bluuebunny/crossref_metadata_2025_split huggingface dataset:
Efficacy of a New Accelerated Streptokinase Regime in Acute Myocardial Infarction: A Double Blind Randomized Clinical Trial
Authors: Ghaffari Samad , Kazemi Babak , Golzari Iraj Gorbani 
Published: August 2011

SUMMARYBackground: Studies of thrombolysis in acute ST‐elevation myocardial infarction (STEMI) have focused on differences in outcome between groups receiving various regimes. Expedited treatment may influence the efficacy of nonfibrin specific thrombolytic agents in restoring early patency of the infarct‐related artery (IRA), which is a major determinant of survival after ST‐elevation myocardial infarction (STEMI). Methods: We performed a randomized double blind clinical trial comparing an accelerated infusion (1.5 MU/20 min; group A, n = 200) with the conventional infusion (1.5 MU/60 min; group B, n = 100) of streptokinase (SK) in 300 patients with their first episode of acute STEMI. Demographics, clinical reperfusion rates, angiographic study findings, left ventricular ejection fraction (LVEF), in‐hospital morbidity and mortality and one year mortality were compared between two groups. Results: Mean age was 59 ± 12 years (79% male). There were no differences in baseline data between groups. Clinical, electrocardiographic and physiologic reperfusion indices revealed significant faster and higher reperfusion rates and better preserved LVEF at discharge in group A. Sixty‐three percent of patients in either group underwent invasive coronary angiography at a mean of 5 days with comparable findings. Atrial fibrillation, malignant ventricular arrhythmias in the second day, in‐hospital and late mortalities rates occurred more frequently in group B patients. In multivariate analysis, accelerated SK infusion was the only independent predictor of higher electrocardiographic reperfusion (OR = 3.2, CI: 1.93–5.3, P < 0.001). Conclusions: The accelerated SK infusion regimen of 1.5 MU in 20 min is safe and well tolerated with significantly faster and higher clinical reperfusion rates, more preserved LV systolic function, less atrial and ventricular sustained arrhythmias, and less in‐hospital and 1 year mortality rates in acute STEMI.
Modelling regional scale biofuel scenarios – a case study for India
Authors: Das Subhashree , Priess Joerg A. , Schweitzer Christian 
Published: August 2011

AbstractBiofuel initiatives in India have gained momentum with the national biofuel policy targeting 20% blending of both petrol and diesel by 2017. Most of India's biofuel plans revolve around using sugarcane for bioethanol and jatropha for biodiesel production. This study, taking the southern Indian state of Karnataka as an example, aims at estimating the potential to achieve policy targets. The study spatially analyses land‐use change owing to biofuel expansion and its effects on food production. We used an integrated modelling framework to simulate land‐use change and bioenergy production under two scenarios – Industrial Economy (IE) and Agricultural Economy (AE). Results indicate that meeting the 20% blending target is a challenging goal to achieve under both scenarios. Bioethanol requirements can be nearly fulfilled (88% under IE and 93% under AE) because of sugarcane expansion. However, biodiesel demands cannot be fulfilled using only degraded lands as currently planned in India, but additional agricultural land (3–4% of the total cropland) will be required for jatropha‐based biodiesel production. Food production will not be directly impacted until 2025, because the largest source of additional land could be short‐ and long‐term fallows. We conclude that conservation oriented initiatives, such as water harvesting and energy conservation measures can increase productivities of biofuel crops and reduce fuel demands, respectively. State support and Clean Development Mechanism opportunities can enhance economic incentives for energy cropping. Therefore, a simultaneous and multipronged approach is needed to accommodate food and fuel demands in India.
Comparative interpretation of count, presence–absence and point methods for species distribution models
Authors: Aarts Geert , Fieberg John , Matthiopoulos Jason 
Published: August 2011

Summary1. The need to understand the processes shaping population distributions has resulted in a vast increase in the diversity of spatial wildlife data, leading to the development of many novel analytical techniques that are fit‐for‐purpose. One may aggregate location data into spatial units (e.g. grid cells) and model the resulting counts or presence–absences as a function of environmental covariates. Alternatively, the point data may be modelled directly, by combining the individual observations with a set of random or regular points reflecting habitat availability, a method known as a use‐availability design (or, alternatively a presence – pseudo‐absence or case–control design).2. Although these spatial point, count and presence–absence methods are widely used, the ecological literature is not explicit about their connections and how their parameter estimates and predictions should be interpreted. The objective of this study is to recapitulate some recent statistical results and illustrate that under certain assumptions, each method can be motivated by the same underlying spatial inhomogeneous Poisson point process (IPP) model in which the intensity function is modelled as a log‐linear function of covariates.3. The Poisson likelihood used for count data is a discrete approximation of the IPP likelihood. Similarly, the presence–absence design will approximate the IPP likelihood, but only when spatial units (i.e. pixels) are extremely small (Electric Journal of Statistics, 2010, 4, 1151–1201). For larger pixel sizes, presence–absence designs do not differentiate between one or multiple observations within each pixel, hence leading to information loss.4. Logistic regression is often used to estimate the parameters of the IPP model using point data. Although the response variable is defined as 0 for the availability points, these zeros do not serve as true absences as is often assumed; rather, their role is to approximate the integral of the denominator in the IPP likelihood (The Annals of Applied Statistics, 2010, 4, 1383–1402). Because of this common misconception, the estimated exponential function of the linear predictor (i.e. the resource selection function) is often assumed to be proportional to occupancy. Like IPP and count models, this function is proportional to the expected density of observations.5. Understanding these (dis‐)similarities between different species distribution modelling techniques should improve biological interpretation of spatial models and therefore advance ecological and methodological cross‐fertilization.
PRINCIPLES OF BEHAVIOURAL TAXONOMY AND THE MATHEMATICAL BASIS OF THE TAXONOME COMPUTER PROGRAM
Authors: Cattell Raymond B. , Coulter Malcolm A. 
Published: August 2011

Types are modes in a multidimensional distribution, and can be found either by operating on a Q‐matrix of distances between individuals or by calculating densities in Cartesian sub‐spaces. Pursuing the former approach, reasons are given for preferring the family of rp ‘coefficients of likeness’ to Mahalanobis' D or other distance measures. A general formula is presented for rp, applicable to factors of any obliqueness and any assigned weight, permitting classification by what an individual docs as well as by what he is.Classification procedures require recognition of the differences between types as homostats and as segregates. A homostat is a set of unusually similar people: a segregate is a series with above average similarities which thus has continuity, although there may be negligible resemblance between first and last members. A Boolean algorithm will objectively find homostats and sort them into phenomenal and nuclear clusters, and a further algorithm will operate on these to locate segregates. These steps have been combined in a computer program called Taxonome, two examples of the application of which are given. Search for types is a topographical descriptive procedure in which finding the ‘texture’ of a whole domain is as important as the location of individual types. Type analysis contributes to non‐linear prediction, to theories of type origin, and to higher order systematization and conceptualization.
SYSTEMS WITH RESPONSE‐DEPENDENT DEAD TIME
Authors: Hoopen M. Ten , Reuver H. A. 
Published: August 2011

Conrad's (1951) data on the performance of a human operator who has to respond to a complex temporal sequence of stimuli (obtained by a parallel arrangement of two, three or four signal sources and each delivering periodic signals) are compared with the properties of three kinds of signal processing systems, each constituting special cases of a general concept. In model I a simple dead time is assumed, while in models II and III the dead time after each response is a linear function of the preceding inter‐response interval duration.It is argued that the mean number of errors per unit of time, the criterion used so far, is a somewhat crude measure and that more decisive conclusions can be drawn when a more detailed description of the timing of the responses is available; for instance, in the form of the probability density function, or the joint probability density function of the response interval durations. The models may also find application in neuronal spike train analysis, and for problems in the field of operations research.
Multiple choice tests: Power, length and optimal number of choices per item
Authors: Andrés A. Martín , del Castillo J.D. Luna 
Published: August 2011

In an earlier paper (Martín Andrés & Luna del Castillo, 1989), three statistical tests for assigning a mark for a student in multiple choice tests were set out. In the present paper, the authors give the power of all three tests, for the purpose of selecting the best one for each particular case. They also give the formulae for determining the minimum number of questions (sample size) for an examination with k alternatives (only one of which is the correct answer), to satisfy given requirements about the number of students one wishes to pass or fail undeservedly (formulae which are also valid for giving any other mark, or for deciding the student's level of knowledge with given exactitude).Finally, the authors prove that, under certain very general conditions, it is better to set questions with k = 3 alternative answers, whilst under another criterion, the value k = 2 is to be preferred.The results are compared with the equivalent classic methods.
A comparison of four methods of calculating standard errors of maximum‐likelihood estimates in the analysis of covariance structure
Authors: Dolan Conor V. , Molenaar Peter C. M. 
Published: August 2011

Four methods of calculating standard errors (SEs) in the analysis of covariance structure using normal theory maximum‐likelihood estimation, namely LISREL SEs, SEs derived from the exact Hessian, SEs derived from the finite difference approximation to the Hessian using exact gradients, and SEs derived from the update of the Hessian obtained during quasi‐Newton optimization, are compared.Two comparisons are made. The first is based on 30 data sets simulated according to an orthogonal common factor model. The second is based on the analysis of a well known data set concerning the stability of alienation.The finite difference and exact SEs are identical to at least four places of decimals. Little difference is observed between the remaining SEs.
Factor analysis of variables with 2, 3, 5 and 7 response categories: A comparison of categorical variable estimators using simulated data
Authors: Dolan Conor V. 
Published: August 2011

Two estimators in the factor analysis of categorical items are studied, the weighted least squares function implemented in the tandem PRELIS‐LISREL 7 and a generalized least squares function implemented in LISCOMP. Of main interest is the performance of these estimators in relatively small samples (200 to 400) and the comparison of their performance with the normal theory maximum likelihood estimator given an increasing number of response categories. The evaluation of the performance of these estimators concerns the variability of the parameter estimates, the bias of the parameter estimates, the distribution of the parameter estimates and the χ2 goodness‐of‐fit statistics. The model used in the simulation is an 8‐indicator single common factor model. The effect of model size (12‐ and 16‐indicator models) on the categorical item estimator of LISREL 7 is investigated briefly.The results indicate that in the ideal circumstances of the simulation study, 200 is too small a sample size to justify the use of large sample statistics associated with these estimators.
A latent trait and a latent class model for mixed observed variables
Authors: Moustaki Irini 
Published: August 2011

Latent variable models are widely used in social sciences in which interest is centred on entities such as attitudes, beliefs or abilities for which there exist no direct measuring instruments. Latent modelling tries to extract these entities, here described as latent (unobserved) variables, from measurements on related manifest (observed) variables. Methodology already exists for fitting a latent variable model to manifest data that is either categorical (latent trait and latent class analysis) or continuous (factor analysis and latent profile analysis).In this paper a latent trait and a latent class model are presented for analysing the relationships among a set of mixed manifest variables using one or more latent variables. The set of manifest variables contains metric (continuous or discrete) and binary items. For the latent trait model the latent variables are assumed to follow a multivariate standard normal distribution. Our method gives maximum likelihood estimates of the model parameters and standard errors of the estimates by analysing the data as they are without using any underlying variables. The mixed latent trait and latent class models are fitted using an EM algorithm.To illustrate the use of the mixed model three data sets have been analysed. Two of the data sets contain five memory questions, the first on Thatcher's resignation and the second on the Hillsborough football disaster; these five questions were included in British Market Research Bureau International August 1993 face‐to‐face omnibus survey. The third data set is from the 1991 British Social Attitudes Survey; the questions which have been analysed are from the environment section.
Reduced Antibody Responses to the Pandemic (H1N1) 2009 Vaccine after Recent Seasonal Influenza Vaccination
Authors: Choi Yoon Seok , Baek Yun Hee , Kang Wonseok , Nam Seung Joo , Lee Jino , You Sooseong , Chang Dong-Yeop , Youn Jong-Chan , Choi Young Ki , Shin Eui-Cheol 
Published: August 2011

ABSTRACT
The vaccination program against the 2009 pandemic H1N1 influenza virus (2009 H1N1) provided a unique opportunity to determine if immune responses to the 2009 H1N1 vaccine were affected by a recent, prior vaccination against seasonal influenza virus. In the present study, we studied the immune responses to the 2009 H1N1 vaccine in subjects who either received the seasonal influenza virus vaccination within the prior 3 months or did not. Following 2009 H1N1 vaccination, subjects previously given a seasonal influenza virus vaccination exhibited significantly lower antibody responses, as determined by hemagglutination inhibition assay, than subjects who had not received the seasonal influenza virus vaccination. This result is compatible with the phenomenon of “original antigenic sin,” by which previous influenza virus vaccination hampers induction of immunity against a new variant. Our finding should be taken into account for future vaccination programs against pandemic influenza virus outbreaks.
Detection of Mycoplasma genitalium-Reactive Cervicovaginal Antibodies among Infected Women
Authors: Iverson-Cabral Stefanie L. , Manhart Lisa E. , Totten Patricia A. 
Published: August 2011

ABSTRACTMycoplasma genitalium-reactive cervicovaginal IgA and IgG antibodies were detected in 51.9% and 70.4% of 27 infected women and 22.2% and 18.5% of 27 uninfected controls, respectively. The predominance of MgpB- and MgpC-reactive antibodies at the site of infection is consistent with their hypothesized role in selecting antigenic variants during persistent infection.
The Genome of Yoka Poxvirus
Authors: Zhao Guoyan , Droit Lindsay , Tesh Robert B. , Popov Vsevolod L. , Little Nicole S. , Upton Chris , Virgin Herbert W. , Wang David 
Published: August 2011

ABSTRACT

Yoka poxvirus was isolated almost four decades ago from a mosquito pool in the Central African Republic. Its classification as a poxvirus is based solely upon the morphology of virions visualized by electron microscopy. Here we describe sequencing of the Yoka poxvirus genome using a combination of Roche/454 and Illumina next-generation sequencing technologies. A single consensus contig of ∼175 kb in length that encodes 186 predicted genes was generated. Multiple methods were used to show that Yoka poxvirus is most closely related to viruses in the
Orthopoxvirus
genus, but it is clearly distinct from previously described poxviruses. Collectively, the phylogenetic and genomic sequence analyses suggest that Yoka poxvirus is the prototype member of a new genus in the family
Poxviridae
.
Nuclear magnetic resonance and mass spectrometry studies of 2′,3′,5′-O-triacetylguanosine self-assembly in the presence of alkaline earth metal ions (Ca2+, Sr2+, Ba2+)
Authors: Kwan Irene C.M. , She Yi-Min , Wu Gang 
Published: August 2011

We report structural determination of cation-templated self-assembly of a guanosine derivative, 2′,3′,5′-O-triacetylguanosine (TAG), in the presence of three alkaline earth metal ions (Ca2+, Sr2+, and Ba2+) in CDCl3. Using a combination of nuclear magnetic resonance (NMR) and electrospray ionization mass spectrometry (ESI-MS) methods, we have found that TAG molecules form discrete octamers in the form of [TAG]8M2+ (M2+ = Ca2+, Sr2+, and Ba2+), which is composed of two G-quartets and a sandwiched metal ion. We have determined the ability of the three alkaline earth metal ions to promote TAG self-assembly (relative binding affinity) to be Sr2+ ≫ Ba2+ > Ca2+. More importantly, we have used two-dimensional (2D) NMR methods to determine the structural details of [TAG]8Sr2+. In particular, we found that each octamer consists of an all-anti G-quartet stacking on top of an all-syn G-quartet in a tail-to-head fashion with a twist angle of 45° between the two G-quartets. This TAG octamer structure represents a unique case quite different from other lipophilic guanosine octamers reported in the literature.
Phosphorus-31 and vanadium-51 solid-state nuclear magnetic resonance spectroscopy of β-vanadyl phosphate — Effects of homo- and heteronuclear spin-spin, electrostatic, and paramagnetic interactions
Authors: Eichele Klaus , Grimmer Arnd-Rüdiger 
Published: August 2011

Field-dependent 31P solid-state NMR studies demonstrate that the line shape in spectra of β-VOPO4 depends on 51V–31P direct and indirect spin-spin interactions (M2 (51V, 31P) = 101(23) × 106 rad2 s–2, 2Jiso (51V, 31P) = 48(5) Hz) and, to a lesser extent, on 31P chemical shift anisotropy (δiso = –10.4(2), Ω = δ11 – δ33 = 22(2) ppm) and 31P–31P interactions (M2 (31P, 31P) = 6.7(1) × 106 rad2 s–2). In contrast, homonuclear dipolar interactions play an important role for the field and spinning rate dependent 31P spin-lattice relaxation via paramagnetic impurities (T1 = 20–60 s). Vanadium-51 magic-angle spinning NMR spectra indicate a sizeable chemical shift anisotropy (δiso = –754(1), δ11 = –336(10), δ22 = –344(6), δ33 = –1581(8) ppm) and nuclear quadrupole interaction (χ = 1.5(1) MHz, η = 0.35(5)); the principal axis systems of both interactions are clearly not coincident, with an angle of 35(5)° between the greatest component of the electric field gradient tensor and δ33.
A simplified and cost-effective enrichment protocol for the isolation of Campylobacter spp. from retail broiler meat without microaerobic incubation
Authors: Zhou Ping , Hussain Syeda K , Liles Mark R , Arias Covadonga R , Backert Steffen , Kieninger Jessica , Oyarzabal Omar A 
Published: August 2011

Abstract

Background
To simplify the methodology for the isolation of Campylobacter spp. from retail broiler meat, we evaluated 108 samples (breasts and thighs) using an unpaired sample design. The enrichment broths were incubated under aerobic conditions (subsamples A) and for comparison under microaerobic conditions (subsamples M) as recommended by current reference protocols. Sensors were used to measure the dissolved oxygen (DO) in the broth and the percentage of oxygen (O2) in the head space of the bags used for enrichment. Campylobacter isolates were identified with multiplex PCR assays and typed using pulsed-field gel electrophoresis (PFGE). Ribosomal intergenic spacer analyses (RISA) and denaturing gradient gel electrophoresis (DGGE) were used to study the bacterial communities of subsamples M and A after 48 h enrichment.

Results
The number of Campylobacter positive subsamples were similar for A and M when all samples were combined (P = 0.81) and when samples were analyzed by product (breast: P = 0.75; thigh: P = 1.00). Oxygen sensors showed that DO values in the broth were around 6 ppm and O2 values in the head space were 14-16% throughout incubation. PFGE demonstrated high genomic similarity of isolates in the majority of the samples in which isolates were obtained from subsamples A and M. RISA and DGGE results showed a large variability in the bacterial populations that could be attributed to sample-to-sample variations and not enrichment conditions (aerobic or microaerobic). These data also suggested that current sampling protocols are not optimized to determine the true number of Campylobacter positive samples in retail boiler meat.

Conclusions
Decreased DO in enrichment broths is naturally achieved. This simplified, cost-effective enrichment protocol with aerobic incubation could be incorporated into reference methods for the isolation of Campylobacter spp. from retail broiler meat.