bluuebunny/crossref_metadata_2025_split huggingface dataset:
Clinical and multiple gene expression variables in survival analysis of breast cancer: Analysis with the hypertabastic survival model
Authors: Tabatabai Mohammad A , Eby Wayne M , Nimeh Nadim , Li Hong , Singh Karan P 
Published: December 2012

Abstract

Background
We explore the benefits of applying a new proportional hazard model to analyze survival of breast cancer patients. As a parametric model, the hypertabastic survival model offers a closer fit to experimental data than Cox regression, and furthermore provides explicit survival and hazard functions which can be used as additional tools in the survival analysis. In addition, one of our main concerns is utilization of multiple gene expression variables. Our analysis treats the important issue of interaction of different gene signatures in the survival analysis.

Methods
The hypertabastic proportional hazards model was applied in survival analysis of breast cancer patients. This model was compared, using statistical measures of goodness of fit, with models based on the semi-parametric Cox proportional hazards model and the parametric log-logistic and Weibull models. The explicit functions for hazard and survival were then used to analyze the dynamic behavior of hazard and survival functions.

Results
The hypertabastic model provided the best fit among all the models considered. Use of multiple gene expression variables also provided a considerable improvement in the goodness of fit of the model, as compared to use of only one. By utilizing the explicit survival and hazard functions provided by the model, we were able to determine the magnitude of the maximum rate of increase in hazard, and the maximum rate of decrease in survival, as well as the times when these occurred. We explore the influence of each gene expression variable on these extrema. Furthermore, in the cases of continuous gene expression variables, represented by a measure of correlation, we were able to investigate the dynamics with respect to changes in gene expression.

Conclusions
We observed that use of three different gene signatures in the model provided a greater combined effect and allowed us to assess the relative importance of each in determination of outcome in this data set. These results point to the potential to combine gene signatures to a greater effect in cases where each gene signature represents some distinct aspect of the cancer biology. Furthermore we conclude that the hypertabastic survival models can be an effective survival analysis tool for breast cancer patients.
Investigation of motility and biofilm formation by intestinal Campylobacter concisus strains
Authors: Lavrencic Peter , Kaakoush Nadeem O , Huinao Karina D , Kain Nupur , Mitchell Hazel M 
Published: December 2012

Abstract
Motility helps many pathogens swim through the highly viscous intestinal mucus. Given the differing outcomes of Campylobacter concisus infection, the motility of eight C. concisus strains isolated from patients with Crohn’s disease (n=3), acute (n=3) and chronic (n=1) gastroenteritis and a healthy control (n=1) were compared. Following growth on solid or liquid media the eight strains formed two groups; however, the type of growth medium did not affect motility. In contrast, following growth in viscous liquid medium seven of the eight strains demonstrated significantly decreased motility. In media of increasing viscosities the motility of C. concisus UNSWCD had two marked increases at viscosities of 20.0 and 74.7 centipoises. Determination of the ability of UNSWCD to swim through a viscous medium, adhere to and invade intestinal epithelial cells showed that while adherence levels significantly decreased with increasing viscosity, invasion levels did not significantly change. In contrast, adherence to and invasion of UNSWCD to mucus-producing intestinal cells increased upon accumulation of mucus, as did bacterial aggregation. Given this aggregation, we determined the ability of the eight C. concisus strains to form biofilms, and showed that all strains formed biofilms. In conclusion, the finding that C. concisus strains could be differentiated into two groups based on their motility may suggest that strains with high motility have an increased ability to swim through the intestinal mucus and reach the epithelial layer.
Sex difference in race performance and age of peak performance in the Ironman Triathlon World Championship from 1983 to 2012
Authors: Rüst Christoph A , Knechtle Beat , Rosemann Thomas , Lepers Romuald 
Published: December 2012

Abstract

Background
The fastest Ironman race times in ‘Ironman Hawaii’ were achieved in very recent years. This study investigated the change in sex difference in both race performance and the age of peak performance across years in the top ten athletes for split disciplines and overall race time in the ‘Ironman Hawaii’ between 1983 and 2012.

Methods
Changes in split times, overall race times, and age of athletes across years for the top ten overall and the fastest swimmers, cyclists, and runners were investigated using regression analyses and analyses of variance.

Results
Between 1983 and 2012, the overall top ten men and women finishers improved their swimming (only men), cycling, running, and overall race times. The sex difference in overall race time decreased significantly (p = 0.01) from 15.2% to 11.3% across time. For the split disciplines, the sex difference remained unchanged (p > 0.05) for swimming (12.5 ± 3.7%) and cycling (12.5 ± 2.7%) but decreased for running from 13.5 ± 8.1% to 7.3 ± 2.9% (p = 0.03). The time performance of the top ten swimmers remained stable (p > 0.05), while those of the top ten cyclists and top ten runners improved (p < 0.01). The sex difference in performance remained unchanged (p > 0.05) in swimming (8.0 ± 2.4%), cycling (12.7 ± 1.8%), and running (15.2 ± 3.0%). Between 1983 and 2012, the age of the overall top ten finishers and the fastest swimmers, cyclists, and runners increased across years for both women and men (p < 0.01).

Conclusions
To summarize, for the overall top ten finishers, the sex difference decreased across years for overall race time and running, but not for swimming and cycling. For the top ten per discipline, the sex difference in performance remained unchanged. The athletes improved their performances across years although the age of peak performance increased.
Novel variations in the adiponectin gene (ADIPOQ) may affect distribution of oligomeric complexes
Authors: Kottyan Leah C , Woo Jessica G , Keddache Mehdi , Banach Walter , Crimmins Nancy A , Dolan Lawrence M , Martin Lisa J 
Published: December 2012

Abstract
Adiponectin is an obesity related protein that mediates the risk of type 2 diabetes in obese individuals with its anti-inflammatory and insulin-sensitizing properties. To date, five functional variations have been identified in the adiponectin gene. However, these variations are rare, and fail to fully explain adiponectin variability, suggesting unidentified causal variations exist. Thus, our objective was to identify novel, potentially functional amino acid-changing variations in ADIPOQ exonic regions and relate them to oligomeric forms of adiponectin in serum. We sequenced ADIPOQ exons in 30 adolescents chosen from a school-based cohort based on serum adiponectin and insulin levels. Four coding region changes were identified: a methionine initiation skip (MIS), P32L, R55C, and Y111H, of which R55C and Y111H have been previously identified. Individuals with the novel variations and R55C had low levels of adiponectin and decreased adiponectin oligomerization compared to adolescents with similar body mass index and insulin levels. Further, bioinformatic analysis predicted putative functionality of these variations. In our study, Y111H was unrelated to total circulating adiponectin or adiponectin oligomerization. Given the disruption of adiponectin oligomerization in the individuals with MIS, P32L, and R55C coding changes, these variations may lead to increased metabolic disease risk and warrant further examination in larger cohorts.
2-Arachidonoyl-glycerol- and arachidonic acid-stimulated neutrophils release antimicrobial effectors against E. coli, S. aureus, HSV-1, and RSV
Authors: Chouinard François , Turcotte Caroline , Guan Xiaochun , Larose Marie-Chantal , Poirier Samuel , Bouchard Line , Provost Véronique , Flamand Louis , Grandvaux Nathalie , Flamand Nicolas 
Published: December 2012

Abstract
Neutrophils activated with nanomolar concentrations of 2-arachidonoyl-glycerol or arachidonic acid, release antimicrobial effectors, unraveling these lipids as possible regulators of host defense in vivo.
The endocannabinoid 2-AG is highly susceptible to its hydrolysis into AA, which activates neutrophils through de novo LTB4 biosynthesis, independently of CB activation. In this study, we show that 2-AG and AA stimulate neutrophils to release antimicrobial effectors. Supernatants of neutrophils activated with nanomolar concentrations of 2-AG and AA indeed inhibited the infectivity of HSV-1 and RSV. Additionally, the supernatants of 2-AG- and AA-stimulated neutrophils strongly impaired the growth of Escherichia coli and Staphylococcus aureus. This correlated with the release of a large amount (micrograms) of α-defensins, as well as a limited amount (nanograms) of LL-37. All the effects of AA and 2-AG mentioned above were prevented by inhibiting LTB4 biosynthesis or by blocking BLT1. Importantly, neither CB2 receptor agonists nor antagonists could mimic nor prevent the effects of 2-AG, respectively. In fact, qPCR data show that contaminating eosinophils express ∼100-fold more CB2 receptor mRNA than purified neutrophils, suggesting that CB2 receptor expression by human neutrophils is limited and that contaminating eosinophils are likely responsible for the previously documented CB2 expression by freshly isolated human neutrophils. The rapid conversion of 2-AG to AA and their subsequent metabolism into LTB4 promote 2-AG and AA as multifunctional activators of neutrophils, mainly exerting their effects by activating the BLT1. Considering that nanomolar concentrations of AA or 2-AG were sufficient to impair viral infectivity, this suggests potential physiological roles for 2-AG and AA as regulators of host defense in vivo.
Pindaric Temporality, Goethe's Augenblick, and the Invariant Plot of Tiutchev's Lyric
Authors: Maslov Boris 
Published: December 2012

This article puts forward a genealogy of one of the principal temporalities associated with German (pre-)Romantic lyric, the time of a privileged moment (“ewiger/prägnanter Augenblick”). The same temporality is shown to dominate the lyric oeuvre of Fyodor Tiutchev, a Russian Romantic, the proximity of whose poetics to German models is otherwise well documented. As the article maintains, this distinct presentist temporality, along with a concomitant metaphysical stance on the relation between the human and the divine realms, ultimately derives from Pindar's victory odes, which are argued to represent a key resource both for the ideal of lyric propagated in Germany in the Geniezeit and (more unexpectedly) for Tiutchev's lyric practice. The first two sections of the article contain an overview of the chief temporal categories that occur in Pindar's corpus (and, more generally, in Ancient Greek literature of the archaic period) and a discussion of the ways in which his temporal imagination relates to the ideological concerns of the victory ode.
Beyond these specific objectives, which lie in the fields of literary and conceptual history, the article discusses the theoretical implications of a close association between distinct temporal patterns and poetic genres, as well as the issue of the priority of literary vs. philosophical influences on cultural perceptions of time.
Biomechanics of human bipedal gallop: asymmetry dictates leg functions
Authors: Fiers Pieter , De Clercq Dirk , Segers Veerle , Aerts Peter 
Published: December 2012

Summary
Unilateral skipping or bipedal galloping is one of the gait types humans are able to perform. In contrast to many animals, where gallop is the preferred gait at higher speeds, human bipedal gallop only occurs spontaneously in very specific conditions (e.g. fast down-hill locomotion). This study examines the lower limb mechanics and explores the possible reasons why humans do not spontaneously opt for gallop for steady state locomotion on level ground. In 12 subjects, who were required to run and gallop overground at their preferred speed, kinematic and kinetic data were collected and mechanical work at the main lower limb joints (hip, knee, ankle) was calculated. In a separate treadmill experiment, metabolic costs were measured. Analysis revealed that the principal differences between running and galloping are located at the hip. The asymmetrical configuration of gallop involves distinct hip actions and foot placing, giving galloping legs different functions compared with running legs: the trailing leg decelerates the body in vertical direction but propels it forward while the leading leg acts in the opposite way. Although both legs conserve mechanical energy by interchanging external mechanical energy with potential elastic energy, the specific orientation of the legs causes more energy dissipation and generation compared with running. This makes gallop metabolically more expensive and involves high muscular stress at the hips which may be the reasons why humans do not use gallop for steady state locomotion.
Feed-forward and visual feed-back control of head roll orientation in wasps (Polistes humilis, Vespidae, Hymenoptera)
Authors: Viollet Stéphane , Zeil Jochen 
Published: December 2012

SummaryFlying insects keep their visual system horizontally aligned suggesting that gaze stabilization is a crucial first step in flight control. Unlike flies, hymenopteran insects, such as bees and wasps do not have halteres that provide fast, feed-forward angular rate information to stabilize head orientation in the presence of body rotations. We tested whether hymenopteran insects use inertial (mechano-sensory) information to control head orientation from other sources, such as the wings, by applying periodic roll perturbations to male Polistes humilis wasps flying in tether under different visual conditions indoors and in natural outdoor conditions. We oscillated the insects' thorax with frequency modulated sinusoids (chirps) with frequencies increasing from 0.2Hz to 2Hz at a maximal amplitude of 50° peak-to-peak and maximal angular velocity of ±245°/s. We found that head roll stabilization is best outdoors, but completely absent in uniform visual conditions and in darkness. Step responses confirm that compensatory head roll movements are purely visually driven. Modelling step responses indicates that head roll stabilization is achieved by merging information on head angular velocity presumably provided by motion-sensitive with information on head orientation, presumably provided by light level integration across the compound eyes and/or ocelli (dorsal light response). Body roll in free flight reaches amplitudes of ±40° and angular velocities greater than 1000°/s, while head orientation remains horizontal for most of the time to within ±10°. In free flight, we did not find a delay between spontaneous body roll and compensatory head movements and suggest that this is evidence for the contribution of a feed-forward control to head stabilization.
Electrical Properties of Amorphous Carbon Semiconductor Prepared Using a Naphthalene Precursor
Authors: Inoue Yasunori , Sugano Mayo , Kawakami Shunsuke , Kitano Masaaki , Nakajima Kiyotaka , Kato Hideki , Hara Michikazu 
Published: December 2012

Abstract
An amorphous carbon (a-C) semiconductor was prepared by the pyrolysis of naphthalene in the presence of AlCl3 under a nitrogen gas flow. Electrical properties, such as the Seebeck coefficient (S) and electrical conductivity (σ), of the a-C materials were studied as a function of the heat treatment temperature (773–1273 K) and time (5–30 h). The electrical conductivity of a-C increased with the heating temperature. At a heating temperature of 873 K, a-C exhibits p-type semiconducting behavior (S = 0.41 mV K−1, σ = 2.0 × 10−5 S cm−1) and consists of a mixture of sp2-bonded carbon sheets (average sheet size: ca. 1.0 nm) and polycyclic aromatic hydrocarbons (PAH). After prolonged heat treatment (30 h) at 873 K, the electrical conductivity of a-C was increased by a factor of approximately 50 without loss of the semiconductivity (S = 0.20 mV K−1, σ = 9.6 × 10−4 S cm−1). The increase in the electrical conductivity of a-C is attributed to the decomposition of insulating PAH compounds by the prolonged heat treatment. Thus, precise control of the heating temperature and time has a significant effect on the p-type semiconductivity and electrical conductivity of a-C materials.
Quantification of Globotriaosylsphingosine in Plasma and Urine of Fabry Patients by Stable Isotope Ultraperformance Liquid Chromatography–Tandem Mass Spectrometry
Authors: Gold Henrik , Mirzaian Mina , Dekker Nick , Joao Ferraz Maria , Lugtenburg Johan , Codée Jeroen DC , van der Marel Gijs A , Overkleeft Herman S , Linthorst Gabor E , Groener Johanna EM , Aerts Johannes M , Poorthuis Ben JHM 
Published: December 2012

BACKGROUND
Biochemical markers that accurately reflect the severity and progression of disease in patients with Fabry disease and their response to treatment are urgently needed. Globotriaosylsphingosine, also called lysoglobotriaosylceramide (lysoGb3), is a promising candidate biomarker.

METHODS
We synthesized lysoGb3 and isotope-labeled [5,6,7,8,9] 13C5-lysoGb3 (internal standard). After addition of the internal standard to 25 μL plasma or 400 μL urine from patients with Fabry disease and healthy controls, samples were extracted with organic solvents and the lysoGb3 concentration was quantified by UPLC-ESI-MS/MS (ultraperformance liquid chromatography–electrospray ionization–tandem mass spectrometry). Calibration curves were constructed with control plasma and urine supplemented with lysoGb3. In addition to lysoGb3, lyso-ene-Gb3 was quantified. Quantification was achieved by multiple reaction monitoring of the transitions m/z 786.4 &gt; 282.3 [M+H]+ for lysoGb3, m/z 791.4 &gt; 287.3 [M+H]+ for [5,6,7,8,9] 13C5-lysoGb3, and 784.4 &gt; 280.3 [M+H]+ for lyso-ene-Gb3.

RESULTS
The mean (SD) plasma lysoGb3 concentration from 10 classically affected Fabry hemizygotes was 94.4 (25.8) pmol/mL (range 52.7–136.8 pmol/mL), from 10 classically affected Fabry heterozygotes 9.6 (5.8) pmol/mL (range 4.1–23.5 pmol/mL), and from 20 healthy controls 0.4 (0.1) pmol/mL (range 0.3–0.5 pmol/mL). Lyso-ene-Gb3 concentrations were 10%–25% of total lysoGb3. The urine concentration of lysoGb3 was 40–480 times lower than in corresponding plasma samples. Lyso-ene-Gb3 concentrations in urine were comparable or even higher than the corresponding lysoGb3 concentrations.

CONCLUSIONS
This assay for the quantification of lysoGb3 and lyso-ene-Gb3 in human plasma and urine samples will be an important tool in the diagnosis of Fabry disease and for monitoring the effect of enzyme replacement therapy in patients with Fabry disease.
Long-Term Treatment with a Health Product (Squina Diacylglyceryl Ether) Enhances Innate and Adaptive Immunity in Mice
Authors: LEUNG Hoi Yan , KO Kam Ming 
Published: December 2012

Abstract
This study aimed to investigate the effects of a health product Squina (Diacylglyceryl Ether) (DAGE) on innate and adaptive immunity in mice. Both ex vivo/ in vivo mouse models and an in vitro system using cultured mouse splenocytes were recruited for the assessment of innate and adaptive immunity. For the innate immune response, DAGE extract treatment enhanced the LPS-induced IL1-β secretion by activated macrophages in vitro and long-term DAGE treatment (0.18 and 1.8 g/kg × 20 doses) elevated the phagocytic activity of macrophages, as well as natural killer cell activity in mice. The DAGE-induced increase in macrophage phagocytic and natural killer cell activities were accompanied by the suppression of tumor growth in Sarcoma-180 cell-inoculated mice. For the adaptive immune response, long-term DAGE treatment enhanced the splenocyte index and concanavalin A- stimulated proliferation ex vivo in mice. Consistently, the incubation with DAGE extract potentiated the concanavalin A-stimulated proliferation in mouse splenocytes in vitro. In conclusion, the results show that long-term DAGE treatment produces stimulatory effects on both innate and adaptive immunity in mice.
How Do We Get Cobb-Douglas and Leontief Functions from CES Function: A Lecture Note on Discrete and Continuum Differentiated Object Models
Authors: Saito Tetsuya 
Published: December 2012

Abstract
Most lectures teach the relationship between the CES, Cobb-Douglas, and Leontief functions using the value of elasticity of substitution, namely, in the discrete object model. This lecture note aims at being a reference for algebraic computations of the Leontief and Cobb-Douglas functions by taking limits of CES functions both in discrete and continuum goods models. The argument on the discrete case uses l'H�pital's rule as usually done. The argument on the continuum case also uses l'H�pital's rule to show the convergence to the Cobb-Douglas function. To guarantee the convergence to the Leontief function, however, we rely on the squeeze principle.
On the Teaching of Price Discrimination in Block Pricing: A Refinement
Authors: Cao Bolong 
Published: December 2012

Abstract
In many textbooks, an important assumption difference between the standard picture for block pricing and the intuitive discussions on this pricing scheme is often ignored. This practice leads the students to misunderstand this picture as an illustration for price discrimination against heterogeneous buyers. In this article, I analyze how some textbook narratives can lead to this misinterpretation. Then, I provide a simple example that shows how block pricing discriminates buyers with heterogeneous demands. A real life example as applied to the transportation rates of natural gas for block pricing is also provided and discussed.
Using Experiments to Illustrate the Role of Network Externalities in Technology Adoption and Industry Evolution
Authors: Parker Wheatley W. 
Published: December 2012

Abstract
This experiment helps students to understand the importance of network externalities in technology adoption and the evolution of industries. Students observe the roles of lock-in and critical mass in technology adoption, understand how pricing affects adoption, and see welfare implications of network externalities. Given examples of network effects in firm and government action (e.g., the advanced television systems committee, antitrust litigation for the credit/debit card industry, and private strategy in newer DVD technologies (HD DVD vs. Blue-Ray)), this experiment fits courses that wish to illustrate these ideas and provides a starting point for a more detailed study of network externalities
Efficiency and Productivity of Indian Life Insurance Industry
Authors: Chakraborty Kalyan , Dutta Anirban , Sengupta Partha Pratim 
Published: December 2012

Abstract
This paper investigates technical efficiency and productivity growth in Indian life insurance industry in the era of deregulation. The empirical study uses DEA method and Malmquist productivity index to measure and decompose technical efficiency and productivity growth, respectively. The results suggest that the growth in overall productivity is mainly attributed to improvement in efficiency. Higher pure technical efficiency and lower scale efficiency indicate the insurance firms have generally, moved away from the optimal scale over the study period. The truncated regression exploring the main drivers of efficiency in the long run found claims ratio, distribution ratio, and firm-size influence technical efficiency positively. The study also found firms that had both life and non-life businesses are more efficient than firms that has only life insurance business.