bluuebunny/crossref_metadata_2025 huggingface dataset:
Seasonal pasture myopathy/atypical myopathy in North America associated with ingestion of hypoglycin A within seeds of the box elder tree
Authors: Valberg S. J. , Sponseller B. T. , Hegeman A. D. , Earing J. , Bender J. B. , Martinson K. L. , Patterson S. E. , Sweetman L.
Published: September 2012

Reasons for performing study

We hypothesised that seasonal pasture myopathy (SPM), which closely resembles atypical myopathy (AM), was caused by ingestion of a seed‐bearing plant abundant in autumn pastures.

Objectives

To identify a common seed‐bearing plant among autumn pastures of horses with SPM, and to determine whether the toxic amino acid hypoglycin A was present in the seeds and whether hypoglycin metabolites were present in SPM horse serum or urine.

Methods

Twelve SPM cases, 11 SPM pastures and 23 control farms were visited to identify a plant common to all SPM farms in autumn. A common seed was analysed for amino acid composition (n = 7/7) by GC‐MS and its toxic metabolite (n = 4/4) identified in conjugated form in serum [tandem mass spectrometry (MS/MS)] and urine [gas chromatography (GC) MS]. Serum acylcarnitines and urine organic acid profiles (n = 7) were determined for SPM horses.

Results

Seeds from box elder trees (Acer negundo) were present on all SPM and 61% of control pastures. Hypoglycin A, known to cause acquired multiple acyl‐CoA dehydrogenase deficiency (MADD), was found in box elder seeds. Serum acylcarnitines and urine organic acid profiles in SPM horses were typical for MADD. The hypoglycin A metabolite methylenecyclopropylacetic acid (MCPA), known to be toxic in other species, was found in conjugated form in SPM horse serum and urine. Horses with SPM had longer turn‐out, more overgrazed pastures, and less supplemental feeding than control horses.

Potential relevance

For the first time, SPM has been linked to a toxin in seeds abundant on autumn pastures whose identified metabolite, MCPA, is known to cause acquired MADD, the pathological mechanism behind SPM and AM. Further research is required to determine the lethal dose of hypoglycin A in horses, as well as factors that affect annual seed burden and hypoglycin A content in Acer species in North America and Europe.
More than a mirage: A large‐scale assessment centre with more dimension variance than exercise variance
Authors: Guenole Nigel , Chernyshenko Oleksandr S. , Stark Stephen , Cockerill Tony , Drasgow Fritz
Published: September 2012

Assessment centres (ACs) are widely recognized to be among the best tools for assessing and developing management talent (Assessment Centres and Global Talent Management, 2011, Gower: London). Yet, the current consensus about the construct validity of ACs is that exercises rather than dimensions explain the majority of variance in ratings. Because much of the data on which these conclusions are based are now old, it is worthwhile to periodically re‐examine this issue to see whether well‐implemented designs produce better measurements of dimensions. We present results from 1,205 executive‐level leaders from Fortune 500 firms across Europe and North America, who participated in developmental ACs that use modern design principles where assessors were formally examined to ensure they had a common frame or reference. Our results showed that while dimensions and exercises mutually determined ratings, more variation was owing to dimensions.

Practitioner Points

Modern assessment centre designs can yield dimension scores that reflect dimensions more than exercises;

The psychometric characteristics of operational ACs should be regularly monitored as the characteristics of any single AC may differ widely from meta‐analytic averages.
Gingival advanced glycation end‐products in diabetes mellitus‐associated chronic periodontitis: an immunohistochemical study
Authors: Zizzi A. , Tirabassi G. , Aspriello S. D. , Piemontese M. , Rubini C. , Lucarini G.
Published: September 2012

Background and Objective

The accumulation of advanced glycation end‐products (AGEs) seems to play an important role in the development of diabetes mellitus (DM)‐associated periodontitis; however, some aspects of this issue are still scarcely known, such as the expression of AGEs in type 1 DM‐associated periodontitis and the clinical factors able to affect their accumulation. This study aimed to clarify these points by evaluating the expression of AGEs in DM‐associated periodontitis.

Material and Methods

Sixteen systemically and periodontally healthy subjects and 48 subjects suffering from generalized, severe, chronic periodontitis (16 with type 1 DM, 16 with type 2 DM and 16 systemically healthy subjects) were studied clinically, periodontally and metabolically. The immunohistochemical expression of AGEs in gingival tissues was also evaluated.

Results

Subjects affected with type 1 DM presented a significantly higher percentage of AGE‐positive cells than did subjects affected with type 2 DM, not only in the epithelium, but also in vessels and fibroblasts. A positive and significant correlation was found between gingival expression of AGEs and length of time affected with DM both in type 1 and type 2 DM; glycated hemoglobin, lipid profile, body mass index and age did not correlate significantly with gingival AGEs in any of the classes of subjects studied.

Conclusions

Gingival AGEs are increased in both type 1 and type 2 DM‐associated periodontitis; however, the clinical parameter that determines their accumulation, and therefore their degree of influence on the development of DM‐associated periodontitis, may be the duration of DM.
Natural competence in Vibrio cholerae is controlled by a nucleoside scavenging response that requires CytR‐dependent anti‐activation
Authors: Antonova Elena S. , Bernardy Eryn E. , Hammer Brian K.
Published: September 2012

Competence for genetic transformation in Vibrio cholerae is triggered by chitin‐induced transcription factor TfoX and quorum sensing (QS) regulator HapR. Transformation requires expression of ComEA, described as a DNA receptor in other competent bacteria. A screen for mutants that poorly expressed a comEA–luciferase fusion identified cytR, encoding the nucleoside scavenging cytidine repressor, previously shown in V. cholerae to be a biofilm repressor and positively regulated by TfoX, but not linked to transformation. A ΔcytR mutant was non‐transformable and defective in expression of comEA and additional TfoX‐induced genes, including pilA (transformation pseudopilus) and chiA‐1 (chitinase). In Escherichia coli, ‘anti‐activation’ of nucleoside metabolism genes, via protein–protein interactions between critical residues in CytR and CRP (cAMP receptor protein), is disrupted by exogenous cytidine. Amino acid substitutions of the corresponding V. cholerae CytR residues impaired expression of comEA, pilA and chiA‐1, and halted DNA uptake; while exogenous cytidine hampered comEA expression levels and prevented transformation. Our results support a speculative model that when V. cholerae reaches high density on chitin, CytR–CRP interactions ‘anti‐activate’ multiple genes, including a possible factor that negatively controls DNA uptake. Thus, a nucleoside scavenging mechanism couples nutrient stress and cell–cell signalling to natural transformation in V. cholerae as described in other bacterial pathogens.
The novel HLA‐A*03:143 allele, identified by sequence‐based typing in an Italian family
Authors: Testi M. , Stellitano C. , Di Luzio A. , Battarra M. , Andreani M.
Published: September 2012

HLA‐A*03:143 has one nucleotide change from A*03:01: 01:01 at nt 406 from G to C, resulting in an amino acid change at codon 112 of exon 3 from Gly to Arg.
BAT1, a putative acyltransferase, modulates brassinosteroid levels in Arabidopsis
Authors: Choi Sunhwa , Cho Young‐hyun , Kim Kangmin , Matsui Minami , Son Seung‐Hyun , Kim Seong‐Ki , Fujioka Shozo , Hwang Ildoo
Published: September 2012

Brassinosteroids (BRs) are essential for various aspects of plant development. Cellular BR homeostasis is critical for proper growth and development of plants; however, its regulatory mechanism remains largely unknown. BAT1 (BR‐related acyltransferase 1), a gene encoding a putative acyltransferase, was found to be involved in vascular bundle development in a full‐length cDNA over‐expressor (FOX) screen. Over‐expression of BAT1 resulted in typical BR‐deficient phenotypes, which were rescued by exogenously applied castasterone and brassinolide. Analyses of BR profiles demonstrated that BAT1 alters levels of several brassinolide biosynthetic intermediates, including 6‐deoxotyphasterol, typhasterol and 6‐deoxocastasterone. BAT1 is mainly localized in the endoplasmic reticulum. BAT1 is highly expressed in young tissues and vascular bundles, and its expression is induced by auxin. These data suggest that BAT1 is involved in BR homeostasis, probably by conversion of brassinolide intermediates into acylated BR conjugates.
ZmGA3ox2, a candidate gene for a major QTL,qPH3.1, for plant height in maize
Authors: Teng Feng , Zhai Lihong , Liu Ruixiang , Bai Wei , Wang Liqiu , Huo Dongao , Tao Yongsheng , Zheng Yonglian , Zhang Zuxin
Published: September 2012

Maize plant height is closely associated with biomass, lodging resistance and grain yield. Determining the genetic basis of plant height by characterizing and cloning plant height genes will guide the genetic improvement of crops. In this study, a quantitative trait locus (QTL) for plant height, qPH3.1, was identified on chromosome 3 using populations derived from a cross between Zong3 and its chromosome segment substitution line, SL15. The plant height of the two lines was obviously different, and application of exogenous gibberellin A3 removed this difference. QTL mapping placed qPH3.1 within a 4.0 cM interval, explaining 32.3% of the phenotypic variance. Furthermore, eight homozygous segmental isolines (SILs) developed from two larger F2 populations further narrowed down qPH3.1 to within a 12.6 kb interval. ZmGA3ox2, an ortholog of OsGA3ox2, which encodes a GA3 β‐hydroxylase, was positionally cloned. Association mapping identified two polymorphisms in ZmGA3ox2 that were significantly associated with plant height across two experiments. Quantitative RT‐PCR showed that SL15 had higher ZmGA3ox2 expression relative to Zong3. The resultant higher GA1 accumulation led to longer internodes in SL15 because of increased cell lengths. Moreover, a large deletion in the coding region of ZmGA3ox2 is responsible for the dwarf mutant d1‐6016. The successfully isolated qPH3.1 enriches our knowledge on the genetic basis of plant height in maize, and provides an opportunity for improvement of plant architecture in maize breeding.
Mechanistic Study of Subatmospheric Pressure, Subcooled, Flow Boiling of Water on Structured-Porous Surfaces
Authors: Penley S. J. , Wirtz R. A.
Published: September 2012

Subcooled flow boiling experiments with water at 0.2-atm pressure assess the utility of fine filament screen laminate enhanced surfaces as high-performance boiling surfaces. Experiments are conducted on vertically oriented, multilayer copper laminates in distilled water. The channel Reynolds number is varied from 2000 to 20,000, and subcooling ranges from 2 to 35 K. Boiling performance is documented for ten different porous surfaces having pore hydraulic diameters ranging from 39 μm to 105 μm, and surface area enhancement ratios ranging from 5 to 37. Heat flux of up to 446 W/cm2 is achieved at 35 K subcooling at a channel Reynolds number of 6000, which represents a 3.5-fold increase in critical heat flux (CHF) over that of the saturated pool boiling on the same surface. Results show that CHF is strongly correlated with subcooling, and the effect of subcooling is more pronounced as the channel Reynolds number is increased. It is found that CHF enhancement due to subcooling and channel Reynolds number is intrinsically linked to the surface area enhancement ratio, which has an optimum that depends on the degree of subcooling. High-speed video imagery (up to 8100 fps) and long-range microscopy are used to document bubble dynamics. Boiling mechanisms inherent to subcooling, enhanced surface geometry, and CHF are discussed.
Status and Solutions for the World’s Unassessed Fisheries
Authors: Costello Christopher , Ovando Daniel , Hilborn Ray , Gaines Steven D. , Deschenes Olivier , Lester Sarah E.
Published: September 2012

First, Find Fish

While salmon, cod, and tuna fisheries are regularly monitored and assessed, this is not the case for about 80% of the fish species harvested throughout the world.

Costello
et al.

(p.
517
published online 27 September; see the Perspective by

Pikitch

) used a model that integrates harvest, population, and ecological data to estimate the status of unassessed fisheries, based on ecologically analogous, regularly assessed fisheries. Generally, unassessed fisheries are in worse condition with declining fish stocks compared with regularly assessed fisheries.
Jet-Launching Structure Resolved Near the Supermassive Black Hole in M87
Authors: Doeleman Sheperd S. , Fish Vincent L. , Schenck David E. , Beaudoin Christopher , Blundell Ray , Bower Geoffrey C. , Broderick Avery E. , Chamberlin Richard , Freund Robert , Friberg Per , Gurwell Mark A. , Ho Paul T. P. , Honma Mareki , Inoue Makoto , Krichbaum Thomas P. , Lamb James , Loeb Abraham , Lonsdale Colin , Marrone Daniel P. , Moran James M. , Oyama Tomoaki , Plambeck Richard , Primiani Rurik A. , Rogers Alan E. E. , Smythe Daniel L. , SooHoo Jason , Strittmatter Peter , Tilanus Remo P. J. , Titus Michael , Weintroub Jonathan , Wright Melvyn , Young Ken H. , Ziurys Lucy M.
Published: September 2012

Black Hole Close-Up

M87 is a giant elliptical galaxy about 55 million light-years away. Accretion of matter onto its central massive black hole is thought to power its relativistic jet. To probe structures on scales similar to that of the black hole's event horizon,

Doeleman
et al.

(p.
355
, published online 27 September) observed the relativistic jet in M87 at a wavelength of 1.3 mm using the Event Horizon Telescope, a special purpose, very-long-baseline interferometry array consisting of four radio telescopes located in Arizona, California, and Hawaii. The analysis suggests that the accretion disk that powers the jet orbits in the same direction as the spin of the black hole.
An Immunosurveillance Mechanism Controls Cancer Cell Ploidy
Authors: Senovilla Laura , Vitale Ilio , Martins Isabelle , Tailler Maximilien , Pailleret Claire , Michaud Mickaël , Galluzzi Lorenzo , Adjemian Sandy , Kepp Oliver , Niso-Santano Mireia , Shen Shensi , Mariño Guillermo , Criollo Alfredo , Boilève Alice , Job Bastien , Ladoire Sylvain , Ghiringhelli François , Sistigu Antonella , Yamazaki Takahiro , Rello-Varona Santiago , Locher Clara , Poirier-Colame Vichnou , Talbot Monique , Valent Alexander , Berardinelli Francesco , Antoccia Antonio , Ciccosanti Fabiola , Fimia Gian Maria , Piacentini Mauro , Fueyo Antonio , Messina Nicole L. , Li Ming , Chan Christopher J. , Sigl Verena , Pourcher Guillaume , Ruckenstuhl Christoph , Carmona-Gutierrez Didac , Lazar Vladimir , Penninger Josef M. , Madeo Frank , López-Otín Carlos , Smyth Mark J. , Zitvogel Laurence , Castedo Maria , Kroemer Guido
Published: September 2012

Keeping Cancer Cells At Bay

Cancer cells are often aneuploid; that is, they have an abnormal number of chromosomes. But to what extent this contributes to the tumorigenic phenotype is not clear.

Senovilla
et al.

(p.
1678
; see the Perspective by

Zanetti and Mahadevan

) found that tetraploidization of cancer cells can cause them to become immunogenic and thus aid in their clearance from the body by the immune system. Cells with excess chromosomes put stress on the endoplasmic reticulum, which leads to movement of the protein calreticulin to the cell surface. Calreticulin exposure in turn caused recognition of cancer cells in mice by the host immune system. Thus, the immune system appears to serve a protective role in eliminating hyperploid cells that must be overcome to allow unrestricted growth of cancer cells.
Sedlin Controls the ER Export of Procollagen by Regulating the Sar1 Cycle
Authors: Venditti Rossella , Scanu Tiziana , Santoro Michele , Di Tullio Giuseppe , Spaar Alexander , Gaibisso Renato , Beznoussenko Galina V. , Mironov Alexander A. , Mironov Alexander , Zelante Leopoldo , Piemontese Maria Rosaria , Notarangelo Angelo , Malhotra Vivek , Vertel Barbara M. , Wilson Cathal , De Matteis Maria Antonietta
Published: September 2012

A Tight Squeeze

During intracellular transport, the export of procollagen from the endoplasmic reticulum is intriguing because procollagen is too large to fit into conventional coat protein complex II (COPII)–coated transport vesicles. Recent work has implicated the receptor TANGO1 in procollagen export. Now,

Venditti
et al.

(p.
1668
) report that TANGO1 recruits Sedlin—also known as TRAPPC2, a homolog of the yeast TRAPP subunit Trs20—and helps to allow COPII-coated carriers to grow large enough to incorporate procollagen.
A Physically Transient Form of Silicon Electronics
Authors: Hwang Suk-Won , Tao Hu , Kim Dae-Hyeong , Cheng Huanyu , Song Jun-Kyul , Rill Elliott , Brenckle Mark A. , Panilaitis Bruce , Won Sang Min , Kim Yun-Soung , Song Young Min , Yu Ki Jun , Ameen Abid , Li Rui , Su Yewang , Yang Miaomiao , Kaplan David L. , Zakin Mitchell R. , Slepian Marvin J. , Huang Yonggang , Omenetto Fiorenzo G. , Rogers John A.
Published: September 2012

Reversible Implants

Silicon electronics are generally designed to be stable and robust—it would be counterproductive if the key parts of your computer or cell phone slowly dissolved away while you were using it. In order to develop transient electronics for use as medical implants,

Hwang
et al.

(p.
1640
, see the cover) produced a complete set of tools and materials that would be needed to make standard devices. Devices were designed to have a specific lifetime, after which the component materials, such as porous silicon and silk, would be resorbed by the body.
Life in a Contaminated World
Authors: Guillette Louis J. , Iguchi Taisen
Published: September 2012

Exposure to pesticides and other chemicals can have complex long-term health effects.
R. Duncan Luce (1925–2012)
Authors: McClelland James L.
Published: September 2012

A pioneer in the social sciences combined mathematics and psychology to understand human behavior.
Ice-Free Arctic Sea May Be Years, Not Decades, Away
Authors: Kerr Richard A.
Published: September 2012

Summer Arctic sea ice will be a goner far sooner than the end of the century, as current models predict. How far wrong the models might be, however, is still very much in dispute.
Turning From War to Peace in Papua New Guinea
Authors: Culotta Elizabeth
Published: September 2012

In this week's issue of
Science
, researchers document an astonishing turn toward peace among the Enga, a clan in Papua New Guinea with a fearsome reputation for violent conflict.
Where Asia's Monsoons Go to Die
Authors: Larson Christina
Published: September 2012

An ambitious effort is gathering tree-ring samples from across Asia as proxies for past climate conditions.
Satellite Labs Extend Science
Authors: Service Robert F.
Published: September 2012

A new type of lab links Western scientists who want to expand with emerging nations seeking access to world-class researchers.
How to Go Global
Authors: Service Robert F.
Published: September 2012

Jordanian chemist Omar Yaghi has launched the Center for Global Mentoring to help faculty members set up satellite labs around the world.
Clinically Relevant Gram-Negative Resistance Mechanisms Have No Effect on the Efficacy of MC-1, a Novel Siderophore-Conjugated Monocarbam
Authors: McPherson Craig J. , Aschenbrenner Lisa M. , Lacey Brian M. , Fahnoe Kelly C. , Lemmon Margaret M. , Finegan Steven M. , Tadakamalla Baswanth , O'Donnell John P. , Mueller John P. , Tomaras Andrew P.
Published: October 2012

The incidence of hospital-acquired infections with multidrug-resistant (MDR) Gram-negative pathogens is increasing at an alarming rate. Equally alarming is the overall lack of efficacious therapeutic options for clinicians, which is due primarily to the acquisition and development of various antibiotic resistance mechanisms that render these drugs ineffective. Among these mechanisms is the reduced permeability of the outer membrane, which prevents many marketed antibiotics from traversing this barrier. To circumvent this, recent drug discovery efforts have focused on conjugating a siderophore moiety to a pharmacologically active compound that has been designed to hijack the bacterial siderophore transport system and trick cells into importing the active drug by recognizing it as a nutritionally beneficial compound. MC-1, a novel siderophore-conjugated β-lactam that promotes its own uptake into bacteria, has exquisite activity against many Gram-negative pathogens. While the inclusion of the siderophore was originally designed to facilitate outer membrane penetration into Gram-negative cells, here we show that this structural moiety also renders other clinically relevant antibiotic resistance mechanisms unable to affect MC-1 efficacy. Resistance frequency determinations and subsequent characterization of first-step resistant mutants identified PiuA, a TonB-dependent outer membrane siderophore receptor, as the primary means of MC-1 entry into
Pseudomonas aeruginosa
. While the MICs of these mutants were increased 32-fold relative to the parental strain
in vitro
, we show that this resistance phenotype is not relevant
in vivo
, as alternative siderophore-mediated uptake mechanisms compensated for the loss of PiuA under iron-limiting conditions.
Pertussis Toxin Exacerbates and Prolongs Airway Inflammatory Responses during Bordetella pertussis Infection
Authors: Connelly Carey E. , Sun Yezhou , Carbonetti Nicholas H.
Published: October 2012

Throughout infection, pathogenic bacteria induce dramatic changes in host transcriptional repertoires. An understanding of how bacterial factors influence host reprogramming will provide insight into disease pathogenesis. In the human respiratory pathogenBordetella pertussis, the causative agent of whooping cough, pertussis toxin (PT) is a key virulence factor that promotes colonization, suppresses innate immune responses during early infection, and causes systemic disease symptoms. To determine the full extent of PT-associated gene regulation in the airways through the peak of infection, we measured global transcriptional profiles in the lungs of BALB/c mice infected with wild-type (WT) or PT-deficient (ΔPT)B. pertussis. ΔPT bacteria were inoculated at a dose equivalent to the WT dose and at a high dose (ΔPThigh) to distinguish effects caused by higher bacterial loads achieved in WT infection from effects associated with PT. The results demonstrated that PT was associated with a significant upregulation of immune and inflammatory response genes as well as several other genes implicated in airway pathology. In contrast to the early, transient responses observed for ΔPThighinfection, WT infection induced a prolonged expression of inflammatory genes and increased the extent and duration of lung histopathology. In addition, the administration of purified PT to ΔPThigh-infected mice 1 day after bacterial inoculation exacerbated and prolonged inflammatory responses and airway pathology. These data indicate that PT not only is associated with exacerbated host airway responses during peakB. pertussisinfection but also may inhibit host mechanisms of attenuating and resolving inflammation in the airways, suggesting possible links between PT and pertussis disease symptoms.
Vomiting should be a prompt predictor of stroke outcome
Authors: Shigematsu Kazuo , Shimamura Osamu , Nakano Hiromi , Watanabe Yoshiyuki , Sekimoto Tatsuyuki , Shimizu Kouichiro , Nishizawa Akihiko , Makino Masahiro
Published: September 2012

Background

To predict the outcome of stroke at an acute stage is important but still difficult. Vomiting is one of the commonest symptoms in stroke patients. The aim of this study is threefold: first, to examine the percentage of vomiting in each of the three major categories of strokes; second, to investigate the association between vomiting and other characteristics and third, to determine the correlation between vomiting and mortality.

Methods

We investigated the existence or absence of vomiting in stroke patients in the Kyoto prefecture cohort. We compared the characteristics of patients with and without vomiting. We calculated the HR for death in both types of patients, adjusted for age, sex, blood pressure, arrhythmia, tobacco and alcohol use and paresis.

Results

Of the 1968 confirmed stroke patients, 1349 (68.5%) had cerebral infarction (CI), 459 (23.3%) had cerebral haemorrhage (CH) and 152 (7.7%) had subarachnoid haemorrhage (SAH). Vomiting was seen in 14.5% of all stroke patients. When subdivided according to stroke type, vomiting was observed in 8.7% of CI, 23.7% of CH and 36.8% of SAH cases. HR for death and 95% CI were 5.06 and 3.26 to 7.84 (p<0.001) when all stroke patients were considered, 5.27 and 2.56 to 10.83 (p<0.001) in CI, 2.82 and 1.33 to 5.99 (p=0.007) in CH and 5.07 and 1.87 to 13.76 (p=0.001) in SAH.

Conclusions

Compared with patients without vomiting, the risk of death was significantly higher in patients with vomiting at the onset of stroke. Vomiting should be an early predictor of the outcome.
Competency-based training: who benefits?
Authors: Brightwell Alexandra , Grant Janet
Published: September 2012

Competency based training describes progression through training referenced to the demonstrated ability to perform certain tasks. In recent years, this has become the dominant curriculum model. We seek to examine who benefits from a competency based approach to medical education. For the regulators and service, the apparent advantage is in terms of apparent measurable accountability and flexibility. For assessors, the promise of competence based assessments in the workplace to provide a reliable and objective measurement of a trainee's performance has not been demonstrated in practice. For the doctor in training, there is very little evidence to show benefit from competency based training. Competency based training places emphasis on individual skills rather than overall learning experience thus risks diminishing the role of the trainee in the workplace. Any form of medical education that devalues workplace based learning will ultimately harm the profession and, in turn, patient care.
ABELIAN PRIMITIVE WORDS
Authors: DOMARATZKI MICHAEL , RAMPERSAD NARAD
Published: October 2012

We investigate Abelian primitive words, which are words that are not Abelian powers. We show the set of Abelian primitive words is not context-free. We can determine whether a word is Abelian primitive in linear time (for fixed alphabet size). Also differently from classical primitive words, we find that a word may have more than one Abelian root. We also consider enumeration of Abelian primitive words.
QUANTUM COUNTER AUTOMATA
Authors: CEM SAY A. C. , YAKARYILMAZ ABUZER
Published: October 2012

The question of whether quantum real-time one-counter automata (rtQ1CAs) can outperform their probabilistic counterparts has been open for more than a decade. We provide an affirmative answer to this question, by demonstrating a non-context-free language that can be recognized with perfect soundness by a rtQ1CA. This is the first demonstration of the superiority of a quantum model to the corresponding classical one in the real-time case with an error bound less than 1. We also introduce a generalization of the rtQ1CA, the quantum one-way one-counter automaton (1Q1CA), and show that they too are superior to the corresponding family of probabilistic machines. For this purpose, we provide general definitions of these models that reflect the modern approach to the definition of quantum finite automata, and point out some problems with previous results. We identify several remaining open problems.
POSSIBILITY OF OBSERVING LEPTONIC CP VIOLATION WITH PERTURBED DEMOCRATIC MIXING PATTERNS
Authors: DEEPTHI K. N. , MOHANTA R.
Published: September 2012

The Daya Bay oscillation has recently reported the precise measurement of θ13≃8.8°±0.8° or θ13 ≠0 at 5.2 σ level. The observed nonzero θ13 can be accommodated by some general modifications to the democratic mixing matrix. Using such matrices we study the possibility of observing nonzero CP violation in the leptonic sector.
A UNIFIED THEORY OF MEASUREMENT OF ANISOTROPIC RESISTIVITY BASED ON A SINGLE SURFACE OF ONE (FROM THIN TO THICK) FILM
Authors: HE YUAN , XIANG XIANG , DAI XIANXI , EVENSON WILLIAM E.
Published: September 2012

A unified method and theory for measuring anisotropic resistivity based on a single surface of a film with rapidly converging exact solutions is presented here for solutions appropriate to thin films (Type I solutions) and to thick samples (Type II solutions). Some of the exact solutions of the related simultaneous equation systems can be expressed in terms of elementary functions. The theory proposed here for measuring resistivity of anisotropic crystals is expected to be useful in many applications.
SU(2) COHERENT STATE PATH INTEGRALS LABELED BY A FULL SET OF EULER ANGLES: BASIC FORMULATION
Authors: MATSUMOTO MASAO
Published: September 2012

We develop a basic formulation of the spin (SU(2)) coherent state path integrals based not on the conventional highest or lowest weight vectors but on arbitrary fiducial vectors. The coherent states, being defined on a 3-sphere, are specified by a full set of Euler angles. They are generally considered as states without classical analogues. The overcompleteness relation holds for the states, by which we obtain the time evolution of general systems in terms of the path integral representation; the resultant Lagrangian in the action has a monopole-type term à la Balachandran et al. as well as some additional terms, both of which depend on fiducial vectors in a simple way. The process of the discrete path integrals to the continuous ones is clarified. Complex variable forms of the states and path integrals are also obtained. During the course of all steps, we emphasize the analogies and correspondences to the general canonical coherent states and path integrals that we proposed some time ago. In this paper we concentrate on the basic formulation. The physical applications as well as criteria in choosing fiducial vectors for real Lagrangians, in relation to fictitious monopoles and geometric phases, will be treated in subsequent papers separately.
TESTING POWER-LAW RELAXATION SCENARIOS IN A METASTABLE LIQUID
Authors: GUPTA BHASKAR SEN , DAS SHANKAR P.
Published: September 2012

The renormalized dynamics described by the equations of nonlinear fluctuating hydrodynamics (NFH) treated at one loop order gives rise to the basic model of the mode coupling theory (MCT). We investigate here by analyzing the density correlation function, a crucial prediction of ideal MCT, namely the validity of the multi step relaxation scenario. The equilibrium density correlation function is calculated here from the direct solutions of NFH equations for a hard sphere system. We make first detailed investigation for the robustness of the correlation functions obtained from the numerical solutions by varying the size of the grid. For an optimum choice of grid size we analyze the decay of the density correlation function to identify the multi-step relaxation process. Weak signatures of two step power law relaxation is seen with exponents which do not match predictions from the one loop MCT. For the final relaxation stretched exponential (KWW) behavior is seen and the relaxation time grows with increase of density. But apparent power law divergences indicate a critical packing fraction much higher than the corresponding MCT predictions for a hard sphere fluid.
GROUND STATE OF THE 2D EXTENDED HUBBARD MODEL WITH MORE THAN NEAREST-NEIGHBOR INTERACTIONS
Authors: HARIR S. , BENNAI M. , BOUGHALEB Y.
Published: September 2012

We investigate the ground state phase diagram of the two dimensional Extended Hubbard Model (EHM) with more than Nearest-Neighbor (NN) interactions for finite size system at low concentration. This EHM is solved analytically for finite square lattice at one-eighth filling. All eigenvalues and eigenvectors are given as a function of the on-site repulsion energy U and the off-site interaction energy Vij. The behavior of the ground state energy exhibits the emergence of phase diagram. The obtained results clearly underline that interactions exceeding NN distances in range can significantly influence the emergence of the ground state conductor–insulator transition.
ELECTRICAL CONDUCTIVITY AND DIELECTRIC RELAXATION STUDY OF POLYVINYL ACETATE/POLY METHYL METHACRYLATE BLENDS
Authors: AHMED R. M.
Published: September 2012

Transparent films of PMMA (poly methyl methacrylate), PVAc (polyvinyl acetate) and their blends, have been prepared by using a solution-casting technique. The dielectric properties and the electrical conductivity are reported. The frequency and temperature dependence of the dielectric constant, ε′ and tan δ, have been investigated for the studied samples in the frequency range from 1 kHz to 5 MHz and over a range of temperature from 303–413 K. In addition, AC conductivity values were calculated from the dielectric data and the conduction mechanism is discussed. The frequency-dependent conductivity behavior at different temperatures provides a qualitative description of the conduction mechanism. Also, differential scanning calorimetry (DSC) scans have been measured for the studied samples.
MODULATIONAL INSTABILITY OF A BOSE–EINSTEIN CONDENSATE BEYOND THE FERMI PSEUDOPOTENTIAL WITH A TIME-DEPENDENT COMPLEX POTENTIAL
Authors: BELOBO DIDIER BELOBO , BEN-BOLIE GERMAIN HUBERT , EKOGO THIERRY BLANCHARD , LATCHIO TIOFACK C. G. , KOFANÉ TIMOLÉON CRÉPIN
Published: September 2012

The modulational instability (MI) of Bose–Einstein condensates based on a modified Gross–Pitaevskii equation (GPE) which takes into account quantum fluctuations and a shape-dependent term, trapped in an external time-dependent complex potential is investigated. The external potential consists of an expulsive parabolic background with a complex potential and a gravitational field. The theoretical analysis uses a modified lens-type transformation which converts the modified GPE into a modified form without an explicit spatial dependence. A MI criterion and a growth rate are explicitly derived, both taking into account quantum fluctuations and the parameter related to the feeding or loss of atoms in the condensate which significantly affect the gain of instability of the condensate. Direct numerical simulations of the modified GPE show convincing agreements with analytical predictions. In addition, our numerical results also reveal that the gravitational field has three effects on the MI: (i) the deviation backward or forward of solitons trains, (ii) the enhancement of the appearance of the MI and (iii) the reduction of the lifetime of pulses. Moreover, numerical simulations proved that it is possible to control the propagation of the generated solitons trains by a proper choice of parameters characterizing both the loss or feeding of atoms and the gravitational field, respectively.
UNFOLD SYNCHRONIZATION COMMUNITY STRUCTURE USING MARKOV AND SPECTRAL SIGNATURE
Authors: LI JU , CHEN DIYI , MA XIAOYI , LI HUIJIA
Published: September 2012

Synchronization is a powerful basic rule in nature that regulates a large variety of complex processes, and global synchronization phenomena have been extensively studied for modeling and analyzing the dynamic of systems. Distinct from the existing studies, the work presented here explores the notion of local synchronization phenomenon and their intrinsic properties from the dynamics of a stochastic model defined on a complex network. The relationship between the hierarchical community structure of the network and the local synchronization properties of such a stochastic model has been established based on the famous Kuramoto Model. Critical topological information regarding to the community structures of the network can be inferred from their spectral signatures. Utilizing a novel dynamic system, we have developed an efficient two stages model which can efficiently uncover natural communities hidden in networks in a scalable manner. The effectiveness and efficiency of the algorithm have been theoretically analyzed as well as experimentally validated and it overcomes the inefficiency of the existing methods.
REAL-TIME OBJECT TRACKING ALGORITHM WITH CAMERAS MOUNTED ON MOVING PLATFORMS
Authors: JIANG MING-XIN , SHAO ZHI-JING , WANG HONG-YU
Published: September 2012

Object tracking is one of the key techniques in computer vision. Present algorithms are mainly implemented in static platforms. In this paper, we propose a novel technique for real-time object tracking in videos captured by cameras on moving platforms. First, we rule out feature points that have optical flows inconsistent with those of background. Second, optical flows on the rest of the feature points are utilized to estimate the global motion of the camera. Finally, the kinematic function of particle filtering is modified by the global motion of the camera, together with color-space histogram as appearance model, to achieve robustness in unstable video sequences. The proposed algorithm is tested on several video sequences, compared to mean-shift algorithm and traditional particle filtering tracking, it shows promising real-time tracking performance. Experiments demonstrate that our algorithm can track moving object robustly in videos captured by moving cameras.
ALMOST PERIODIC SOLUTIONS TO STOCHASTIC EVOLUTION EQUATIONS ON BANACH SPACES
Authors: CREWE P.
Published: October 2012

We prove the existence of almost periodic solutions to a class of abstract stochastic evolution equations on a Banach space E, [Formula: see text] Both autonomous (A is a C0-semigroup generator) and non-autonomous (A(t) satisfies conditions of Acquistapace–Terreni and generates a strongly continuous evolution family) cases are studied. Results are based on the theory of stochastic integration on Banach spaces of van Neerven and Weis and R-boundedness estimates for semigroups and evolution families due to Hytönen and Veraar. An example is given for a non-autonomous second order boundary value problem on a domain in ℝd.
ON SOME JORDAN BARIC ALGEBRAS
Authors: ELDUQUE ALBERTO , LABRA ALICIA
Published: October 2012

Several classes of baric algebras studied by different authors will be given a unified treatment, using the technique of gametization. Most of these algebras will be shown, using straightforward arguments, to be either Jordan algebras or closely related to them.
Photosensitized damage of protein by fluorinated diethoxyphosphorus(V)porphyrin
Authors: Hirakawa Kazutaka , Azumi Keito , Nishimura Yoshinobu , Arai Tatsuo , Nosaka Yoshio , Okazaki Segetoshi
Published: October 2012

The effect of the axial ligand fluorination of the water-soluble P(V)porphyrin complex on photosensitized protein damage was examined. The activity of singlet oxygen generation by diethoxyP(V) porphyrin was slightly improved by the fluorination of the ethoxy chains. Absorption spectrum measurements demonstrated the binding interaction between the P(V)porphyrins and human serum albumin, a water-soluble protein. Photo-irradiated P(V)porphyrins damaged the amino acid residue of human serum albumin, resulting in the decrease of the fluorescence intensity from the tryptophan residue of human serum albumin. A singlet oxygen quencher, sodium azide, could not completely inhibit the damage of human serum albumin, suggesting that the electron transfer mechanism contributes to protein damage as does singlet oxygen generation. The decrease of the fluorescence lifetime of P(V)porphyrin by human serum albumin supported the electron transfer mechanism. The estimated contributions of the electron transfer mechanism are 0.57 and 0.44 for the fluorinated and non-fluorinated P(V)porphyrins, respectively. The total quantum yield of the protein photo-oxidation was slightly enhanced by this axial fluorination.
Oxygen Diffusion Phenomena and Hydrogen Incorporation in Reducing BaTiO3 Ceramics Doped with Ho below Solubility Limit
Authors: Sakaguchi Isao , Watanabe Ken , Hishita Shunichi , Ohashi Naoki , Haneda Hajime
Published: September 2012

Oxygen diffusion phenomena in BaTiO3 ceramics doped with Ho of 5.2 ×1018/cm3 were studied in order to reveal the effect of reduction thermal annealing. The samples were reduced at 850 °C in a 3% H2–Ar atmosphere before the oxygen diffusion experiments. The oxygen diffusion was carried out in the temperature range of 700–800 °C. The measurement of diffusion profiles and ion images revealed the oxygen defect distribution caused by the annealing. The results show that the grain boundary acts as a layer blocking oxygen diffusion when the diffusion temperature is below the reduction temperature of 850 °C.
Strong Light-Extraction Enhancement of GaN-Based Light-Emitting Diodes with Top and Sidewall GaOOH Nanorod Arrays
Authors: Lee Hee Kwan , Yu Jae Su
Published: September 2012

We reported the gallium nitride-based blue light-emitting diodes (LEDs) with top and sidewall gallium oxide hydroxide (GaOOH) nanorod arrays (NRAs). Highly-oriented GaOOH NRAs were formed on the surfaces of LEDs by the electrochemical deposition method using a sputtered tin oxide seed layer. The as-synthesized GaOOH NRAs exhibited a high light-scattering property while maintaining high transparency of >90% in the visible wavelength range. For LEDs with top and sidewall GaOOH NRAs, the light output power was significantly enhanced by ∼36% and the far-field radiation pattern also became wider compared to the conventional LED. This improvement in light extraction is attributed to the relatively graded refractive index profile and the formation of roughened top and sidewall surfaces by the GaOOH NRAs.
Fabrication of ZnS0.6Se0.4Nanowires Using ZnS Nanowires as an In-situ Template
Authors: Zhong Ping , Wang Chunrui , Xu Jing , Wang Hongyun , Xu Xiaofeng , Xin Huaizhong , Chen Xiaoshuang
Published: September 2012

Single-crystalline ZnS0.6Se0.4was synthesized by thermal evaporation without a metallic catalyst. The as-prepared ZnS0.6Se0.4nanowires with a rough surface and a larger diameter were in contrast to the as-prepared ZnS nanowires. The growth mechanism for ZnS0.6Se0.4ZnS nanowires appears to be reasonably explained by the vapor–solid growth mechanism involved in ZnS nanowires, which serve asin-situsource templates. The cathodoluminescence properties of ZnS0.6Se0.4reveal a broad emission band. The emission band of ZnS0.6Se0.4nanowires exhibits a redshift in comparison with that of ZnS nanowires.
Etching Characteristics and Mechanisms of TiO2 Thin Films in HBr/Cl2/Ar Inductively Coupled Plasma
Authors: Kim Daehee , Efremov Alexander , Jang Hanbyeol , Kang Sungchil , Yun Sun Jin , Kwon Kwang-Ho
Published: September 2012

The TiO2 etching characteristics and mechanism in HBr/Cl2/Ar inductively coupled plasma (with a fixed bias power of 200 W) were investigated. It was found that the TiO2 etching rate in Cl2/Ar plasma is about 8 times faster than that in HBr/Ar plasma. In both HBr-rich (60% HBr + 20% Cl2 + 20% Ar) and Cl2-rich (20% HBr + 60% Cl2 + 20% Ar) plasmas, an increase in gas pressure (4–10 mTorr) results in a non-monotonic increase in TiO2 etching rate, while the variation of input power (500–800 W) causes a monotonic acceleration of the etching process. Plasma diagnostics by Langmuir probes and zero-dimensional plasma modeling provided data on plasma parameters, steady-state densities, and fluxes of active species on the etched surface. The model-based analysis of the TiO2 etching kinetics shows a transitional regime of ion-assisted chemical reaction with domination of a chemical etching pathway.
Relativized Worlds without Worst-Case to Average-Case Reductions for NP
Authors: Watson Thomas
Published: October 2012

We prove that, relative to an oracle, there is no worst-case to average-case reduction for NP. We also handle classes that are somewhat larger than NP, as well as worst-case to
errorless
-average-case reductions. In fact, we prove that relative to an oracle, there is no worst-case to errorless-average-case reduction from NP to BPP
∥
NP
. We also handle reductions from NP to the polynomial-time hierarchy and beyond, under strong restrictions on the number of queries the reductions can make.
Potential of Insects as Food and Feed in Assuring Food Security
Authors: van Huis Arnold
Published: September 2012

With a growing world population and increasingly demanding consumers, the production of sufficient protein from livestock, poultry, and fish represents a serious challenge for the future. Approximately 1,900 insect species are eaten worldwide, mainly in developing countries. They constitute quality food and feed, have high feed conversion ratios, and emit low levels of greenhouse gases. Some insect species can be grown on organic side streams, reducing environmental contamination and transforming waste into high-protein feed that can replace increasingly more expensive compound feed ingredients, such as fish meal. This requires the development of cost-effective, automated mass-rearing facilities that provide a reliable, stable, and safe product. In the tropics, sustainable harvesting needs to be assured and rearing practices promoted, and in general, the food resource needs to be revalorized. In the Western world, consumer acceptability will relate to pricing, perceived environmental benefits, and the development of tasty insect-derived protein products.
Vision in Drosophila: Seeing the World Through a Model's Eyes
Authors: Paulk Angelique , Millard S. Sean , van Swinderen Bruno
Published: September 2012

The fruit fly, Drosophila melanogaster, has been used for decades as a genetic model for unraveling mechanisms of development and behavior. In order to efficiently assign gene functions to cellular and behavioral processes, early measures were often necessarily simple. Much of what is known of developmental pathways was based on disrupting highly regular structures, such as patterns of cells in the eye. Similarly, reliable visual behaviors such as phototaxis and motion responses provided a solid foundation for dissecting vision. Researchers have recently begun to examine how this model organism responds to more complex or naturalistic stimuli by designing novel paradigms that more closely mimic visual behavior in the wild. Alongside these advances, the development of brain-recording strategies allied with novel genetic tools has brought about a new era of Drosophila vision research where neuronal activity can be related to behavior in the natural world.
Implications of the Dodd-Frank Act*
Authors: Acharya Viral V. , Richardson Matthew
Published: September 2012

In this review, we provide an economic assessment of the Dodd-Frank Act of 2010 in terms of the likely efficacy of the financial-sector regulation it proposes. We focus in particular on its ability to contain systemic risk, the risk that many financial firms may fail en masse, and discuss the tools it employs. Namely, we examine enhanced capital requirements for systemically important financial firms, the separation of proprietary trading from bank holding companies (the Volcker rule), the resolution authority for orderly management of large complex financial institution (LCFI) failure, and attempts to contain risks in the shadow banking system. We relate the Act to its most important predecessor, the Banking Act of 1933, and consider the desirability and implications of the Dodd-Frank Act's all-encompassing approach to the reform of financial-sector architecture and regulation.