bluuebunny/crossref_metadata_2025 huggingface dataset:
Improvements of insulin resistance in ovariectomized rats by a novel phytoestrogen from Curcuma comosa Roxb
Authors: Prasannarong Mujalin , Saengsirisuwan Vitoon , Piyachaturawat Pawinee , Suksamrarn Apichart
Published: March 2012

Background

Curcuma comosa Roxb. (C. comosa) is an indigenous medicinal herb that has been used in Thailand as a dietary supplement to relieve postmenopausal symptoms. Recently, a novel phytoestrogen, (3R)-1,7-diphenyl-(4E,6E)-4,6-heptadien-3-ol or compound 049, has been isolated and no study thus far has investigated the role of C. comosa in preventing metabolic alterations occurring in estrogen-deprived state. The present study investigated the long-term effects (12 weeks) of C. comosa hexane extract and compound 049 on insulin resistance in prolonged estrogen-deprived rats.

Methods

Female Sprague-Dawley rats were ovariectomized (OVX) and treated with C. comosa hexane extract (125 mg, 250 mg, or 500 mg/kg body weight (BW)) and compound 049 (50 mg/kg BW) intraperitoneally three times per week for 12 weeks. Body weight, food intake, visceral fat weight, uterine weight, serum lipid profile, glucose tolerance, insulin action on skeletal muscle glucose transport activity, and GLUT-4 protein expression were determined.

Results

Prolonged ovariectomy resulted in dyslipidemia, impaired glucose tolerance and insulin-stimulated skeletal muscle glucose transport, as compared to SHAM. Treatment with C. comosa hexane extract and compound 049, three times per week for 12 weeks, markedly reduced serum total cholesterol and low-density lipoprotein levels, improved insulin sensitivity and partially restored uterine weights in ovariectomized rats. In addition, compound 049 or high doses of C. comosa hexane extract enhanced insulin-mediated glucose uptake in skeletal muscle and increased muscle GLUT-4 protein levels.

Conclusions

Treatment with C. comosa and its diarylheptanoid derivative improved glucose and lipid metabolism in estrogen-deprived rats, supporting the traditional use of this natural phytoestrogen as a strategy for relieving insulin resistance and its related metabolic defects in postmenopausal women.
Use of the integrated health interview series: trends in medical provider utilization (1972-2008)
Authors: Davern Mike , Blewett Lynn A , Lee Brian , Boudreaux Michel , King Miriam L
Published: March 2012

The Integrated Health Interview Series (IHIS) is a public data repository that harmonizes four decades of the National Health Interview Survey (NHIS). The NHIS is the premier source of information on the health of the U.S. population. Since 1957 the survey has collected information on health behaviors, health conditions, and health care access. The long running time series of the NHIS is a powerful tool for health research. However, efforts to fully utilize its time span are obstructed by difficult documentation, unstable variable and coding definitions, and non-ignorable sample re-designs. To overcome these hurdles the IHIS, a freely available and web-accessible resource, provides harmonized NHIS data from 1969-2010. This paper describes the challenges of working with the NHIS and how the IHIS reduces such burdens. To demonstrate one potential use of the IHIS we examine utilization patterns in the U.S. from 1972-2008.
Ingesting a pre-workout supplement containing caffeine, B-vitamins, amino acids, creatine, and beta-alanine before exercise delays fatigue while improving reaction time and muscular endurance
Authors: Spradley Brandon D , Crowley Kristy R , Tai Chih-Yin , Kendall Kristina L , Fukuda David H , Esposito Enrico N , Moon Sarah E , Moon Jordan R
Published: March 2012

Background

The purpose of this study was to determine the effects of the pre-workout supplement Assault™ (MusclePharm, Denver, CO, USA) on upper and lower body muscular endurance, aerobic and anaerobic capacity, and choice reaction time in recreationally-trained males. Subjective feelings of energy, fatigue, alertness, and focus were measured to examine associations between psychological factors and human performance.

Methods

Twelve recreationally-trained males participated in a 3-week investigation (mean +/- SD, age: 28 +/- 5 y, height: 178 +/- 9 cm, weight: 79.2 +/- 15.7 kg, VO2max: 45.7 +/- 7.6 ml/kg/min). Subjects reported to the human performance laboratory on three separate occasions. All participants completed a baseline/familiarization day of testing that included a maximal graded exercise test for the determination of aerobic capacity (VO2max), one-rep maximum (1-RM) for bench and leg press to determine 75% of 1-RM, choice reaction tests, and intermittent critical velocity familiarization. Choice reaction tests included the following: single-step audio and visual, one-tower stationary protocol, two-tower lateral protocol, three-tower multi-directional protocol, and three-tower multi-directional protocol with martial arts sticks. Subjects were randomly assigned to ingest either the supplement (SUP) or the placebo (PL) during Visit 2. Subjects were provided with the cross-over treatment on the last testing visit. Testing occurred 20 min following ingestion of both treatments.

Results

Significant (p < 0.05) main effects for the SUP were observed for leg press (SUP: 13 ± 6 reps, PL: 11 ± 3 reps), perceived energy (SUP: 3.4 ± 0.9, PL: 3.1 ± 0.8), alertness (SUP: 4.0 ± 0.7, PL: 3.5 ± 0.8), focus (SUP: 4.1 ± 0.6, PL: 3.5 ± 0.8), choice reaction audio single-step (SUP: 0.92 ± 0.10 s, PL: 0.97 ± 0.11 s), choice reaction multi-direction 15 s (SUP: 1.07 ± 0.12 s, PL: 1.13 ± 0.14 s), and multi-direction for 30 s (SUP: 1.10 ± 0.11 s, PL: 1.14 ± 0.13 s).

Conclusions

Ingesting the SUP before exercise significantly improved agility choice reaction performance and lower body muscular endurance, while increasing perceived energy and reducing subjective fatigue. These findings suggest that the SUP may delay fatigue during strenuous exercise.
A synthetic biology approach to self-regulatory recombinant protein production in Escherichia coli
Authors: Dragosits Martin , Nicklas Daniel , Tagkopoulos Ilias
Published: March 2012

Background

Recombinant protein production is a process of great industrial interest, with products that range from pharmaceuticals to biofuels. Since high level production of recombinant protein imposes significant stress in the host organism, several methods have been developed over the years to optimize protein production. So far, these trial-and-error techniques have proved laborious and sensitive to process parameters, while there has been no attempt to address the problem by applying Synthetic Biology principles and methods, such as integration of standardized parts in novel synthetic circuits.

Results

We present a novel self-regulatory protein production system that couples the control of recombinant protein production with a stress-induced, negative feedback mechanism. The synthetic circuit allows the down-regulation of recombinant protein expression through a stress-induced promoter. We used E. coli as the host organism, since it is widely used in recombinant processes. Our results show that the introduction of the self-regulatory circuit increases the soluble/insoluble ratio of recombinant protein at the expense of total protein yield. To further elucidate the dynamics of the system, we developed a computational model that is in agreement with the observed experimental data, and provides insight on the interplay between protein solubility and yield.

Conclusion

Our work introduces the idea of a self-regulatory circuit for recombinant protein products, and paves the way for processes with reduced external control or monitoring needs. It demonstrates that the library of standard biological parts serves as a valuable resource for initial synthetic blocks that needs to be further refined to be successfully applied in practical problems of biotechnological significance. Finally, the development of a predictive model in conjunction with experimental validation facilitates a better understanding of the underlying dynamics and can be used as a guide to experimental design.
The 9th annual computational and systems neuroscience (cosyne) meeting
Authors: Grabska-Barwińska Agnieszka , Poo Cindy
Published: March 2012

The 9th annual Computational and Systems Neuroscience meeting (Cosyne) was held 23–26 February in Salt Lake City, Utah. Cosyne meeting is the forum for exchange of experimental and theoretical/computational approaches to studying systems neuroscience.
Notch system in the linkage of innate and adaptive immunity
Authors: Ito Toshihiro , Connett Judith M , Kunkel Steven L , Matsukawa Akihiro
Published: March 2012

Review on the role of Notch system in peripheral T cell immunity.

The lung is one of the most immunologically challenged organs and can be affected by a number of pathogens, including bacteria, virus, fungi, and parasites. The development and chronicity of pulmonary infection are determined by the early innate response to the pathogenic stimuli and are regulated at multiple levels. Initial studies have indicated that the interaction of Notch and Notch ligands plays a critical role during development, and further, the Notch system is an important bridge between APCs and T cell communication circuits. APCs are essential regulators of the innate immune response. They can respond to PAMPs through PRRs, which function in the recognition of pathogenic components and play an important role in the innate and adaptive immune response. T cells are essential regulators of adaptive immune responses and infectious diseases. However, the role of the Notch system in the cross-talk between APC and T cells during pulmonary infection is still poorly understood. In the present review, we discuss recent findings that explore the mechanisms underlying the role of Notch signaling in the linkage of innate and adaptive immunity, including pulmonary infection though PPRs and Notch activation.
The role of hair cells, cilia and ciliary motility in otolith formation in the zebrafish otic vesicle
Authors: Stooke-Vaughan Georgina A. , Huang Peng , Hammond Katherine L. , Schier Alexander F. , Whitfield Tanya T.
Published: March 2012

Otoliths are biomineralised structures required for the sensation of gravity, linear acceleration and sound in the zebrafish ear. Otolith precursor particles, initially distributed throughout the otic vesicle lumen, become tethered to the tips of hair cell kinocilia (tether cilia) at the otic vesicle poles, forming two otoliths. We have used high-speed video microscopy to investigate the role of cilia and ciliary motility in otolith formation. In wild-type ears, groups of motile cilia are present at the otic vesicle poles, surrounding the immotile tether cilia. A few motile cilia are also found on the medial wall, but most cilia (92-98%) in the otic vesicle are immotile. In mutants with defective cilia (iguana) or ciliary motility (lrrc50), otoliths are frequently ectopic, untethered or fused. Nevertheless, neither cilia nor ciliary motility are absolutely required for otolith tethering: a mutant that lacks cilia completely (MZovl) is still capable of tethering otoliths at the otic vesicle poles. In embryos with attenuated Notch signalling [mindbomb mutant or Su(H) morphant], supernumerary hair cells develop and otolith precursor particles bind to the tips of all kinocilia, or bind directly to the hair cells’ apical surface if cilia are absent [MZovl injected with a Su(H)1+2 morpholino]. However, if the first hair cells are missing (atoh1b morphant), otolith formation is severely disrupted and delayed. Our data support a model in which hair cells produce an otolith precursor-binding factor, normally localised to tether cell kinocilia. We also show that embryonic movement plays a minor role in the formation of normal otoliths.
Mario A. Mercuri 1950 - 2011
Authors: Ruggieri P.
Published: March 2012

Professor Mario Mercuri passed away suddenly after a complication of cancer on 7th May 2011 after dedicating his entire life to patients with tumours.
Second order Dehn functions of Pride groups
Authors: Davidson Peter
Published: March 2012

Under suitable conditions upper bounds of second order Dehn functions of Pride groups are obtained. From this we show that the second order Dehn function of a right-angled Artin group is at most quadratic.
Fetal sex and perinatal outcomes
Authors: Aibar Laura , Puertas Alberto , Valverde Mercedes , Carrillo M. Paz , Montoya Francisco
Published: March 2012

Objective: To evaluate the relationship of fetal sex with obstetric risk factors and perinatal outcomes.

Material and methods: Retrospective study of deliveries during 2003–2009 at a tertiary hospital based on the analysis of obstetric and neonatal risk variables according to neonatal sex.

Results: Of the 29,530 deliveries studied, the neonate was a boy in 15,038 (50.92%) and a girl in 14,492 (49.08%). The rates of gestational diabetes, prematurity, true umbilical cord knot and nuchal cord were higher for male newborns, whereas the rate of echographic diagnosis of intrauterine fetal growth retardation was higher for female newborns. Mothers of male fetuses had higher rates of cesarean delivery and instrumental vaginal delivery. The indication for ending labor due to the non-reassuring fetal heart rate was also more frequent among male newborns. This group had higher rates of acidemia, although there were no significant differences between sexes in other short-term neonatal outcomes. In all subgroups analyzed here, fetal weight was higher in male newborns.

Conclusions: Male sex is an independent risk factor for unfavorable outcomes of pregnancy and delivery.
Atomistic Simulation of Nuclear Fuels
Authors: Krack Matthias
Published: March 2012

The experimental investigation of actinide materials like nuclear fuels is difficult and usually very costly. Therefore a reliable multi-scale modeling of these often hazardous materials starting at the atomistic level is inevitable to gain further insight into this type of materials. The development of new, more advanced simulation methods accompanied by the rapid growth of the available computational resources provided by high-performance computing facilities, allows the modeling of such materials at a new quality level. Also the recent development of the CP2K program package (http://www.cp2k.org) has been partially focused on enabling state-of-the-art simulations of actinide materials using classical potential as well as electronic structure methods. The long-term goal is to perform reliable molecular dynamics simulations for actinide materials including advanced simulation techniques like nudged elastic band or metadynamics simulations. In this work, the CP2K program package and its application to the simulation of defect migration in uranium dioxide (UO2) using the nudged elastic band method is presented.
Design of Flexible Supercapacitors Using Metal Oxide-Decorated Carbon Nanotube Sheet
Authors: Sellers Meredith C.K. , Zussblatt Niels P. , Friedl Andrew P. , Marsh Charles P.
Published: March 2012

The economical production of flexible, chemically-functionalized carbon nanotube (CNT) electrodes is appealing for the manufacture of electronic textiles with integrated charge storage capability. In this paper, a commercial CNT sheet is treated with 0.02 M potassium permanganate at room temperature to accomplish in-situ deposition of manganese dioxide. The morphology, elemental oxidation states, and crystallinity of the modified CNT sheet are studied using SEM, EDX, XPS, and XRD. Manganese loading is varied from 4 to 20 weight-percent by tuning solution treatment time, and metal oxide hydration state is influenced by thermal annealing at 200 °C. Electrochemical measurements reveal that charge is stored not only via CNT-induced electrical double-layer capacitance, but also through metal oxide-mediated Faradic reactions. The MnO2-decorated CNT sheet exhibits a specific capacitance of 89.6 F/g at 1 A/g, a tenfold enhancement compared to pristine CNT sheet. Overall, this simplified processing approach holds promise for cost-effective incorporation of electrochemical capacitors into functional fabrics for energy-generation applications.
Electrochemical Oxidation of Phenol in Water Solutions Using Nanocrystalline Boron-Doped Diamond Film Anode
Authors: Lara Viera Jorge Arturo , Ram Manoj K. , Villalba Pedro , Ladanov Mikhail , Kumar Ashok
Published: March 2012

The present paper reports the utilization of a boron-doped nanocrystalline diamond film (BDD) in electrochemical oxidization (ECO) process of organic phenol compound in 0.1 M H2SO4 water solution. The nano BDD films were synthesized by microwave plasma chemical vapor deposition (MWPCVD), and then characterized by Raman spectroscopy and SEM before and after the electrochemical oxidation treatment. For the ECO treatment performed to the test sample solution, an observation of the first and the last voltammetric plots exhibited a qualitatively differences between the two plots where the first one represent the initial concentration and the last one the signal produced by the organic solution after treatment. UV-Vis analysis through the application of a standard calibration curve, quantitatively confirmed the composition of phenol remaining in the sample solution subdued to the ECO treatment.
Graphene in plastic packages: A low cost construction method for resistive chemical sensors
Authors: Kona Silpa , Harnett Cindy K
Published: March 2012

The discovery of carbon nanotubes and subsequently graphene has led to an interest in carbon materials as sensing elements due to their unique properties. Graphene is a 2-dimensional material that has a large surface area (~2630 m2g-1) that can be exposed to surface adsorbates from a target gas. This enables studies on the interaction of gas molecules with the graphene surface and resulting changes in its properties, making graphene an excellent sensing element. We present our graphene based sensor with the focus on designing small, cost effective and reliable sensors with high sensitivity towards the target gas, detailing the assembly of graphene/acrylic based devices, their characterization and investigation of their performance as resistive chemical sensors
Fabrication of SrTiO3 Nanofibers for Hydrogen Production
Authors: Macaraig Lea , Chuangchote Surawut , Sagawa Takashi
Published: March 2012

Water-splitting to form hydrogen was examined by using strontium titanate (SrTiO3) nanofibers as photocatalysts. SrTiO3 nanofibers were fabricated by hydrothermal treatment of amorphous titanium dioxide nanofibers, which were electrospun from the mixture of polyvinylpyrrolidone (PVP), titanium(IV) butoxide, and acetylacetone. The hydrothermal treatment involved the reaction of amorphous TiO2 nanofiber template with strontium hydroxide octahydrate (Sr(OH)2·8H2O) for 20 hours at 120 ºC. The product was calcined to form crystalline SrTiO3 nanofibers, which were characterized via Scanning Electron Microscopy (SEM)/Energy Dispersive Spectroscopy (EDS) and tested their photocatalytic activities for the water splitting. The hydrogen production with the fabricated SrTiO3 nanofibers was found to be 6.1 μmol·h-1·g-1 catalyst, which is twice that of commercially available SrTiO3 nanoparticles (3.0 μmol·h-1·g-1 catalyst).
Gas permeability and mechanical properties of PDMS mixed with PMPS nanofibers produced by electrospinning
Authors: Nakano Atsushi , Miki Norihisa , Hishida Koichi , Hotta Atsushi
Published: March 2012

Polymethylphenylsilicone (PMPS), a siloxane polymer with a phenyl group, was first successfully electrospun to fabricate different diameters of silicone fibers ranging from 500 nm to 10 μm by considering solubility parameters of 12 different solvents. The resulting PMPS fibers were mixed with polydimethylsiloxane (PDMS) by retaining their original nanofiber structures to produce a polysiloxane-based nanofibrous composite. As for the mechanical properties, the PMPS/PDMS composite presented higher Young’s modulus and higher fracture strain than pure PDMS. The gas permeability test revealed that the PMPS/PDMS composite exhibited higher CO2 permeability than the pure PDMS membrane. Moreover, CO2 permeability gradually increased by raising the compounding ratio of PMPS-fibers in the PMPS/PDMS composite and by decreasing the diameter of PMPS-fibers. The enhancement mechanism observed in both mechanical properties and CO2 permeability was discussed from the viewpoint of the interface between PMPS and PDMS along with the nanofiber network structures.
Multi-Frequency Atomic Force Microscopy Combining Amplitude- and Frequency-Modulation Techniques
Authors: Solares Santiago D. , Chawla Gaurav
Published: March 2012

Multi-frequency atomic force microscopy (AFM) offers additional response signals in comparison to traditional dynamic AFM. Furthermore, depending on the mode of operation used, the higher eigenmode responses are generally not directly influenced by the topographical acquisition control loops, such that they can explore a fuller range of tip-sample interactions. In this work we describe the implementation of multi-frequency imaging schemes that enable the acquisition of topographical, phase and frequency shift contrast in tapping-mode operation. This type of characterization can be especially useful for soft, highly dissipative samples, such as polymers, for which the various response channels can exhibit significantly different response, thus providing complementary information. We discuss typical results obtained as well as important challenges that need to be addressed in order to develop a fully quantitative technique.
Nanoscale Dynamic Viscoelastic Measurements at Elevated Temperature
Authors: Ye Jiping , Shimizu Satoshi
Published: March 2012

A nanoscale dynamic mechanical analysis (nano-DMA) measurement method has been successfully developed for use in evaluating nanoscale dynamic viscoelastic properties in small-scale polymer materials over a range of non-ambient temperatures from -120 oC to 500 oC. Measurements have been obtained with a nanoindentation measurement system, in which two key techniques are applied. One is a thermal protection system for control and prevention of thermal drift and noise. The other is an environmental control system for preventing corrosion at high temperatures and dew condensation at low temperatures. Measurement reliability was examined by using a combination of a thermal-mechanically stable fused silica and a homogeneous sample of isotropic polyethylene terephthalate (PET). Constant hardness and modulus values of the fused silica from -120 oC to 500 oC indicated that the measurements were not affected by thermal load drift and noise even at elevated temperatures. The PET sample exhibited no significant difference in temperature dispersions of storage elastic modulus, loss elastic modulus and loss tangent between the nanoindentation measurement data and bulk data measured with a conventional DMA method. A practical application involving surface-deteriorated polyethylene (PE) tubes was used to demonstrate the validity and usefulness of this nano-DMA method. Infrared spectroscopic imaging revealed that the surface layer of the PE tubes was oxidized to form a carbonylated (O=C<) layer. The storage elastic modulus and glass-transition temperature of the surface layer were much higher than the corresponding values of the interior. These data indicate a plausible reason for why the PE tube surface deteriorates to form brittle cracks.
Field Emission Device Made from Multiwalled Carbon Nanotube Sheet
Authors: Van Hai H. , Zhang Mei , Wang Ben , Zhang Chuck
Published: March 2012

A new type of cathode for electron field emission (FE) was fabricated. The cathode was made from ultra-thin multiwalled carbon nanotube (CNT) sheets. These sheets were drawn directly from a CNT forest, stacked layer-by-layer together and densified by isopropyl alcohol. CNT emitters were formed by utilizing laser beam to cut the sheet. The FE performance of the proposed devices has been enhanced dramatically. The threshold field for electron emission (at which the emission current is 10 mA/cm2) was 0.88 V/μm. The current density of 36 A/cm2 was achieved at the electric field of 2 V/μm. The enhanced performance is the result of the thin, uniformly distributed and aligned array of the CNT emitters.
Nonlinear Dielectric and Piezoelectric Responses in (Bi, La)FeO3-Pb(Ti, Mn)O3 Ceramics
Authors: Shi Guiyang , Bu Shundong , Dai Rui , Yu Shengwen , Cheng Jinrong
Published: March 2012

Polycrystalline solutions of 0.6(Bi0.9La0.1)FeO3-0.4Pb(Ti1-xMnx)O3(BLF-PTM, x=0 and 0.01)have been fabricated by the so-gel process combined with a solid state reaction method. BLF-PTM exhibits the nonlinear dielectric and piezoelectric responses under applied fields. Rayleigh law has been used to evaluate the irreversible contribution of the domain walls movement to the nonlinear dielectric response. Rayleigh analysis reveals that a mechanism with no associated loss exists in the BLF-PTM of x=0.01. The real part piezoelectric coefficient of BLF-PTM linearly increases with increasing the electric fields. The dielectric and piezoelectric nonlinear coefficient of 0.17×10-3 m/V and 0.897 ×10-17 m2/V2 respectively are obtained for BLF-PTM of x=0.01,which are smaller than those of 0.22×10-3 m/V and 1.19 ×10-17 m2/V2 for BLF-PTM of x=0. Our results indicate that Mn doping increase the intrinsic piezoelectric properties of BLF-PTM reducing the extrinsic contributions to piezoelectric responses.
John Rawls: a economia moral da justiça
Authors: Thiry-Cherques Hermano Roberto
Published: March 2012

Neste texto, descrevo como o filósofo norte-americano John Rawls reformulou o pensamento moral contemporâneo, ao propor a subordinação da ética à justiça. Resumo a defesa que apresentou para uma moral fundada em um pacto que compensasse, sem tentar anulá-las, as assimetrias econômico-sociais do mundo em que vivemos. Concluo com uma discussão sobre as dificuldades teóricas que encontrou para absorver o pluralismo cultural, filosófico, político e religioso do Ocidente.
Costs and usage of healthcare services before and after open bariatric surgery
Authors: Kelles Silvana Marcia Bruschi , Barreto Sandhi Maria , Guerra Henrique Leonardo
Published: March 2012

CONTEXT AND OBJECTIVE: Morbidly obese individuals are major consumers of healthcare services, with high associated costs. Bariatric surgery is an alternative for improving these individuals' comorbidities. There are no studies comparing costs before and after bariatric surgery in Brazil. The aim here was to analyze results relating to healthcare usage and direct costs among morbidly obese patients undergoing bariatric surgery. DESIGN AND SETTING: Historical cohort study on patients receiving healthcare through a private health plan in Belo Horizonte, Minas Gerais. METHODS: All healthcare services and their associated costs were included in the analysis: hospitalization, hospital stay, elective outpatient consultations, emergency service usage and examinations. The analyses were treated as total when including the whole years before and after surgery, or partial when excluding the three-month periods adjacent to the operation. RESULTS: For 382 obese patients who underwent open bariatric operations, there were 53 hospitalizations one year before and 95 one year after surgery (P = 0.013). Gastrointestinal complications were the main indications for post-procedure hospitalizations. The partial average cost almost doubled after the operation (US$ 391.96 versus US$ 678.31). In subgroup analysis, the costs from patients with gastrointestinal complications were almost four times greater after bariatric surgery. Even in the subgroup without complications, the partial average cost remained significantly higher. CONCLUSION: Although bariatric surgery is the only path towards sustained weight loss for morbidly obese patients, the direct costs over the first year after the procedure are greater. Further studies, with longer follow-up, might elucidate whether long-term reversal of this trend would occur
Abundance and extinction in Ordovician–Silurian brachiopods, Cincinnati Arch, Ohio and Kentucky
Authors: Zaffos Andrew , Holland Steven M.
Published: March 2012

A basic hypothesis in extinction theory predicts that more abundant taxa have an evolutionary advantage over less abundant taxa, which should manifest as increased survivorship during major extinction events and longer fossil-record durations. Despite this, various paleontologic studies have found conflicting patterns, indicating a more complex relationship between abundance and extinction in the geologic past. This study tests the relationship between abundance and extinction among brachiopod genera within seven third-order depositional sequences spanning the Late Ordovician to Early Silurian (Katian–Aeronian) of the Cincinnati Arch.

Contrary to predictions, abundance is not positively correlated with duration in this study. Abundance and duration range from strongly negatively correlated to uncorrelated depending on the spatial scale of analysis and the geologic intervals included, but correlations never indicate that abundance is an evolutionary advantage. In contrast, abundance was an advantageous trait prior to the Ordovician/Silurian extinction, and brachiopods with higher abundances were more likely to survive the event than less abundant brachiopods. While this result is in keeping with common models of extinction, it has not been observed previously at a mass extinction boundary. This may be further evidence that the Ordovician/Silurian extinction was not accompanied by a shift in the macroevolutionary selectivity regime.
Vision and the diversification of Phanerozoic marine invertebrates
Authors: Aberhan Martin , Nürnberg Sabine , Kiessling Wolfgang
Published: March 2012

Identifying biological traits that promote evolutionary success is fundamental for understanding biodiversity dynamics and for assessing the evolutionary response of organisms to global change. We tested the hypothesis that image-forming eyes have contributed to the diversification of taxa in the geological past. Using fossil occurrences in the Paleobiology Database, we analyzed the diversity and evolutionary rates of more than 17,000 Phanerozoic genera of marine invertebrates living on or above the shallow-water seafloor according to their visual capabilities. Analysis of the complete data set shows a peak in the proportional diversity of sighted genera early in the Phanerozoic, and their continuance at a relatively low and stable level after the Ordovician. As an explanation of this pattern we suggest that selection pressure to develop eyes rose in the Cambrian, and that behavioral constraints had a balancing effect thereafter. In contrast to the pooled data, a clade-level study of those subgroups that contain both sighted and blind genera revealed that—in trilobites, all epifaunal bivalves, pectinoid bivalves, gastropods, and echinoderms—sighted genera diversified more strongly than blind genera. This difference is controlled by significantly raised extinction rates of blind genera. These more finely resolved patterns support the hypothesis that good vision is a key trait that promoted preferential diversification.
Stonecutters Bridge, Hong Kong: design competition
Authors: Hussain Naeem , Falbe-Hansen Klaus , Gimsing Niels J. , Wong Chris K. P.
Published: March 2012

In late 1999 the Highways Department of the Government of the Hong Kong Special Administrative Region issued an open invitation to bridge designers to pre-qualify for a design competition for a road bridge across the entrance to the Kwai Chung container port. The bridge would have a span of at least 1000 m with a vertical clearance of at least 73·5 m over the full 900 m navigation channel. The purpose of the competition was to establish a reference scheme to be used as the basis for the detailed design for Stonecutters Bridge. The design competition aimed at securing a world-class design which would also be a fitting landmark and gateway for the port underlining and promoting the image of Hong Kong as a vibrant and important centre of international trade. The competition took place in early 2000 and this paper describes some of the background choosing this approach and the reasoning behind the selection of the prize-winning proposals.
Stonecutters Bridge, Hong Kong: main span erection
Authors: Ishikura Yoshihiro , Kuwabara Koji , Sham Robin , O'Grady Rory
Published: March 2012

To erect a main span of a bridge across the entrance of one of the busiest container ports in the world without causing disruption is a complex operation. Stonecutters Bridge, Hong Kong, was also the second longest cable-stayed span in the world with a unique twin box deck design that was being erected through a typhoon season. Extensive preparation works were carried out from wind tunnel tests in the UK, marine simulations, new erection procedures, typhoon studies and continuous erection analysis. The main span consisted of 53 steel segments weighing between 500 and 600 t and lifted from a purpose-built self-propelled barge. The closure of the main span posed special problems with the large deflection and expansion from a 500 m cantilever, and that the closure segment was in two pieces erected at the same time. The 224 parallel wire strand stay cables were some of the longest and heaviest cables ever erected.
Effectiveness of the traditional parameters for specifying carbonation resistance
Authors: Harrison Thomas A. , Jones Roderick , Kandasami Siva , Khanna Gaurav
Published: March 2012

This paper presents data on carbonation measurements taken from a range of test specimens stored outside but protected from rainfall. A wide range of concretes were tested that were representative of UK ready-mixed concrete production at ages of between 3·5 and 5·7 years. None of the traditional specification parameters (maximum water/cement (w/c) ratio, minimum cement content and compressive strength class) on their own or in combination give a consistent carbonation resistance. When compared at a fixed w/c ratio of 0·55, there was no clear influence of cement content on carbonation resistance. The measured carbonation depths of the Portland cement concretes were too low to show any influence of aggregate type. When extrapolated to 35 years, in a conservative manner, the data provide no grounds for concern with the BS 8500-1 recommendations with respect to carbonation resistance. There is some indication that the BS 8500-1 recommendations with respect to CEM I concretes may be too conservative. The predicted performance of concrete containing 40% or more fly ash indicates that the particular recommendations set out in BS 8500-1:2006 are justified.
Investigation on the plastic shrinkage of cementitious materials under drying conditions: mechanism and theoretical model
Authors: Liu Jia-ping , Tian Qian , Miao Chang-wen
Published: March 2012

The plastic shrinkage behaviours of fresh paste under drying conditions were investigated for several typical cementitious materials, including cement, silica fume, fly ash and calcium carbonate powder. For all four kinds of slurries, pore water under pressure (PWP) at different depths, shrinkage both in the vertical and horizontal directions, and water evaporation were measured simultaneously. Preliminary experimental investigations show an obvious anisotropic character of the plastic shrinkage behaviour in the vertical and horizontal directions and strong dependence on the PWP development. At the beginning of exposure, no PWP is generated, the total shrinkage is fully displayed by vertical displacement, and the responsible mechanism for plastic shrinkage is water evaporation. Once PWP arises, the investigated pastes exhibit vertical expansion and horizontal shrinkage; the responsible mechanism is the capillary tension in pore fluid. Based on the experimental observations, a two-phase theoretical model is proposed, which builds a quantitative relationship between water evaporation and vertical shrinkage before PWP is generated, as well as between PWP and horizontal shrinkage after PWP arises.
Phenological tracking enables positive species responses to climate change
Authors: Cleland Elsa E. , Allen Jenica M. , Crimmins Theresa M. , Dunne Jennifer A. , Pau Stephanie , Travers Steven E. , Zavaleta Erika S. , Wolkovich Elizabeth M.
Published: March 2012

Earlier spring phenology observed in many plant species in recent decades provides compelling evidence that species are already responding to the rising global temperatures associated with anthropogenic climate change. There is great variability among species, however, in their phenological sensitivity to temperature. Species that do not phenologically “track” climate change may be at a disadvantage if their growth becomes limited by missed interactions with mutualists, or a shorter growing season relative to earlier‐active competitors. Here, we set out to test the hypothesis that phenological sensitivity could be used to predict species performance in a warming climate, by synthesizing results across terrestrial warming experiments. We assembled data for 57 species across 24 studies where flowering or vegetative phenology was matched with a measure of species performance. Performance metrics included biomass, percent cover, number of flowers, or individual growth. We found that species that advanced their phenology with warming also increased their performance, whereas those that did not advance tended to decline in performance with warming. This indicates that species that cannot phenologically “track” climate may be at increased risk with future climate change, and it suggests that phenological monitoring may provide an important tool for setting future conservation priorities.
Assessment of the Reported Effectiveness of Five Different Quality-
Improvement Initiatives for the Prevention of Central Line-Associated
Bloodstream Infections in Intensive Care Units
Authors: Muscarella Lawrence F.
Published: March 2012

Five studies that evaluated five different quality-improvement initiatives for the prevention of central line-associated
bloodstream infections (CLABSIs) in adult, pediatric and/or neonatal intensive care units (ICUs) and that were published within
the past two years in an infection-control and epidemiology journal were reviewed, assessed and compared. Each is a prospective
cohort study that similarly concludes that the evaluated initiative was responsible for a significant and calculated reduction in the
CLABSI rate, ranging from 30.3% to 85%. The soundness of these conclusions and calculations, however, like the legitimacy of
several other common uses of CLABSI data, requires, in addition to satisfying a number of other criteria, that each study's
CLABSI rates be accurate and complete. The primary goal of this analysis, therefore, was to confirm the hypothesis that each of
these five studies had validated its CLABSI rates. The analysis found, however, that these five studies did not validate the
accuracy and completeness of their CLABSI rates, which raises reasonable questions about each study’s assessment of and
conclusions about the initiative's effectiveness for the prevention of CLABSIs. In addition to their aims, calculations, and
conclusions, these five studies share in common a number of features, as well as circumscribing qualities, which are discussed.
The distinction between a qualitative assessment and a quantitative determination of an initiative's performance is also discussed.
Both the circumspective use of CLABSI data that have not been validated and the cautious interpretation of conclusions about
central-line care that are based on these CLABSI data are recommended.
Risk Factors for Dialysis Withdrawal
Authors: Chan Hoi Wong , Clayton Philip A. , McDonald Stephen P. , Agar John W.M. , Jose Matthew D.
Published: March 2012

Background and objectives

Dialysis withdrawal (DW) in patients with ESRD is increasing in importance. This study assessed causes of death and risk factors for DW in Australia and New Zealand in the first year of dialysis.

Design, setting, participants, & measurements

This retrospective observational cohort study included all adult Australians and New Zealanders beginning renal replacement therapy in 1999–2008.

Results

A total of 24,884 patients with 10,073 deaths were included. Deaths from cardiac and social causes (predominantly DW) accounted for 38% and 28% of all deaths, respectively. Cumulative incidence of DW was 3.5% at 1 year (95% confidence interval [CI], 3.3%–3.8%), 9.0% at 3 years (95% CI, 8.6%–9.4%), and 13.4% at 5 years (95% CI, 12.8%–13.9%). In multivariate analysis, predictors for DW in the first year were older age (subhazard ratio [SHR], 1.70 per decade [95% CI, 1.59–1.83]; P<0.001), late referral (SHR, 1.83 [95% CI, 1.59–2.11]; P<0.001), comorbid conditions (SHR, 1.33 per each additional comorbid condition [95% CI, 1.25–1.41]; P<0.001), and diabetes (SHR, 1.16 [95% CI, 1.00–1.34]; P=0.05). Negative predictors for DW included male sex (SHR, 0.75 [95% CI, 0.66–0.87]; P<0.001), indigenous ethnicity (SHR, 0.74 [95% CI, 0.58–0.95]; P=0.02), other nonwhite race (SHR, 0.66 [95% CI, 0.48–0.91]; P=0.01), and peritoneal dialysis user (SHR, 0.59 [95% CI, 0.49–0.72]; P<0.001).

Conclusions

DW is common among dialysis patients in Australia and New Zealand. Risk factors include older age, female sex, white race, diabetes, higher comorbidity burden, hemodialysis user, and late referral to nephrologist.
Diabetes-Associated Common Genetic Variation and Its Association With GLP-1 Concentrations and Response to Exogenous GLP-1
Authors: Smushkin Galina , Sathananthan Matheni , Sathananthan Airani , Dalla Man Chiara , Micheletto Francesco , Zinsmeister Alan R. , Cobelli Claudio , Vella Adrian
Published: March 2012

The mechanisms by which common genetic variation predisposes to type 2 diabetes remain unclear. The disease-associated variants in TCF7L2 (rs7903146) and WFS1 (rs10010131) have been shown to affect response to exogenous glucagon-like peptide 1 (GLP-1), while variants in KCNQ1 (rs151290, rs2237892, and rs2237895) alter endogenous GLP-1 secretion. We set out to validate these observations using a model of GLP-1–induced insulin secretion. We studied healthy individuals using a hyperglycemic clamp and GLP-1 infusion. In addition, we measured active and total GLP-1 in response to an oral challenge in nondiabetic subjects. After genotyping the relevant single nucleotide polymorphisms, generalized linear regression models and repeated-measures ANCOVA models incorporating potential confounders, such as age and BMI, were used to assess the associations, if any, of response with genotype. These variants did not alter GLP-1 concentrations in response to oral intake. No effects on β-cell responsiveness to hyperglycemia and GLP-1 infusion were apparent. Diabetes-associated variation (T allele at rs7903146) in TCF7L2 may impair the ability of hyperglycemia to suppress glucagon (45 ± 2 vs. 47 ± 2 vs. 60 ± 5 ng/L for CC, CT, and TT, respectively, P = 0.02). In nondiabetic subjects, diabetes-associated genetic variation does not alter GLP-1 concentrations after an oral challenge or its effect on insulin secretion.
Thermodiffusion motion of electrically charged nanoparticles
Authors: Mezulis Ansis , Maiorov Mikhail , Petricenko Oksana
Published: March 2012

The present work deals with experimental studies to examine the theoretical model of thermodiffusion of electrically charged nanoparticles. Three different ionic magnetic colloid samples have been synthesized and profoundly analyzed. The theoretical model is a classical one, based on the calculation of the temperature and the electric potential distribution around nanoparticles. The discrepancy between experimental data and theory turns out not to exceed 20%. We focus on applying different approximations between calculated electrical double layer in the theoretical model and experimental determination of the surface charge density of colloidal particles. We assume this is the main reason for obtained discrepancy.
Patellofemoral Pain: Proximal, Distal, and Local Factors—2nd International Research Retreat, August 31–September 2, 2011, Ghent, Belgium
Authors: Powers Christopher M. , Bolgla Lori A. , Callaghan Michael J. , Collins Natalie , Sheehan Frances T.
Published: March 2012

Patellofemoral pain (PFP) is one of the most common lower extremity conditions seen in orthopaedic practice. The mission of the second International Patellofemoral Pain Research Retreat was to bring together scientists and clinicians from around the world who are conducting research aimed at understanding the factors that contribute to the development and, consequently, the treatment of PFP. The format of the 2.5-day retreat included 2 keynote presentations, interspersed with 6 podium and 4 poster sessions. An important element of the retreat was the development of consensus statements that summarized the state of the research in each of the 4 presentation categories. In this supplement, you will find the consensus documents from the meeting, as well as the keynote addresses, schedule, and platform and poster presentation abstracts.

J Orthop Sports Phys Ther 2012;42(6):A1–A54. doi:10.2519/jospt.2012.0301
Suggestions From the Field for Return to Sports Participation Following Anterior Cruciate Ligament Reconstruction: Soccer
Authors: Bizzini Mario , Hancock Dave , Impellizzeri Franco
Published: March 2012

Synopsis

Successful return to play remains a challenge for a soccer player after anterior cruciate ligament reconstruction. In addition to a successful surgical intervention, a soccer-specific functional rehabilitation program is essential to achieve this goal. Soccer-like elements should be incorporated in the early stages of rehabilitation to provide neuromuscular training specific to the needs of the player. Gym-based and, later, field-based drills are gradually intensified and progressed until the player demonstrates the ability to return to team practice. In addition to the recovery of basic attributes such as mobility, flexibility, strength, and agility, the surgically repaired knee must also regain soccer-specific neuromuscular control and conditioning for an effective return to sports. The individual coaching of the player by the sports physiotherapist and compliance with the training program by the player are key factors in the rehabilitation process. To minimize reinjury risk and to maximize the player's career, concepts of soccer-specific injury prevention programs should be incorporated into the training routine during and after the rehabilitation of players post-ACL reconstruction.

Level of Evidence

Therapy, level 5.
Suggestions From the Field for Return to Sports Participation Following Anterior Cruciate Ligament Reconstruction: American Football
Authors: Verstegen Mark , Falsone Susan , Orr Russell , Smith Steve
Published: March 2012

Synopsis

Returning an American football player to sport after an anterior cruciate ligament reconstruction is challenging on several fronts. First, there are approximately 15 different positions a football player could play, depending on how specifically you define the positions on the field. Each of these positions has specific demands for optimal size, strength, power, body composition, cardiovascular fitness, and movement. Understanding all of these factors is paramount to returning a football player not only to his sport but also to his specific position. Second, the chaotic, contact-rich nature of the sport requires that heavy demands be placed on the lower extremities to attenuate external contact forces from other players and from ground reaction forces associated with accelerating, decelerating, quick stops and starts, and changing direction. Finally, return to a competitive level of performance is further influenced by playing surface, shoe selection, the equipment the player wears, and various potential psychosocial factors. It is the responsibility of the clinician to provide a progressive and systematic rehabilitation program by first introducing preprogrammed movements that, once mastered, are progressed with elements of more reactive and random movement patterns. The precise nature of this systematic progression of advanced rehabilitation is key in developing return-to-play criteria and, ultimately, in readying an American football player for eventual return to sport and a particular position.

Level of Evidence

Therapy, level 5.