bluuebunny/crossref_metadata_2025_split huggingface dataset:
Relative clustering validity criteria: A comparative overview
Authors: Vendramin Lucas , Campello Ricardo J. G. B. , Hruschka Eduardo R. 
Published: July 2010

AbstractMany different relative clustering validity criteria exist that are very useful in practice as quantitative measures for evaluating the quality of data partitions, and new criteria have still been proposed from time to time. These criteria are endowed with particular features that may make each of them able to outperform others in specific classes of problems. In addition, they may have completely different computational requirements. Then, it is a hard task for the user to choose a specific criterion when he or she faces such a variety of possibilities. For this reason, a relevant issue within the field of clustering analysis consists of comparing the performances of existing validity criteria and, eventually, that of a new criterion to be proposed. In spite of this, the comparison paradigm traditionally adopted in the literature is subject to some conceptual limitations. The present paper describes an alternative, possibly complementary methodology for comparing clustering validity criteria and uses it to make an extensive comparison of the performances of 40 criteria over a collection of 962,928 partitions derived from five well‐known clustering algorithms and 1080 different data sets of a given class of interest. A detailed review of the relative criteria under investigation is also provided that includes an original comparative asymptotic analysis of their computational complexities. This work is intended to be a complement of the classic study reported in 1985 by Milligan and Cooper as well as a thorough extension of a preliminary paper by the authors themselves. Copyright © 2010 Wiley Periodicals, Inc. Statistical Analysis and Data Mining 3: 209‐235, 2010
Two Ta2O5‐Rich Alkali‐Metal Lanthanide(III) Oxotantalates(V): K2LaTa5O15 and NaTm2Ta15O41
Authors: Janka Oliver , Müller‐Bunz Helge , Schleid Thomas 
Published: July 2010

AbstractAlkali‐metal containing lanthanide oxotantalates(V) with high Ta2O5 content can be obtained using surfacially oxygen‐contaminated tantalum containers for acid‐base reactions with lanthanide oxides and alkali‐metal halides as fluxes. Following this way, the two title compounds K2LaTa5O15 and NaTm2Ta15O41 were prepared as colorless single crystals. K2LaTa5O15 crystallizes in the tetragonal space group P4/mbm (no. 127) with a = 1256.02(9), c = 392.14(3) pm and c/a = 0.312 (Z = 2), NaTm2Ta15O41 orthorhombically (space group: Pbam, no. 55) with a = 1261.43(7), b = 3080.3(2) and c = 386.05(2) pm (Z = 2). The quite similar a and c axes for both compounds suggest analogies in their structures and there are indeed common motifs within the oxotantalate(V) networks erected from corner‐sharing [TaO6]7– octahedra. Even more interesting is the fact that in NaTm2Ta15O41 an increased coordination number (CN = 7) for some Ta5+ cations can be found just like in the binary Ta2O5.
Choline and Ethanolamine Decompose Lipid Hydroperoxides into Hydroxyl Lipids
Authors: Pan Xiangqing , Irwin Anthony J. , Leonard Michael , Welsby David 
Published: July 2010

AbstractAnalysis of lipid hydroperoxides and hydroxyl lipids in food and biological systems has historically been difficult due to the instability and diversity of these compounds as well as the complexity of the associated purification and derivatization processes. A rapid, high throughput and robust method based on mass spectrometry using multiple reaction monitoring mode of LC–ESI–MS/MS has been developed for the simultaneous quantitative analysis of fatty acid hydroperoxides and hydroxyl fatty acids without purification or derivatization. The method has been used to demonstrate that functional groups of phospholipids, choline and ethanolamine, are capable of decomposing lipid hydroperoxides into their corresponding hydroxyl lipids. In model systems where choline and ethanolamine were added, the amounts of lipid hydroperoxide isomers decreased while the amounts of hydroxyl lipids increased. In similar model systems containing normal food antioxidants such as tocopherols and butylated hydroxytoluene, and in the control without antioxidants, the amounts of lipid hydroperoxide and hydroxyl lipids did not change significantly under current experimental conditions. Data also demonstrated that phospholipids have a much lower hydroperoxide decomposition ability than choline and ethanolamine, and that the antioxidant activity of phospholipids is probably due to the ability of choline, ethanolamine and other amines from phospholipid degradation to convert primary oxidation products to the corresponding hydroxyl lipids.
Dimensions of adolescent subjective social status within the school community: Description and correlates
Authors: Sweeting Helen , West Patrick , Young Robert , Kelly Shona 
Published: July 2010

ABSTRACTSchool pupils strive to meet both school‐defined and social goals, and the structure of adolescent self‐concept is multidimensional, including both academic and non‐academic self‐perceptions. However, subjective social status within the school community has been represented as a single dimension. Scottish 15‐year olds participating in a school‐based survey (N = 3194) rated their own status, compared to their school year‐group, via images of seven 10‐rung ladders. These generated a very high response rate, and factor analysis distinguished three dimensions: (1) ladders representing “popular”, “powerful”, “respected”, “attractive or stylish” and “trouble‐maker”; (2) “doing well at school” and “[not] a trouble‐maker”; and (3) “sporty”. Unique relationships with variables representing more objective and/or self‐report behavioural measures suggest these dimensions are markers of “peer”, “scholastic” and “sports” status. These analyses suggest multiple dimensions of adolescent social hierarchy can be very simply measured and contribute towards the development of more robust instruments within this area.
Delivery route preferences of urban women of low socioeconomic status
Authors: Kudish Bela , Mehta Shobha , Kruger Michael , Russell Evie , Sokol Robert J. 
Published: July 2010

AbstractObjectiveTo identify the main determinants of mode of delivery preference among urban dwelling women of lower socioeconomic status (SES).MethodsOver a 12‐month period, a self‐completion 36‐item questionnaire was administered to a convenience sample of 308 women within the first 3 postpartum days. Non‐parametric tests were used for analysis.ResultsStudy participants were mostly African American (> 85%), single mothers (> 75%), and unemployed (≥ 55%). Among the women, 85.7% had vaginal delivery (VD) and 14.3% had cesarean delivery (CD). Women who preferred CD (10%) were more likely to be concerned about a vaginal tear/episiotomy during VD, forceps, and a “big” baby compared with women who preferred VD, for whom “pushing the baby out myself” and “fear of cesarean” were the most important factors. In the final model of 7 factors, the 3 main factors found to positively impact maternal preference for CD were a vaginal cut during VD (P < 0.001), higher mean BMI (P = 0.001), and cesarean as the most recent delivery type (P < 0.001). The total explained variance by this model was 46%.ConclusionsShort‐term complications of a VD, higher BMI, and a previous cesarean delivery are the most significant factors that impact the preferences of women of lower SES for future mode of delivery.
Evaluation of laparoscopic management of gynecologic emergencies by residents
Authors: Minig Lucas , Velazco Andrea , Lamm Marina , Velez Jorge Iván , Venturini Nadia Caroppo , Testa Roberto 
Published: July 2010

AbstractObjectiveTo evaluate the feasibility of laparoscopic management of women with gynecologic emergencies by the residents and the chief resident in an organized resident training program.MethodsA retrospective study of patients with gynecologic emergencies who underwent laparoscopic surgery between January 1, 1999, and May 31, 2006 was done.ResultsFor the 369 patients included, the mean operative time of 74 ± 31.35 minutes was significantly increased by advanced patient age (P < 0.001), pelvic inflammatory disease with or without tubo‐ovarian abscess (PID ± TOA) (P < 0.050), the first semester of chief residency (P < 0.050), and conversion to laparotomy (P < 0.001). Mean length of hospital stay was 40 ± 24 hours. Factors such as advanced patient age (P < 0.001), prolonged length of surgery (P < 0.001), PID ± TOA (P < 0.001), first semester of chief residency (P < 0.050), conversion to laparotomy (P < 0.001), and blood transfusion (P < 0.050) significantly increased the length of hospital stay. The conversion rate to laparotomy was 4.6% (n = 17), and it was significantly associated with advanced women age (OR 1.11; 95% CI, 1.05–1.17, P < 0.001) and PID ± TOA (OR 6.04; 95%CI, 2.17–16.62, P < 0.001). Postoperative complications were recorded in 3 (0.81%) patients.ConclusionLaparoscopic management of gynecologic emergencies by senior residents and a chief resident within an organized resident training program is feasible. These results reinforce the relevance of a well‐structured residency endoscopic training program.
Acute supplementation with keto analogues and amino acids in rats during resistance exercise
Authors: de Almeida Rosemeire Dantas , Seixas Prado Eduardo , Daniel Llosa Carlos , Magalhães-Neto Anibal , Cameron Luiz-Claudio 
Published: July 2010

During exercise, ammonia levels are related to the appearance of both central and peripheral fatigue. Therefore, controlling the increase in ammonia levels is an important strategy in ameliorating the metabolic response to exercise and in improving athletic performance. Free amino acids can be used as substrates for ATP synthesis that produces ammonia as a side product. Keto analogues act in an opposite way, being used to synthesise amino acids whilst decreasing free ammonia in the blood. Adult male rats were divided into four groups based on receiving either keto analogues associated with amino acids (KAAA) or a placebo and resistance exercise or no exercise. There was an approximately 40 % increase in ammonaemia due to KAAA supplementation in resting animals. Exercise increased ammonia levels twofold with respect to the control, with a smaller increase (about 20 %) in ammonia levels due to exercise. Exercise itself causes a significant increase in blood urea levels (17 %). However, KAAA reduced blood urea levels to 75 % of the pre-exercise values. Blood urate levels increased 28 % in the KAAA group, independent of exercise. Supplementation increased glucose levels by 10 % compared with control animals. Exercise did not change glucose levels in either the control or supplemented groups. Exercise promoted a 57 % increase in lactate levels in the control group. Supplementation promoted a twofold exercise-induced increase in blood lactate levels. The present results suggest that an acute supplementation of KAAA can decrease hyperammonaemia induced by exercise.
Multiple Risky Assets, Transaction Costs, and Return Predictability: Allocation Rules and Implications for U.S. Investors
Authors: Lynch Anthony W. , Tan Sinan 
Published: July 2010

AbstractThis paper numerically solves the decision problem of a multiperiod constant relative risk aversion individual who faces transaction costs and has access to two risky assets, both with predictable returns. With proportional transaction costs and independent and identically distributed returns, we numerically find the rebalancing rule to be a no-trade region for the portfolio weights with rebalancing to the boundary. The shape of the no-trade region depends on the correlation between the two risky assets. With predictable returns, there is instead a no-trade region for each state. We also examine several important economic questions, including the utility cost of not being able to buy on margin or short stock.
Longer-Term Time-Series Volatility Forecasts
Authors: Ederington Louis H. , Guan Wei 
Published: July 2010

AbstractOption pricing models and longer-term value-at-risk (VaR) models generally require volatility forecasts over horizons considerably longer than the data frequency. The typical recursive procedure for generating longer-term forecasts keeps therelativeweights of recent and older observations the same for all forecast horizons. In contrast, we find that older observations are relatively more important in forecasting at longer horizons. We find that the Ederington and Guan (2005) model and a modified EGARCH (exponential generalized autoregressive conditional heteroskedastic) model in which parameter values vary with the forecast horizon forecast better out-of-sample than the GARCH (generalized autoregressive conditional heteroskedastic), EGARCH, and Glosten, Jagannathan, and Runkle (GJR) models across a wide variety of markets and forecast horizons.
Drift instabilities' interaction: A tightening of the B-direction component on the amplitude of the azimouthally propagating wave
Authors: XAPLANTERIS CONSTANTINE L. 
Published: July 2010

AbstractA suitable modification on the plasma production device makes the plasma column length changeable; the axially propagating wave strikes on the movable circular base of the cavity and the reflected wave is affected enough. A tightening on the azimouthally propagating wave makes the amplitude measurements precarious, and the previous experimental results for fixed cavity length are valid. A strong boundaries' influence on the instability's reinforcement makes clear the need to extend even more the thermonuclear reactor's dimensions. In the present paper, an extended research of plasma parameters has been carried out, a corresponding theoretical model is developed to explain the phenomena and the comparison to the simulated results has been confirmed.
Epidemiology and outcome of Gram-negative bloodstream infection in children: a population-based study
Authors: AL-HASAN M. N. , HUSKINS W. C. , LAHR B. D. , ECKEL-PASSOW J. E. , BADDOUR L. M. 
Published: July 2010

SUMMARYPopulation-based studies of Gram-negative bloodstream infection (BSI) in children are lacking. Therefore, we performed this population-based investigation in Olmsted County, Minnesota, to determine the incidence rate, site of acquisition, and outcome of Gram-negative BSI in children aged ⩽18 years. We used Kaplan–Meier method and Cox proportional hazard regression for mortality analysis. We identified 56 unique children with Gram-negative BSI during the past decade. The gender-adjusted incidence rate of Gram-negative BSI per 100 000 person-years was 129·7 [95% confidence interval (CI) 77·8–181·6]) in infants, with a sharp decline to 14·6 (95% CI 6·0–23·2) and 7·6 (95% CI 4·3–10·9) in children aged 1–4 and 5–18 years, respectively. The urinary tract was the most commonly identified source of infection (34%) and Escherichia coli was the most common pathogen isolated (38%). Over two-thirds (68%) of children had underlying medical conditions that predisposed to Gram-negative BSI. The overall 28-day and 1-year all-cause mortality rates were 11% (95% CI 3–18) and 18% (95% CI 8–28), respectively. Younger age and number of underlying medical conditions were associated with 28-day and 1-year mortality, respectively. Nosocomial or healthcare-associated acquisition was associated with both 28-day and 1-year mortality.
Novel Electron Tomographic Methods to Study the Morphology of Keratin Filament Networks
Authors: Sailer Michaela , Höhn Katharina , Lück Sebastian , Schmidt Volker , Beil Michael , Walther Paul 
Published: July 2010

AbstractThe three-dimensional (3D) keratin filament network of pancreatic carcinoma cells was investigated with different electron microscopical approaches. Semithin sections of high-pressure frozen and freeze substituted cells were analyzed with scanning transmission electron microscope (STEM) tomography. Preservation of subcellular structures was excellent, and keratin filaments could be observed; however, it was impossible to three-dimensionally track the individual filaments. To obtain a better signal-to-noise ratio in transmission mode, we observed ultrathin sections of high-pressure frozen and freeze substituted samples with low-voltage (30 kV) STEM. Contrast was improved compared to 300 kV, and individual filaments could be observed. The filament network of samples prepared by detergent extraction was imaged by high-resolution scanning electron microscopy (SEM) with very good signal-to-noise ratio using the secondary electron signal and the 3D structure could be elucidated by SEM tomography. In freeze-dried samples it was possible to discern between keratin filaments and actin filaments because the helical arrangement of actin subunits in the F-actin could be resolved. When comparing the network structures of the differently prepared samples, we found no obvious differences in filament length and branching, indicating that the intermediate filament network is less susceptible to preparation artifacts than the actin network.
Sub-Ångstrom Low-Voltage Performance of a Monochromated, Aberration-Corrected Transmission Electron Microscope
Authors: Bell David C. , Russo Christopher J. , Benner Gerd 
Published: July 2010

AbstractLowering the electron energy in the transmission electron microscope allows for a significant improvement in contrast of light elements and reduces knock-on damage for most materials. If low-voltage electron microscopes are defined as those with accelerating voltages below 100 kV, the introduction of aberration correctors and monochromators to the electron microscope column enables Ångstrom-level resolution, which was previously reserved for higher voltage instruments. Decreasing electron energy has three important advantages: (1) knock-on damage is lower, which is critically important for sensitive materials such as graphene and carbon nanotubes; (2) cross sections for electron-energy-loss spectroscopy increase, improving signal-to-noise for chemical analysis; (3) elastic scattering cross sections increase, improving contrast in high-resolution, zero-loss images. The results presented indicate that decreasing the acceleration voltage from 200 kV to 80 kV in a monochromated, aberration-corrected microscope enhances the contrast while retaining sub-Ångstrom resolution. These improvements in low-voltage performance are expected to produce many new results and enable a wealth of new experiments in materials science.
Dissent on Japan's Northern Periphery: Nemuro, the Northern Territories and the Limits of Change in a ‘Bureaucrat's Movement’
Authors: WILLIAMS BRAD 
Published: July 2010

AbstractThis article sheds light on a relatively unexplored aspect of the Northern Territories dispute by examining the views of residents in Nemuro – the symbolic frontline in Japan's Northern Territories Reversion Movement (NTRM). The NTRM began in this northern periphery as a movement of divergent attitudes but was soon coopted by the Japanese government for political reasons. Local opposition to the government's four island en bloc policy existed in some quarters but was largely kept in check by state largesse. However, as a result of demographic and socioeconomic changes, dissent is slowly emerging in Nemuro. There are signs of an emerging disjuncture between national policy and local aspirations. This disjuncture has both theoretical and policy implications. Theoretically, this paper is congruent with politico-institutional arguments emphasizing the impact of the regulatory regime in shaping civil society organizations. From a policy perspective, public opinion in Nemuro indicates a potential avenue for compromise in Tokyo's negotiating strategy, although pressure for change is unlikely to emerge from the bureaucratized NTRM.
Facilitating Vocabulary Acquisition of Young English Language Learners
Authors: Lugo-Neris Mirza J. , Jackson Carla Wood , Goldstein Howard 
Published: July 2010

Purpose
This study examined whether English-only vocabulary instruction or English vocabulary instruction enhanced with Spanish bridging produced greater word learning in young Spanish-speaking children learning English during a storybook reading intervention while considering individual language characteristics.

Method
Twenty-two Spanish-speaking children learning English (ages 4–6) who participated in a summer education program for migrant families were randomly assigned to receive 2 weeks of each instruction: (a) word expansions in English or (b) English readings with word expansions in Spanish. Researcher-created measures of target vocabulary were administered, as were English and Spanish standardized measures of language proficiency and vocabulary.

Results
Results revealed significant improvement in naming, receptive knowledge, and expressive definitions for those children who received Spanish bridging. Spanish expansions produced the greatest gains in the children’s use of expressive definitions. Initial language proficiency in both languages was found to affect participants' gains from intervention, as those with limited skills in both languages showed significantly less vocabulary growth than those with strong skills in Spanish.

Conclusions
Additional benefits to using Spanish expansions in vocabulary instruction were observed. Future research should explore additional ways of enhancing the vocabulary growth of children with limited skills in both languages in order to support and strengthen the child’s first language and promote second language acquisition.
The Relationship Between Different Measures of Oral Reading Fluency and Reading Comprehension in Second-Grade Students Who Evidence Different Oral Reading Fluency Difficulties
Authors: Wise Justin C. , Sevcik Rose A. , Morris Robin D. , Lovett Maureen W. , Wolf Maryanne , Kuhn Melanie , Meisinger Beth , Schwanenflugel Paula 
Published: July 2010

PurposeThe purpose of this study was to examine whether different measures of oral reading fluency relate differentially to reading comprehension performance in two samples of second-grade students: (a) students who evidenced difficulties with nonsense-word oral reading fluency, real-word oral reading fluency, and oral reading fluency of connected text (ORFD), and (b) students who evidenced difficulties only with oral reading fluency of connected text (CTD).MethodParticipants (ORFD,n= 146 and CTD,n= 949) were second-grade students who were recruited for participation in different reading intervention studies. Data analyzed were from measures of nonsense-word oral reading fluency, real-word oral reading fluency, oral reading fluency of connected text, and reading comprehension that were collected at the pre-intervention time point.ResultsCorrelational and path analyses indicated that real-word oral reading fluency was the strongest predictor of reading comprehension performance in both samples and across average and poor reading comprehension abilities.ConclusionResults of this study indicate that real-word oral reading fluency was the strongest predictor of reading comprehension and suggest that real-word oral reading fluency may be an efficient method for identifying potential reading comprehension difficulties.