Performance of lactating dairy cows fed varying levels of total mixed ration and pasture

Two, 8-week experiments, each using 30 lactating Holstein cows, were conducted to examine performance of animals offered combinations of total mixed ration (TMR) and high-quality pasture. Experiment 1 was initiated in mid October 2004 and Experiment 2 was initiated in late March 2005. Cows were assigned to either a 100% TMR diet (100:00, no access to pasture) or one of the following three formulated partial mixed rations (PMR) targeted at (1) 85% TMR and 15% pasture, (2) 70% TMR and 30% pasture and (3) 55% TMR and 45% pasture. Based on actual TMR and pasture intake, the dietary TMR and pasture proportions of the three PMR in Experiment 1 were 79% TMR and 21% pasture (79:21), 68% TMR and 32% pasture (68:32), and 59% TMR and 41% pasture (59:41), respectively. Corresponding proportions in Experiment 2 were 89% TMR and 11% pasture (89:11), 79% TMR and 21% pasture (79:21) and 65% TMR and 35% pasture (65:35), respectively. Reducing the proportion of TMR in the diets increased pasture consumption of cows on all PMR, but reduced total dry matter intake compared with cows on 100:00. An increase in forage from pasture increased the concentration of conjugated linoleic acids and decreased the concentration of saturated fatty acids in milk. Although milk and milk protein yields from cows grazing spring pastures (Experiment 2) increased with increasing intakes of TMR, a partial mixed ration that was composed of 41% pasture grazed in the fall (Experiment 1) resulted in a similar overall lactation performance with increased feed efficiency compared to an all-TMR ration.     

OPTIMIZATION OF THE OSMOTIC DEHYDRATION OF MANGO (MANGIFERA INDICA L.) SLICES

Fresh mango (Mangifera indica) slices were osmotically dehydrated using four treatment variables: treatment time, temperature, sugar concentration and slice thickness. Treatment times for 2, 4 and 6 mm slice thickness were 3, 5 and 7 h at temperatures of 20, 30 and 40°C and sugar concentrations of 40, 50 and 60% (w/w). The responses variables tested were weight reduction (WR), sugar gain (SG), final moisture content (M_f) and overall product acceptability (OA). A fractional factorial design (3 level-4 parameter) with 27 runs was used as the experimental design.

A Response Surface Methodology (RSM) was performed to analyze and predict the optimum conditions of the mango osmotic dehydration process. All treatment variables significantly affected WR, while SG and M_f were significantly affected only by thickness. On the other hand, none of the variables showed no significant effect on the OA.

The optimum conditions were determined with the following response limiting values: at least 30% WR, at least 8% in SG, M_f of not exceeding 70% were based on previous studies and panel evaluation results. The optimum conditions generated were: treatment time of 6 h, temperature of 35°C, sugar concentration of 65% (w/w) for 5 mm slice thickness. Results of validation tests were fairly acceptable since the Coefficient of Variation (CV) of the responses were less than 15% except for sugar gain with a 26.5% CV.     

Relative Configuration of a δ-Lactone Isolated from Mandibular Gland Secretion of Calomyrmex sp. Males

The relative configuration of a -lactone isolated from the mandibular gland extracts of Calomyrmex sp. males has been determined to be (3SR,5RS,6SR)-3,5,6-trimethyltetrahydropyran-2H-one after the synthesis of the four possible racemates and comparison of their mass spectra and gas chromatographic properties with those reported in the literature for the natural product.     

A Greedy Algorithm for Decomposing Convex Structuring Elements

This paper presents a greedy algorithm for decomposing convex structuring elements as sequence of Minkowski additions of subsets of the elementary square (i.e., the 3 × 3 square centered at the origin). The technique proposed is very simple and it is based on algebraic and geometric properties of Minkowski additions. Besides its simplicity, the advantage of this new technique over other known algorithms is that it generates a minimal sequence of not necessarily convex subsets of the elementary square. Thus, subsets with smaller cardinality are generated and a faster implementation of the corresponding dilations and erosions can be achieved. Experimental results, proof of correctness and analysis of computational time complexity of the algorithm are also given.     

Spatial bioaccumulation modeling in a network of bayous

A software system, Spatial Network Bioaccumulation Model (SNBM), was developed to model the bioaccumulation of polycyclic aromatic hydrocarbons (PAHs) in aquatic food webs. The SNBM uses a geographic information system as an engine to: (i) store the spatial representation of input parameters (the data related to the ecosystem), (ii) transfer input and output data to and from the food-web bioaccumulation model, and (iii) display the predicted food-web organism concentrations over a base map of the field site. The bioaccumulation model is a time-dependent, set of first-order ordinary differential equations that are solved numerically. Many sampling locations can be analyzed using the SNBM in one individual run. We demonstrate the system for a steady-state simulation of three PAHs, naphthalene, phenanthrene and benzanthracene in a food web for spotted gar (Lepisosteus oculatus) from the LaBranche Wetlands, Louisiana, USA. The predicted food-web organism concentrations are plotted at their respective sampling location.     

Thermoluminescence kinetic parameters of Bi4Ge3O12 single crystals

In this work, we present a detailed kinetic study of the thermoluminescence of Bi₄Ge₃O₁₂ (BGO) single crystals grown by the Czochralski technique. A single crystalline phase was confirmed through X-ray diffraction pattern analysis based on the Rietveld profile refinement method. The thermoluminescent (TL) glow curves were induced by UV or beta radiation and measured between 20 °C and 200 °C. The glow curves of BGO crystal presented two peaks at 61 °C and 90 °C for both kinds of radiation. The kinetic parameters, kinetic order (b), activation energy (E) and frequency factor (s), of the TL glow curves have been determined by four different methods. The lifetime of the peaks at room temperature was also determined and used to discuss the stability of the TL peaks at room temperature.     

Enzyme hydrolysis of babassu oil in a membrane bioreactor

This work deals with the enzymatic hydrolysis of babassu oil by immobilized lipase in a membrane bioreactor using unmixed aqueous and lipid streams. The experimental work was carried out in a flat plate membrane module with two different membranes: hydrophobic (nylon) and hydrophilic [mixed cellulose esters (MCE)], with different nominal pore sizes ranging from 0.10 to 0.65 μm. Candida cylindracea lipase was adsorbed on the membrane surface area, and the reactor was operated in batch mode. The initial enzymatic rate increased from 80 to 150 μmol H⁺/min when the organic phase velocity increased from 1.0×10⁻³ to 3.0×10⁻³ m/s, indicating that mass transfer in that phase was the process-limiting step. Calcium ions had a marked effect on immobilized lipase activity, increasing around twofold the lipolytic activity. Long-term experimental runs showed that the immobilized lipase remained stable for at least 8 d. The values for immobilized protein and maximal productivities observed for 0.45 μm membranes were: 1.01 g/m² and 193 μmol H⁺/m²·s for MCE membrane and 0.78 g/m² and 220 μmol H⁺/m²·s for nylon membrane. The productivities obtained are among the highest values reported in the technical literature.     

Hexyl Decanoate, the First Trail Pheromone Compound Identified in a Stingless Bee, Trigona recursa

Foragers of many species of stingless bees guide their nestmates to food sources by means of scent trails deposited on solid substrates between the food and the nest. The corresponding trail pheromones are generally believed to be produced in the mandibular glands, although definitive experimental proof has never been provided. We tested the trail following behavior of recruits of Trigona recursa in field experiments with artificial scent trails branching off from natural scent trails of this stingless bee. First-time recruits (newcomers) did not follow these trails when they were laid with pure solvent or mandibular gland extract. However, they did follow trails made with labial gland extract. Chemical analyses of labial gland secretions revealed that hexyl decanoate was the dominant component (72.4 ± 1.9% of all volatiles). Newcomers were significantly attracted to artificial trails made with synthetic hexyl decanoate, demonstrating its key function in eliciting scent-following behavior. According to our experiments with T. recursa, the trail pheromone is produced in the labial glands and not in the mandibular glands. Hexyl decanoate is the first component of a trail pheromone identified and proved to be behaviorally active in stingless bees.     

Influence of CAD-CAM milling on the flexural strength of Y-TZP dental ceramics

In this work, the influence of milling strategy and cutter wear on the flexural strength of sintered Y-TZP ceramics machined in a CAD-CAM system, was investigated. Pre-sintered Y-TZP blocks were machined with tungsten carbide (WC) milling cutters and divided into three groups: a) samples machined with New Cutting Tools (NCT); b) samples machined with End-of-life cutting tools (ELCT); and c) samples machined and subsequently polished. The samples were machined parallel and perpendicularly to the diameter of pre-sintered Y-TZP blocks aiming to evaluate the effect of the machining orientation on roughness. After cutting, the specimens were sintered at 1530?°C for 2?h and characterized. After sintering, dense Y-TZP samples presenting grain size average of 0.81?±?0.23?μm, hardness of 1205?±?12 HV, K_C of 7.7?±?0.4 MPam^1/2 and flexural strength of 1207?±?199?MPa were obtained. Furthermore, the control roughness (polished surfaces) presented R_a?=?0.058?±?0.011?μm. The surface roughness of the samples was influenced by the machining methodology using NCT mills, with R_a?=?0.386?±?0.149?μm and R_a?=?0.292?±?0.105?μm for samples machined parallel and perpendicularly to the pre-sintered Y-TZP blocks, respectively. The use of ELCT led to a roughness increasing (R_a?=?0.582?±?0.183?μm for samples milled perpendicularly, and R_a?=?0.919?±?0.164?μm for samples cut parallel to the pre-sintered blocks. The flexural strength of the sintered Y-TZP decreases with use of ELCT as consequence of surface roughness increasing, resulting from wear of WC mills, which presented chippings with sizes ranging from 30 to 340?μm in the cutting edge.     

Chemical modifications of lignocellulosic materials and their application for removal of cations and anions from aqueous solutions

This review discussed the last 10 years progress in the use of lignocellulosic materials chemically modified as low‐cost biosorbents. Thus, the chemical modifications, such as chemical pretreatment, oxidation, as well as the grafting of carboxyl groups, amines, amides, etc., on lignocellulosic fibers, that aim to increase the number of adsorption sites and maximize toxic metal ion adsorption capacity have been addressed. The literature presents results that indicated performances of biosorbents equal to or even higher than conventional methods and adsorbents. Many efforts have been concentrated on the improvements of these biosorbents through chemical modifications. However, some difficulties still exist, including the discharge of colored organic compounds resulting from the pretreatments and the development of fast, clean, and low‐cost synthesis of selective and multifunctional adsorbents. Thus, the challenge for future research is to find solutions to these difficulties in order to finally make lignocellulosics biosorbents that can replace conventional adsorbent materials. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43286.