bluuebunny/crossref_metadata_2025 huggingface dataset:
Numerical Simulation of Bubble Cluster Induced Flow by Three-Dimensional Vortex-in-Cell Method
Authors: Chen Bin , Wang Zhiwei , Uchiyama Tomomi
Published: March 2014

The behavior of air bubble clusters rising in water and the induced flow field are numerically studied using a three-dimensional two-way coupling algorithm based on a vortex-in-cell (VIC) method. In this method, vortex elements are convected in the Lagrangian frame and the liquid velocity field is solved from the Poisson equation of potential on the Eulerian grid. Two-way coupling is implemented by introducing a vorticity source term induced by the gradient of void fraction. Present simulation results are favorably compared with the measured results of bubble plume, which verifies the validity of the proposed VIC method. The rising of a single bubble cluster as well as two tandem bubble clusters are simulated. The mechanism of the aggregation effect in the rising process of bubble cluster is revealed and the transient processes of the generation, rising, strengthening, and separation of a vortex ring structure with bubble clusters are illustrated and analyzed in detail. Due to the aggregation, the average rising velocity increases with void fraction and is larger than the terminal rising velocity of single bubble. For the two tandem bubble cluster cases, the aggregation effect is stronger for smaller initial cluster distance, and both the strength of the induced vortex structure and the average bubble rising velocity are larger. For the 20 mm cluster distance case, the peak velocity of the lower cluster is about 2.7 times that of the terminal velocity of the single bubble and the peak average velocity of two clusters is about 2 times larger. While for the 30 mm cluster distance case, both the peak velocity of the lower cluster and two clusters are about 1.7 times that of the terminal velocity of the single bubble.
Comparative Study of Cooling Performance of Automobile Radiator Using Al2O3-Water and Carbon Nanotube-Water Nanofluid
Authors: Chougule Sandesh S. , Sahu S. K.
Published: March 2014

In the present study, the forced convective heat transfer performance of two different nanofluids, namely, Al2O3-water and CNT-water has been studied experimentally in an automobile radiator. Four different concentrations of nanofluid in the range of 0.15–1 vol. % were prepared by the additions nanoparticles into the water as base fluid. The coolant flow rate is varied in the range of 2 l/min–5 l/min. Nanocoolants exhibit enormous change in the heat transfer compared with the pure water. The heat transfer performance of CNT-water nanofluid was found to be better than Al2O3-water nanocoolant. Furthermore, the Nusselt number is found to increase with the increase in the nanoparticle concentration and nanofluid velocity.
Excitation-Induced Stability in a Bistable Duffing Oscillator: Analysis and Experiments
Authors: Wu Z. , Harne R. L. , Wang K. W.
Published: March 2014

The excitation-induced stability (EIS) phenomenon in a harmonically excited bistable Duffing oscillator is studied in this paper. Criteria to predict system and excitation conditions necessary to maintain EIS are derived through a combination of the method of harmonic balance, perturbation theory, and stability theory for Mathieu's equation. Accuracy of the criteria is verified by analytical and numerical studies. We demonstrate that damping primarily determines the likelihood of attaining EIS response when several dynamics coexist while excitation level governs both the existence and frequency range of the EIS region, providing comprehensive guidance for realizing or avoiding EIS dynamics. Experimental results are in good agreement regarding the comprehensive influence of excitation conditions on the inducement of EIS.
Identification of Random Excitation Fields From Vibratory Responses With Application to Multisupported Tubes Excited by Flow Turbulence
Authors: Antunes Jose , Borsoi Laurent , Delaune Xavier , Piteau Philippe
Published: March 2014

In this paper, we address the identification of the spectral and spatial features of random flow excitations for multisupported tubular components such as steam generator tubes and nuclear fuel rods. In the proposed work, source identification is performed from a set of measured vibratory responses, in the following manner: (1) The modal response spectra and modeshape amplitudes at the measurement locations are first extracted through a blind decomposition of the physical response matrix, using the second order blind identification (SOBI) method; (2) the continuous modeshapes are interpolated from the identified values at the measurement locations; (3) the system modal parameters are identified from the modal responses using a simple single degree of freedom (SDOF) fitting technique; (4) inversion from the modal response spectra is performed for the identification of the modal excitation spectra; (5) finally, an equivalent physical excitation spectrum as well as the flow velocity profiles are estimated. The proposed approach is illustrated with identification results based on realistic numerical simulations of a multisupported tube under linear support conditions.
Investigation of Adhesion Formation in New Stainless Steel Trim Spring Operated Pressure Relief Valves
Authors: Bukowski Julia V. , Gross Robert E. , Goble William M.
Published: March 2014

Examination of proof test data for new (not previously installed) stainless steel (SS) trim spring operated pressure relief valves (SOPRV) reveals that adhesions form between the seat and disk in about 46% of all such SOPRV. The forces needed to overcome these adhesions can be sufficiently large to cause the SOPRV to fail its proof test (FPT) prior to installation. Furthermore, a significant percentage of SOPRV which are found to FPT are also found to “fail to open” (FTO) meaning they would not relief excess pressure in the event of an overpressure event. The cases where adhesions result in FTO or FPT appear to be confined to SOPRV with diameters less than or equal to 1 in. and set pressures less than 150 pounds per square inch gauge (psig) and the FTO are estimated to occur in 0.31% to 2.00% of this subpopulation of SS trim SOPRV. The reliability and safety implications of these finding for end users who do not perform pre-installation testing of SOPRV are discussed.
A Dual-Arm 7-Degrees-of-Freedom Haptics-Enabled Teleoperation Test Bed for Minimally Invasive Surgery
Authors: Talasaz Ali , Luisa Trejos Ana , Perreault Simon , Bassan Harmanpreet , Patel Rajni V.
Published: March 2014

This paper describes a dual-arm teleoperation (master-slave) system which has been developed to explore the effect of haptics in robotics-assisted minimally invasive surgery (RAMIS). This setup is capable of measuring forces in 7 degrees of freedom (DOF) and fully reflecting them to the operator through two 7-DOF haptic interfaces. An application of the test bed is in enabling the evaluation of the effect of replacing haptic feedback by other sensory cues such as visual representation of haptic information (sensory substitution). This paper discusses the design rationale, kinematic analysis and dynamic modeling of the robot manipulators, and the control system developed for the setup. Using the accurate model developed in this paper, a highly transparent haptics-enabled system can be achieved and used in robot-assisted telesurgery. Validation results obtained through experiments are presented and demonstrate the correctness and effectiveness of the developed models. The application of the setup for two RAMIS surgical tasks, a suture manipulation task and a tumor localization task, is described with different haptics modalities available through the developed haptics-enabled system for each application.
Stochastic Dynamic Modeling of the Human Brain EEG Signal
Authors: Ghorbanian Parham , Ramakrishnan Subramanian , Simon Adam J. , Ashrafiuon Hashem
Published: March 2014

The occurrence and risk of recurrence of brain related injuries and diseases are difficult to characterize due to various factors including inter-individual variability. A useful approach is to analyze the brain electroencephalogram (EEG) for differences in brain frequency bands in the signals obtained from potentially injured and healthy normal subjects. However, significant shortcomings include: (1) contrary to empirical evidence, current spectral signal analysis based methods often assume that the EEG signal is linear and stationary; (2) nonlinear time series analysis methods are mostly numerical and do not possess any predictive features. In this work, we develop models based on stochastic differential equations that can output signals with similar frequency and magnitude characteristics of the brain EEG. Initially, a coupled linear oscillator model with a large number of degrees of freedom is developed and shown to capture the characteristics of the EEG signal in the major brain frequency bands. Then, a nonlinear stochastic model based on the Duffing oscillator with far fewer degrees of freedom is developed and shown to produce outputs that can closely match the EEG signal. It is shown that such a compact nonlinear model can provide better insight into EEG dynamics through only few parameters, which is a step towards developing a framework with predictive capabilities for addressing brain injuries.
Environmental Dependence of Stationary-Phase Metabolism in Bacillus subtilis and Escherichia coli
Authors: Chubukov Victor , Sauer Uwe
Published: March 2014

When microbes lack the nutrients necessary for growth, they enter stationary phase. In cases when energy sources are still present in the environment, they must decide whether to continue to use their metabolic program to harvest the available energy. Here we characterized the metabolic response to a variety of types of nutrient starvation in
Escherichia coli
and
Bacillus subtilis
. We found that
E. coli
exhibits a range of phenotypes, with the lowest metabolic rates under nitrogen starvation and highest rates under magnesium starvation. In contrast, the phenotype of
B. subtilis
was dominated by its decision to form metabolically inactive endospores. While its metabolic rates under most conditions were thus lower than those of
E. coli
, when sporulation was suppressed by a genetic perturbation or an unnatural starvation condition, the situation was reversed. To further probe stationary-phase metabolism, we used quantitative metabolomics to investigate possible small-molecule signals that may regulate the metabolic rate of
E. coli
and initiate sporulation in
B. subtilis
. We hypothesize a role for phosphoenolpyruvate (PEP) in regulating
E. coli
glucose uptake and for the redox cofactors NAD(H) and NADP(H) in initiation of sporulation. Our work is directly relevant to synthetic biology and metabolic engineering, where active metabolism during stationary phase, which uncouples production from growth, remains an elusive goal.
Altered Transcription of Murine Genes Induced in the Small Bowel by Administration of Probiotic Strain Lactobacillus rhamnosus HN001
Authors: Tannock Gerald W. , Taylor Corinda , Lawley Blair , Loach Diane , Gould Maree , Dunn Amy C. , McLellan Alexander D. , Black Michael A. , McNoe Les , Dekker James , Gopal Pramod , Collett Michael A.
Published: March 2014

Lactobacillus rhamnosusHN001 is a probiotic strain reported to increase resistance to epithelium-adherent and -invasive intestinal pathogens in experimental animals. To increase understanding of the relationship between strain HN001 and the bowel, transcription of selected genes in the mucosa of the murine small bowel was measured. Mice previously naive to lactobacilli (Lactobacillus-free mice) were examined after daily exposure to HN001 in drinking water. Comparisons were made to results from matchedLactobacillus-free mice. Infant and adult mice were investigated to provide a temporal view of gene expression in response to exposure to HN001. Genessgk1,angptl4, andhspa1b, associated with the apoptosis pathway, were selected for investigation by reverse transcription-quantitative PCR on the basis of a preliminary duodenal DNA microarray screen. Normalized togapdhgene transcription, these three genes were upregulated after 6 to 10 days exposure of adult mice to HN001. Angptl4 was shown by immunofluorescence to be upregulated in duodenal epithelial cells of mucosal samples. Epithelial cell migration was faster in HN001-exposed mice than in theLactobacillus-free controls. Transcriptional responses in infant mice differed according to bowel region and age. For example,sgk1was upregulated in duodenal, jejunal, and ileal mucosa of mice less than 25 days old, whereasangptl4andhspa1bwere upregulated at 10 days in the duodenum but downregulated in the jejunal mucosa until mice were 25 days old. Overall, the results provide links between a probiotic strain, mucosal gene expression, and host phenotype, which may be useful in delineating mechanisms of probiotic action.
The Iron Stimulon and Fur Regulon of Geobacter sulfurreducens and Their Role in Energy Metabolism
Authors: Embree Mallory , Qiu Yu , Shieu Wendy , Nagarajan Harish , O'Neil Regina , Lovley Derek , Zengler Karsten
Published: March 2014

Iron plays a critical role in the physiology of
Geobacter
species. It serves as both an essential component for proteins and cofactors and an electron acceptor during anaerobic respiration. Here, we investigated the iron stimulon and ferric uptake regulator (Fur) regulon of
Geobacter sulfurreducens
to examine the coordination between uptake of Fe(II) and the reduction of Fe(III) at the transcriptional level. Gene expression studies across a variety of different iron concentrations in both the wild type and a Δ
fur
mutant strain were used to determine the iron stimulon. The stimulon consists of a broad range of gene products, ranging from iron-utilizing to central metabolism and iron reduction proteins. Integration of gene expression and chromatin immunoprecipitation (ChIP) data sets assisted in the identification of the Fur transcriptional regulatory network and Fur's role as a regulator of the iron stimulon. Additional physiological and transcriptional analyses of
G. sulfurreducens
grown with various Fe(II) concentrations revealed the depth of Fur's involvement in energy metabolism and the existence of redundancy within the iron-regulatory network represented by IdeR, an alternative iron transcriptional regulator. These characteristics enable
G. sulfurreducens
to thrive in environments with fluctuating iron concentrations by providing it with a robust mechanism to maintain tight and deliberate control over intracellular iron homeostasis.
Enhanced Control of Cucumber Wilt Disease by Bacillus amyloliquefaciens SQR9 by Altering the Regulation of Its DegU Phosphorylation
Authors: Xu Zhihui , Zhang Ruifu , Wang Dandan , Qiu Meihua , Feng Haichao , Zhang Nan , Shen Qirong
Published: March 2014

Bacillus amyloliquefaciens
strain SQR9, isolated from the cucumber rhizosphere, suppresses the growth of
Fusarium oxysporum
in the cucumber rhizosphere and protects the host plant from pathogen invasion through efficient root colonization. In the Gram-positive bacterium
Bacillus
, the response regulator DegU regulates genetic competence, swarming motility, biofilm formation, complex colony architecture, and protease production. In this study, we report that stepwise phosphorylation of DegU in
B. amyloliquefaciens
SQR9 can influence biocontrol activity by coordinating multicellular behavior and regulating the synthesis of antibiotics. Results from
in vitro
and
in situ
experiments and quantitative PCR (qPCR) studies demonstrate the following: (i) that the lowest level of phosphorylated DegU (DegU∼P) (the
degQ
mutation) impairs complex colony architecture, biofilm formation, colonization activities, and biocontrol efficiency of
Fusarium
wilt disease but increases the production of macrolactin and bacillaene, and (ii) that increasing the level of DegU∼P by
degQ
and
degSU
overexpression significantly improves complex colony architecture, biofilm formation, colonization activities, production of the antibiotics bacillomycin D and difficidin, and efficiency of biocontrol of
Fusarium
wilt disease. The results offer a new strategy to enhance the biocontrol efficacy of
Bacillus amyloliquefaciens
SQR9.
Randomized Controlled Study of the Safety and Immunogenicity of Pneumococcal Vaccine Formulations Containing PhtD and Detoxified Pneumolysin with Alum or Adjuvant System AS02
V
in Elderly Adults
Authors: Pauksens Karlis , Nilsson Anna C. , Caubet Magalie , Pascal Thierry G. , Van Belle Pascale , Poolman Jan T. , Vandepapelière Pierre G. , Verlant Vincent , Vink Peter E.
Published: March 2014

Six vaccine formulations containing AS02
V
or alum (aluminum phosphate [AlPO
4
]) adjuvant with pneumococcal proteins, pneumococcal histidine triad D (PhtD), and/or detoxified pneumolysin (dPly), either as a polysaccharide carrier in an 8-valent pneumococcal conjugate vaccine (8PCV) or as free (unconjugated) proteins, were evaluated in adults -65 to 85 years of age. In this phase I observer-blind study, 167 healthy subjects were randomized to receive two doses (days 0 and 60) of 10 or 30 μg PhtD-dPly plus AS02
V
or alum, 8PCV plus AS02
V
or alum, or one dose (day 0) of 23-valent polysaccharide pneumococcal vaccine (23PPV) as a control (placebo on day 60). The safety, reactogenicity, and antibody-specific responses to these vaccines were evaluated. No vaccine-related serious adverse events were reported. The incidences of solicited local and specific general (fatigue and myalgia) symptoms tended to be higher in the AS02
V
groups than in other groups. Anti-PhtD and anti-Ply antibody responses were observed in all groups except the control group. One month post-dose 2, the anti-PhtD and anti-Ply antibody geometric mean concentrations tended to be higher with AS02
V
than with alum, higher with a dose of 30 μg than with 10 μg for PhtD-dPly and higher with 30-μg PhtD-dPly formulations than with conjugated PhtD and dPly (8PCV) formulations. Functional antibody responses, measured by an opsonophagocytic activity assay, tended to be higher with 8PCV than with 23PPV. In conclusion, vaccine formulations containing free or conjugated PhtD and dPly had acceptable reactogenicity and safety profiles in elderly adults. Immune responses were enhanced with an AS02
V
-adjuvanted formulation containing free 30-μg PhtD-dPly compared to those with alum adjuvant and conjugated proteins. (This study has been registered at
ClinicalTrials.gov
under registration no. NCT00756067.)
The Path to Triacylglyceride Obesity in the
sta6
Strain of Chlamydomonas reinhardtii
Authors: Goodenough Ursula , Blaby Ian , Casero David , Gallaher Sean D. , Goodson Carrie , Johnson Shannon , Lee Jae-Hyeok , Merchant Sabeeha S. , Pellegrini Matteo , Roth Robyn , Rusch Jannette , Singh Manmilan , Umen James G. , Weiss Taylor L. , Wulan Tuya
Published: March 2014

When the
sta6
(starch-null) strain of the green microalga
Chlamydomonas reinhardtii
is nitrogen starved in acetate and then “boosted” after 2 days with additional acetate, the cells become “obese” after 8 days, with triacylglyceride (TAG)-filled lipid bodies filling their cytoplasm and chloroplasts. To assess the transcriptional correlates of this response, the
sta6
strain and the starch-forming
cw15
strain were subjected to RNA-Seq analysis during the 2 days prior and 2 days after the boost, and the data were compared with published reports using other strains and growth conditions. During the 2 h after the boost, ∼425 genes are upregulated ≥2-fold and ∼875 genes are downregulated ≥2-fold in each strain. Expression of a small subset of “sensitive” genes, encoding enzymes involved in the glyoxylate and Calvin-Benson cycles, gluconeogenesis, and the pentose phosphate pathway, is responsive to culture conditions and genetic background as well as to boosting. Four genes—encoding a diacylglycerol acyltransferase (
DGTT2
), a glycerol-3-P dehydrogenase (
GPD3
), and two candidate lipases (Cre03.g155250 and Cre17.g735600)—are selectively upregulated in the
sta6
strain. Although the bulk rate of acetate depletion from the medium is not boost enhanced, three candidate acetate permease-encoding genes in the
GPR1/FUN34/YaaH
superfamily are boost upregulated, and 13 of the “sensitive” genes are strongly responsive to the cell's acetate status. A cohort of 64 autophagy-related genes is downregulated by the boost. Our results indicate that the boost serves both to avert an autophagy program and to prolong the operation of key pathways that shuttle carbon from acetate into storage lipid, the combined outcome being enhanced TAG accumulation, notably in the
sta6
strain.
Pbx Proteins in Cryptococcus neoformans Cell Wall Remodeling and Capsule Assembly
Authors: Kumar Pardeep , Heiss Christian , Santiago-Tirado Felipe H. , Black Ian , Azadi Parastoo , Doering Tamara L.
Published: March 2014

The cryptococcal capsule is a critical virulence factor of an important pathogen, but little is known about how it is associated with the cell or released into the environment. Two mutants lacking
PBX1
and
PBX2
were found to shed reduced amounts of the capsule polysaccharide glucuronoxylomannan (GXM). Nuclear magnetic resonance, composition, and physical analyses showed that the shed material was of normal mass but was slightly enriched in xylose. In contrast to previous reports, this material contained no glucose. Notably, the capsule fibers of
pbx
Δ mutant cells grown under capsule-inducing conditions were present at a lower than usual density and were loosely attached to the cell wall. Mutant cell walls were also defective, as indicated by phenotypes including abnormal cell morphology, reduced mating filamentation, and altered cell integrity. All observed phenotypes were shared between the two mutants and exacerbated in a double mutant. Consistent with a role in surface glycan synthesis, the Pbx proteins localized to detergent-resistant membrane domains. These results, together with the sequence motifs in the Pbx proteins, suggest that Pbx1 and Pbx2 are redundant proteins that act in remodeling the cell wall to maintain normal cell morphology and precursor availability for other glycan synthetic processes. Their absence results in aberrant cell wall growth and metabolic imbalance, which together impact cell wall and capsule synthesis, cell morphology, and capsule association. The surface changes also lead to increased engulfment by host phagocytes, consistent with the lack of virulence of
pbx
mutants in animal models.
Inhibition and Structure of Toxoplasma gondii Purine Nucleoside Phosphorylase
Authors: Donaldson Teraya M. , Cassera María B. , Ho Meng-Chiao , Zhan Chenyang , Merino Emilio F. , Evans Gary B. , Tyler Peter C. , Almo Steven C. , Schramm Vern L. , Kim Kami
Published: March 2014

The intracellular pathogen
Toxoplasma gondii
is a purine auxotroph that relies on purine salvage for proliferation. We have optimized
T. gondii
purine nucleoside phosphorylase (
Tg
PNP) stability and crystallized
Tg
PNP with phosphate and immucillin-H, a transition-state analogue that has high affinity for the enzyme. Immucillin-H bound to
Tg
PNP with a dissociation constant of 370 pM, the highest affinity of 11 immucillins selected to probe the catalytic site. The specificity for transition-state analogues indicated an early dissociative transition state for
Tg
PNP. Compared to
Plasmodium falciparum
PNP, large substituents surrounding the 5′-hydroxyl group of inhibitors demonstrate reduced capacity for
Tg
PNP inhibition. Catalytic discrimination against large 5′ groups is consistent with the inability of
Tg
PNP to catalyze the phosphorolysis of 5′-methylthioinosine to hypoxanthine. In contrast to mammalian PNP, the 2′-hydroxyl group is crucial for inhibitor binding in the catalytic site of
Tg
PNP. This first crystal structure of TgPNP describes the basis for discrimination against 5′-methylthioinosine and similarly 5′-hydroxy-substituted immucillins; structural differences reflect the unique adaptations of purine salvage pathways of
Apicomplexa
.
The Haemophilus Cryptic Genospecies Cha Adhesin Has at Least Two Variants That Differ in Host Cell Binding, Bacterial Aggregation, and Biofilm Formation Properties
Authors: McCann Jessica R. , Sheets Amanda J. , Grass Susan , St. Geme Joseph W.
Published: March 2014

The
Haemophilus
cryptic genospecies (HCG) causes genital tract infections in pregnant and postpartum women and respiratory infections in neonates. The major surface adhesin in HCG is called Cha, which mediates bacterial adherence to cultured human epithelial cells. In this study, we report that there are two antigenically distinct variants of Cha, dubbed Cha1 and Cha2. These variants are encoded by the same genetic locus in diverse strains and have nearly identical N-terminal export and C-terminal surface anchoring domains but significantly different internal adhesive domains. Based on the comparison of derivatives of a laboratory strain of
Haemophilus influenzae
expressing either surface-associated Cha1 or surface-associated Cha2, Cha1 mediates a higher level of adherence to cultured human epithelial cells and Cha2 mediates a higher level of adherence to abiotic surfaces. We hypothesize that variation in the Cha1 and Cha2 internal region results in changes in binding specificity or binding affinity and may be associated with adaptation to different host environments during colonization and disease.
Scientific publications in respiratory journals from Chinese authors in various parts of North Asia: a 10-year survey of literature
Authors: Ye Bo , Du Ting-Ting , Xie Ting , Ji Jun-Tao , Zheng Zhao-Hong , Liao Zhuan , Hu Liang-Hao , Li Zhao-Shen
Published: March 2014

Objectives

Respiratory disease remains one of the leading causes of morbidity and mortality in China. However, little is known about the research status of respirology in three major regions of China—Mainland (ML), Hong Kong (HK) and Taiwan (TW). A 10-year survey of literature was conducted to compare the three regions’ outputs in the research of respirology.

Design

A bibliometric study.

Setting

China.

Participants and outcome measures

A literature search in PubMed database, updated as of September 2012, led to the identification of the related articles from 2000 to 2009. The number of total articles, randomised controlled trials, case reports, meta-analysis, impact factors (IF), citations and articles published in top general medicine journals was collected for quantity and quality comparisons.

Results

2208 articles were collected, 814 from ML, 909 from TW and 485 from HK. The total number of articles from the three regions has increased significantly from 2000 to 2009. The number of articles published per year from ML has exceeded that from HK in 2005 and TW in 2008. The accumulated IF of articles from TW (3192.417) was much higher than that from ML (2409.956) and HK (1898.312). HK got the highest average IF of respirology articles and the majority of articles were published in top general medicine journals.

Conclusions

The total number of published articles from the three major regions of China has increased notably from 2000 to 2009. The annual number of publications by ML researchers exceeded those from TW and HK. However, the quality of articles from TW and HK is better than that from ML.
A longitudinal, multicentre, cohort study of community rehabilitation service delivery in long-term neurological conditions
Authors: Siegert Richard J , Jackson Diana M , Playford E Diane , Fleminger Simon , Turner-Stokes Lynne
Published: March 2014

Objectives

Part A: To pilot the use of a register to identify and monitor patients with complex needs arising from long-term neurological conditions.Part B: To determine the extent to which patients’ needs for health and social services are met following discharge to the community after inpatient rehabilitation; to identify which factors predict unmet needs and to explore the relationship between service provision and outcomes at 12 months.

Design

A multicentre, prospective, cohort study surveying participants at 1, 6 and 12 months using postal/online questionnaires and telephone interview.

Setting

Consecutive discharges to the community from all nine tertiary, specialist, inpatient neurorehabilitation services in London over 18 months in 2010–2011.

Participants

Of 576 admissions 428 patients were recruited at discharge: 256 responded at 4 weeks, 212 at 6 months and 190 at 12 months.

Measures

Neurological Impairment Scale, The Needs and Provision Complexity Scale, The Northwick Park Dependency Scale, Community Integration Questionnaire, Zarit Burden Inventory.

Results

n=322 (75%) expressed willingness to be registered, but in practice less than half responded to questionnaires at 6 and 12 months (49% and 44%, respectively), despite extensive efforts to contact them, with no significant differences between responders and non-responders. Significant unmet needs were identified within the first year following discharge, particularly in rehabilitation, social work support and provision of specialist equipment. Dependency for basic care and motor and cognitive impairment predicted services received, together accounting for 40% of the variance. Contra to expectation, patients whose rehabilitation needs were met were more dependent and less well integrated at 12 months post discharge than those with unmet needs.

Conclusions

Registration is acceptable to most patients, but questionnaires/telephone interviews may not be the most efficient way to reach them. When community resources are limited, service provision tends to be focused on the most dependent patients.

Registration

The study was registered with the NIHR Comprehensive Local Research Network: ID number 7503
Engineering Complex Metabolic Pathways in Plants
Authors: Farré Gemma , Blancquaert Dieter , Capell Teresa , Van Der Straeten Dominique , Christou Paul , Zhu Changfu
Published: March 2014

Metabolic engineering can be used to modulate endogenous metabolic pathways in plants or introduce new metabolic capabilities in order to increase the production of a desirable compound or reduce the accumulation of an undesirable one. In practice, there are several major challenges that need to be overcome, such as gaining enough knowledge about the endogenous pathways to understand the best intervention points, identifying and sourcing the most suitable metabolic genes, expressing those genes in such a way as to produce a functional enzyme in a heterologous background, and, finally, achieving the accumulation of target compounds without harming the host plant. This article discusses the strategies that have been developed to engineer complex metabolic pathways in plants, focusing on recent technological developments that allow the most significant bottlenecks to be overcome.
Plant Molecular Pharming for the Treatment of Chronic and Infectious Diseases
Authors: Stoger Eva , Fischer Rainer , Moloney Maurice , Ma Julian K.-C.
Published: March 2014

Plant molecular pharming has emerged as a niche technology for the manufacture of pharmaceutical products indicated for chronic and infectious diseases, particularly for products that do not fit into the current industry-favored model of fermenter-based production campaigns. In this review, we explore the areas where molecular pharming can make the greatest impact, including the production of pharmaceuticals that have novel glycan structures or that cannot be produced efficiently in microbes or mammalian cells because they are insoluble or toxic. We also explore the market dynamics that encourage the use of molecular pharming, particularly for pharmaceuticals that are required in small amounts (such as personalized medicines) or large amounts (on a multi-ton scale, such as blood products and microbicides) and those that are needed in response to emergency situations (pandemics and bioterrorism). The impact of molecular pharming will increase as the platforms become standardized and optimized through adoption of good manufacturing practice (GMP) standards for clinical development, offering a new opportunity to produce inexpensive medicines in regional markets that are typically excluded under current business models.
Sucrose Metabolism: Gateway to Diverse Carbon Use and Sugar Signaling
Authors: Ruan Yong-Ling
Published: March 2014

Sucrose metabolism plays pivotal roles in development, stress response, and yield formation, mainly by generating a range of sugars as metabolites to fuel growth and synthesize essential compounds (including protein, cellulose, and starch) and as signals to regulate expression of microRNAs, transcription factors, and other genes and for crosstalk with hormonal, oxidative, and defense signaling. This review aims to capture the most exciting developments in this area by evaluating (a) the roles of key sucrose metabolic enzymes in development, abiotic stress responses, and plant–microbe interactions; (b) the coupling between sucrose metabolism and sugar signaling from extra- to intracellular spaces; (c) the different mechanisms by which sucrose metabolic enzymes could perform their signaling roles; and (d) progress on engineering sugar metabolism and transport for high yield and disease resistance. Finally, the review outlines future directions for research on sugar metabolism and signaling to better understand and improve plant performance.
Molecular Control of Cell Specification and Cell Differentiation During Procambial Development
Authors: Furuta Kaori Miyashima , Hellmann Eva , Helariutta Ykä
Published: March 2014

Land plants develop vascular tissues that enable the long-distance transport of water and nutrients in xylem and phloem, provide mechanical support for their vertical growth, and produce cells in radial growth. Vascular tissues are produced in many parts of the plant and during different developmental stages. Early vascular development is focused in procambial meristems, and in some species it continues during the secondary phase of plant development in cambial meristems. In this review, we highlight recent progress in understanding procambial development. This involves the analysis of stem cell–like properties of procambial tissues, specification of xylem and phloem, and differentiation of the conductive tissues. Several major plant hormones, small-RNA species, and transcriptional networks play a role in vascular development. We describe current approaches to integrating these networks as well as their potential role in explaining the diversity and evolution of plant vascular systems.
High-Resolution Structure of the Eukaryotic 80S Ribosome
Authors: Yusupova Gulnara , Yusupov Marat
Published: March 2014

The high-resolution structure of the eukaryotic ribosome from yeast, determined at 3.0-Å resolution, permitted the unambiguous determination of the protein side chains, eukaryote-specific proteins, protein insertions, and ribosomal RNA expansion segments of the 80 proteins and ∼5,500 RNA bases that constitute the 80S ribosome. A comparison between this first atomic model of the entire 80S eukaryotic ribosome and previously determined structures of bacterial ribosomes confirmed early genetic and structural data indicating that they share an evolutionarily conserved core of ribosomal RNA and proteins. It also confirmed the conserved organization of essential functional sites, such as the peptidyl transferase center and the decoding site. New structural information about eukaryote-specific elements, such as expansion segments and new ribosomal proteins, forms the structural framework for the design and analysis of experiments that will explore the eukaryotic translational apparatus and the evolutionary forces that shaped it. New nomenclature for ribosomal proteins, based on the names of protein families, has been proposed.
Selection-Based Discovery of Druglike Macrocyclic Peptides
Authors: Passioura Toby , Katoh Takayuki , Goto Yuki , Suga Hiroaki
Published: March 2014

Macrocyclic peptides are an emerging class of therapeutics that can modulate protein–protein interactions. In contrast to the heavily automated high-throughput screening systems traditionally used for the identification of chemically synthesized small-molecule drugs, peptide-based macrocycles can be synthesized by ribosomal translation and identified using in vitro selection techniques, allowing for extremely rapid (hours to days) screening of compound libraries comprising more than 1013 different species. Furthermore, chemical modification of translated peptides and engineering of the genetic code have greatly expanded the structural diversity of the available peptide libraries. In this review, we discuss the use of these technologies for the identification of bioactive macrocyclic peptides, emphasizing recent developments.
Biosynthesis and Export of Bacterial Lipopolysaccharides
Authors: Whitfield Chris , Trent M. Stephen
Published: March 2014

Lipopolysaccharide molecules represent a unique family of glycolipids based on a highly conserved lipid moiety known as lipid A. These molecules are produced by most gram-negative bacteria, in which they play important roles in the integrity of the outer-membrane permeability barrier and participate extensively in host–pathogen interplay. Few bacteria contain lipopolysaccharide molecules composed only of lipid A. In most forms, lipid A is glycosylated by addition of the core oligosaccharide that, in some bacteria, provides an attachment site for a long-chain O-antigenic polysaccharide. The complexity of lipopolysaccharide structures is reflected in the processes used for their biosynthesis and export. Rapid growth and cell division depend on the bacterial cell's capacity to synthesize and export lipopolysaccharide efficiently and in large amounts. We review recent advances in those processes, emphasizing the reactions that are essential for viability.
Magnetic Oxide Heterostructures
Authors: Bhattacharya Anand , May Steven J.
Published: March 2014

Complex transition metal oxides have played a central role in the study of magnetic materials, serving as model systems for explorations of fundamental exchange interactions and the relationships between structural, electronic, and magnetic responses. Enabled by advances in epitaxial synthesis techniques, abrupt heterointerfaces and superlattices have emerged as a powerful platform for engineering novel magnetic behavior in oxides. Following a brief introduction to the dominant exchange mechanisms in metal oxides, we review the general means by which interfacial magnetism can be tailored in ABO3 perovskites, including interfacial charge transfer, epitaxial strain and structural coupling, orbital polarizations and reconstructions, and tailoring exchange interactions via cation ordering. Recent examples are provided to illustrate how these strategies have been employed at isolated interfaces and in short-period superlattices. We conclude by briefly discussing underexplored and emerging research directions in the field.
The Political Economy of Development in China and Vietnam
Authors: Malesky Edmund , London Jonathan
Published: March 2014

Two theories predominate in discussions of why China and Vietnam have, over the past three decades, achieved such rapid economic growth. The first argues that their startling performance can be explained by economic factors associated with late industrialization. The second proposes that China and Vietnam represent novel models of political economic organization that need to be better studied and understood. In this essay we review the voluminous literature on the political economy of China and Vietnam, evaluating the critical debates over the economic benefits of decentralization, experimentation, and state-led development. Although the debate remains unsettled, analysis suggests that growth in the two countries was most robust during periods of state withdrawal from the economy and that current economic difficulties in both countries are now arising from the scale and character of the state's role in both economies.
Is There an Islamist Political Advantage?
Authors: Cammett Melani , Luong Pauline Jones
Published: March 2014

There is a widespread presumption that Islamists have an advantage over their opponents when it comes to generating mass appeal and winning elections. The question remains, however, as to whether these advantages—or, what we refer to collectively as an Islamist political advantage—actually exist. We argue that—to the extent that Islamists have a political advantage—the primary source of this advantage is reputation rather than the provision of social services, organizational capacity, or ideological hegemony. Our purpose is not to dismiss the main sources of the Islamist political advantage identified in scholarly literature and media accounts, but to suggest a different causal path whereby each of these factors individually and sometimes jointly promotes a reputation for Islamists as competent, trustworthy, and pure. It is this reputation for good governance that enables Islamists to distinguish themselves in the streets and at the ballot box.
Spiders in motion: demonstrating adaptation, structure-function relationships, and trade-offs in invertebrates
Authors: Bowlin Melissa S. , McLeer Dorothy F. , Danielson-Francois Anne M.
Published: March 2014

Evolutionary history and structural considerations constrain all aspects of animal physiology. Constraints on invertebrate locomotion are especially straightforward for students to observe and understand. In this exercise, students use spiders to investigate the concepts of adaptation, structure-function relationships, and trade-offs. Students measure burst and endurance performance in several taxonomic families of spiders whose ecological niches have led to different locomotory adaptations. Based on observations of spiders in their natural habitat and prior background information, students make predictions about spider performance. Students then construct their own knowledge by performing a hands-on, inquiry-based scientific experiment where the results are not necessarily known. Depending on the specific families chosen, students can observe that web-dwelling spiders have more difficulty navigating complex terrestrial terrain than ground-dwelling spiders and that there is a trade-off between burst performance and endurance performance in spiders. Our inexpensive runway design allows for countless variations on this basic experiment; for example, we have successfully used runways to show students how the performance of heterothermic ectotherms varies with temperature. High levels of intra- and interindividual variation in performance underscore the importance of using multiple trials and statistical tests. Finally, this laboratory activity can be completely student driven or standardized, depending on the instructor's preference.
Using a classic paper by Bell as a platform for discussing the role of corollary discharge-like signals in sensory perception and movement control
Authors: Cecala Aaron L.
Published: March 2014

Decades of behavioral observations have shown that invertebrate and vertebrate species have the ability to distinguish between self-generated afferent inputs versus those that are generated externally. In the present article, I describe activities focused around the discussion of a classic American Physiological Society paper by Curtis C. Bell that lays the foundation for students to investigate the neural substrate underlying this ability. Students will leave this activity being able to 1) describe the technical aspects and limitations of an electric fish preparation commonly used to acquire single unit (extracellular) neurophysiological data, 2) provide physiological evidence showing that the activity of principal cells in the posterior lateral line lobe of the electric fish brain reflects that of a reafference comparator that could be used in dissociating self-generated versus externally generated sensory signals, and 3) knowledgeably discuss hypotheses concerning the role of corollary discharge and cerebellar-like structures in vertebrate and invertebrate species. The skills and background knowledge gained in this activity lay the platform for advanced study of scientific investigations into sensory, motor, and cognitive processes in undergraduate, graduate, or medical school curricula.
Portable conduction velocity experiments using earthworms for the college and high school neuroscience teaching laboratory
Authors: Shannon Kyle M. , Gage Gregory J. , Jankovic Aleksandra , Wilson W. Jeffrey , Marzullo Timothy C.
Published: March 2014

The earthworm is ideal for studying action potential conduction velocity in a classroom setting, as its simple linear anatomy allows easy axon length measurements and the worm's sparse coding allows single action potentials to be easily identified. The earthworm has two giant fiber systems (lateral and medial) with different conduction velocities that can be easily measured by manipulating electrode placement and the tactile stimulus. Here, we present a portable and robust experimental setup that allows students to perform conduction velocity measurements within a 30-min to 1-h laboratory session. Our improvement over this well-known preparation is the combination of behaviorally relevant tactile stimuli (avoiding electrical stimulation) with the invention of minimal, low-cost, and portable equipment. We tested these experiments during workshops in both a high school and college classroom environment and found positive learning outcomes when we compared pre- and posttests taken by the students.
Evaluation of retention of knowledge and skills imparted to first-year medical students through basic life support training
Authors: Pande Sushma , Pande Santosh , Parate Vrushali , Pande Sanket , Sukhsohale Neelam
Published: March 2014

Poor awareness among medical graduates about basic life support (BLS) is a matter of great concern. The presence of a trained rescuer is the key determinant of ultimate survival from life-threatening emergencies. To achieve this goal, early exposure to such life-saving skills is the right decision to foster these skills for medical students, which can be reenforced in succeeding years. Forty-two first-year medical students participated in this study. The entire procedure consisted of faculty training, assessment of knowledge of students by a pretest questionnaire, a lecture, a demonstration, and hands-on training using a mannequin (with special emphasis on the site, depth, rate, and sustainment of uninterrupted chest compressions). Posttest 1 was conducted to assess the knowledge gained. The retention of knowledge and skills in the second year was evaluated by posttest 2 and directly observed procedural skills, respectively. Student feedback was collected on five-point Likert scale. Analysis using a Freidman test indicated the mean rank for posttest 1 (2.81) to be significantly higher than the pretest (1.26), indicating a gain in knowledge. The mean rank for posttest 2 (1.93) was lower than for posttest 1 (2.81) but was significantly higher compared with the pretest (1.26), indicating a significant retention of knowledge during the second year. Directly observed procedural skill evaluation showed that 7% students could perform all the seven steps correctly and that 74% students could perform three or more steps correctly, signifying a good retention of skill. Two students taught BLS skills to their family members as well. The results of this study suggest that the program provides students with sound basic knowledge and adequate practical skills in BLS.