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Showing papers by "Memorial University of Newfoundland published in 2007"


Journal ArticleDOI
02 Feb 2007-Science
TL;DR: The findings of these 12 FeAXs reveal that iron supply exerts controls on the dynamics of plankton blooms, which in turn affect the biogeochemical cycles of carbon, nitrogen, silicon, and sulfur and ultimately influence the Earth climate system.
Abstract: Since the mid-1980s, our understanding of nutrient limitation of oceanic primary production has radically changed. Mesoscale iron addition experiments (FeAXs) have unequivocally shown that iron supply limits production in one-third of the world ocean, where surface macronutrient concentrations are perennially high. The findings of these 12 FeAXs also reveal that iron supply exerts controls on the dynamics of plankton blooms, which in turn affect the biogeochemical cycles of carbon, nitrogen, silicon, and sulfur and ultimately influence the Earth climate system. However, extrapolation of the key results of FeAXs to regional and seasonal scales in some cases is limited because of differing modes of iron supply in FeAXs and in the modern and paleo-oceans. New research directions include quantification of the coupling of oceanic iron and carbon biogeochemistry.

1,269 citations


Journal ArticleDOI
TL;DR: The authors provide a comprehensive survey of different modulation recognition techniques in a systematic way, and simulated some major techniques under the same conditions, which allows a fair comparison among different methodologies.
Abstract: The automatic recognition of the modulation format of a detected signal, the intermediate step between signal detection and demodulation, is a major task of an intelligent receiver, with various civilian and military applications. Obviously, with no knowledge of the transmitted data and many unknown parameters at the receiver, such as the signal power, carrier frequency and phase offsets, timing information and so on, blind identification of the modulation is a difficult task. This becomes even more challenging in real-world scenarios with multipath fading, frequency-selective and time-varying channels. With this in mind, the authors provide a comprehensive survey of different modulation recognition techniques in a systematic way. A unified notation is used to bring in together, under the same umbrella, the vast amount of results and classifiers, developed for different modulations. The two general classes of automatic modulation identification algorithms are discussed in detail, which rely on the likelihood function and features of the received signal, respectively. The contributions of numerous articles are summarised in compact forms. This helps the reader to see the main characteristics of each technique. However, in many cases, the results reported in the literature have been obtained under different conditions. So, we have also simulated some major techniques under the same conditions, which allows a fair comparison among different methodologies. Furthermore, new problems that have appeared as a result of emerging wireless technologies are outlined. Finally, open problems and possible directions for future research are briefly discussed.

1,140 citations


Journal ArticleDOI
TL;DR: In this paper, the antioxidant activity and functional properties of protein hydrolysates from yellow stripe trevally (Selaroides leptolepis) meat, hydrolyzed by Alcalase 2.4L (HA) and Flavourzyme 500L (HF) with different degrees of hydrolysis (DH) were investigated.

857 citations


Journal ArticleDOI
TL;DR: A meta-analysis of 57 empirical studies concerning enacted workplace aggression shows that both individual and situational factors predict aggression and that the pattern of predictors is target specific.
Abstract: The authors conducted a meta-analysis of 57 empirical studies (59 samples) concerning enacted workplace aggression to answer 3 research questions. First, what are the individual and situational predictors of interpersonal and organizational aggression? Second, within interpersonal aggression, are there different predictors of supervisor- and coworker-targeted aggression? Third, what are the relative contributions of individual (i.e., trait anger, negative affectivity, and biological sex) and situational (i.e., injustice, job dissatisfaction, interpersonal conflict, situational constraints, and poor leadership) factors in explaining interpersonal and organizational aggression? Results show that both individual and situational factors predict aggression and that the pattern of predictors is target specific. Implications for future research are discussed.

835 citations


Journal ArticleDOI
TL;DR: Using a multistage genetic association approach comprising 7,480 affected individuals and 7,779 controls, markers in chromosomal region 8q24 associated with colorectal cancer were identified and this locus has been implicated in prostate cancer.
Abstract: Using a multistage genetic association approach comprising 7,480 affected individuals and 7,779 controls, we identified markers in chromosomal region 8q24 associated with colorectal cancer. In stage 1, we genotyped 99,632 SNPs in 1,257 affected individuals and 1,336 controls from Ontario. In stages 2-4, we performed serial replication studies using 4,024 affected individuals and 4,042 controls from Seattle, Newfoundland and Scotland. We identified one locus on chromosome 8q24 and another on 9p24 having combined odds ratios (OR) for stages 1-4 of 1.18 (trend; P = 1.41 x 10(-8)) and 1.14 (trend; P = 1.32 x 10(-5)), respectively. Additional analyses in 2,199 affected individuals and 2,401 controls from France and Europe supported the association at the 8q24 locus (OR = 1.16, trend; 95% confidence interval (c.i.): 1.07-1.26; P = 5.05 x 10(-4)). A summary across all seven studies at the 8q24 locus was highly significant (OR = 1.17, c.i.: 1.12-1.23; P = 3.16 x 10(-11)). This locus has also been implicated in prostate cancer.

739 citations


Journal ArticleDOI
TL;DR: The model embodies 4 main claims: temporal memory--traces of items are represented in memory partly in terms of their temporal distance from the present, scale-similarity--similar mechanisms govern retrieval from memory over many different timescales, local distinctiveness--performance on a range of memory tasks is determined by interference from near psychological neighbors, and interference-based forgetting.
Abstract: A model of memory retrieval is described. The model embodies 4 main claims: (a) temporal memory-traces of items are represented in memory partly in terms of their temporal distance from the present; (b) scale-similarity-similar mechanisms govern retrieval from memory over many different timescales; (c) local distinctiveness-performance, on a range of memory tasks is determined by interference from near psychological neighbors; and (d) interference-based forgetting-all memory loss is due to interference and not trace decay. The model is applied to data on free recall and serial recall. The account emphasizes qualitative similarity in the retrieval principles involved in memory performance at all timescales, contrary to models that emphasize distinctions between short-term and long-term memory.

673 citations


Journal ArticleDOI
TL;DR: It is suggested that strategic alliances serve an important legitimating function for firms and that this role, mediated by alliance governance structure and partner selection preferences, has a significant influence on firm and alliance performance.
Abstract: Drawing on an institutional perspective, this paper suggests that strategic alliances serve an important legitimating function for firms and that this role, mediated by alliance governance structure and partner selection preferences, has a significant influence on firm and alliance performance. A theoretical framework is proposed that identifies five types of legitimacy associated with strategic alliances and the specific conditions under which legitimation may be an important outcome of strategic alliances. Propositions are developed to explain when firms are most likely to enter into alliances for legitimacy purposes and how the legitimating role of strategic alliances contributes to firm and alliance performance. The paper concludes with a summary and implications of a legitimacy-based view of alliances. Copyright © 2007 John Wiley & Sons, Ltd.

659 citations


Journal ArticleDOI
TL;DR: In this article, the theory of asymptotic speeds of spread and monotone traveling waves is established for a class of discrete and continuous-time semlows and is applied to a functional differential equation with diffusion, a time-delayed lattice population model and a reaction-diffusion equation in an infinite cylinder.
Abstract: The theory of asymptotic speeds of spread and monotone traveling waves is established for a class of monotone discrete and continuous-time semiflows and is applied to a functional differential equation with diffusion, a time-delayed lattice population model and a reaction-diffusion equation in an infinite cylinder. c � 2006 Wiley Periodicals, Inc.

623 citations


Journal ArticleDOI
TL;DR: The combined data provide support that haploinsufficiency of SHANK3 can cause a monogenic form of autism in sufficient frequency to warrant consideration in clinical diagnostic testing.
Abstract: Mutations in SHANK3, which encodes a synaptic scaffolding protein, have been described in subjects with an autism spectrum disorder (ASD). To assess the quantitative contribution of SHANK3 to the pathogenesis of autism, we determined the frequency of DNA sequence and copy-number variants in this gene in 400 ASD-affected subjects ascertained in Canada. One de novo mutation and two gene deletions were discovered, indicating a contribution of 0.75% in this cohort. One additional SHANK3 deletion was characterized in two ASD-affected siblings from another collection, which brings the total number of published mutations in unrelated ASD-affected families to seven. The combined data provide support that haploinsufficiency of SHANK3 can cause a monogenic form of autism in sufficient frequency to warrant consideration in clinical diagnostic testing.

622 citations


Journal ArticleDOI
TL;DR: This letter analyzes the performance of cooperative diversity wireless networks using amplify-and-forward relaying over independent, non-identical, Nakagami-m fading channels and shows that the derived error rate and outage probability are tight lower bounds particularly at medium and high SNR.
Abstract: This letter analyzes the performance of cooperative diversity wireless networks using amplify-and-forward relaying over independent, non-identical, Nakagami-m fading channels. The error rate and the outage probability are determined using the moment generating function (MGF) of the total signal-to-noise-ratio (SNR) at the destination. Since it is hard to find a closed form for the probability density function (PDF) of the total SNR, we use an approximate value instead. We first derive the PDF and the MGF of the approximate value of the total SNR. Then, the MGF is used to determine the error rate and the outage probability. We also use simulation to verify the analytical results. Results show that the derived error rate and outage probability are tight lower bounds particularly at medium and high SNR

513 citations


Journal ArticleDOI
TL;DR: In this paper, the authors present an overview of the key characteristics of small-scale coastal marine fisheries in Latin America and the Caribbean as well as an examination of some of the weaknesses, gaps, and challenges faced in fisheries assessment and management within the region.

Journal ArticleDOI
TL;DR: To enhance comparability of findings among studies, species, and oceanographic regions, a recommendation on standards for the reporting of results in the literature is made.
Abstract: We review the different methods that are used to collect dietary data from marine birds. We consider their limitations and practicalities and emphasize critical data gaps in our knowledge of the feeding ecology of seabirds (na mely diets outside breeding seasons). To enhance comparability of findings among studies, species, and oceanographic regions, we make recommendations on standards for the reporting of results in the literature.

Journal ArticleDOI
TL;DR: In this paper, the authors used bounce-averaged quasi-linear diffusion coefficients for field-aligned waves with a Gaussian frequency spectrum in a dipole magnetic field to evaluate timescales for electron momentum diffusion and pitch angle diffusion, and confirmed that chorus diffusion is a viable mechanism for generating relativistic (MeV) electrons in the outer zone during the recovery phase of a storm or during periods of prolonged substorm activity when chorus amplitudes are enhanced.
Abstract: Outer zone radiation belt electrons can undergo gyroresonant interaction with various magnetospheric wave modes including whistler-mode chorus outside the plasmasphere and both whistler-mode hiss and electromagnetic ion cyclotron (EMIC) waves inside the plasmasphere. To evaluate timescales for electron momentum diffusion and pitch angle diffusion, we utilize bounce-averaged quasi-linear diffusion coefficients for field-aligned waves with a Gaussian frequency spectrum in a dipole magnetic field. Timescales for momentum diffusion of MeV electrons due to VLF chorus can be less than a day in the outer radiation belt. Equatorial chorus waves (|λw| < 15 deg) can effectively accelerate MeV electrons. Efficiency of the chorus acceleration mechanism is increased if high-latitude waves (|λw| < 15 deg) are also present. Our calculations confirm that chorus diffusion is a viable mechanism for generating relativistic (MeV) electrons in the outer zone during the recovery phase of a storm or during periods of prolonged substorm activity when chorus amplitudes are enhanced. Radiation belt electrons are subject to precipitation loss to the atmosphere due to resonant pitch angle scattering by plasma waves. The electron precipitation loss timescale due to scattering by each of the wave modes, chorus, hiss, and EMIC waves, can be 1 day or less. These wave modes can separately, or in combination, contribute significantly to the depletion of relativistic (MeV) electrons from the outer zone over the course of a magnetic storm. Efficient pitch angle scattering by whistler-mode chorus or hiss typically requires high latitude waves (|λw| < 30 deg). Timescales for electron acceleration and loss generally depend on the spectral properties of the waves, as well as the background electron number density and magnetic field. Loss timescales due to EMIC wave scattering also depend on the ion (H+, He+, O+) composition of the plasma. Complete models of radiation belt electron transport, acceleration and loss should include, in addition to radial (cross-L) diffusion, resonant diffusion due to gyroresonance with VLF chorus, plasmaspheric hiss, and EMIC waves. Comprehensive observational data on the spectral properties of these waves are required as a function of spatial location (L, MLT, MLAT) and magnetic activity.

Journal ArticleDOI
06 Jun 2007-JAMA
TL;DR: Recurrent CDH1 mutations in families with hereditary diffuse gastric cancer are due to both independent mutational events and common ancestry, and the presence of a founder mutation from Newfoundland is strongly supported.
Abstract: ContextHereditary diffuse gastric cancer is caused by germline mutations in the epithelial cadherin (CDH1) gene and is characterized by an increased risk for diffuse gastric cancer and lobular breast cancer.ObjectiveTo determine whether recurring germline CDH1 mutations occurred due to independent mutational events or common ancestry.Design, Setting, and PatientsThirty-eight families diagnosed clinically with hereditary diffuse gastric cancer were accrued between November 2004 and January 2006 and were analyzed for CDH1 mutations as part of an ongoing study at the British Columbia Cancer Agency. Twenty-six families had at least 2 gastric cancer cases with 1 case of diffuse gastric cancer in a person younger than 50 years; 12 families had either a single case of diffuse gastric cancer diagnosed in a person younger than 35 years or multiple cases of diffuse gastric cancer diagnosed in persons older than 50 years.Main Outcome MeasuresClassification of family members as carriers or noncarriers of CDH1 mutations. Haplotype analysis to assess recurring mutations for common ancestry was performed on 7 families from this study and 7 previously reported families with the same mutations.ResultsThirteen mutations (6 novel) were identified in 15 of the 38 families (40% detection rate). The 1137G>A splicing mutation and the 1901C>T (A634V) missense/splicing mutation occurred on common haplotypes in 2 families but on different haplotypes in a third family. The 2195G>A (R732Q) missense/splicing mutation occurred in 2 families on different haplotypes. The 2064-2065delTG mutation occurred on a common haplotype in 2 families. Two families from this study plus 2 additional families carrying the novel 2398delC mutation shared a common haplotype, suggesting a founder effect. All 4 families originate from the southeast coast of Newfoundland. Due to concentrations of lobular breast cancer cases, 2 branches of this family had been diagnosed as having hereditary breast cancer and were tested for BRCA mutations. Within these 4 families, the cumulative risk by age 75 years in mutation carriers for clinically detected gastric cancer was 40% (95% confidence interval [CI], 12%-91%) for males and 63% (95% CI, 19%-99%) for females and the risk for breast cancer in female mutation carriers was 52% (95% CI, 29%-94%).ConclusionsRecurrent CDH1 mutations in families with hereditary diffuse gastric cancer are due to both independent mutational events and common ancestry. The presence of a founder mutation from Newfoundland is strongly supported.Published online June 3, 2007 (doi:10.1001/jama.297.21.2360).

Journal ArticleDOI
TL;DR: In this article, the composition, functional properties and antioxidative activity of a protein hydrolysate prepared from defatted round scad (Decapterus maruadsi) mince using Flavourzyme, with a degree of hydrolysis (DH) of 60%, were determined.

Journal ArticleDOI
TL;DR: In patients with peripheral arterial disease, the combination of an oral anticoagulant and antiplatelet therapy was not more effective than anti platelet therapy alone in preventing major cardiovascular complications and was associated with an increase in life-threatening bleeding.
Abstract: Background Atherosclerotic peripheral arterial disease is associated with an increased risk of myocardial infarction, stroke, and death from cardiovascular causes. Antiplatelet drugs reduce this risk, but the role of oral anticoagulant agents in the prevention of cardiovascular complications in patients with peripheral arterial disease is unclear. Methods We assigned patients with peripheral arterial disease to combination therapy with an antiplatelet agent and an oral anticoagulant agent (target international normalized ratio [INR], 2.0 to 3.0) or to antiplatelet therapy alone. The first coprimary outcome was myocardial infarction, stroke, or death from cardiovascular causes; the second coprimary outcome was myocardial infarction, stroke, severe ischemia of the peripheral or coronary arteries leading to urgent intervention, or death from cardiovascular causes. Results A total of 2161 patients were randomly assigned to therapy. The mean follow-up time was 35 months. Myocardial infarction, stroke, or death from cardiovascular causes occurred in 132 of 1080 patients receiving combination therapy (12.2%) and in 144 of 1081 patients receiving antiplatelet therapy alone (13.3%) (relative risk, 0.92; 95% conf idence interval [CI], 0.73 to 1.16; P = 0.48). Myocardial infarction, stroke, severe ischemia, or death from cardiovascular causes occurred in 172 patients receiving combination therapy (15.9%) as compared with 188 patients receiving antiplatelet therapy a lone (17.4%) (relative risk, 0.91; 95% CI, 0.74 to 1.12; P = 0.37). Life-threatening bleeding occurred in 43 patients receiving combination therapy (4.0%) as compared with 13 patients receiving antiplatelet therapy alone (1.2%) (relative risk, 3.41; 95% CI, 1.84 to 6.35; P<0.001). Conclusions In patients with peripheral arterial disease, the combination of an oral anticoagulant and antiplatelet therapy was not more effective than antiplatelet therapy alone in preventing major cardiovascular complications and was associated with an increase in life-threatening bleeding. (ClinicalTrials.gov number, NCT00125671.)

Journal ArticleDOI
TL;DR: In this article, the authors argue that service loyalty is similar to loyalty in interpersonal relationships, providing further evidence for the notion that service provider-consumer relationships can approximate friendships or even romantic partnerships in terms of loyalty like responses.
Abstract: Purpose – The majority of research in marketing now represents loyalty as a multi‐dimensional construct; however, agreement on whether it has two or three dimensions is lacking, and measurement of these dimensions has been inconsistent. The purpose of this paper is to utilize theory from the psychology literature on interpersonal relationships to provide theoretical guidance for examining the nature of service loyalty and to uncover its dimensionality.Design/methodology/approach – This paper argues for and tests, using survey data from over 300 service customers, a multi‐dimensional conceptualization of loyalty based on theory from the interpersonal psychology literature.Findings – The findings of this research highlight that service loyalty is similar to loyalty in interpersonal relationships, providing further evidence for the notion that service provider‐consumer relationships can approximate friendships or even romantic partnerships in terms of loyalty‐like responses. It also suggests that to identify...

Journal ArticleDOI
TL;DR: Results suggest that hazelnut byproducts could potentially be considered as an excellent and readily available source of natural antioxidants.
Abstract: Antioxidant efficacies of ethanol extracts of defatted raw hazelnut kernel and hazelnut byproducts (skin, hard shell, green leafy cover, and tree leaf) were evaluated by monitoring total antioxidant activity (TAA) and free-radical scavenging activity tests [hydrogen peroxide, superoxide radical, and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical], together with antioxidant activity in a β-carotene−linoleate model system, inhibition of oxidation of human low-density lipoprotein (LDL) cholesterol, and inhibition of strand breaking of supercoiled deoxyribonucleic acid (DNA). In addition, yield, content of phenolics, and phenolic acid profiles (free and esterified fractions) were also examined. Generally, extracts of hazelnut byproducts (skin, hard shell, green leafy cover, and tree leaf) exhibited stronger activities than hazelnut kernel at all concentrations tested. Hazelnut extracts examined showed different antioxidative efficacies, expected to be related to the presence of phenolic compounds. Among samples...

Journal ArticleDOI
13 Sep 2007-Nature
TL;DR: Estimates of sea surface temperatures that were obtained from fossil brachiopod and mollusc shells using the ‘carbonate clumped isotope’ method are presented, consistent with the proposal that increased atmospheric carbon dioxide concentrations drive or amplify increased global temperatures.
Abstract: Atmospheric carbon dioxide concentrations seem to have been several times modern levels during much of the Palaeozoic era (543–248 million years ago), but decreased during the Carboniferous period to concentrations similar to that of today. Given that carbon dioxide is a greenhouse gas, it has been proposed that surface temperatures were significantly higher during the earlier portions of the Palaeozoic era. A reconstruction of tropical sea surface temperatures based on the δ^(18)O of carbonate fossils indicates, however, that the magnitude of temperature variability throughout this period was small, suggesting that global climate may be independent of variations in atmospheric carbon dioxide concentration. Here we present estimates of sea surface temperatures that were obtained from fossil brachiopod and mollusc shells using the 'carbonate clumped isotope' method—an approach that, unlike the δ^(18)O method, does not require independent estimates of the isotopic composition of the Palaeozoic ocean. Our results indicate that tropical sea surface temperatures were significantly higher than today during the Early Silurian period (443–423 Myr ago), when carbon dioxide concentrations are thought to have been relatively high, and were broadly similar to today during the Late Carboniferous period (314–300 Myr ago), when carbon dioxide concentrations are thought to have been similar to the present-day value. Our results are consistent with the proposal that increased atmospheric carbon dioxide concentrations drive or amplify increased global temperatures.

Journal ArticleDOI
TL;DR: It is evident that creatine plays a critical, though underappreciated, role in brain function.
Abstract: Creatine and phosphocreatine serve not only as an intracellular buffer for adenosine triphosphate, but also as an energy shuttle for the movement of high-energy phosphates from mitochondrial sites of production to cytoplasmic sites of utilization. The spontaneous loss of creatine and of phosphocreatine to creatinine requires that creatine be continuously replaced; this occurs by a combination of diet and endogenous synthesis. Vegetarians obtain almost no dietary creatine. Creatine synthesis makes major demands on the metabolism of glycine, arginine, and methionine. Large doses of creatine monohydrate are widely taken, particularly by athletes, as an ergogenic supplement; creatine supplements are also taken by patients suffering from gyrate atrophy, muscular dystrophy, and neurodegenerative diseases. Children with inborn errors of creatine synthesis or transport present with severe neurological symptoms and a profound depletion of brain creatine. It is evident that creatine plays a critical, though underappreciated, role in brain function.

Journal ArticleDOI
TL;DR: In this paper, bounce-averaged quasi-linear diffusion coefficients for field-aligned electromagnetic waves in a hydrogen or multi-ion (H+, He+, O+) plasma were derived.
Abstract: [1] Radiation belt electrons can interact with various modes of plasma wave in their drift orbits about the Earth, including whistler-mode chorus outside the plasmasphere, and both whistler-mode hiss and electromagnetic ion cyclotron waves inside the plasmasphere. Electrons undergo gyroresonant diffusion in their interactions with these waves. To determine the timescales for electron momentum diffusion and pitch angle diffusion, we develop bounce-averaged quasi-linear resonant diffusion coefficients for field-aligned electromagnetic waves in a hydrogen or multi-ion (H+, He+, O+) plasma. We assume that the Earth's magnetic field is dipolar and that the wave frequency spectrum is Gaussian. Evaluation of the diffusion coefficients requires the solution of a sixth-order polynomial equation for the resonant wave frequencies in the case of a multi-ion (H+, He+, O+) plasma, compared to the solution of a fourth-order polynomial equation for a hydrogen plasma. In some cases, diffusion coefficients for field-aligned waves can provide a valuable approximation for diffusion rates for oblique waves calculated using higher-order resonances. Bounce-averaged diffusion coefficients for field-aligned waves can be evaluated generally in minimal CPU time and can therefore be profitably incorporated into comprehensive kinetic radiation belt codes.

Journal ArticleDOI
TL;DR: This work measured standard and maximal metabolism in three marine fish species over their entire life history, and shows that while aerobic scope depends greatly on body size and developmental trajectory, it is extremely small during the early life stages (factorial aerobic scope ≤1.5).
Abstract: Fish larvae are the world's smallest vertebrates, and their high rates of mortality may be partially owing to a very limited aerobic scope. Unfortunately, however, no complete empirical dataset exists on the relationship between minimal and maximal metabolism (and thus aerobic scope) for any fish species throughout ontogeny, and thus such an association is hard to delineate. We measured standard and maximal metabolism in three marine fish species over their entire life history, and show that while aerobic scope depends greatly on body size and developmental trajectory, it is extremely small during the early life stages (factorial aerobic scope≤1.5). Our findings strongly suggest that limited scope for aerobic activity early in life is likely to constrain physiological function and ultimately impact behaviour and possibly survival. Furthermore, our results have important implications for ecological models that incorporate metabolic scaling, and provide additional evidence against the existence of ‘universal’ scaling exponents.

Journal ArticleDOI
TL;DR: In this article, the relativistic turning acceleration (RTA) was proposed for accelerating high-energy electrons by coherent whistler mode waves in the Earth's dipole magnetic field.
Abstract: [1] We report a very efficient process for accelerating high-energy electrons by coherent whistler mode waves in the Earth's dipole magnetic field, which we have found in our recent test particle simulations. The efficient acceleration process takes place for weakly relativistic seed electrons of a few hundred kiloelectronvolts. Under an assumption that the whistler mode wave packets are excited near the equatorial plane of the inner magnetosphere and propagate away from the equator, the acceleration process becomes irreversible. With a sufficiently long whistler mode wave packet of the order of 1 s, the energetic electrons are accelerated to a relativistic energy range of a few megaelectronvolts through a single resonant trapping process. We call this particular acceleration process relativistic turning acceleration (RTA), which could be a viable mechanism for increasing relativistic electron fluxes in the outer radiation belt. Necessary conditions for RTA are a relatively large amplitude of whistler mode waves, in the range of 50 to a few hundred picoteslas, and an initial kinetic energy of trapped electrons in the energy range of a few hundred kiloelectronvolts. The minimum energy of electrons accelerated by the RTA process and the maximum energy attained by it are derived analytically and verified by the test particle simulations.

Journal ArticleDOI
TL;DR: In women with renal insufficiency, the presence of both GFR less than 40 mL/min/1.73 m(2) and proteinuria with protein greater than 1 g/d before conception predicts poor maternal and fetal outcomes.

Journal ArticleDOI
TL;DR: In this paper, an epidemic model in a patchy environment with periodic coefficients is investigated, and the conditions under which the positive periodic solution is globally asymptotically stable.

Journal ArticleDOI
TL;DR: Tunable control of interparticle interactions in colloids will enable quantitative studies of phase transition kinetics as well as the creation of advanced materials with switchability of function and properties.
Abstract: Systems of spherical colloidal particles mimic the thermodynamics of atomic crystals. Control of interparticle interactions in colloids, which has recently begun to be extensively exploited, gives rise to rich phase behaviours as well as crystal structures with nanoscale and micron-scale lattice spacings. This provides model systems in which to study fundamental problems in condensed matter physics, such as the dynamics of crystal nucleation and melting, and the nature of the glass transition, at experimentally accessible lengthscales and timescales. Tunable control of these interactions provides reversible control. This will enable quantitative studies of phase transition kinetics as well as the creation of advanced materials with switchability of function and properties.

Journal ArticleDOI
TL;DR: In this article, the authors argue that what precedes the implementation of co-management is as important as what happens later in the process, and they pose questions about how the idea was conceived, who participated in the initial discussion, and the preparation required before implementation.

Journal ArticleDOI
TL;DR: The genomic sequence data that are currently available are used to identify candidate GTA-producing species and an evolutionary scheme for RcGTA-like elements in the α-proteobacteria is proposed.

Journal ArticleDOI
TL;DR: This paper identifies a set of QoS metrics in the context of WS workflows, and proposes a unified probabilistic model for describing QoS values of a broader spectrum of atomic and composite Web services.

Journal ArticleDOI
TL;DR: The T allele of VEGF in +936 may act as a protective allele in the development of PsA and further studies regarding the role of pro-angiogenic markers in PsA are warranted.
Abstract: Angiogenesis appears to be a first-order event in psoriatic arthritis (PsA). Among angiogenic factors, the cytokines vascular endothelial growth factor (VEGF), epidermal growth factor (EGF), and fibroblast growth factors 1 and 2 (FGF1 and FGF2) play a central role in the initiation of angiogenesis. Most of these cytokines have been shown to be upregulated in or associated with psoriasis, rheumatoid arthritis (RA) or ankylosing spondylitis (AS). As these diseases share common susceptibility associations with PsA, investigation of these angiogenic factors is warranted. Two hundred and fifty-eight patients with PsA and 154 ethnically matched controls were genotyped using a Sequenom chip-based MALDI-TOF mass spectrometry platform. Four SNPs in the VEGF gene, three SNPs in the EGF gene and one SNP each in FGF1 and FGF2 genes were evaluated. Statistical analysis was performed using Fisher's exact test, and the Cochrane-Armitage trend test. Associations with haplotypes were estimated by using weighted logistic models, where the individual haplotype estimates were obtained using Phase v2.1. We have observed an increased frequency in the T allele of VEGF +936 (rs3025039) in control subjects when compared to our PsA patients [Fisher's exact p-value = 0.042; OR 0.653 (95% CI: 0.434, 0.982)]. Haplotyping of markers revealed no significant associations. The T allele of VEGF in +936 may act as a protective allele in the development of PsA. Further studies regarding the role of pro-angiogenic markers in PsA are warranted.