bluuebunny/crossref_metadata_2025 huggingface dataset:
A porous layer: an evidence for the deterioration of MOVPE InN grown at high temperature (∼650 °C)
Authors: Sugita K. , Hashimoto A. , Yamamoto A.
Published: March 2009

This paper indicates an evidence for the deterioration of the MOVPE InN during the growth at high temperature (∼650 °C). It is noted that the deterioration occurs near the interface and InN film becomes porous layer during the further growth. The porous layer has high electron density. The rate‐limiting process of N‐face InN decomposition depends on atomic hydrogen. The atomic hydrogen produced by the decomposition of NH3 is responsible for the deterioration of InN film. The crystal quality of InN improves with decreasing the porous layer which is important for MOVPE InN. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Homogeneous and inhomogeneous linewidth broadening of single polar GaN/AlN quantum dots
Authors: Demangeot F. , Simeonov D. , Dussaigne A. , Butté R. , Grandjean N.
Published: March 2009

We report on the dependence on temperature of the homogeneous and inhomogeneous broadening of the fundamental transition of single polar GaN/AlN quantum dots (QDs). Stranski‐Krastanov QDs have been grown by molecular beam epitaxy using NH3 as a nitrogen source, with a very low surface density. Low temperature (LT) microphotoluminescence measurements have been performed on 200 nm wide mesas in order to isolate the luminescence of single QDs. The linewidth is found to vary from 590 μeV at 4 K up to 1350 μeV at 65 K in a dot of 6 monolayer height. Though the LT linewidth is still dominated by spectral diffusion, the temperature dependent broadening up to 50 K is mainly accounted for by interactions between excitons and acoustic phonons through a coupling coefficient value nearly two orders of magnitude larger than its counterpart in InAs QDs. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Mass spectrometric characterization of 4‐oxopentanoic acid and gas‐phase ion fragmentation mechanisms studied using a triple quadrupole and time‐of‐flight analyzer hybrid system and density functional theory
Authors: Kanawati Basem , Joniec Seweryn , Winterhalter Richard , Moortgat Geert K.
Published: March 2009

4‐Oxopentanoic acid was characterized experimentally by electrospray ionization using a triple quadrupole and time‐of‐flight analyzer hybrid system. This compound was chosen as a model substance for small organic compounds bearing an acetyl and a carboxyl group. Collision‐induced dissociation experiments at different activation energies were performed to elucidate possible fragmentation pathways. These pathways were also studied on the theoretical level using density functional theory (DFT) B3LYP/6‐311++G(3df,3pd)//B3LYP/6‐31+G(d)+ZPVE calculations. CO2 ejection from the [M–H]− anion of 4‐oxopentanoic acid was observed and the fragmentation pathway studied by DFT reveals a new concerted mechanism for CO2 elimination accompanied by an intramolecular proton transfer within a pentagonal transition state structure. Successive elimination of water and CO from the [M–H]− anion of 4‐oxopentanoic acid was also observed. A rearrangement in the primary deprotonated ketene anion produced after water elimination was found on the theoretical level and leads to CO elimination from the primary product anion [M–H–H2O]−. Energy diagrams along the reaction coordinates of the fragmentation pathways are presented and discussed in detail. Mulliken charge distributions of some important structures are presented. Copyright © 2008 John Wiley & Sons, Ltd.
From medical image computing to computer‐aided intervention: development of a research interface for image‐guided navigation
Authors: Papademetris Xenophon , DeLorenzo Christine , Flossmann Sven , Neff Markus , Vives Kenneth P. , Spencer Dennis D. , Staib Lawrence H. , Duncan James S.
Published: March 2009

Background

This paper describes the development and application of a research interface to integrate research image analysis software with a commercial image‐guided surgery navigation system. This interface enables bi‐directional transfer of data such as images, visualizations and tool positions in real time.

Methods

We describe both the design and the application programming interface of the research interface, as well as showing the function of an example client program. The resulting interface provides a practical and versatile link for bringing image analysis research techniques into the operating room (OR).

Results

We present examples from the successful use of this research interface in both phantom experiments and real neurosurgeries. In particular, we demonstrate that the integrated dual‐computer system achieves tool‐tracking performance that is comparable to the more typical single‐computer scenario.

Conclusions

Network interfaces for this type are viable solutions for the integration of commercial image‐guided navigation systems and research software. Copyright © 2009 John Wiley & Sons, Ltd.
DEA‐based efficiency evaluation of a novel robotic system for femoral neck surgery
Authors: Wang Yu , Yun Chao , Hu Lei , Liu Wenyong , Luan Sheng
Published: March 2009

Background

Efficiency evaluation is important for expanding the acceptance and deployment of medical robots, but it is still an open issue. In this study, a data envelopment analysis (DEA)‐based method was proposed and implemented with a novel robotic system for femoral neck surgery.

Methods

Femoral neck surgeries with and without the assistance of the robotic system were modelled as decision‐making units (DMUs). C2R model was chosen to calculate the relative efficiency.

Results

Clinical simulation experiments were performed with 12 Sawbone models and 24 cadaveric femurs, and 19 clinical cases were chosen to be the control group. The minimum value of the robotically assisted surgery was 1, and the minimum value of the traditional surgery was 0.741535, demonstrating the efficiency of the robotic system.

Conclusion

This research showed that DEA‐based efficiency evaluation is practical for medical robotic systems. Copyright © 2009 John Wiley & Sons, Ltd.
Extraction of knowledge from high strength steel data using soft computing techniques—an overview
Authors: Datta Shubhabrata
Published: March 2009

Soft computing techniques like artificial neural network, fuzzy logic and genetic algorithm are used to extract knowledge from experimentally developed data on the mechanical properties of thermomechanically processed high‐strength steel. Though these techniques, in most case, are used for developing models or optimizing a system, here the additional factor of gathering better understanding of the steel system, under investigation, has also been targeted. The extracted information has been validated by the existing concepts of physical metallurgy of steel. It is seen that these tools have the capability to confirm some of the hypotheses generated through experimentation and could easily be utilized for designing the steel with superior and/or tailor‐made properties. Copyright © 2009 Wiley Periodicals, Inc., A Wiley Company
The Non‐Isotypical Nitride Selenides Dy3NSe3 and Ho3NSe3: Chains and Dimers
Authors: Lissner Falk , Schleid Thomas
Published: March 2009

The non‐isostructural lanthanoid(III) nitride selenides M3NSe3 of dysprosium (Dy3NSe3) and holmium (Ho3NSe3) are formed by the reaction of the respective rare‐earth metal (M = Dy and Ho) with sodium azide (NaN3), selenium and an excess of iodine at 900 °C from torch‐sealed evacuated silica ampoules within seven days. Dy3NSe3 crystallizes orthorhombically (a = 1245.38(9), b = 393.69(3), c = 1303.74(9) pm) in space group Pnma with Z = 4, whereas monoclinic Ho3NSe3 (a = 1152.93(8), b = 1006.61(7), c = 1248.76(9) pm, β = 112.847(3)°) adopts the space group C2/c with Z = 8. Both crystal structures comprise three crystallographically different M3+ cations along with one N3– and three independent Se2– anions, but they differ fundamentally in the linkage of their structure dominating N3–‐centered (M3+)4 tetrahedra. In Dy3NSe3, these [NDy4]9+ units are vertex‐linked to form ∞1{[N(Dy1)1/1t(Dy2)1/1t(Dy3)2/2v]6+} chains (t = terminal, v = vertex‐shared), while just two [NHo4]9+ tetrahedra have one edge in common to join as isolated bitetrahedra ∞0{([N(Ho1)2/2e(Ho2)1/1t‐(Ho3)1/1t]6+)2} (e = edge‐connecting, t = terminal) in Ho3NSe3. So the alternative formula Ho6N2Se6 with Z = 4 is likewisely valid. The M3+ cations in Dy3NSe3 show coordination numbers of six, six plus one and seven, whereas in the case of Ho3NSe3 only coordination numbers of six occur with respect to the anions (N3– and Se2–). In both crystal structures the three independent sorts ofSe2– anions provide the three‐dimensional linkage as well as the charge balance of the ∞1{[NDy3]6+} chains and the ∞0{[N2Ho6]12+} dimers, respectively.
Two Alkali‐Metal Yttrium Tellurides: Single Crystals of Trigonal KYTe2 and Hexagonal RbYTe2
Authors: Babo Jean‐Marie , Schleid Thomas
Published: March 2009

While attempting to synthesize the potassium and rubidium copper diyttrium tetratellurides KCuY2Te4 and RbCuY2Te4 in analogy to CsCuY2Te4 from 1:1:4‐molar mixtures of the elements (copper, yttrium and tellurium) with an excess of KBr or RbBr as flux and potassium or rubidium source, brown plate‐shaped crystals of KYTe2 and RbYTe2 with triangular cross‐section were obtained instead after 14 days at 900 °C in torch‐sealed evacuated silica tubes. These new ternary yttrium tellurides crystallize in the trigonal (KYTe2) or hexagonal system (RbYTe2) with space group R$\bar{3}$m (no. 166) or P63/mmc (no. 194), respectively. With unit cell dimensions of a = 439.51(2) pm, c = 2255.48(9) pm (c/a = 5.132) for KYTe2 and a = 443.26(2) pm, c = 1729.15(7) pm (c/a = 3.901) for RbYTe2, both crystal structures exhibit cadmium‐halide analogous $^{2}_{\infty}\rm \{[YTe_{6/3}]^{-}\}$ layers spreading out parallel to the (001) planes, which are formed by edge‐condensation of the involved [YTe6]9– octahedra (d(Y3+–Te2–) = 308–309 pm). Charge compensation and three‐dimensional linkage of these anionic layers are achieved by monovalent interlayer alkali‐metal cations residing in trigonal antiprismatic (K+ in α‐NaFeO2‐type KYTe2, d(K+–Te2–) = 324 pm, 6×) or prismatic coordination (Rb+ in β‐RbScO2‐type RbYTe2, d(Rb+–Te2–) = 365 pm, 6×) of six Te2– ions each.
Inboard boundary layer state on wind turbine blades
Authors: Dumitrescu H. , Cardoş V.
Published: March 2009

The paper is aimed at describing a fundamental phenomenon: the effect of rotation on the inboard blade boundary layer of a wind turbine. The three‐dimensional incompressible steady momentum integral boundary layer equations coupled with the entrainment equation are used to analyze the inboard stall‐delay due to rotation. Turbulence is modeled by using empirical correlations for the entrainment coefficient and the streamwise skin‐friction coefficient. A power‐law type of velocity profile is assumed for the streamwise turbulent velocity profiles and for cross‐flow velocity profiles the Mager parabolic model is used. The equations are written in cylindrical coordinates and are solved iteratively using a Runge–Kutta scheme. Special attention has been devoted to those term in the differential equations that change the boundary‐layer structure from that of two‐dimensional steady flow. It is concluded that the stall is delayed due to the boundary‐layer reattachment at the inboard sections in conjunction with forming of a spanwise standing vortex structure.
Agreement between Two Independent Groups of Raters
Authors: Vanbelle Sophie , Albert Adelin
Published: March 2009

We propose a coefficient of agreement to assess the degree of concordance between two independent groups of raters classifying items on a nominal scale. This coefficient, defined on a population-based model, extends the classical Cohen’s kappa coefficient for quantifying agreement between two raters. Weighted and intraclass versions of the coefficient are also given and their sampling variance is determined by the Jackknife method. The method is illustrated on medical education data which motivated the research.
Do Electoral Quotas Work after They Are Withdrawn? Evidence from a
Natural Experiment in India
Authors: BHAVNANI RIKHIL R.
Published: March 2009

Do electoral quotas for women alter women's chances of winning elections
after they are withdrawn? I answer this question by examining an unusual
natural experiment in India in which randomly chosen seats in local
legislatures are set aside for women for one election at a time. Using data
from Mumbai, I find that the probability of a woman winning office
conditional on the constituency being reserved for women in the previous
election is approximately five times the probability of a woman winning
office if the constituency had not been reserved for women. I also explore
tentative evidence on the mechanisms by which reservations affect women's
ability to win elections. The data suggest that reservations work in part by
introducing into politics women who are able to win elections after
reservations are withdrawn and by allowing parties to learn that women can
win elections.
Shaping Democratic Practice and the Causes of Electoral Fraud: The Case
of Nineteenth-Century Germany
Authors: ZIBLATT DANIEL
Published: March 2009

Why is there so much alleged electoral fraud in new democracies? Most
scholarship focuses on the proximate cause of electoral competition. This
article proposes a different answer by constructing and analyzing an
original data set drawn from the German parliament's own voluminous record
of election disputes for every parliamentary election in the life of
Imperial Germany (1871–1912) after its adoption of universal male suffrage
in 1871. The article analyzes the election of over 5,000 parliamentary seats
to identify where and why elections were disputed as a result of “election
misconduct.” The empirical analysis demonstrates that electoral fraud's
incidence is significantly related to a society's level of inequality in
landholding, a major source of wealth, power, and prestige in this period.
After weighing the importance of two different causal mechanisms, the
article concludes that socioeconomic inequality, by making elections
endogenous to preexisting social power, can be a major and underappreciated
barrier to the long-term process of democratization even
after the “choice” of formally democratic
rules.
Who Loses in American Democracy? A Count of Votes Demonstrates the
Limited Representation of African Americans
Authors: HAJNAL ZOLTAN L.
Published: March 2009

Critics have long feared that America's winner-take-all electoral system
would undermine the interests of minorities. Unfortunately, few available
tests broadly assess how well minorities fare in a democracy. To gauge
winners and losers in the American case, I introduce a new measure of
representation. For any election, I count up how many voters from each
demographic group vote for a candidate that loses. After comparing this new
measure to its alternatives, I use data from the entire series of Voter News
Service exit polls and a sample of mayoral elections to determine which
kinds of voters end up losers. I find that across the range of American
elections, African Americans are consistently more likely than other groups
to end up losers, raising questions about equity in American democracy. The
one exception to the pattern of black failure—congressional House
elections—suggests ways to better incorporate minority interests.
Nutritional modelling: distributions of salt intake from processed foods in New Zealand
Authors: Thomson Barbara M.
Published: March 2009

The salt content of processed foods is important because of the high intake of Na by most New Zealanders. A database of Na concentrations in fifty-eight processed foods was compiled from existing and new data and combined with 24 h diet recall data from two national nutrition surveys (5771 respondents) to derive salt intakes for seven population groups. Mean salt intakes from processed foods ranged from 6·9 g/d for young males aged 19–24 years to 3·5 g/d for children aged 5–6 years. A total of  ≥ 50 % of children aged 5–6 years, boys aged 11–14 years and young males aged 19–24 years had salt intakes that exceeded the upper limit for Na, calculated as salt (3·2–5·3 g/d), from processed foods only. Bread accounted for the greatest contribution to salt intake for each population group (35–43 % of total salt intake). Other foods that contributed 2 % or more and common across most age groups were sausage, meat pies, pizza, instant noodles and cheese. The Na concentrations of key foods have changed little over the 16-year period from 1987 to 2003 except for corned beef and whole milk that have decreased by 34 and 50 % respectively. Bread is an obvious target for salt reduction but the implication on iodine intake needs consideration as salt is used as a vehicle for iodine fortification of bread.
Independent and interactive effects of plant sterols and fish oiln-3 long-chain polyunsaturated fatty acids on the plasma lipid profile of mildly hyperlipidaemic Indian adults
Authors: Khandelwal Shweta , Demonty Isabelle , Jeemon Panniyammakal , Lakshmy Ramakrishnan , Mukherjee Rajat , Gupta Ruby , Snehi Uma , Niveditha Devasenapathy , Singh Yogendra , van der Knaap Henk C. M. , Passi Santosh J. , Prabhakaran Dorairaj , Reddy K. Srinath
Published: March 2009

The present study was designed to evaluate the independent and interactive effects of a once-a-day yoghurt drink providing 2 g plant sterols/d and capsules providing 2 g fish oiln-3 long-chain (LC) PUFA/d on plasma lipids, apolipoproteins and LDL particle size. Following a 2-week run-in period, 200 mildly hypercholesterolaemic Indian adults aged 35–55 years were randomised into one of four groups of a 2 × 2 factorial, double-blind controlled trial. The 4-week treatments consisted of (1) control yoghurt drink and control capsules, (2) control yoghurt drink and fish oil capsules, (3) plant sterol-enriched yoghurt drink and control capsules, or (4) plant sterol-enriched yoghurt drink and fish oil capsules. Blood was drawn before and after the 4-week intervention. Changes in health status, lifestyle and dietary habits, and daily compliance were recorded. The main effects of plant sterols were a 4·5 % reduction in LDL-cholesterol and a 15 % reduction in TAG without a significant change in HDL-cholesterol. Overall, fish oiln-3 LC-PUFA did not significantly affect cholesterol concentrations but reduced TAG by 15 % and increased HDL-cholesterol by 5·4 %. The combination significantly lowered TAG by 15 %v.control. No significant interaction between plant sterols andn-3 LC-PUFA was observed on plasma cholesterol concentrations. In conclusion, once-a-day intake of 2 g plant sterols/d in a yoghurt drink, 2 g fish oiln-3 LC-PUFA/d in capsules, and their combination had beneficial effects on the lipid profile of mildly hypercholesterolaemic Indian adults. The potent hypotriacylglycerolaemic effect of plant sterols observed in the present study and this population warrants additional investigation.
Trans-10,cis-12-conjugated linoleic acid reduces the hepatic triacylglycerol content and the leptin mRNA level in adipose tissue in obese Zucker fa/fa rats
Authors: Gudbrandsen Oddrun A. , Rodríguez Enrique , Wergedahl Hege , Mørk Sverre , Reseland Janne E. , Skorve Jon , Palou Andreu , Berge Rolf K.
Published: March 2009

Conjugated linoleic acid (CLA) isomers have been reported to reduce body weight and beneficially affect glucose metabolism in animals, but the results are inconsistent and seem to depend on animal model and type of CLA isomer. In the present study, feeding male Zucker fa/fa rats diets supplemented with 1 %trans-10,cis-12-CLA for 10 d reduced the liver TAG content without improving the overall adiposity, and enhanced hepatic mitochondrial and peroxisomal β-oxidation. The increased carnitine palmitoyltransferase (CPT)-I activity and mRNA level as well as the increasedn-3:n-6 PUFA ratio in liver suggest thattrans-10,cis-12-CLA increased the hepatic β-oxidation by stimulation of PPARα. The reduced hepatic TAG content may be partly due to lower activity of stearoyl-CoA desaturase, as the ratios of 18 : 1n-9:18 : 0 and 16 : 1n-7:16 : 0 were reduced in liver.Trans-10,cis-12-CLA increased the CPT-I mRNA in retroperitoneal white adipose tissue (WAT), and increased uncoupling protein-2 mRNA in epididymal and inguinal WAT depots. Leptin mRNA level was decreased in all examined WAT depots, implying reduced insulin sensitivity. The resistin mRNA level was increased in all WAT depots, whereas adiponectin mRNA was reduced in inguinal and retroperitoneal WAT. The present results suggest that dietary supplementation withtrans-10,cis-12-CLA may increase the catabolism of lipids in liver and adipose tissue. Moreover, we provide new data suggesting thattrans-10,cis-12-CLA modulates the expression of resistin and adiponectin inversely in adipose tissue. Hence, the present results suggest thattrans-10,cis-12-CLA may have some beneficial effects on lipid metabolism and adiposity but possibly reduces insulin sensitivity.
Alveolar and cystic echinococcosis: towards novel chemotherapeutical treatment options
Authors: Hemphill A. , Müller J.
Published: March 2009

Echinococcus granulosusandEchinococcus multilocularisare cestode parasites, of which the metacestode (larval) stages cause the neglected diseases cystic echinococcosis (CE) and alveolar echinococcosis (AE), respectively. The benzimidazoles albendazole and mebendazole are presently used for the chemotherapeutical treatment, alone or prior to and after surgery. However, in AE these benzimidazoles do not appear to be parasiticidalin vivo. In addition, failures in drug treatments as well as the occurrence of side-effects have been reported, leading to discontinuation of treatment or to progressive disease. Therefore, new drugs are needed to cure AE and CE. Strategies that are currently employed in order to identify novel chemotherapeutical treatment options includein vitroandin vivotesting of broad-spectrum anti-infective drugs or drugs that interfere with unlimited proliferation of cancer cells. The fact that the genome ofE. multilocularishas recently been sequenced has opened other avenues, such as the selection of novel drugs that interfere with the parasite signalling machinery, and the application ofin silicoapproaches by employing theEchinococcusgenome information to search for suitable targets for compounds of known mode of action.
Efficiency of Stenger test in confirming profound, unilateral pseudohypacusis
Authors: Durmaz A , Karahatay S , Satar B , Birkent H , Hidir Y
Published: March 2009

Objective:

Conscious and deceptive exaggeration of hearing loss is termed pseudohypacusis. Even though the Stenger test has been used in the management of pseudohypacusis for almost a century, its sensitivity, specificity and predictive values for unilateral pseudohypacusis have not previously been reported, to our best knowledge. We investigated the efficiency of the Stenger test in detecting unilateral pseudohypacusis, accepting auditory brainstem response testing as the ‘gold standard’.

Materials and methods:

Candidates with questionable profound or total hearing loss were enrolled in the study. Pure tone audiometry, speech and tonal Stenger tests, and click test auditory brainstem response measurement were performed. Accepting auditory brainstem response testing as the gold standard, the sensitivity, specificity and predictive values of the Stenger test for unilateral, profound pseudohypacusis were assessed.

Results:

Two hundred military candidates were enrolled in the study. The sensitivity and specificity of the Stenger test in verifying unilateral, profound hearing loss were 99.4 and 70 per cent, respectively. The positive and negative predictive values of the test were 87.5 and 98.4 per cent, respectively.

Conclusion:

The Stenger test is widely used for the evaluation of unilateral or asymmetrical pseudohypacusis. In our opinion, it is a powerfully reliable test. More difficult cases require objective electrophysiological testing to verify functional hearing loss and to exclude specific diagnoses that may imitate pseudohypacusis.
Urban Politics in the State Arena
Authors: Burns Nancy , Evans Laura , Gamm Gerald , McConnaughy Corrine
Published: March 2009

We seek to explain how states govern big cities. Political scientists' accounts of urban politics either fail to treat the state systematically or place state hostility at the center of such an account. Accounts by historians, by contrast, offer tools political scientists can use to theorize urban politics in the state arena. We use those tools, and we find that cities can manage the legislative process. This power starts with bill introduction and carries through to the vote on the floor. This ability results from a central feature of American state politics: on bills about big cities, state legislators now and in the past find their primary voting cues in the unity of local delegations. The city delegation, then, has tremendous power to manage the state's involvement in city affairs. In many respects, ours is an account of a special kind of divided government, with two institutional arenas where urban government is carried out.
The Political Development of Job Discrimination Litigation, 1963–1976
Authors: Farhang Sean
Published: March 2009

In lobbying for the job discrimination provisions of the Civil Rights Act (CRA) of 1964, liberal civil rights advocates wanted an administrative job discrimination enforcement regime modeled on the National Labor Relations Board (NLRB), with no private lawsuits. Pivotal conservative Republicans, empowered by a divided Democratic Party and the filibuster in the Senate, defeated an administrative framework and provided instead for private lawsuits with incentives for enforcement, including attorney's fees for winning plaintiffs. They were motivated by native suspicion toward bureaucratic regulation of business in general, as well as fear that they would not be able to control an NLRB-style civil rights agency in the hands of their ideological adversaries. In the political environment of 1963–64, some meaningful enforcement provisions were necessary, and to conservative Republicans private litigation was preferable to public bureaucracy.

This choice had important self-reinforcing policy feedback effects. Civil rights advocates were initially optimistic about agency implementation and skeptical about the efficacy of private litigation to enforce Title VII, even with attorney's fees for winning plaintiffs. In the late 1960s and early 1970s, however, civil rights advocates observed an agency lacking the material resources and political will and commitment to carry out its mission. At the same time, they observed levels of private enforcement that far exceeded their expectations, as well as courts inclined toward broadly proplaintiff interpretations of Title VII. The CRA of 1964's attorney's fees provisions also had the effect of contributing funds to civil rights groups that prosecuted lawsuits and of conjuring into being a private, for-profit bar to litigate civil rights claims in general, and job discrimination claims in particular. These developments drove a transformation in the enforcement preferences of civil rights groups toward private litigation, weakening their historic support for administrative implementation. Working together with the burgeoning for-profit civil rights bar, they mobilized to expand the fee-shifting provisions of the CRA of 1964 across the entire field of civil rights, which they accomplished by successfully lobbying for enactment of the Civil Rights Attorney's Fees Awards Act of 1976. Thus was created the modern civil rights enforcement framework.
Transformative Bureaucracy: Reagan's Lawyers and the Dynamics of Political Investment
Authors: Teles Steven M.
Published: March 2009

Previous work in law and political development has emphasized the role that a “support structure” in civil society plays in translating electoral success into legal outcomes. In this paper, I claim that legal change can also work in the other direction—political appointees in government can use their power to assist their allies in civil society. Drawing on in-depth interviews and archival materials, I show how—especially under Attorney General Meese—the Reagan Department of Justice invested in the ideas (through its support of originalism), organizations (especially the Federalist Society), and personnel of the conservative legal movement and reorganized itself to give these longer-term objectives more importance in the department. These investments add up to a case of “transformative bureaucracy”: the use of bureaucratic power to transform the conditions of future political conflict.
Survey of the Magellanic Clouds at 4.8 and 8.64 GHz
Authors: Dickel John , Gruendl Robert A. , McIntyre Vincent , Amy Shaun , Milne Douglas
Published: March 2009

Detailed 4.8 and 8.64 GHz radio images of the entire Large and Small Magellanic Clouds with half-power beamwidths of 35″ at 4.8 GHz and 22″ at 8.64 GHz have been obtained using the Australia Telescope Compact Array. Full polarimetric observations were made. Several thousand mosaic positions were used to cover an area of 6° on a side for the LMC and 4.5° for the SMC. These images have sufficient spatial resolution (~ 8 and 5 pc, respectively) and sensitivity (3σ of 1.5 mJy beam−1) to identify most of the individual supernova remnants and H ii regions and also, in combination with available data from the Parkes 64-m telescope, the structure of the smooth emission in these galaxies. We have recently revised the early data analysis (Dickel et al. 2005) by increasing the CLEAN cutoff limit to recover more intermediate-spacing data and thus present more accurate brightnesses for extended sources. In addition, limited data using the sixth antenna at 4.5 – 6 km baselines are available to distinguish bright point sources (< 3″ and 2″, respectively) and to help estimate sizes of individual sources smaller than the resolution of the full survey. The resulting database will be valuable for statistical studies and comparisons with X-ray, optical, and infrared surveys of the LMC with similar resolution.
New distance and depth estimates from observations of eclipsing binaries in the SMC
Authors: North Pierre L. , Gauderon Romain , Royer Frédéric
Published: March 2009

A sample of 33 eclipsing binaries observed in a field of the SMC with FLAMES@VLT is presented. The radial velocity curves obtained, together with existing OGLE light curves, allowed the determination of all stellar and orbital parameters of these binary systems. The mean distance modulus of the observed part of the SMC is 19.05 mag, based on the 26 most reliable systems. Assuming an average error of 0.1 mag on the distance modulus to an individual system, and a gaussian distribution of the distance moduli, we obtain a 2-σ depth of 0.36 mag or 10.6 kpc. Some results on the kinematics of the binary stars and of the H ii gas are also given.
The disruption of the Magellanic Stream
Authors: Bland-Hawthorn J.
Published: March 2009

We present evidence that the accretion of warm gas onto the Galaxy today is at least as important as cold gas accretion. For more than a decade, the source of the bright Hα emission (up to 750 mR†) along the Magellanic Stream has remained a mystery. We present a hydrodynamical model that explains the known properties of the Hα emission and provides new insights on the lifetime of the Stream clouds. The upstream clouds are gradually disrupted due to their interaction with the hot halo gas. The clouds that follow plough into gas ablated from the upstream clouds, leading to shock ionisation at the leading edges of the downstream clouds. Since the following clouds also experience ablation, and weaker Hα (100–200 mR) is quite extensive, a disruptive cascade must be operating along much of the Stream. In order to light up much of the Stream as observed, it must have a small angle of attack (≈ 20°) to the halo, and this may already find support in new H i observations. Another prediction is that the Balmer ratio (Hα/Hβ) will be substantially enhanced due to the slow shock; this will soon be tested by upcoming WHAM observations in Chile. We find that the clouds are evolving on timescales of 100–200 Myr, such that the Stream must be replenished by the Magellanic Clouds at a fairly constant rate (≳ 0.1 M⊙ yr−1). The ablated material falls onto the Galaxy as a warm drizzle; diffuse ionized gas at 104 K is an important constituent of galactic accretion. The observed Hα emission provides a new constraint on the rate of disruption of the Stream and, consequently, the infall rate of metal-poor gas onto the Galaxy. When the ionized component of the infalling gas is accounted for, the rate of gas accretion is ≳ 0.4 M⊙ yr−1, roughly twice the rate deduced from H i observations alone.
Dust in the Magellanic Clouds
Authors: Boulanger François
Published: March 2009

The Magellanic Clouds are important templates for studying the role interstellar dust plays as actor and tracer of galaxy evolution. Due to their proximity, the Large and Small Magellanic clouds are uniquely suited to put detailed Galactic dust studies in a global context. With a metal abundance lower than that of the Sun, the Magellanic Clouds also permit to characterize interstellar matter composition and structure as a function of metallicity. The presentation of spectacular results from the AKARI and Spitzer surveys was one of the highlights of this Magellanic Clouds meeting. This paper puts these results in context. I discuss UV extinction and IR emission signatures of carbon and silicate dust. I present diverse evidence of dust processing in the ISM. I illustrate the correlation between the mm emission of dust, and gas column density using Milky Way surveys. I conclude with three main results. Dust in the SMC is not carbon poor. The composition of interstellar dust reflects its processing in interstellar space and thereby depends on local conditions and its past history. In the Magellanic Clouds, far-IR and sub-mm observations are indicating that there may be significantly more cold interstellar matter, cold H i and H2 gas, than estimated from H i and CO observations.
Early results from the SAGE-SMC Spitzer legacy
Authors: Gordon Karl D. , Meixner M. , Blum R. D. , Reach W. , Whitney B. A. , Harris J. , Indebetouw R. , Bolatto A. D. , Bernard J.-P. , Sewilo M. , Babler B. L. , Block M. , Bot C. , Bracker S. , Carlson L. , Churchwell E. , Clayton G. C. , Cohen M. , Engelbracht C. W. , Fukui Y. , Gorjian V. , Hony S. , Hora J. L. , Israel F. , Kawamura A. , Leroy A. K. , Li A. , Madden S. , Marble A. R. , Markwick-Kemper F. , Meade M. , Misselt K. A. , Mizuno A. , Mizuno N. , Muller E. , Oliveira J. M. , Olsen K. , Onishi T. , Paladini R. , Paradis D. , Points S. , Robitaille T. , Rubin D. , Sandstrom K. M. , Sato S. , Shibai H. , Simon J. D. , Smith L. J. , Srinivasan S. , Tielens A. G. G. M. , Vijh U. P. , van Dyk S. , van Loon J. Th. , Volk K. , Zaritsky D.
Published: March 2009

Early results from the SAGE-SMC (Surveying the Agents of Galaxy Evolution in the tidally-disrupted, low-metallicity Small Magellanic Cloud) Spitzer legacy program are presented. These early results concentrate on the SAGE-SMC MIPS observations of the SMC Tail region. This region is the high H i column density portion of the Magellanic Bridge adjacent to the SMC Wing. We detect infrared dust emission and measure the gas-to-dust ratio in the SMC Tail and find it similar to that of the SMC Body. In addition, we find two embedded cluster regions that are resolved into multiple sources at all MIPS wavelengths.
The sub-solar initial mass function in the Large Magellanic Cloud
Authors: Gouliermis Dimitrios A.
Published: March 2009

The Magellanic Clouds offer a unique variety of star forming regions seen as bright nebulae of ionized gas, related to bright young stellar associations. Nowadays, observations with the high resolving efficiency of the Hubble Space Telescope allow the detection of the faintest infant stars, and a more complete picture of clustered star formation in our dwarf neighbors has emerged. I present results from our studies of the Magellanic Clouds, with emphasis in the young low-mass pre-main sequence populations. Our data include imaging with the Advanced Camera for Surveys of the association LH 95 in the Large Magellanic Cloud, the deepest observations ever taken with HST of this galaxy. I discuss our findings in terms of the initial mass function, which we constructed with an unprecedented completeness down to the sub-solar regime, as the outcome of star formation in the low-metallicity environment of the LMC.
Breaking the age–metallicity degeneracy: The metallicity distribution and star formation history of the Large Magellanic Cloud
Authors: Cole Andrew A. , Grocholski Aaron J. , Geisler Doug , Sarajedini Ata , Smith Verne V. , Tolstoy Eline
Published: March 2009

We have obtained metallicities from near-infrared calcium triplet spectroscopy for nearly a thousand red giants in 28 fields spanning a range of radial distances from the center of the bar to near the tidal radius. We have used these data to investigate the radius-metallicity and age-metallicity relations. A powerful application of these data is in conjunction with the analysis of deep HST color–magnitude diagrams (CMDs). Most of the power in determining a robust star-formation history from a CMD comes from the main-sequence turnoff and subgiant branches. The age-metallicity degeneracy that results is largely broken by the red giant branch color, but theoretical model RGB colors remain uncertain. By incorporating the observed metallicity distribution function into the modelling process, a star-formation history with massively increased precision and accuracy can be derived. We incorporate the observed metallicity distribution of the LMC bar into a maximum-likelihood analysis of the bar CMD, and present a new star formation history and age–metallicity relation for the bar. The bar is certainly younger than the disk as a whole, and the most reliable estimates of its age are in the 5–6 Gyr range, when the mean gas abundance of the LMC had already increased to [Fe/H] ≳ −0.6. There is no obvious metallicity gradient among the old stars in the LMC disk out to a distance of 8–10 kpc, but the bar is more metal-rich than the disk by ≈0.1–0.2 dex. This is likely to be the result of the bar's younger average age. In both disk and bar, 95% of the red giants are more metal-rich than [Fe/H] = −1.2.
The WFI Hα spectroscopic survey of the Magellanic Clouds: Be stars in SMC open clusters
Authors: Martayan Christophe , Baade Dietrich , Fabregat Juan
Published: March 2009

At low metallicity, B-type stars show lower loss of mass and, therefore, angular momentum so that it is expected that there are more Be stars in the Magellanic Clouds than in the Milky Way. However, till now, searches for Be stars were only performed in a very small number of open clusters in the Magellanic Clouds. Using the ESO/WFI in its slitless spectroscopic mode, we performed a Hα survey of the Large and Small Magellanic Cloud. Eight million low-resolution spectra centered on Hα were obtained. For their automatic analysis, we developed the ALBUM code. Here, we present the observations, the method to exploit the data and first results for 84 open clusters in the SMC. In particular, cross-correlating our catalogs with OGLE positional and photometric data, we classified more than 4000 stars and were able to find the B and Be stars in them. We show the evolution of the rates of Be stars as functions of area density, metallicity, spectral type, and age.
The optically bright post-AGB population of the LMC
Authors: van Aarle Els , van Winckel Hans , Evans Tom Lloyd , Wood Peter R.
Published: March 2009

The detected variety in chemistry and circumstellar shell morphology of the limited sample of Galactic post-AGB stars is so large, that there is no consensus yet on how individual objects are linked by evolutionary channels. The evaluation is complicated by the fact that the distances and hence luminosities of these objects are poorly known. In this contribution we report on our project to overcome this problem by focusing on a significant sample of post-AGB stars with known distances: those in the LMC. Via cross-correlation of the infrared SAGE-SPITZER catalogue with optical catalogues we selected a sample of 322 LMC post-AGB candidates based on their position in the various colour-colour diagrams. We determined the fundamental properties of 82 of them, using low resolution optical spectra that we obtained at Siding Spring and SAAO. We selected a subsample to be studied at high spectral resolution in order to obtain accurate abundances of a wide range of species. This will allow us to connect the theoretical predictions with the obtained surface chemistry at a given luminosity and metallicity. By this, we want to constrain important structure parameters of the evolutionary models. Preliminary results of the selection process are presented.
The population of Magellanic Cloud planetary nebulae
Authors: Stanghellini Letizia
Published: March 2009

In this review we address the progress that has been made toward the understanding of Magellanic Cloud planetary nebulae (PNe) and their evolution since the last Magellanic Cloud Symposium. Planetary nebulae in the Magellanic Clouds are the key probes of stellar and circumstellar evolution, both for their known distances and relative vicinity, and for their broad metallicity range A selection of recent results is presented, including the HST study of PNe and their central stars, the study of the population of Magellanic Cloud PNe based on abundance analysis, the recent Spitzer analysis of their dust contents, and the use of Magellanic Cloud PNe to constrain the distance scale of Galactic PNe.
Evidence of Magellanic-like moderate redshift H i-rich galaxies
Authors: Lawton Brandon , Churchill Christopher W. , York Brian A. , Ellison Sara L. , Snow Theodore P. , Johnson Rachel A. , Ryan Sean G. , Benn Chris R.
Published: March 2009

We present equivalent width measurements and limits of six diffuse interstellar bands (DIBs, λ 4428, λ 5705, λ 5780, λ 5797, λ 6284, and λ 6613) in seven damped Lyα absorbers (DLAs) over the redshift range 0.091 ≤ z ≤ 0.524, sampling 20.3 ≤ log N(Hi) ≤ 21.7. Based upon the Galactic DIB–N(H i) relation, the λ 6284 DIB equivalent width upper limits in four of the seven DLAs are a factor of 4–10 times below the λ 6284 DIB equivalent widths observed in the Galaxy, but are not inconsistent with those present in the Magellanic Clouds. Assuming the Galactic DIB–E(B − V) relation, we determine reddening upper limits for the DLAs in our sample. Based upon the E(B − V) limits, the gas-to-dust ratios, N(H i)/E(B − V), of the four aforementioned DLAs are at least ~5 times higher than that of the Galactic ISM and are more consistent with the Large Magellanic Cloud. The ratios of two other DLAs are at least a factor of a few times higher. The best constraints on reddening derive from the upper limits for the λ 5780 and λ 6284 DIBs, which yield E(B − V) ≤ 0.08 mag for four of the seven DLAs and are more consistent with the Magellanic Clouds rather than the Galaxy. Our results suggest that, in DLAs, quantities related to dust, such as reddening and metallicity, appear to have a greater impact on DIB strengths than does H i gas abundance. The molecules responsible for the DIBs in DLA selected sightlines are underabundant relative to sightlines in the Galaxy of similarly high N(H i). Using DIBs to study the ISM of DLAs provide evidence that at least some population of DLAs are more Magellanic-like than Galactic-like.
Mitigation of wideband interference on UWB-IR transmission using multi-carrier templates
Authors: Lakshmanan Madan Kumar , Nikookar Homayoun
Published: March 2009

Ultra wideband (UWB) wireless systems are highly susceptible to interference from other services. To reduce the effect of interference from co-existing sources such as the WLAN standard IEEE 802.11a on UWB Communication, the construction of a modified template waveform using multi-carrier sinusoids is proposed in Ohno and Ikegami (2003), Ohno et al. (2004), Ohno and Ikegami (2006), and Lakshmanan and Nikookar (2007). However, the work in Ohno and Ikegami (2003), Ohno et al. (2004), Ohno and Ikegami (2006), and Lakshmanan and Nikookar (2007) considers a free space propagation channel model with no treatment of the frequency dependence of the path loss. In this paper, we broaden the study by taking into consideration a frequency-dependent path loss environment. The novelty of the work is in the investigation of the effect of frequency dependency of the path loss on the performance of interference mitigation schemes.
An eigencurrent description of finite arrays of electromagnetically characterized elements
Authors: Bekers D. J. , van Eijndhoven S. J. L. , Tijhuis A. G.
Published: March 2009

To describe the behavior of a finite array, the current distribution on each of its elements is represented by a finite number of eigencurrents or modes. Subsequently, the eigencurrents of the array are expanded in terms of these element eigencurrents. For uniform linear arrays of loops and dipoles, the array‐eigencurrent expansions and their associated eigenvalues are investigated. We focus on their parameter independent and diagonalizing features, and on their interpretation in terms of far‐field characteristics and (standing) wave behavior.
Analysis and improvements of cloud models for propagation studies
Authors: Mattioli V. , Basili P. , Bonafoni S. , Ciotti P. , Westwater E. R.
Published: March 2009

Two cloud models currently in use in propagation and remote sensing simulations in the presence of nonprecipitating clouds were analyzed. A new cloud model is also proposed: a modification of a humidity threshold to better identify clouds is suggested, as is a new cloud density function for computing cloud liquid and ice content within a cloud. The performances of the threshold functions were examined at the Atmospheric Radiation Measurement (ARM) Program's Southern Great Plaints (SGP) site in Oklahoma, USA, by using radiosonde and ceilometer data. The new threshold showed an improvement in the cloud detection (15%) and a reduction of false cloud identification in clear‐sky conditions (26%). Next, the cloud density models were evaluated in the brightness temperature (Tb) domain, by comparing simulated Tb values in cloudy conditions with those measured by dual‐channel microwave radiometers at several ARM sites. The new model provided good results in comparison with the radiometer measurements, with overall root mean square (RMS) differences of 3.10 K, reducing the RMS by about 16% with respect to the best of the other models. Improvements can be noticed in particular at SGP (20%), and in the tropics (37%).