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.

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

Evolutionary art with an EEG fitness function

This project involved the use of an interactive Genetic Al-gorithm (iGA) with an electroencephalogram (EEG)-based fitness function to create paintings in the style of Piet Mondrian, a Dutch painter who used geometric elements in his later paintings. Primary data for the prototype was gathered by analysis of twenty-seven existing Mondrian paintings. An EEG gaming headset was used to read EEG signals, which were transmitted by Bluetooth to an Arduino running an iGA. These values were used as the iGA fitness function. The data was sent to a PC running Processing to dis-play the artwork. The resultant displayed artwork evolves to favour higher attention and meditation levels, which are considered to represent greater mindfulness. The process ends when the observer identifies a piece of art they would like to keep. However, convergence of the algorithm is difficult to test as many parameters can affect the process. A number of issues aris-ing from the research are discussed and further work is proposed

Judicial Review of Federal Administrative Action: Quest for the Optimum Forum

Professors Currie and Goodman present a comprehensive analysis of the variables that must be isolated and weighed in determining the optimum forum for judicial review of administrative action. While the backdrop for this study is the caseload crisis presently confronting the federal courts of appeals, their discussion illuminates the requisites for optimum judicial review generally. Failing to perceive any compelling reason to single out administrative cases for review in separate courts, the authors argue against the creation of special administrative appeals courts. Even if such courts were to enjoy broad subject matter jurisdiction over the most demanding aspects of the agency review caseload, countervailing considerations, such as the danger of improper influence on the appointment process and the loss of the judges\u27 generalist perspective, outweigh the perceived benefits of uniformity, expertise and relief for the regional courts of appeals. As to the optimal forum within the present system of district courts and courts of appeals, the authors divide their discussion into three categories of agency action. With respect to formal agency determinations, the authors generally favor direct appellate court review, except where diversion to the district courts in the first instance is necessary to reduce an appellate workload which has grown to such proportions that it threatens the collegial nature of circuit court decisionmaking; and among two-tier systems, the authors suggest that discretionary appellate review be limited to areas generating a burdensome volume of appeals, involving issues or interests of relative insignificance and not bearing a potential for biased or misguided trial court decisions. Informal rulemaking, generally involving issues of legal importance which are likely to ultimately reach the courts of appeals in any event, is presumptively appropriate for direct appellate review. Despite the absence of a trial-type record, the courts of appeals will not have to engage in extensive factfinding, for any factual issues will increasingly be determined on the basis of materials before the agency, and any need for new factual information will be rare and obtainable by methods short of a judicial trial. In the case of informal .adjudication, however, the absence of a formal adjudicative record justifies a presumption in favor of initial district court review. Informal rulemaking is distinguished, for the issues arising from informal adjudication are likely to involve questions of specific fact, there is little guarantee of any meaningful record for review, and a larger proportion of such determinations are relatively unimportant and unlikely to be taken to the courts of appeals. The authors recognize that direct circuit court review may be appropriate if review is limited to reconstruction of the record before the agency and there is therefore no significant factfinding burden

Judicial Review of Federal Administrative Action: Quest for the Optimum Forum

Professors Currie and Goodman present a comprehensive analysis of the variables that must be isolated and weighed in determining the optimum forum for judicial review of administrative action. While the backdrop for this study is the caseload crisis presently confronting the federal courts of appeals, their discussion illuminates the requsites for optimum judicial review generally. Failing to perceive any compelling reason to single out administrative cases for review (in separate courts, the authors argue against the creation of special administrative appeals courts. Even if such courts were to enjoy broad subject matter jurisdiction over the most demanding aspects of the agency review caseload, countervailing considerations, such as the danger of improper influence on the appointment process and the loss of the judges\u27 generalist perspective, outweigh the perceived benefits of uniformity, expertise and relief for the regional courts of appeals. As to the optimal forum within the present system of district courts and courts of appeals, the authors divide their discussion into three categories of agency action. With respect to formal agency determinations, the authors generally favor direct appellate court , except where diversion to the district courts in the first instance ·is necessary to reduce an appellate workload which has grown to such proportions that threatens the collegial nature of circuit court decision making; and among two-tier systems, the authors suggest that discretionary appellate review be limited to areas generating a burdensome volume of appeals, involving issues or interests of relative insignificance and not bearing a potential for biased or misguided trial court decisions. Informal rule making , generally involving; issues of legal importance which are likely to ultimately reach the courts of appeals in any event, is presumptively appropriate for direct appellate review. Despite the absence of a trial-type record, the courts of appeals will not have to engage in extensive fact finding, for any factual issues ·will increasingly be determined on the basis of materials before the agency, and any need for new factual information will be rare and obtainable b;; methods short of a judicial trial. In the case of informal adjudication, however, the absence of a formal adjudicative record justifies a presumption in favor of initial district court review. Informal rule making is distinguished, for the issues arising from informal adjudication are likely to involve questions of specific fact, there is little guarantee of any meaningful record for review, and a larger pro portion of such determinations are relatively unimportant and unlikely to be taken to the courts of appeals. The authors recognize that direct circuit court review may be appropriate if review is limited to reconstruction of the record before the agency and there is therefore no significant fact finding burden

The Kinematic and Chemical Properties of a Potential Core-Forming Clump: Perseus B1-E

We present 13CO and C18O (1-0), (2-1), and (3-2) maps towards the core-forming Perseus B1-E clump using observations from the James Clerk Maxwell Telescope (JCMT), Submillimeter Telescope (SMT) of the Arizona Radio Observatory, and IRAM 30 m telescope. We find that the 13CO and C18O line emission both have very complex velocity structures, indicative of multiple velocity components within the ambient gas. The (1-0) transitions reveal a radial velocity gradient across B1-E of 1 km/s/pc that increases from north-west to south-east, whereas the majority of the Perseus cloud has a radial velocity gradient increasing from south-west to north-east. In contrast, we see no evidence of a velocity gradient associated with the denser Herschel-identified substructures in B1-E. Additionally, the denser substructures have much lower systemic motions than the ambient clump material, which indicates that they are likely decoupled from the large-scale gas. Nevertheless, these substructures themselves have broad line widths (0.4 km/s) similar to that of the C18O gas in the clump, which suggests they inherited their kinematic properties from the larger-scale, moderately dense gas. Finally, we find evidence of C18O depletion only toward one substructure, B1-E2, which is also the only object with narrow (transonic) line widths. We suggest that as prestellar cores form, their chemical and kinematic properties are linked in evolution, such that these objects must first dissipate their turbulence before they deplete in CO.Comment: Accepted by ApJ, 34 pages, 12 figure

Palmer Amaranth (Amaranthus palmeri) Suppression with Half Rates of Dicamba and Atrazine with Increasing Sorghum (Sorghum bicolor) Density and Nitrogen Rate

Palmer amaranth (PA) competition can result in severe yield loss in grain sorghum. Increasing sorghum density and nutrient supply could promote early/rapid canopy closure and therefore reduce the amount of light that could otherwise penetrate the canopy and promote PA growth in sorghum. A study was conducted at the Southwest Research-Extension Center near Garden City, KS, to determine if PA could be suppressed with dicamba and atrazine applied as PRE at half rates combined with increasing sorghum density (60,000, 90,000, and 120,000 seeds/a), and nitrogen rate (0, 100, 200 lb/a). Preliminary results indicate that increasing plant density and nitrogen rate did not suppress PA growth. The increase in plant density and nitrogen (N) rate had no affect on reducing PA height, number, and biomass in plots without in-season control (hoeing). In-season control of Palmer amaranth significantly (P \u3c 0.01) increased grain yield, sorghum height and number of heads, and was required to maximize yield. These results suggest that increasing plant density within the row does not reduce light penetration into sorghum canopy to suppress PA growth. Therefore, narrow-row planting will be added to the treatment structure to further determine the effect of plant density on suppressing PA in irrigated sorghum production

Late-summer biogeochemistry in the Mertz Polynya: East Antarctica

A marked reconfiguration of the Mertz Polynya following the 2010 calving of the Mertz Glacier Tongue has been associated with a decrease in the size and activity of the polynya. We report observations of the oceanic carbonate (CO2) system in late-summer 2013, the third post-calving summer season. Estimates of seasonal net community production (NCP) based on inorganic carbon deficits and the oxygen-argon ratio indicate that the waters on the shelf to the east of Commonwealth Bay (adjacent to the Mertz Glacier) remain productive compared to pre-calving conditions. The input of residual or excess alkalinity from melting sea ice is found to contribute to the seasonal enhancement of carbonate saturation state and pH in shelf waters. Mean rates of NCP in 2012-2013 are more than twice as large as those observed in the pre-calving summers of 2001 and 2008 and suggest that the new (post-calving) configuration of the polynya favors enhanced net community production and a stronger surface ocean sink for atmospheric CO2 due at least in part to the redistribution of sea ice and associated changes in summer surface stratification