Multivariate dynamic linear models for estimating the effect of experimental interventions in an evolutionary operations setup in dairy herds

Evolutionary operations is a method to exploit the association of often small changes in process variables, planned during systematic experimentation and occurring during the normal production flow, to production characteristics to find a way to alter the production process to be more efficient. The objective of this study was to construct a tool to assess the intervention effect on milk production in an evolutionary operations setup. The method used for this purpose was a dynamic linear model (DLM) with Kalman filtering. The DLM consisted of parameters describing milk yield in a herd, individual cows from a herd, and an intervention effect on a given day. The model was constructed to handle any number of cows, experimental interventions, different data sources, or presence of control groups. In this study, data from 2 commercial Danish herds were used. In herd 1, data on 98,046 and 12,133 milkings registered from an automatic milking system (AMS) were used for model building and testing, respectively. In herd 2, data on 3,689 milkings on test days were used for estimating the initial model parameters. For model testing, data from both bulk tank milk yield (85 observations) and test-day milkings (1,471) were used. In herd 1, the manager wanted to explore the possibility of reducing the amount of concentrate provided to the cows in an AMS. In herd 2, the manager wanted to know if the milk yield could be increased by elevating the energy level provided to the cows in a total mixed ration. The experiment conducted in herd 1 was designed with a treatment and a control group, whereas in herd 2 we used a pretest/posttest design. The constructed tool provided estimates (mean and confidence intervals) for each of 3 interventions carried out in both herds. In herd 1, we concluded that the reduction in concentrate amount provided in the AMS had no negative influence on milk yield. For herd 2, the increased level of energy had a significant positive effect on milk yield but only for the first intervention. In this herd, the effect of intervention was also evaluated for cows in the first lactation and without bulk tank records. The presented model proved to be a flexible and dynamic tool, and it was successfully applied for systematic experimentation in dairy herds. The model can serve as a decision support tool for on-farm process optimization exploiting planned changes in process variables and the response of production characteristics.     

Packaging materials with tailor made light transmission properties for food protection

Packaging material with optimal light barrier properties can prevent food quality deterioration. For dairy products, wavelength in the visible region between 400–450 nm and 600–650 nm should be blocked out due to the content of chlorophyll in dairy products. Six low density polyethylene blown films were formulated with the combination of four different pigments and additives: green, yellow, silver additive, and optical brightener, in addition to four reference samples. All films were transparent. Optical properties and light transmission were measured for each film, and microscopy analyses were used to investigate the surface topography. The sample containing high concentration of both green and yellow pigments had the lowest value in gloss and transmittance. This film blocked the light below 450 nm and transmitted 10% at 600–650 nm. Optical brightener had an effect only on visual appearance but not on light transmission properties. Samples containing silver additive were more intense green and gave a higher light transmission in blue region (380–500 nm) and lower in red region (600–700 nm) compared with samples without silver additive. These developed films can be applied in dairy products and other food products in the future. POLYM. ENG. SCI., 52:2015–2024, 2012. © 2012 Society of Plastics Engineers     

Conductivity enhancement in carbon nanocone adhesive by electric field induced formation of aligned assemblies

We show how an alternating electric field can be used to assemble carbon nanocones (CNCs) and align these assemblies into microscopic wires in a commercial two-component adhesive. The wires form continuous pathways that may electrically connect the alignment electrodes, which leads to directional conductivity (～10(-3) S/m) on a macroscopic scale. This procedure leads to conductivity enhancement of at least 2-3 orders of magnitude in the case where the CNC fraction (～0.2 vol %) is 1 order of magnitude below the percolation threshold (～2 vol %). The alignment and conductivity are maintained on curing that joins the alignment electrodes permanently together. If the aligned CNC wires are damaged before curing, they can be realigned by an extended alignment period. This concept has implications in areas such as electronic packaging technology.     

Emergent membrane-affecting properties of BSA-gold nanoparticle constructs

By adsorbing bovine serum albumin (BSA) on gold nanoparticles (Aunps) with diameters 30 nm and 80 nm, different degrees of protein unfolding were obtained. Adsorption and adlayer conformation were characterized by UV-vis spectroscopy, ζ-potential measurements, steady-state and time-resolved fluorescence. The unfolding was also studied using 1-anilino-8-naphthalene sulfonate (ANS) as an extrinsic probe, showing that BSA unfolds more on 80 nm Aunp than on 30 nm Aunp. Langmuir monolayer studies using two distinct methods of introducing the BSA and BSA-Aunp constructs accompanied with Brewster Angle Microscopy (BAM) and Digital Video Microscope (DVM) imaging demonstrated that BSA-Aunp constructs induce film miscibility with L-α-phosphatidylethanolamine not seen for BSA or Aunp alone. The changes induced by partial unfolding clearly give better film-penetration ability, as well as disruption of liquid crystalline domains in the film, thereby inducing film miscibility. Gold or protein only does not possess the nanoscale film-affecting properties of the protein-gold constructs, and as such the surface-active and miscibility-affecting characteristics of the BSA-Aunp represent emergent qualities.     

“SPURT FRACTURE” IN CAPILLARY FLOW

The critical conditions under which flow curves in capillary flow abruptly change their slope to zero (spurt) and the influence of solvent additive and solvent power on this phenomenon have been investigated. Based on a forced high elastic state concept an expression for the so-called spurt phenomenon, i.e. fracture-induced slip at the wall in a capillary of a capillary rheometer, is deduced. It is found that the spurt fracture stress, τ^s _cr, and the spurt fracture shear rate, γ^s _cr, can be represented by the master curve log (τ ^s _crr ((p/M_c)PE(M_c/p))^2/3 against log (a_T γ^s _cr), where a_T is the WLF shift factor, M_c the molecular weight between entanglements and p the density.

Estimation of slip rates at the wall and measurements on slightly crosslinked high density polyethylene supports the assumption that spurt results from melt fracture at the capillary wall.

Only addition of the non-solvent calcium stearate (with high density polyethylene) results in flow behavior which significantly deviates from that found for samples containing good solvents. Gel permeation chromato-graphy indicates that if chain scission resulting in lower molecular weight takes place, it will be limited to thin layers near the capillary wall.

melt fracture in the capillary cannot be reached. The flow behavior is influenced by addition of the non-solvent calcium stearate. The slopes of the flow curves is changed at relatively low shear rates but the high molecular weight polymer DMDS 5140 never the less shows spurt behavior at the same stress as for the pure sample.

This behavior may tentatively be interpreted as being caused by the formation of a boundary layer of non-solvent at low shear rate the thickness of which depends on the polymer and flow field. At stresses corresponding to the critical conditions, fracture in the polymer takes place. The interface between the non-solvent layer and the polymer matrix must according to Han61 be expected to be unstable     

Pattern Noise in the Frequency ΔΣ Modulator

In this paper, we show that the first-order frequency delta–sigma modulator is equivalent to a traditional delta–sigma modulator with respect to pattern noise. We further propose two techniques for reducing the effect of pattern noise. The first technique is based on time-domain dithering which is implemented by adding white phase noise to the FM signal. The second technique is based on locating the narrow dynamic range that may be in this kind of modulators, in a pattern noise valley. This technique can utilize pattern noise to make the modulator provide significantly higher digital resolution than the white quantization noise model predicts. Finally, the theory is verified by measurements.     

Regulatory Power,Network Tools and Market Behaviour: Transforming Practices in Norwegian Urban Planning

Planning changes can be initiated formally through revisions of statutory rules; alternatively changes can arise informally through amendments to everyday planning activities. This article explains how local planning authorities in Norway introduce new planning practices relating to the management of land and planning procedures. The observed new practices have been introduced even though the formal hierarchical structure of the planning law has stayed unchanged. They are analysed as outcomes of the changing use of tools under the three models for co-ordinating behaviour: hierarchy understood as government, market and network. First, the existing planning system is analysed to explain the legal possibilities for changing planning practices informally. Two categories of practices are then discussed: the use of the detailed development plan as an implementation instrument, and the use of the regulatory power in framing interconnections and responsibilities towards stakeholders. The main conclusion is that regulatory tools have lost some strength in favour of tools under the network model, and that the observed changes in planning practices are mostly a result of mutual dependencies between these two models for co-ordinating behaviour.     

SENSITIVITY ANALYSIS AND OPTIMIZATION OF ELASTIC-PLASTIC STRUCTURES

Elastic-plastic analysis problems formulated as quadratic programming problems involve energy functional and equilibrium and yield constraints that depend on the design, material and loading. In this paper we consider the problem of determining the variation of structural response with respect to variations of these parameters. A general result for discrete structures is presented and implications for optimal design are discussed.     

Instant infusion pasteurisation of bovine milk. II. Effects on indigenous milk enzymes activity and whey protein denaturation

Direct heat treatment of two milk types, skimmed and nonstandardised full‐fat, was performed by instant steam infusion and compared with indirect heating. Infusion conditions were temperatures of 72–120°C combined with holding times of 100–700 ms, and indirect heat conditions were 72°C/15 s and 85°C/30 s. The activity of indigenous enzymes such as alkaline phosphatase, lactoperoxidase, xanthine oxidase and γ‐glutamyl transpeptidase was evaluated. Infusion temperature was the main determinant of inactivation. Whey protein denaturation represented by β‐lactoglobulin increased significantly with infusion temperature. The nonstandardised milk had a higher denaturation rate than skimmed milk. The effect of instant infusion on pH and milk fat globule size in relation to whey protein denaturation and association is discussed.     

Dietary Fish Oil Alters DNA Methylation of Genes Involved in Polyunsaturated Fatty Acid Biosynthesis in Muscle and Liver of Atlantic Salmon (Salmo salar)

Adequate dietary supply of eicosapentaenoic acid (20:5n-3) and docosahexaenoic acid (22:6n-3) is required to maintain health and growth of Atlantic salmon (Salmo salar). However, salmon can also convert α-linolenic acid (18:3n-3) into eicosapentaenoic acid (20:5n-3) and docosahexaenoic acid (22:6n-3) by sequential desaturation and elongation reactions, which can be modified by 20:5n-3 and 22:6n-3 intake. In mammals, dietary 20:5n-3 + 22:6n-3 intake can modify Fads2 expression (Δ6 desaturase) via altered DNA methylation of its promoter. Decreasing dietary fish oil (FO) has been shown to increase Δ5fad expression in salmon liver. However, it is not known whether this is associated with changes in the DNA methylation of genes involved in polyunsaturated fatty acid synthesis. To address this, we investigated whether changing the proportions of dietary FO and vegetable oil altered the DNA methylation of Δ6fad_b, Δ5fad, Elovl2, and Elovl5_b promoters in liver and muscle from Atlantic salmon and whether any changes were associated with mRNA expression. Higher dietary FO content increased the proportions of 20:5n-3 and 22:6n-3 and decreased Δ6fad_b mRNA expression in liver, but there was no effect on Δ5fad, Elovl2, and Elovl5_b expression. There were significant differences between liver and skeletal muscle in the methylation of individual CpG loci in all four genes studied. Methylation of individual Δ6fad_b CpG loci was negatively related to its expression and to proportions of 20:5n-3 and 22:6n-3 in the liver. These findings suggest variations in dietary FO can induce gene-, CpG locus-, and tissue-related changes in DNA methylation in salmon.