3,085 research outputs found
Practical inference from industrial split-plot designs.
Many industrial response surface experiments are deliberately not conducted in a completely randomized fashion. This is because some of the factors investigated in the experiment are hard to change. The resulting experimental design then is of the split-plot type and the observations in the experiment are in many cases correlated. A proper analysis of the experimental data therefore is a mixed model analysis involving generalized least squares estimation. Many people, however, analyze the data as if the experiment was completely randomized, and estimate the model using ordinary least squares. The purpose of the present paper is to quantify the differences in conclusions reached from the two methods of analysis and to provide the reader with guidance for analyzing split-plot experiments in practice. The problem of choosing the number of degrees of freedom for significance tests in the mixed model analysis is discussed as well.Containment method; Data; Design; Experimental design; Factors; Fashion; Generalized least squares; Least-squares; Method of Kenward and Roger; Methods; Model; Ordinary least squares; Residual method; Satterthwaite's method; Split-plot experiment; Squares;
Effect of afterbody geometry and sting diameter on the aerodynamic characteristics of slender bodies at mach numbers from 1.57 to 2.86
Afterbody geometry and sting diameter effect on aerodynamics of slender bodies at supersonic spee
Signals generating anorexia during acute illness: Symposium on ‘Eating, illness and the gut: is there disorder in the house?'
Anorexia is part of the body's acute-phase response to illness. Microbial products such as lipopolysaccharides (LPS), which are also commonly used to model acute illness, trigger the acute-phase response and cause anorexia mainly through pro-inflammatory cytokines. LPS stimulate cytokine production through the cell-surface structural molecule CD14 and toll-like receptor-4. Cytokines ultimately change neural activity in brain areas controlling food intake and energy balance. The blood-brain barrier endothelial cells (BBB EC) are an important site of cytokine action in this context. BBB EC and perivascular cells (microglia and macrophages) form a complex regulatory interface that modulates neuronal activity by the release of messengers (e.g. PG, NO) in response to peripheral challenges. Serotonergic neurons originating in the raphe nuclei and glucagon-like peptide-1-expressing neurons in the hindbrain may be among the targets of these messengers, because serotonin (5-HT), acting through the 5-HT2C receptor, and glucagon-like peptide-1 have recently emerged as neurochemical mediators of LPS anorexia. The central melanocortin system, which is a downstream target of serotonergic neurons, also appears to be involved in mediation of LPS anorexia. Interestingly, LPS also reduce orexin expression and the activity of orexin neurons in the lateral hypothalamic area of fasted mice. As the eating-stimulatory properties of orexin are apparently related to arousal, the inhibitory effect of LPS on orexin neurons might be involved in LPS-induced inactivity and anorexia. In summary, the immune signalling pathways of LPS-induced, and presumably acute illness-induced, anorexia converge on central neural signalling systems that control food intake and energy balance in healthy individual
On the use of multicriteria decision analysis to formally integrate community values into ecosystem‐based freshwater management
Freshwater ecosystems are essential to peoples' economic, cultural, and social well-being, yet are still among the most threatened ecosystems on the planet. Consequently, a plethora of recent regulations and policies seek to halt the loss of restore or safeguard freshwaters, their biodiversity, and the ecosystem services they provide. Ecosystem-based management (EBM), an approach that considers human society as an integral part of ecosystems, is increasingly being promoted to help meet this challenge. EBM involves an overarching regulatory framework and local solutions with trade-offs and compromises factors that not only make decision processes complex but also provide the means for combining top down regulation with bottom-up priorities into collaborative management strategies. Although stakeholder participation is encouraged in most modern freshwater management, community values are often largely neglected. Here, we introduce a well-known participatory decision support framework based on multicriteria decision analysis (MCDA) to operationalize EBM and promote community-inclusive decision making in freshwater management. We explain the different steps that this approach comprises, which lead to the prioritization of a management strategy in a collaborative way. We also show how cultural values that inherently embed strong links between the environment and people can be used together with typical ecological and socio-economic values. We illustrate the MCDA-based EBM-approach for New Zealand, one of the few countries in which regional freshwater management is mandated to uphold environmental quality standards, while safeguarding local community values and ecosystem services. Finally, we discuss some of the challenges, which are increasingly emerging as a result of mandated community collaboration in environmental management. © 2018 John Wiley & Sons, Ltd.Simone Langhans has received funding from the European Unio
Tanniferous forage plants with anthelmintic properties: the example of sainfoin (Onobrychis viciifolia)
Introduction: Sainfoin is a high-quality condensed tannin containing forage plant. The knowledge about anthelmintic effects against sheep nematodes and about the influence of plant preservation (e.g. ensiling) on the anthelmintic activity is limited.
Method: 36 parasite naïve lambs (6 groups of 6 animals each) were infected with H. contortus (7,000 L3) and C. curticei (15,000 L3). From day 28 until day 44 p.i., groups A1, B1 and C1 received fresh, dried or ensiled sainfoin. Groups A2, B2 and C2 served as respective tannin-free controls. Individual faecal egg counts on a dry matter basis (FECDM) were performed every 3-4 days. On day 44, all animals were slaughtered and adult worm populations were determined.
Results: The consumption of sainfoin was associated with a reduction of adult H. contortus (35% (P<0.1), 47% (P<0.05) and 49% (P<0.1) for fresh, dried and ensiled sainfoin, respectively) but had little effect on adult C. curticei. Compared to the controls, H. contortus specific FECDM was reduced by 62% (P<0.05), 58% (P<0.01) and 48% (P<0.1) for fresh, dried and ensiled sainfoin. FECDM specific to C. curticei were decreased by sainfoin hay and silage (hay 81% , silage 74%, both tests P<0.001) but were unchanged when fresh sainfoin was administered.
Conclusion: For H. contortus the FECDM decrease seemed to be due to a nematocidal effect towards adult H. contortus. In contrast for C. curticei, the reduction in FECDM appeared to be a result of a reduced per capita fecundity. The use of conserved tanniferous fodder offers promising perspectives as a complementary control approach against nematodes in sheep
Effect of sainfoin (Onobrychis viciifolia) silage and hay against gastrointestinal nematodes in lambs
The objective of the study was to examine the effect of dried and ensiled sainfoin (Onobrychis viciifolia) against two species of gastrointestinal nematodes (Haemonchus contortus, Cooperia curticei) in lambs. Twenty-four days post experimental infection, 24 lambs were allocated to 4 equal groups. Group A and B received sainfoin silage and control silage respectively for 16 days. Groups C and D were fed on sainfoin hay or control hay for the same period. Feeds were administered ad libitum and mean refusals and live weight were regularly recorded. Individual faecal egg counts (FEC) were performed twice weekly. After the feeding period all lambs were slaughtered for post mortem investigation. The consumption of sainfoin hay was associated with a significant reduction of the adult H. contortus burden by 47 % (P < 0.05) whereas no significant difference was seen when feeding sainfoin silage (49 %, P = 0.112). The C. curticei worm burden was not significantly reduced by either sainfoin hay or silage. At slaughter FEC were significantly reduced by sainfoin hay by 64 % (P < 0.001) compared to the control feed. After feeding sainfoin silage FEC decreased by 48 % (P = 0.056). There was a tendency of better live weight gain in sainfoin hay fed animals compared to the control fed ones (P=0.07). These results demonstrate a nematocidal effect of a tanniferous forage legume against gastrointestinal nema¬¬todes, which was more pronounced against H. contortus. The antiparasitic effects were largely preserved when feeding sainfoin silage, suggesting this conservation procedure to be a valuable alternative to hay
Numerical simulations of sunspots
The origin, structure and evolution of sunspots are investigated using a numerical model. The compressible MHD equations are solved with physical parameter values that approximate the top layer of the solar convection zone. A three dimensional (3D) numerical code is used to solve the set of equations in cylindrical geometry, with the numerical domain in the form of a wedge. The linear evolution of the 3D solution is studied by perturbing an axisymmetric solution in the azimuthal direction. Steady and oscillating linear modes are obtained
Aerodynamic characteristics in pitch of a 1/7-scale model of a two- and three-stage rocket configuration at Mach numbers of 0.4 to 4.63
Aerodynamic characteristics in pitch of scale model of two and three stage rocket configuration at Mach numbers of 0.4 to 4.6
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