bluuebunny/crossref_metadata_2025 huggingface dataset:
Genetic Counseling: A Transnational Perspective
Authors: Elackatt Niby J.
Published: May 2013

Although the basic goal and components of genetic counseling appears to be the same across the globe, judged by my experiences there are significant differences in the provision of genetic counseling services in Australasia (Australia and New Zealand) and India. There is poor recognition of the professional status of a genetic counselor in India at present. This may be partly because genetic counseling itself is a relatively new discipline within the medical field in India, although some types of genetic services and research have been conducted since 1960s. In this paper, I aim to provide insight from my personal transnational experiences.
Ethnicity and bullying involvement in a national UK youth sample
Authors: Tippett Neil , Wolke Dieter , Platt Lucinda
Published: May 2013

This study investigated ethnic differences in bullying involvement (as victim and bully) among a UK wide sample of adolescents, controlling for potential confounders, including age, gender, economic situation, family structure and parent–adolescent relationships. 4668 youths, aged 10 to 15, who participate in the UK Household Longitudinal Study were assessed for bullying involvement. Binary logistic regression models were used to estimate ethnic differences across bullying roles while controlling for potential confounders. Overall, ethnic minority youths were not more likely to be victims; African boys and girls were significantly less likely to be victimised than same sex White youths. Pakistani and Caribbean girls were significantly more likely to have bullied others compared to White girls.

Further research is necessary to explore why Pakistani and Caribbean girls may be more often perpetrators of bullying than girls in other ethnic groups.
The Mpn1 RNA exonuclease: Cellular functions and implication in disease
Authors: Shchepachev Vadim , Azzalin Claus M.
Published: May 2013

Recent studies from independent laboratories have decisively disclosed the identity of the long‐sought 3–5′ RNA exonuclease that trims posttranscriptionally the oligouridine tail of U6, which is the small catalytic non‐coding RNA promoting premRNA splicing within the spliceosome. This exonuclease, dubbed Mpn1 or Usb1, is a highly conserved enzyme that specifically removes uridines from the 3′ end of U6, and directly generates terminal 2′,3′ cyclic phosphate groups. Mutations in the human gene encoding hMpn1 have been reported in patients diagnosed with the rare genodermatosis Clericuzio‐type poikiloderma with neutropenia (PN). Mpn1‐associated functions in U6 small nuclear RNA posttranscriptional regulation suggest the existence of sophisticated cellular pathways involved in surveillance and stabilization of U6. In this light, PN pathology might turn out to be a consequence of disturbed quality control of RNAs involved in crucial biological events.
Functional interrogation of kinases and other nucleotide‐binding proteins
Authors: Rosenblum Jonathan S. , Nomanbhoy Tyzoon K. , Kozarich John W.
Published: May 2013

The largest mammalian enzyme family is the kinases. Kinases and other nucleotide‐binding proteins are key regulators of signal transduction pathways and the mutation or overexpression of these proteins is often the difference between health and disease. As a result, a massive research effort has focused on understanding how these proteins function and how to inhibit them for therapeutic benefit. Recent advances in chemical biological tools have enabled functional interrogation of these enzymes to provide a deeper understanding of their physiological roles. In addition, these innovative platforms have paved the way for a new generation of drugs whose properties have been guided by functional profiling.
Pharmacological protein targets in polyglutamine diseases: Mutant polypeptides and their interactors
Authors: Margulis Boris A. , Vigont Vladimir , Lazarev Vladimir F. , Kaznacheyeva Elena V. , Guzhova Irina V.
Published: May 2013

Polyglutamine diseases are a group of pathologies affecting different parts of the brain and causing dysfunction and atrophy of certain neural cell populations. These diseases stem from mutations in various cellular genes that result in the synthesis of proteins with extended polyglutamine tracts. In particular, this concerns huntingtin, ataxins, and androgen receptor. These mutant proteins can form oligomers, aggregates, and, finally, aggresomes with distinct functions and different degrees of cytotoxicity. In this review, we analyze the effects of different forms of polyQ proteins on other proteins and their functions, which are considered as targets for therapeutic intervention.
Initial credit ratings and earnings management
Authors: Demirtas K. Ozgur , Rodgers Cornaggia Kimberly
Published: May 2013

Credit rating agencies assert that they rely on financial information provided by issuers and that they value rating stability as well as accuracy. In an environment where rating agencies depend on issuer‐reported information and are reluctant to adjust ratings promptly, managers of issuing firms can utilize the discretion afforded by GAAP to obtain the most favorable credit ratings. Consistent with our expectations, we find that current accruals are unusually positive and high around initial credit ratings. The increase in abnormally high accruals leading up to the initial credit rating year is followed by a reversal in the subsequent years. Multivariate regression analyses suggest that accounting accruals, abnormal current accruals in particular, are significantly positively related to initial credit ratings after controlling for several issue‐ and issuer‐related characteristics indicative of default risk. Our results are robust to additional tests that account for endogeneity between credit ratings and earnings management, adjust for performance, and account for firms issuing debt and equity simultaneously.
Emergency Response to Mass Casualty Incidents in Lebanon
Authors: El Sayed Mazen J.
Published: May 2013

The emergency response to mass casualty incidents in Lebanon lacks uniformity. Three recent large-scale incidents have challenged the existing emergency response process and have raised the need to improve and develop incident management for better resilience in times of crisis. We describe some simple emergency management principles that are currently applied in the United States. These principles can be easily adopted by Lebanon and other developing countries to standardize and improve their emergency response systems using existing infrastructure. (Disaster Med Public Health Preparedness. 2013;0:1–6)
On the wetting dynamics in a Couette flow
Authors: Gao Peng , Lu Xi-Yun
Published: May 2013

The dynamics of moving contact lines in a two-phase Couette flow is investigated by using a matched asymptotic procedure. The walls are assumed to be partially wetting, and the microscopic contact angle is finite but sufficiently small so that the lubrication approach can be used. Explicit formulas are derived to characterize the shear-induced interface deformation and the critical capillary number for the onset of wetting transition. It is found that the apparent contact angle vanishes for liquid–air systems and remains finite for liquid–liquid systems when the wetting transition occurs.
Blackness, Indigeneity, Multiculturalism and Genomics in Brazil, Colombia and Mexico
Authors: WADE PETER
Published: May 2013

Genomic research in Latin America has looked into the African, Amerindian and European ancestry of local populations. This article explores how indigeneity and blackness figure in genomic science in the light of previous and current representations of indigenous and Afro-descendent people. These categories have been cast as ‘other’ in Latin America, but they have occupied different locations in ‘structures of alterity’. I look briefly at these similarities and differences in the colonial and republican periods and in recent multiculturalist reforms. I look at the gendered sexual imagery surrounding each concept, before examining in detail how blackness and indigeneity figure in gendered ways in genomic science research on admixture and ancestry in Brazil, Colombia and Mexico. I conclude that, in the context of multiculturalism, genomics works to re-centre imaginaries of the nation around the mestizo and mixture, while casting blackness and indigeneity, in sexualised and gendered ways, as different kinds of others.
The Bolivian Revolution at 60: Politics and Historiography
Authors: DUNKERLEY JAMES
Published: May 2013

The 60th anniversary of the Bolivian Revolution of 1952 led by the MNR provided an opportunity to review a Latin American political experience of disputed importance in the light of the government of the MAS under Evo Morales since 2006. This essay reappraises the historiography of 1952 from the perspective of MNR officialism and from critical positions, particularly those associated withindigenismoor Katarismo.Bolivia hoy, an influential collection of essays edited by René Zavaleta Mercado in 1983, is identified as a key moment in changing interpretations of the 1952 revolution.
Depression is related to an absence of optimistically biased belief updating about future life events
Authors: Korn C. W. , Sharot T. , Walter H. , Heekeren H. R. , Dolan R. J.
Published: May 2013

Background

When challenged with information about the future, healthy participants show an optimistically biased updating pattern, taking desirable information more into account than undesirable information. However, it is unknown how patients suffering from major depressive disorder (MDD), who express pervasive pessimistic beliefs, update their beliefs when receiving information about their future. Here we tested whether an optimistically biased information processing pattern found in healthy individuals is absent in MDD patients.

Method

MDD patients (n = 18; 13 medicated; eight with co-morbid anxiety disorder) and healthy controls (n = 19) estimated their personal probability of experiencing 70 adverse life events. After each estimate participants were presented with the average probability of the event occurring to a person living in the same sociocultural environment. This information could be desirable (i.e. average probability better than expected) or undesirable (i.e. average probability worse than expected). To assess how desirable versus undesirable information influenced beliefs, participants estimated their personal probability of experiencing the 70 events a second time.

Results

Healthy controls showed an optimistic bias in updating, that is they changed their beliefs more toward desirable versus undesirable information. Overall, this optimistic bias was absent in MDD patients. Symptom severity correlated with biased updating: more severely depressed individuals showed a more pessimistic updating pattern. Furthermore, MDD patients estimated the probability of experiencing adverse life events as higher than healthy controls.

Conclusions

Our findings raise the intriguing possibility that optimistically biased updating of expectations about one's personal future is associated with mental health.
Syndromic surveillance for local outbreak detection and awareness: evaluating outbreak signals of acute gastroenteritis in telephone triage, web-based queries and over-the-counter pharmacy sales
Authors: ANDERSSON T. , BJELKMAR P. , HULTH A. , LINDH J. , STENMARK S. , WIDERSTRÖM M.
Published: May 2013

For the purpose of developing a national system for outbreak surveillance, local outbreak signals were compared in three sources of syndromic data – telephone triage of acute gastroenteritis, web queries about symptoms of gastrointestinal illness, and over-the-counter (OTC) pharmacy sales of antidiarrhoeal medication. The data sources were compared against nine known waterborne and foodborne outbreaks in Sweden in 2007–2011. Outbreak signals were identified for the four largest outbreaks in the telephone triage data and the two largest outbreaks in the data on OTC sales of antidiarrhoeal medication. No signals could be identified in the data on web queries. The signal magnitude for the fourth largest outbreak indicated a tenfold larger outbreak than officially reported, supporting the use of telephone triage data for situational awareness. For the two largest outbreaks, telephone triage data on adult diarrhoea provided outbreak signals at an early stage, weeks and months in advance, respectively, potentially serving the purpose of early event detection. In conclusion, telephone triage data provided the most promising source for surveillance of point-source outbreaks.
Can we achieve high uptakes of influenza vaccination of healthcare workers in hospitals? A cross-sectional survey of acute NHS trusts in England
Authors: EDELSTEIN M. , PEBODY R.
Published: May 2013

It is unknown which intervention strategies are used or effective to increase influenza vaccine uptake by healthcare workers (HCWs) in acute hospitals in England. We undertook a survey in acute hospitals, described strategies employed from 2008 to 2012 and used multivariable binomial regression to identify those effective. Eighty out of 166 trusts responded and reported 25 strategies. Every intervention showed increased use: peer vaccination from 3·8% to 38·8% (+921%); educational DVDs from 3·8% to 22·5% (+492%); Twitter from 2·5% to 12·5% (+400%) and Facebook from 1·3% to 6·3% (+384%). Peer vaccination increased uptake by 7·3% [95% confidence interval (CI) 1·1–13·6,P = 0·02] overall; educational DVDs by 9·7% overall (95% CI 1·8–17·6,P = 0·02), 11·9% in non-doctor, non-nurse HCWs (95% CI 0·9–22·8,P = 0·03). For doctors, using a champion doctor increased uptake by 17·8% (95% CI 7·6–28·0,P < 0·01). No intervention increased uptake by nurses. Increasing uptake requires multi-intervention strategies targeted at different HCW groups.
ITALY'S INDUSTRIAL GREAT DEPRESSION: FASCIST PRICE AND WAGE POLICIES
Authors: Giordano Claire , Piga Gustavo , Trovato Giovanni
Published: May 2013

Industrial production and employment in Italy were hard hit by the Great Depression, and remained below trend until at least 1936. Few quantitative studies have been conducted on the causes of Italy's recession and slow recovery. Using monthly data, and reviving an aggregate supply model published in Bernanke and Carey [Quarterly Journal of Economics111 (1996), 853–883], we empirically test whether Italy's 1930s industrial performance could be related to the Fascist wage and price policies, which, aiming at keeping workers' real wages constant, actually raised firms' labor costs, computed as nominal wages deflated by wholesale prices, hence stalling industrial production. We find evidence of a strong countercyclicality of real wages and of nominal wage stickiness in the period 1929–1936, which would confirm our hypothesis. Trade restrictions are found to play a smaller role in hindering industrial production than previously stated in the literature, whereas we confirm the weak transmission of financial turbulence to the real economy.
Development and Evaluation of a Novel Topical Treatment for Acne with Azelaic Acid-Loaded Nanoparticles
Authors: Reis Catarina Pinto , Gomes Ana , Rijo Patrícia , Candeias Sara , Pinto Pedro , Baptista Marina , Martinho Nuno , Ascensão Lia
Published: May 2013

Azelaic acid (AzA) is used in the treatment of acne. However, side effects and low compliance have been associated with several topical treatments with AzA. Nanotechnology presents a strategy that can overcome these problems. Polymeric nanoparticles can control drug release and targeting and reduce local drug toxicity. The aim of this study was to produce and evaluate an innovative topical treatment for acne with AzA-loaded poly-dl-lactide/glycolide copolymer nanoparticles. A soft white powder of nanoparticles was prepared. The mean size of loaded nanoparticles was <400 nm and zeta potential was negative. Spherical nanoparticles were observed by scanning electron microscopy. Encapsulation efficiency was around 80% and a strong interaction between the polymer and the drug was confirmed by differential scanning calorimetric analysis. In vitro drug release studies suggested a controlled and pulsatile release profile. System efficacy tests suggested similar results between the loaded nanoparticles and the nonencapsulated drug against the most common bacteria associated with acne. Cytotoxicity of AzA-loaded nanoparticles was concentration dependent, although not pronounced. The occluded patch test seemed to indicate that the formulation excipients were safe and thus AzA-loaded nanoparticles appear to be an efficient and safe treatment for acne.
On the probability of habitable planets
Authors: Forget François
Published: May 2013

In the past 15 years, astronomers have revealed that a significant fraction of the stars should harbour planets and that it is likely that terrestrial planets are abundant in our galaxy. Among these planets, how many are habitable, i.e. suitable for life and its evolution? These questions have been discussed for years and we are slowly making progress. Liquid water remains the key criterion for habitability. It can exist in the interior of a variety of planetary bodies, but it is usually assumed that liquid water at the surface interacting with rocks and light is necessary for emergence of a life able to modify its environment and evolve. The first key issue is thus to understand the climatic conditions allowing surface liquid water assuming a suitable atmosphere. These have been studied with global mean one-dimensional (1D) models which have defined the ‘classical habitable zone’, the range of orbital distances within which worlds can maintain liquid water on their surfaces (Kasting et al. 1993). A new generation of 3D climate models based on universal equations and tested on bodies in the solar system are now available to explore with accuracy climate regimes that could locally allow liquid water. The second key issue is now to better understand the processes which control the composition and the evolution of the atmospheres of exoplanets, and in particular the geophysical feedbacks that seem to be necessary to maintain a continuously habitable climate. From that point of view, it is not impossible that the Earth's case may be special and uncommon.
NONASSOCIATIVE SUBSTRUCTURAL LOGICS AND THEIR SEMILINEAR EXTENSIONS: AXIOMATIZATION AND COMPLETENESS PROPERTIES
Authors: CINTULA PETR , HORČÍK ROSTISLAV , NOGUERA CARLES
Published: May 2013

Substructural logics extending the full Lambek calculus FL have largely benefited from a systematical algebraic approach based on the study of their algebraic counterparts: residuated lattices. Recently, a nonassociative generalization of FL (which we call SL) has been studied by Galatos and Ono as the logic of lattice-ordered residuated unital groupoids. This paper is based on an alternative Hilbert-style presentation for SL which is almost MP-based. This presentation is then used to obtain, in a uniform way applicable to most (both associative and nonassociative) substructural logics, a form of local deduction theorem, description of filter generation, and proper forms of generalized disjunctions. A special stress is put on semilinear substructural logics (i.e., logics complete with respect to linearly ordered algebras). Axiomatizations of the weakest semilinear logic over SL and other prominent substructural logics are provided and their completeness with respect to chains defined over the real unit interval is proved.
Brain Alanine Formation as an Ammonia-Scavenging Pathway during Hyperammonemia: Effects of Glutamine Synthetase Inhibition in Rats and Astrocyte—Neuron Co-Cultures
Authors: Dadsetan Sherry , Kukolj Eva , Bak Lasse K , SØrensen Michael , Ott Peter , Vilstrup Hendrik , Schousboe Arne , Keiding Susanne , Waagepetersen Helle S
Published: May 2013

Hyperammonemia is a major etiological toxic factor in the development of hepatic encephalopathy. Brain ammonia detoxification occurs primarily in astrocytes by glutamine synthetase (GS), and it has been proposed that elevated glutamine levels during hyperammonemia lead to astrocyte swelling and cerebral edema. However, ammonia may also be detoxified by the concerted action of glutamate dehydrogenase (GDH) and alanine aminotransferase (ALAT) leading to trapping of ammonia in alanine, which in vivo likely leaves the brain. Our aim was to investigate whether the GS inhibitor methionine sulfoximine (MSO) enhances incorporation of 15NH4+ in alanine during acute hyperammonemia. We observed a fourfold increased amount of 15NH4 incorporation in brain alanine in rats treated with MSO. Furthermore, co-cultures of neurons and astrocytes exposed to 15NH4Cl in the absence or presence of MSO demonstrated a dose-dependent incorporation of 15NH4 into alanine together with increased 15N incorporation in glutamate. These findings provide evidence that ammonia is detoxified by the concerted action of GDH and ALAT both in vivo and in vitro, a mechanism that is accelerated in the presence of MSO thereby reducing the glutamine level in brain. Thus, GS could be a potential drug target in the treatment of hyperammonemia in patients with hepatic encephalopathy.
Extra Permeability is Required to Model Dynamic Oxygen Measurements: Evidence for Functional Recruitment?
Authors: Barrett Matthew JP , Suresh Vinod
Published: May 2013

Neural activation triggers a rapid, focal increase in blood flow and thus oxygen delivery. Local oxygen consumption also increases, although not to the same extent as oxygen delivery. This ‘uncoupling’ enables a number of widely-used functional neuroimaging techniques; however, the physiologic mechanisms that govern oxygen transport under these conditions remain unclear. Here, we explore this dynamic process using a new mathematical model. Motivated by experimental observations and previous modeling, we hypothesized that functional recruitment of capillaries has an important role during neural activation. Using conventional mechanisms alone, the model predictions were inconsistent with in vivo measurements of oxygen partial pressure. However, dynamically increasing net capillary permeability, a simple description of functional recruitment, led to predictions consistent with the data. Increasing permeability in all vessel types had the same effect, but two alternative mechanisms were unable to produce predictions consistent with the data. These results are further evidence that conventional models of oxygen transport are not sufficient to predict dynamic experimental data. The data and modeling suggest that it is necessary to include a mechanism that dynamically increases net vascular permeability. While the model cannot distinguish between the different possibilities, we speculate that functional recruitment could have this effect in vivo.
A Time to Event Tutorial for Pharmacometricians
Authors: Holford Nick
Published: May 2013

Models for time to event provide the link between standard pharmacokinetic–dynamic models disease progression, and clinical outcome events. The biological basis for events may be expressed quantitatively in terms of a hazard function. This tutorial explains hazards and how doses can be linked to events predicted from hazard functions.

CPT: Pharmacometrics & Systems Pharmacology (2013) 2, e43; doi:10.1038/psp.2013.18; advance online publication 15 May 2013
STIM1 negatively regulates Ca2+ release from the sarcoplasmic reticulum in skeletal myotubes
Authors: Lee Keon Jin , Woo Jin Seok , Hwang Ji-Hye , Hyun Changdo , Cho Chung-Hyun , Kim Do Han , Lee Eun Hui
Published: May 2013

STIM1 (stromal interaction molecule 1) mediates SOCE (store-operated Ca2+ entry) in skeletal muscle. However, the direct role(s) of STIM1 in skeletal muscle, such as Ca2+ release from the SR (sarcoplasmic reticulum) for muscle contraction, have not been identified. The times required for the maximal expression of endogenous STIM1 or Orai1, or for the appearance of puncta during the differentiation of mouse primary skeletal myoblasts to myotubes, were all different, and the formation of puncta was detected with no stimulus during differentiation, suggesting that, in skeletal muscle, the formation of puncta is a part of the differentiation. Wild-type STIM1 and two STIM1 mutants (Triple mutant, missing Ca2+-sensing residues but possessing the intact C-terminus; and E136X, missing the C-terminus) were overexpressed in the myotubes. The wild-type STIM1 increased SOCE, whereas neither mutant had an effect on SOCE. It was interesting that increases in the formation of puncta were observed in the Triple mutant as well as in wild-type STIM1, suggesting that SOCE-irrelevant puncta could exist in skeletal muscle. On the other hand, overexpression of wild-type or Triple mutant, but not E136X, attenuated Ca2+ releases from the SR in response to KCl [evoking ECC (excitation–contraction coupling) via activating DHPR (dihydropyridine receptor)] in a dominant-negative manner. The attenuation was removed by STIM1 knockdown, and STIM1 was co-immunoprecipitated with DHRP in a Ca2+-independent manner. These results suggest that STIM1 negatively regulates Ca2+ release from the SR through the direct interaction of the STIM1 C-terminus with DHPR, and that STIM1 is involved in both ECC and SOCE in skeletal muscle.
Spermidine promotes adipogenesis of 3T3-L1 cells by preventing interaction of ANP32 with HuR and PP2A
Authors: Hyvönen Mervi T. , Koponen Taina , Weisell Janne , Pietilä Marko , Khomutov Alex R. , Vepsäläinen Jouko , Alhonen Leena , Keinänen Tuomo A.
Published: May 2013

We have shown previously that the polyamine spermidine is indispensable for differentiation of 3T3-L1 preadipocytes. In the present study, we examined the mechanism of spermidine function by using the polyamine biosynthesis inhibitor α-difluoromethylornithine in combination with the metabolically stable polyamine analogues γ-methylspermidine or (R,R)-α,ω-bismethylspermine. At the early phase of differentiation, spermidine-depleted 3T3-L1 cells showed decreased translation of the transcription factor C/EBPβ (CCAAT/enhancer-binding protein β), decreased PP2A (protein phosphatase 2A) activity and increased cytoplasmic localization of the RNA-binding protein HuR (human antigen R). The amount of HuR bound to C/EBPβ mRNA was reduced, whereas the amount of bound CUGBP2, an inhibitor of C/EBPβ translation, was increased. ANP32 (acidic nuclear phosphoprotein 32) proteins, which are known PP2A inhibitors and HuR ligands, bound more PP2A and HuR in spermidine-depleted than in control cells, whereas immunodepletion of ANP32 proteins from the lysate of spermidine-depleted cells restored PP2A activity. Taken together, our data shows that spermidine promotes C/EBPβ translation in differentiating 3T3-L1 cells, and that this process is controlled by the interaction of ANP32 with HuR and PP2A.
Normal Cognitive Aging and Mild Cognitive Impairment: Drawing the Fine Line
Authors: Fleming Valarie B.
Published: May 2013

Mild cognitive impairment (MCI) is a transitional diagnostic category between normal cognitive aging and dementia. Speech-language pathologists (SLPs) have a role in the management of MCI, particularly the assessment and treatment of cognitive-communicative impairments related to MCI. The difficulty lies in distinguishing between normal cognitive aging and pathological aging. SLPs will need to be equipped with knowledge regarding the neurobiological, cognitive, and cognitive-communicative changes occurring in both normal and pathological aging, specifically the alterations arising in MCI.
Kernel least absolute shrinkage and selection operator regression classifier for pattern classification
Authors: Xu Jie , Yin Jun
Published: May 2013

The feature vectors in feature space are more likely to be linearly separable than the observations in input space. To enhance the separability of the feature vectors, the authors perform least absolute shrinkage and selection operator (LASSO) regression in the reproducing kernel Hilbert space and develop a kernel LASSO regression classifier (LASSO‐KRC). Based on the theory of calculus, least squares optimisation with L1‐norm regularised constraints can be reformulated into another equivalent form. Without an explicit mapping function, the solution to the optimisation problem can be obtained by solving a convex optimisation problem with any symmetric kernel function. LASSO‐KRC is applied to pattern classification and appears to outperform nearest neighbour classifier, minimum distance classifier, sparse representation classifier and linear regression classifier.
Improved complete neighbourhood preserving embedding for face recognition
Authors: Lu Gui‐Fu , Wang Yong , Zou Jian
Published: May 2013

Complete neighbourhood preserving embedding (CNPE) is a recently proposed approach to overcome the drawbacks of neighbourhood preserving embedding (NPE) which is difficult to directly apply to face recognition because of computational complexity. However, there are still disadvantages for CNPE: (i) CNPE is time‐consuming when N is large, here N is the sample size; (ii) the solutions of CNPE may suffer from the degenerate eigenvalue problem, that is, several eigenvectors with the same maximal eigenvalue, which make them not optimal in terms of the discriminant ability. In this study, the authors proposed a new approach, namely improved complete neighbourhood preserving (ICNPE), to address the drawbacks of CNPE. ICNPE is more efficient than CNPE and can overcome the degenerate eigenvalue problem of CNPE. Experiments on the Olivetti & Oracle Research Laboratory (ORL), Yale, PIE (pose, illumination and expression) and Alex Martinez and Robert Benavente (AR) face databases show the effectiveness of the proposed ICNPE.
Reliability evaluation of restructured power systems using a novel optimal power‐flow‐based approach
Authors: Mehrtash Amir , Wang Peng , Goel Lalit
Published: May 2013

Power system planning and operation has been considerably affected by restructuring of power systems and high penetration of renewable energy resources. In the new environment, customers are at the centre of attention and their concerns need to be addressed properly. The conventional techniques are not usually able to address both segregation of power system components and uncertainty of renewable energy resources. A novel technique is proposed in this study to determine load point reliability in restructured power systems considering the effect of renewable generators. This technique is based on modified optimal power flow and represents generation and transmission system with their equivalent multistate models and investigates the effect of each one on the load point reliability, separately. Furthermore, this approach remarkably relieves the reliability evaluation process, especially when loads and generations are subject to changes in the power system. The proposed method can assist the planners in reaching an optimal load allocation plan by providing valuable information. The proposed approach is applied to the Roy Billinton test system to illustrate the applications and advantages of the new approach.
Research on lightning performance of AC/DC hybrid transmission lines on the same tower
Authors: Wei Shi , Qingmin Li , Liang Zou , Li Zhang , Xinchang Lu
Published: May 2013

Rapid expansion of power system and the limitation of transmission corridor resources have indispensably promoted the development of AC/DC hybrid transmission lines on the same tower under special situations, especially for ultra‐high voltage systems being established in China. A hybrid tower model incorporating a double‐circuit AC transmission and a bipolar DC transmission is proposed in the study. The lightning performance of AC/DC hybrid transmission lines is investigated based on electro‐magnetic transient program (EMTP) and leader progression model, taking into account the operating voltage of transmission lines as well as the competition of multiple upward leaders. The impact of tower's height, footing resistance, arrangements of ground wires and ground obliquity on lightning protection performance is also analysed. In accordance with the ± 800 kV bipolar DC and the 500 kV double‐circuit AC transmission lines on the same tower, the results show that the back flashover and the shielding failure is relatively serious for a 500 kV AC transmission line, which should be paid more attention to. Finally, several methods that may be used to improve lightning protection performance of the AC/DC hybrid transmission lines are presented, such as reducing the tower's height, using a negative protection angle and installing additional ground wires.
Non‐ideal iris segmentation using anisotropic diffusion
Authors: Wan Hong‐Lin , Li Zhi‐Cheng , Qiao Jian‐Ping , Li Bao‐Sheng
Published: May 2013

Iris segmentation is critical for iris recognition. In this study, the authors present a circle‐based iris segmentation method for non‐ideally captured iris by employing anisotropic diffusion. Our proposal consists of two component steps by which interior and exterior boundaries are localised, respectively. To save computational load, Laplace pyramid (LP) framework is incorporated into both steps. During the first step, when iris has been decomposed into the coarse level by LP, reflections will be removed by anisotropic diffusion and morphologic operations. In the second step, the authors present the innovated curve evolution to detect exterior boundary. Moreover, order statistical filters are employed to enhance the contrast of iris and sclera. Experimental results depict a high correct ratio of segmentation that is more than 96.90% thereby validating the proposed approach.
Detection of hard exudates from diabetic retinopathy images using fuzzy logic
Authors: Ranamuka Nayomi Geethanjali , Meegama Ravinda Gayan N.
Published: May 2013

Diabetic retinopathy (DR), that affects the blood vessels of the human retina, is considered to be the most serious complication prevalent among diabetic patients. If detected successfully at an early stage, the ophthalmologist would be able to treat the patients by advanced laser treatment to prevent total blindness. In this study, the authors propose a technique based on morphological image processing and fuzzy logic to detect hard exudates from DR retinal images. At the initial stage, the exudates are identified using mathematical morphology that includes elimination of the optic disc. Subsequently, hard exudates are extracted using an adaptive fuzzy logic algorithm that uses values in the RGB colour space of retinal image to form fuzzy sets and membership functions. The fuzzy output for all the pixels in every exudate is calculated for a given input set corresponding to red, green and blue channels of a pixel in an exudate. This fuzzy output is computed for hard exudates according to the proportion of the area of the hard exudates. By comparing the results with hand‐drawn ground truths, the authors obtained sensitivity and specificity of detecting hard exudates as 75.43 and 99.99%, respectively.
Semi‐supervised low‐rank representation graph for pattern recognition
Authors: Yang Shuyuan , Wang Xiuxiu , Wang Min , Han Yue , Jiao Licheng
Published: May 2013

In this study, the authors propose a new semi‐supervised low‐rank representation graph for pattern recognition. A collection of samples is jointly coded by the recently developed low‐rank representation (LRR), which better captures the global structure of data and implements more robust subspace segmentation from corrupted samples. By using the calculated LRR coefficients of both labelled and unlabelled samples as the graph weights, a low‐rank representation graph is established in a parameter‐free manner under the framework of semi‐supervised learning. Some experiments are taken on the benchmark database to investigate the performance of the proposed method and the results show that it is superior to other related semi‐supervised graphs.
Quality‐improved threshold visual secret sharing scheme by random grids
Authors: Lee Yao‐Sheng , Wang Bing‐Jian , Chen Tzung‐Her
Published: May 2013

Random grids (RGs)‐based visual secret sharing (VSS) has gained much attention in academia than before to avoid the potential drawbacks in visual cryptography‐based VSS. With its still being in infancy, a growing number of researches to RG‐based VSS demonstrate a great potential. Although there are some RG‐based schemes proposed in the past years for different applications, most of them can still be improved to achieve a better performance. This study proposes a new threshold RG‐based VSS scheme with better performance compared with the previous threshold RG‐based VSS scheme. The experimental results illustrate the feasibility; the better performance is theoretically analysed.
Hybrid approach for Farsi/Arabic text detection and localisation in video frames
Authors: Moradi Mohieddin , Mozaffari Saeed
Published: May 2013

Video text detection plays an important role in semantic‐based video analysis. In this study, a new Farsi/Arabic text detection and localisation approach is proposed. First, with the help of edge extraction, artificial corners are obtained and font size estimation is performed. Second, by combining discrete cosine transform coefficients, texture intensity picture is created. Afterwards, a new Local Binary Pattern (LBP) picture is introduced to describe the obtained texture pattern. The input image is then divided into macro blocks and some features are extracted from them and fed into Support Vector Machone (SVM) classifier to categorize them into text and non‐text groups. Finally, the candidate text blocks undergo project profile analysis and empirical rules for text localisation. Experimental results demonstrate that the proposed hybrid approach can be used as an automatic text detection system, which is robust to font size, font colour and background complexity.
Enhancing accuracy and sharpness of motion field with adaptive scheme and occlusion‐aware filter
Authors: Dung Nguyen Duc , Wook Jeon Jae
Published: May 2013

In this study, the authors propose an adaptive scheme to improve motion estimation of a variational model based on image features and flow quality measurements. Using image features, the authors introduce adaptive functions and inject them into the energy function to fine‐tune the estimation process. They propose a hybrid scheme to deal with large motions and improve the accuracy of the flow field. They introduce a trusted‐map based on constraints to measure flow quality. They use this map as a reference for the proposed occlusion‐aware filter. The proposed filter and hybrid scheme are integrated to correct the flow field iteratively, thus significantly improving the estimation results. The filter also enhances the flow field in occlusion areas. The authors experimental results demonstrate that their method provides sharp flow fields and significantly improved estimation accuracy.
Synthetic approaches to study transcriptional networks and noise in mammalian systems
Authors: Gregorio‐Godoy Paula , Míguez David G.
Published: May 2013

Synthetic biology aims to build new functional organisms and to rationally re‐design existing ones by applying the engineering principle of modularity. Apart from building new life forms to perform technical applications, the approach of synthetic biology is useful to dissect complex biological phenomena into simple and easy to understand synthetic modules. Synthetic gene networks have been successfully implemented in prokaryotes and lower eukaryotes, with recent approaches moving ahead towards the mammalian environment. However, synthetic circuits in higher eukaryotes present a more challenging scenario, since its reliability is compromised because of the strong stochastic nature of transcription. Here, the authors review recent approaches that take advantage of the noisy response of synthetic regulatory circuits to learn key features of the complex machinery that orchestrates transcription in higher eukaryotes. Understanding the causes and consequences of biological noise will allow us to design more reliable mammalian synthetic circuits with revolutionary medical applications.
The atmospheric chemical reaction of 4-tert-butylphenol initiated by OH radicals
Authors: Gong Chen , Sun Xiaomin , Zhang Chenxi
Published: May 2013

Environmental context 4-tert-Butylphenol, an environmental endocrine disruptor, can be taken in by humans and animals resulting in reproductive and developmental problems. We report a theoretical study on the degradation mechanism of 4-tert-butylphenol in the atmosphere, and calculate the atmospheric lifetime of this chemical. The data will help our understanding of the behaviour of 4-tert-butylphenol in the environment and thereby provide valuable information about its possible effect on human health. Abstract 4-tert-Butylphenol (TBP) is a typical environmental endocrine. In this paper, the OH-initiated degradation mechanism of TBP in the atmosphere is studied at the MPWB1K/6-31+G(d,p)//MPWB1K/6-311+G(3df,2p) level of computational theory. A profile of the potential energy surface is constructed and reaction pathways are analysed. The addition reactions of TBP with OH radicals are more important than abstraction reactions in the atmosphere. In subsequent reactions, O2 and NO may play an important role in the degradation process of TBP. The rate constants are calculated using the transition state theory and a canonical variational transition with small-curvature tunnelling correction. The Arrhenius equations of rate constants in the temperature range of 200–500K are fitted. The rate constant of the degradation of the TBP at 298.15K is 3.56×10–14cm3 molecule–1s–1 and the atmospheric lifetime is 10.8 months according to the pseudo-first-order kinetics.
Claudin-8 expression in Sertoli cells and putative spermatogonial stem cells in the bovine testis
Authors: McMillan Mary , Andronicos Nicholas , Davey Rhonda , Stockwell Sally , Hinch Geoff , Schmoelzl Sabine
Published: May 2013

Adhesion molecules are expressed by both adult and embryonic stem cells, with different classes of adhesion molecules involved in cell-membrane and intercellular contacts. In this study the expression of the adhesion molecule claudin-8 (CLDN8), a tight-junction protein, was investigated as a potential marker for undifferentiated spermatogonia in the bovine testis. We found that CLDN8 was expressed by both spermatogonia and a subset of Sertoli cells in the bovine testis. We also showed co-expression of GFRα1 in testis cells with CLDN8 and with Dolichos biflorus agglutinin–fluorescein isothiocyanate (DBA–FITC) staining. We observed co-enrichment of spermatogonia and CLDN8-expressing Sertoli cells in DBA–FITC-assisted magnetic-activated cell sorting (MACS), an observation supported by results from fluorescence-activated cell sorting analysis, which showed CLDN8-expressing cells were over-represented in the MACS-positive cell fraction, leading to the hypothesis that CLDN8 may play a role in the spermatogonial stem-cell niche.
ADAM-10 and -17 regulate endometriotic cell migration via concerted ligand and receptor shedding feedback on kinase signaling
Authors: Miller Miles A. , Meyer Aaron S. , Beste Michael T. , Lasisi Zainab , Reddy Sonika , Jeng Karen W. , Chen Chia-Hung , Han Jongyoon , Isaacson Keith , Griffith Linda G. , Lauffenburger Douglas A.
Published: May 2013

Significance

Regulated cell-surface proteolysis underpins processes of cellular migration in both physiological and pathological contexts. However, comprehending how multiple proteolytic events cohesively integrate to yield context-dependent cellular behavior remains a challenge. Here we present an experimental/computational paradigm for analyzing networks of protease activities that interface with signaling pathways to influence cellular migration in the invasive disease of endometriosis. We find that induced cellular migration is a quantitative consequence of positive feedback through ligand release and negative feedback through receptor shedding, which furthermore drives rapid resistance to kinase inhibitor treatment. Targeted clinical proteomics confirms dysregulated proteolysis in endometriosis.
Emergence of hierarchy in cost-driven growth of spatial networks
Authors: Louf Rémi , Jensen Pablo , Barthelemy Marc
Published: May 2013

One of the most important features of spatial networks—such as transportation networks, power grids, the Internet, and neural networks—is the existence of a cost associated with the length of links. Such a cost has a profound influence on the global structure of these networks, which usually display a hierarchical spatial organization. The link between local constraints and large-scale structure is not elucidated, however, and we introduce here a generic model for the growth of spatial networks based on the general concept of cost–benefit analysis. This model depends essentially on a single scale and produces a family of networks that range from the star graph to the minimum spanning tree and are characterized by a continuously varying exponent. We show that spatial hierarchy emerges naturally, with structures composed of various hubs controlling geographically separated service areas, and appears as a large-scale consequence of local cost–benefit considerations. Our model thus provides the basic building blocks for a better understanding of the evolution of spatial networks and their properties. We also find that, surprisingly, the average detour is minimal in the intermediate regime as a result of a large diversity in link lengths. Finally, we estimate the important parameters for various world railway networks and find that, remarkably, they all fall in this intermediate regime, suggesting that spatial hierarchy is a crucial feature for these systems and probably possesses an important evolutionary advantage.
Host and viral features of human dengue cases shape the population of infected and infectious
Aedes aegypti
mosquitoes
Authors: Nguyen Nguyet Minh , Thi Hue Kien Duong , Tuan Trung Vu , Quyen Nguyen Than Ha , Tran Chau N. B. , Vo Thi Long , Thi Dui Le , Nguyen Hoa Lan , Farrar Jeremy J. , Holmes Edward C. , Rabaa Maia A. , Bryant Juliet E. , Nguyen Truong Thanh , Nguyen Huong Thi Cam , Nguyen Lan Thi Hong , Pham Mai Phuong , Nguyen Hung The , Luong Tai Thi Hue , Wills Bridget , Nguyen Chau Van Vinh , Wolbers Marcel , Simmons Cameron P.
Published: May 2013

Dengue is the most prevalent arboviral disease of humans. The host and virus variables associated with dengue virus (DENV) transmission from symptomatic dengue cases (
n
= 208) to
Aedes aegypti
mosquitoes during 407 independent exposure events was defined. The 50% mosquito infectious dose for each of DENV-1–4 ranged from 6.29 to 7.52 log10 RNA copies/mL of plasma. Increasing day of illness, declining viremia, and rising antibody titers were independently associated with reduced risk of DENV transmission. High early DENV plasma viremia levels in patients were a marker of the duration of human infectiousness, and blood meals containing high concentrations of DENV were positively associated with the prevalence of infectious mosquitoes 14 d after blood feeding. Ambulatory dengue cases had lower viremia levels compared with hospitalized dengue cases but nonetheless at levels predicted to be infectious to mosquitoes. These data define serotype-specific viremia levels that vaccines or drugs must inhibit to prevent DENV transmission.