bluuebunny/crossref_metadata_2025 huggingface dataset:
Association between sociability and diffusion tensor imaging in BALB/cJ mice
Authors: Kim Sungheon , Pickup Stephen , Fairless Andrew H. , Ittyerah Ranjit , Dow Holly C. , Abel Ted , Brodkin Edward S. , Poptani Harish
Published: May 2011

The purpose of this study was to use high‐resolution diffusion tensor imaging (DTI) to investigate the association between DTI metrics and sociability in BALB/c inbred mice. The sociability of prepubescent (30‐day‐old) BALB/cJ mice was operationally defined as the time that the mice spent sniffing a stimulus mouse in a social choice test. High‐resolution ex vivo DTI data on 12 BALB/cJ mouse brains were acquired using a 9.4‐T vertical‐bore magnet. Regression analysis was conducted to investigate the association between DTI metrics and sociability. Significant positive regression (p < 0.001) between social sniffing time and fractional anisotropy was found in 10 regions located in the thalamic nuclei, zona incerta/substantia nigra, visual/orbital/somatosensory cortices and entorhinal cortex. In addition, significant negative regression (p < 0.001) between social sniffing time and mean diffusivity was found in five areas located in the sensory cortex, motor cortex, external capsule and amygdaloid region. In all regions showing significant regression with either the mean diffusivity or fractional anisotropy, the tertiary eigenvalue correlated negatively with the social sniffing time. This study demonstrates the feasibility of using DTI to detect brain regions associated with sociability in a mouse model system. Copyright © 2011 John Wiley & Sons, Ltd.
Lactate MRSI and DCE MRI as surrogate markers of prostate tumor aggressiveness
Authors: Yaligar J. , Thakur S. B. , Bokacheva L. , Carlin S. , Thaler H. T. , Rizwan A. , Lupu M. E. , Wang Y. , Matei C. C. , Zakian K. L. , Koutcher J. A.
Published: May 2011

Longitudinal studies of lactate MRSI and dynamic contrast‐enhanced MRI were performed at 4.7 T in two prostate tumor models grown in rats, Dunning R3327‐AT (AT) and Dunning R3327‐H (H), to determine the potential of lactate and the perfusion/permeability parameter Akep as markers of tumor aggressiveness. Subcutaneous AT (n = 12) and H (n = 6) tumors were studied at different volumes between 100 and 2900 mm3 (Groups 1–5). Lactate concentration was determined using selective multiple quantum coherence MRSI with the phantom substitution method. Tumor enhancement after the administration of gadolinium diethylenetriaminepenta‐acetic acid was analyzed using the Brix–Hoffmann model and the Akep parameter was used as a measure of tumor perfusion/permeability. Lactate was not detected in the smallest AT tumors (Group 1; 100–270 mm3). In larger AT tumors, the lactate concentration increased from 2.8 ± 1.0 mm (Group 2; 290–700 mm3) to 8.4 ± 2.9 mm (Group 3; 1000–1340 mm3) and 8.2 ± 2.2 mm (Group 4; 1380–1750 mm3), and then decreased to 5.0 ± 1.7 mm (Group 5; 1900–2500 mm3), and was consistently higher in the tumor core than in the rim. Lactate was not detected in any of the H tumors. The mean tumor Akep values decreased with increasing volume in both tumor types, but were significantly higher in H tumors. In AT tumors, the Akep values were significantly higher in the rim than in the core. Histological hypoxic and necrotic fractions in AT tumors increased with volume from 0% in Group 1 to about 20% and 30%, respectively, in Group 5. Minimal amounts of hypoxia and necrosis were found in H tumors of all sizes. Thus, the presence of lactate and heterogeneous perfusion/permeability are signatures of aggressive, metabolically deprived tumors. Copyright © 2011 John Wiley & Sons, Ltd.
Working Conditions of Occupational Therapists in Jordan
Authors: Abu Tariah Hashem Salman , Abu‐Dahab Sana M.N. , Hamed Razan T. , AlHeresh Rawan A. , Arahim Yousef Huda Abed
Published: May 2011

The purpose of this study was to investigate the working conditions and factors related to job satisfaction among Jordanian occupational therapists. A self‐administered survey consisting of several questions about the participants' jobs was developed for this study. The inclusion criteria included occupational therapists who worked in the field of occupational therapy (OT) in Jordan and who had at least six months of experience. The survey was distributed to 120 occupational therapists in different OT settings. One hundred and one occupational therapists from different hospitals, centres, schools and universities responded to the survey. Salaries of the participants were low in comparison with the salaries of the rest of healthcare practitioners in Jordan. Chi‐square analysis revealed significant relationship between participants' perceived job satisfaction and the administration of the setting, and between the choice of studying OT and the salary that the participant makes. Most occupational therapists in Jordan are young, have modest experience and work in general OT services in government‐owned facilities or paediatric centres. A sense of dissatisfaction was obvious among the participants. Further studies are needed to explore reasons of work satisfaction and dissatisfaction among occupational therapists in Jordan. Copyright © 2011 John Wiley & Sons, Ltd.
Synthesis of nonlinear optical chromophore and the preparation of attenuated total reflectance modulator
Authors: Liu Jialei , Huang Heyan , Liu Xinhou , Zhen Zhen
Published: May 2011

A new nonlinear optical chromophore with strong electron‐withdrawing acceptor and rigid–flexible dendron was synthesized. An electro‐optic (EO) attenuated total reflectance modulator was prepared to measure the EO coefficient of the films. Modification of the tricyanopyrroline chromophore with rigid–flexible dendron group provided reduction of dipole–dipole interactions and improvement of its solubility. As the chromophore loading increased, there was a great improvement on the macroscopic EO response of the polymeric materials obtained by incorporating this chromophore as a guest in amorphous polycarbonate. The largest EO coefficient was 42 pm/V at 1310 nm. Copyright © 2011 John Wiley & Sons, Ltd.
Alcohol elastomer based on superabsorbents
Authors: Tang Ziying , Wu Xiaoyang , Luo Zhisen , Tang Qunwei , Lin Jianming , Wu Jihuai
Published: May 2011

A microporous superabsorbent of poly(acrylic acid‐g‐cetyltrimethylammonium bromide) (PAA‐g‐CTAB) is synthesized by aqueous polymerization method. With the use of the superabsorbent as a host backbone, a large amount of alcohol is absorbed inside the micropores of PAA‐g‐CTAB to form an alcohol elastomer with an alcohol absorbency of 32 g/g. As a new kind of quasi‐solid‐state fuel, the alcohol elastomer is safe, low cost, and easy to use. The alcohol absorbency of the superabsorbent and the combustion properties of the alcohol elastomer can be adjusted by tuning the polymerization reaction conditions. The flame reactions in the alcohol elastomer arouse more interest for the alcohol elastomer. Copyright © 2011 John Wiley & Sons, Ltd.
Congenital cytomegalovirus infection and Wiskott–Aldrich syndrome successfully treated with unrelated cord blood transplantation
Authors: Almagor Yotam , Revel‐Vilk Shoshana , Averbuch Diana , Mechoulam Hadas , Engelhard Dan , Resnick Igor B. , Weintraub Michael , Stepensky Polina
Published: May 2011

We report a successful umbilical cord blood transplantation (UCBT) in an 8‐month male with Wiskott–Aldrich syndrome (WAS) and congenital cytomegalovirus (CMV) infection. The child presented at 3 months of age with symptomatic thrombocytopenia and CMV infection. Despite appropriate antiviral treatment no rise in the platelet count was observed. Genetic analysis confirmed the diagnosis of WAS. The clinical course was complicated by severe CMV retinitis with bilateral retinal hemorrhages and renal vasculitis. He underwent unrelated UCBT resulting in a rapid resolution of autoimmunity and thrombocytopenia. Pediatr Blood Cancer 2011; 57: 681–683. © 2011 Wiley‐Liss, Inc.
In vitro fertilization and risk of childhood leukemia in Greece and Sweden
Authors: Petridou Eleni Th , Sergentanis Theodoros N. , Panagopoulou Paraskevi , Moschovi Maria , Polychronopoulou Sophia , Baka Margarita , Pourtsidis Apostolos , Athanassiadou Fani , Kalmanti Maria , Sidi Vasiliki , Dessypris Nick , Frangakis Constantine , Matsoukis Ioannis L. , Stefanadis Christodoulos , Skalkidou Alkistis , Stephansson Olof , Adami Hans‐Olov , Kieler Helle
Published: May 2011

Background

Cancer risk in children born after in vitro fertilization (IVF) remains largely unknown. We aimed to investigate risk of leukemia and lymphoma following IVF using two nationwide datasets.

Methods

The hospital‐based case–control study in Greece derived from the National Registry for Childhood Hematological Malignancies (1996–2008, 814 leukemia and 277 lymphoma incident cases with their 1:1 matched controls). The Swedish case–control study was nested in the Swedish Medical Birth Register (MBR) (1995–2007, 520 leukemia and 71 lymphoma cases with their 5,200 and 710 matched controls) with ascertainment of incident cancer cases in the National Cancer Register. Study‐specific and combined odds ratios (OR) were estimated using conditional logistic regression, with adjustment for possible risk factors.

Results

Nationwide studies pointed to similar size excess risk of leukemia following IVF, but to a null association between IVF and lymphoma. The proportion of leukemia cases conceived through IVF was 3% in Greece and 2.7% in Sweden; prevalence of IVF in matched controls was 1.8% and 1.6%, respectively. In combined multivariable analyses, the increased risk of leukemia was confined to age below 3.8 years (OR = 2.21; 95% confidence interval, CI: 1.27–3.85) and to acute lymphoblastic leukemia (ALL) (OR = 1.77; 95% CI: 1.06–2.95) with no sufficient evidence of excess risk for other leukemias (OR = 1.34; 95% CI: 0.38–4.69). Following IVF, OR for ALL was 2.58 (95% CI: 1.37–4.84) before age 3.8 and 4.29 (95% CI: 1.49–12.37) before age 2 years.

Conclusions

IVF seems to be associated with increased risk of early onset ALL in the offspring. Pediatr Blood Cancer 2012; 58: 930–936. © 2011 Wiley Periodicals, Inc.
Study on the viscosity of polypropylene composites filled with different size and size distribution CaCO3
Authors: Zhang Jun , Fang Jue , Wu Jun‐Li , Wu Juan , Mo Hong , Ma Zhen‐Mao , Zhou Ning‐Lin , Shen Jian
Published: May 2011

Two kinds of different size calcium carbonates are blended and filled into polypropylene in 30 wt%. The melting viscosity of PP composites samples is measured by capillary extrusion rheometer at 230°C. The results show that the melt viscosity of PP composites evidently decreased when that was filled with the blending 325 and 1,500 mesh CaCO3 and the 1,500 mesh proportion in fillers was from 20 to 60 wt%. The viscosity in the low shear velocity decreased more than that in the high shear velocity. The shear viscosity of single filler and filler samples with the size distribution at the different temperature was studied by capillary extrusion rheometer. The results show that the flow activation energy and the flow activation entropy of composites filled with the size distribution filler increased. The change of the flow activation entropy and the model of the efficient arrangement of the structure are used to explain the phenomenon in melting viscosity decrease of PP filled with the size distribution fillers. A structural model of composites that filled with the size distribution fillers was set up. POLYM. COMPOS., 2011. © 2011 Society of Plastics Engineers
A New Method for the Simultaneous Analysis of Strychnine and Brucine in Strychnos nux‐vomica Unprocessed and Processed Seeds Using a Carbon‐paste Electrode Modified with Multi‐walled Carbon Nanotubes
Authors: Behpour Mohsen , Ghoreishi Sayed Mehdi , Khayatkashani Maryam , Motaghedifard Mohamadhasan
Published: May 2011

Introduction

Strychnos nux‐vomica L. (Loganiaceae), widely used in folk medicine, is grown extensively in southern Asian countries. Its major bioactive constituents are strychnine and brucine, which are frequently used in traditional herbal medicines for treatment of nervous diseases, vomiting and traumatic pain.

Objective

A new method using a carbon‐paste electrode modified with multi‐walled carbon nanotubes (CNT/CPE) was developed and validated for single or simultaneous determination of strychnine and brucine in Strychnos nux‐vomica seeds. Additionally, an environmentally friendly method was successfully applied to reduce the levels of strychnine and brucine in seeds.

Materials and methods

Cyclic voltammetry, chronocoulometry and differential pulse voltammetry were used with multi‐walled carbon nanotube modified carbon‐paste electrodes.

Results

The peak currents increase linearly with the strychnine and brucine concentrations in the ranges of 50–1000 and 5–355 µ m, and the detection limits for strychnine and brucine were 0.43 and 0.28 µ m, respectively. Of the processing methods used, the greatest reduction in the strychnine and brucine levels was observed in samples processed using milk and saltwater.

Conclusion

A new, sensitive and selective method was developed for the measurement of strychnine and brucine. This method was successfully applied to the determination of strychnine and brucine in unprocessed and processed Strychnos nux‐vomica seed. Copyright © 2011 John Wiley & Sons, Ltd.
Effect of High Relative Humidity on Dried Plantago lanceolata L. Leaves during Long‐term Storage: Effects on Chemical Composition, Colour and Microbiological Quality
Authors: Gonda Sándor , Tóth László , Gyémánt Gyöngyi , Braun Mihály , Emri Tamás , Vasas Gábor
Published: May 2011

Introduction

Modern phytotherapy and quality assurance requires stability data on bioactive metabolites to identify and minimise decomposing factors during processing and storage. A compound's stability in a complex matrix can be different from the stability of the purified compound.

Objective

To test the stability of iridoids and acteoside and quantify changes in colour and microbiological quality in a common herbal tea, dried P. lanceolata leaves during exposure to high‐humidity air. To test the contribution of fungi to metabolite decomposition.

Methodology

Dried P. lanceolata leaves were exposed to atmospheres of different relative humidity (75, 45 and 0%) for 24 weeks. Changes in aucubin and catalpol concentration were determined by CE‐MEKC, and those in acteoside on TLC. Colour and chlorophyll‐like pigments were measured by different spectrophotometric methods. The number of fungi was monitored; 10 strains were isolated from the plant drug, and their ability to decompose the analytes of interest was tested.

Results

During incubation at 75% relative humidity (RH), aucubin, catalpol and acteoside concentrations decreased by 95.7, 97.0 and 70.5%, respectively. Strong shifts were detected in CIELAB parameters a* and b* (browning) as a result of conversion of chlorophyll to pheophytin. Intensive microbial proliferation was also observed. Changes at 45 or 0% RH were typically insignificant. Seven of the 10 isolated fungal strains could decompose both iridoids, and five could decompose acteoside in vitro.

Conclusion

It was shown that exposure to water results in loss of bioactive molecules of P. lanceolata dried leaves, and that colonising fungi are the key contributors to this loss. Copyright © 2011 John Wiley & Sons, Ltd.
Peroxide cured natural rubber/fluoroelastomer/high‐density polyethylene via dynamic vulcanization
Authors: Yamoun Chamaiporn , Magaraphan Rathanawan
Published: May 2011

In this work, blends of fluoroelastomer (FKM), natural rubber (NR) along with high‐density polyethylene (HDPE) by dynamic vulcanization using peroxide (DBPH, DCP) as a curing agent were prepared. HDPE was melt‐mixed with NR and FKM at different compositions (HDPE/FKM/NR i.e. 30/60/10, 30/55/15, 30/50/20, and 30/35/35%wt) using an internal mixer at 150°C and 50 rpm rotor speed. The mechanical properties and oil swelling resistances of these blends were analyzed according to ISO 37 (Type 1) and ASTM D471, respectively. The results suggest that DBPH works better as a curing agent for the dynamic vulcanization system than DCP. The optimum mechanical properties and oil resistance were revealed in 30/50/20 and 30/60/10 HDPE/FKM/NR, being dynamic vulcanized with DBPH, respectively. In addition, was found that a dispersed HDPE phase shows the percent crystallinity in the range of 53% to 55% upon increasing the NR content. The SEM micrographs reveal the NR phase is well dispersed in FKM as small particles. POLYM. ENG. SCI., 2011. © 2011 Society of Plastics Engineers .
Copolymerization of propylene with 1‐octene catalyzed by MgCl2/TiCl4/diether catalyst
Authors: Bi Fuyong , He Aihua , Li Huayi , Hu Youliang , He Zhiyuan , Han Charles C
Published: May 2011

MgCl2/TiCl4/diether is a fifth‐generation Ziegler–Natta catalyst for the commercial polymerization of propylene. The outstanding features of this catalyst are the high activity and high isotacticity for propylene polymerization without using an external electron donor. In this study, we explored the copolymerization of propylene and 1‐octene with MgCl2/TiCl4/diether catalyst. It was found that MgCl2/TiCl4/diether catalyst showed higher polymerization activity and led to greater 1‐octene content incorporation, compared with a fourth‐generation Ziegler–Natta catalyst (MgCl2/TiCl4/diester). With an increase in 1‐octene incorporation in polypropylene chains, the melting temperature, glass transition temperature and crystallinity of the copolymers decreased distinctly. The microstructures of the copolymers were characterized using 13C NMR spectroscopy, and the copolymer compositions and number‐average sequence lengths were calculated from the dyad concentration and distribution. This result is very important for the in‐reactor polyolefin alloying process, especially for the case of a single catalyst and two‐step (or two‐reactor) process. Copyright © 2011 Society of Chemical Industry
The Criticality of Transferable Skills Development and Virtual Learning Environments Used in the Teaching of Project Management
Authors: Ojiako Udechukwu , Ashleigh Melanie , Wang Jaw-Kai , Chipulu Max
Published: May 2011

Studies have found the development of transferable skills and the provision of virtual learning environments (VLEs) to be crucial to students who are learning project management. Taking these factors into consideration, this article explores why project management students have emphasized the importance of these two critical learning and teaching parameters in their developmental needs. The study was conducted utilizing focus groups consisting of 88 students in a UK higher education institution. Overall, we found the existence of five critical and applied themes grouped against transferable skills and the provision of VLEs under which students’ needs could be classified.
Detonation Wave Propagation in Double‐layer Cylindrical High Explosive Charges
Authors: Zhang Xian‐feng , Huang Zheng‐xiang , Qiao Liang
Published: May 2011

The flow fields associated with regular and irregular reflections of detonation waves in double‐layer cylindrical (DLC) high explosives (HE) are analyzed, and an analytical model for predicting the detonation wave configurations is proposed. Regular reflection and three‐shock Mach reflection during detonation wave propagation are discussed. Calculated results of pressure, flow velocity, and specific volume are presented and the Mach stem height is also determined based on mass conservation. The corresponding numerical simulation based on the Lee–Tarver model is developed to generate data comparable with an ordinary cylindrical charge. It is shown that steady convergent detonation wave propagation occurs in the DLC charge. The maximum pressure up to 4.0 times of Chapman–Jouguet (CJ) pressure is reached at the collision point related to the Mach reflection, and the predictions based on the proposed model correlate well with corresponding numerical results.
Growth variation among Bacillus thuringiensis strains can affect screening procedures for supernatant‐secreted toxins against insect pests
Authors: Argôlo Filho Ronaldo C , Gomes Rafael A , Barreto Marliton R , de P Lana UG , Valicente Fernando H , Loguercio Leandro L
Published: May 2011

BACKGROUND: Supernatant‐secreted proteins in Bacillus thuringiensis (Berliner) (Bt) with insecticidal activity provide an important source of information for discovery of new useful strains and/or entomotoxins. However, physiological variation among isolates might interfere in the detection efficiency of screening procedures on Bt collections. The aim of this study was to assess the magnitude of this variation in a sample of isolates from a tropical Bt collection, which was gauged through the assessment of their temporal patterns of growth and protein secretion in culture supernatants (SNs), as well as of the corresponding toxicity against fall armyworm (Spodoptera frugiperda, JE Smith). Feeding bioassays were performed, with larvae being treated with heated and non‐heated total protein extracted from SNs collected at different culture times. Larva mortality and reduction in pupa formation were observed.

RESULTS: Intra‐ and interisolate variations were observed in the temporal patterns of growth, quality and quantity of protein secreted, as well as in insecticidal activity of these SNs, based on larvae mortality and pupation rates. These results suggest that the insecticidal potential of certain isolates can be hidden if comparisons are done on the basis of the same number of cells in the culture and/or the same culturing time.

CONCLUSIONS: Methods of screening Bt collections on the basis of feeding bioassays can be misleading with regards to identifying more promising isolates for biocontrol purposes if physiological differences are not considered. The consequences and implications of these findings for the development of experimental systems that depend on toxicity bioassays to identify alternative Bt strains and entomotoxins with practical applicability have been discussed. Copyright © 2011 Society of Chemical Industry
Effect of Mn doping on the magnetic properties of the post‐annealed Fe48Pt52‐C composite films
Authors: Mi W. B. , Jin J. , Bai H. L.
Published: May 2011

(Fe48Pt52)1–xMnx‐C composite films with differentxwere fabricated using magnetron sputtering and post‐annealing at 550 °C. Proper Mn doping can improve the ordering of the face‐centered tetragonal (fct) FePt grains. The lattice constant ratio (c/a) first decreases, then increases with the increasingx. Atx = 2.1%, the minimumc/aof 0.964 and the maximum ordering degree of 0.96 were obtained. All of the films are hard ferromagnetic. The maximum room‐temperature coercivity of the films is 7.5 kOe atx = 2.1% and 10‐kOe field, and the coercivity decreases from 13.3 kOe at 20 K to 10.1 kOe at 300 K under a 90‐kOe field. The reversal mechanism of the films is the coexistence of the domain wall motion and Stoner–Wolhfarth (S‐W) rotation modes.
Optimal tracking performance of MIMO discrete‐time systems with communication constraints
Authors: Guan Zhi‐Hong , Zhan Xi‐Sheng , Feng Gang
Published: May 2011

The optimal tracking problem for multiple‐input multiple‐output linear‐time‐invariant discrete‐time systems with communication constraints in the feedback path is studied in this paper. The tracking performance is measured by the energy of the error signal between the output of the plant and the reference signal. The objective is to obtain an optimal tracking performance, attainable by all possible stabilizing compensators. It is shown that the optimal tracking performance consists of two parts, one depends on the nonminimum phase zeros and zero direction of the given plant, as well as the reference input signal direction, and the other depends on the nonminimum phase zeros, unstable poles, and pole direction of the given plant, as well as the bandwidth and additive white Gaussian noise of the communication channel. It is also shown that, if the constraint of the communication channel does not exist, the optimal tracking performance reduces to the existing tracking performance of the control system without communication constraints. A typical example is given to illustrate the theoretical results. Copyright © 2011 John Wiley & Sons, Ltd.
Robust multi‐drug therapy design and application to insulin resistance in type 2 diabetes
Authors: Luni Camilla , Doyle III Francis J.
Published: May 2011

Single‐drug therapies often fail in the treatment of complex diseases, such as diabetes, because they act on a specific target, and are often by‐passed by the redundant mechanisms that confer robustness to biological systems, both in health and in disease. On the other hand, multi‐drug therapies (MDTs) show greater efficacy, but efficient methodologies for their design are needed to handle the high number of combinatorial possibilities.

In this paper, we describe a methodology for MDT design based on the structured singular value, a tool from the robust control theory. The procedure can be applied to a mathematical model of the biological system under consideration, and it includes medical performance robustness as a design requirement. This aspect is of primary importance because robustness has been recognized as an intrinsic property of biological systems that maintain performance despite a variety of environmental conditions and the subject‐to‐subject variability of response. Furthermore, the development of a mathematical model always includes a certain level of uncertainty, due to the inevitable assumptions involved in its development, and the often scarce availability of experimental data.

The methodology is here applied to the insulin resistance condition, a primary impairment in the development of type 2 diabetes. Results from simulations confirm that the performance and robustness objectives are achieved under different input dynamics, and suggest potentially powerful therapeutic vector targets. Copyright © 2011 John Wiley & Sons, Ltd.
Tube‐based robust nonlinear model predictive control
Authors: Mayne D. Q. , Kerrigan E. C. , van Wyk E. J. , Falugi P.
Published: May 2011

This paper extends tube‐based model predictive control of linear systems to achieve robust control of nonlinear systems subject to additive disturbances. A central or reference trajectory is determined by solving a nominal optimal control problem. The local linear controller, employed in tube‐based robust control of linear systems, is replaced by an ancillary model predictive controller that forces the trajectories of the disturbed system to lie in a tube whose center is the reference trajectory thereby enabling robust control of uncertain nonlinear systems to be achieved. Copyright © 2011 John Wiley & Sons, Ltd.
The use of restricted mean survival time to estimate the treatment effect in randomized clinical trials when the proportional hazards assumption is in doubt
Authors: Royston Patrick , Parmar Mahesh K. B.
Published: May 2011

In most randomized clinical trials (RCTs) with a right‐censored time‐to‐event outcome, the hazard ratio is taken as an appropriate measure of the effectiveness of a new treatment compared with a standard‐of‐care or control treatment. However, it has long been known that the hazard ratio is valid only under the proportional hazards (PH) assumption. This assumption is formally checked only rarely. Some recent trials, particularly the IPASS trial in lung cancer and the ICON7 trial in ovarian cancer, have alerted researchers to the possibility of gross non‐PH, raising the critical question of how such data should be analyzed. Here, we propose the use of the restricted mean survival time at a prespecified, fixed time point as a useful general measure to report the difference between two survival curves. We describe different methods of estimating it and we illustrate its application to three RCTs in cancer. The examples are graded from a trial in kidney cancer in which there is no evidence of non‐PH, to IPASS, where the opposite is clearly the case. We propose a simple, general scheme for the analysis of data from such RCTs. Key elements of our approach are Andersen's method of ‘pseudo‐observations,’ which is based on the Kaplan–Meier estimate of the survival function, and Royston and Parmar's class of flexible parametric survival models, which may be used for analyzing data in the presence or in the absence of PH of the treatment effect. Copyright © 2011 John Wiley & Sons, Ltd.
Neural and BOLD responses across the brain
Authors: Goense Jozien , Whittingstall Kevin , Logothetis Nikos K.
Published: May 2011

Functional Magnetic Resonance Imaging (fMRI) has quickly grown into one of the most important tools for studying brain function, especially in humans. Despite its prevalence, we still do not have a clear picture of what exactly the blood oxygenation level dependent (BOLD) signal represents or how it compares to the signals obtained with other methods (e.g., electrophysiology). We particularly refer to single neuron recordings and electroencephalography when we mention ‘electrophysiological methods’, given that these methods have been used for more than 50 years, and have formed the basis of much of our current understanding of brain function. Brain function involves the coordinated activity of many different areas and many different cell types that can participate in an enormous variety of processes (neural firing, inhibitory and excitatory synaptic activity, neuromodulation, oscillatory activity, etc.). Of these cells and processes, only a subset is sampled with electrophysiological techniques, and their contribution to the recorded signals is not exactly known. Functional imaging signals are driven by the metabolic needs of the active cells, and are most likely also biased toward certain cell types and certain neural processes, although we know even less about which processes actually drive the hemodynamic response. This article discusses the current status on the interpretation of the BOLD signal and how it relates to neural activity measured with electrophysiological techniques. WIREs Cogn Sci 2012, 3:75–86. doi: 10.1002/wcs.153

This article is categorized under:

Neuroscience > Physiology
Unraveling DNA dynamics using atomic force microscopy
Authors: Suzuki Yuki , Yoshikawa Yuko , Yoshimura Shige H. , Yoshikawa Kenichi , Takeyasu Kunio
Published: May 2011

The elucidation of structure–function relationships of biological samples has become important issue in post‐genomic researches. In order to unveil the molecular mechanisms controlling gene regulations, it is essential to understand the interplay between fundamental DNA properties and the dynamics of the entire molecule. The wide range of applicability of atomic force microscopy (AFM) has allowed us to extract physicochemical properties of DNA and DNA–protein complexes, as well as to determine their topographical information. Here, we review how AFM techniques have been utilized to study DNA and DNA–protein complexes and what types of analyses have accelerated the understanding of the DNA dynamics. We begin by illustrating the application of AFM to investigate the fundamental feature of DNA molecules; topological transition of DNA, length dependent properties of DNA molecules, flexibility of double‐stranded DNA, and capability of the formation of non‐Watson–Crick base pairing. These properties of DNA are critical for the DNA folding and enzymatic reactions. The technical advancement in the time‐resolution of AFM and sample preparation methods enabled visual analysis of DNA–protein interactions at sub‐second time region. DNA tension‐dependent enzymatic reaction and DNA looping dynamics by restriction enzymes were examined at a nanoscale in physiological environments. Contribution of physical properties of DNA to dynamics of nucleosomes and transition of the higher‐order structure of reconstituted chromatin are also reviewed. WIREs Nanomed Nanobiotechnol 2011 3 574–588 DOI: 10.1002/wnan.150

This article is categorized under:

Nanotechnology Approaches to Biology > Nanoscale Systems in Biology
A Systematic Review of Outcomes of Toe-to-Thumb Transfers for Isolated Traumatic Thumb Amputation
Authors: Lin Pao-Yuan , Sebastin Sandeep Jacob , Ono Shimpei , Bellfi Lillian T. , Chang Kate Wan-Chu , Chung Kevin C.
Published: May 2011

Background

Toe-to-thumb transfer is an established procedure for reconstruction of traumatic thumb amputations. The four types of toe-to-thumb transfers are the second toe, the great toe, the wrap-around great toe and the trimmed great toe transfers. The purpose of this study is to conduct a systematic review of the literature to compare outcomes amongst different methods of toe-to-thumb transfers.

Methods

A literature search using ‘toe-to-thumb transfer’ combined with ‘thumb injury’ and ‘thumb reconstruction’ as keywords and limited to humans and the English language identified 633 studies. Studies were included in the review if they: (1) present primary data, (2) report three or more toe-to-thumb transfers for isolated complete traumatic thumb amputation between the metacarpophalangeal joint and the interphalangeal joint (both excluded) and (3) present functional outcome data.

Results

Twenty-five studies representing 450 toe-to-thumb transfers met the inclusion criteria. They included 101 second toe transfers, 196 great toe transfers, 122 wrap-around transfers and 31 trimmed toe transfers. The mean survival rate was 96.4%. No statistically significant differences could be detected between the four transfers with regards to survival, arc of motion, total active motion, grip and pinch strength and static two-point discrimination.

Conclusions

All four types of toe transfer procedures have predictably high survival rates and good patient satisfaction scores. The current data are inadequate to make any comments with regards to donor site morbidity. Till such data are available, an evidence-based recommendation for the superiority of a specific type of toe-to-thumb transfer cannot be made.
The sources of basic magmatism in Western Transbaikalia in the Late Paleozoic (from geochemical and isotope data)
Authors: Badmatsyrenova R.A. , Badmatsyrenov M.V.
Published: May 2011

The studied massifs in Western Transbaikalia (Arsentyev and Orongoi) are composed of pyroxenites, high-Ti subalkalic gabbro, gabbro-diorites, monzodiorites, anorthosites, and syenites. The Orongoi massif also includes small olivinite and plagioperidotite bodies. The gabbroids have high contents of Sr, Ba, Nb, Ta, Zr, and Hf, which is typical of intraplate basites. The REE pattern shows the rock enrichment in LREE (La/YbN = 5.35–25.82). The 87Sr/86Sr values vary from 0.7050 to 0.7054, and εNd, from 1.44 to –1.18. The presence of radiogenic Nd in the gabbroids and their enrichment in 87Sr suggest their formation as a result of the melting of the EM-II-type lithospheric mantle.
The first terrace above the Ob’ floodplain near Kolpashevo: the age and formation conditions
Authors: Leshchinskiy S.V. , Blyakharchuk T.A. , Vvedenskaya I.A. , Orlova L.A.
Published: May 2011

The subaqueous sediments of the first terrace above the Ob’ River floodplain near the town of Kolpashevo are referred to as the Sartan cryochron. New data show that they formed mainly in the Early and Middle Holocene. The key section is on the right bank of the Novoil’inskaya Staritsa—a branch of the Ob’ River 10 km south of Kolpashevo. Radiocarbon dating of the peat at the terrace base yielded an age of 10,200 ± 55 years, which is close to the Pleistocene–Holocene boundary. The studied sample from the middle section has a 14C age of 5870 ± 55 years corresponding to the Atlantic Holocene optimum. The palynological data confirm the geologic structure of the section: The recognized spore-pollen spectra distinctly mark the first half of the Holocene and reflect the landscape changes. The results obtained help to refine stratigraphic charts and maps of Quaternary deposits and reconstruct the landscapes (including geochemical ones) and lithologo-facies and neotectonic conditions.
Modelling nonlinear thermoacoustic instability in an electrically heated Rijke tube
Authors: MARIAPPAN SATHESH , SUJITH R. I.
Published: May 2011

An analysis of thermoacoustic instability is performed for a horizontal Rijke tube with an electrical resistance heater as the heat source. The governing equations for this fluid flow become stiff and are difficult to solve by the computational fluid dynamics (CFD) technique, as the Mach number of the steady flow and the thickness of the heat source (compared to the acoustic wavelength) are small. Therefore, an asymptotic analysis is performed in the limit of small Mach number and compact heat source to eliminate the above stiffness problem. The unknown variables are expanded in powers of Mach number. Two systems of governing equations are obtained: one for the acoustic field and the other for the unsteady flow field in the hydrodynamic zone around the heater. In this analysis, the coupling between the acoustic field and the unsteady heat release rate from the heater appears from the asymptotic analysis. Furthermore, a non-trivial additional term, referred to as the global-acceleration term, appears in the momentum equation of the hydrodynamic zone, which has serious consequences for the stability of the system. This term can be interpreted as a pressure gradient applied from the acoustic onto the hydrodynamic zone. The asymptotic stability of the system with the variation of system parameters is presented using the bifurcation diagram. Numerical simulations are performed using the Galerkin technique for the acoustic zone and CFD techniques for the hydrodynamic zone. The results confirm the importance of the global-acceleration term. Bifurcation diagrams obtained from the simulations with and without the above term are different. Acoustic streaming is shown to occur during the limit cycle and its effect on the unsteady heat release rate is discussed.
A review of lessons learned from a Local Conservation Group approach in Indochina
Authors: Pilgrim John D. , Eberhardt Karin , Eames Jonathan C. , Vorsak Bou , Anh Pham Tuan
Published: May 2011

Building local civil society constituencies for conservation is a particularly high priority in Indochina given the regional prevalence of weak and highly-centralized government institutions with an inability or lack of will to enforce protection on the ground. BirdLife International has developed and piloted a small-scale, community-based Local Conservation Group approach to site-based conservation globally. In Indochina a number of important lessons have been learned, particularly related to the need for participatory project and activity planning, increased attention to provision of tangible benefits that clearly meet both conservation and development objectives and are tailored to heterogeneous communities, increased support for awareness-raising activities, clear monitoring of activities and impacts, and truly committed partner support for implementation.
Comparison of emperor penguin declines between Pointe Géologie and Haswell Island over the past 50 years
Authors: Barbraud Christophe , Gavrilo Maria , Mizin Yuri , Weimerskirch Henri
Published: May 2011

The emperor penguin (Aptenodytes forsteri) is highly dependent on sea ice conditions, and future climate change may affect its distribution and numbers. Most studies on the demography and population dynamics of emperor penguins in relation to sea ice characteristics were conducted at a single colony (Pointe Géologie). Several non-exclusive hypotheses have been proposed to explain the dramatic decline of this colony, including changes in sea ice conditions, predation, flipper banding and human disturbance. Here, we report and analyse updated long-term trends in numbers of breeding pairs made at two colonies (Pointe Géologie and Haswell Island) where counts are comparable. Similar changes were observed for both colonies and paralleled changes in sea ice extent. At Pointe Géologie and Haswell Island, populations declined similarly and later growth rates were also similar since the early 1990s for Haswell and early 1980s for Pointe Géologie. The magnitude of the decline was similar between both colonies when numbers of breeding pairs were assessed. This study suggests that a common large-scale environmental factor has probably negatively affected both colonies.
Archaeal diversity revealed in Antarctic sea ice
Authors: Cowie Rebecca O.M. , Maas Elizabeth W. , Ryan Ken G.
Published: May 2011

Archaea, once thought to be only extremophiles, are now known to be abundant in most environments. They can predominate in microbial communities and be significantly involved in many global biogeochemical cycles. However, Archaea have not been reported in Antarctic sea ice. Our understanding of the ecology of Antarctic sea ice prokaryotes is still in its infancy but this information is important if we are to understand their diversity, adaptations and biogeochemical roles in Antarctic systems. We detected Archaea in sea ice at two sampling sites taken from three subsequent years using conserved 16S rRNA gene archaeal primers and PCR. Archaeal abundance was measured using quantitative PCR and community diversity was investigated by sequencing cloned 16S rRNA gene PCR products. Archaea in Antarctic sea ice were found to be in low abundance consisting of ≤ 6.6% of the prokaryotic community. The majority, 90.8% of the sequences, clustered with the recently described phylumThaumarchaeota, one group closely clustered with the ammonia-oxidizing CandidatusNitrosopumilus maritimus. The remainder of the clones grouped with theEuryarchaeota.
Diagnosis and management of haematological malignancies in older people
Authors: Marr Helen , Jones Gail L , Jackson Graham H , Osborne Wendy
Published: May 2011

The incidence of most haematological malignancies increases with age. Given that those aged >65 years represent the fastest growing segment of Western populations, these cancers may commonly present to medical teams with an interest in older patients. Over the last 20 years there have been dramatic improvements in the outlook for patients diagnosed with haematological cancers, but there is evidence that many of these improvements have been restricted to younger patients. It is therefore important that older patients with haematological malignancies are rapidly diagnosed and promptly treated with the best available therapies. Clinical trials that specifically encompass older patients are clearly important. In this review, the presentation and management of common haematological malignancies will be discussed, including myelodysplasia, acute leukaemia, lymphoproliferative disorders and myeloma.
Is targeting beta-amyloid pathology, with immunotherapy, an effective treatment option for Alzheimer's disease?
Authors: O'Donovan James
Published: May 2011

Alzheimer's disease (AD) is the commonest form of dementia, estimated to affect 37 million people worldwide. Currently there is nothing to halt the progression of AD – treatment focuses largely on slowing the development of symptoms. More recently disease-modifying interventions, such as immunotherapy, have been investigated as their aim is to halt or even reverse symptoms by removing β-amyloid (Aβ) pathology. This paper assesses the developments made in this particular field, offers critical appraisal of important papers and assesses the viability of this potential form of treatment.
(A2) Strategies to Recover the Health Care Capacity Post Earthquake in Chile
Authors: Bambaren C.
Published: May 2011

Background

The earthquake that struck Chile on February 27th, 2010 produced profound damage of hospital services with 4249 bed lost especially in the regions of Maule and Bio. The capacity of the health was critically reduced in ability to assure health access to affected people by the disaster.

Discussion of Interventions

The first strategy to maintain health services was the deployment of 18 field hospitals from Chilean organizations (Army and Air Force), international organizations and foreign governments. This measure allowed for 533 beds and 16 surgical blocks in the first weeks. There were 14 field hospitals until November. Taking into account the beginning of the winter season, the national government set up another sort of strategy to increase the capacity of the health care facilities: § Strengthening of hospitals without damage that were close to the disaster area. These hospitals were used as referral centers. § Purchasing of 708 beds from the private health sector. § Habilitation of free spaces to be used for inpatients. § Increasing the capacity of home care health programs to release beds. § Construction of some small temporary units to admit patients. § Small-scale interventions to repair damages in hospitals. § Extending the work time until 16 hours in the primary health care facilities. § Improving of the efficient of the using of human and physical resources. § Restructuration of the hospital network that allowed adding 300 new beds.

Results

The ministry of health recovered more than 94% of loss beds and 92% of surgical blocks through July. However, it is necessary to identify US$ 2720 million for reconstruction program and to establish a national strategy of safe hospitals in order to reduce the future costs of the recovery of damaged health care facilities. *Based on information from PAHO – Chile.
(A4) Emergency Health Interventions in Earthquakes: Red Cross Experience from Haiti and Chile, 2010
Authors: Saaristo P. , Aloudat T.
Published: May 2011

On 12 January 2010, the fate of Haiti and its people shifted with the ground beneath them as the strongest earthquake in 200 years, and a series of powerful aftershocks demolished the capital and multiple areas throughout the southern coast in thirty seconds, leaving some 220,000 people dead, and 300,000 persons injured. On 27 February 2010, at 03:35 hours local time, an earthquake of magnitude 8.8 struck Chile. As a consequence, the tsunami generated affected a coastal strip of more than 500 kilometers. Approximately 1.5 million people were affected and thousands lost their homes and livelihoods. The emergency health response of the International Red Cross Movement to both disasters was immediate, powerful and dynamic. The IFRC deployed seven emergency response units (ERU) to Haiti: one 150-bed referral hospital, one Rapid Deployment Emergency Hospital, and five basic health care units. One surgical hospital and two Basic Health Care Units were deployed to Chile. The ERU system of the IFRC is a flexible and dynamic tool for emergency health response in shifting and challenging environments. Evaluations show that the system performs well during urban and rural disasters. Despite a very different baseline in the two contexts, the ERU system of IFRC can adapt to the local needs. As panorama of pathology in the aftermath of an earthquake changes, the ERU system adapts and continues supporting the local health care system in its recovery.
(A9) Search and Rescue Underestimated
Authors: Gruskin M.A.
Published: May 2011

Background

Search and rescue plays a major role in today's society. Whether lost at sea, stranded in a remote area, or trapped in a confined space, countless rescuers and volunteers will attempt to find you and get you to safety.

Discussion and Observations

Rescue teams consist of highly trained professionals including firefighters, EMT's, paramedics and other local volunteers who are willing to risk their lives to help others. Special teams and robotics were sent into ground zero after 9/11, locating and providing immediate extrication to those who were injured. The U.S Coast Guard's search and rescue efforts during Katrina were crucial saving countless lives in New Orleans.