Hay to reduce dietary cation-anion difference for dry dairy cows

Timothy grass has a lower dietary cation-anion difference [DCAD = (Na + K) - (Cl + S)] than other cool-season grass species. Growing timothy on low-K soils and fertilizing it with CaCl₂ could further decrease its DCAD. The objective of this study was to evaluate the effects of feeding low-DCAD timothy hay on dry dairy cows. Six nonpregnant and nonlactating cows were used in a replicated 3 × 3 Latin square. Treatments were as follows: 1) control diet (control; DCAD = 296 mEq/kg of dry matter); 2) low-DCAD diet based on low-DCAD timothy hay (L-HAY; DCAD = - 24 mEq/kg of dry matter); and 3) low-DCAD diet using HCl (L-HCl; DCAD = - 19 mEq/kg of dry matter). Decreasing DCAD with L-HAY had no effect on dry matter intake (11.8 kg/d) or dry matter digestibility (71.5%). Urine pH decreased from 8.21 to 5.89 when L-HAY was fed instead of the control. Blood parameters that decreased with L-HAY were base excess (− 0.4 vs. 3.8 mM) and HCO₃⁻ (23 vs. 27 mM), and blood parameters that increased were Ca²⁺ (5.3 vs. 5.1 mg/dL), Cl⁻ (30.5 vs. 29.5 mg/dL), and Na⁺ (60.8 vs. 60.1 mg/dL). Compared with the control, L-HAY resulted in more Ca in urine (13.4 vs. 1.2 g/d). Comparing L-HAY with L-HCl, cow dry matter intake tended to be higher (11.5 vs. 9.8 kg/d), and blood pH was higher (7.37 vs. 7.31). Urine pH; total dry matter; Ca, K, P, and Mg apparent absorption; and Ca, K, Na, Cl, S, P, and Mg apparent retention were similar. Absorption as a percentage of intake of Na and Cl was lower for L-HAY as compared with L-HCl. In an EDTA-challenge test, cows fed L-HAY regained their initial level of blood Ca²⁺ twice as quickly as the control treatment (339 vs. 708 min); there were no differences between L-HAY and L-HCl. This experiment confirms that feeding low-DCAD hay is an effective means of decreasing the DCAD of rations and obtaining a metabolic response in dry dairy cows.     

Development and Application of a Rheological Method to Investigate Crystallization of Palm Oil

Structuring of fatty products is important in producing palatable food products. Saturated fat (SAFA) crystals are needed to bring structure to many products (such as bakery or confectionery). In a product control of the structure by fat nucleation and crystallization, it is important to deliver the correct performance. Many techniques only work on quiescent systems and give limited information about the sheared systems that are generally found in industrial production of products. This article presents a novel rheological technique that can be used to probe crystallization and network structure under sheared conditions. The results show that crystallization of palm oil can be divided into different key stages. These result from initial nucleation, structuring by the crystals, polymorphic transformation, further structure building, and then subsequent relaxation. Significant postcrystallization (sintering) events occur over at least a day. It is seen that the shear rate leads to possibilities for crystallization control. Higher shear gives a reduction in network strength (as measured by G′) of the initial crystal network. However, after longer posthardening, results are very similar. This work enables the development of a fast tool that can be used to monitor structure formation in fats and reveals the relative importance of the nucleation–crystallization and postcrystallization events in sheared systems.     

Using 3D modeling and remote sensing capabilities for a better understanding of spatio-temporal heterogeneities of phytoplankton abundance in large lakes

Lake biological parameters show important spatio-temporal heterogeneities. This is why explaining the spatial patchiness of phytoplankton abundance has been a recurrent ecological issue and is an essential prerequisite for objectively assessing, protecting and restoring freshwater ecosystems. The drivers of these heterogeneities can be identified by modeling their dynamics. This approach is useful for theoretical and applied limnology. In this study, a 3D hydrodynamic model of Lake Geneva (France/Switzerland) was created. It is based on the Delft3D suite software and includes the main tributary (Rhône River) and two-dimensional high-resolution meteorological forcing. It provides 3D maps of water temperature and current velocities with a 1?h time step on a 1?km horizontal grid size and with a vertical resolution of 1?m near the surface to 7?m at the bottom of the lake. The dynamics and the drivers of phytoplankton heterogeneities were assessed by combining the outputs of the model and chlorophyll-a concentration (Chl-a) data from MERIS satellite images between 2008 and 2012. Results highlight physical mechanisms responsible for the occurrence of seasonal hot-spots in phytoplankton abundance in the lake. At the beginning of spring, Chl-a heterogeneities are usually caused by an earlier onset of phytoplankton growth in the shallowest and more sheltered areas; spatial differences in the timing of phytoplankton growth can be explained by spatial variability in thermal stratification dynamics. In summer, transient and locally higher phytoplankton abundances are observed in relation to the impact of basin-scale upwelling.     

Two Plane-Probing Algorithms for the Computation of the Normal Vector to a Digital Plane

Digital planes are sets of integer points located between two parallel planes. We present a new algorithm that computes the normal vector of a digital plane given only a predicate “is a point x in the digital plane or not”. In opposition to classical recognition algorithm, this algorithm decides on-the-fly which points to test in order to output at the end the exact surface characteristics of the plane. We present two variants: the H-algorithm, which is purely local, and the R-algorithm which probes further along rays coming out from the local neighborhood tested by the H-algorithm. Both algorithms are shown to output the correct normal to the digital planes if the starting point is a lower leaning point. The worst-case time complexity is in \(O(\omega )\) for the H-algorithm and \(O(\omega \log \omega )\) for the R-algorithm, where \(\omega \) is the arithmetic thickness of the digital plane. In practice, the H-algorithm often outputs a reduced basis of the digital plane while the R-algorithm always returns a reduced basis. Both variants perform much better than the theoretical bound, with an average behavior close to \(O(\log \omega )\). Finally, we show how this algorithm can be used to analyze the geometry of arbitrary digital surfaces, by computing normals and identifying convex, concave or saddle parts of the surface. This paper is an extension of Lachaud et al. (Proceedings of 19th IAPR international conference discrete geometry for computer imagery (DGCI’2016), Nantes, France. Springer, Cham, 2016).     

The hydrogen evolution reaction in an acid medium on nickel electrodeposited with SiW12O 40 4− or SiMo12O 40 4− from electrolytes of various anionic compositions

Nickel was electrodeposited from baths based mainly on dilute aqueous solutions of nickel chloride, sulphate or acetate containing SiW₁₂O ₄₀ ^4– or SiMo₁₂O ₄₀ ^4– anions. Each bath contained one of the ions. The other chemical constituents of the solutions were the same in all of the baths. It was shown that improvement in the overpotential () and in the exchange current density (i ₀) of the electrodes depends both on the composition of the deposition bath and on deposition time. The h.e.r. electrocatalytic activity of the electrodeposits was then analysed and related to their chemical composition. The results show that some extremely active electrocatalysts are produced when combinations of nickel-tungsten (Ni–W) or nickel-molybdenum (Ni–Mo) are formed. The discussion is extended to include typical hypo-hyper-d-electronic transition metals, and it is concluded that alloying these metals significantly increases electrocatalytic activity.     

Compartment tests of polyurethane foam seating assemblies

Data from compartment tests of polyurethane foam seating assemblies are reported. Results show that the behavior of such assemblies during fires is strongly dependent on the type and position of interliners and upholstery fabrics. An incidental comparison of peak rate of heat release obtained in a compartment test with a predictive model equation is made and selected data from the tests are presented.