bluuebunny/crossref_metadata_2025 huggingface dataset:
BarR, an Lrp‐type transcription factor in Sulfolobus acidocaldarius, regulates an aminotransferase gene in a β‐alanine responsive manner
Authors: Liu Han , Orell Alvaro , Maes Dominique , van Wolferen Marleen , Ann‐Christin Lindås , Bernander Rolf , Albers Sonja‐Verena , Charlier Daniel , Peeters Eveline
Published: March 2014

In archaea, nothing is known about the β‐alanine degradation pathway or its regulation. In this work, we identify and characterize BarR, a novel Lrp‐like transcription factor and the first one that has a non‐proteinogenic amino acid ligand. BarR is conserved in Sulfolobus acidocaldarius and Sulfolobus tokodaii and is located in a divergent operon with a gene predicted to encode β‐alanine aminotransferase. Deletion of barR resulted in a reduced exponential growth rate in the presence of β‐alanine. Furthermore, qRT‐PCR and promoter activity assays demonstrated that BarR activates the expression of the adjacent aminotransferase gene, but only upon β‐alanine supplementation. In contrast, auto‐activation proved to be β‐alanine independent. Heterologously produced BarR is an octamer in solution and forms a single complex by interacting with multiple sites in the 170 bp long intergenic region separating the divergently transcribed genes. In vitro, DNA binding is specifically responsive to β‐alanine and site‐mutant analyses indicated that β‐alanine directly interacts with the ligand‐binding pocket. Altogether, this work contributes to the growing body of evidence that in archaea, Lrp‐like transcription factors have physiological roles that go beyond the regulation of α‐amino acid metabolism.
Cell‐wall invertases, key enzymes in the modulation of plant metabolism during defence responses
Authors: Proels Reinhard Korbinian , Hückelhoven Ralph
Published: March 2014

Most plant–pathogen interactions do not result in pathogenesis because of pre‐formed defensive plant barriers or pathogen‐triggered activation of effective plant immune responses. The mounting of defence reactions is accompanied by a profound modulation of plant metabolism. Common metabolic changes are the repression of photosynthesis, the increase in heterotrophic metabolism and the synthesis of secondary metabolites. This enhanced metabolic activity is accompanied by the reduced export of sucrose or enhanced import of hexoses at the site of infection, which is mediated by an induced activity of cell‐wall invertase (Cw‐Inv). Cw‐Inv cleaves sucrose, the major transport sugar in plants, irreversibly yielding glucose and fructose, which can be taken up by plant cells via hexose transporters. These hexose sugars not only function in metabolism, but also act as signalling molecules. The picture of Cw‐Inv regulation in plant–pathogen interactions has recently been broadened and is discussed in this review. An interesting emerging feature is the link between Cw‐Inv and the circadian clock and new modes of Cw‐Inv regulation at the post‐translational level.
Understanding evolution and the complexity of species interactions using orchids as a model system
Authors: Bronstein Judith L. , Armbruster W. Scott , Thompson John N.
Published: March 2014

See also the Commentary by Selosse
The buck in the milkweed: evidence of male–male interference among pollinaria on pollinators
Authors: Cocucci Andrea A. , Marino Salvador , Baranzelli Matías , Wiemer Ana P. , Sérsic Alicia
Published: March 2014

Direct physical confrontation among conspecifics for access to mates is a form of sexual selection well known among animals, but not thought to take place in plants. Consequently, no structures are known that can be considered as weapons that evolved under such confrontation. Pollinaria of milkweeds may physically compete for access to attachment points on the pollinators' body, and occasionally pollinaria may link onto pre‐existing pollinaria on a pollinator resulting in concatenation.

We hypothesized that concatenation may result in interference between proximal and distal pollinaria, and that features of nonconcatenating pollinaria might be attributed to prevention of concatenation. We tested this by analyzing pollen donation efficiency, experimental manipulation of the phenotype and the phylogenetic patterns of co‐occurrence of traits.

It is shown that concatenation was able to diminish the reproductive performance of proximal pollinaria, that horns on pollinaria prevented concatenation, and that horn acquisition was correlated with a loss of concatenation. The experimental removal of horns in species that did not concatenate caused reversion to concatenation.

The present work could be the first evidence of male physical struggles and of the acquisition of weapons related to these struggles, that are analogous to those known in animals.
Oil prices and stock market price in Nigeria
Authors: Nwosa Philip Ifeakachukwu
Published: March 2014

This paper examined the relationship between oil prices (international oil price and domestic oil price) and stock market price in Nigeria for the period spanning 1985:1 to 2010:4. The study utilised the Johansen's multivariate cointegration test and the vector error correction model (VECM). The Johansen's test showed that the variables are cointegrated, and the cointegration equation revealed that oil prices have significant relationship with stock market price in the long run. The VECM estimate only revealed a unidirectional causality from stock market price to international oil price in the long run. A unidirectional causality was also observed from domestic oil price to stock market price in the long run. The study recommended that policymakers, financial analyst and shareholders should into cognizance changes in international oil price and domestic oil price in their financial decisions given the significant impact of oil prices on stock market price in Nigeria.
Use of a Lateral Infraclavicular Puncture to Obtain Proximal Venous Access with Occluded Subclavian/Axillary Venous Systems for Cardiac Rhythm Devices
Authors: BERNSTEIN NEIL E. , AIZER ANTHONY , CHINITZ LARRY A.
Published: March 2014

Background

Venous occlusion is not uncommon and total venous obstruction with more proximal patency may occur in as many as 10% of previous implants. Many techniques are available to obtain ipsilateral access; however, most require special equipment or skills. We describe a technique of infraclavicular cannulation of the brachiocephalic vein ipsilateral to the occlusion that is safe and feasible for most implanters.

Methods

Fourteen patients with subclavian/axillary occlusions ipsilateral to the implanted device and requiring revision or upgrade of their system or venous occlusion with contraindication to implant on the contralateral side underwent lead addition/placement via a brachiocephalic approach. Following venography, an 18‐gauge needle was used to gain brachiocephalic access. The needle was initially positioned in a lateral infraclavicular location. The needle was then advanced under the clavicle in a horizontal plane and advanced toward the sternal notch under fluoroscopic guidance.

Results

Fourteen patients underwent an attempt at brachiocephalic access. Cannulation of the brachiocephalic was possible in all 14 and lead(s) were successfully implanted in all. There were no complications with the procedure, specifically no pneumothoraces. In follow‐up (mean 36 months, range 1–86 months), all implanted leads function well, with no evidence of lead failure or impedance changes.

Conclusion

A lateral infraclavicular approach is a safe and effective technique for obtaining brachiocephalic access when the subclavian/axillary vein is occluded. This technique is easy to learn and may be useful for implanters without the equipment or skills needed for lead extraction or microdissection or in cases where patients refuse these procedures.
Contrasting Effects of HMR1098 on Arrhythmogenicity in a Langendorff‐Perfused Phase‐2 Myocardial Infarction Rabbit Model
Authors: LEE HUI‐LING , LU CHENG‐HUI , CHANG PO‐CHENG , CHOU CHUNG‐CHUAN , WO HUNG‐TA , WEN MING‐SHIEN
Published: March 2014

Background

The stability of dynamic factors has been reported to play a role in the antiarrhythmic actions of adenosine triphosphate (ATP)‐sensitive potassium channel (KATP) opener in phase‐2 myocardial infarction (MI) hearts. In the situation of the downregulation of KATP, the effects of KATP blocker (HMR1098) on the dynamic factors and electrophysiological changes during phase‐2 MI remain unclear.

Methods

Dual voltage and intracellular Ca2+ (Cai) optical mapping was performed in nine Langendorff‐perfused hearts 4–5 hours after coronary artery ligation and five control hearts. Electrophysiology studies, including action potential duration (APD) restitution, conduction velocity (CV), inducibility of ventricular fibrillation (VF), VF dominant frequency, APD and Cai alternans, and Cai decay, were performed. The same protocol was repeated in the presence of HMR1098 (10 μm) after the baseline studies.

Results

HMR1098 significantly prolonged APD and effective refractory period to prevent sustained VF in five of nine MI hearts and two of five control hearts compared to none at baseline in both groups. On the other hand, HMR1098 steepened APD restitution slope to enhance spatially concordant alternans in both groups. In the phase‐2 MI group, HMR1098 steepened CV restitution slope and enhanced spatially discordant alternans (SDA), which might account for a decreased pacing threshold of VF induction during HMR1098 infusion in phase‐2 MI hearts.

Conclusions

In phase‐2 MI hearts, HMR1098 has contrasting effects on arrhythmogenesis, suppressing reentry and VF persistence but facilitating VF inducibility. The mechanism is the intensified induction of SDA because of the steepened APD and CV restitution slopes.
Universal Algorithm for Diagnosis of Biventricular Capture in Patients with Cardiac Resynchronization Therapy
Authors: JASTRZEBSKI MAREK , KUKLA PIOTR , FIJOREK KAMIL , CZARNECKA DANUTA
Published: March 2014

Background

An accurate and universal method for diagnosis of biventricular (BiV) capture using a standard 12‐lead electrocardiogram (ECG) would be useful for assessment of cardiac resynchronization therapy (CRT) patients. Our objective was to develop and validate such an ECG method for BiV capture diagnosis that would be independent of pacing lead positions—a major confounder that significantly influences the morphologies of paced QRS complexes.

Methods

On the basis of an evaluation of 789 ECGs of 443 patients with heart failure and various right ventricular (RV) and left ventricular (LV) lead positions, the following algorithm was constructed and validated. BiV capture was diagnosed if the QRS in lead I was predominantly negative and either V1 QRS was predominantly positive or V6 QRS was of negative onset and predominantly negative (step 1), or if QRS complex duration was <160 ms (step 2). All other ECGs were classified as loss of LV capture.

Results

The algorithm showed good accuracy (93%), sensitivity (97%), and specificity (90%) for detection of loss of LV capture. The performance of the algorithm did not differ among apical, midseptal, and outflow tract RV lead positions and various LV lead positions.

Conclusion

LV capture leaves diagnostic hallmarks in the fused BiV QRS related to different vectors of depolarization and more rapid depolarization of the ventricles. An accurate two‐step ECG algorithm for BiV capture diagnosis was developed and validated. This algorithm is universally applicable to all CRT patients, regardless of the positions of the pacing leads.
Molecular characterization and functional analysis of four β‐1,4‐endoglucanases from the root‐lesion nematode Pratylenchus vulnus
Authors: Fanelli E. , Troccoli A. , Picardi E. , Pousis C. , De Luca F.
Published: March 2014

This study reports on the isolation and characterization of four different endoglucanases in the root‐lesion nematode Pratylenchus vulnus. The gene structures of two of these, Pv‐eng‐1 and Pv‐eng‐2, were fully determined, and Pv‐eng‐3 and Pv‐eng‐5 were partially sequenced. Spatial expression of Pv‐eng‐1, Pv‐eng‐2 and Pv‐eng‐5 was examined by in situ hybridization. Pv‐eng‐1 and Pv‐eng‐2 transcripts were localized in the subventral oesophageal glands, whilst the Pv‐eng‐5 transcript was localized in the intestine. Real‐time RT‐PCR showed that three of the four endoglucanases had the highest transcriptional level in adult males and females, thus demonstrating that adults are also parasitic in P. vulnus. Mixed stages of P. vulnus were treated with double‐stranded RNA (dsRNA) of Pv‐eng‐1 in order to study the effect of gene silencing (RNAi). Silencing Pv‐eng‐1 by dsRNA targeting of the carbohydrate‐binding module (CBM) resulted in a significant reduction (88–98%) of the transcript level, suggesting that P. vulnus is susceptible to RNAi. Furthermore, silencing P. vulnus showed a reduction (54%) in nematode reproduction on carrot minidiscs over a 5 week period. These results suggest that silencing of Pv‐eng‐1 may result in reduction of the ability of the nematode to locate and invade roots and, therefore, to establish and reproduce.
Subsidizing Migration? Mexican Agricultural Policies and Migration to the United States
Authors: Cortina Jeronimo
Published: March 2014

Migration theories often ignore the role that states play in stimulating migration through public assistance policies. Using the case of Mexico, this article explores the role of the state as a migrant‐producing actor by examining the relationship between migration and social assistance policies in the form of monetary cash transfers. It argues that direct, unconditional cash transfers, like those provided by agricultural programs such as Procampo, rather than providing the incentives needed to retain individuals in their home country, may instead be providing the resources needed to migrate, particularly if the amount of the transfer is insufficient to spur investment. Instead of discouraging migration by enhancing economic opportunities and reducing poverty, such policies can actually make it easier and more appealing for its beneficiaries to migrate.
In vitro acetylcholinesterase inhibitory activity and the antioxidant properties of Aegle marmelos leaf extract: implications for the treatment of Alzheimer's disease
Authors: Asaduzzaman Md. , Uddin Md. Josim , Kader M.A. , Alam A.H.M.K. , Rahman Aziz Abdur , Rashid Mamunur , Kato Kiyoko , Tanaka Toshihisa , Takeda Masatoshi , Sadik Golam
Published: March 2014

Background

Alzheimer's disease (AD) is a progressive neurodegenerative disorder clinically characterized by loss of memory and cognition. The effective therapeutic options for AD are limited and thus there is a demand for new drugs. Aegle marmelos (Linn.) (A. marmelos) leaves have been used in traditional medicine to promote intellect and enhance memory. In this study, we evaluated A. marmelos for its acetylcholinesterase (AChE) inhibitory activity and antioxidant property in vitro in the treatment of AD.

Methods

A crude methanol extract and four fractions (petroleum ether, chloroform, ethyl acetate and aqueous) were prepared from the leaves of A. marmelos. The preparations were assessed for AChE inhibitory activity by the Ellman method, and their antioxidant properties were assessed by several assays: reducing power, scavenging of 1,1‐diphenyl‐2‐picrylhydrazyl free radical and hydroxyl radical, and inhibition of lipid peroxidation. Qualitative and quantitative analyses of endogenous substances in A. marmelos were performed by the standard phytochemical methods.

Results

Among the different extracts tested, the ethyl acetate fraction exhibited the highest inhibition of AChE activity. In the same way, ethyl acetate fraction showed the highest reducing activity and radical scavenging ability towards the 1,1‐diphenyl‐2‐picrylhydrazyl (half maximal inhibitory concentration = 3.84 μg/mL) and hydroxyl free radicals (half maximal inhibitory concentration = 5.68 μg/mL). The antiradical activity of the ethyl acetate fraction appeared to be similar to that of the reference standard butylated hydroxytoluene and catechin used in this study. In addition, the ethyl acetate fraction displayed higher inhibition of brain lipid peroxidation. Phytochemical screening of different extractives of A. marmelos showed the presence of phenols and flavonoids, alkaloid, saponin, glycoside, tannin and steroids. Quantitative analysis revealed higher contents of phenolics (58.79‐mg gallic acid equivalent/g dried extract) and flavonoids (375.73‐mg gallic acid equivalent/g dried extract) in the ethyl acetate fraction.

Conclusion

The results suggest that the ethyl acetate fraction of A. marmelos is a significant source of polyphenolic compounds with potential AChE inhibitory property and antioxidant activity and, thus, may be useful in the treatment of AD.
Episodic temporal structure modulates associative recognition processes: An MEG study
Authors: Tibon Roni , Vakil Eli , Levy Daniel A. , Goldstein Abraham
Published: March 2014

The formation of mnemonic associations can occur between items processed in temporal proximity. It has been proposed that such intertemporal associations are not unitizable, and may therefore be retrieved only via recollective processes. To examine this claim, we conducted a magnetoencephalograph study of recognition memory for items encoded and retrieved sequentially. Participants studied successively presented pairs of object pictures, and subsequently made old‐new item judgments under several retrieval conditions, differing in degree of reinstatement of associative information. Correct recognition was accompanied by an early event‐related field (ERF) component, seemingly corresponding to the FN400 event‐related potential component asserted to reflect familiarity; this retrieval success effect was not modulated by degree of associative binding. A later ERF component, corresponding to the late positive component asserted to reflect recollection, was modulated by degree of associative reinstatement. These results suggest that memory of intertemporal associations, which are not amenable to unitization, is accessed via recollection.
Psychometric properties of the error‐related negativity in children and adolescents
Authors: Meyer Alexandria , Bress Jennifer N. , Proudfit Greg Hajcak
Published: March 2014

Error processing is frequently examined using the error‐related negativity (ERN), a negative‐going event‐related potential occurring after the commission of an error at frontal‐central sites, and has been suggested as a neural biomarker that may be useful in characterizing trajectories of risk for anxiety. While theERNhas been shown to have excellent psychometric properties in adults, few studies have examined psychometric properties of theERNin children and adolescents. The current study examined the 2‐year test‐retest reliability of theERNin a sample of children and adolescents, and the convergent validity of theERNusing a flanker and go/no‐go task. Results suggest that theERNis both reliable and stable across 2 years and across tasks. However, results also indicate that the internal consistency obtained using the flanker task is greater than the internal consistency obtained using the go/no‐go task.
Early Warning for Currency Crises: What Is the Role of Financial Openness?
Authors: Frost Jon , Saiki Ayako
Published: March 2014

The paper explores whether financial openness—capital account openness and gross capital inflows—makes countries vulnerable to currency crises. A quarterly dataset on 46 advanced and emerging market economies (AEs and EMEs) during 1975Q1–2011Q4 is used, with the period after Q2 2007 used for out‐of‐sample testing. The key findings are: (1) capital account openness is associated with lower probability of currency crises, but less so for EMEs; (2) surges in gross capital flows are associated with increased risk of currency crises; and (3) the model performs well out‐of‐sample, confirming that early warning models are helpful in judging relative vulnerability.
Heterogeneity of treatment changes after psychodynamic therapy within a one year follow‐up: A replication study
Authors: Jensen Hans Henrik , Mortensen Erik Lykke , Lotz Martin
Published: March 2014

Naturalistic psychotherapy effect studies commonly report effect sizes for the total sample. However, a previous study of SCL‐90 Global Severity Index (GSI) improvement in a large outpatient sample used a cluster analytic strategy and reported clinical relevant outcome trajectories that could be grouped into early within‐treatment improvement, late improvement in the follow‐up period, and deteriorating patients with slight improvement that was lost at follow‐up. We explore GSI outcome trajectories and clinical significant change in a sample of 320 patients at a public psychiatric outpatient psychodynamic group therapy unit, the majority with anxiety, personality, and mood disorders. The study revealed large discharge and follow‐up effect sizes but more than one third of the patients were without measurable improvement. The major clusters described above were confirmed, and revealed unique clinical and socio‐demographic characteristics. Late improvers, as compared with early improvers, were characterized by anxiety symptoms and lack of network support after controlling for GSI at admission. Similarly, deteriorating patients had longer duration of illness and less favourable social characteristics compared with the other two groups. Early improving patients were less likely to have participated in short‐term groups, and only one third participated in additional treatment compared with more than 69% of the other patients. Severe and socially affected psychiatric patients, and patients with anxiety and agoraphobic symptoms may be less optimally treated in short‐term time limited psychodynamic groups. There is an obvious need for diversity of treatment offers, better integration of psycho‐social treatment components, and long‐term open ended treatment.
Individual differences in 10‐month‐olds' performance on the A‐not‐B task
Authors: Johansson Maria , Forssman Linda , Bohlin Gunilla
Published: March 2014

This study used the classical A‐not‐B task (Piaget, ) to explore individual differences in cognitive flexibility in 10‐month‐old infants by: (1) examining how differences in search performance during A trials relate to search performance during B trials; (2) studying the relation between temperamental dimensions and A‐not‐B performance; and (3) investigating differences in search performance between looking and reaching responses within the same task. Forty infants were tested on a fixed‐design‐version of the A‐not‐B task, not allowing for training or individual adjustment, but instead eliciting additional search behaviors than the common correct responses in A trials and perseverative errors in B trials. Infants were also rated by their parents on the temperamental scales Activity level and Attention span. The main findings were: (1) performance on A trials affected B trial performance, with infants being more correct on A trials having more incorrect and less ‘no search’ responses on B trials; (2) activity level, but not attention span, was related to performance on the A‐not‐B task, with infants performing better on A trials having a lower activity level; and (3) there were a few differences in performance with regard to modality, indicating that responding correctly by looking may be less cognitively demanding than doing so by reaching. This study demonstrated that 10‐month‐olds show a wide variation of search behaviors on this A‐not‐B task, resulting in individual differences in performance. These differences are suggested to reflect variation in temperamental activity level as well as maturity of short term/working memory, inhibition and cognitive flexibility.
Changes in 10‐year‐old children's body esteem: A time‐lag study between 2000 and 2010
Authors: Frisén Ann , Anneheden Linda
Published: March 2014

This time‐lag study examined if there has been any changes in body esteem over a 10‐year period for 10‐year old children in Gothenburg, Sweden. Two cohorts of children, one in year 2000 and one in 2010, answered the same questionnaire about body esteem. A total of 960 children, 515 girls and 445 boys, participated in the first wave in 2000 and a total of 342 children, 171 girls and 171 boys participated in the second wave in 2010. The results showed a general stability in levels of body esteem for both girls and boys over the past 10 years. The gender differences, with boys being more satisfied with their appearance and weight compared to girls also seems to be stable over the years. In addition, the results also showed a somewhat positive development among the overweight girls with enhanced body esteem for the overweight girls compared to the non‐overweight girls during the ten years studied. Unfortunately, the same pattern was not found for overweight boys. For them the discrepancy in body esteem compared to non‐overweight boys, with the overweight boys being more dissatisfied, found in 2000 remained in 2010.
Identification by sequence‐based high‐resolution typing of a novel HLA‐C allele, C*14:52, in a bone marrow donor
Authors: He J. , Dong L.‐N. , Wang W. , Zhu F.‐M. , Lv H.‐J.
Published: March 2014

HLA‐C*14:52 has one nucleotide difference from HLA‐C*14:02:01 at position 427G>C in exon 3.
Three novel HLA‐A*24 alleles identified in Chinese Han individuals
Authors: Zhu C. , Zhang H.‐W. , Zhang Y. , Nie X.‐M.
Published: March 2014

Three novel human leukocyte antigen alleles, A*24:224, A*24:225 and A*24:257, have been identified by sequence‐based typing.
SSX2‐4 expression in early‐stage non‐small cell lung cancer
Authors: Greve K. B. V. , Pøhl M. , Olsen K. E. , Nielsen O. , Ditzel H. J. , Gjerstorff M. F.
Published: March 2014

The expression of cancer/testis antigens SSX2, SSX3, and SSX4 in non‐small cell lung cancers (NSCLC) was examined, since they are considered promising targets for cancer immunotherapy due to their immunogenicity and testis‐restricted normal tissue expression. We characterized three SSX antibodies and performed immunohistochemical staining of 25 different normal tissues and 143 NSCLCs. The antibodies differed in binding to two distinctive splice variants of SSX2 that exhibited different subcellular staining patterns, suggesting that the two splice variants display different functions. SSX2‐4 expression was only detected in 5 of 143 early‐stage NSCLCs, which is rare compared to other cancer/testis antigens (e.g. MAGE‐A and GAGE). However, further studies are needed to determine whether SSX can be used as a prognostic or predictive biomarker in NSCLC.
Rationalizable Irrationalities of Choice
Authors: Dayan Peter
Published: March 2014

Although seemingly irrational choice abounds, the rules governing these mis‐steps that might provide hints about the factors limiting normative behavior are unclear. We consider three experimental tasks, which probe different aspects of non‐normative choice under uncertainty. We argue for systematic statistical, algorithmic, and implementational sources of irrationality, including incomplete evaluation of long‐run future utilities, Pavlovian actions, and habits, together with computational and statistical noise and uncertainty. We suggest structural and functional adaptations that minimize their maladaptive effects.
Methods for Separation of Copper Oxide Nanoparticles From Colloidal Suspension in Dodecane
Authors: Sheikh Mohammed H. , Sharif Muhammad A. R.
Published: March 2014

Phase change materials (PCM) are used in many energy storage applications. Energy is stored (latent heat of fusion) by melting the PCM and is released during resolidification. Dispersing highly conductive nanoparticles into the PCM enhances the effective thermal conductivity of the PCM, which in turn significantly improves the energy storage capability of the PCM. The resulting colloidal mixture with the nanoparticles in suspension is referred to as nanostructure enhanced phase change materials (NEPCM). A commonly used PCM for energy storage application is the family of paraffin (CnH2n+2). Mixing copper oxide (CuO) nanoparticles in the paraffin produces an effective and highly efficient NEPCM for energy storage. However, after long term application cycles, the efficiency of the NEPCM may deteriorate and it may need replacement with fresh supply. Disposal of the used NEPCM containing the nanoparticles is a matter of concern. Used NEPCM containing nanoparticles cannot be discarded directly into the environment because of various short term health hazards for humans and all living beings and unidentified long term environmental and health hazards due to nanoparticles. This problem will be considerable when widespread use of NEPCM will be practiced. It is thus important to develop technologies to separate the nanoparticles before the disposal of the NEPCM. The primary objective of this research work is to develop methods for the separation and reclamation of the nanoparticles from the NEPCM before its disposal. The goal is to find, design, test, and evaluate separation methods which are simple, safe, and economical. The specific NEPCM considered in this study is a colloidal mixture of dodecane (C12H26) and CuO nanoparticles (1–5% mass fraction and 5–15 nm size distribution). The nanoparticles are coated with a surfactant or stabilizing ligands for suspension stability in the mixture for a long period of time. Various methods for separating the nanoparticles from the NEPCM are explored. The identified methods include: (i) distillation under atmospheric and reduced pressure, (ii) mixing with alcohol mixture solvent, and (iii) high speed centrifugation. These different nanoparticle separation methods have been pursued and tested, and the results are analyzed and presented in this article.
A Novel Fingertip Design for Slip Detection Under Dynamic Load Conditions
Authors: Nacy Somer M. , Tawfik Mauwafak A. , Baqer Ihsan A.
Published: March 2014

This paper presents a novel design of a fingertip mechanism for detecting the slippage of the grasped object under two different types of dynamic load. This design is to be used with an underactuated triple finger artificial hand based on pulleys-tendon mechanism and the grasped object is designed in a prism shape with three DC motors with unbalance rotating mass to generate the excitation in the object, these motors are distributed symmetrically on the faces of the object. This prism shaped object is connected to a rope type pulling system to force the object to slip under quasi-static load condition. The mathematical modeling has been derived for the proposed design to generate the signal of contact force components ratio through using the conventional sensors signals with the aid of matlab–simulink software. The experimental results are discussed in comparison with the physical aspect of slippage phenomenon and they show good agreement with the physical definition of the slippage phenomenon.
From Parasitism to Mutualism: Unexpected Interactions Between a Cuckoo and Its Host
Authors: Canestrari Daniela , Bolopo Diana , Turlings Ted C. J. , Röder Gregory , Marcos José M. , Baglione Vittorio
Published: March 2014

Predation Favors Parasitism

Parasitism in birds often results in ejection or starvation of the host's nestlings. Consequently, many host bird species have evolved protective behavior such as mobbing and parasite egg rejection. Curiously, some host species show no parasite avoidance behaviors; for example, the crow
Corvus corone corone
tolerates cuckoo chicks among its own brood. In a long-term study,

Canestrari
et al.

(p.
1350
) found that crow nests containing a cuckoo chick had lower rates of predation because the parasite's chicks secrete a noxious repellent substance. Overall, in years of high predation pressure, the presence of cuckoos improves the crow's breeding success, but when there are fewer predators around, parasitism reduces crow fitness.
Testing the Limits of Accretion
Authors: King Andrew
Published: March 2014

Observations reveal a greater influence of rapidly accreting black holes on their host galaxy than expected.

[Also see Report by

Soria
et al.

]
Wonders from Cambridge Collections
Discoveries
Art, Science and Exploration from the University of Cambridge Museums

Nicholas Thomas and Martin Caiger-Smith, with Lydia Hamlett, curators

Two Temple Place, London. Through 27 April 2014. www.twotempleplace.org/exhibitions/current-exhibition; www.fitzmuseum.cam.ac.uk/discoveries
Authors: Dixon Deborah
Published: March 2014

Juxtaposing objects from eight Cambridge University museums, the exhibition illustrates links among art, science, and exploration.
RIPK3 Takes Another Deadly Turn
Authors: Zhang Jianke , Chan Francis Ka-Ming
Published: March 2014

Blocking an enzyme involved in necroptosis may prove toxic by promoting another form of cell death.

[Also see Report by

Newton
et al.

]
The Vigilante
Authors: Bhattacharjee Yudhijit
Published: March 2014

When the ENCODE Project declared that there is no such thing as junk DNA, Dan Graur counterattacked. But does he go too far?
Genetic Diversity and Antimicrobial Susceptibility of Campylobacter jejuni Isolates Associated with Sheep Abortion in the United States and Great Britain
Authors: Wu Zuowei , Sippy Rachel , Sahin Orhan , Plummer Paul , Vidal Ana , Newell Diane , Zhang Qijing
Published: March 2014

Campylobacterinfection is a leading cause of ovine abortion worldwide. Historically, genetically diverseCampylobacter fetusandCampylobacter jejunistrains have been implicated in such infections, but since 2003 a highly pathogenic, tetracycline-resistantC. jejuniclone (named SA) has become the predominant cause of sheep abortions in the United States. Whether clone SA was present in earlier U.S. abortion isolates (before 2000) and is associated with sheep abortions outside the United States are unknown. Here, we analyzed 54C. jejuniisolates collected from U.S. sheep abortions at different time periods and compared them with 42C. jejuniisolates associated with sheep abortion during 2002 to 2008 in Great Britain, using multilocus sequence typing (MLST), pulsed-field gel electrophoresis (PFGE), and array-based comparative genomic hybridization (CGH). Although clone SA (ST-8) was present in the early U.S. isolates, it was not as tetracycline resistant (19% versus 100%) or predominant (66% versus 91%) as it was in the late U.S isolates. In contrast,C. jejuniisolates from Great Britain were genetically diverse, comprising 19 STs and lacking ST-8. PFGE and CGH analyses of representative strains further confirmed the population structure of the abortion isolates. Notably, the Great Britain isolates were essentially susceptible to most tested antibiotics, including tetracycline, while the late U.S. isolates were universally resistant to this antibiotic, which could be explained by the common use of tetracyclines for control of sheep abortions in the United States but not in Great Britain. These results suggest that the dominance of clone SA in sheep abortions is unique to the United States, and the use of tetracyclines may have facilitated selection of this highly pathogenic clone.
Fosfomycin Susceptibility in Carbapenem-Resistant Enterobacteriaceae from Germany
Authors: Kaase Martin , Szabados Florian , Anders Agnes , Gatermann Sören G.
Published: March 2014

Due to the increase in multidrug-resistant
Enterobacteriaceae
, the interest in older antimicrobial agents, like fosfomycin, has increased. In this study, we used agar dilution for testing susceptibilities to fosfomycin in a collection of 107 carbapenem-nonsusceptible
Enterobacteriaceae
isolates, of which 80 produced various types of carbapenemases, including KPC, VIM, NDM, and OXA-48. Overall, 78% of the strains had fosfomycin MICs of ≤32 mg/liter and were thus considered to be susceptible according to the current EUCAST breakpoint. The MIC
50
and MIC
90
were 8 mg/liter and 512 mg/liter, respectively.
Escherichia coli
strains had significantly lower fosfomycin MICs than the
Klebsiella pneumoniae
and
Enterobacter cloacae
strains. Furthermore, comparisons of the susceptibility testing methods, like Etest and disk diffusion, were performed against agar dilution as the reference method. Essential agreement between Etest and agar dilution was 78.9%, and categorical agreement between the two methods was 92.5%, with 20% very major errors and 2.6% major errors. Disk diffusion was studied with 50-μg and 200-μg fosfomycin disks, but no inhibition zone breakpoint that reduced very major and major errors to an acceptable level was found. Etest and disk diffusion showed poor agreement with fosfomycin agar dilution.
Comparison of Microscopy, Nested-PCR, and Real-Time-PCR Assays Using High-Throughput Screening of Pooled Samples for Diagnosis of Malaria in Asymptomatic Carriers from Areas of Endemicity in Myanmar
Authors: Wang Bo , Han Soe-Soe , Cho Cho , Han Jin-Hee , Cheng Yang , Lee Seong-Kyun , Galappaththy Gawrie N. L , Thimasarn Krongthong , Soe Myat Thu , Oo Htet Wai , Kyaw Myat Phone , Han Eun-Taek
Published: March 2014

Asymptomatic infection is an important obstacle for controlling disease in countries where malaria is endemic. Because asymptomatic carriers do not seek treatment for their infections, they can have high levels of gametocytes and constitute a reservoir available for new infection. We employed a sample pooling/PCR-based molecular detection strategy for screening malaria infection in residents from areas of Myanmar where malaria is endemic. Blood samples (
n
= 1,552) were collected from residents in three areas of malaria endemicity (Kayin State, Bago, and Tanintharyi regions) of Myanmar. Two nested PCR and real-time PCR assays showed that asymptomatic infection was detected in about 1.0% to 9.4% of residents from the surveyed areas. The sensitivities of the two nested PCR and real-time PCR techniques were higher than that of microscopy examination (sensitivity, 100% versus 26.4%; kappa values, 0.2 to 0.5). Among the three regions, parasite-positive samples were highly detected in subjects from the Bago and Tanintharyi regions. Active surveillance of residents from regions of intense malaria transmission would reduce the risk of morbidity and mitigate transmission to the population in these areas of endemicity. Our data demonstrate that PCR-based molecular techniques are more efficient than microscopy for nationwide surveillance of malaria in countries where malaria is endemic.
An Evaluation of Phylogenetic Methods for Reconstructing Transmitted HIV Variants using Longitudinal Clonal HIV Sequence Data
Authors: McCloskey Rosemary M. , Liang Richard H. , Harrigan P. Richard , Brumme Zabrina L. , Poon Art F. Y.
Published: March 2014

A population of human immunodeficiency virus (HIV) within a host often descends from a single transmitted/founder virus. The high mutation rate of HIV, coupled with long delays between infection and diagnosis, make isolating and characterizing this strain a challenge. In theory, ancestral reconstruction could be used to recover this strain from sequences sampled in chronic infection; however, the accuracy of phylogenetic techniques in this context is unknown. To evaluate the accuracy of these methods, we applied ancestral reconstruction to a large panel of published longitudinal clonal and/or single-genome-amplification HIV sequence data sets with at least one intrapatient sequence set sampled within 6 months of infection or seroconversion (n= 19,486 sequences, median [interquartile range] = 49 [20 to 86] sequences/set). The consensus of the earliest sequences was used as the best possible estimate of the transmitted/founder. These sequences were compared to ancestral reconstructions from sequences sampled at later time points using both phylogenetic and phylogeny-naive methods. Overall, phylogenetic methods conferred a 16% improvement in reproducing the consensus of early sequences, compared to phylogeny-naive methods. This relative advantage increased with intrapatient sequence diversity (P< 10−5) and the time elapsed between the earliest and subsequent samples (P< 10−5). However, neither approach performed well for reconstructing ancestral indel variation, especially within indel-rich regions of the HIV genome. Although further improvements are needed, our results indicate that phylogenetic methods for ancestral reconstruction significantly outperform phylogeny-naive alternatives, and we identify experimental conditions and study designs that can enhance accuracy of transmitted/founder virus reconstruction.

IMPORTANCEWhen HIV is transmitted into a new host, most of the viruses fail to infect host cells. Consequently, an HIV infection tends to be descended from a single “founder” virus. A priority target for the vaccine research, these transmitted/founder viruses are difficult to isolate since newly infected individuals are often unaware of their status for months or years, by which time the virus population has evolved substantially. Here, we report on the potential use of evolutionary methods to reconstruct the genetic sequence of the transmitted/founder virus from its descendants at later stages of an infection. These methods can recover this ancestral sequence with an overall error rate of about 2.3%—about 15% more information than if we had ignored the evolutionary relationships among viruses. Although there is no substitute for sampling infections at earlier points in time, these methods can provide useful information about the genetic makeup of transmitted/founder HIV.
The Measles Virus Hemagglutinin Stalk: Structures and Functions of the Central Fusion Activation and Membrane-Proximal Segments
Authors: Navaratnarajah Chanakha K. , Kumar Swati , Generous Alex , Apte-Sengupta Swapna , Mateo Mathieu , Cattaneo Roberto
Published: March 2014

The measles virus (MeV) membrane fusion apparatus consists of a fusion protein trimer and an attachment protein tetramer. To trigger membrane fusion, the heads of the MeV attachment protein, hemagglutinin (H), bind cellular receptors while the 96-residue-long H stalk transmits the triggering signal. Structural and functional studies of the triggering mechanism of other paramyxoviruses suggest that receptor binding to their hemagglutinin-neuraminidase (HN) results in signal transmission through the central segments of their stalks. To gain insight into H-stalk structure and function, we individually replaced its residues with cysteine. We then assessed how stable the mutant proteins are, how efficiently they can be cross-linked by disulfide bonds, whether cross-linking results in loss of function, and, in this case, whether disulfide bond reduction restores function. While many residues in the central segment of the stalk and in the spacer segment above it can be efficiently cross-linked by engineered disulfide bonds, we report here that residues 59 to 79 cannot, suggesting that the 20 membrane-proximal residues are not engaged in a tetrameric structure. Rescue-of-function studies by disulfide bond reduction resulted in the redefinition and extension of the central fusion-activation segment as covering residues 84 to 117. In particular, we identified four residues located between positions 92 and 99, the function of which cannot be restored by disulfide bond reduction after cysteine mutagenesis. These mutant H proteins reached the cell surface as complex oligomers but could not trigger membrane fusion. We discuss these observations in the context of the stalk exposure model of membrane fusion triggering by paramyxoviruses.

IMPORTANCE
Measles virus, while being targeted for eradication, still causes significant morbidity and mortality. Here, we seek to understand how it enters cells by membrane fusion. Two viral integral membrane glycoproteins (hemagglutinin tetramers and fusion protein trimers) mediate the concerted receptor recognition and membrane fusion processes. Since previous studies have suggested that the hemagglutinin stalk transmits the triggering signal to the fusion protein trimer, we completed an analysis of its structure and function by systematic Cys mutagenesis. We report that while certain residues of the central stalk segment confer specificity to the interaction with the fusion protein trimer, others are necessary to allow folding of the H-oligomer in a standard conformation conducive to fusion triggering, and still other residues sustain the conformational change that transmits the fusion-triggering signal.
Primary colonic signet ring cell carcinoma in a young patient
Authors: Prabhu Raghunath , Kumar Neha , Krishna Sunil , Shenoy Rajgopal
Published: March 2014

A 28-year-old woman presented with colicky abdominal pain for 3 months. Pain was associated with episodes of vomiting, abdominal distension and constipation. She also had loss of weight for this duration. General physical examination was unremarkable and the abdomen was soft, with no palpable organomegaly. A CT of the abdomen showed small bowel and ascending colon dilation with multiple air fluid levels. There was also a short segment of circumferential bowel wall thickening and luminal narrowing in the hepatic flexure with sudden transition of bowel diameter. She underwent a right hemicolectomy after necessary preoperative investigations. Histopathology revealed signet ring cell carcinoma (SRCC). This case highlights the importance of detecting such a lesion in a young, otherwise fit woman. The challenge lies in early diagnosis and awareness of general practitioners about this aggressive form of colonic tumours.
Endodontic retreatment of a mandibular first molar with five root canal systems: an important clinical lesson
Authors: Hasan Muhammad , Umer Fahad
Published: March 2014

The objective of root canal treatment is to perform complete debridement of the root canals and subsequent obturation to facilitate healing of periapical pathosis. However, this process becomes complicated with the presence of additional root canal systems. The purpose of the present article is to report successful non-surgical retreatment of a mandibular first molar with five canals. This case report discusses the clinical management of a previously root filled mandibular firstmolar with two missed canal systems; distolingual and an additional mesial canal known as the middle mesial canal. The post-treatment radiographs show successful obturation to length in all canals. The middle mesial canal was found to be associated with mesiolingual canal and categorised as confluent. The configuration of canals in the mesial root was type XV, based on the classification given by Sert and Bayirli. This case report highlights the importance of knowledge and its application in the management of abnormal anatomic variants which play a crucial role in the success of endodontic retreatment.
Asymptomatic posterior mediastinal teratoma diagnosed incidentally
Authors: Jaiswal Riddhi , Rani Poonam , Devenraj Vijayant
Published: March 2014

We present a young patient with occasional chest pain and an incidentally found posterior mediastinal mass on radiology which was confirmed as mature teratoma on histopathology. The gross specimen received in the department of pathology was globular measuring 9.0×7.0×5.5 cm and varying in consistency from soft cystic to firm. Cut surface showed numerous hair entangled in pultaceous material. Representative sections were taken and stained with H&E stain. Histopathology revealed haphazardly distributed mature derivatives of all the three germ layers comprising of epidermis, pilo sebaceous units, nerve bundles (ectodermal), cartilage, bone, salivary gland clusters, blood vessels, muscle bundles, fibrous tissue infiltrated by foreign body giant cells, lymphoid follicles (mesodermal) and pseudostratified columnar epithelium (mesodermal), thus establishing the diagnosis of mature teratoma.