bluuebunny/crossref_metadata_2025 huggingface dataset:
Surface and size effects on phase diagrams of ferroelectric nanocylinders
Authors: Zheng Yue , Lin S. P. , Wang Biao
Published: August 2011

Size-temperature phase diagrams of ferroelectric nanocylinder have been investigated. Taking into account existence of the depolarization field, surface and size effects, an eighth-order polynomial of the modified thermodynamic model has been established. Our results show that the phase diagrams obviously vary with ratio of the length and radius, and can be adjusted by the mechanical loads especially.
Stretchability of encapsulated electronics
Authors: Wu J. , Liu Z. J. , Song J. , Huang Y. , Hwang K.-C. , Zhang Y. W. , Rogers J. A.
Published: August 2011

Stretchable and flexible electronics offer the performance of conventional wafer-based systems but can be stretched like a rubber band, twisted like a rope, and bent over a pencil. Such a technology offers new application opportunities, in areas of surgical and diagnostic implements that naturally integrate with the human body to provide advanced capabilities, to curvilinear devices such as hemispherical “eyeball” cameras. In practice, stretchable and flexible electronic systems require encapsulation layers to provide mechanical and environmental protection. This paper establishes a simple, analytical model for the optimal design of encapsulation.
Optical properties of boron nitride nanoribbons: Excitonic effects
Authors: Wang Shudong , Chen Qian , Wang Jinlan
Published: August 2011

The optical properties of zigzag and armchair boron nitride nanoribbons (BNNRs) are investigated via a GW-Bethe-Salpeter equation approach. The reduced dimensionality and large band gaps of the BNNRs significantly enhance the exciton binding energies up to several eV. Many-body effects dramatically reshape the absorption spectra and excitonic peaks dominate the spectra. Moreover, the absorption spectra of zigzag BNNRs distinctly differ from those of armchair BNNRs, which can be as a signature to distinguish these two kinds of BNNRs experimentally. Dark excitons, stemming from dipole-forbidden transition, are also observed in BNNRs, which might greatly influence the luminescence yield of the system.
Enhancement in emission efficiency of diamond deep-ultraviolet light emitting diode
Authors: Makino Toshiharu , Yoshino Kiyoshi , Sakai Norihiro , Uchida Kouji , Koizumi Satoshi , Kato Hiromitsu , Takeuchi Daisuke , Ogura Masahiko , Oyama Kazuhiro , Matsumoto Tsubasa , Okushi Hideyo , Yamasaki Satoshi
Published: August 2011

We demonstrate high-efficiency excitonic emission with deep-ultraviolet (DUV) light of 235 nm at room temperature for a (111)-oriented diamond p-i-n junction light-emitting diode (LED) by introducing a thick i-layer. Significant enhancement in excitonic emission efficiency of over 500 times was observed for a diamond LED by increasing the i-layer thickness from 0.1 to 14 μm. Maximum output power and external quantum efficiency of excitonic emission for the LED without any specific device structure were 0.1 mW and 0.006%, respectively, under pulsed-current injection. We also demonstrate the sterilization of Escherichia coli by irradiation with DUV light from the diamond LED.
White light emission from CdTe quantum dots decorated n-ZnO nanorods/p-GaN light-emitting diodes
Authors: Dai J. , Ji Y. , Xu C. X. , Sun X. W. , Leck K. S. , Ju Z. G.
Published: August 2011

ZnO-based heterostructured light-emitting diode was fabricated by hydrothermally growing ZnO nanorods on p-type GaN substrate. Blue-violet electroluminescence was observed from the ZnO/GaN diode. The color-tunable CdTe quantum dots (QDs) samples with photoluminescence emission peaks ranging from 550 nm to 660 nm were synthesized. We fabricated two hybrid light-emitting diodes by decorating different CdTe QDs on the ZnO nanorods/GaN diodes, the white light emission was effectively observed from such devices.
An Observation Of Cat Predation Upon An Eastern Blossom Bat Syconycteris Australis
Authors: Phillips S , Coburn D , James R
Published: August 2011

WITH a body weight of 15 - 19 g and a mean headbody
length of just over 60 mm (Churchill 1998), the
eastern blossom bat Syconycteris australis is one of
the smallest members of the sub-order
Megachiroptera. Within Australia S. australis is
restricted in distribution to the east coast from Cape
York in Queensland to near Forster on the mid-north
coast of New South Wales (NSW) (Law 1994a).
Habitat requirements include both rainforest and/or
wet sclerophyll forest for roosting purposes and
proximal areas of heathland for foraging (Law 1993).
The species survives on a diet of nectar and pollen
and is heavily dependent upon Banksia integrifolia
inflorescences during the winter months (Law 1994b,
1996; Coburn 1995). Blossom bats are generally
regarded as solitary and exhibit strong fidelity to their
feeding areas (Law 1993), although movements of up
to 30 km have been reported (Law 1996).
Observations On The Reproductive Biology Of Myoictis Albopunctatus And Dasyurus Spartacus, Dasyurid Wallacei, Neophascogale Lorentzi, Dasyurus Marsupials Endemic To New Guinea.
Authors: Woolley PA
Published: August 2011

FIELD and laboratory observations on the
reproductive biology of seven species of dasyurid
marsupials endemic to New Guinea (viz.
?Antechinus? habbema, ?Antechinus? melanurus,
?Antechinus? naso, Murexia longicaudata, Murexia
rothschildi, Myoictis melas and Phascolosorex
dorsalis) have been recorded by Woolley (in press).
Here, less detailed observations on another four,
previously unstudied, species (Myoictis wallacei,
Neophascogale lorentzi, Dasyurus albopunctatus and
Dasyurus spartacus) are presented to provide
information on some aspects of reproduction in each
species. Only a small number of individuals of each
species were trapped, or collected by other means,
and maintained in captivity (Table 1). The methods
used for trapping and maintenance can be found in
Woolley (1993), and for the observations made on
the animals, Woolley (in press). Captive breeding
could not be attempted because only one sex of each
species was maintained. The limited reproductive
data obtained from individuals at the time of capture,
and from captive animals, is summarised for males in
Table 2 and Fig. 1, and for females in Table 3.
A Significant Range Extension Of The Purple-Necked Petrogale Purpureicollis Rockwallaby
Authors: Johnson PM , Eldridge MDB , Kiernan V , Cupitt RJ
Published: August 2011

IN 1982, the Queensland subspecies of the blackfooted
rock-wallaby Petrogale lateralis purpureicollis
was reported to occur around Mt Isa and south to
around Dajarra (Briscoe et al. 1982). During 1991, the
known range of this taxon was extended 300 km to
the north-west when an adult female P. l.
purpureicollis was collected from ?Ridgepole
Waterhole? in the Musselbrook Resource Reserve
near Lawn Hill National Park (Eldridge et al. 1993). In
1994 the range was further extended when P. l.
purpureicollis was recorded from the Constance
Ranges and the upper reaches of Stockyard and
Elizabeth Creeks; around the town of Cloncurry and
the following distances from the town: 85 km north
west; 60 and 87 km west; 4, 23, 28 and 35 km south
and 15 km east (Bell et al. 1995). Approaches by the
Cannington Mining operation to the southwest of
McKinley in October 1999 to confirm the presence
of rock-wallabies on nearby Glenholme Station
established the presence of P. l. purpureicollis; a 75
km range extension to the south-east.
ATP-activated P2X2 current in mouse spermatozoa
Authors: Navarro Betsy , Miki Kiyoshi , Clapham David E.
Published: August 2011

Sperm cells acquire hyperactivated motility as they ascend the female reproductive tract, which enables them to overcome barriers and penetrate the cumulus and zona pellucida surrounding the egg. This enhanced motility requires Ca
2+
entry via cation channel of sperm (CatSper) Ca
2+
-selective ion channels in the sperm tail. Ca
2+
entry via CatSper is enhanced by the membrane hyperpolarization mediated by Slo3, a K
+
channel also present in the sperm tail. To date, no transmitter-mediated currents have been reported in sperm and no currents have been detected in the head or midpiece of mature spermatozoa. We screened a number of neurotransmitters and biomolecules to examine their ability to induce ion channel currents in the whole spermatozoa. Surprisingly, we find that none of the previously reported neurotransmitter receptors detected by antibodies alone are functional in mouse spermatozoa. Instead, we find that mouse spermatozoa have a cation-nonselective current in the midpiece of spermatozoa that is activated by external ATP, consistent with an ATP-mediated increase in intracellular Ca
2+
as previously reported. The ATP-dependent current is not detected in mice lacking the P2X2 receptor gene (
P2rx2
−/−
). Furthermore, the slowly desensitizing and strongly outwardly rectifying ATP-gated current has the biophysical and pharmacological properties that mimic heterologously expressed mouse P2X2. We conclude that the ATP-induced current on mouse spermatozoa is mediated by the P2X2 purinergic receptor/channel. Despite the loss of ATP-gated current,
P2rx2
−/−
spermatozoa have normal progressive motility, hyperactivated motility, and acrosome reactions. However, fertility of
P2rx2
−/−
males declines with frequent mating over days, suggesting that P2X2 receptor adds a selection advantage under these conditions.
Rotational temperatures of N2(C,0) and OH(A,0) as gas temperature estimates in the middle pressure Ar/O2 discharge
Authors: Raud J , Laan M , Jõgi I
Published: August 2011

Radiative transitions N2(C–B,0–0) and OH(A–X,0–0) were used in order to estimate rotational temperatures of N2(C,0) and OH(A,0) in the middle pressure Ar/0.5% O2 RF discharge. N2(C,0) and OH(A,0) rotational temperature dependence on power density was determined and quenching/rotational relaxation frequencies of N2(C,0) and OH(A,0) were calculated. It was found that under our conditions rotational temperature of OH(A,0) can be used for estimation of gas temperature while N2(C,0) rotational temperature overestimates the gas temperature.
Magnetic field approaches in dc thermal plasma modelling
Authors: Freton P , Gonzalez J J , Masquère M , Reichert Frank
Published: August 2011

The self-induced magnetic field has an important role in thermal plasma configurations generated by electric arcs as it generates velocity through Lorentz forces. In the models a good representation of the magnetic field is thus necessary. Several approaches exist to calculate the self-induced magnetic field such as the Maxwell–Ampere formulation, the vector potential approach combined with different kinds of boundary conditions or the Biot & Savart (B&S) formulation. The calculation of the self-induced magnetic field is alone a difficult problem and only few papers of the thermal plasma community speak on this subject. In this study different approaches with different boundary conditions are applied on two geometries to compare the methods and their limitations. The calculation time is also one of the criteria for the choice of the method and a compromise must be found between method precision and computation time. The study shows the importance of the current carrying path representation in the electrode on the deduced magnetic field. The best compromise consists of using the B&S formulation on the walls and/or edges of the calculation domain to determine the boundary conditions and to solve the vector potential in a 2D system. This approach provides results identical to those obtained using the B&S formulation over the entire domain but with a considerable decrease in calculation time.
Sputter yield amplification by tungsten doping of Al2O3 employing reactive serial co-sputtering: process characteristics and resulting film properties
Authors: Austgen M , Koehl D , Zalden P , Kubart T , Nyberg T , Pflug A , Siemers M , Berg S , Wuttig M
Published: August 2011

The deposition rate of reactively sputtered Al2O3 coatings is demonstrated to increase by 80% upon tungsten doping of the used aluminium target. This effect is based on the recoil of the sputtering species at implanted dopants below the target surface and is termed sputter yield amplification. For the investigation of this effect, a novel type of magnetron sputter deposition system is employed that facilitates serial co-sputtering. In this technique doping of the elementary target is enabled by a dynamic sputtering process from an auxiliary cathode. In our case, the rotating aluminium target is dynamically coated with tungsten from this auxiliary cathode. Since the primary target rotates, the auxiliary cathode is placed in series with the primary erosion zone. The deposition rate of Al2O3 can be considerably increased in this process already for very low concentrations of approximately 1% of tungsten in the resulting film. A characterization of the dynamics of reactive sputtering as a function of target rotation speed is performed.
Non-cyclic algebras with 𝑛-central elements
Authors: Matzri Eliyah , Rowen Louis , Vishne Uzi
Published: August 2011

We construct, for any prime

p
p

, a non-cyclic central simple algebra of degree

p
2

p^2

with

p
2

p^2

-central elements. This construction answers a problem of Peter Roquette.
A metric between quasi-isometric trees
Authors: Martínez-Pérez Álvaro
Published: August 2011

It is known that PQ-symmetric maps on the boundary characterize the quasi-isometry type of visual hyperbolic spaces, in particular, of geodesically complete

R

\mathbb {R}

-trees. We define a map on pairs of PQ-symmetric ultrametric spaces which characterizes the branching of the space. We also show that when the ultrametric spaces are the corresponding end spaces, this map defines a metric between rooted geodesically complete simplicial trees with minimal vertex degree 3 in the same quasi-isometry class. Moreover, this metric measures how far the trees are from being rooted isometric.
Cross-talk between distinct nuclear import pathways enables efficient nuclear import of E47 in conjunction with its partner transcription factors
Authors: Mehmood Rashid , Yasuhara Noriko , Fukumoto Masahiro , Oe Souichi , Tachibana Taro , Yoneda Yoshihiro
Published: August 2011

Nuclear import of karyophilic proteins is carried out by a variety of mechanisms. We previously showed that two basic helix-loop-helix proteins, NeuroD1 and E47, synergistically affect each other's nuclear import. In this study, we dissected the molecular pathways underlying nuclear import of the NeuroD1/E47 heterodimer. In vitro nuclear import assays indicated that importin α family members are the major nuclear import receptors for E47. However, inhibition of importin α resulted in cytoplasmic retention of E47 that could be rescued by its binding partner, NeuroD1, through heterodimerization. In addition, nuclear import of NeuroD1 was importin α independent but importin β1 dependent. In primary neurons, localization of endogenous E47 was not affected by importin α inhibition, suggesting that neuronal E47 could be imported into the nucleus as a heterodimer with NeuroD1 by using importin β1 alone. We also found that E47 had similar nuclear import characteristics in C2C12 cells, where E47 heterodimerized with MyoD, another helix-loop-helix protein, suggesting functional conservation within the same family of transcription factors. Collectively, our data reveal that E47 is imported into the nucleus via multiple pathways, depending on the molecular binding mode, establishing a previously uncharacterized cross-talk between two distinct nuclear import pathways.
Phosphorylation of the Ndc80 complex protein, HEC1, by Nek2 kinase modulates chromosome alignment and signaling of the spindle assembly checkpoint
Authors: Wei Randy , Ngo Bryan , Wu Guikai , Lee Wen-Hwa
Published: August 2011

The spindle assemble checkpoint (SAC) is critical for accurate chromosome segregation. Hec1 contributes to chromosome segregation in part by mediating SAC signaling and chromosome alignment. However, the molecular mechanism by which Hec1 modulates checkpoint signaling and alignment remains poorly understood. We found that Hec1 serine 165 (S165) is preferentially phosphorylated at kinetochores. Phosphorylated Hec1 serine 165 (pS165) specifically localized to kinetochores of misaligned chromosomes, showing a spatiotemporal distribution characteristic of SAC molecules. Expressing an RNA interference (RNAi)-resistant S165A mutant in Hec1-depleted cells permitted normal progression to metaphase, but accelerated the metaphase-to-anaphase transition. The S165A cells were defective in Mad1 and Mad2 localization to kinetochores, regardless of attachment status. These cells often entered anaphase with lagging chromosomes and elicited increased segregation errors and cell death. In contrast, expressing S165E mutant in Hec1-depleted cells triggered defective chromosome alignment and severe mitotic arrest associated with increased Mad1/Mad2 signals at prometaphase kinetochores. A small portion of S165E cells eventually bypassed the SAC but showed severe segregation errors. Nek2 is the primary kinase responsible for kinetochore pS165, while PP1 phosphatase may dephosphorylate pS165 during SAC silencing. Taken together, these results suggest that modifications of Hec1 S165 serve as an important mechanism in modulating SAC signaling and chromosome alignment.
The Relationship between Food Assistance and Health: A Review of the Literature and Empirical Strategies for Identifying Program Effects
Authors: Meyerhoefer Chad D. , Yang Muzhe
Published: August 2011

There is a large and growing body of literature on the impact of food assistance programs on body weight and health. We review this literature in the context of an economic model of consumption and time allocations in order to elucidate the multiple pathways between food assistance and health. We then present a general empirical framework for comparing and contrasting different identification strategies, some of which have been used to evaluate food assistance programs, from the treatment effects literature. In addition to discussing the most widely used methods, we highlight recent advances that may be of interest to food assistance researchers.
Automatic detection of changes in the dynamics of delayed stochastic gene networks and in vivo production of RNA molecules in Escherichia coli
Authors: Mäkelä Jarno , Huttunen Heikki , Kandhavelu Meenakshisundaram , Yli-Harja Olli , Ribeiro Andre S.
Published: August 2011

Motivation: Production and degradation of RNA and proteins are stochastic processes, difficulting the distinction between spurious fluctuations in their numbers and changes in the dynamics of a genetic circuit. An accurate method of change detection is key to analyze plasticity and robustness of stochastic genetic circuits.

Results: We use automatic change point detection methods to detect non-spurious changes in the dynamics of delayed stochastic models of gene networks at run time. We test the methods in detecting changes in mean and noise of protein numbers, and in the switching frequency of a genetic switch. We also detect changes, following genes' silencing, in the dynamics of a model of the core gene regulatory network of Saccharomyces cerevisiae with 328 genes. Finally, from images, we determine when RNA molecules tagged with fluorescent proteins are first produced in Escherichia coli. Provided prior knowledge on the time scale of the changes, the methods detect them accurately and are robust to fluctuations in protein and RNA levels.

Availability: Simulator: www.cs.tut.fi/~sanchesr/SGN/SGNSim.html

Contact:  andre.ribeiro@tut.fi

Supplementary information:  Supplementary data are available at Bioinformatics online.
Comparison of acute and chronic impact of adaptive servo‐ventilation on left chamber geometry and function in patients with chronic heart failure
Authors: Haruki Nobuhiko , Takeuchi Masaaki , Kaku Kyoko , Yoshitani Hidetoshi , Kuwaki Hiroshi , Tamura Masahito , Abe Haruhiko , Okazaki Masahiro , Tsutsumi Akizumi , Otsuji Yutaka
Published: August 2011

Aims

The aim of this study was to determine differences in the acute and chronic impact of adaptive servo‐ventilation (ASV) on left chamber geometry and function in patients with chronic heart failure (CHF).

Methods and results

An acute ASV study was performed to measure echocardiographic parameters before and 30 min after the initiation of ASV therapy in 30 CHF patients (mean age: 69 years, 23 male). The chronic effects of ASV therapy were also evaluated in 26 of these 30 patients over a mean follow‐up period of 24 weeks. Patients were divided into two groups according to the status of ASV therapy [ASV group (n= 15) and withdrawal group (n= 11)]. In the acute study, heart rate and blood pressure were significantly decreased 30 min after the ASV therapy compared with baseline. Stroke volume and cardiac output were significantly increased in conjunction with a reduction in systemic vascular resistance. Multivariate regression analysis revealed baseline E/e′ to be an independent predictor for absolute increase in cardiac output. In the chronic study, a significant reduction of left ventricular (LV)/left atrial (LA) volumes and the severity of mitral regurgitation (MR), and improved LV diastolic function parameters were noted in the ASV group. These beneficial effects were not observed in the withdrawal group.

Conclusion

The acute beneficial impact of ASV is mainly associated with the reduction of afterload resulting in an increase in stroke volume and cardiac output. In contrast, chronic ASV therapy produces LV and LA reverse remodelling resulting in an improvement in LV function and the severity of MR in patients with CHF.
Use of oral proton pump inhibitors is not associated with harm in patients with chronic heart failure in an ambulatory setting
Authors: Oudit Gavin Y. , Bakal Jeffrey A. , McAlister Finlay A. , Ezekowitz Justin A.
Published: August 2011

Aims

Proton pump inhibitors (PPIs) produce negative inotropic effects on the human myocardium at clinically relevant plasma concentrations. We conducted this study to determine whether PPI use was associated with excess mortality in patients with both ischaemic and non‐ischaemic heart failure (HF).

Methods and results

The impact of PPIs on all‐cause mortality was examined using a population‐based cohort of Alberta residents over the age of 65 with a diagnosis of HF, logistic regression analysis, and a nested case–control study were used to examine the association between current medication use and mortality. Compared with non‐PPI users (n= 15 676, 71% of the HF cohort), PPI users (n= 6431, 29% of the HF cohort) were more likely to be women and had more co‐morbidities. Mortality in the first year after diagnosis of HF was 32% (n= 5659) in PPI non‐users and 26% (n= 1153) in PPI users. Logistic regression modelling showed that PPI use was associated with a relative reduction in mortality rates compared with non‐use [adjusted odds ratio (aOR) = 0.87, 95% confidence interval (CI) 0.81–0.93]. Nested case–control analysis of the 5815 patients who died matched to 9934 controls, revealed that current PPI use was not associated with excess mortality (aOR 0.88, 95%CI 0.77–1.01), while use of angiotensin‐converting enzyme inhibitors/angiotensin receptor blocker s (aOR 0.70, 95%CI 0.62–0.79) or beta‐blockers (aOR 0.57, 95%CI 0.50–0.66), was associated with a relative reduction in mortality.

Conclusion

The use of PPIs in patients with HF is common. Despite in vitro concerns about negative inotropic effects with PPIs, there is no association with increased risk of mortality in chronic HF patients who use PPIs in an ambulatory setting.
First Report of Iris yellow spot virus Infecting Onion in Kenya and Uganda
Authors: Birithia R. , Subramanian S. , Pappu H. R. , Sseruwagi P. , Muthomi J. W. , Narla R. D.
Published: August 2011

Onion (Allium cepa L.) is one of the key vegetables produced by small-holder farmers for the domestic markets in Sub-Saharan Africa. Biotic factors, including infestation by thrips pests such as Thrips tabaci Lindeman, can inflict as much as 60% yield loss. Iris yellow spot virus (IYSV; family Bunyaviridae, genus Tospovirus) transmitted by T. tabaci is an economically important viral pathogen of bulb and seed onion crops in many onion-growing areas of the world (2,4). In Africa, IYSV has been reported in Reunion (1) and South Africa (3). In September 2009, symptoms suspected to be caused by IYSV were observed on onions and leeks cultivated in Nairobi, Kenya. Symptoms consisted of spindle-shaped, straw-colored, irregular chlorotic lesions with occasional green islands on the leaves. The presence of the virus was confirmed with IYSV-specific Agdia Flash kits (Agdia Inc., Elkart, IN). Subsequently, surveys were undertaken in small-holder farms in onion production areas of Makueni (January 2010) and Mwea (August 2010) in Kenya and Kasese (January 2010) and Rwimi (January 2010) in Uganda. The incidence of disease in these locations ranged between 27 and 72%. Onion leaves showing symptoms of IYSV infection collected from both locations tested positive for the virus by double-antibody sandwich-ELISA with IYSV-specific antiserum (Agdia Inc). IYSV infection was confirmed by reverse transcription-PCR with primers IYSV-465c: 5′-AGCAAAGTGAGAGGACCACC-3′ and IYSV-239f: 5′-TGAGCCCCAATCAAGACG3′ (3) as forward and reverse primers, respectively. Amplicons of approximately 240 bp were obtained from all symptomatic test samples but not from healthy and water controls. The amplicons were cloned and sequenced from each of the sampled regions. Consensus sequence for each isolate was derived from at least three clones. The IYSV-Kenya isolate (GenBank Accession No. HQ711616) had the highest nucleotide sequence identity of 97% with the corresponding region of IYSV isolates from Sri Lanka (GenBank Accession No. GU901211), followed by the isolates from India (GenBank Accession Nos. EU310287 and EU310290). The IYSV-Uganda isolate (GenBank Accession No. HQ711615) showed the highest nucleotide sequence identity of 95% with the corresponding region of IYSV isolates from Sri Lanka (GenBank Accession No. GU901211) and India (95% with GenBank Accession Nos. EU310274 and EU310297). To our knowledge, this is the first report of IYSV infecting onion in Kenya and Uganda. Further surveys and monitoring of IYSV incidence and distribution in the region, along with its impact on the yield, are under investigation.

References: (1) L. J. du Toit et al. Plant Dis. 91:1203, 2007. (2) D. H. Gent et al. Plant Dis. 88:446, 2004. (3) H. R. Pappu et al. Plant Dis 92:588, 2008. (4) H. R. Pappu et al. Virus Res. 141:219, 2009.
Chemical Compounds Effective Against the Citrus Huanglongbing Bacterium ‘Candidatus Liberibacter asiaticus’ In Planta
Authors: Zhang Muqing , Powell Charles A. , Zhou Lijuan , He Zhenli , Stover Ed , Duan Yongping
Published: August 2011

Citrus Huanglongbing (HLB) is one of the most destructive diseases of citrus worldwide and is threatening the survival of the Floridian citrus industry. Currently, there is no established cure for this century-old and emerging disease. As a possible control strategy for citrus HLB, therapeutic compounds were screened using a propagation test system with ‘Candidatus Liberibacter asiaticus’-infected periwinkle and citrus plants. The results demonstrated that the combination of penicillin and streptomycin (PS) was effective in eliminating or suppressing the ‘Ca. L. asiaticus’ bacterium and provided a therapeutically effective level of control for a much longer period of time than when administering either antibiotic separately. When treated with the PS, ‘Ca. L. asiaticus’-infected periwinkle cuttings achieved 70% of regeneration rates versus <50% by other treatments. The ‘Ca. L. asiaticus’ bacterial titers in the infected periwinkle plants, as measured by quantitative real-time polymerase chain reaction, decreased significantly following root soaking or foliar spraying with PS. Application of the PS via trunk injection or root soaking also eliminated or suppressed the ‘Ca. L. asiaticus’ bacterium in the HLB-affected citrus plants. This may provide a useful tool for the management of citrus HLB and other Liberibacter-associated diseases.
How to infer gene networks from expression profiles, revisited
Authors: Penfold Christopher A. , Wild David L.
Published: August 2011

Inferring the topology of a gene-regulatory network (GRN) from genome-scale time-series measurements of transcriptional change has proved useful for disentangling complex biological processes. To address the challenges associated with this inference, a number of competing approaches have previously been used, including examples from information theory, Bayesian and dynamic Bayesian networks (DBNs), and ordinary differential equation (ODE) or stochastic differential equation. The performance of these competing approaches have previously been assessed using a variety of
in silico
and
in vivo
datasets. Here, we revisit this work by assessing the performance of more recent network inference algorithms, including a novel non-parametric learning approach based upon nonlinear dynamical systems. For larger GRNs, containing hundreds of genes, these non-parametric approaches more accurately infer network structures than do traditional approaches, but at significant computational cost. For smaller systems, DBNs are competitive with the non-parametric approaches with respect to computational time and accuracy, and both of these approaches appear to be more accurate than Granger causality-based methods and those using simple ODEs models.
Functional characterization of the essential tail anchor of the herpes simplex virus type 1 nuclear egress protein pUL34
Authors: Ott Melanie , Tascher Georg , Haßdenteufel Sarah , Zimmermann Richard , Haas Jürgen , Bailer Susanne M.
Published: August 2011

Release of herpes simplex virus type 1 (HSV-1) nucleocapsids from the host nucleus relies on the nuclear egress complex consisting of the two essential proteins pUL34 and pUL31. The cytoplasmically exposed N-terminal region of pUL34 interacts with pUL31, while a hydrophobic region followed by a short luminal part mediates membrane association. Based on its domain organization, pUL34 was postulated to be a tail-anchor (TA) protein. We performed a coupledin vitrotranscription/translation assay to show that membrane insertion of pUL34 occurs post-translationally. Transient transfection and localization experiments in mammalian cells were combined with HSV-1 bacterial artificial chromosome mutagenesis to reveal the functional properties of the essential pUL34 TA. Our data show that a minimal tail length of 15 residues is sufficient for nuclear envelope targeting and pUL34 function. Permutations of the pUL34 TA with orthologous regions of human cytomegalovirus pUL50 or Epstein–Barr virus pBFRF1 as well as the heterologous HSV-1 TA proteins pUL56 or pUS9 or the cellular TA proteins Bcl-2 and Vamp2 revealed that nuclear egress tolerates TAs varying in sequence and hydrophobicity, while a non-α-helical membrane anchor failed to complement the pUL34 function. In conclusion, this study provides the first mechanistic insights into the particular role of the TA of pUL34 in membrane curving and capsid egress from the host nucleus.
Transcriptional profiling of host gene expression in chicken liver tissues infected with oncogenic Marek’s disease virus
Authors: Chen Cuiying , Li Hongmei , Xie Qingmei , Shang Huiqin , Ji Jun , Bai Siwei , Cao Yongchang , Ma Yulin , Bi Yingzuo
Published: August 2011

Marek’s disease virus (MDV), one of the most potent oncogenic herpesviruses, leads to highly contagious immunosuppressive and neoplastic disease in susceptible chickens. Previous studies mainly focused on the roles of host genes modulated by MDV in the virological rather than the neoplastic stage of disease. To investigate the molecular mechanisms of tumorigenesis in Marek’s disease further, a microarray analysis with Affymetrix Gene-Chip Chicken Genome Arrays was performed in a non-lymphoid tissue liver during the neoplastic stage. Of the 32 773 chicken transcriptions arrayed on a chip, 269 genes were significantly differentially expressed during the neoplastic stage caused by MDV infection (upregulated, 175; downregulated, 94). The altered genomic expression of 15 randomly selected genes was confirmed by real-time RT-PCR. Biological functions and pathways of the group of 269 differentially expressed genes were analysed by using a bioinformatics tool (ipa, Ingenuity Pathway Analysis). The results revealed that 19 possible gene networks with intermolecular connections and 22 significant metabolic and signalling pathways (P≤0.05) among 137 differentially expressed genes. These 137 genes were classified into a number of functional groups that included genetic disorder, cancer, cellular growth and proliferation, and cell death. In summary, the investigation of global host-gene expression, providing the biological functions of differentially expressed genes in lymphoid tumours of the liver in response to MDV infections, may contribute to a basic understanding of the molecular mechanisms involved in tumorigenesis following MDV infection.
General blockade of human cytomegalovirus immediate-early mRNA expression in the S/G2 phase by a nuclear, Daxx- and PML-independent mechanism
Authors: Zydek Martin , Uecker Ralf , Tavalai Nina , Stamminger Thomas , Hagemeier Christian , Wiebusch Lüder
Published: August 2011

The onset of human cytomegalovirus (HCMV) lytic replication is strictly controlled by the host cell division cycle. Although viral entry of S/G2-phase cells is unperturbed expression of major immediate-early (MIE) genes IE1 and IE2 is tightly blocked in these cells. Besides the finding that cyclin-dependent kinase (CDK) activity is required for IE1/IE2 repression little is known about the nature of this cell cycle-dependent block. Here, we show that the block occurs after nuclear entry of viral DNA and prevents the accumulation of IE1/IE2 mRNAs, suggesting an inhibition of transcription. Remarkably, the presence ofcis-regulatory regions of the MIE locus is neither sufficient nor necessary for IE1/IE2 repression in the S/G2 phase. Furthermore, the block of viral mRNA expression also affects other immediate-early transcribed regions, i.e. the US3 and UL36–38 gene loci. This suggests a mechanism of repression that acts in a general and not a gene-specific fashion. Such a nuclear, genome-wide repression of HCMV is typically mediated by the intrinsic immune defence at nuclear domain 10 (ND10) structures. However, we found that neither Daxx nor PML, the main players of ND10-based immunity, are required for the block to viral gene expression in the S/G2 phase. In addition, the viral tegument protein pp71 (pUL82), a major antagonist of the intrinsic immunity at pre-immediate-early times of infection, proved to be functional in S-phase cells. This suggests the existence of a yet undiscovered, CDK-dependent mechanism exerting higher-level control over immediate-early mRNA expression in HCMV-infected cells.
Comparative analysis of a highly variable region within the genomes of Spodoptera frugiperda ascovirus 1d (SfAV-1d) and SfAV-1a
Authors: Xue Jian-Li , Cheng Xiao-Wen
Published: August 2011

The recently discovered ascoviruses have a worldwide distribution. Here we report a new member of the family Ascoviridae, Spodoptera frugiperda ascovirus 1d (SfAV-1d) with a variable region in the genome. Restriction fragment length polymorphism, Southern hybridization and genome sequencing analyses confirmed that SfAV-1d and the earlier reported SfAV-1a are closely related but are not identical. The genome size of SfAV-1d is approximately 100 kbp, which is about 57 kbp smaller than SfAV-1a. The SfAV-1d genome has a major deletion of 14 kbp that corresponds to one of the inverted repeat (IR) regions of SfAV-1a. Cloning and sequencing revealed that the region flanking the deletion within the SfAV-1d genome is highly variable. In all the variants of this region, the whole IR region is missing, with 88.2 % of the variants missing part of or the whole adjacent SfAV-1a ORF71, 94.1 % missing part of or the whole of adjacent ORF72 and 64.6 % missing part of or the whole of ORF73.
Risk of seropositivity to multiple oncogenic human papillomavirus types among human immunodeficiency virus-positive and -negative Ugandan women
Authors: Namujju P. B. , Waterboer T. , Banura C. , Muwonge R. , Mbidde E. K. , Byaruhanga R. , Muwanga M. , Surcel H.-M. , Pawlita M. , Lehtinen M.
Published: August 2011

To understand the prospects for human papillomavirus (HPV) mass vaccination in the setting of a developing country, we studied the co-occurrence of seropositivity to multiple high-risk (hr) HPV types among HIV-positive and HIV-negative Ugandan women. Our seroepidemiological study was conducted among 2053 women attending antenatal clinics. Sera were analysed for antibodies to eight hrHPV types of the α-7 (18/45) and α-9 (16/31/33/35/52/58) species of HPV by using a multiplex serology assay. Our results show that seropositivity for greater than one hrHPV type was as common (18 %) as for a single type (18 %). HIV-positive women had higher HPV16, HPV18 and HPV45 seroprevalences than HIV-negative women. In multivariate logistic regression analysis, age (>30 years) and level of education (secondary school and above) reduced the risk, whereas parity (>5) and HIV-positivity increased the risk for multiple hrHPV seropositivity. However, in stepwise logistic regression analyses, HIV-status remained the only independent, stand-alone risk factor [odds ratio (OR) 1.7, 95 % confidence interval (CI) 1.0–2.8). On the other hand, the risk of HPV16 or HPV18 seropositive women, as compared to HPV16 or HPV18 seronegative women, for being seropositive to other hrHPV types was not significantly different when they were grouped by HIV-status (ORHPV16/HIV+ 12, 95 % CI 4.5–32 versus ORHPV16/HIV− 22, 95 % CI 15–31 and ORHPV18/HIV+ 58, 95 % CI 14–242 versus ORHPV18/HIV− 45, 95 % CI 31–65). In conclusion, seropositivity to HPV16, HPV18 and to non-vaccine hrHPV types is common in Ugandan women, suggesting that there is little natural cross-protective immunity between the types. HIV-positivity was an independent, stand-alone, albeit moderate risk factor for multiple hrHPV seropositivity. HPV mass vaccination may be the most appropriate method in the fight against cervical cancer in the Ugandan population.
Fish response to the temporal hierarchy of the natural flow regime in the Daly River, northern Australia
Authors: Stewart‐Koster B. , Olden J. D. , Kennard M. J. , Pusey B. J. , Boone E. L. , Douglas M. , Jackson S.
Published: August 2011

In this study, relationships between flow variation across multiple temporal scales and the distribution and abundance of three fish species, western rainbowfish Melanotaenia australis, sooty grunter Hephaestus fuliginosus and barramundi Lates calcarifer were examined at eight sampling reaches in the Daly River, Northern Territory, Australia. Discharge was highly seasonal during the study period of 2006–2010 with a distinct wet–dry discharge pattern. Significant catchment‐wide correlations were identified between species abundance and hydrologic variables across several scales describing the magnitude and variability of flow. A Bayesian hierarchical model which accounted for >80% of variation in abundances for all species and age classes (i.e. juvenile and adult), identified the extent to which the influence of short‐term flow variation was dependent upon the historical flow regime. There were distinct ontogenetic differences in these relationships for H. fuliginosus, with variability of recent flows having a negative effect on juveniles which was stronger at locations with higher historical mean daily flow. Lates calcarifer also displayed ontogenetic differences in relationships to flow variation with adults showing a positive association with increase in recent flows and juveniles showing a negative one. The effect of increased magnitude of wet‐season flows on M. australis was negative in locations with lower historical mean daily flow but positive in locations with higher historical mean daily flow. The results highlighted how interactions between multiple scales of flow variability influence the abundance of fish species according to their life‐history requirements.
Pharmacokinetics, adverse effects and tolerability of a novel analogue of human pancreatic polypeptide, PP 1420
Authors: Tan Tricia M. , Field Benjamin C. T. , Minnion James S. , Cuenco‐Shillito Joyceline , Chambers Edward S. , Zac‐Varghese Sagen , Brindley Charlie J. , Mt‐Isa Shahrul , Fiorentino Francesca , Ashby Deborah , Ward Ian , Ghatei Mohammad A. , Bloom Stephen R.
Published: August 2011

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT

• Human pancreatic polypeptide (hPP) is a natural pancreatic hormone that suppresses appetite after meals.

• When exogenous hPP is given to healthy human volunteers, it causes a reduction in food intake.

• PP 1420 is a longer acting analogue of hPP that has been developed as a novel treatment for obesity.

WHAT THIS STUDY ADDS

• PP 1420 has been shown to be well tolerated in healthy human volunteers.

• PP 1420 has been shown to have an extended terminal elimination half‐life compared with hPP.

AIMS The objectives of this phase 1 study were to confirm the tolerability of single ascending subcutaneous doses of PP 1420 in healthy subjects, to assess its adverse effects and to investigate the drug's pharmacokinetics and dose proportionality.

METHODS This was a double‐blind, placebo‐controlled, randomized study. There were three dosing periods. Each subject (n= 12) was randomized to receive one dose of placebo and two ascending doses of PP 1420, given as a subcutaneous injection. Blood samples were taken over 24 h to assess pharmacokinetics. Standard safety and laboratory data were collected. The primary endpoint was the tolerability of PP 1420. The secondary endpoint was exposure to PP 1420 as assessed by Cmax and AUC(0,∞).

RESULTS PP 1420 was well tolerated by all subjects with no serious adverse effects. Following single subcutaneous doses of PP 1420 at 2, 4 and 8 mg to male subjects, Cmax was reached at a median tmax of approximately 1 h post dose (range 0.32–2.00 h). Thereafter, plasma concentrations of PP 1420 declined with geometric mean apparent terminal elimination t1/2 ranging from 2.42–2.61 h (range 1.64–3.95 h) across all dose levels.

CONCLUSIONS Subcutaneous PP 1420 was well tolerated in healthy human subjects at single doses between 2–8 mg, with no tolerability issues arising. Where observed, adverse events were not serious, and there was no evidence of a dose‐relationship to frequency of adverse events. The results therefore support the conduct of clinical trials to investigate efficacy, tolerability and pharmacokinetics during repeated dosing.
Dental caries and its association with diet and dental erosion in Libyan schoolchildren
Authors: HUEW RASMIA , WATERHOUSE PAULA , MOYNIHAN PAULA , KOMETA SIMON , MAGUIRE ANNE
Published: August 2011

International Journal of Paediatric Dentistry 2011; 22: 68–76

Background.  The change towards a more Westernised diet in Libya may increase the risk of caries and erosion in children.

Aims.  To investigate any association between dental caries, dental erosion, and potential dietary risk factors in Libyan schoolchildren.

Methods.  A random sample of 791 schoolchildren aged 12 years underwent dental examination for caries and erosion and completed a questionnaire to provide dietary data. Dental caries was assessed using the WHO (Oral Health Surveys: Basic Methods, 1997) criteria. Erosion was assessed using UK National Diet and Nutrition Survey (NDNS, Young People Aged 4–18 years. Volume 2: Report of the Oral Health Survey, 2000) criteria. Associations between caries and dietary variables were investigated through bivariate and multivariate analyses.

Results.  Of the 791 12‐year olds, 57.8% (457) had caries experience and 40.8% (323) had experience of erosion. One hundred and ninety‐two subjects (42%) of the subjects with caries experience also had erosion, whilst 131 subjects (39.2%) of the 334 without caries had clinical signs of erosion (P = 0.464; OR, 1.123; 95% CI, 0.842, 1.497). There was no statistically significantly relationship between dental caries and dental erosion. Frequency of consumption of fruit‐based sugared drinks was statistically significantly positively associated with experience of caries (P = 0.002).

Conclusions.  Dental caries experience was associated with frequency of consumption of sugared dietary items but not with dental erosion.
Nursing the patient with complex communication needs: time as a barrier and a facilitator to successful communication in hospital
Authors: Hemsley Bronwyn , Balandin Susan , Worrall Linda
Published: August 2011

hemsley b., balandin s. & worrall l. (2012) Nursing the patient with complex communication needs: time as a barrier and a facilitator to successful communication in hospital. Journal of Advanced Nursing68(1), 116–126.

Background.  Effective nurse–patient communication is an essential aspect of health care. Time to communicate, however, is limited and subject to workload demands. Little is known about how nurses manage this ‘lack of time’ when caring for patients with developmental disability and complex communication needs, who typically communicate at a slow rate.

Aim.  The aim of this study was to investigate nurses’ expressed concepts of ‘time’ in stories about communicating with patients with developmental disability and complex communication needs in hospital.

Method.  In 2009, 15 hospital nurses from a range of wards in two metropolitan hospitals participated in interviews about barriers to and strategies for successful communication with patients with developmental disability and complex communication needs in hospital. The data were analysed using narrative inquiry methodology and the stories verified with the participants.

Results.  Nurses identified ‘time’ as a barrier and a facilitator to successful communication. Time as a barrier was related thematically to avoiding direct communication and preferring that family or paid carers communicated on behalf of the patient. Time as a facilitator was related to valuing communication, investing extra time, and to applying a range of adaptive communication strategies to establish successful communication.

Conclusions.  Time is perceived by nurses as both an enemy and friend for improving communication. Nurses who perceive that communication takes too long may avoid communication and miss opportunities to improve communication through increased familiarity with the person’s communication methods. Those who take time to communicate narrate applying a range of strategies to achieve success in basic needs communication.