bluuebunny/crossref_metadata_2025 huggingface dataset:
Time for a rethink: time sub‐sampling methods in disparity‐through‐time analyses
Authors: Guillerme Thomas , Cooper Natalie
Published: April 2018

Disparity‐through‐time analyses can be used to determine how morphological diversity changes in response to mass extinctions, or to investigate the drivers of morphological change. These analyses are routinely applied to palaeobiological datasets, yet, although there is much discussion about how to best calculate disparity, there has been little consideration of how taxa should be sub‐sampled through time. Standard practice is to group taxa into discrete time bins, often based on stratigraphic periods. However, this can introduce biases when bins are of unequal size, and implicitly assumes a punctuated model of evolution. In addition, many time bins may have few or no taxa, meaning that disparity cannot be calculated for the bin and making it harder to complete downstream analyses. Here we describe a different method to complement the disparity‐through‐time tool‐kit: time‐slicing. This method uses a time‐calibrated phylogenetic tree to sample disparity‐through‐time at any fixed point in time rather than binning taxa. It uses all available data (tips, nodes and branches) to increase the power of the analyses, specifies the implied model of evolution (punctuated or gradual), and is implemented in R. We test the time‐slicing method on four example datasets and compare its performance in common disparity‐through‐time analyses. We find that the way we time sub‐sample taxa can change our interpretations of the results of disparity‐through‐time analyses. We advise using multiple methods for time sub‐sampling taxa, rather than just time binning, to gain a better understanding disparity‐through‐time.
Impact of foliar nickel application on urease activity, antioxidant metabolism and control of powdery mildew (Microsphaera diffusa) in soybean plants
Authors: Barcelos J. P. Q. , Reis H. P. G. , Godoy C. V. , Gratão P. L. , Furlani Junior E. , Putti F. F. , Campos M. , Reis A. R.
Published: April 2018

Nickel (Ni) is a cofactor for urease, an enzyme that breaks down urea into ammonia and carbon dioxide. This study aimed to evaluate the physiological impact of Ni on urea, antioxidant metabolism and powdery mildew severity in soybean plants. Seven levels of Ni (0, 10, 20, 40, 60, 80 and 100 g ha−1) alone or combined with the fungicides fluxapyroxad and pyraclostrobin were applied to soybean plants. The total Ni concentration ranged from 3.8 to 38.0 mg kg−1 in leaves and 3.0 to 18.0 mg kg−1 in seeds. A strong correlation was observed between Ni concentration in the leaves and seeds, indicating translocation of Ni from leaves to seeds. Application of Ni above 60 g ha−1 increased lipid peroxidation in the leaf tissues, indicative of oxidative stress. Application of 40 g ha−1 Ni combined with 300 mL ha−1 of fungicide reduced powdery mildew severity by up to 99%. Superoxide dismutase, catalase, peroxidase and urease enzyme activity were greatest under these conditions. Urea concentration decreased in response to Ni application. Urease activity in soybean leaves showed a negative correlation with powdery mildew severity. The leaf Ni concentration showed a positive correlation with the urease and a negative correlation with powdery mildew severity. The results of this study suggest that urease is a key enzyme regulated by Ni and has a role in host defence against powdery mildew by stimulating antioxidant metabolism in soybean plants.
The politics of credit claiming: Rights and recognition in health policy feedback
Authors: Burlacu Diana , Immergut Ellen M. , Oskarson Maria , Rönnerstrand Björn
Published: April 2018

Why do governments recognize rights? In this article, we rely on natural experiments and an innovative matching technique to identify a new causal mechanism of policy feedback, which we refer to as the “recognition” effect. We rely on the “hard case” of health care to demonstrate that attitudes towards the health system change in response to government policy change and, indeed, even to rights‐based initiatives. During the time when public opinion surveys on public satisfaction with the health system were in the field, governments in both Germany and Sweden introduced a new right: the right to a maximum waiting time for health services. This serendipity allowed us to compare respondents' attitudes both before (control) and after the implementation of the waiting time guarantee (treatment), using coarsened exact matching to account for the imbalances in the treatment and control groups. We find that respondents interviewed after implementation of the new waiting time guarantees (in contrast to those interviewed before the introduction of the guarantees) express higher levels of satisfaction with the health system in general, but do not evaluate their specific medical treatment (including waiting times) more positively. We interpret this finding as evidence that citizens respond to governmental recognition of their rights as a good per se, independent of their personal experience with the particular public service at hand. Thus, we argue that theories of policy feedback need to move beyond their focus on direct material experience with the policies at hand, and to incorporate mechanisms of symbolic action and normative valuations into their causal models.
Camptotheca acuminata 10‐hydroxycamptothecin O‐methyltransferase: an alkaloid biosynthetic enzyme co‐opted from flavonoid metabolism
Authors: Salim Vonny , Jones A. Daniel , DellaPenna Dean
Published: April 2018

The medicinal plant Camptotheca acuminata accumulates camptothecin, 10‐hydroxycamptothecin, and 10‐methoxycamptothecin as its major bioactive monoterpene indole alkaloids. Here, we describe identification and functional characterization of 10‐hydroxycamptothecin O‐methyltransferase (Ca10OMT), a member of the Diverse subclade of class II OMTs. Ca10OMT is highly active toward both its alkaloid substrate and a wide range of flavonoids in vitro and in this way contrasts with other alkaloid OMTs in the subclade that only utilize alkaloid substrates. Ca10OMT shows a strong preference for the A‐ring 7‐OH of flavonoids, which is structurally equivalent to the 10‐OH of 10‐hydroxycamptothecin. The substrates of other alkaloid OMTs in the subclade bear little similarity to flavonoids, but the 3‐D positioning of the 7‐OH, A‐ and C‐rings of flavonoids is nearly identical to the 10‐OH, A‐ and B‐rings of 10‐hydroxycamptothecin. This structural similarity likely explains the retention of flavonoid OMT activity by Ca10OMT and also why kaempferol and quercetin aglycones are potent inhibitors of its 10‐hydroxycamptothecin activity. The catalytic promiscuity and strong inhibition of Ca10OMT by flavonoid aglycones in vitro prompted us to investigate the potential physiological roles of the enzyme in vivo. Based on its regioselectivity, kinetic parameters and absence of 7‐OMT flavonoids in vivo, we conclude that the major and likely only substrate of Ca10OMTin vivo is 10‐hydroxycamptothecin. This is likely accomplished by Ca10OMT being kept spatially separated at the tissue levels from potentially inhibitory flavonoid aglycones, and flavonoid aglycones being rapidly glycosylated to non‐inhibitory flavonoid glycosides.
EARLY STARVATION1 specifically affects the phosphorylation action of starch‐related dikinases
Authors: Malinova Irina , Mahto Harendra , Brandt Felix , AL‐Rawi Shadha , Qasim Hadeel , Brust Henrike , Hejazi Mahdi , Fettke Joerg
Published: April 2018

Starch phosphorylation by starch‐related dikinases glucan, water dikinase (GWD) and phosphoglucan, water dikinase (PWD) is a key step in starch degradation. Little information is known about the precise structure of the glucan substrate utilized by the dikinases and about the mechanisms by which these structures may be influenced. A 50‐kDa starch‐binding protein named EARLY STARVATION1 (ESV1) was analyzed regarding its impact on starch phosphorylation. In various in vitro assays, the influences of the recombinant protein ESV1 on the actions of GWD and PWD on the surfaces of native starch granules were analyzed. In addition, we included starches from various sources as well as truncated forms of GWD. ESV1 preferentially binds to highly ordered, α‐glucans, such as starch and crystalline maltodextrins. Furthermore, ESV1 specifically influences the action of GWD and PWD at the starch granule surface. Starch phosphorylation by GWD is decreased in the presence of ESV1, whereas the action of PWD increases in the presence of ESV1. The unique alterations observed in starch phosphorylation by the two dikinases are discussed in regard to altered glucan structures at the starch granule surface.
Identification and characterisation of a previously unknown drought tolerance‐associated microRNA in barley
Authors: Zhou Hui , Hussain Syed S. , Hackenberg Michael , Bazanova Natalia , Eini Omid , Li Jie , Gustafson Perry , Shi Bujun
Published: April 2018

Drought is the most serious abiotic stress, and causes crop losses on a worldwide scale. The present study identified a previously unknown microRNA (designated as hvu‐miRX) of 21 nucleotides (nt) in length in barley. Its precursor (designated pre‐miRX) and primary transcript (designated pri‐miRX) were also identified, with lengths of 73 and 559 nt, respectively. The identified upstream sequence of pri‐miRX contained both the TATA box and the CAAT box, which are both required for initiation of transcription. Transient promoter activation assays showed that the core promoter region of pri‐miRX ranged 500 nt from the transcription start site. In transgenic barley overexpression of the wheat DREB3 transcription factor (TaDREB3) caused hvu‐miRX to be highly expressed as compared with the same miRNA in non‐transgenic barley. However, the high expression was not directly associated with TaDREB3. Genomic analysis revealed that the hvu‐miRX gene was a single copy located on the short arm of chromosome 2 and appeared to be only conserved in Triticeae, but not in other plant species. Notably, transgenic barley that overexpressed hvu‐miRX showed drought tolerance. Degradome library analysis and other tests showed that hvu‐miRX targeted various genes including transcription factors via the cleavage mode. Our data provides an excellent opportunity to develop drought stress tolerant cereals using hvu‐miRX.
A cytological approach to studying meiotic recombination and chromosome dynamics in Arabidopsis thaliana male meiocytes in three dimensions
Authors: Hurel Aurélie , Phillips Dylan , Vrielynck Nathalie , Mézard Christine , Grelon Mathilde , Christophorou Nicolas
Published: April 2018

During meiotic prophase I chromosomes undergo dramatic conformational changes that accompany chromosome condensation, pairing and recombination between homologs. These changes include the anchoring of telomeres to the nuclear envelope and their clustering to form a bouquet. In plants, these events have been studied and illustrated in intact meiocytes of species with large genomes. Arabidopsis thaliana is an excellent genetic model in which major molecular pathways that control synapsis and recombination between homologs have been uncovered. Yet the study of chromosome dynamics is hampered by current cytological methods that disrupt the three‐dimensional (3D) architecture of the nucleus. Here we set up a protocol to preserve the 3D configuration of A. thaliana meiocytes. We showed that this technique is compatible with the use of a variety of antibodies that label structural and recombination proteins and were able to highlight the presence of clustered synapsis initiation centers at the nuclear periphery. By using fluorescence in situ hybridization we also studied the behavior of chromosomes during pre‐meiotic G2 and prophase I, revealing the existence of a telomere bouquet during A. thaliana male meiosis. In addition we showed that the number of telomeres in a bouquet and its volume vary greatly, thus revealing the complexity of telomere behavior during meiotic prophase I. Finally, by using probes that label subtelomeric regions of individual chromosomes, we revealed differential localization behaviors of chromosome ends. Our protocol opens new areas of research for investigating chromosome dynamics in A. thaliana meiocytes.
Chromosome‐scale pseudomolecules refined by optical, physical and genetic maps in flax
Authors: You Frank M. , Xiao Jin , Li Pingchuan , Yao Zhen , Jia Gaofeng , He Liqiang , Zhu Tingting , Luo Ming‐Cheng , Wang Xiue , Deyholos Michael K. , Cloutier Sylvie
Published: April 2018

Genomes of varying sizes have been sequenced with next‐generation sequencing platforms. However, most reference sequences include draft unordered scaffolds containing chimeras caused by mis‐scaffolding. A BioNano genome (BNG) optical map was constructed to improve the previously sequenced flax genome (Linum usitatissimum L., 2n = 30, about 373 Mb), which consisted of 3852 scaffolds larger than 1 kb and totalling 300.6 Mb. The high‐resolution BNG map of cv. CDC Bethune totalled 317 Mb and consisted of 251 BNG contigs with an N50 of 2.15 Mb. A total of 622 scaffolds (286.6 Mb, 94.9%) aligned to 211 BNG contigs (298.6 Mb, 94.2%). Of those, 99 scaffolds, diagnosed to contain assembly errors, were refined into 225 new scaffolds. Using the newly refined scaffold sequences and the validated bacterial artificial chromosome‐based physical map of CDC Bethune, the 211 BNG contigs were scaffolded into 94 super‐BNG contigs (N50 of 6.64 Mb) that were further assigned to the 15 flax chromosomes using the genetic map. The pseudomolecules total about 316 Mb, with individual chromosomes of 15.6 to 29.4 Mb, and cover 97% of the annotated genes. Evidence from the chromosome‐scale pseudomolecules suggests that flax has undergone palaeopolyploidization and mesopolyploidization events, followed by rearrangements and deletions or fusion of chromosome arms from an ancient progenitor with a haploid chromosome number of eight.
LBD18 uses a dual mode of a positive feedback loop to regulate ARF expression and transcriptional activity in Arabidopsis
Authors: Pandey Shashank K. , Lee Han Woo , Kim Min‐Jung , Cho Chuloh , Oh Eunkyoo , Kim Jungmook
Published: April 2018

A hierarchy of transcriptional regulators controlling lateral root formation in Arabidopsis thaliana has been identified, including the AUXIN RESPONSE FACTOR 7 (ARF7)/ARF19‐LATERAL ORGAN BOUNDARIES DOMAIN 16 (LBD16)/LBD18 transcriptional network; however, their feedback regulation mechanisms are not known. Here we show that LBD18 controls ARF activity using the dual mode of a positive feedback loop. We showed that ARF7 and ARF19 directly bind AuxRE in the LBD18 promoter. A variety of molecular and biochemical experiments demonstrated that LBD18 binds a specific DNA motif in the ARF19 promoter to regulate its expression in vivo as well as in vitro. LBD18 interacts with ARFs including ARF7 and ARF19 via the Phox and Bem1 domain of ARF to enhance the transcriptional activity of ARF7 on AuxRE, and competes with auxin/indole‐3‐acetic acid (IAA) repressors for ARF binding, overriding the negative feedback loop exerted by Aux/IAA repressors. Taken together, these results show that LBD18 and ARFs form a double positive feedback loop, and that LBD18 uses the dual mode of a positive feedback loop by binding directly to the ARF19 promoter and through the protein–protein interactions with ARF7 and ARF19. This novel mechanism of feedback loops may constitute a robust feedback mechanism that ensures continued lateral root growth in response to auxin in Arabidopsis.
Multiobjective PID controller design for active suspension system: scalarization approach
Authors: Altinoz O. Tolga
Published: April 2018

In this study, the PID tuning method (controller design scheme) is proposed for a linear quarter model of active suspension system installed on the vehicles. The PID tuning scheme is considered as a multiobjective problem which is solved by converting this multiobjective problem into single objective problem with the aid of scalarization approaches. In the study, three different scalarization approaches are used and compared to each other. These approaches are called linear scalarization (weighted sum), epsilon-constraint and Benson’s methods. The objectives of multiobjective optimization are selected from the time-domain properties of the transient response of the system which are overshoot, rise time, peak time and error (in total there are four objectives). The aim of each objective is to minimize the corresponding property of the time response of the system. First, these four objective is applied to the scalarization functions and then single objective problem is obtained. Finally, these single objective problems are solved with the aid of heuristic optimization algorithms. For this purpose, four optimization algorithms are selected, which are called Particle Swarm Optimization, Differential Evolution, Firefly, and Cultural Algorithms. In total,twelve implementations are evaluated with the same number of iterations. In this study, the aim is to compare the scalarization approaches and optimization algorithm on active suspension control problem. The performance of the corresponding cases (implementations) are numerically and graphically demonstrated on transient responses of the system.
Dynamic scheduling with cancellations: an application to chemotherapy appointment booking
Authors: Göçgün Yasin
Published: April 2018

We study a dynamic scheduling problem that has the feature of due dates and time windows. This problem arises in chemotherapy scheduling where patients from different types have specific target dates along with time windows for appointment. We consider cancellation of appointments. The problem is modeled as a Markov Decision Process (MDP) and approximately solved using a direct-search based approximate dynamic programming (ADP) tehnique. We compare the performance of the ADP technique against the myopic policy under diverse scenarios. Our computational results reveal that the ADP technique outperforms the myopic policy on majority of problem sets we generated.
A conformable calculus of radial basis functions and its applications
Authors: Usta Fuat
Published: April 2018

In this paper we introduced the conformable derivatives and integrals of radial basis functions (RBF) to solve conformable fractional differential equations via RBF collocation method. For that, firstly, we found the conformable derivatives and integrals of power, Gaussian and multiquadric basis functions utilizing the rule of conformable fractional calculus. Then by using these derivatives and integrals we provide a numerical scheme to solve conformable fractional differential equations. Finally we presents some numerical results to confirmed our method
Comparing phase-sensitive and phase-insensitive echolocation target images using a monaural audible sonar
Authors: Kuc Roman
Published: April 2018

This paper describes phase-sensitive and phase-insensitive processing of monaural echolocation waveforms to generate target maps. Composite waveforms containing both the emission and echoes are processed to estimate the target impulse response using an audible sonar. Phase-sensitive processing yields the composite signal envelope, while phase-insensitive processing that starts with the composite waveform power spectrum yields the envelope of the autocorrelation function. Analysis and experimental verification show that multiple echoes form an autocorrelation function that produces near-range phantom-reflector artifacts. These artifacts interfere with true target echoes when the first true echo occurs at a time that is less than the total duration of the target echoes. Initial comparison of phase-sensitive and phase-insensitive maps indicates that both display important target features, indicating that phase is not vital. A closer comparison illustrates the improved resolution of phase-sensitive processing, the near-range phantom-reflectors produced by phase-insensitive processing, and echo interference and multiple reflection artifacts that were independent of the processing.
Nano livers: A sobering discovery
Authors: Nance Elizabeth A.
Published: April 2018

Hepatocyte-mimicking nanocapsules carrying key liver enzymes reduce blood alcohol concentration in intoxicated mice.
Direct Activation of Adenosine Monophosphate-Activated Protein Kinase (AMPK) by PF-06409577 Inhibits Flavivirus Infection through Modification of Host Cell Lipid Metabolism
Authors: Jiménez de Oya Nereida , Blázquez Ana-Belén , Casas Josefina , Saiz Juan-Carlos , Martín-Acebes Miguel A.
Published: April 2018

Mosquito-borne flaviviruses are a group of RNA viruses that constitute global threats for human and animal health. Replication of these pathogens is strictly dependent on cellular lipid metabolism. We have evaluated the effect of the pharmacological activation of AMP-activated protein kinase (AMPK), a master regulator of lipid metabolism, on the infection of three medically relevant flaviviruses, namely, West Nile virus (WNV), Zika virus (ZIKV), and dengue virus (DENV). WNV is responsible for recurrent outbreaks of meningitis and encephalitis, affecting humans and horses worldwide. ZIKV has caused a recent pandemic associated with birth defects (microcephaly), reproductive disorders, and severe neurological complications (Guillain-Barré syndrome). DENV is the etiological agent of the most prevalent mosquito-borne viral disease, which can induce a potentially lethal complication called severe dengue. Our results showed, for the first time, that activation of AMPK using the specific small molecule activator PF-06409577 reduced WNV, ZIKV, and DENV infection. This antiviral effect was associated with an impairment of viral replication due to the modulation of host cell lipid metabolism exerted by the compound. These results support that the pharmacological activation of AMPK, which currently constitutes an important pharmacological target for human diseases, could also provide a feasible approach for broad-spectrum host-directed antiviral discovery.
Activities of Combinations of Antistaphylococcal Antibiotics with Fusidic Acid against Staphylococcal Biofilms in
In Vitro
Static and Dynamic Models
Authors: Siala Wafi , Rodriguez-Villalobos Hector , Fernandes Prabhavathi , Tulkens Paul M. , Van Bambeke Françoise
Published: April 2018

Staphylococcal biofilms are a major cause of therapeutic failure, especially when caused by multiresistant strains. Oral fusidic acid is currently being redeveloped in the United States for skin, skin structure, and orthopedic infections, in which biofilms play a major role. The aim of this study was to examine the activity of fusidic acid alone or combined with other antistaphylococcal drugs against biofilms made by a reference strain and five clinical isolates of
Staphylococcus aureus
or
Staphylococcus epidermidis
in
in vitro
static and dynamic models (microtiter plates and a CDC reactor) exposed to clinically relevant concentrations. In microtiter plates, antibiotics alone were poorly active, with marked differences among strains. At concentrations mimicking the free-drug human maximum concentration of drug in serum (
C
max
), the combination of fusidic acid with linezolid, daptomycin, or vancomycin resulted in increased activity against 4 to 5 strains, while the combination with doxycycline, rifampin, or moxifloxacin increased activity against 1 to 3 strains only. In the CDC reactor, biofilms were grown under constant flow and antibiotic concentrations decreased over time according to human elimination rates. A bactericidal effect was obtained when fusidic acid was combined with daptomycin or linezolid, but not with vancomycin. The higher tolerance of biofilms to antibiotics in the CDC reactor is probably attributable to the more complex architecture they adopt when growing under constant flow. Because biofilms grown in the CDC reactor are considered more similar to those developing
in vivo
, the data support further testing of combinations of fusidic acid with daptomycin or linezolid in models pertinent to chronic skin, skin structure, or orthopedic infections.
Controlled cohort evaluation of theLiveLightermass media campaign’s impact on adults’ reported consumption of sugar-sweetened beverages
Authors: Morley Belinda C , Niven Philippa H , Dixon Helen G , Swanson Maurice G , McAleese Alison B , Wakefield Melanie A
Published: April 2018

Objective

To evaluate theLiveLighter‘Sugary Drinks’ campaign impact on awareness, knowledge and sugar-sweetened beverage (SSB) consumption.

Design

Cohort study with population surveys undertaken in intervention and comparison states at baseline (n=900 each), with 78% retention at follow-up (intervention: n=673; comparison: n=730). Analyses tested interactions by state (intervention, comparison) and time (baseline, follow-up).

Setting and participants

Adults aged 25–49 years residing in the Australian states of Victoria and South Australia.

Intervention

The 6-week mass media campaign ran in Victoria in October/November 2015. It focused on the contribution of SSBs to the development of visceral ‘toxic fat’, graphically depicted around vital organs, and ultimately serious disease. Paid television advertising was complemented by radio, cinema, online and social media advertising, and stakeholder and community engagement.

Primary outcome measure

Self-reported consumption of SSBs, artificially sweetened drinks and water.

Secondary outcome measures

Campaign recall and recognition; knowledge of the health effects of overweight and SSB consumption; perceived impact of SSB consumption on body weight and of reduced consumption on health.

Results

A significant reduction in frequent SSB consumption was observed in the intervention state (intervention: 31% compared with 22%, comparison: 30% compared with 29%; interaction p<0.01). This was accompanied by evidence of increased water consumption (intervention: 66% compared with 73%; comparison: 68% compared with 67%; interaction p=0.09) among overweight/obese SSB consumers. This group also showed increased knowledge of the health effects of SSB consumption (intervention: 60% compared with 71%, comparison: 63% compared with 59%; interaction p<0.05) and some evidence of increased prevalence of self-referent thoughts about SSB’s relationship to weight gain (intervention: 39% compared with 45%, comparison: 43% compared with 38%; interaction p=0.06).

Conclusions

The findings provide evidence of reduced SSB consumption among adults in the target age range following theLiveLightercampaign. This is notable in a context where public health campaigns occur against a backdrop of heavy commercial product advertising promoting increased SSB consumption.
Influence of playing rugby on long-term brain health following retirement: a systematic review and narrative synthesis
Authors: Cunningham Joice , Broglio Steven , Wilson Fiona
Published: April 2018

Objectives

The aim of this review was to systematically investigate long-term brain health in retired rugby players.

Methods

Six databases were systematically searched from inception to January 2018 using Medical Subject Headings and keywords. Two reviewers independently screened studies for inclusion. Cross-sectional studies of living retired male or female rugby players in which at least one cognitive test was used as an outcome measure were included. Data extraction was performed using Strengthening the Reporting of Observational Studies in Epidemiology guidelines. Methodological quality was assessed independently by two reviewers using the Downs and Black methodological quality tool.

Results

This review yielded six studies with an overall methodological quality of ‘moderate’. A total of 672 male retired rugby players (mean ages of 38–52 years) were included in this review. Three studies investigated neuropsychological functioning in retired rugby players in comparison with controls, with no significant evidence of decreased performance in the majority of tests when compared with controls. Five out of the six studies explored self-reported measures of cognition. Three studies compared retired rugby players to controls, one of which found significantly increased subjective cognitive complaints among retired rugby players. The other two studies found that persistent postconcussion symptoms were associated with a higher number of self-reported concussions. Two studies reported decreased fine motor control in retired rugby players in comparison with controls. Neurometabolites and electrophysiological changes were explored by two studies, with minimal and non-significant findings.

Conclusions

Overall findings are mixed. Methodological biases reduce the overall study quality and limited the conclusions that can be drawn. Findings of decreased fine motor control in retired athletes may be influenced by lack of controlling for evidence of upper limb musculoskeletal injuries. While some studies show evidence of reduced cognitive function among former athletes, the results are not significantly lower than population norms. Cognitive findings from this review are inconsistent within and across study cohorts and are biased towards positive findings when self-report methods were selected. Current evidence suggests that large gaps remain in the understanding of the cause-and-effect relationships between playing rugby and long-term brain health in retired players.
Low scale composite Higgs model and 1.8 ∼2 TeV diboson excess
Authors: Bian Ligong , Liu Da , Shu Jing
Published: April 2018

We consider a simple solution to explain the recent diboson excess observed by ATLAS and CMS Collaborations in models with custodial symmetry [Formula: see text]. The [Formula: see text] triplet vector boson [Formula: see text] with mass range of [Formula: see text] TeV would be produced through the Drell–Yan process with sizable diboson decay branching to account for the excess. The other [Formula: see text] bidoublet axial vector boson [Formula: see text] would cancel all deviations of electroweak obervables induced by [Formula: see text] even if the SM fermions mix with some heavy vector-like (composite) fermions which couple to [Formula: see text] (“nonuniversally partially composite”), therefore allows arbitrary couplings between each SM fermion and [Formula: see text]. We present our model in the “General Composite Higgs” framework with [Formula: see text] breaking at scale [Formula: see text] and demand the first Weinberg sum rule and positive gauge boson form factors as the theoretical constraints. We find that our model can fit the diboson excess very well if the left-handed SM light quarks, charged leptons and tops have zero, zero/moderately small and moderate/large composite components for reasonable values of [Formula: see text] and [Formula: see text]. The correlation between tree level [Formula: see text] parameter and the [Formula: see text] suggest a large [Formula: see text] contribution to [Formula: see text] and it is indeed a [Formula: see text] effect in our parameter space which provides a strong hint for our scenario if this diboson excess is confirmed by the [Formula: see text] TeV LHC Run II.
Top partner-resonance interplay in a composite Higgs framework
Authors: Yepes Juan , Zerwekh Alfonso
Published: April 2018

Guided us by the scenario of weak scale naturalness and the possible existence of exotic resonances, we have explored in a [Formula: see text] Composite Higgs setup the interplay among three matter sectors: elementary, top partners and vector resonances. We parametrize it through explicit interactions of spin-1 [Formula: see text]-resonances, coupled to the [Formula: see text]-invariant fermionic currents and tensors presented in this work. Such invariants are built upon the Standard Model fermion sector as well as top partners sourced by the unbroken [Formula: see text]. The mass scales entailed by the top partner and vector resonance sectors will control the low energy effects emerging from our interplaying model. Its phenomenological impact and parameter spaces have been considered via flavor-dijet processes and electric dipole moments bounds. Finally, the strength of the Nambu–Goldstone symmetry breaking and the extra couplings implied by the top partner mass scales are measured in accordance with expected estimations.
Role of switching-on and -off effects in the vacuum instability
Authors: Adorno T. C. , Ferreira R. , Gavrilov S. P. , Gitman D. M.
Published: April 2018

We find exact differential mean numbers of fermions and bosons created from the vacuum due to a composite electric field of special configuration. This configuration imitates a finite switching-on and -off regime and consists of fields that switch on exponentially from the infinitely remote past, remains constant during a certain interval [Formula: see text] and switch off exponentially to the infinitely remote future. We show that calculations in the slowly varying field approximation are completely predictable in the framework of a locally constant field approximation. Beyond the slowly varying field approximation, we study effects of fast switching on and off in a number of cases when the size of the dimensionless parameter [Formula: see text] is either close or exceeds the threshold value that determines the transition from a regime sensitive to on–off parameters to the slowly varying regime for which these effects are secondary.
Beam dynamics pre-design with KONUS principle for the DTL of SPPC p-Linac
Authors: Liu Jing , Li Haipeng , Lu Yuanrong , Su Jiancang , Liu Xiaolong , Fu Qi
Published: April 2018

As the Higgs bosons were observed on the LHC in 2012, a two-stage particle collider program named CEPC-SPPC is proposed for precise measurement of Higgs properties and exploring the new physics models. In order to deliver a 2.1-TeV proton beam into the Super Proton–Proton Collider (SPPC), the injector chain will use a 1.2-GeV proton linac (p-Linac) and three synchrotrons of p-RCS, MSS and SS. This paper focuses on the preliminary conceptual design of the DTL within the p-Linac and mainly concerns about the beam dynamics studies. Taking advantages of the KONUS principle and LORASR code, a 325 MHz, 50.65 MeV DTL design which is composed of three tanks in 15.6 m will be presented. The whole DTL contains 129 gaps for beam acceleration, one quadruple doublet which is behind the buncher and eight quadruple triplets of which three are located after each tank, respectively. The aims of this pre-study are to optimize the acceleration electric field distribution together with the focusing magnetic field parameters, enhance the beam transmission quality of beam envelopes, particle distribution and energy spread, then improve the DTL performance in terms of transmission efficiency and so on. The results of the analyses show that the DTL pre-design achieves 16.8 times high energy gain and meets all the p-Linac requirements well.
General heat kernel coefficients for massless free spin-3/2 Rarita–Schwinger field
Authors: Karan Sudip , Kumar Shashank , Panda Binata
Published: April 2018

We review the general heat kernel method for the Dirac spinor field as an elementary example in any arbitrary background. We, then compute the first three Seeley–DeWitt coefficients for the massless free spin-3/2 Rarita–Schwinger field without imposing any limitations on the background geometry.
Magnetic charge and photon mass: Physical string singularities, Dirac condition, and magnetic confinement
Authors: Evans Timothy J. , Singleton Douglas
Published: April 2018

We find exact, simple solutions to the Proca version of Maxwell’s equations with magnetic sources. Several properties of these solutions differ from the usual case of magnetic charge with a massless photon: (i) the string singularities of the usual 3-vector potentials become real singularities in the magnetic fields; (ii) the different 3-vector potentials become gauge inequivalent and physically distinct solutions; (iii) the magnetic field depends on r and [Formula: see text] and thus is no longer rotationally symmetric; (iv) a combined system of electric and magnetic charge carries a field angular momentum even when the electric and magnetic charges are located at the same place (i.e. for dyons); (v) for these dyons, one recovers the standard Dirac condition despite the photon being massive. We discuss the reason for this. We conclude by proposing that the string singularity in the magnetic field of an isolated magnetic charge suggests a confinement mechanism for magnetic charge, similar to the flux tube confinement of quarks in QCD.
Low-Power Modified Shift-Add Multiplier Design Using Parallel Prefix Adder
Authors: Pinto Rohan , Shama Kumara
Published: April 2018

Multipliers are the building blocks of every digital signal processor (DSP). The performance of any digital system is dependent on the adder design and to a large extent on the multiplier block. Area and power dissipation are the major considerations in a multiplier design due to its complexity. In this paper, an efficient multiplier “bypass zero feed multiplicand directly,” based on shift-add multiplication, has been proposed for low-power application. As the shift-add multiplication is a repetitive process of addition, the implementation time of an adder is reduced by using the proposed parallel prefix adders designed based on revised Ling equations. The proposed 8-bit, 16-bit and 32-bit multipliers are implemented using 180-nm and 90-nm CMOS technologies. Simulation results reveal that the proposed multiplier is fast and lowers the power by 35% predominantly for a 32-bit multiplier.
Improving ILP via Fused In-Order Superscalar and VLIW Instruction Dispatch Methods
Authors: Hou Yumin , Wang Xu , Fu Jiawei , Ma Junping , He Hu , Yang Xu
Published: April 2018

In order to expand the computation capability of digital signal processing on a General Purpose Processor (GPP), we propose a fused microarchitecture that improves Instruction Level Parallelism (ILP) by supporting both in-order superscalar and very long instruction word (VLIW) dispatch methods in a single pipeline. This design is based on ARMv7-A&R Instruction Set Architecture (ISA). To provide a performance comparison, we first design an in-order superscalar processor, considering that ARM GPPs always adopt superscalar approaches. And then we expand VLIW dispatch method based on this processor, to realize the fused microarchitecture. The two designs are both evaluated on the Xilinx 7-series FPGA (XC7K325T-2FFG900C), using Xilinx Vivado design suite. The results show that, compared with the superscalar processor, the processor working under VLIW mode can improve the performance by 15% and 8%, respectively, when running EEMBC and DSPstone benchmarks. We also run the two benchmarks on ARM Cortex-A9 processor, which is integrated in the Zynq-7000 AP SoC device on Xilinx ZC706 evaluation board. The processor in VLIW mode shows 44% and 30% performance improvements than ARM Cortex-A9. The fused microarchitecture adopts a combined bimodal and PAp branch prediction method. This method achieves 93.7% prediction accuracy with limited hardware overhead.
A Low-Power High-Linear Time-to-Digital Converter for Measuring R-R Intervals in ECG Signal Optimized by Neural Network and TLBO Algorithm
Authors: Ghanavati B. , Abiri E. , Salehi M. R. , Azhdari N.
Published: April 2018

In this paper, a two-stage time interpolation time-to-digital converter (TDC) is proposed to achieve adequate resolution and wide dynamic range for measuring R-R intervals in QRS detection. The architecture is based on a coarse counter and a couple of two-stage interpolator circuit in order to improve the conversion linearity. The proposed TDC is modeled with the neural network, while the teacher–learner-based optimization algorithm (TLBO) is used to optimize the integral nonlinearity (INL) of the proposed TDC. The proposed optimization method shows a characteristic close to the ideal output of the TDC behavior over a wide input range. Using the achieved results of the TLBO algorithm simulation results using CADENCE VIRTUOSO and standard 180[Formula: see text]nm CMOS technology shows 1.2[Formula: see text]s dynamic range, 100[Formula: see text]ns resolution, 0.19[Formula: see text]mW power consumption and area of 0.16[Formula: see text]mm2. The proposed circuit can find application in biomedical engineering systems and other fields where long and accurate time interval measurement is needed.
Nonlinear Analysis of Hysteretic Modulation-Based Sliding Mode Controlled Quadratic Buck–Boost Converter
Authors: Kavitha Muppala Kumar , Kavitha Anbukumar
Published: April 2018

In this paper, the dynamics of hysteresis current-controlled quadratic buck-boost converter is investigated in detail. The system model is derived based on the sliding mode approach and also in its dimensionless form for algebraic brevity. The stability of the system is disclosed with the aid of the movement of eigenvalues. Onset of Hopf bifurcation is identified when the complex conjugate eigenvalue pair crosses the imaginary axis of the complex plane. The stability boundary is drawn to benefit the power electronics engineer for a stable and reliable design. The computer simulation of the switched model is performed using MATLAB/Simulink software to uncover the sequential occurrence of nonlinear behavior exhibited due to Hopf bifurcation for variation in control parameters and the input voltage. The phase portrait disclosing the subtle periodicity is plotted at different operating points to elicit that the stable period-1 attractor bifurcates to the quasi-periodic orbit and finally to a limit cycle. The precise dynamic of the phase portrait is also captured using the Poincare section. Experimental outputs are presented for confirming the low-frequency bifurcation scenario witnessed in the simulated and analytical results.
Tunable CMOS Active Inductor Using Widlar Current Source
Authors: Patel Dhara P , Oza-Rahurkar Shruti
Published: April 2018

A novel tuning principle for simple gyrator-based CMOS active inductor (AI) circuit is presented. The method makes use of Widlar current source to enhance the quality factor. The simulation of the proposed AI provides a maximum quality factor of 1819 at 2.88[Formula: see text]GHz. The AI shows the inductive bandwidth of 1.66[Formula: see text]GHz to 3.16[Formula: see text]GHz and power consumption of 6.87[Formula: see text]mW. The other characterization factors such as linearity, supply voltage sensitivity and noise analysis are discussed. The performance of the tunable AI using Widlar current source are compared with the same using a simple current mirror. An AI using a conventional current mirror (CCM) and Widlar current source have been implemented in the 0.18[Formula: see text][Formula: see text]m CMOS technology.
Positive and Negative Feedback for Linearity Improvement and PVT Compensation of the Ramp Generator
Authors: Padash Mohsen , Yargholi Mostafa
Published: April 2018

Linearity of ramp signals is one of the most important aspects for many applications such as single-slope analog to digital converters (ADCs); another important aspect is the total power dissipation. Applications like high-resolution single-slope ADCs that can be used in portable devices demanded accurate ramp generator with low power dissipation. This paper presents a low power ramp generator with linearity improvement that achieved by a positive feedback circuit and negative feedback for compensation of the variations in process, voltage and temperature. Derived equations of the proposed ramp generator circuit show that linearity of the output ramp, with proper choosing of device sizes, can be enhanced significantly. Also, for proving of linearity enhancement, the circuit design and post-layout simulations were done in TSMC 0.18[Formula: see text][Formula: see text]m and 90[Formula: see text]nm CMOS technologies. Simulation results show that linearity of the circuit improved by a factor of 8 and total ramp resolution improved about 3 bit, whereas power dissipation of the circuit is about 8[Formula: see text][Formula: see text]W and entire layout core area is near 800[Formula: see text][Formula: see text]m2.
THE POTENTIAL APPROACH IN PRACTICE
Authors: KLUGE T. , ROGERS L. C. G.
Published: April 2018

This paper studies the fitting of Markov chain potential models to interest-rate derivative prices in four currencies simultaneously, using sequential Monte Carlo methodology (particle filtering). The potential approach starts from some Markov process which is supposed to drive the random observations, and there have been many studies where this Markov process is taken to be a diffusion; fewer studies have worked from a finite-state Markov chain, and this seems to be the first study to attempt to fit such models to data. With the available data, we show impressive agreement of the fitted models with market prices.
Online minimum error entropy algorithm with unbounded sampling
Authors: Wang Cheng , Hu Ting
Published: April 2018

Minimum error entropy (MEE) criterion is an important optimization method in information theoretic learning (ITL) and has been widely used and studied in various practical scenarios. In this paper, we shall introduce the online MEE algorithm for dealing with big datasets, associated with reproducing kernel Hilbert spaces (RKHS) and unbounded sampling processes. Explicit convergence rate will be given under the conditions of regularity of the regression function and polynomially decaying step sizes. Besides its low complexity, we will also show that the learning ability of online MEE is superior to the previous work in the literature. Our main techniques depend on integral operators on RKHS and probability inequalities for random variables with values in a Hilbert space.
Quantum correlations in critical XXZ system and LMG model
Authors: Ye Biao-Liang , Li Bo , Li-Jost Xianqing , Fei Shao-Ming
Published: April 2018

We investigate the quantum phase transitions for the [Formula: see text] spin-1/2 chains via the quantum correlations between the nearest and next-to-nearest neighbor spins characterized by negativity, information deficit, trace distance discord and local quantum uncertainty. It is shown that all these correlations exhibit the quantum phase transitions at [Formula: see text]. However, only information deficit and local quantum uncertainty can demonstrate quantum phase transitions at [Formula: see text]. The analytical and numerical behaviors of the quantum correlations for the [Formula: see text] system are presented. We also consider quantum correlations in the Hartree–Fock ground state of the Lipkin–Meshkov–Glick (LMG) model.
A Stabilization Method of F-barES-FEM-T4 for Dynamic Explicit Analysis of Nearly Incompressible Materials
Authors: Iida Ryoya , Onishi Yuki , Amaya Kenji
Published: April 2018

A stabilization method of the F-bar aided edge-based smoothed finite element method with four-node tetrahedral elements (F-barES-FEM-T4), which is named SymF-barES-FEM-T4, is proposed. The proposed formulation aims to remove the instability associated with energy divergence of F-barES-FEM-T4 in dynamic analysis. The stiffness matrix of F-barES-FEM-T4 is asymmetric due to the adoption of F-bar method, meanwhile that of SymF-barES-FEM-T4 is symmetrized so that the dynamics system of the formulation is stabilized. The differences between F-barES-FEM-T4 and SymF-barES-FEM-T4 in their formulations are only the definition of the [Formula: see text]-matrix and the corresponding volume in the internal force calculation. Therefore, SymF-barES-FEM-T4 is applicable in dynamic explicit schemes as is the case with F-barES-FEM-T4. A few demonstrations of dynamic explicit analysis for nearly incompressible materials reveal that SymF-barES-FEM-T4 conserves the total energy and does not cause energy divergence in the free vibration problems. They also reveal that SymF-barES-FEM-T4 has a moderate capability in the suppression of pressure checkerboarding: worse than F-barES-FEM-T4 but better than Selective ES/NS-FEM-T4.