bluuebunny/crossref_metadata_2025 huggingface dataset:
GABAergic transmission and enhanced modulation by opioids and endocannabinoids in adult rat rostral ventromedial medulla
Authors: Li Ming‐Hua , Suchland Katherine L. , Ingram Susan L.
Published: October 2014

Key points

Electrical stimulation of the rostral ventromedial medulla (RVM) facilitates pain behaviours in neonates but inhibits these behaviours in adults. The cellular mechanisms underlying these changes in RVM modulation of pain behaviours are not known.

We optimized whole‐cell patch‐clamp recordings for RVM neurons in animals older than postnatal day 30 and compared the results to postnatal day 10–21 animals.

Our results demonstrate that the γ‐aminobutyric acid (GABA) release is lower and opioid effects are more evident in adult rats compared to early postnatal rats.

A cannabinoid receptor antagonist significantly increased GABA release in mature but not in immature RVM neurons suggesting the presence of local endocannabinoid tone in mature RVM.

Neurons in the rostral ventromedial medulla (RVM) play critical and complex roles in pain modulation. Recent studies have shown that electrical stimulation of the RVM produces pain facilitation in young animals (postnatal (PN) day < 21) but predominantly inhibits pain behaviours in adults. The cellular mechanisms underlying these changes in RVM modulation of pain behaviours are not known. This is in part because whole‐cell patch‐clamp studies in RVM to date have been in young (PN day < 18) animals because the organization and abundance of myelinated fibres in this region make the RVM a challenging area for whole‐cell patch‐clamp recording in adults. Several neurotransmitter systems, including GABAergic neurotransmission, undergo developmental changes that mature by PN day 21. Thus, we focused on optimizing whole‐cell patch‐clamp recordings for RVM neurons in animals older than PN day 30 and compared the results to animals at PN day 10–21. Our results demonstrate that the probability of GABA release is lower and that opioid and endocannabinoid effects are more evident in adult rats (mature) compared to early postnatal (immature) rats. Differences in these properties of RVM neurons may contribute to the developmental changes in descending control of pain from the RVM to the spinal cord.
Activation of muscarinic receptors by ACh release in hippocampal CA1 depolarizes VIP but has varying effects on parvalbumin‐expressing basket cells
Authors: Bell L. Andrew , Bell Karen A. , McQuiston A. Rory
Published: October 2014

Key points

Optogenetically released acetylcholine (ACh) from medial septal afferents activates muscarinic receptors on both vasoactive intestinal peptide‐expressing (VIP) and parvalbumin‐expressing (PV) basket cells (BCs) in mouse hippocampal CA1.

ACh release depolarized VIP BCs whereas PV BCs depolarized, hyperpolarized or produced biphasic responses.

Depolarizing responses in VIP or PV BCs resulted in increased amplitudes and frequencies of spontaneous inhibitory postsynaptic currents (sIPSCs) in CA1 pyramidal neurons.

The instantaneous frequency of sIPSCs that result from excitation of VIP or PV BCs primarily occurred within the low gamma frequency band (25–50 Hz).

We investigated the effect of acetylcholine release on mouse hippocampal CA1 perisomatically projecting interneurons. Acetylcholine was optogenetically released in hippocampal slices by expressing the excitatory optogenetic protein oChIEF‐tdTomato in medial septum/diagonal band of Broca cholinergic neurons using Cre recombinase‐dependent adeno‐associated virally mediated transfection. The effect of optogenetically released acetylcholine was assessed on interneurons expressing Cre recombinase in vasoactive intestinal peptide (VIP) or parvalbumin (PV) interneurons using whole cell patch clamp methods. Acetylcholine released onto VIP interneurons that innervate pyramidal neuron perisomatic regions (basket cells, BCs) were depolarized by muscarinic receptors. Although PV BCs were also excited by muscarinic receptor activation, they more frequently responded with hyperpolarizing or biphasic responses. Muscarinic receptor activation resulting from ACh release increased the frequency of spontaneous inhibitory postsynaptic currents (sIPSCs) in downstream hippocampal CA1 pyramidal neurons with peak instantaneous frequencies occurring in both the gamma and theta bandwidths. Both PV and VIP BCs contributed to the increased sIPSC frequency in pyramidal neurons and optogenetic suppression of PV or VIP BCs inhibited sIPSCs occurring in the gamma range. Therefore, we propose acetylcholine release in CA1 has a complex effect on CA1 pyramidal neuron output through varying effects on perisomatically projecting interneurons.
Species‐dependent adaptation of the cardiac Na+/K+ pump kinetics to the intracellular Na+ concentration
Authors: Lewalle Alexandre , Niederer Steven A. , Smith Nicolas P.
Published: October 2014

Key Points

The sodium/potassium pump is a membrane protein that maintains the Na+ and K+ concentration gradients across the plasma membrane and is therefore a key component of the cardiac contraction mechanism.

Numerical models of the pump provide insight into its physiological role but most existing models neglect the significant known quantitative differences in pump kinetics between different species.

We developed a biophysical mechanistic modelling framework, designed specifically to enable a fully consistent species‐specific characterisation of the pump function.

We applied this framework to generate two separate species‐specific models, for the guinea pig and rat, and compared their respective kinetics in terms of objectively characterised biophysical parameters.

We incorporated our rat‐specific Na+/K+ ATPase model into a whole‐cell simulation and, for the first time, were able to reproduce measurements of the steady‐state intracellular sodium concentration as a function of pacing frequency.

The Na+/K+ ATPase (NKA) plays a critical role in maintaining ionic homeostasis and dynamic function in cardiac myocytes, within both the in vivo cell and in silico models. Physiological conditions differ significantly between mammalian species. However, most existing formulations of NKA used to simulate cardiac function in computational models are derived from a broad range of experimental sources spanning many animal species. The resultant inability of these models to discern species‐specific features is a significant obstacle to achieving a detailed quantitative and comparative understanding of physiological behaviour in different biological contexts. Here we present a framework for characterising the steady‐state NKA current using a biophysical mechanistic model specifically designed to provide a mechanistic explanation of the NKA flux supported by self‐consistent species‐specific data. We thus compared NKA kinetics specific to guinea‐ pig and rat ventricular myocytes. We observe that the apparent binding affinity for sodium in the rat is significantly lower, whereas the overall pump cycle rate is doubled, in comparison to the guinea pig. This sensitivity of NKA to its regulatory substrates compensates for the differences in Na+ concentrations between the cell types. NKA is thereby maintained within its dynamic range over a wide range of pacing frequencies in these two species, despite significant disparities in sodium concentration. Hence, by replacing a conventional generic NKA model with our rat‐specific NKA formula into a whole‐cell simulation, we have, for the first time, been able to accurately reproduce the action potential duration and the steady‐state sodium concentration as functions of pacing frequency.
Graduates welcome on-road: A culture shift in ambulance preceptorship made clear through retrospective analysis
Authors: Lazarsfeld-Jensen A , Bridges D , Carver H
Published: October 2014

A cultural shift in ambulance services has improved the experience of university- educated paramedics going on-road for the first time in New South Wales. In the “bad old days”, graduate paramedics reported routine rites of initiation, including barbed humour and contempt for skills gained in a university setting. Those educated in the on-road vocational system believed universities did not provide a tough enough environment for future paramedics. In this study, data were drawn from two projects involving university-educated paramedics who graduated between 1996 and 2011 and whose novice on-road experiences were several years apart. Comparative retrospective analysis of data provided evidence of a change in attitude towards New South Wales graduates, with an increase in support and inclusion. Novices with greater confidence in their own capacity was evidence of an attitudinal shift. Engaged on-road preceptors who won the respect of the novice was evidence of an increase in support. Inclusion had been a painful issue for both early cohorts of graduates and industry. Failure to fit is associated with attrition. Early in their on-road practice, recent novices reported a sense of belonging. The authors suggest that the shift in attitude could be attributed, first, to a critical mass of graduates on-road, including increasing numbers with postgraduate qualifications, and secondly, the stated preference of ambulance services in Australia to employ graduates.
The effectiveness of web-based interprofessional learning modules on health professional students’ behavioural intentions in relation to medication safety: A quasi- experimental study
Authors: Lapkin S , Levett-Jones T , Gilligan C
Published: October 2014

Background: Safe medication practices are a key focus of the global strategy to improve patient safety. Emerging evidence demonstrates that learning experiences focusing on developing collaborative skills such as mutual understanding of others’ roles, teamwork and interprofessional communication can enhance medication safety. However, interprofessional education for undergraduate students is limited by factors such timetabling restrictions and curricular constraints. Web-based approaches provide the opportunity to overcome these barriers. However, currently there is little empirical evidence of the effectiveness of web-based approaches in changing the behaviour of health professional students in relation to medication safety and collaborative practice.Aim: To examine the impact of web-based interprofessional learning modules on health professional students’ behavioural intentions in relation to medication safety and team work.Methods:  A quasi-experimental approach was employed to evaluate the effectiveness of the learning modules and 320 undergraduate health professions students were recruited.  Students were allocated to either an experimental (n= 155) or control group (n= 165). Participants in the experimental group completed a multimedia web-based learning module. The purpose-designed Theory of Planned Behaviour Medication Safety Questionnaire was used to compare behavioural intentions, attitudes, subjective norms and perceived behavioural control in relation to medication safety between the control and experimental groups.Results:  Participants in the experimental group demonstrated significantly greater intention to practice in a way that enhances medication safety and collaborative practice than those in the control group, as evidenced by higher scores on all outcomes: behavioural intention (p <  0.001); attitude (p < 0.001); perceived behavioural control (p= 0.107); and subjective norm (p = 0.115).Conclusion: The web-based interprofessional learning modules were an effective learning strategy for developing the behavioural intentions and attitudes inherent in safe medication practices.
Distribution of ion current density on a rotating spherical cap substrate during ion-assisted deposition
Authors: Marushka Viktor , Zabeida Oleg , Martinu Ludvik
Published: October 2014

The uniformity of ion density is critical for applications relying on the ion assisted deposition technique for the fabrication of the high quality thin films. The authors propose and describe here a method allowing one to calculate the ion density distribution on spherical substrate holders under stationary and rotating conditions for different positions of the ion source. The ion beam shape was approximated by a cosn function, and the ion current density was represented by a function inversely proportional to the distance from the ion source in accordance with our experimental results. As an example, a calculation of the current density distribution on the spherical cap substrate was performed for a broad beam ion source operated with an anode current of 3 A. The authors propose an approach for process optimization with respect to the ion source position and its inclination, in terms of uniformity and absolute value of the ion current density.
Simulation of a rising sun magnetron employing a faceted cathode with a continuous current source
Authors: Fernandez-Gutierrez Sulmer , Browning Jim , Lin Ming-Chieh , Smithe David N. , Watrous Jack
Published: November 2014

It has been proposed that gated field emitters could be used in place of conventional thermionic cathodes to control the current injection in a magnetron, both temporally and spatially. Since gated field emitters have to be fabricated on flat surfaces, a faceted cathode would be used to implement this approach. A 2D ten cavity, rising sun magnetron has been modeled using the particle-in-cell code vorpal. Cylindrical, five-sided, and ten-sided faceted cathodes were modeled to study the variation of magnetron operation due to the cathode shape. This work shows the results of the device performance employing three different cathode geometries with a typical continuous current source. The cathode voltage is −22.2 kV; magnetic field is 0.09 T; and linear current density is 326 A/m. The three models oscillated at the π-mode, at a frequency of 960 MHz for the cylindrical cathode and 957 MHz for the faceted cathodes. Simulations show a faster start up time for the ten-sided faceted cathode. This resulted in a reduced overall startup time of the device from 200 to 110 ns. A strong current instability was observed in the five-sided cathode case with a periodicity range from 250 to 350 ns. This instability was limited to the start-up period of the ten-sided cathode model; hence the ten-sided case was more stable.
Impact of surface morphology of Si substrate on performance of Si/ZnO heterojunction devices grown by atomic layer deposition technique
Authors: Hazra Purnima , Singh Satyendra Kumar , Jit Satyabrata
Published: October 2014

In this paper, the authors have investigated the structural, optical, and electrical characteristics of silicon nanowire (SiNW)/zinc oxide (ZnO) core–shell nanostructure heterojunctions and compared their characteristics with Si/ZnO planar heterojunctions to investigate the effect of surface morphology of Si substrate in the characteristics of Si/ZnO heterojunction devices. In this work, ZnO thin film was conformally deposited on both p-type 〈100〉 planar Si substrate and substrate with vertically aligned SiNW arrays by atomic layer deposition (ALD) method. The x-ray diffraction spectra show that the crystalline structures of Si/ZnO heterojunctions are having (101) preferred orientation, whereas vertically oriented SiNW/ZnO core–shell heterojunctions are having (002)-oriented wurtzite crystalline structures. The photoluminescence (PL) spectra of Si/ZnO heterojunctions show a very sharp single peak at 377 nm, corresponding to the bandgap of ZnO material with no other defect peaks in visible region; hence, these devices can have applications only in UV region. On the other hand, SiNW/ZnO heterojunctions are having band-edge peak at 378 nm along with a broad emission band, spreading almost throughout the entire visible region with a peak around 550 nm. Therefore, ALD-grown SiNW/ZnO heterojunctions can emit green and red light simultaneously. Reflectivity measurement of the heterojunctions further confirms the enhancement of visible region peak in the PL spectra of SiNW/ZnO heterojunctions, as the surface of the SiNW/ZnO heterojunctions exhibits extremely low reflectance (<3%) in the visible wavelength region compared to Si/ZnO heterojunctions (>20%). The current–voltage characteristics of both Si/ZnO and SiNW/ZnO heterojunctions are measured with large area ohmic contacts on top and bottom of the structure to compare the electrical characteristics of the devices. Due to large surface to-volume ratio of SiNW/ZnO core–shell heterojunction devices, the output current rating is about 130 times larger compared to their planar version at 2 V forward bias voltage. This higher output current rating can be exploited for fabricating high-performance nanoelectronic and optoelectronic devices in near future.
Plasmoelectric potentials in metal nanostructures
Authors: Sheldon Matthew T. , van de Groep Jorik , Brown Ana M. , Polman Albert , Atwater Harry A.
Published: October 2014

The conversion of optical power to an electric potential is of general interest for energy applications and is typically obtained via optical excitation of semiconductor materials. We developed a method for achieving electric potential that uses an all-metal geometry based on the plasmon resonance in metal nanostructures. In arrays of gold nanoparticles on an indium tin oxide substrate and arrays of 100-nanometer-diameter holes in 20-nanometer-thick gold films on a glass substrate, we detected negative and positive surface potentials during monochromatic irradiation at wavelengths below or above the plasmon resonance, respectively. We observed plasmoelectric surface potentials as large as 100 millivolts under illumination of 100 milliwatts per square centimeter. Plasmoelectric devices may enable the development of all-metal optoelectronic devices that can convert light into electrical energy.
X-Ray Structure of the Amidase Domain of AtzF, the Allophanate Hydrolase from the Cyanuric Acid-Mineralizing Multienzyme Complex
Authors: Balotra Sahil , Newman Janet , Cowieson Nathan P. , French Nigel G. , Campbell Peter M. , Briggs Lyndall J. , Warden Andrew C. , Easton Christopher J. , Peat Thomas S. , Scott Colin
Published: November 2014

The activity of the allophanate hydrolase from
Pseudomonas
sp. strain ADP, AtzF, provides the final hydrolytic step for the mineralization of
s
-triazines, such as atrazine and cyanuric acid. Indeed, the action of AtzF provides metabolic access to two of the three nitrogens in each triazine ring. The X-ray structure of the N-terminal amidase domain of AtzF reveals that it is highly homologous to allophanate hydrolases involved in a different catabolic process in other organisms (i.e., the mineralization of urea). The smaller C-terminal domain does not appear to have a physiologically relevant catalytic function, as reported for the allophanate hydrolase of
Kluyveromyces lactis
, when purified enzyme was tested
in vitro
. However, the C-terminal domain does have a function in coordinating the quaternary structure of AtzF. Interestingly, we also show that AtzF forms a large, ca. 660-kDa, multienzyme complex with AtzD and AtzE that is capable of mineralizing cyanuric acid. The function of this complex may be to channel substrates from one active site to the next, effectively protecting unstable metabolites, such as allophanate, from solvent-mediated decarboxylation to a dead-end metabolic product.
Improving Detection of Shiga Toxin-Producing Escherichia coli by Molecular Methods by Reducing the Interference of Free Shiga Toxin-Encoding Bacteriophages
Authors: Quirós Pablo , Martínez-Castillo Alexandre , Muniesa Maite
Published: November 2014

Detection of Shiga toxin-producing
Escherichia coli
(STEC) by culture methods is advisable to identify the pathogen, but recovery of the strain responsible for the disease is not always possible. The use of DNA-based methods (PCR, quantitative PCR [qPCR], or genomics) targeting virulence genes offers fast and robust alternatives. However, detection of
stx
is not always indicative of STEC because
stx
can be located in the genome of temperate phages found in the samples as free particles; this could explain the numerous reports of positive
stx
detection without successful STEC isolation. An approach based on filtration through low-protein-binding membranes and additional washing steps was applied to reduce free Stx phages without reducing detection of STEC bacteria. River water, food, and stool samples were spiked with suspensions of phage 933W and, as a STEC surrogate, a lysogen harboring a recombinant Stx phage in which
stx
was replaced by
gfp
. Bacteria were tested either by culture or by qPCR for
gfp
while phages were tested using qPCR targeting
stx
in phage DNA. The procedure reduces phage particles by 3.3 log
10
units without affecting the recovery of the STEC population (culturable or assessed by qPCR). The method is applicable regardless of phage and bacteria densities and is useful in different matrices (liquid or solid). This approach eliminates or considerably reduces the interference of Stx phages in the detection of STEC by molecular methods. The reduction of possible interference would increase the efficiency and reliability of genomics for STEC detection when the method is applied routinely in diagnosis and food analysis.
Evaluation of the Porcine Gastric Mucin Binding Assay for High-Pressure-Inactivation Studies Using Murine Norovirus and Tulane Virus
Authors: Li Xinhui , Chen Haiqiang
Published: November 2014

We compared the results of high-hydrostatic-pressure (HHP) inactivation of murine norovirus type 1 (MNV-1) and Tulane virus (TV) obtained by a porcine gastric mucin binding assay followed by quantitative reverse transcription-PCR (referred to here as the PGM-MB/PCR assay) and a plaque assay and evaluated HHP inactivation of a human norovirus (HuNoV) genogroup I genotype 1 (GI.1) strain and a HuNoV GII.4 strain by using the PGM-MB/PCR assay. Viruses were treated at different pressure levels for 2 min at 4 or 21°C in culture medium of neutral pH and in culture medium of pH 4 at 21°C. The log reductions of infectious MNV-1 and TV particles caused by HHP were assessed using the PGM-MB/PCR and plaque assays, while the log reductions of HuNoVs were assessed by the PGM-MB/PCR assay only. For TV and MNV-1, the two pressure inactivation curves obtained using the plaque and PGM-MB/PCR assays were almost identical at ≤2-log-reduction levels regardless of the treatment temperature and pH. Further increasing the pressure over the 2-log-reduction level resulted in higher log reductions of TV and MNV-1, as assessed by the plaque assay, but did not increase the log reductions, as assessed by the PGM-MB/PCR assay. HHP treatments could achieve maximum reductions of ∼3 and 3.5 log units for GI.1 and GII.4, respectively, as assessed by the PGM-MB/PCR assay. On the basis of these results, it can reasonably be concluded that the PGM-MB/PCR assay would very likely be able to estimate HHP inactivation of HuNoV at ≤2-log-reduction levels. It would also likely conservatively quantify HHP inactivation of the GI.1 strain at 2- to 3-log-reduction levels and the GII.4 strain at 2- to 3.5-log-reduction levels.
In Vitro
Activity of Glucosinolates and Their Degradation Products against Brassica-Pathogenic Bacteria and Fungi
Authors: Sotelo T. , Lema M. , Soengas P. , Cartea M. E. , Velasco P.
Published: November 2014

Glucosinolates (GSLs) are secondary metabolites found in
Brassica
vegetables that confer on them resistance against pests and diseases. Both GSLs and glucosinolate hydrolysis products (GHPs) have shown positive effects in reducing soil pathogens. Information about their
in vitro
biocide effects is scarce, but previous studies have shown sinigrin GSLs and their associated allyl isothiocyanate (AITC) to be soil biocides. The objective of this work was to evaluate the biocide effects of 17 GSLs and GHPs and of leaf methanolic extracts of different GSL-enriched
Brassica
crops on suppressing
in vitro
growth of two bacterial (
Xanthomonas campestris
pv. campestris and
Pseudomonas syringae
pv. maculicola) and two fungal (
Alternaria
brassicae
and
Sclerotinia
scletoriorum
)
Brassica
pathogens. GSLs, GHPs, and methanolic leaf extracts inhibited the development of the pathogens tested compared to the control, and the effect was dose dependent. Furthermore, the biocide effects of the different compounds studied were dependent on the species and race of the pathogen. These results indicate that GSLs and their GHPs, as well as extracts of different
Brassica
species, have potential to inhibit pathogen growth and offer new opportunities to study the use of
Brassica
crops in biofumigation for the control of multiple diseases.
Vegetation-Associated Impacts on Arctic Tundra Bacterial and Microeukaryotic Communities
Authors: Shi Yu , Xiang Xingjia , Shen Congcong , Chu Haiyan , Neufeld Josh D. , Walker Virginia K. , Grogan Paul
Published: November 2014

The Arctic is experiencing rapid vegetation changes, such as shrub and tree line expansion, due to climate warming, as well as increased wetland variability due to hydrological changes associated with permafrost thawing. These changes are of global concern because changes in vegetation may increase tundra soil biogeochemical processes that would significantly enhance atmospheric CO
2
concentrations. Predicting the latter will at least partly depend on knowing the structure, functional activities, and distributions of soil microbes among the vegetation types across Arctic landscapes. Here we investigated the bacterial and microeukaryotic community structures in soils from the four principal low Arctic tundra vegetation types: wet sedge, birch hummock, tall birch, and dry heath. Sequencing of rRNA gene fragments indicated that the wet sedge and tall birch communities differed significantly from each other and from those associated with the other two dominant vegetation types. Distinct microbial communities were associated with soil pH, ammonium concentration, carbon/nitrogen (C/N) ratio, and moisture content. In soils with similar moisture contents and pHs (excluding wet sedge), bacterial, fungal, and total eukaryotic communities were correlated with the ammonium concentration, dissolved organic nitrogen (DON) content, and C/N ratio. Operational taxonomic unit (OTU) richness, Faith's phylogenetic diversity, and the Shannon species-level index (
H
′) were generally lower in the tall birch soil than in soil from the other vegetation types, with pH being strongly correlated with bacterial richness and Faith's phylogenetic diversity. Together, these results suggest that Arctic soil feedback responses to climate change will be vegetation specific not just because of distinctive substrates and environmental characteristics but also, potentially, because of inherent differences in microbial community structure.
Draft Genome Sequence of Ristocetin-Producing Strain
Amycolatopsis
sp. Strain MJM2582 Isolated in South Korea
Authors: Kwun Min Jung , Cheng Jinhua , Yang Seung Hwan , Lee Dong-Ryung , Suh Joo-Won , Hong Hee-Jeon
Published: October 2014

The draft genome sequence of a ristocetin-producing
Amycolatopsis
strain (sp. MJM2582) isolated in South Korea is reported here. This strain has a genome of approximately 8.9 Mb containing 7,933 predicted genes, including the ristocetin cluster and 32 additional predicted secondary metabolite biosynthesis clusters.
Draft Genome Sequences of Two
Vibrionaceae
Species, Vibrio ponticus C121 and Photobacterium aphoticum C119, Isolated as Coral Reef Microbiota
Authors: Al-saari Nurhidayu , Meirelles Pedro Milet , Mino Sayaka , Suda Wataru , Oshima Kenshiro , Hattori Masahira , Ohkuma Moriya , Thompson Fabiano L. , Gomez-Gil Bruno , Sawabe Toko , Sawabe Tomoo
Published: October 2014

Here, the draft genome sequences of two
Vibrionaceae
,
Vibrio ponticus
C121 and
Photobacterium aphoticum
C119, which were isolated from the coral reef vicinity in Okinawa, Japan, are reported. The genome provides further insight into the genomic plasticity, biocomplexity, and ecophysiology, including pathogenicity and evolution, of these genera.
Draft Genome Sequences of Amoeba-Resistant
Aeromonas
spp. Isolated from Aquatic Environments
Authors: Kenzaka Takehiko , Nakahara Mayu , Higuchi Shoko , Maeda Kento , Tani Katsuji
Published: October 2014

Amoeba-resistant
Aeromonas veronii
ARB3 and
Aeromonas media
ARB13 and ARB20, which may be important intracellular pathogens of eukaryotic hosts, were isolated from pond and river waters. The draft genome sequences indicate that the strains harbor multiple protein secretion systems and toxins that induce disruption of the actin cytoskeleton.
Parental child-rearing attitudes are associated with functional constipation in childhood
Authors: van Dijk Marieke , de Vries Giel-Jan , Last Bob F , Benninga Marc A , Grootenhuis Martha A
Published: October 2014

Objective

Parenting factors are assumed to play a role in the development and maintenance of childhood constipation. However, knowledge about the association between parenting factors and childhood constipation is limited. This study investigates the association between parental child-rearing attitudes and prominent symptoms of functional constipation and assesses the strength of this association.

Design

Cross-sectional data of 133 constipated children and their parents were collected.

Setting

The gastrointestinal outpatient clinic at the Emma Children's Hospital in the Netherlands.

Patients

Children with functional constipation aged 4–18 years referred by general practitioners, school doctors and paediatricians.

Main outcome measures

Parental child-rearing attitudes were assessed by the Amsterdam version of the Parental Attitude Research Instrument (A-PARI). Symptoms of constipation in the child were assessed by a standardised interview. Negative binomial and logistic regression models were used to test the association between child-rearing attitudes and constipation symptoms.

Results

Parental child-rearing attitudes are associated with defecation and faecal incontinence frequency. Higher and lower scores on the autonomy attitude scale were associated with decreased defecation frequency and increased faecal incontinence. High scores on the overprotection and self-pity attitude scales were associated with increased faecal incontinence. More and stronger associations were found for children aged ≥6 years than for younger children.

Conclusions

Parental child-rearing attitudes are associated with functional constipation in children. Any parenting issues should be addressed during treatment of children with constipation. Referral to mental health services is needed when parenting difficulties hinder treatment or when the parent–child relationship is at risk.

Trial registration number

ISRCTN2518556.
An unusual constellation of congenital malformations in a single patient including partial anomalous pulmonary venous return, persistent left superior vena cava, aberrant pulmonary fissure, anomalous aortic arch, tracheal diverticulum and annular pancreas
Authors: Lapa T , Vedelago J , Kim H , Patrick E
Published: October 2014

We report a case of a male patient with a constellation of rare congenital anomalies consisting of: partial anomalous pulmonary venous return (PAPVR), persistent left superior vena cava, ‘bovine arch’ aortic branching, tracheal diverticulum, aberrant lung fissure anatomy and an annular pancreas. He had presented with a history of worsening dyspnoea. To the best of our knowledge, this is the first reported case of a single patient with such a vast constellation of anomalies. The radiological evaluations, epidemiology, embryology and clinical features of the anomalies are discussed. It is important for radiologists to be aware of each of these anomalies as distinct entities; detection of a single anomaly should alert to the possibility that further anatomic aberrancies may be present.
Gender comparisons in non-acute cardiac symptom recognition and subsequent help-seeking decisions: a mixed methods study protocol
Authors: Stain Nolan , Ridge Damien , Cheshire Anna
Published: November 2014

Introduction

Coronary heart disease (CHD) is one of the leading causes of death in both men and women worldwide. Despite the common misconception that CHD is a ‘man's disease’, it is now well accepted that women endure worse clinical outcomes than men following CHD-related events. A number of studies have explored whether or not gender differences exist in patients presenting with CHD, and specifically whether women delay seeking help for cardiac conditions. UK and overseas studies on help-seeking for emergency cardiac events are contradictory, yet suggest that women often delay help-seeking. In addition, no studies have looked at presumed cardiac symptoms outside an emergency situation. Given the lack of understanding in this area, an explorative qualitative study on the gender differences in help-seeking for a non-emergency cardiac events is needed.

Methods and analysis

A purposive sample of 20–30 participants of different ethnic backgrounds and ages attending a rapid access chest pain clinic will be recruited to achieve saturation. Semistructured interviews focusing on help-seeking decision-making for apparent cardiac symptoms will be undertaken. Interview data will be analysed thematically using qualitative software (NVivo) to understand any similarities and differences between the way men and women construct help-seeking. Findings will also be used to inform the preliminary development of a cardiac help-seeking intentions questionnaire.

Ethics and dissemination

Ethical approvals were sought and granted. Namely, the University of Westminster (sponsor) and St Georges NHS Trust REC, and the Trust Research and Development Office granted approval to host the study on the Queen Mary's Roehampton site. The study is low risk, with interviews being conducted on hospital premises during working hours. Investigators will disseminate findings via presentations and publications. Participants will receive a written summary of the key findings.
Is progression-free survival associated with a better health-related quality of life in patients with lung cancer? Evidence from two randomised trials with afatinib
Authors: Griebsch Ingolf , Palmer Michael , Fayers Peter M , Ellis Stuart
Published: November 2014

Objective

Progression-free survival (PFS) is frequently used as an efficacy end point in oncology clinical trials. However, there is limited evidence to support a positive association between improvement in PFS and improvement in health-related quality of life (HRQoL). The association between PFS and HRQoL was evaluated in two randomised trials.

Materials and methods

Data from two randomised controlled trials in patients with non-small cell lung cancer (NSCLC; LUX-Lung 1 and LUX-Lung 3) were used to investigate HRQoL in patients to determine whether tumour progression is accompanied by worsening HRQoL. HRQoL was assessed using the cancer-specific European Organization for Research and Treatment of Cancer (EORTC) core questionnaire QLQ-C30, the EuroQol EQ-5D overall utility and EuroQol EQ visual analogue scale. In both studies, progression was evaluated by independent review using RECIST criteria (primary end point) and also by investigator assessment. The relationship between tumour progression and HRQoL was evaluated using analysis of covariance and a longitudinal model.

Results

Compliance with HRQoL questionnaire completion was high. In both studies, patients with progression consistently experienced numerically poorer HRQoL at the time of progression than patients without progression. Differences in mean scores were statistically significant (p<0.05) between patients with and without progression at week 4 in all analyses in LUX-Lung 1 and at multiple time points in LUX-Lung 3. Results from the longitudinal analysis showed that progression (by independent review and investigator assessment) appears to have consistent negative impact on all three HRQoL measures (all p<0.0001).

Conclusions

Tumour progression in patients with NSCLC was associated with statistically significant worsening in HRQoL. These findings confirm the value of PFS as a patient-relevant end point.
Dural arteriovenous fistula (D-AVF): a rare cause of symmetrical bithalamic changes with free diffusivity changes
Authors: Bhogal Pervinder , Duxbury Oliver , Rangi Prem
Published: November 2014

We report a rare case of an encephalopathic presentation of a posterior fossa dural arteriovenous fistula with concomitant florid symmetrical bithalamic free diffusivity changes on MRI in a previously healthy individual. We describe the structural and functional imaging findings and the role of catheter angiography in diagnosis, prognostication and the timing and strategy in the management of this challenging vascular entity.
Transorbital superior ophthalmic vein sacrifice to preserve vision in ocular hypertension from aseptic cavernous sinus thrombosis
Authors: Ladner Travis R , Davis Brandon J , He Lucy , Mawn Louise A , Mocco J
Published: November 2014

Aseptic cavernous sinus thrombosis (CST) is rare and may clinically masquerade as a carotid cavernous fistula. Conventional management includes oral anticoagulation, but cases of ocular hypertension affecting vision may require more aggressive intervention. We report a case of a woman with spontaneous bilaterally occluded cavernous sinuses with elevated intraocular pressure (IOP), which resolved immediately following unilateral superior ophthalmic vein (SOV) sacrifice. She was subsequently placed on oral anticoagulants. By 4 months postoperatively her IOP was normalized and her vision had improved. Repeat angiography demonstrated stable venous filling, with some mild improvement of flow through the cavernous sinus. Coil-mediated sacrifice of the SOV might be an effective means to relieve ocular hypertension and preserve vision in the setting of aseptic CST.
Hierarchical Heteroclinics in Dynamical Model of Cognitive Processes: Chunking
Authors: Afraimovich Valentin S. , Young Todd R. , Rabinovich Mikhail I.
Published: October 2014

Combining the results of brain imaging and nonlinear dynamics provides a new hierarchical vision of brain network functionality that is helpful in understanding the relationship of the network to different mental tasks. Using these ideas it is possible to build adequate models for the description and prediction of different cognitive activities in which the number of variables is usually small enough for analysis. The dynamical images of different mental processes depend on their temporal organization and, as a rule, cannot be just simple attractors since cognition is characterized by transient dynamics. The mathematical image for a robust transient is a stable heteroclinic channel consisting of a chain of saddles connected by unstable separatrices. We focus here on hierarchical chunking dynamics that can represent several cognitive activities. Chunking is the dynamical phenomenon that means dividing a long information chain into shorter items. Chunking is known to be important in many processes of perception, learning, memory and cognition. We prove that in the phase space of the model that describes chunking there exists a new mathematical object — heteroclinic sequence of heteroclinic cycles — using the technique of slow–fast approximations. This new object serves as a skeleton of motions reflecting sequential features of hierarchical chunking dynamics and is an adequate image of the chunking processing.
A bonding model of entanglement for N-qubit graph states
Authors: Waegell Mordecai
Published: October 2014

The class of entangled N-qubit states known as graph states, and the corresponding stabilizer groups of N-qubit Pauli observables, have found a wide range of applications in quantum information processing and the foundations of quantum mechanics. A review of the properties of graph states is given and core spaces of graph states are introduced and discussed. A bonding model of entanglement for generalized graph states is then presented, in which the presence or absence of a bond between two qubits unequivocally specifies whether or not they are entangled. A physical interpretation of these bonds is given, along with a characterization of how they can be created or destroyed by entangling unitary operations and how they can be destroyed by local Pauli measurements. It is shown that local unitary operations do not affect the bond structure of a graph state, and therefore that if two graph states have nonisomorphic bond structures, then local unitary operations and/or reordering of qubits cannot change one into the other. Color multigraphs are introduced to depict the bond structures of graph states and to make some of their properties more apparent.
Coordination controlled atropoisomerism in phenanthroline-strapped porphyrins: A swinging affair
Authors: Vorburger Pauline , Wytko Jennifer A. , Weiss Jean
Published: October 2014

A phenanthroline-strapped porphyrin bearing two pyridine side arms attached to opposite meso positions was designed as a potential cytochrome c oxidase model and its zinc and copper(I)-zinc complexes were prepared. In the zinc porphyrin complex, the pyridine arms underwent a rapid exchange of their coordination to the zinc atom on the open face of the strapped-porphyrin, as demonstrated by variable temperature NMR studies. Only the β2 atropoisomer was observed for the zinc complex because of the rapid exchange. This swinging motion no longer occurred when Cu I was bound within the phenanthroline strap. In this Cu I / Zn II complex, the αβ atropoisomer predominated and one pyridine was coordinated to the zinc atom on the proximal side and the other pyridine was bound to the copper on the distal face. This work shows that allostery can be effective to control atropoisomery in phenanthroline strapped porphyrin as heme protein models.
Influence of additives in bulk heterojunction solar cells using magnesium tetraethynylporphyrin with triisopropylsilyl and anthryl substituents
Authors: Nakagawa Takafumi , Hatano Junichi , Matsuo Yutaka
Published: October 2014

We designed and synthesized anthryl-disubstituted magnesium tetraethynylporphyrin([{5,15-bis(anthracen-9′-yl)ethynyl}-10,20-bis{(triisopropylsilyl)ethynyl}porphyrinato] magnesium(II)), and applied it as an electron donor to solution-processed bulk heterojunction small molecule organic solar cells. The compound was characterized by single crystal X-ray crystallography as well as UV-vis light absorption spectrum showing the absorption maximum and onset at 700 and 740 nm, respectively. Organic solar cells using this compound and [6,6]-phenyl-C61-butyric acid methyl ester (PC61BM) as electron donor and acceptor, respectively, showed power conversion efficiency of 1.31% at the donor and acceptor ratio of 1:3. The use of pyridine as a coordinating additive increased power conversion efficiency to 1.61%, which was the best among tested additives, THF, pyradine, dioxane, and 1,8-diiodooctane.
Dynamic Ray Stabbing
Authors: Tao Yufei
Published: November 2014

We consider maintaining a dynamic set
S
of
N
horizontal segments in ℝ
2
such that, given a vertical ray
Q
in ℝ
2
, the segments in
S
intersecting
Q
can be reported efficiently. In the external memory model, we give a structure that consumes
O
(
N
/
B
) space, answers a query in
O
(log

B

N
+
K
/
B
) time (where
K
is the number of reported segments), and can be updated in
O
(log

B

N
) amortized time per insertion and deletion. With
B
set to a constant, the structure also works in internal memory, consuming space
O
(
N
), answering a query in
O
(log
N
+
K
) time, and supporting an update in
O
(log
N
) amortized time.
Approximating Rooted Steiner Networks
Authors: Cheriyan Joseph , Laekhanukit Bundit , Naves Guyslain , Vetta Adrian
Published: October 2014

The Directed Steiner Tree (DST) problem is a cornerstone problem in network design. We focus on the generalization of the problem with higher connectivity requirements. The problem with one root and two sinks is APX-hard. The problem with one root and many sinks is as hard to approximate as the directed Steiner forest problem, and the latter is well known to be as hard to approximate as the label cover problem. Utilizing previous techniques, we strengthen these results and extend them to undirected graphs. Specifically, we give an Ω(
k
ϵ
) hardness bound for the rooted
k
-connectivity problem in undirected graphs. As a consequence, we obtain an Ω(
k
ϵ
) hardness bound for the undirected subset
k
-connectivity problem. Additionally, we give a result on the integrality ratio of the natural linear programming relaxation of the directed rooted
k
-connectivity problem.
Minimizing Movement: Fixed-Parameter Tractability
Authors: Demaine Erik D. , Hajiaghayi Mohammadtaghi , Marx Dániel
Published: October 2014

We study an extensive class of movement minimization problems that arise from many practical scenarios but so far have little theoretical study. In general, these problems involve planning the coordinated motion of a collection of agents (representing robots, people, map labels, network messages, etc.) to achieve a global property in the network while minimizing the maximum or average movement (expended energy). The only previous theoretical results about this class of problems are about approximation and are mainly negative: many movement problems of interest have polynomial inapproximability. Given that the number of mobile agents is typically much smaller than the complexity of the environment, we turn to fixed-parameter tractability. We characterize the boundary between tractable and intractable movement problems in a very general setup: it turns out the complexity of the problem fundamentally depends on the treewidth of the minimal configurations. Thus, the complexity of a particular problem can be determined by answering a purely combinatorial question. Using our general tools, we determine the complexity of several concrete problems and fortunately show that many movement problems of interest can be solved efficiently.
Manufacturing for makers
Authors: Williams Amanda , Nadeau Bruno
Published: October 2014

The boundaries between 'the digital' and our everyday physical world are dissolving as we develop more physical ways of interacting with computing. This forum presents some of the topics discussed in the colorful multidisciplinary field of tangible and embodied interaction.
---Eva Hornecker, Editor
Myogenic responses occur on a beat-to-beat basis in the resting human limb
Authors: Fairfax Seth T. , Padilla Jaume , Vianna Lauro C. , Holwerda Seth W. , Davis Michael J. , Fadel Paul J.
Published: November 2014

Investigations of human myogenic responses typically use maneuvers that evoke robust changes in transmural pressure. Although this strategy has demonstrated peripheral myogenic responsiveness in the limbs, particularly in glabrous skin of the hand or foot, it has not considered the potential influence of the myogenic mechanism in beat-to-beat blood flow (BF) control during unprovoked rest. In the present study, we examined the interactions of spontaneous beat-to-beat mean arterial pressure (MAP; Finapres) with BF (Doppler ultrasound) supplying the forearm (brachial artery), lower leg (popliteal artery), and hand (ulnar artery) during 10 min of supine rest in healthy young men. Cross-correlation analyses revealed a negative association between MAP and BF, which was more prominent in the forearm than lower leg. The strongest correlation resulted when a −2-heart beat offset of MAP was applied ( R = −0.53 ± 0.04 in the forearm and −0.23 ± 0.05 in the leg, P < 0.05), suggesting an ∼2-s delay from instances of high/low MAP to low/high BF. Negatively associated episodes (high MAP/low BF and low MAP/high BF) outnumbered positively associated data ( P < 0.05). BF during low MAP values was greater than the steady-state average BF and vice versa. Wrist and ankle occlusion blunted the strength of correlations, homogenized the incidence of MAP and BF pairings, and reduced the magnitude of deviation from steady-state values. In contrast, these relationships were matched or accentuated for hand BF. Overall, these results suggest that myogenic responses are present and occur rapidly in human limbs during rest, overwhelm perfusion pressure gradient influences, and are primarily mediated by the distal limb circulation.