Semiparametric models and P-splines

P-splines were introduced by Eilers and Marx (1996). We consider semiparametric models where the smooth part of the model can be described by P-splines. A mixed model representation is also considered. We set a simple strategy for the choice of P-spline parameters, ndx, bdeg and pord, and discuss the use of various criteria for smoothing parameter selection. We illustrate our remarks with the analysis of a randomised block design

SEMIPARAMETRIC MODELS AND P-SPLINES

P-splines were introduced by Eilers and Marx (1996). We consider semiparametric models where the smooth part of the model can be described by P-splines. A mixed model representation is also considered. We set a simple strategy for the choice of P-spline parameters, ndx, bdeg and pord, and discuss the use of various criteria for smoothing parameter selection. We illustrate our remarks with the analysis of a randomised block design.

Contingent plan structures for spacecraft

Most current AI planners build partially ordered plan structures which delay decisions on action ordering. Such structures cannot easily represent contingent actions. A representation which can is presented. The representation has some other useful features: it provides a good account of the causal structure of a plan, can be used to describe disjunctive actions, and it offers a planner the opportunity of even less commitment than the classical partial order on actions. The use of this representation is demonstrated in an on-board spacecraft activity sequencing problem. Contingent plan execution in a spacecraft context highlights the requirements for a fully disjunctive representation, since communication delays often prohibit extensive ground-based accounting for remotely sensed information and replanning on execution failure

An archival case study : revisiting the life and political economy of Lauchlin Currie

This paper forms part of a wider project to show the significance of archival material on distinguished economists, in this case Lauchlin Currie (1902-93), who studied and taught at Harvard before entering government service at the US Treasury and Federal Reserve Board as the intellectual leader of Roosevelt's New Deal, 1934-39, as FDR's White House economic adviser in peace and war, 1939-45, and as a post-war development economist. It discusses the uses made of the written and oral material available when the author was writing his intellectual biography of Currie (Duke University Press 1990) while Currie was still alive, and the significance of the material that has come to light after Currie's death

The Evolution of Protoplanetary Disks Around Millisecond Pulsars: The PSR 1257 +12 System

We model the evolution of protoplanetary disks surrounding millisecond pulsars, using PSR 1257+12 as a test case. Initial conditions were chosen to correspond to initial angular momenta expected for supernova-fallback disks and disks formed from the tidal disruption of a companion star. Models were run under two models for the viscous evolution of disks: fully viscous and layered accretion disk models. Supernova-fallback disks result in a distribution of solids confined to within 1-2 AU and produce the requisite material to form the three known planets surrounding PSR 1257+12. Tidal disruption disks tend to slightly underproduce solids interior to 1 AU, required for forming the pulsar planets, while overproducing the amount of solids where no body, lunar mass or greater, exists. Disks evolving under 'layered' accretion spread somewhat less and deposit a higher column density of solids into the disk. In all cases, circumpulsar gas dissipates on $\lesssim 10^{5}$ year timescales, making formation of gas giant planets highly unlikely.Comment: 16 pages, 17 figures, Accepted for publication in The Astrophysical Journal (September 20, 2007 issue

Time and dose-dependent effects of phenobarbital on the rat liver miRNAome.

In a previous study we had shown that treatment of male Fischer rats with exogenous chemicals for three months resulted in prominent, mode-of-action dependent effects on liver microRNA (miRNA) (Koufaris et al., 2012). Here we investigated how the effects of chemicals on liver miRNA in male Fischer rats relate to the length and dose of exposure to phenobarbital (PB), a drug with multiple established hepatic effects. Importantly, although acute PB treatment (1-7 days) had significant effects on liver mRNA and the expected effects on the liver phenotype (transient hyperplasia, hepatomegaly, cytochrome P450 induction), limited effects on liver miRNA were observed. However, at 14 days of PB treatment clear dose-dependent effects on miRNA were observed. The main effect of PB treatment from days 1 to 90 on liver miRNA was found to be the persistent, progressive, and highly correlated induction of the miR-200a/200b/429 and miR-96/182 clusters, occurring after the termination of the xenobiotic-induced transient hyperplasia. Moreover, in agreement with their reported functions in the literature we found associations between perturbations of miR-29b and miR-200a/200b by PB with global DNA methylation and zeb1/zeb2 proteins respectively. Our data suggest that miRNA are unlikely to play an important role in the acute responses of the adult rodent liver to PB treatment. However, the miRNA responses to longer PB exposures suggest a potential role for maintaining liver homeostasis in response to sub-chronic and chronic xenobiotic-induced perturbations. Similar studies for more chemicals are needed to clarify whether the temporal and dose pattern of miRNA-toxicant interaction identified here for PB are widely applicable to other xenobiotics. © 2013 Elsevier Ireland Ltd

Infectious bronchitis virus infections of chickens in Belgium : an epidemiological survey

Between April 2012 and July 2015, cloacal and/or tracheal swab samples were collected from four hundred and twenty-four Belgian chicken broiler, breeder and layer flocks. All flocks were kept for production purposes and presented clinical signs suggestive of an infectious bronchitis virus (IBV) infection. The samples were analyzed by real-time polymerase chain reaction (RT-qPCR) to detect the presence of ribonucleic acid (RNA) of IBV. When positive, approximately four hundred base pairs (bp) encoding for the hypervariable region of the IBV S1 protein were sequenced. Sequencing results, cycle threshold (Ct) values and vaccination history were used as criteria to try and distinguish vaccine strains from field strains. Of all samples examined, 22.4% was negative. In 16.4% of the samples that did contain RNA from IBV, the genotype could not be determined. In most cases, this was due to the recovery of RNA quantities below the lower limit of detection of the sequencing PCR. The remaining positive submissions predominantly revealed RNA from IBV strains that belonged to the 4/91-793B (46.8%), D388-QX (25.2%), D274-D207 (5.8%) and Massachusetts (4.0%) genotypes. Estimations indicated that approximately 58%, 11%, 37% and 46% of these detections, respectively, were vaccine strains. Infections with types CK/CH/Guandong/Xindadi/0903, Ukr/27/2011, NGA/295/2006 and Q1 were observed sporadically. The results indicate that IBV infections are highly prevalent in Belgian chickens and that at least eight different IBV types were circulating during the monitored period. This underlines the necessity of providing flocks with a strong and broad protective immunity against IBV

Are you serious? From fist bumping to hand hygiene: considering culture, context and complexity in infection prevention intervention research

Infection prevention is an under-resourced research and development topic, with limited evidence for practice in the most basic of measures. A survey of IPS R&D members indicated that what might appear to be simple interactions and interventions in healthcare, such as hand shaking and hand hygiene, should be considered complex interventions taking account of behaviour at the individual and social level as well as contextual factors. Future studies need to be designed utilising comprehensive approaches, for example, the Medical Research Council complex interventions framework, tailored to the country and more local cultural context, if we are to be serious about evidence for infection prevention and control practice

Analysis of B and Be Star Populations of the Double Cluster h and chi Persei

We present blue optical spectra of 92 members of h and chi Per obtained with the WIYN telescope at Kitt Peak National Observatory. From these spectra, several stellar parameters were measured for the B-type stars, including V sin i, T_eff, log g_polar, M_star, and R_star. Stromgren photometry was used to measure T_eff and log g_polar for the Be stars. We also analyze photometric data of cluster members and discuss the near-to-mid IR excesses of Be stars.Comment: 4 pages, to appear in the proceedings of IAU Symposium 266: Star Cluster