bluuebunny/crossref_metadata_2025_split huggingface dataset:
A look at the value creation effects of patenting and capital investment through a real options lens: the moderating role of uncertainty
Authors: Levitas Edward , Chi Tailan 
Published: September 2010

AbstractThis article applies a real options approach to analyzing the impact of a firm's investment in appropriable technology (as represented by the intensity of its patenting activities and capital investment) on the firm's opportunities to create value through future investment (as represented by Tobin's q). Recognizing the mixed results with regard to the relationship between patenting and firm value, we argue that such investment may primarily create value by offering future technology options and that the relationship may be more appropriately modeled on the basis of real options theory. We argue that patenting creates and replenishes a firm's technology options whereas capital investment entails the exercise of such options. Three hypotheses are derived from a valuation model based on the real options approach and tested using a fixed‐effects panel data procedure. The results of our empirical analysis using a sample of 161 U.S.‐based biotechnology firms are consistent with our predictions. Copyright © 2010 Strategic Management Society.
Bias and efficiency of multiple imputation compared with complete‐case analysis for missing covariate values
Authors: White Ian R. , Carlin John B. 
Published: September 2010

AbstractWhen missing data occur in one or more covariates in a regression model, multiple imputation (MI) is widely advocated as an improvement over complete‐case analysis (CC). We use theoretical arguments and simulation studies to compare these methods with MI implemented under a missing at random assumption.When data are missing completely at random, both methods have negligible bias, and MI is more efficient than CC across a wide range of scenarios. For other missing data mechanisms, bias arises in one or both methods. In our simulation setting, CC is biased towards the null when data are missing at random. However, when missingness is independent of the outcome given the covariates, CC has negligible bias and MI is biased away from the null. With more general missing data mechanisms, bias tends to be smaller for MI than for CC.Since MI is not always better than CC for missing covariate problems, the choice of method should take into account what is known about the missing data mechanism in a particular substantive application. Importantly, the choice of method should not be based on comparison of standard errors. We propose new ways to understand empirical differences between MI and CC, which may provide insights into the appropriateness of the assumptions underlying each method, and we propose a new index for assessing the likely gain in precision from MI: the fraction of incomplete cases among the observed values of a covariate (FICO). Copyright © 2010 John Wiley & Sons, Ltd.
Bayesian approach to cancer‐trend analysis using age‐stratified Poisson regression models
Authors: Ghosh Pulak , Ghosh Kaushik , Tiwari Ram C. 
Published: September 2010

AbstractAnnual Percentage Change (APC) summarizes trends in age‐adjusted cancer rates over short time‐intervals. This measure implicitly assumes linearity of the log‐rates over the intervals in question, which may not be valid, especially for relatively longer time‐intervals. An alternative is the Average Annual Percentage Change (AAPC), which computes a weighted average of APC values over intervals where log‐rates are piece‐wise linear.In this article, we propose a Bayesian approach to calculating APC and AAPC values from age‐adjusted cancer rate data. The procedure involves modeling the corresponding counts using age‐specific Poisson regression models with a log‐link function that contains unknown joinpoints. The slope‐changes at the joinpoints are assumed to have a mixture distribution with point mass at zero and the joinpoints are assumed to be uniformly distributed subject to order‐restrictions. Additionally, the age‐specific intercept parameters are modeled nonparametrically using a Dirichlet process prior. The proposed method can be used to construct Bayesian credible intervals for AAPC using age‐adjusted mortality rates. This provides a significant improvement over the currently available frequentist method, where variance calculations are done conditional on the joinpoint locations.Simulation studies are used to demonstrate the success of the method in capturing trend‐changes. Finally, the proposed method is illustrated using data on prostate cancer incidence. Copyright © 2010 John Wiley & Sons, Ltd.
Viral Coat Proteins as Flexible Nano‐Building‐Blocks for Nanoparticle Encapsulation
Authors: Li Feng , Li Ke , Cui Zong‐Qiang , Zhang Zhi‐Ping , Wei Hong‐Ping , Gao Ding , Deng Jiao‐Yu , Zhang Xian‐En 
Published: September 2010

AbstractViral capsid–nanoparticle hybrid structures offer new opportunities for nanobiotechnology. We previously generated virus‐based nanoparticles (VNPs) of simian virus 40 (SV40) containing quantum dots (QDs) for cellular imaging. However, as an interesting issue of nano‐bio interfaces, the mechanism of nanoparticle (NP) encapsulation by viral coat proteins remains unclear. Here, four kinds of QDs with the same core/shell but different surface coatings are tested for encapsulation. All the QDs can be encapsulated efficiently and there is no correlation between the encapsulation efficiency and the surface charge of the QDs. All the SV40 VNPs encapsulating differently modified QDs show similar structures, fluorescence properties, and activity in entering living cells. These results demonstrate the flexibility of SV40 major capsid protein VP1 in NP encapsulation and provide new clues to the mechanism of NP packaging by viral shells.
Associations between diurnal preference, sleep quality and externalizing behaviours: a behavioural genetic analysis
Authors: Barclay N. L. , Eley T. C. , Maughan B. , Rowe R. , Gregory A. M. 
Published: September 2010

BackgroundCertain aspects of sleep co-occur with externalizing behaviours in youth, yet little is known about these associations in adults. The present study: (1) examines the associations between diurnal preference (morningness versus eveningness), sleep quality and externalizing behaviours; (2) explores the extent to which genetic and environmental influences are shared between or are unique to these phenotypes; (3) examines the extent to which genetic and environmental influences account for these associations.MethodQuestionnaires assessing diurnal preference, sleep quality and externalizing behaviours were completed by 1556 young adult twins and siblings.ResultsA preference for eveningness and poor sleep quality were associated with greater externalizing symptoms [r=0.28 (95% CI 0.23–0.33) and 0.34 (95% CI 0.28–0.39), respectively]. A total of 18% of the genetic influences on externalizing behaviours were shared with diurnal preference and sleep quality and an additional 14% were shared with sleep quality alone. Non-shared environmental influences common to the phenotypes were small (2%). The association between diurnal preference and externalizing behaviours was mostly explained by genetic influences [additive genetic influence (A)=80% (95% CI 0.56–1.01)], as was the association between sleep quality and externalizing behaviours [A=81% (95% CI 0.62–0.99)]. Non-shared environmental (E) influences accounted for the remaining variance for both associations [E=20% (95% CI −0.01 to 0.44) and 19% (95% CI 0.01–0.38), respectively].ConclusionsA preference for eveningness and poor sleep quality are moderately associated with externalizing behaviours in young adults. There is a moderate amount of shared genetic influences between the phenotypes and genetic influences account for a large proportion of the association between sleep and externalizing behaviours. Further research could focus on identifying specific genetic polymorphisms common to both sleep and externalizing behaviours.
Booms and Busts: the Burstiness of Star Formation in Nearby Dwarf Galaxies
Authors: Cole A. A. 
Published: September 2010

AbstractIn this review I summarise recent advances in our understanding of the importance of starburst events to the evolutionary histories of nearby galaxies. Ongoing bursts are easily diagnosed in emission-line surveys, but assessing the timing and intensity of fossil bursts requires more effort, usually demanding color–magnitude diagrams or spectroscopy of individual stars. For ages older than ∼1 Gyr, this type of observation is currently limited to the Local Group and its immediate surroundings. However, if the Local Volume is representative of the Universe as a whole, then studies of the age and metallicity distributions of star clusters and resolved stellar populations should give statistical clues as to the frequency and importance of bursts to the histories of galaxies in general. Based on starburst statistics in the literature and synthetic colour-magnitude diagram studies of Local Group galaxies, I attempt to distinguish between systemic starbursts that strongly impact galaxy evolution and stochastic bursts that can appear impressive but are ultimately of little significance on gigayear timescales. As a specific case, it appears as though IC 10, the only starburst galaxy in the Local Group, falls into the latter category and is not fundamentally different from other nearby dwarf irregular galaxies.
The novel biomarker growth differentiation factor 15 in heart failure with normal ejection fraction
Authors: Stahrenberg Raoul , Edelmann Frank , Mende Meinhard , Kockskämper Anke , Düngen Hans‐Dirk , Lüers Claus , Binder Lutz , Herrmann‐Lingen Christoph , Gelbrich Götz , Hasenfuß Gerd , Pieske Burkert , Wachter Rolf 
Published: September 2010

AimsHeart failure with normal ejection fraction (HFnEF) is an important clinical entity that remains incompletely understood. The novel biomarker growth differentiation factor 15 (GDF‐15) is elevated in systolic heart failure (HFrEF) and is predictive of an adverse outcome. We investigated the clinical relevance of GDF‐15 plasma levels in HFnEF.Methods and resultsA subgroup of patients from the ongoing DIAST‐CHF observational trial, with a history of chronic heart failure (CHF) or positive Framingham criteria at presentation, was selected. Patients were classified as having either HFrEF (n = 86) or HFnEF (n = 142) and compared with healthy elderly controls (n = 188) from the same cohort. Growth differentiation factor 15 levels in HFnEF were significantly higher than in controls and similar to those in HFrEF. In multivariate analysis, factors significantly associated with GDF‐15 levels were age, sex, estimated glomerular filtration rate (eGFR), presence of HFrEF and HFnEF. Growth differentiation factor 15 correlated with multiple echocardiographic markers of diastolic function and was associated with 6 min walk test performance and SF‐36 physical score on multivariate analysis in all patients. When using a classification for HFnEF that did not employ N‐terminal pro brain natriuretic peptide (NT‐proBNP) as a diagnostic criterion, the diagnostic properties of GDF‐15 for detecting HFnEF tended to be superior to those of NT‐proBNP, and a combination significantly improved diagnostic accuracy.ConclusionGrowth differentiation factor 15 is elevated in HFnEF to a similar degree as in HFrEF. It is independently associated with impairment in exercise capacity and in physical components of quality of life. Diagnostic precision of GDF‐15 is at least as good as that of NT‐proBNP and combining both markers improves diagnostic accuracy.
THE GROWTH AND NUTRITION OF THE AFRICAN ELEPHANT
Authors: McCullagh K. 
Published: September 2010

SUMMARYIn order to gain information on the growth and nutrition of two populations of elephants in Murchison Falls National Park, Uganda, their urinary excretions of hydroxyproline peptides (HP) were compared.Animals from the “south bank” population had a consistently higher level of excretion than corresponding animals from the “north bank” population. This indicated a faster rate of growth and a superior nutritional status in “south bank” animals at the time of sampling.The HP output from both populations was found to run parallel to the seasonal variation in rainfall and vegetation growth. Sampling from each population was carried out at a different time of the year and evidence is presented to show that the differences in the rate of growth are a direct result of this. It is concluded that any primary differences between the populations are small enough to be obliterated by seasonal changes.The effect of the seasons on the growth of the elephant is therefore examined in more detail, and a direct influence on collagen metabolism is discussed.
UTILIZATION OF THE HABITAT BY BUFFALO IN LAKE MANYARA NATIONAL PARK
Authors: Vesey‐FitzGerald Desmond Foster 
Published: September 2010

SUMMARYA study of habitat utilization by buffalo, the dominant grazing species, in Lake Manyara National Park was made against a background description of the vegetation. An account of the various grasslands, including phenological information, has been married to utilization data and rainfall records. The pastures and other furnishings of the environment are shown to be adequate for the animals occurring there, but the area is subject to climatic hazards and great variation in the lake level.Grazing results in the development of a mosaic of long and short grasses, and the significance of this as a means of assessing utilization is explained. It is shown that the quality of different growth stages and species of grasses, optimum utilization versus overgrazing, and the manner in which the pasture can be maintained in full production by being grazed, can be understood by examining the grazing‐induced mosaic.The method for monitoring the use of the different pastures is based on the measurement of leaf‐table height in grazing‐exclusion frames during periods of occupation, compared with that of the grazed grass outside the frames. The data obtained can be plotted as graphs and illustrated diagrammatically as a grazing calendar. This enables some constructive suggestions to be made concerning Park management.
A survey of intensive care unit visiting policies in the United Kingdom
Authors: Hunter J. D. , Goddard C. , Rothwell M. , Ketharaju S. , Cooper H. 
Published: September 2010

SummaryAdmission to an intensive care unit is a highly stressful event for both patients and their relatives. Feelings of anxiety, pain, fear and a sense of isolation are often reported by survivors of a critical illness, whilst the majority of relatives report symptoms of anxiety or depression while their relative was in the intensive care unit. Traditionally, infection control concerns and a belief that liberal visiting by patients’ relatives interferes with the provision of patient care have led many units to impose restricted visiting policies. However, recent studies suggest that an open visiting policy with unrestricted visiting hours improve visitors’ satisfaction and reduces anxiety. In order to determine current visiting practice and provision for relatives within intensive care units, a questionnaire was sent to the principal nurse in all units within the United Kingdom. A total of 206 hospitals out of 271 completed the survey (76%). We found that 165 (80.1%) of responding units still impose restricted visiting policies, with wide variations in the facilities available to patients’ relatives.
Comparative evaluation of atracurium dosed on ideal body weight vs. total body weight in morbidly obese patients
Authors: Van Kralingen Simone , Van De Garde Ewoudt M. W. , Knibbe Catherijne A. J. , Diepstraten Jeroen , Wiezer Marinus J. , Van Ramshorst Bert , Van Dongen Eric P. A. 
Published: September 2010

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT • Different conflicting reports have been published for the use of atracurium in morbidly obese patients. Dosing of atracurium based on lean body mass, total body weight, and total body weight with a dose reduction for every 10 kg more than 70 kg have been proposed. WHAT THIS STUDY ADDS • The current prospective randomized double‐blind study compares atracurium 0.5 mg kg−1 ideal body weight vs. 0.5 mg kg−1 total body weight when used as a muscle relaxant in morbidly obese patients undergoing bariatric surgery. Based on our results in patients with body weights varying from 112 to 260 kg, we have concluded that atracurium 0.5 mg kg−1 ideal body weight results in a predictable profile of muscle relaxation allowing for adequate intubation conditions and recovery of muscle strength within 60 min with lack of need for antagonism. A dose‐dependent prolongation of action is shown when dosing is based on total body weight.AIMS This double‐blind randomized study evaluated atracurium dosing based on ideal body weight vs. total body weight for muscle relaxation in morbidly obese patients undergoing bariatric surgery.METHODS Twenty patients (body weight 112–260 kg, BMI 38–79 kg m−2) were randomized to receive atracurium 0.5 mg kg−1 ideal body weight vs. 0.5 mg kg−1 total body weight. Primary endpoint was neuromuscular blockade using train‐of‐four ratios (TOF ratios) and secondary endpoints were intubation conditions and need for antagonism with neostigmine.RESULTS In the ideal body weight group, times to recovery of TOF ratio from 0 to 5%, 50% and 75% were significantly shorter [TOF ratio from 0 to 5%: mean difference 30 min (95% CI 23, 39 min)] and with lower variability compared with the total body weight group. In the total body weight group there was a significant correlation between atracurium dose and time to a TOF ratio of 5% (r= 0.82, P < 0.001), which was absent in the ideal body weight group (r= 0.24). In both groups, intubation conditions were good while 70% of the patients in the total body weight group needed neostigmine at the end of surgery compared with 0% in the ideal body weight group.CONCLUSION In morbid obesity (112–260 kg), atracurium 0.5 mg kg−1 ideal body weight results in a predictable profile of muscle relaxation allowing for adequate intubation conditions and recovery of muscle strength to a TOF ratio >90% within 60 min with lack of need for antagonism. A dose‐dependent prolongation of action is shown when dosing is based on total body weight.
The EULEV cohort study: rates of and factors associated with continuation of levetiracetam after 1 year
Authors: Droz‐Perroteau Cécile , Dureau‐Pournin Caroline , Vespignani Hervé , Marchal Cécile , Blin Patrick , Blazejewski Sylvie , Pollet Clothilde , Jové Jérémy , Robinson Philip , Moore Nicholas , Fourrier‐Réglat Annie ,   on behalf of the EULEV Study Group
Published: September 2010

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT
• Levetiracetam has shown good safety/tolerability and efficacy in regulatory trials. This was confirmed in observational investigations performed soon after marketing by using continuation or retention rates as a composite measure.• When an anti‐epileptic drug first becomes available; however, there is evidence of channelling to more severe patients than thereafter. WHAT THIS STUDY ADDS • This study was performed several years after marketing of levetiracetam and found high rates of continuation.• It also further explores this measure by determining the continuation in the absence of initiation of additional anti‐epileptic drugs.AIMS To investigate real‐life effectiveness of levetiracetam in patients initiating treatment in a stable market situation.METHODS Epileptic adults who had initiated levetiracetam between 1 January and 31 August in 2005 or 2006 were included and followed for 1 year by hospital or nonhospital neurologists practising in France. One‐year continuation rates were estimated using Kaplan–Meier analysis. Among those still treated at end of study, treatment goals were investigated. Factors associated with discontinuation were investigated using Cox proportional hazards regression.RESULTS A total of 794 subjects were included in the cohort, and 753 subjects were followed up and included in the analysis. Among these, mean (SD) age was 42.6 (±17.0) years, 51.1% were female, 76.6% had partial epilepsy, 93.5% had seizures in the 6 months preceding levetiracetam initiation and 82.9% had at least one concomitant anti‐epileptic drug when starting levetiracetam. One‐year levetiracetam continuation rate was 83.5% (95% confidence interval, 80.5–86.0%). Of the 579 patients still using levetiracetam at end of study, 46.8% were seizure free during the last 6 months, and 24% were on levetiracetam monotherapy. Reasons for discontinuation (n= 122) were adverse events (45%), lack of efficacy (38%) or both (9%). Levetiracetam discontinuation was most strongly associated with previous exposure to more than four anti‐epileptic drugs, whereas continuation was most strongly associated with presence of seizure‐related falls in the 6 months preceding levetiracetam initiation.CONCLUSIONS This population‐based cohort study in a stable market situation found a high 1 year levetiracetam continuation rate compared with previous studies done sooner after market introduction.
Sensitization to lupine flour: is it clinically relevant?
Authors: De Jong N. W. , Van Maaren M. S. , Vlieg‐Boersta B. J. , Dubois A. E. J. , De Groot H. , Gerth van Wijk R. 
Published: September 2010

SummaryBackground
Lupinus angustifolius (blue lupine) is used for human and animal consumption. Currently, the lupine content in bread varies from 0% to 10% and from 0.5% to 3% in pastry. Although lupine flour is present in many products, anaphylaxis on lupine flour is rarely seen.Objective
The aim of our study was to determine the clinical relevance of sensitization to lupine flour.Methods
From October 2004 until October 2005, we performed skin prick tests (SPT) with lupine flour, peanut and soy extracts in consecutive patients attending our allergy clinic with a suspected food allergy. In patients sensitized to lupine flour, double‐blind placebo‐controlled food challenges (DBPCFC) were performed and specific IgE was measured.Results
We tested 372 patients. SPTs with peanut, soy and lupine flour were positive in 135, 58 and 22 patients, respectively. Nine patients with sensitization to lupine flour underwent DBPCFC, which was negative in eight cases. In contrast, one patient experienced significant symptoms. Four of these nine patients suspected lupine by history. Two other patients with a positive history to lupine declined from challenges. In these patients, a 3‐day dietary record showed that they could consume lupine without symptoms. Specific IgE in the serum was positive for L. angustifolius, peanut and soy in all nine patients.Conclusion
These results demonstrate that clinical lupine allergy is very uncommon, even in the presence of sensitization to lupine flour. The estimated prevalence of lupine allergy, among patients with a suspected food allergy, referred to a tertiary allergy centre in the Netherlands is 0.27–0.81%. In most, although not all cases, sensitization is not clinically relevant and is most likely caused by cross‐sensitization to peanut. In selected cases, eliciting doses are low, making significant reactions possible. Cite this as: N. W. de Jong, M. S. van Maaren, B. J. Vlieg‐Boersta, A. E. J. Dubois, H. de Groot and
R. Gerth van Wijk, Clinical & Experimental Allergy, 2010 (40) 1571–1577.