bluuebunny/crossref_metadata_2025_split huggingface dataset:
Audiences and Outcomes in Online and Traditional American Government Classes Revisited
Authors: Botsch Robert E. , Botsch Carol S. 
Published: June 2012

AbstractIn 1997 we first offered American government classes online as well as face-to-face classes. We administered pre- and posttests to our students to measure their general knowledge of American government, political attitudes, demographics, and some behaviors. Following an initial report in 2001, we continued to gather data for 10 more years; this current study covers nearly 3,200 students during 13 years. We examine the sample as a whole and changes in audiences and outcomes, over time, for the two teaching formats. Although the kinds of students taking online classes have become more similar, a few differences persist. Learning outcome differences continue to be insignificant. Neither format has a clear advantage in students' changes in attitudes, but the online classes increased students' newspaper reading. Class dropout rate and faculty workload both favor face-to-face classes, but flexibility in scheduling and student demand clearly favor online classes.
Punctuated global tropical cyclone activity over the past 5,000 years
Authors: Nott Jonathan , Forsyth Anthony 
Published: June 2012

There are now a substantial number of millennial scale records of tropical cyclones from a variety of locations globally. Some of these, such as those in the Atlantic and Gulf of Mexico, show patterns of long‐term, generally intense, tropical cyclone (TC) behaviour that have been suggested to be due to either variations in ENSO or shifts in the position of the Atlantic High pressure system and the jet stream. Comparisons are made here of the sedimentary overwash records from the Gulf of Mexico and Atlantic Ocean Basin with the overwash records from the north‐west Pacific and beach ridge records from the south‐west Pacific and south east Indian Ocean basins. There is a substantial degree of synchroneity in global intense TC behaviour over the past 3,000 to 5,000 years. One of the most striking aspects of these records is they all display extended alternating periods (centuries to millennia) of relative quiescence and heightened intense TC activity irrespective of both the resolution and type of long‐term TC record. The cause(s) of this punctuated activity are at present difficult to identify but are likely exogenic in origin rather than due to an intrinsic aspect of the records or the methods used to derive them. The identification of punctuated global long‐term TC behaviour is important for understanding future TC activity and for assessing risk to coastal communities.
Modulation of plasmaspheric hiss intensity by thermal plasma density structure
Authors: Chen Lunjin , Thorne Richard M. , Li Wen , Bortnik Jacob , Turner Drew , Angelopoulos Vassilis 
Published: June 2012

Plasmaspheric hiss is an electromagnetic whistler‐mode emission confined to high density regions such as the plasmasphere and plasmaspheric plumes. We present a dayside THEMIS event showing that the hiss emission intensity is strongly modulated by thermal plasma density variations. The calculated local growth rate is small (less than 5 dB/RE) and increases as the plasma density increases, which partly accounts for the modulation. Ray tracing shows that chorus rays, which eventually evolve into plasmaspheric hiss, are focused towards field lines of higher density and defocused away from field lines of lower density. We suggest that the observed modulation is caused by a combined effect of local cyclotron resonant amplification together with ray focusing during propagation.
Calcium sensing receptor regulates cardiomyocyte function through nuclear calcium
Authors: Zhong Xin , Liu Jun , Lu Fanghao , Wang Yuwen , Zhao Yajun , Dong Shiyun , Leng Xiaoning , Jia Jing , Ren Huan , Xu Changqing , Zhang Weihua 
Published: June 2012

AbstractNuclear Ca2+ plays a pivotal role in the regulation of gene expression. IP3 (inositol‐1,4,5‐trisphosphate) is an important regulator of nuclear Ca2+. We hypothesized that the CaR (calcium sensing receptor) stimulates nuclear Ca2+ release through IICR (IP3‐induced calcium release) from perinuclear stores. Spontaneous Ca2+ oscillations and the spark frequency of nuclear Ca2+ were measured simultaneously in NRVMs (neonatal rat ventricular myocytes) using confocal imaging. CaR‐induced nuclear Ca2+ release through IICR was abolished by inhibition of CaR and IP3Rs (IP3 receptors). However, no effect on the inhibition of RyRs (ryanodine receptors) was detected. The results suggest that CaR specifically modulates nuclear Ca2+ signalling through the IP3R pathway. Interestingly, nuclear Ca2+ was released from perinuclear stores by CaR activator‐induced cardiomyocyte hypertrophy through the Ca2+‐dependent phosphatase CaN (calcineurin)/NFAT (nuclear factor of activated T‐cells) pathway. We have also demonstrated that the activation of the CaR increased the NRVM protein content, enlarged cell size and stimulated CaN expression and NFAT nuclear translocation in NRVMs. Thus, CaR enhances the nuclear Ca2+ transient in NRVMs by increasing fractional Ca2+ release from perinuclear stores, which is involved in cardiac hypertrophy through the CaN/NFAT pathway.
First-principles insights on the magnetism of cubic SrTi1−xCoxO3−δ
Authors: Florez J. M. , Ong S. P. , Onbaşli M. C. , Dionne G. F. , Vargas P. , Ceder G. , Ross C. A. 
Published: June 2012

We present hybrid density functional calculations suggesting that magnetism in cubic SrTi1−xCoxO3−δ (STCO) with x = 0.25 is sensitive to the nearest neighbor arrangement of the Co and the presence of oxygen vacancies. Spin polarized calculations for x = 0.25 in which the nearest neighbor (nn) Co spacing is a, 2a or 3a with a the lattice parameter predict lowest energies for the 2a nn separation and favor the ferromagnetic state. Oxygen deficiency (δ=0.125) lowers the average Co valence state and favors mixed valence and spin states (high spin for the Co adjacent to the vacancy and low for the non-adjacent Co), an increase of the band gap and an expansion of the lattice parameter compared to stoichiometric STCO in which both Co ions are low spin. Predicted configurations of the two neighboring Co ions are (t2g5eg0, t2g5eg0) and (t2g4eg2, t2g6eg0) with average 1.0 and 1.6 μB/Co for stoichiometric and 1-O-vacancy systems, respectively.
Very high-temperature impact melt products as evidence for cosmic airbursts and impacts 12,900 years ago
Authors: Bunch Ted E. , Hermes Robert E. , Moore Andrew M.T. , Kennett Douglas J. , Weaver James C. , Wittke James H. , DeCarli Paul S. , Bischoff James L. , Hillman Gordon C. , Howard George A. , Kimbel David R. , Kletetschka Gunther , Lipo Carl P. , Sakai Sachiko , Revay Zsolt , West Allen , Firestone Richard B. , Kennett James P. 
Published: June 2012

It has been proposed that fragments of an asteroid or comet impacted Earth, deposited silica-and iron-rich microspherules and other proxies across several continents, and triggered the Younger Dryas cooling episode 12,900 years ago. Although many independent groups have confirmed the impact evidence, the hypothesis remains controversial because some groups have failed to do so. We examined sediment sequences from 18 dated Younger Dryas boundary (YDB) sites across three continents (North America, Europe, and Asia), spanning 12,000 km around nearly one-third of the planet. All sites display abundant microspherules in the YDB with none or few above and below. In addition, three sites (Abu Hureyra, Syria; Melrose, Pennsylvania; and Blackville, South Carolina) display vesicular, high-temperature, siliceous scoria-like objects, or SLOs, that match the spherules geochemically. We compared YDB objects with melt products from a known cosmic impact (Meteor Crater, Arizona) and from the 1945 Trinity nuclear airburst in Socorro, New Mexico, and found that all of these high-energy events produced material that is geochemically and morphologically comparable, including: (i) high-temperature, rapidly quenched microspherules and SLOs; (ii) corundum, mullite, and suessite (Fe3Si), a rare meteoritic mineral that forms under high temperatures; (iii) melted SiO2glass, or lechatelierite, with flow textures (or schlieren) that form at > 2,200 °C; and (iv) particles with features indicative of high-energy interparticle collisions. These results are inconsistent with anthropogenic, volcanic, authigenic, and cosmic materials, yet consistent with cosmic ejecta, supporting the hypothesis of extraterrestrial airbursts/impacts 12,900 years ago. The wide geographic distribution of SLOs is consistent with multiple impactors.
Ancestral haplotype-based association mapping with generalized linear mixed models accounting for stratification
Authors: Zhang Z. , Guillaume F. , Sartelet A. , Charlier C. , Georges M. , Farnir F. , Druet T. 
Published: June 2012

AbstractMotivation: In many situations, genome-wide association studies are performed in populations presenting stratification. Mixed models including a kinship matrix accounting for genetic relatedness among individuals have been shown to correct for population and/or family structure. Here we extend this methodology to generalized linear mixed models which properly model data under various distributions. In addition we perform association with ancestral haplotypes inferred using a hidden Markov model.Results: The method was shown to properly account for stratification under various simulated scenari presenting population and/or family structure. Use of ancestral haplotypes resulted in higher power than SNPs on simulated datasets. Application to real data demonstrates the usefulness of the developed model. Full analysis of a dataset with 4600 individuals and 500 000 SNPs was performed in 2 h 36 min and required 2.28 Gb of RAM.Availability: The software GLASCOW can be freely downloaded from www.giga.ulg.ac.be/jcms/prod_381171/software.Contact: francois.guillaume@jouy.inra.frSupplementary information: Supplementary data are available at Bioinformatics online.
Mimicking the tumour microenvironment: three different co‐culture systems induce a similar phenotype but distinct proliferative signals in primary chronic lymphocytic leukaemia cells
Authors: Hamilton Emma , Pearce Laurence , Morgan Liam , Robinson Sophie , Ware Vicki , Brennan Paul , Thomas N. Shaun B. , Yallop Deborah , Devereux Stephen , Fegan Chris , Buggins Andrea G. S. , Pepper Chris 
Published: June 2012

SummaryInteractions in the tumour microenvironment can promote chronic lymphocytic leukaemia (CLL) cell survival, proliferation and drug resistance. A detailed comparison of three co‐culture systems designed to mimic the CLL lymph node and vascular microenvironments were performed; two were mouse fibroblast cell lines transfected with human CD40LG or CD31 and the third was a human microvascular endothelial cell line, HMEC‐1. All three co‐culture systems markedly enhanced CLL cell survival and induced a consistent change in CLL cell phenotype, characterized by increased expression of CD38, CD69, CD44 and ITGA4 (CD49d); this phenotype was absent following co‐culture on untransfected mouse fibroblasts. In contrast to HMEC‐1 cells, the CD40LG and CD31‐expressing fibroblasts also induced ZAP70 expression and marked CLL cell proliferation as evidenced by carboxyfluorescein succinimidyl ester labelling and increased Ki‐67 expression. Taken together, our data show that co‐culture on different stroma induced a remarkably similar activation phenotype in CLL cells but only the CD40LG and CD31‐expressing fibroblasts increased ZAP70 expression and CLL cell proliferation, indicating that ZAP70 may play a critical role in this process. This comparative study reveals a number of striking similarities between the co‐culture systems tested but also highlights important differences that should be considered when selecting which system to use for in‐vitro investigations.
River macrophyte indices: not the Holy Grail!
Authors: DEMARS BENOÎT O. L. , POTTS JACQUELINE M. , TRÉMOLIÈRES MICHÈLE , THIÉBAUT GABRIELLE , GOUGELIN NATHALIE , NORDMANN VINCENT 
Published: June 2012

Summary1. Recent studies have demonstrated that there is generally no unambiguous relationship between plant species composition and specific environmental conditions in rivers. Nevertheless, indices of environmental pressures based on macrophytes are flourishing, because of the requirements of the Water Framework Directive (WFD).2. We first reviewed nine such indices against 13 criteria for bioindicators. Then, using data from France and England, we tested whether the IBMR (Macrophyte Biological Index for Rivers) and LEAFPACS (predictions and classification system for macrophytes) methods could reliably indicate nutrient and hydromorphological pressures. Finally, we used an improved bootstrapping method to estimate accuracy.3. Currently, most indices lack ecological meaning for a variety of reasons, including partial sampling (backwaters are excluded); reliance on list of taxa (there are identification difficulties) rather than structure and functions; correlation rather than causation; application within a limited biogeographical area; reliance on ‘expert’ judgement; high precision but poor accuracy; poorly defined reference conditions; lack of independent tests; and an inability to discriminate reliably between the target pressures of interest from confounding background variables.4. IBMR was a far better indicator of pH (or HCO3‐pCO2) than it was of soluble reactive phosphorus, SRP (or SRP‐NH4). While there was a highly significant correlation between IBMR and SRP after removing the effect of pH, the relationship was weak (r2 = 0.08, n = 215, P < 0.001).5. LEAFPACS is a multi‐metric method summing up five individual indices, each compliant with the WFD. Its individual metrics were not better correlated with nutrient and hydromorphological pressures (with r2 < 0.1, n = 62, P < 0.05) than was the IBMR. The meaning of the overall metric is questionable.6. There are problems in determining the precision of the indices, owing to uncertainties in recording, but they are less than the uncertainties in determining accuracy (because species optima and tolerances are sometimes poorly known).7. Reliable information is needed to improve the state of our rivers. Macrophyte indices are able to detect statistically significant pressures from a large population of sites but cannot be applied at specific sites, as required by the WFD, owing to large uncertainties and low explanatory power. Typically, more than 90% of the variability in macrophyte indices is attributed to factors other than human pressure. The WFD would be better served by a simpler, holistic approach based on our current mechanistic understanding of river processes. These findings are likely to apply also to other taxonomic groups (macroinvertebrates, diatoms, fish) used in the assessment of purported ecological quality and to palaeolimnological measures of reference status.
The role of male chromosomal polymorphism played in spermatogenesis and the outcome of IVF/ICSI‐ET treatment
Authors: Guo T. , Qin Y. , Gao X. , Chen H. , Li G. , Ma J. , Chen Z.‐J. 
Published: June 2012

SummaryChromosomal polymorphism has been reported to be associated with infertility, but its effect on IVF/ICSI‐ET outcome is still controversial. To evaluate whether or not chromosomal polymorphism in men plays a role in spermatogenesis and the outcome of IVF/ICSI‐ET, we retrospectively analysed 281 infertile couples. Measures included fertilization rate, implantation rate, pregnancy rate, clinical pregnancy rate, ongoing pregnancy rate, early miscarriage rate and preterm rate. Men with chromosomal polymorphism had significantly higher frequencies of severe oligozoospermia and azoospermia than those without (37.12% vs. 16.11%, p < 0.001; 27.27% vs. 10.74%, p < 0.001; respectively). Significantly, lower fertilization rate (68.02% vs. 78.00%, p < 0.001) and clinical pregnancy rate (45.00% vs. 66.67%, p = 0.031) were observed in polymorphism‐carrying men with severe oligozoospermia compared with non‐carriers with severe oligozoospermia. This suggests that chromosomal polymorphism has adverse effects on spermatogenesis, negatively influencing the outcome of IVF/ICSI‐ET treatment. Polymorphic variations on the Y chromosome have been found to be the most prevalent polymorphism in infertile men, most frequently occurring in patients with severe oligozoospermia.
What are the core elements of patient‐centred care? A narrative review and synthesis of the literature from health policy, medicine and nursing
Authors: Kitson Alison , Marshall Amy , Bassett Katherine , Zeitz Kathryn 
Published: June 2012

AbstractAim.  To identify the common, core elements of patient‐centred care in the health policy, medical and nursing literature.Background.  Healthcare reform is being driven by the rhetoric around patient‐centred care yet no common definition exists and few integrated reviews undertaken.Design.  Narrative review and synthesis.Data sources.  Key seminal texts and papers from patient organizations, policy documents, and medical and nursing studies which looked at patient‐centred care in the acute care setting. Search sources included Medline, CINHAL, SCOPUS, and primary policy documents and texts covering the period from 1990–March 2010.Review methods.  A narrative review and synthesis was undertaken including empirical, descriptive, and discursive papers. Initially, generic search terms were used to capture relevant literature; the selection process was narrowed to seminal texts (Stage 1 of the review) and papers from three key areas (in Stage 2).Results.  In total, 60 papers were included in the review and synthesis. Seven were from health policy, 22 from medicine, and 31 from nursing literature. Few common definitions were found across the literature. Three core themes, however, were identified: patient participation and involvement, the relationship between the patient and the healthcare professional, and the context where care is delivered.Conclusion.  Three core themes describing patient‐centred care have emerged from the health policy, medical, and nursing literature. This may indicate a common conceptual source. Different professional groups tend to focus on or emphasize different elements within the themes. This may affect the success of implementing patient‐centred care in practice.
A physiologically based pharmacokinetics model for florfenicol in crucian carp and oral‐to‐intramuscular extrapolation
Authors: YANG F. , SUN N. , SUN Y. X. , SHAN Q. , ZHAO H. Y. , ZENG D. P. , ZENG Z. L. 
Published: June 2012

Yang, F., Sun, N., Sun, Y. X., Shan, Q., Zhao, H. Y., Zeng, D. P., Zeng, Z. L. A physiologically based pharmacokinetics model for florfenicol in crucian carp and oral‐to‐intramuscular extrapolation. J. vet. Pharmacol. Therap. 36, 192–200.In this study, an oral physiologically based pharmacokinetics (PBPK) model was developed for florfenicol in crucian carp (Carassius auratus). Subsequently, oral‐to‐intramuscular extrapolation was performed and the two models were used to predict florfenicol concentrations in the edible tissues of crucian carp. The oral model gave good predictions in most tissues, except for kidney and liver in which the florfenicol concentrations were underestimated at the later time points. In contrast, using the intramuscular model, the concentrations in the kidney were overestimated at the later time points. Both models had the best predictive ability in the main edible tissue, the muscle. The oral model also accurately predicted the florfenicol concentrations in the muscle after multiple doses. The present study demonstrated the feasibility of predicting florfenicol concentrations in the edible tissues of crucian carp using a route‐to‐route extrapolation method.
Rapid high‐amplitude circumferential slow wave propagation during normal gastric pacemaking and dysrhythmias
Authors: O’Grady G. , Du P. , Paskaranandavadivel N. , Angeli T. R. , Lammers W. J. E. P. , Asirvatham S. J. , Windsor J. A. , Farrugia G. , Pullan A. J. , Cheng L. K. 
Published: June 2012

AbstractBackground  Gastric slow waves propagate aborally as rings of excitation. Circumferential propagation does not normally occur, except at the pacemaker region. We hypothesized that (i) the unexplained high‐velocity, high‐amplitude activity associated with the pacemaker region is a consequence of circumferential propagation; (ii) rapid, high‐amplitude circumferential propagation emerges during gastric dysrhythmias; (iii) the driving network conductance might switch between interstitial cells of Cajal myenteric plexus (ICC‐MP) and circular interstitial cells of Cajal intramuscular (ICC‐IM) during circumferential propagation; and (iv) extracellular amplitudes and velocities are correlated.Methods  An experimental–theoretical study was performed. High‐resolution gastric mapping was performed in pigs during normal activation, pacing, and dysrhythmia. Activation profiles, velocities, and amplitudes were quantified. ICC pathways were theoretically evaluated in a bidomain model. Extracellular potentials were modeled as a function of membrane potentials.Key Results  High‐velocity, high‐amplitude activation was only recorded in the pacemaker region when circumferential conduction occurred. Circumferential propagation accompanied dysrhythmia in 8/8 experiments was faster than longitudinal propagation (8.9 vs 6.9 mm s−1; P = 0.004) and of higher amplitude (739 vs 528 μV; P = 0.007). Simulations predicted that ICC‐MP could be the driving network during longitudinal propagation, whereas during ectopic pacemaking, ICC‐IM could outpace and activate ICC‐MP in the circumferential axis. Experimental and modeling data demonstrated a linear relationship between velocities and amplitudes (P < 0.001).Conclusions & Inferences  The high‐velocity and high‐amplitude profile of the normal pacemaker region is due to localized circumferential propagation. Rapid circumferential propagation also emerges during a range of gastric dysrhythmias, elevating extracellular amplitudes and organizing transverse wavefronts. One possible explanation for these findings is bidirectional coupling between ICC‐MP and circular ICC‐IM networks.
Decision influences and aftermath: parents, stillbirth and autopsy
Authors: Horey Dell , Flenady Vicki , Conway Liz , McLeod Emma , Yee Khong Teck 
Published: June 2012

AbstractBackground  Stillbirth, among the most distressing experiences an adult may face, is also a time when parents must decide whether an autopsy or other post‐mortem examinations will be performed on their infant. Autopsies can reveal information that might help explain stillbirth, yet little is known about how people make this difficult decision.Objectives  This study examines the influences on decisions about autopsy after stillbirth among Australian parents.Design  The study involved secondary analysis of transcripts of three focus groups using qualitative content analysis.Participants and setting  Seventeen parents of 14 stillborn babies participated in consultations around the revision of a perinatal mortality audit guideline.Results  Parents shared the decision making. Four decision drivers were identified: parents’ preparedness or readiness to make decisions; parental responsibility; concern for possible consequences of an autopsy and the role of health professionals. Each decision driver involved reasons both for and against autopsy. Two decision aftermath were also present: some parents who agreed to an autopsy were dissatisfied with the way the autopsy results were given to them and some parents who did not have an autopsy for their infant expressed some form of regret or uncertainty about the choice they made.Conclusions  To make decisions about autopsy after stillbirth, parents need factual information about autopsy procedures, recognition that there might be fear of blame, an environment of trust, and health services and professionals prepared and skilled for difficult conversations.