bluuebunny/crossref_metadata_2025_split huggingface dataset:
Intracellular selection of peptide inhibitors that target disulphide‐bridged Aβ42 oligomers
Authors: Acerra Nicola , Kad Neil. M. , Cheruvara Harish , Mason Jody M. 
Published: June 2014

AbstractThe β‐amyloid (Aβ) peptide aggregates into a number of soluble and insoluble forms, with soluble oligomers thought to be the primary factor implicated in Alzheimer's disease pathology. As a result, a wide range of potential aggregation inhibitors have been developed. However, in addition to problems with solubility and protease susceptibility, many have inadvertently raised the concentration of these soluble neurotoxic species. Sandberg et al. previously reported a β‐hairpin stabilized variant of Aβ42 that results from an intramolecular disulphide bridge (A21C/A31C; Aβ42cc), which generates highly toxic oligomeric species incapable of converting into mature fibrils. Using an intracellular protein‐fragment complementation (PCA) approach, we have screened peptide libraries using E. coli that harbor an oxidizing environment to permit cytoplasmic disulphide bond formation. Peptides designed to target either the first or second β‐strand have been demonstrated to bind to Aβ42cc, lower amyloid cytotoxicity, and confer bacterial cell survival. Peptides have consequently been tested using wild‐type Aβ42 via ThT binding assays, circular dichroism, MTT cytotoxicity assays, fluorescence microscopy, and atomic force microscopy. Results demonstrate that amyloid‐PCA selected peptides function by both removing amyloid oligomers as well as inhibiting their formation. These data further support the use of semirational design combined with intracellular PCA methodology to develop Aβ antagonists as candidates for modification into drugs capable of slowing or even preventing the onset of AD.
Modifications to a commercially available linear mass spectrometer for mass‐resolved microscopy with the pixel imaging mass spectrometry (PImMS) camera
Authors: Halford E. , Winter B. , Mills M. D. , Thompson S. P. , Parr V. , John J. J. , Nomerotski A. , Vallance C. , Turchetta R. , Brouard M. 
Published: June 2014

RATIONALEImaging mass spectrometry is a powerful analytical technique capable of accessing a large volume of spatially resolved, chemical data from two‐dimensional samples. Probing the entire surface of a sample simultaneously requires a detector with high spatial and temporal resolutions, and the ability to observe events relating to different mass‐to‐charge ratios.METHODSA commercially available time‐of‐flight mass spectrometer, designed for matrix‐assisted laser desorption/ionization (MALDI) analysis, was combined with the novel pixel imaging mass spectrometry (PImMS) camera in order to perform multi‐mass, microscope‐mode imaging experiments. A number of minor modifications were made to the spectrometer hardware and ion optics so that spatial imaging was achieved for a number of small molecules.RESULTSIt was shown that a peak width of Δm50 % <  1  m/z unit across the range 200 ≤ m/z  ≤  800 can be obtained while also achieving an optimum spatial resolution of 25 µm. It was further shown that these data were obtained simultaneously for all analytes present without the need to scan the experimental parameters.CONCLUSIONSThis work demonstrates the capability of multi‐mass, microscope‐mode imaging to reduce the acquisition time of spatially distributed analytes such as multi‐arrays or biological tissue sections. It also shows that such an instrument can be commissioned by effecting relatively minor modifications to a conventional commercial machine. Copyright © 2014 John Wiley & Sons, Ltd.
A novel asymmetrical arc‐shaped electrode ion trap for improving the performance of a miniature mass spectrometer
Authors: Zhang Zhong‐yao , Li Cuiping , Ding Chuan‐fan , Xu Fuxing , Li Baoqiang , Huang Qibin , Xia Hengxin 
Published: June 2014

RATIONALEThe pivotal challenge associated with miniature mass analyzers is their proper design and construction without sacrificing performance. In order to analyze and improve the performance of a miniature linear ion trap with odd and even multipole fields, we designed a novel asymmetrical arc‐shaped electrode ion trap (AAEIT), and tested the properties of AAEITs with different dimensions.METHODSA series of asymmetrical ion traps using arc‐shaped electrodes were designed to optimize the properties (resolutions and intensity) of the coupling effects between odd and even multipole fields. Using arginine and reserpine, we evaluated the performance of mass resolution, ion intensity ratio and deduced the collision‐induced dissociation (CID) efficiency using a self‐constructed electrospray ionization mass spectrometry (ESI‐MS) platform.RESULTSAn AAEIT with field radius dimensions of 5 mm × 5.75 mm exhibits a good performance: its maximum resolution of 833 (FWHM) at m/z 175 was achieved for the side of small electrode. With this AAEIT, a tandem mass (MS/MS) capability with 91.0% CID efficiency was obtained with reserpine (m/z 609).CONCLUSIONSThe results indicated that the AAEIT, comprising both odd and even multipole fields, could act as a qualified linear ion trap mass analyzer with compact structure, high resolution, and high tandem mass analysis efficiency. It has a great potential in miniature mass spectrometry. Copyright © 2014 John Wiley & Sons, Ltd.
Contribution of thermal energy to initial ion production in matrix‐assisted laser desorption/ionization observed with 2,4,6‐trihydroxyacetophenone
Authors: Lai Yin‐Hung , Chen Bo‐Gaun , Lee Yuan Tseh , Wang Yi‐Sheng , Lin Sheng Hsien 
Published: June 2014

RATIONALEAlthough several reaction models have been proposed in the literature to explain matrix‐assisted laser desorption/ionization (MALDI), further study is still necessary to explore the important ionization pathways that occur under the high‐temperature environment of MALDI. 2,4,6‐Trihydroxyacetophenone (THAP) is an ideal compound for evaluating the contribution of thermal energy to an initial reaction with minimum side reactions.METHODSDesorbed neutral THAP and ions were measured using a crossed‐molecular beam machine and commercial MALDI‐TOF instrument, respectively. A quantitative model incorporating an Arrhenius‐type desorption rate derived from transition state theory was proposed. Reaction enthalpy was calculated using GAUSSIAN 03 software with dielectric effect. Additional evidence of thermal‐induced proton disproportionation was given by the indirect ionization of THAP embedded in excess fullerene molecules excited by a 450 nm laser.RESULTSThe quantitative model predicted that proton disproportionation of THAP would be achieved by thermal energy converted from a commonly used single UV laser photon. The dielectric effect reduced the reaction Gibbs free energy considerably even when the dielectric constant was reduced under high‐temperature MALDI conditions. With minimum fitting parameters, observations of pure THAP and THAP mixed with fullerene both agreed with predictions.CONCLUSIONSProton disproportionation of solid THAP was energetically favorable with a single UV laser photon. The quantitative model revealed an important initial ionization pathway induced by the abrupt heating of matrix crystals. In the matrix crystals, the dielectric effect reduced reaction Gibbs free energy under typical MALDI conditions. The result suggested that thermal energy plays an important role in the initial ionization reaction of THAP. Copyright © 2014 John Wiley & Sons, Ltd.
Novel design for non‐latency wireless binaural hearing aids
Authors: Wei Qun , Park Young Sik , Lee Seul Bi , Kim Dong Wook , Seong Ki Woong , Lee Jyung Hyun , Lee Seung‐Ha , Cho Jin‐Ho 
Published: June 2014

AbstractBinaural hearing aids consist of two hearing devices, one for each ear. A new concept of binaural hearing aids is proposed, in which only the master hearing aid contains a Bluetooth chip for receiving stereo audio signals from an external device, and the signal in one channel is sent to the slave hearing aid from the master by a 2.4‐GHz Gaussian frequency‐shift keying (GFSK) RF transmission method to create the binaural hearing effect. However, a problem arises in regard to the processing necessary for the signal transmission and reception in the two hearing aids, which creates a time delay that causes the precedence effect. Therefore, an audio delay processing algorithm has been designed in the master hearing aid to synchronize with the sound output of the slave hearing aid. Experimental results show that the time difference between the two hearing aids is about 8 µs, which is effective for avoiding the precedence effect. © 2014 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Why the Monte Carlo method is so important today
Authors: Kroese Dirk P. , Brereton Tim , Taimre Thomas , Botev Zdravko I. 
Published: June 2014

Since the beginning of electronic computing, people have been interested in carrying out random experiments on a computer. Such Monte Carlo techniques are now an essential ingredient in many quantitative investigations. Why is the Monte Carlo method (MCM) so important today? This article explores the reasons why the MCM has evolved from a ‘last resort’ solution to a leading methodology that permeates much of contemporary science, finance, and engineering. WIREs Comput Stat 2014, 6:386–392. doi: 10.1002/wics.1314This article is categorized under:

Statistical and Graphical Methods of Data Analysis > Markov Chain Monte Carlo (MCMC)
Statistical Models > Simulation Models
Preoperative Biliary Drainage of Severely Jaundiced Patients Increases Morbidity of Pancreaticoduodenectomy: Results of a Case‐Control Study
Authors: Arkadopoulos Nikolaos , Kyriazi Maria A. , Papanikolaou Ioannis S. , Vasiliou Pantelis , Theodoraki Kassiani , Lappas Christos , Oikonomopoulos Nikolaos , Smyrniotis Vassilios 
Published: June 2014

AbstractBackgroundRecent studies have indicated that preoperative biliary drainage (PBD) should not be routinely performed in patients suffering from obstructive jaundice before surgery. The severity of jaundice that mandates PBD has yet to be defined. Our aim was to investigate whether PBD is truly justified in severely jaundiced patients before pancreaticoduodenectomy. The parameters evaluated were overall morbidity, length of hospital stay, and total in‐hospital mortality.MethodsFrom January 2000 to December 2012, a total of 240 patients underwent pancreaticoduodenectomy for periampullary tumors. Group A comprised 76 patients with preoperative serum bilirubin ≥15 mg/dl who did not undergo PBD before surgery. Group B comprised another 76 patients, matched for age and tumor localization (papillary vs. pancreatic head) who underwent PBD 2–4 weeks before pancreaticoduodenectomy and were identified from the same database.ResultsLess operative time was required in the ‘no PBD’ group compared with the ‘PBD’ group (210 vs. 240 min). Total intraoperative blood loss and blood transfusions were also significantly less in the ‘no PBD’ group. There was no difference detected in the rate of pancreatic fistula or biliary fistula formation. Group A patients demonstrated significantly lower morbidity than group B (24 vs. 36 %, respectively) and therefore required briefer hospitalization (11 vs. 16 days). Mild infectious complications appear to be the main factor that enhanced morbidity in the PBD group. However, total in‐hospital mortality was not significantly different between the two groups.ConclusionsEven severe jaundice should not be considered as an indication for PBD before pancreaticoduodenectomy, as PBD increases infections and postoperative morbidity, therefore delaying definite treatment.
Feasibility of a Community Intervention for the Prevention of Suicide and Alcohol Abuse with Yup'ik Alaska Native Youth: The Elluam Tungiinun and Yupiucimta Asvairtuumallerkaa Studies
Authors: Mohatt Gerald V. , Fok Carlotta Ching Ting , Henry David , Allen James 
Published: June 2014

AbstractThe Elluam Tungiinun and Yupiucimta Asvairtuumallerkaa studies evaluated the feasibility of a community intervention to prevent suicide and alcohol abuse among rural Yup'ik Alaska Native youth in two remote communities. The intervention originated in an Indigenous model of protection, and its development used a community based participatory research process. Feasibility assessment aimed to assess the extent to which (1) the intervention could be implemented in rural Alaska Native communities, and (2) the intervention was capable of producing measurable effects. Scales maximally sensitive to change were derived from earlier measurement work, and the study contrasted implementation process and outcomes across the two communities. In one community, medium dose response effects (d = .30–.50), with dose defined as number of intervention activities attended, were observed in the growth of intermediate protective factors and ultimate variables. In the other community, medium dose effects were observed for one intermediate protective factor variable, and small dose effects were observed in ultimate variables. Differences across communities in resources supporting intervention explain these contrasting outcomes. Results suggest implementation in these rural Alaska settings is feasible when sufficient resources are available to sustain high levels of local commitment. In such cases, measureable effects are sufficient to warrant a prevention trial.
Neurotrophins: Role in adverse pregnancy outcome
Authors: Dhobale Madhavi 
Published: June 2014

AbstractProper placental development is essential during pregnancy since it forms the interface between the maternal–foetal circulations and is critical for foetal nutrition and oxygenation. Neurotrophins such as nerve growth factor (NGF), brain derived neurotrophin (BDNF), neurotrophin‐3 (NT‐3) and neurotrophin‐4/5 (NT‐4/5) are naturally occurring molecules that regulate development of the placenta and brain. BDNF and NGF also involved in the regulation of angiogenesis. Recent studies suggest that the levels of BDNF and NGF are regulated by docosahexaenoic acid (DHA) which is an important omega‐3 fatty acid and is a structural component of the plasma membrane. Oxidative stress during pregnancy may lower the levels of DHA and affecting the fluidity of the membranes leading to the changes in the levels and expression of BDNF and NGF. Therefore altered levels and expression of NGF and BDNF may lead to abnormal foetal growth and brain development that may increase the risk for cardiovascular disease, metabolic syndromes and neurodevelopmental disorders in children born preterm. This review discuss about the neurotrophins and their role in the feto‐placental unit during critical period of pregnancy.
Long-wave dynamics of an inextensible planar membrane in an electric field
Authors: Young Y.-N. , Veerapaneni Shravan , Miksis Michael J. 
Published: June 2014

AbstractIn this paper the dynamics of an inextensible capacitive elastic membrane under an electric field is investigated in the long-wave (lubrication) leaky dielectric framework, where a sixth-order nonlinear differential equation with an integral constraint is derived. Steady equilibrium profiles for a non-conducting membrane in a direct current (DC) field are found to depend only on the membrane excess area and the volume under the membrane. Linear stability analysis on a tensionless flat membrane in a DC field gives the growth rate in terms of membrane conductance and electric properties in the bulk. Numerical simulations of a capacitive conducting membrane under an alternating current (AC) field elucidate how variation of the membrane tension correlates with the nonlinear membrane dynamics. Different membrane dynamics, such as undulation and flip-flop, are found at different electric field strength and membrane area. In particular a travelling wave on the membrane is found as a response to a periodic AC field in the perpendicular direction.
Contested Colonialism: Responsible Government and Political Development in Yukon
Authors: Sabin Jerald 
Published: June 2014

AbstractThis article argues that the granting of responsible government to Yukon in 1979 was not the inevitable outcome of territorial political development but the result of a protracted and organized settler political movement that emerged first in opposition to the federal government and, later, to Yukon's Indigenous peoples. I analyze settler actor political behaviour and outcomes using the framework of “contested colonialism.” Non-Indigenous Yukoners are understood as actors who simultaneously bring colonialism to the North while also contesting elements of that same colonial order. Using extensive archival research, I identify several critical junctures leading to the implementation of responsible government during the 1960s and 1970s.
SHORT- TO MID-TERM IMPACT OF CONSERVATION AGRICULTURE ON YIELD VARIABILITY OF UPLAND RICE: EVIDENCE FROM FARMER’S FIELDS IN MADAGASCAR
Authors: BRUELLE GUILLAUME , NAUDIN KRISHNA , SCOPEL ERIC , DOMAS RAPHAËL , RABEHARISOA LILIA , TITTONELL PABLO 
Published: June 2014

SUMMARYFamily farming in the tropics suffers from low crop productivity mainly due to a combination of poor soil fertility, low investment capacity, and a variable climate. The Lake Alaotra region of Madagascar is no exception and rainfed production is particularly hard hit. To evaluate the agronomic benefits of conservation agriculture (CA) in a region of erratic rainfall, we analysed four years of yield, management and climatic data from 3803 upland rice fields cultivated by farmers and monitored by researchers. Fields located on rainfed lowlands and hillsides were cultivated with sole rice using conventional tillage (Cv) or rice sown with no-tillage on dead organic mulch and rotated with other cereal/legume combinations (CA) from 2006 to 2011. A first global comparison across seasons, locations and years of adoption showed significantly higher average yields under CA, with no change in variance (on lowland: 2.6 ± 0.9 t ha–1 Cv, 2.8 ± 0.9 t ha–1 CA; on hillside: 2.1 ± 0.8 t ha–1 Cv, 2.4 ± 0.8 t ha–1 CA). Grouping fields according to the number of years under CA (first to fourth) revealed that CA gradually increased average yields and reduced the coefficient of variation in the short and mid-term (on lowland: +0.2 t ha–1 and –6% coefficient of variation; on hillside: +0.7 t ha–1 and –13% coefficient of variation, over four to six years of successive CA cropping). The average yield increase under CA was not associated with an increase in mineral fertiliser use, as farmers used the same amounts of fertilisers (or none) under Cv and CA. The comparison Cv versus CA also highlighted a major benefit of CA regarding climate: it widened the window of possible sowing dates. A classification and regression tree analysis of the entire dataset revealed that rice yield was more affected by agro-environmental factors than management factors (fertilisation, Cv or CA), and extreme climate variability such as the severe drought of 2007–2008 could not be offset by CA. The hypothesis of yield penalties during the first years of implementation of CA cannot be verified with the evidence presented in this study.
Diet and feeding strategy of thornback ray,Raja clavata(Chondrichthyes: Rajidae) from the Gulf of Gabes (Tunisia—Central Mediterranean Sea)
Authors: Kadri Hasna , Marouani Sondes , Bradai Mohamed Nejmeddine , Bouaïn Abderrahmen 
Published: June 2014

Food and feeding strategy of the thornback ray,Raja clavata, were studied from stomach contents analysis of specimens caught monthly in the Gulf of Gabes. The data were analysed according to sex, size and season. At total of 1280 stomachs was examined, from specimens ranging from 14 to 110 cm total length (TL), of which 1076 (83.98%) contained food. Thornback ray feed mainly on teleosts, crustaceans and cephalopods, whereas gastropods and polychaetes are occasionally consumed. Significant differences were found between the diets of males and females; however, ontogenetic changes were also detected, with crustaceans constituting the greatest proportion of the diet of smaller rays. Both teleosts and cephalopods increased in importance with growth of the skates. Prey diversity increased with size; large and mobile prey species were more commonly found in the diet of larger skates. Diet composition showed seasonal variations. Quantitative analyses and graphical methods indicate that the thornback ray is a generalist feeder.
Higher population densities of the sea urchinDiadema antillarumlinked to wave sheltered areas in north Puerto Rico Archipelago
Authors: Rodríguez-Barreras Ruber , Pérez María E. , Mercado-Molina Alex E. , Williams Stacey M. , Sabat Alberto M. 
Published: June 2014

The long-spined sea urchinDiadema antillarumhas been the focus of multiple studies since the mass mortality event in the 1980s. The recovery of this key herbivore in the wider Caribbean is essential for the well-being of coral reefs. This study examined the population density and structure ofD. antillarumat seven northern fringing reefs of Puerto Rico between 2011 and 2013. The total mean density of the sea urchins in northern Puerto Rico was 0.9 ±0.3 ind m−2. Densities ofD. antillarumsignificantly differed among sites, but not temporally. Differences in mean sizes were significant among sites and seasons. Areas with higher densities ofD. antillarumshowed lower cover of non-calcareous algae. Wave exposure was correlated with the abundance of the sea urchin. This study indicates that the observed abundance ofD. antillarumhas not yet returned to pre-mortality levels. However, densities showed some degree of recovery when compared with previous studies, enabling at least some degree of control on fleshy macroalgae communities. No significant changes in density occurred between 2011 and 2013, and sites with higher densities were generally located in leeward areas. The low relative abundance of small size individuals points towards recruitment limitation as an explanation for the limited recovery ofD. antillarum.
Mental health in Dutch adolescents: a TRAILS report on prevalence, severity, age of onset, continuity and co-morbidity of DSM disorders
Authors: Ormel J. , Raven D. , van Oort F. , Hartman C. A. , Reijneveld S. A. , Veenstra R. , Vollebergh W. A. M. , Buitelaar J. , Verhulst F. C. , Oldehinkel A. J. 
Published: June 2014

BackgroundWith psychopathology rising during adolescence and evidence suggesting that adult mental health burden is often due to disorders beginning in youth, it is important to investigate the epidemiology of adolescent mental disorders.MethodWe analysed data gathered at ages 11 (baseline) and 19 years from the population-based Dutch TRacking Adolescents' Individual Lives Survey (TRAILS) study. At baseline we administered the Achenbach measures (Child Behavior Checklist, Youth Self-Report) and at age 19 years the World Health Organization's Composite International Diagnostic Interview version 3.0 (CIDI 3.0) to 1584 youths.ResultsLifetime, 12-month and 30-day prevalences of any CIDI-DSM-IV disorder were 45, 31 and 15%, respectively. Half were severe. Anxiety disorders were the most common but the least severe whereas mood and behaviour disorders were less prevalent but more severe. Disorders persisted, mostly by recurrence in mood disorders and chronicity in anxiety disorders. Median onset age varied substantially across disorders. Having one disorder increased subjects' risk of developing another disorder. We found substantial homotypic and heterotypic continuity. Baseline problems predicted the development of diagnosable disorders in adolescence. Non-intact families and low maternal education predicted externalizing disorders. Most morbidity concentrated in 5–10% of the sample, experiencing 34–55% of all severe lifetime disorders.ConclusionsAt late adolescence, 22% of youths have experienced a severe episode and 23% only mild episodes. This psychopathology is rather persistent, mostly due to recurrence, showing both monotypic and heterotypic continuity, with family context affecting particularly externalizing disorders. High problem levels at age 11 years are modest precursors of incident adolescent disorders. The burden of mental illness concentrates in 5–10% of the adolescent population.