-(DPP-IV)-inhibitory and antioxidant peptides. In vitro gastro-intestinal digestion further promoted protein hydrolysis and the release of bioactive peptides. Digested Ras cheese at 90 and 180 days of ripening displayed the highest bioactive peptides intensity. The variations in bioactive peptides amount during ripening and in vitro digestion were correlated with the changes in ACE-inhibitory, DPP-IV-inhibitory and antioxidant activities. The highest amounts of VPP and IPP were detected in digested Ras cheese at 90 days of ripening (17.44 and 36.50 mg/kg of cheese, respectively), whereas the highest concentrations of APFPE were found in undigested and digested 180-day ripened Ras cheese (82.09 and 52.01 mg/kg of cheese, respectively). The present investigation underlined potential differences in the biological effect after the ingestion of Ras cheese at different ripening times

Breakdown of Energy Equipartition in a 2D Binary Vibrated Granular Gas

We report experiments on the equipartition of kinetic energy between grains made of two different materials in a mixture of grains vibrated in 2 dimensions. In general, the two types of grains do not attain the same granular temperature, Tg = 1/2m v^2. However, the ratio of the two temperatures is constant in the bulk of the system and independent of the vibration velocity. The ratio depends strongly on the ratio of mass densities of the grains, but is not sensitive to the inelasticity of grains. Also, this ratio is insensitive to compositional variables of the mixture such as the number fraction of each component and the total number density. We conclude that a single granular temperature, as traditionally defined, does not characterize a multi-component mixture.Comment: 4 pages, 5 figures, submitted to Physical Review Letters, updated reference

Close-packed floating clusters: granular hydrodynamics beyond the freezing point?

Monodisperse granular flows often develop regions with hexagonal close packing of particles. We investigate this effect in a system of inelastic hard spheres driven from below by a "thermal" plate. Molecular dynamics simulations show, in a wide range of parameters, a close-packed cluster supported by a low-density region. Surprisingly, the steady-state density profile, including the close-packed cluster part, is well described by a variant of Navier-Stokes granular hydrodynamics (NSGH). We suggest a simple explanation for the success of NSGH beyond the freezing point.Comment: 4 pages, 5 figures. To appear in Phys. Rev. Let

Effects of dietary supplementation of soybean lecithin on growth performance, nutrients digestibility and serum profiles of broilers fed fried soybean oil

The objective of this study was to evaluate the effects of soybean lecithin in broiler diets formulated with either fried or non-fried soybean oils (as an energy source), on growth performance, digestibility, and some serum parameters. A total of 600 broilers (50% male) were assigned to 4 experimental groups (with 10 replicates of 15 birds each): (i) group (S) fed with soybean oil only, (ii) group (SL) fed with soybean oil + lecithin (0.035% in feed), (iii) group (F) fed with fried soybean oil only, and iv) group (FL) fed with fried soybean oil + lecithin (0.035% in feed). The results showed that fried soybean oil in broilers diets had the same effects on the analysed parameters as the non-fried oil. Broilers that received lecithin with fried soybean oil (group FL) exhibited significantly higher body weights (1.228 vs. 1.210, p<0.05 and 1.935 vs. 1.917 kg, p<0.05) than group F in the last two experimental periods (22-28 and 29-35 d), respectively. On the contrary, the addition of soybean lecithin to diets formulated with either fried or non-fried soybean oil resulted in a significant increase in weight of some carcass cuts (thigh, breast) and a significant decrease in some visceral organs (intestine, liver, viscera), without affecting the digestibility parameters here assessed. Our findings revealed that the addition of soybean lecithin to standard soybean oil (group SL) significantly decreased serum TG (77.16 vs. 83.46, p<0.05) compared to group S. In conclusion, it was possible to use recovered frying soybean oil in broiler diets without a negative impact on growth performance and serum triglyceride level, while these parameters were improved by the addition of soybean lecithin

Advances in surface EMG signal simulation with analytical and numerical descriptions of the volume conductor

Surface electromyographic (EMG) signal modeling is important for signal interpretation, testing of processing algorithms, detection system design, and didactic purposes. Various surface EMG signal models have been proposed in the literature. In this study we focus on 1) the proposal of a method for modeling surface EMG signals by either analytical or numerical descriptions of the volume conductor for space-invariant systems, and 2) the development of advanced models of the volume conductor by numerical approaches, accurately describing not only the volume conductor geometry, as mainly done in the past, but also the conductivity tensor of the muscle tissue. For volume conductors that are space-invariant in the direction of source propagation, the surface potentials generated by any source can be computed by one-dimensional convolutions, once the volume conductor transfer function is derived (analytically or numerically). Conversely, more complex volume conductors require a complete numerical approach. In a numerical approach, the conductivity tensor of the muscle tissue should be matched with the fiber orientation. In some cases (e.g., multi-pinnate muscles) accurate description of the conductivity tensor may be very complex. A method for relating the conductivity tensor of the muscle tissue, to be used in a numerical approach, to the curve describing the muscle fibers is presented and applied to representatively investigate a bi-pinnate muscle with rectilinear and curvilinear fibers. The study thus propose an approach for surface EMG signal simulation in space invariant systems as well as new models of the volume conductor using numerical methods

Climate Change Effects on Agriculture: Economic Responses to Biophysical Shocks

Agricultural production is sensitive to weather and thus directly affected by climate change. Plausible estimates of these climate change impacts require combined use of climate, crop, and economic models. Results from previous studies vary substantially due to differences in models, scenarios, and data. This paper is part of a collective effort to systematically integrate these three types of models. We focus on the economic component of the assessment, investigating how nine global economic models of agriculture represent endogenous responses to seven standardized climate change scenarios produced by two climate and five crop models. These responses include adjustments in yields, area, consumption, and international trade. We apply biophysical shocks derived from the Intergovernmental Panel on Climate Change's representative concentration pathway with end-of-century radiative forcing of 8.5 W/m(sup 2). The mean biophysical yield effect with no incremental CO2 fertilization is a 17% reduction globally by 2050 relative to a scenario with unchanging climate. Endogenous economic responses reduce yield loss to 11%, increase area of major crops by 11%, and reduce consumption by 3%. Agricultural production, cropland area, trade, and prices show the greatest degree of variability in response to climate change, and consumption the lowest. The sources of these differences include model structure and specification; in particular, model assumptions about ease of land use conversion, intensification, and trade. This study identifies where models disagree on the relative responses to climate shocks and highlights research activities needed to improve the representation of agricultural adaptation responses to climate change