Improving performance of finishing pigs with added valine,isoleucine, and tryptophan: validating a meta-analysis model

Based on results of a recent meta-analysis, we hypothesized that increased dietary Val, Ile, or Trp could correct possible amino acid interactions because of excess Leu in diets containing high levels of corn protein, namely dried distiller’s grains with solubles (DDGS). A total of 1,200 pigs (PIC TR4 × (Fast LW × PIC L02); initially 33.6 ± 0.6 kg) were used in a 103-d study. The 6 dietary treatments were corn–soybean meal (SBM)-DDGS-based as follows: (1) high SBM and low level of l-Lys HCl (HSBM), (2) high l-Lys HCl and moderate Ile, Val, Trp (AA above NRC 2012 estimates; NC), (3) moderate l-Lys HCl and high Ile, Val, and Trp (PC), and PC with either increased (4) L-Val (PC+Val), (5) L-Ile (PC+Ile), or (6) L-Trp (PC+Trp). Pigs fed the NC diet were predicted to have the poorest average daily gain (ADG), the PC diet to be intermediate, and pigs fed the HSBM, PC+Val, PC+Ile, and PC+Trp have the same and highest predicted ADG. In the grower period (34 to 90 kg), ADG was greater (Ρ < 0.05) for the pigs fed HSBM and PC+Val diets than the NC with pigs fed other diets intermediate. Pigs fed HSBM were more (Ρ < 0.05) efficient (G:F) than the NC and PC with pigs fed other diets intermediate. In the finisher period (90 to 136 kg), ADG was greater (Ρ < 0.05) for pigs fed PC+Ile than that of the NC with pigs fed other diets intermediate. Pigs fed PC+Val had greater (Ρ < 0.05) average daily feed intake (ADFI) than the NC with pigs fed other diets intermediate. However, PC+Ile pigs were more (Ρ < 0.05) efficient than PC+Val with pigs fed other diets intermediate. Overall, ADG was greater (Ρ < 0.05) for pigs fed HSBM, PC+Val, and PC+Ile diets than the NC with pigs fed other diets intermediate. Pigs fed the PC+Val diet had greater (Ρ < 0.05) ADFI than the NC with pigs fed other diets intermediate. No differences were detected between treatments for overall G:F or other carcass characteristics. In conclusion, increasing Val or Ile in high l-Lys-HCl-DDGS-based diets improved growth performance compared with pigs fed diets containing high levels of l-Lys HCl without added Val and Ile. These results present evidence that the recently developed meta-analysis can predict the relative differences in overall ADG for pigs fed the NC, PC, PC+Val, and PC+Ile diets; however, the predicted G:F was less accurate. The data demonstrate that the negative effects of high Leu concentrations in corn-DDGS-based diets can be reversed by increasing the ratios of Val and Ile relative to Lys.     

Morphological changes during the transition from freshwater to sea water in an amphidromous goby,Sicyopterus lagocephalus (Pallas 1770) (Teleostei)

The widely distributed amphidromous goby Sicyopterus lagocephalus needs drastic change of habitat to fulfil its life cycle: adults live and spawn in rivers, where eggs hatch into prolarvae that have to reach the sea to acquire characteristics of planktonic larvae. Postlarvae return to rivers where they recruit and grow to the adult reproductive stage. Here, we describe the prolarval stages, namely from hatching to first contact with sea water, as well as the first marine larval stages. The observations were made under experimental conditions. We described 3 prolarval substages in freshwater (L1a–L1c). Prolarvae present a slight but visible ontogenetic development in freshwater, during which the yolk sac begins to reduce, the pigmentation increases on the body and in the eyes, and the lenses appear, although the eyes are not functional. Prolarvae need to reach the sea in a maximum of 96 h to pursue their development. Their transfer in sea water at a salinity of 36.5 induces important morphological modifications (i.e. yolk sac full absorption, appearance of pectoral fins, migration of the eyes in anterolateral position of the head, opening of mouth and anus), enabling the organisms to adapt to their new environment. This marine stage is divided into two substages: L2a corresponding to the organisation of the morphological structures adapted to the marine environment and L2b during which these morphological structures become functional. Whether it is in freshwater or sea water, the duration of the substages depends on the water temperature, but is similar for all individuals for a given temperature.     

Environmental factors regulating the recruitment of walleye Sander vitreus and white bass Morone chrysops in irrigation reservoirs

Understanding the environmental factors that regulate fish recruitment is essential for effective management of fisheries. Generally, first‐year survival, and therefore recruitment, is inherently less consistent in systems with high intra‐ and interannual variability. Irrigation reservoirs display sporadic patterns of annual drawdown, which can pose a substantial challenge to recruitment of fishes. We developed species‐specific models using an 18‐year data set compiled from state and federal agencies to investigate variables that regulate the recruitment of walleye Sander vitreus and white bass Morone chrysops in irrigation reservoirs in south‐west Nebraska, USA. The candidate model set for walleye included only abiotic variables (water‐level elevation, minimum daily air temperature during winter prior to hatching, annual precipitation, spring warming rate and May reservoir discharge), and the candidate model set for white bass included primarily biotic variables (catch per unit effort (CPUE) of black crappie Pomoxis nigromaculatus, CPUE of age‐0 walleye, CPUE of bluegill Lepomis macrochirus and CPUE of age‐3 and older white bass), each of which had a greater relative importance than the single abiotic variable (minimum daily air temperature during winter after hatching). Our findings improve the understanding of the recruitment of fishes in irrigation reservoirs and the relative roles of abiotic and biotic factors.     

The science/policy interface in logic-based evaluation of forest ecosystem sustainability

Numerous efforts around the world are underway to apply the Montreal criteria and indicators to assess the sustainability of temperate and boreal forests. In this paper, we describe a logic-based system for evaluating the sustainability of forests at regional and national levels. We believe that such a system can make evaluation of sustainability more consistent and transparent. This effort also makes two points abundantly clear: (1) a systematic way to organize expert judgment about ecological, economic, social and institutional relationships (here, using ‘fuzzy logic’) is crucial to building such a system and (2) that the structure of this logic-based system reflects a policy framework and a series of decisions about values and what is meant by ‘sustainability’.     

转型中的亚洲林业(续二)

在过去的20年里,亚洲林业经历了引人注目的转型,包括从计划经济到市场经济的转变,从天然林供给木材到人工林供给木材的转变,木材替代品与非木质林产品的增加,地方分权与当地群众的参与,生态时代的发展与生态系统管理。在促进亚洲可持续森林资源管理中,市场工具、社区参与和环境服务都得到了应用。亚洲林业的转型表现出多样化,其森林、社会与环境之间的联系是丰富多彩的。     

Application of modal-based damage-detection method to locate and evaluate damage in timber beams

Modal-based damage-detection algorithms were used to identify the location of defects commonly found in timber and to estimate their severities. In this study, the authors propose modifications to an existing damage-detection algorithm for locating and evaluating damage by comparing the modal strain energy before and after damage using the first two flexural modes of vibration. Experimental verification was performed on pin-pin supported timber beams by employing the algorithms with extracted modal parameters using experimental modal analysis. Single and multiple cases of damage used to simulate pocket(s) of rot with various severities were inflicted by removing sections of timber beam specimens. The proposed damage indicator, computed from the first two flexural modes, was capable of detecting all damage locations. It was also able to estimate, with reasonable accuracy, the severity of damage in term of loss of sectional moment of inertia. The modified damage index method is generally reliable in detecting the location and estimating the severity of simulated defects in timber beams.     

Expression of Marek's disease virus phosphorylated polypeptide pp38 produces splice variants and enhances metabolic activity

The phosphorylated polypeptide (pp)38 of oncogenic Marek's disease (MD) herpesvirus (MDV) is expressed during lytic infections in vivo and in vitro, but its functions have not been fully elucidated. The quail cell line QT-35, latently infected with MDV, was used to generate QTP32 in which pp38 is expressed under control of a tetracycline controlled promoter to examine possible functions of pp38. Induction of pp38 did not influence late MDV genes expression, but it enhanced mitochondrial dehydrogenase activity significantly. Two new pp38 splice variants were found in induced QTP32 cells, in additional in vitro systems and MDV-infected chickens. Differential expression of full-length pp38 and splice variants suggests that the splice variants are important during latency and perhaps transformation. Polypeptides of 40 and 20kDa were detected by Western blot using monoclonal antibody H19. These polypeptides were also produced in DF-1 cells transfected with a pp38 construct in which the splice acceptor sites had been mutated. Our results add important new information to the role of pp38 in the pathogenesis of MD. The data suggest that pp38 and the two newly described splice variants may influence metabolic activity, which may have important consequences for the understanding of latency and tumor development.     

Do mothers understand healthy eating principles for low-birth-weight infants?

OBJECTIVES: To describe feeding patterns and mothers' perceptions of desirable feeding practices in low-birth-weight (LBW) infants after hospital discharge in England and to test for the association of inappropriate practices/perceptions with identifiable demographics. DESIGN: Postal questionnaires from 198 mothers of LBW infants in London, Liverpool and Winchester were analysed regarding infant demographics, mothers' demographics, infant milks used, solid feeding practices and mothers' perceptions of infant feeding practices. RESULTS: At birth, the median weight, independent of gestational age, was 1.80 kg (range 0.6-2.50 kg) and 37.1% of infants received breast milk exclusively; 83.7% were breast-fed at some stage, a practice favoured more by first-time mothers (90.2%) than multiparous mothers (73.4%) (P = 0.004) as well as by mothers of higher social groups (P = 0.019). The median age of solid food introduction was 17 postnatal weeks (range 8-36 weeks); the timing correlated strongly with infant birth weight (P < 0.001). A high-fibre diet and a low-fat diet were incorrectly considered important for their infants by 67.1% and 51.6% of mothers, respectively. Regarding a high-fibre diet as important was associated with being a multiparous mother (P = 0.006), while regarding a low-fat diet as important was associated with low social group (P = 0.018). A quarter of mothers did not consider 'plenty of calories' to be important for their infants, reflecting similar attitudes in 1990 for mothers of term infants; this incorrect attitude exhibited an association with being a first-time mother (P = 0.047). CONCLUSIONS: Infant feeding practices were very variable, showing poor concordance with national and international recommendations for term infants. In selecting foods for their infants, many mothers appeared to be applying principles more appropriate to planning a healthy diet for adults. There is an urgent need to develop and implement evidence-based guidelines for feeding LBW infants after hospital discharge, with special attention given to multiparous mothers as well as mothers from lower social groups.     

Irreversible organic crystalline chemistry monitored in real time

Because multiple laser shots are typically required to monitor ultrafast photochemical reaction dynamics, sample depletion and product accumulation have greatly restricted the range of substrates and structural environments amenable to study. By implementing a two-dimensional spatial delay gradient across the profile of a femtosecond probe pulse, we can monitor in a single laser shot organic crystalline reaction dynamics despite the formation of permanent photoproducts that cannot be conveniently removed. We monitored the photolysis of the triiodide anion, I3-, and subsequent recombination or relaxation of its reaction products, in three very different pure organic molecular crystals. The experimental results and associated molecular dynamics simulations illustrate the intimate connection between lattice structure and reaction dynamics, highlighting the role of lattice constraints in directing phase-coherent geminate recombination of photofragments within a crystalline reaction cage.