bluuebunny/crossref_metadata_2025_split huggingface dataset:
Bivariate Non-Normality in the Sample Selection Model
Authors: Pigini Claudia 
Published: August 2014

Abstract
Since the seminal paper by [Heckman, J. J. 1974. “Shadow Prices, Market Wages, and Labor Supply.” Econometrica 42: 679–694], the sample selection model has been an essential tool for applied economists and arguably the most sensitive to sources of misspecification among the standard microeconometric models involving limited dependent variables. The need for alternative methods to get consistent estimators has led to a number of estimation proposals for the sample selection model under non-normality. There is a marked dichotomy in the literature that has developed in two conceptually different directions: the bivariate normality assumption can be either replaced, by using copulae, or relaxed/removed, relying on semi- and non-parametric estimators. This paper surveys the more recent proposals on the estimation of the sample selection model that deal with distributional misspecification giving the practitioner a unified framework of both parametric and semi/non-parametric options.
First trimester prediction of maternal glycemic status
Authors: Gabbay-Benziv Rinat , Doyle Lauren E. , Blitzer Miriam , Baschat Ahmet A. 
Published: August 2014

Abstract

Objective: To predict gestational diabetes mellitus (GDM) or normoglycemic status using first trimester maternal characteristics.

Methods: We used data from a prospective cohort study. First trimester maternal characteristics were compared between women with and without GDM. Association of these variables with sugar values at glucose challenge test (GCT) and subsequent GDM was tested to identify key parameters. A predictive algorithm for GDM was developed and receiver operating characteristics (ROC) statistics was used to derive the optimal risk score. We defined normoglycemic state, when GCT and all four sugar values at oral glucose tolerance test, whenever obtained, were normal. Using same statistical approach, we developed an algorithm to predict the normoglycemic state.

Results: Maternal age, race, prior GDM, first trimester BMI, and systolic blood pressure (SBP) were all significantly associated with GDM. Age, BMI, and SBP were also associated with GCT values. The logistic regression analysis constructed equation and the calculated risk score yielded sensitivity, specificity, positive predictive value, and negative predictive value of 85%, 62%, 13.8%, and 98.3% for a cut-off value of 0.042, respectively (ROC-AUC – area under the curve 0.819, CI – confidence interval 0.769–0.868). The model constructed for normoglycemia prediction demonstrated lower performance (ROC-AUC 0.707, CI 0.668–0.746).

Conclusions: GDM prediction can be achieved during the first trimester encounter by integration of maternal characteristics and basic measurements while normoglycemic status prediction is less effective.
Optimal control problems for linear backward doubly stochastic differential equations
Authors: Gherbal Boulakhras 
Published: August 2014

Abstract
In this paper we prove the existence of strict optimal controls for linear
backward doubly stochastic differential equations (LBDSDEs in short), where the control
domain and the cost function were assumed convex. The proof is based on strong
convergence techniques for the associated linear backward doubly stochastic
differential equations and Mazur's theorem. We derive also necessary and
sufficient conditions for optimality for this control problem. This result is
based on the convex optimization principle.
Taking control over intracellular fatty acid levels is essential for the analysis of thermogenic function in cultured primary brown and brite/beige adipocytes
Authors: Li Yongguo , Fromme Tobias , Schweizer Sabine , Schöttl Theresa , Klingenspor Martin 
Published: August 2014

AbstractThermogenesis in brown adipocytes, conferred by mitochondrial uncoupling protein 1 (UCP1), is receiving great attention because metabolically active brown adipose tissue may protect humans from metabolic diseases. In particular, the thermogenic function of brown‐like adipocytes in white adipose tissue, known as brite (or beige) adipocytes, is currently of prime interest. A valid procedure to quantify the specific contribution of UCP1 to thermogenesis is thus of vital importance. Adrenergic stimulation of lipolysis is a common way to activate UCP1. We here report, however, that in this frequently applied setup, taking control over intracellular fatty acid levels is essential for the analysis of thermogenic function in cultured brown and brite adipocytes. By the application of these findings, we demonstrate that UCP1 is functionally thermogenic in intact brite adipocytes and adrenergic UCP1 activation is largely dependent on adipose triglyceride lipase (ATGL) rather than hormone sensitive lipase (HSL).
Impact of a Pertussis Epidemic on Infant Vaccination in Washington State
Authors: Wolf Elizabeth R. , Opel Douglas , DeHart M. Patricia , Warren Jodi , Rowhani-Rahbar Ali 
Published: August 2014

BACKGROUND AND OBJECTIVES:
Washington State experienced a pertussis epidemic from October 2011 to December 2012. There was wide variation in incidence by county. The objectives of this study were to determine how the pertussis epidemic affected infant vaccination in Washington State and whether the incidence in counties modified this effect.

METHODS:
We conducted an ecologic before–after study to compare the proportion of infants up to date (UTD) with a pertussis-containing vaccine at time points before (September 30, 2011), during (September 30, 2012), and after (September 30, 2013) the epidemic. Children aged 3 to 8 months enrolled in the Washington State Immunization Information System with documented county of residence were included. UTD status was determined as ≥1, ≥2, or ≥3 doses of a pertussis-containing vaccine at ages 3, 5, and 7 months, respectively. Generalized linear models with extension to the binomial family and clustered robust standard errors were used to examine differences in the proportion of UTD infants between preepidemic and either epidemic or postepidemic points. The potential modifying effect of pertussis incidence by county was examined.

RESULTS:
We found no significant difference in statewide UTD status with a pertussis-containing vaccine between preepidemic and either epidemic (absolute difference 2.1%; 95% confidence interval, −1.6 to 5.9) or postepidemic (absolute difference 0.2%; 95% confidence interval, −4.0 to 4.5) time points. There was no significant modification by county pertussis incidence. There was wide variation in the absolute difference in UTD status across counties.

CONCLUSIONS:
A statewide pertussis epidemic does not appear to have significantly changed the proportion of infants who were UTD with a pertussis-containing vaccine.
High-dose Vitamin A With Vaccination After 6 Months of Age: A Randomized Trial
Authors: Fisker Ane B. , Bale Carlito , Rodrigues Amabelia , Balde Ibraima , Fernandes Manuel , Jørgensen Mathias J. , Danneskiold-Samsøe Niels , Hornshøj Linda , Rasmussen Julie , Christensen Emil D. , Bibby Bo M. , Aaby Peter , Benn Christine S. 
Published: August 2014

BACKGROUND:
The World Health Organization recommends vitamin A supplementation (VAS) at routine vaccination contacts after 6 months of age based on the assumption that it reduces mortality by 24%. The policy has never been evaluated in randomized controlled trials for its effect on overall mortality. We conducted a randomized double-blind trial to evaluate the effect of VAS with vaccines.

METHODS:
We randomized children aged 6 to 23 months 1:1 to VAS (100 000 IU if aged 6–11 months, 200 000 IU if aged 12–23 months) or placebo at vaccination contacts in Guinea-Bissau. Mortality rates were compared in Cox proportional-hazards models overall, and by gender and vaccine.

RESULTS:
Between August 2007 and November 2010, 7587 children were enrolled. Within 6 months of follow-up 80 nonaccident deaths occurred (VAS: 38; placebo: 42). The mortality rate ratio (MRR) comparing VAS versus placebo recipients was 0.91 (95% confidence interval 0.59–1.41) and differed significantly between boys (MRR 1.92 [0.98–3.75]) and girls (MRR 0.45 [0.24–0.87]) (P = .003 for interaction between VAS and gender). At enrollment, 42% (3161/7587) received live measles vaccine, 29% (2154/7587) received inactivated diphtheria-tetanus-pertussis–containing vaccines, and 21% (1610/7587) received both live and inactivated vaccines. The effect of VAS did not differ by vaccine group.

CONCLUSIONS:
This is the first randomized controlled trial to assess the effect of the policy on overall mortality. VAS had no overall effect, but the effect differed significantly by gender. More trials to ensure an optimal evidence-based vitamin A policy are warranted.
Neonatal Vitamin K Refusal and Nonimmunization
Authors: Sahni Vanita , Lai Florence Y. , MacDonald Shannon E. 
Published: August 2014

BACKGROUND:Neonatal Vitamin K prophylaxis is an effective intervention for reducing vitamin K deficiency bleeding. A recently published report of parental refusal of vitamin K prompted an investigation of the prevalence and characteristics of this group, and exploration of whether these same parents were likely to subsequently refuse immunization for their children.METHODS:We conducted a retrospective population-based cohort study of all infants born in Alberta between 2006 and 2012 by using linkage of administrative health data. Risk factors for vitamin K refusal were determined by using Poisson regression. The association between vitamin K refusal and nonimmunization was assessed using relative risk.RESULTS:Among the 282 378 children in the cohort, 99.7% received vitamin K and 0.3% declined. Midwife-assisted deliveries were more likely to be associated with vitamin K refusal compared with physician-attended delivery (risk ratio 8.4, 95% confidence interval [CI] 6.5–11.0). Planned home delivery (risk ratio 4.9, CI 3.8–6.4) or delivery in a birth center (risk ratio 3.6, CI 2.3–5.6) were more likely to result in decline of vitamin K compared with hospital delivery. Vitamin K refusal was associated with a 14.6 (CI 13.9–15.3) higher relative risk of having no recommended childhood vaccines at 15 months.CONCLUSIONS:This is the first population-based study to characterize parents who are likely to decline vitamin K for their infants and whose children are likely to be unimmunized. These findings enable earlier identification of high-risk parents and provide an opportunity to enact strategies to increase uptake of vitamin K and childhood immunizations.
College Graduation to Employment in STEM Careers: The Experience of New Graduates at the Intersection of Underrepresented Racial/Ethnic Minority Status and Disability
Authors: Hawley Carolyn E. , McMahon Brian T. , Cardoso Elizabeth D. , Fogg Neeta P. , Harrington Paul E. , Barbir Lara A. 
Published: August 2014

Purpose:To examine the recent labor market indicators of science, technology, engineering, and mathematics (STEM) versus non-STEM college graduates with disabilities.Method:The sample included bachelor of science (B.S.)/B.S.-level college graduates including 1,567,527 with a disability and 32,512,446 without a disability. Data were derived from the American Community Survey public use microdata files 2009–2011 inclusive. Three measures of labor market activity were used: labor force participation rate, unemployment ratio, and employment-to-population ratio.Results:Nonparametric tests of proportion with stringent alpha levels indicated that overall labor market participation was much lower for graduates with disabilities. Indicators improved somewhat for STEM graduates with disabilities perhaps because they persisted longer in their job search efforts. Within the sample of STEM graduates with disabilities, Whites experienced greater labor market participation than ethnic minorities. It was also found that supply-side interventions to improve STEM employment (i.e., government investment) have been markedly less effective than demand-side interventions (i.e., expanded recruitment of foreign STEM degree holders).Conclusion:Recent labor economics data and the expanded recruitment of foreign STEM degree holders bring into question whether or not a true STEM crisis exists today.
Experiences of Physical Activity One Year after Bariatric Surgery
Authors: Wiklund Malin , Olbers Monika Fagevik , Olbers Torsten , Willén Carin 
Published: August 2014

Background and purpose:
Obesity is a major global health problem today and the only evidence-based method
leading to a long-lasting weight reduction is bariatric surgery. Physical activity improves health, decreases the incidence
of several diseases and may influence weight loss outcome after bariatric surgery. Knowledge regarding how patients
experience physical activity after bariatric surgery could provide us with better tools to enhance physically active.

Methods:
The aim of the present study was to describe how patients experience physical activity one year after bariatric
surgery. An inductive qualitative content analysis was used to analyse semi-structured interviews with twenty-four
patients one year after bariatric surgery.

Results:
Results: The main findings emerged in four overarching themes: “Hindrances of physical activity”, “Physical activity with
a less obese body implies achievement”, “Coming to an understanding of the benefits of physical activity” and “Need of
support”.

Conclusion:
According to our findings patients experience both achievements and hinders with regard to physical activity
one year after surgery. Patients had an increased understanding of the benefits of physical activities, but support appears
necessary to obtain and maintain a suitable level.
Polymerization Shrinkage and Depth of Cure of Bulk-Fill Resin Composites and Highly Filled Flowable Resin
Authors: Jang J-H , Park S-H , Hwang I-N 
Published: August 2014

SUMMARY
The aim of this study was to evaluate the polymerization behavior and depth of cure (DOC) of recently introduced resin composites for posterior use: highly filled flowable composite and composites for bulk fill. A highly filled flowable (G-aenial Universal Flo [GUF]), two bulk-fill flowables (Surefil SDR Flow [SDR] and Venus Bulk fill [VBF]), and a bulk-fill nonflowable composite (Tetric N-Ceram Bulk fill [TBF]) were compared with two conventional composites (Tetric Flow [TF], Filtek Supreme Ultra [FS]). Linear polymerization shrinkage and polymerization shrinkage stress were each measured with custom-made devices. To evaluate DOC, the composite specimen was prepared using a mold with a hole of 4 mm depth and 4 mm internal diameter. The hole was bulk filled with each of the six composites and light cured for 20 seconds, followed by 24 hours of water storage. The surface hardness was measured on the top and the bottom using a Vickers microhardness (HV) indenter. The linear polymerization shrinkage of the composite specimens after photo-initiation decreased in the following order: TF and GUF &gt; VBF &gt; SDR &gt; FS and TBF (p&lt;0.05). The polymerization shrinkage stress of the six composite groups decreased in the following order: GUF &gt; TF and VBF &gt; SDR &gt; FS and TBF (p&lt;0.05). The mean bottom surface HV of SDR and VBF exceeded 80% of the top surface HV (HV-80%). However, the bottom of GUF and TBF failed to reach HV-80%. A highly filled flowable (GUF) revealed limitations in polymerization shrinkage and DOC. Bulk-fill flowables (SDR and VBF) were properly cured in 4-mm bulk, but they shrank more than the conventional nonflowable composite. A bulk-fill nonflowable (TBF) showed comparable shrinkage to the conventional nonflowable composite, but it was not sufficiently cured in the 4-mm bulk.
Color Masking of Developmental Enamel Defects: A Case Series
Authors: Torres CRG , Borges AB 
Published: August 2014

SUMMARY
Developmental defects involving color alteration of enamel frequently compromise the esthetic appearance of the tooth. The resin infiltration technique represents an alternative treatment for color masking of these lesions and uniformization of tooth color. This technique is considered relatively simple and microinvasive, since only a minimal portion of enamel is removed. This article illustrates the color-masking effect with resin infiltration of fluorosis and traumatic hypomineralization lesions with a case series. The final esthetic outcomes demonstrated the ability of the resin infiltrant to mask the color of white developmental defect lesions, resulting in satisfactory clinical esthetic improvements. However, in more severe cases, the color-masking effect was not complete.
Transdentinal Cell Photobiomodulation Using Different Wavelengths
Authors: Turrioni APS , Basso FG , Alonso JRL , de Oliveira CF , Hebling J , Bagnato VS , de Souza Costa CA 
Published: August 2014

SUMMARY

Objective
The aim of this study was to investigate the effects of transdentinal irradiation with different light-emitting diode (LED) parameters on odontoblast-like cells (MDPC-23).

Methods and Materials
Human dentin discs (0.2 mm thick) were obtained, and cells were seeded on their pulp surfaces with complete culture medium (Dulbecco modified Eagle medium). Discs were irradiated from the occlusal surfaces with LED at different wavelengths (450, 630, and 840 nm) and energy densities (0, 4, and 25 J/cm2). Cell viability (methyltetrazolium assay), alkaline phosphatase activity (ALP), total protein synthesis (TP), and cell morphology (scanning electron microscopy) were evaluated. Gene expression of collagen type I (Col-I) was analyzed by quantitative polymerase chain reaction (PCR). Data were analyzed by the Mann-Whitney test with a 5% significance level.

Results
Higher cell viability (21.8%) occurred when the cells were irradiated with 630 nm LED at 25 J/cm2. Concerning TP, no statistically significant difference was observed between irradiated and control groups. A significant increase in ALP activity was observed for all tested LED parameters, except for 450 nm at 4 J/cm2. Quantitative PCR showed a higher expression of Col-I by the cells subjected to infrared LED irradiation at 4 J/cm2. More attached cells were observed on dentin discs subjected to irradiation at 25 J/cm2 than at 4 J/cm2.

Conclusion
The infrared LED irradiation at an energy density of 4 J/cm2 and red LED at an energy density of 25 J/cm2 were the most effective parameters for transdentinal photobiomodulation of cultured odontoblast-like cells.
Effect of Hydrogen Peroxide Concentration on Enamel Color and Microhardness
Authors: Borges AB , Zanatta RF , Barros ACSM , Silva LC , Pucci CR , Torres CRG 
Published: August 2014

SUMMARY

Objectives
The aim of this study was to investigate the effect of hydrogen peroxide gels with different concentrations (20%, 25%, 30%, and 35%) on enamel Knoop microhardness (KNH) as well as on changes in dental color (C).

Methods
Cylindrical specimens of enamel/dentin (3-mm diameter and 2-mm thickness) were obtained from bovine incisors and randomly divided into six groups (n=20), according to the concentration of the whitening gel (20%, 25%, 30%, 35%, control, thickener). After polishing, initial values of KNH0 and color measurement, assessed by spectrophotometry using the CIE L*a*b* system, were taken from the enamel surface. The gels were applied on the enamel surface for 30 minutes, and immediate values of KNHi were taken. After seven days of being stored in artificial saliva, new measures of KNH7 and color (L7* a7* b7*, for calculating ΔE, ΔL, and Δb) were made. Data were submitted to statistical analysis of variance, followed by Tukey test (p&lt;0.05).

Results
Differences in gel concentration and time did not influence the microhardness (p=0.54 and p=0.29, respectively). In relation to color changes, ΔE data showed that the 35% gel presented a higher color alteration than the 20% gel did (p=0.006).

Conclusion
Bleaching with 35% hydrogen peroxide gel was more effective than with the 20% gel, without promoting significant adverse effects on enamel surface microhardness.
Children’s Book Illustrations: Visual Language of Picture Books
Authors: Hladíková Hana 
Published: August 2014

Abstract
High-quality picture books that merge text and illustration together in order to tell a story are eminent for healthy mental and social growth of children. This paper is to outline the benefits picture books bring to children between the ages three to eight, determine functions of its illustrative language, examine the process of its production, and point out a set of elements that, according to number of professional children's book illustrators, significantly contribute to the success of a picture book
Report on the Financial Evaluation: McDonald’s Corporation and Yum! Brands
Authors: Ayrapetova Tamara 
Published: August 2014

Abstract
The aim of this paper is to perform financial analysis by using financial ratios and to comment, evaluate, and understand the origins of the results by using the comparison of two companies chosen as a case study.
The McDonald's Corporation is the largest fast food restaurant in the world. McDonald's Corporation statistics base it in over 119 countries and it serves more than 68 million customers daily. The company's revenues are coming not only from its primary products like hamburgers, cheeseburgers, etc., but also from rent, royalties, and fees paid by the franchisees. This report will look at the financial statements of the McDonald's Corporation over the past 3 years starting from 2010 through 2012. The author of the paper will apply financial ratios to analyze company's position and to identify patterns and trends. She will then compare the results of the analysis with one of the biggest competitors of McDonald's - Yum! Brands Inc. and the industrial averages. Yum! Brands Inc. is a US based corporation. It includes famous brands like KFC and Pizza Hut in their chain. Currently Yum! Brands are the largest competitors McDonald's has in the fast-food industry. To compare the two companies financial statements will be taken from Yahoo Finance (2013).
Cervical intraspinal extradural primitive neuroectodermal tumour in an adult
Authors: Gogou Pinelopi V , Balafouta Myrsini J , Gennatas Constantinos S , Kondi-Paphiti Agatha , Papacharalampous Xenophon N. , Michalaki Vasiliki , Kouvaris John R 
Published: August 2014

Abstract
Intraspinal extradural primitive neuroectodermal tumours (PNET) represent a rare entity that almost always carry a poor prognosis. A recent literature research revealed only four cases reported in adults. The tumours have mainly thoracic and lumbar location. We report the only case with cervical location and with the longest survival. Urgent laminectomy was performed resulting in a rapid pain relief for the patient. The patient was followed up with craniospinal irradiation and several cycles of chemotherapy. The patient died due to dissemination of the disease 31 months after the diagnosis. Intraspinal PNET tumours have a rapidly progressive course, and there is no current consensus on the optimal therapeutic approach.
Double primary cancers registered in a tertiary care hospital: review of two cases
Authors: Mohammad Amrallah A. , Al-Zahrani Abdullah S. , El-Khatib Hani M. 
Published: August 2014

Abstract
In our centre, among 1965 registered cancer patients between May 2011 and December 2013, we report three cases with multiple primary malignant neoplasms. One of them was excluded due to lack of data, and so we present the remaining two cases. The first case is an 82-year-old female patient with colon and thyroid cancer and the second case is a 61-year-old female patient with colon and breast cancer. Both cases were metachronous and discovered accidently during the regular follow up, and managed with a curative intent. Conclusion: It is important for the clinicians to keep in mind that individuals with cancer are at increased risk for subsequent primary malignancies, which must be differentiated from recurrent or metastatic disease.