bluuebunny/crossref_metadata_2025 huggingface dataset:
Characterization of pyrimidine nucleoside phosphorylase of Mycoplasma hyorhinis: implications for the clinical efficacy of nucleoside analogues
Authors: Vande Voorde Johan , Gago Federico , Vrancken Kristof , Liekens Sandra , Balzarini Jan
Published: April 2012

In the present paper we demonstrate that the cytostatic and antiviral activity of pyrimidine nucleoside analogues is markedly decreased by a Mycoplasma hyorhinis infection and show that the phosphorolytic activity of the mycoplasmas is responsible for this. Since mycoplasmas are (i) an important cause of secondary infections in immunocompromised (e.g. HIV infected) patients and (ii) known to preferentially colonize tumour tissue in cancer patients, catabolic mycoplasma enzymes may compromise efficient chemotherapy of virus infections and cancer. In the genome of M. hyorhinis, a TP (thymidine phosphorylase) gene has been annotated. This gene was cloned, expressed in Escherichia coli and kinetically characterized. Whereas the mycoplasma TP efficiently catalyses the phosphorolysis of thymidine (Km=473 μM) and deoxyuridine (Km=578 μM), it prefers uridine (Km=92 μM) as a substrate. Our kinetic data and sequence analysis revealed that the annotated M. hyorhinis TP belongs to the NP (nucleoside phosphorylase)-II class PyNPs (pyrimidine NPs), and is distinct from the NP-II class TP and NP-I class UPs (uridine phosphorylases). M. hyorhinis PyNP also markedly differs from TP and UP in its substrate specificity towards therapeutic nucleoside analogues and susceptibility to clinically relevant drugs. Several kinetic properties of mycoplasma PyNP were explained by in silico analyses.
(Pro)renin and its receptors: pathophysiological implications
Authors: Batenburg Wendy W. , Danser A. H. Jan
Published: April 2012

Tissue angiotensin generation depends on the uptake of circulating (kidney-derived) renin and/or its precursor prorenin [together denoted as (pro)renin]. Since tissue renin levels are usually somewhat higher than expected based upon the amount of (renin-containing) blood in tissue, an active uptake mechanism has been proposed. Several candidates have been evaluated in the past three decades, including a renin-binding protein, the mannose 6-phosphate/insulin-like growth factor II receptor and the (pro)renin receptor. Although the latter seemed the most promising, its nanomolar affinity for renin and prorenin is several orders of magnitude above their actual (picomolar) levels in blood, raising doubt on whether (pro)renin–(pro)renin receptor interaction will ever occur in vivo. A wide range of in vitro studies have now demonstrated (pro)renin-receptor-induced effects at nanomolar renin and prorenin concentrations, resulting in a profibrotic phenotype. In addition, beneficial in vivo effects of the putative (pro)renin receptor blocker HRP (handle region peptide) have been observed, particularly in diabetic animal models. Despite these encouraging results, many other studies have reported either no or even contrasting effects of HRP, and (pro)renin-receptor-knockout studies revealed lethal consequences that are (pro)renin-independent, most probably due to the fact that the (pro)renin receptor co-localizes with vacuolar H+-ATPase and possibly determines the stability of this vital enzyme. The present review summarizes all of the recent findings on the (pro)renin receptor and its blockade, and critically compares it with the other candidates that have been proposed to mediate (pro)renin uptake from blood. It ends with the conclusion that the (pro)renin–(pro)renin receptor interaction, if it occurs in vivo, is limited to (pro)renin-synthesizing organs such as the kidney.
University: Dimensions of Building Clinical Training Teams in the Spanish-Bilingual Preschool Classroom
Authors: Epstein Laura
Published: April 2012

Building clinical training teams in the Spanish-bilingual preschool classroom is one way to prepare student clinicians for the diverse populations that future speech-language pathologists can expect to serve. Team-building supports the training needs of bilingual student clinicians, while also exposing monolingual student clinicians to bilingual children and colleagues.
Severe Drooling and Treatment With Botulinum Toxin
Authors: Bakke Merete , Bardow Allan , Møller Eigild
Published: April 2012

Severe drooling is associated with discomfort and psychosocial problems and may constitute a health risk. A variety of different surgical and non-surgical treatments have been used to diminish drooling, some of them with little or uncertain effect and others more effective but irreversible or with side effects. Based on clinical evidence, injection with botulinum toxin (BTX) into the parotid and submandibular glands is a useful treatment option, because it is local, reversible, and with few side effects, although it has to be repeated. The mechanism of BTX is a local inhibition of acetylcholine release, which diminishes receptor-coupled secretion and results in a flow rate reduction of 25–50% for 2–7 months.
Two-dimensional imaging of edge-localized modes in KSTAR plasmas unperturbed and perturbed by n=1 external magnetic fields
Authors: Yun G. S. , Lee W. , Choi M. J. , Lee J. , Park H. K. , Domier C. W. , Luhmann N. C. , Tobias B. , Donné A. J. H. , Lee J. H. , Jeon Y. M. , Yoon S. W. ,   KSTAR team
Published: April 2012

The temporal evolution of edge-localized modes (ELMs) has been studied using a 2-D electron cyclotron emission imaging system in the KSTAR tokamak. The ELMs are observed to evolve in three distinctive stages: the initial linear growth of multiple filamentary structures having a net poloidal rotation, the interim state of regularly spaced saturated filaments, and the final crash through a short transient phase characterized by abrupt changes in the relative amplitudes and distance among filaments. The crash phase, typically consisted of multiple bursts of a single filament, involves a complex dynamics, poloidal elongation of the bursting filament, development of a fingerlike bulge, and fast localized burst through the finger. Substantial alterations of the ELM dynamics, such as mode number, poloidal rotation, and crash time scale, have been observed under external magnetic perturbations with the toroidal mode number n = 1.
Infrared spectroscopy of carbonyl sulfide inside a pure 3He droplet
Authors: Sartakov Boris G. , Toennies J. Peter , Vilesov Andrey F.
Published: April 2012

The infrared spectrum of the ν3 band of an OCS (carbonyl sulfide) molecule embedded inside pure 3He droplets of about 12 × 103 atoms reported in 1998 [S. Grebenev, J. P. Toennies, and A. F. Vilesov, Science 279, 2083 (1998)] is carefully evaluated. The spectrum, which consists of a broad central peak and a distinct shoulder at lower energy, was analyzed by assuming unresolved rotational line structure of either a linear or a symmetric top. In each case the spectrum was fitted using either Lorentzian or Gaussian peak shapes with a preassigned fixed temperature of 0.15 K or a best fit temperature. Many of the fits describe the spectra nearly equally well and indicate broad R(0), R(1), and P(1) peaks but no Q-branch, a moment of inertia which is about a factor six greater than for the free molecule, and a temperature of 0.07 ± 0.06 K which is significantly less than 0.15 K determined for mixed 3He/4He droplets. The increased moment of inertia is consistent with about 11 attached 3He atoms which take part in the end-over-end rotations of the chromophore. The large line widths are attributed to creation of particle-hole pair excitations in the fermionic droplets.
Quantum dynamics in continuum for proton transport—Generalized correlation
Authors: Chen Duan , Wei Guo-Wei
Published: April 2012

As a key process of many biological reactions such as biological energy transduction or human sensory systems, proton transport has attracted much research attention in biological, biophysical, and mathematical fields. A quantum dynamics in continuum framework has been proposed to study proton permeation through membrane proteins in our earlier work and the present work focuses on the generalized correlation of protons with their environment. Being complementary to electrostatic potentials, generalized correlations consist of proton-proton, proton-ion, proton-protein, and proton-water interactions. In our approach, protons are treated as quantum particles while other components of generalized correlations are described classically and in different levels of approximations upon simulation feasibility and difficulty. Specifically, the membrane protein is modeled as a group of discrete atoms, while ion densities are approximated by Boltzmann distributions, and water molecules are represented as a dielectric continuum. These proton-environment interactions are formulated as convolutions between number densities of species and their corresponding interaction kernels, in which parameters are obtained from experimental data. In the present formulation, generalized correlations are important components in the total Hamiltonian of protons, and thus is seamlessly embedded in the multiscale/multiphysics total variational model of the system. It takes care of non-electrostatic interactions, including the finite size effect, the geometry confinement induced channel barriers, dehydration and hydrogen bond effects, etc. The variational principle or the Euler-Lagrange equation is utilized to minimize the total energy functional, which includes the total Hamiltonian of protons, and obtain a new version of generalized Laplace-Beltrami equation, generalized Poisson-Boltzmann equation and generalized Kohn-Sham equation. A set of numerical algorithms, such as the matched interface and boundary method, the Dirichlet to Neumann mapping, Gummel iteration, and Krylov space techniques, is employed to improve the accuracy, efficiency, and robustness of model simulations. Finally, comparisons between the present model predictions and experimental data of current-voltage curves, as well as current-concentration curves of the Gramicidin A channel, verify our new model.
Longitudinal static optical properties of hydrogen chains: Finite field extrapolations of matrix product state calculations
Authors: Wouters Sebastian , Limacher Peter A. , Van Neck Dimitri , Ayers Paul W.
Published: April 2012

We have implemented the sweep algorithm for the variational optimization of SU(2) ⊗ U(1) (spin and particle number) invariant matrix product states (MPS) for general spin and particle number invariant fermionic Hamiltonians. This class includes non-relativistic quantum chemical systems within the Born-Oppenheimer approximation. High-accuracy ab initio finite field results of the longitudinal static polarizabilities and second hyperpolarizabilities of one-dimensional hydrogen chains are presented. This allows to assess the performance of other quantum chemical methods. For small basis sets, MPS calculations in the saturation regime of the optical response properties can be performed. These results are extrapolated to the thermodynamic limit.
Short scale electrostatic vortices driven by electrons sheared flow parallel to external magnetic field in heavier ion plasmas
Authors: Ahmad Ali , Saleem H.
Published: April 2012

Nonlinear equations for an electrostatic perturbation in hybrid frequency range are derived in a magnetized heavier ion plasma assuming that the electrons are flowing with a sheared velocity along the initial external constant magnetic field B0zẑ. As a result of this current, the total zero-order magnetic field becomes sheared as B0=B0zẑ+B0y(x)ŷ. Such a system can give rise to unstable electrostatic waves under certain conditions. The solutions of the nonlinear equations are obtained in the form of dipolar vortices, which can play an important role in plasma transport across field lines. This work can be useful for the future experiments on sheared electron flows.
Nano-precipitates made of atomic pillars revealed by single atom detection in a Mg-Nd alloy
Authors: Lefebvre W. , Kopp V. , Pareige C.
Published: April 2012

We report on the atomic architecture of metastable precipitates in a model Mg-0.5 at. %Nd system. High resolution Z-contrast observations in scanning transmission electron microscopy demonstrate that a common elementary structure, made of Nd atomic pillars, is shared by precipitates involved in the early decomposition of the system. A combination of Z-contrast projections has been used to establish the accurate location of Nd atoms in the atomic pillars, therefore allowing the determination of structure and composition of precipitates. Other precipitates compositions are extrapolated by means of a quantitative analysis.
Enhancement-mode nanowire (nanobelt) field-effect-transistors with Schottky-contact source and drain electrodes
Authors: Yu Bin , Ye Yu , Wu Peicai , Dai Yu , Zhang Hui , Dai Lun
Published: April 2012

Enhancement-mode (E-mode) field-effect-transistors (FETs) have advantages in making high-speed and low power consumption devices. However, most reported nano-FETs work in the depletion-mode, because E-mode nano-FETs are usually difficult to be implemented. We suggest a device structure, based on which high-performance E-mode nanowire (NW) or nanobelt based FETs can be reliably fabricated. In this device structure, both source and drain electrodes form Schottky contact with the NW, and a top gate is long enough to control the entire conductive channel. The working principle is discussed in detail. This device structure is universal to semiconductor materials and has diverse application prospects.
A resistive pyrolytic radical source for gas-surface reaction studies
Authors: Lee David Y. , Jobbins Matthew M. , Kandel S. Alex
Published: April 2012

We describe a thermal gas cracker designed to produce low fluxes of gas-phase radicals for use in radical-surface reaction studies. A resistively heated thin piece of highly oriented pyrolytic graphite is used as the pyrolysis filament, with the major advantage that this material remains inert at high temperatures. The instrument is built within an existing titanium sublimation pump, which simplifies construction and allows for self-pumping of the radical source. Thermal generation of Cl atoms from Cl2 was chosen to test the effectiveness of the instrument. 35Cl and 37Cl were generated with a concomitant decrease in parent 70Cl2 and 72Cl2 species, as monitored by a residual gas analyzer. The cracking fraction of Cl2 as a function of cell temperature is reported, with nearly full conversion achieved at high temperature.
The effect of viewing angle on the spectral behavior of a Gd plasma source near 6.7 nm
Authors: O’Gorman Colm , Otsuka Takamitsu , Yugami Noboru , Jiang Weihua , Endo Akira , Li Bowen , Cummins Thomas , Dunne Padraig , Sokell Emma , O’Sullivan Gerry , Higashiguchi Takeshi
Published: April 2012

We have demonstrated the effect of viewing angle on the extreme ultraviolet (EUV) emission spectra of gadolinium (Gd) near 6.7 nm. The spectra are shown to have a strong dependence on viewing angle when produced with a laser pulse duration of 10 ns, which may be attributed to absorption by low ion stages of Gd and an angular variation in the ion distribution. Absorption effects are less pronounced at a 150-ps pulse duration due to reduced opacity resulting from plasma expansion. Thus for evaluating source intensity, it is necessary to allow for variation with both viewing angle and target orientation.
Geometry and the entropic cost of locally favoured structures in a liquid
Authors: Ronceray Pierre , Harrowell Peter
Published: April 2012

The role of the geometry of locally favoured structures in an equilibrium liquid is analyzed within a recently developed lattice model. The local geometry is shown to influence the liquid through the entropy and the associated density of states. We show that favoured local structures with low symmetry will, generally, incur a low entropy cost and, as a consequence, the liquid will exhibit a substantial accumulation of these low energy environments on cooling prior to the freezing transition.
Influence of a-Si:H deposition power on surface passivation property and thermal stability of a-Si:H/SiNx:H stacks
Authors: Li Hua , Wenham Stuart. R.
Published: April 2012

The effectiveness of hydrogenated amorphous silicon (a-Si:H) layers for passivating crystalline silicon surfaces has been well documented in the literature for well over a decade. One limitation of such layers however has arisen from their inability to withstand temperatures much above their deposition temperature without significant degradation. This limitation is of importance particularly with multicrystalline silicon materials where temperatures of at least 400°C are needed for effective hydrogenation of the crystallographic defects such as grain boundaries. To address this limitation, in this work the surface passivation quality and thermal stability of a stack passivating system, combining a layer of intrinsic a-Si:H and a capping layer of silicon nitride (SiNx:H), on p-type crystalline silicon wafers is studied and optimized. In particular the sensitivity of different microwave (MW) power levels for underlying a-Si:H layer deposition are examined. Both effective minority carrier lifetime (ζeff) measurement and Fourier transform infrared (FTIR) spectrometry were employed to study the bonding configurations, passivating quality and thermal stability of the a-Si:H/SiNx:H stacks. It is established that the higher MW power could result in increased as-deposited ζeff and implied Voc (iVoc) values, indicating likely improved surface passivation quality, but that this combination degrades more quickly when exposed to prolonged thermal treatments. The more dihydride-rich film composition corresponding to the higher MW power appears to be beneficial for bond restructuring by hydrogen interchanges when exposed to short term annealing, however it also appears more susceptible to providing channels for hydrogen out-effusion which is the likely cause of the poorer thermal stability for prolonged high temperature exposure compared with stacks with underlying a-Si:H deposited with lower MW power.
The liveweight gain response of heifers to supplements of molasses or maize while grazing irrigated Leucaena leucocephala/Digitaria eriantha pastures in north-west Australia
Authors: Petty S. R. , Poppi D. P.
Published: April 2012

This experiment in the Ord River Irrigation area (ORIA) of north Western Australia evaluated the liveweight gain of cattle rotationally grazing leucaena (Leucaena leucocephala cv. Cunningham)/pangola (Digitaria eriantha cv. Steudel) pastures alone, or supplemented with four levels of molasses (1.25, 2.50, 3.75, 5.00 kg molasses/head.day, as fed or fresh weight basis) or two levels of cracked maize supplementation (0.75, 1.50 kg/head.day, as fed or fresh weight basis). Seventy Bos indicus cross heifers [~12 months of age, mean initial weight 252 ± 3.8 (s.e.) kg] were allocated to the seven treatments and two replicates of each treatment (five cattle per replicate plus five additional similar heifers) with the stocking rate set at 6.25 head/ha. The experiment was conducted over 106 days of the dry season (August–November). Each replicate paddock of 0.4 ha was rotationally grazed with 10 animals with a 7-day grazing period and a 21-day regrowth period for each rotation.
The mean herbage mass, residual herbage mass and herbage allowance for the experiment were 3.78 t DM/ha, 3.07 t DM/ha and 7.32 kg DM/100 kg liveweight, respectively. Pangola contributed a mean of 0.79 of the herbage mass. There was a significant quadratic response of liveweight gain to level of molasses supplement (P < 0.0087) with an optimum liveweight gain of 1.08 kg/head.day at a supplement level of 2.65 kg molasses/head.day or 8.9 g/kg LW.day derived from the quadratic equation. The quadratic equation was: Liveweight gain = 0.763(±0.0644) + 0.241(±0.0658) * M – 0.046(±0.0126) * M2 (where M is level of molasses supplement kg/head.day). There was no significant response to level of maize supplement. There were no significant differences between treatments in the concentration of rumen ammonia N or volatile fatty acids or in the molar proportion of volatile fatty acids. It was concluded that molasses can be used effectively to increase the liveweight gain of cattle grazing leucaena/pangola pasture at a level of ~8.9 g/kg LW.day.
Good dog! Using livestock guardian dogs to protect livestock from predators in Australia's extensive grazing systems
Authors: van Bommel Linda , Johnson Chris N.
Published: April 2012

Context Wild predators are a serious threat to livestock in Australia. Livestock guardian dogs (LGDs) may be able to reduce or eliminate predation, but their effectiveness in Australian grazing systems has not been systematically evaluated. In particular, little is known about the effectiveness of LGDs in situations where they range freely over large areas in company with large numbers of livestock. Aims We aimed to evaluate the effectiveness of LGDs as currently used in Australia and determine the factors influencing effectiveness, in particular in relation to scale of management. We also documented how LGDs are managed in Australia, evaluated their cost effectiveness, and identified factors that influence the number of dogs required in different property situations. Methods We conducted a telephone survey of 150 livestock producers with LGDs in Australia, including all livestock types and property situations, in all States. Ten producers were visited, of which one is detailed as a case study. Key results Effectiveness was apparently high: 65.7% of respondents reported that predation ceased after obtaining LGDs, and a further 30.2% reported a decrease of predation. When the number of stock per dog exceeds 100, LGDs might not be able to eliminate all predation. Dogs are often kept free-ranging on large properties where wild dogs are the main predator, but are usually restricted in their movements on smaller properties or with smaller predators. The cost of obtaining a LGD is returned within 1–3 years after the dog starts working. The number of dogs required for a property mainly depends on the number of livestock needing protection, and the main type of predator in the area. Conclusions Provided a sufficient number of LGDs are used, they can be as effective in protecting livestock from predators in Australia when ranging freely on large properties with large numbers of livestock as they are in small-scale farming systems. Implications LGDs can provide a cost-effective alternative to conventional predator control methods in Australia’s extensive grazing enterprises, potentially reducing or eliminating the need for other forms of control. LGDs could play a major role in securing the viability of livestock businesses and reconciling people–predator conflict in Australia.
Natural variation in a polyamine transporter determines paraquat tolerance in
Arabidopsis
Authors: Fujita Miki , Fujita Yasunari , Iuchi Satoshi , Yamada Kohji , Kobayashi Yuriko , Urano Kaoru , Kobayashi Masatomo , Yamaguchi-Shinozaki Kazuko , Shinozaki Kazuo
Published: April 2012

Polyamines (PAs) are ubiquitous, polycationic compounds that are essential for the growth and survival of all organisms. Although the PA-uptake system plays a key role in mammalian cancer and in plant survival, the underlying molecular mechanisms are not well understood. Here, we identified an
Arabidopsis
L-type amino acid transporter (LAT) family transporter, named RMV1 (resistant to methyl viologen 1), responsible for uptake of PA and its analog paraquat (PQ). The natural variation in PQ tolerance was determined in 22
Arabidopsis thaliana
accessions based on the polymorphic variation of RMV1. An RMV1-GFP fusion protein localized to the plasma membrane in transformed cells. The
Arabidopsis rmv1
mutant was highly resistant to PQ because of the reduction of PQ uptake activity. Uptake studies indicated that RMV1 mediates proton gradient-driven PQ transport. RMV1 overexpressing plants were hypersensitive to PA and PQ and showed elevated PA/PQ uptake activity, supporting the notion that PQ enters plant cells via a carrier system that inherently functions in PA transport. Furthermore, we demonstrated that polymorphic variation in RMV1 controls PA/PQ uptake activity. Our identification of a molecular entity for PA/PQ uptake and sensitivity provides an important clue for our understanding of the mechanism and biological significance of PA uptake.
Generation and loss of reactive oxygen species in low-temperature atmospheric-pressure RF He + O2 + H2O plasmas
Authors: McKay K , Liu D X , Rong M Z , Iza F , Kong M G
Published: April 2012

This study focuses on the generation and loss of reactive oxygen species (ROS) in low-temperature atmospheric-pressure RF (13.56 MHz) He + O2 + H2O plasmas, which are of interest for many biomedical applications. These plasmas create cocktails of ROS containing ozone, singlet oxygen, atomic oxygen, hydroxyl radicals, hydrogen peroxide and hydroperoxyl radicals, i.e. ROS of great significance as recognized by the free-radical biology community. By means of one-dimensional fluid simulations (61 species, 878 reactions), the key ROS and their generation and loss mechanisms are identified as a function of the oxygen and water content in the feed gas. Identification of the main chemical pathways can guide the optimization of He + O2 + H2O plasmas for the production of particular ROS. It is found that for a given oxygen concentration, the presence of water in the feed gas decreases the net production of oxygen-derived ROS, while for a given water concentration, the presence of oxygen enhances the net production of water-derived ROS. Although most ROS can be generated in a wide range of oxygen and water admixtures, the chemical pathways leading to their generation change significantly as a function of the feed gas composition. Therefore, care must be taken when selecting reduced chemical sets to study these plasmas.
Contributions to the entropy change in melt-spun LaFe11.6Si1.4
Authors: Morrison K , Lyubina J , Moore J D , Caplin A D , Sandeman K G , Gutfleisch O , Cohen L F
Published: April 2012

The full text of this corrigendum is available in the PDF.
Primary Care Training: A Global Perspective
Authors: Watson Jessica , Attridge Madeleine , Begg Soleman
Published: April 2012

Thirty years ago, the Alma-Ata Conference mobilized a ‘primary health care movement’ to tackle health inequalities in all countries. In 2008, the World Health Organisation (WHO) reiterated the need for strong primary care in its report: ‘Primary Health Care — Now More Than Ever’. However, before we can achieve ‘a GP for every person in the world’ ( Heath, 2008 ), we need to have general practice training schemes in every country in the world. Currently, even in Europe, general practice is not recognised as a specialty in every country, and GP training varies considerably. Global differences in GP training are also important to understand given that more than one in three doctors registered in the UK has trained abroad. Examples of poor practice have raised concerns about differences in postgraduate training in different countries. This has led to recent calls from the General Medical Council (GMC) for more support and a basic induction programme for overseas doctors coming to the UK. In this article, we will discuss similarities and differences in GP training globally and discuss opportunities for UK GP trainees to experience primary care training in another country.
Degrees of Reality
Authors: Schebesta Karl , Hüpfl Michael , Rössler Bernhard , Ringl Helmut , Müller Michael P. , Kimberger Oliver
Published: April 2012

Background

Human patient simulators and airway training manikins are widely used to train airway management skills to medical professionals. Furthermore, these patient simulators are employed as standardized "patients" to evaluate airway devices. However, little is known about how realistic these patient simulators and airway-training manikins really are. This trial aimed to evaluate the upper airway anatomy of four high-fidelity patient simulators and two airway trainers in comparison with actual patients by means of radiographic measurements. The volume of the pharyngeal airspace was the primary outcome parameter.

Methods

Computed tomography scans of 20 adult trauma patients without head or neck injuries were compared with computed tomography scans of four high-fidelity patient simulators and two airway trainers. By using 14 predefined distances, two cross-sectional areas and three volume parameters of the upper airway, the manikins' similarity to a human patient was assessed.

Results

The pharyngeal airspace of all manikins differed significantly from the patients' pharyngeal airspace. The HPS Human Patient Simulator (METI®, Sarasota, FL) was the most realistic high-fidelity patient simulator (6/19 [32%] of all parameters were within the 95% CI of human airway measurements).

Conclusion

The airway anatomy of four high-fidelity patient simulators and two airway trainers does not reflect the upper airway anatomy of actual patients. This finding may impact airway training and confound comparative airway device studies.
Revision of Long‐term Gastrostomy
Authors: Siddiqui Mohammad M.F. , Griffiths Mervyn D.
Published: April 2012

Purpose:

Insertion of gastrostomy has become a popular choice for children with feeding problems. With the passage of time, gastrostomies require revision for various reasons. The aims of the present study are to report our experience of the revision of long‐term gastrostomies, to ascertain the reasons for revision, and to discuss any measures that may prevent the need for revision.

Methods:

We conducted a retrospective review of all of the patients requiring gastrostomy revision by the senior author between 2005 and June 2011. The patients had had their original operation in several different hospitals within the United Kingdom, between 1997 and 2008. We excluded those patients requiring the revision for an acute complication (within 1 month) or required revision for subsequent fundoplication. The patients' hospital notes were reviewed to identify the reasons for revision and a literature search was done to find ways to prevent these.

Results:

There were 15 patients who required revision of gastrostomy. Epithelialisation of the gastrostomy track with gastric mucosa was the most common cause (9/15). Other reasons were buried bumper syndrome (BBS) (4/15) and migration of the gastrostomy exit site toward the rib cage (2/15). The mean interval before revision due to the epithelialisation of the tract was 101 months since the insertion of the gastrostomy. The mean for other complications was 26 months for BBS and 95 months for migration of the exit site.

Conclusions:

We believe that the incidence of gastrostomy revision could be reduced. Preventing epithelialisation is difficult and may be minimised by aggressive and generous use of topical silver nitrate. The gastrostomy exit site needs to be as far away from the rib edge as possible. Checking the bumper regularly or use of a gastrostomy balloon button instead of a tube eliminates BBS. Parents need to be aware of the possibility that a long‐term gastrostomy may need surgical revision.
Synchrotron-based dynamic computed tomography of tissue motion for regional lung function measurement
Authors: Dubsky Stephen , Hooper Stuart B. , Siu Karen K. W. , Fouras Andreas
Published: April 2012

During breathing, lung inflation is a dynamic process involving a balance of mechanical factors, including trans-pulmonary pressure gradients, tissue compliance and airway resistance. Current techniques lack the capacity for dynamic measurement of ventilation
in vivo
at sufficient spatial and temporal resolution to allow the spatio-temporal patterns of ventilation to be precisely defined. As a result, little is known of the regional dynamics of lung inflation, in either health or disease. Using fast synchrotron-based imaging (up to 60 frames s
−1
), we have combined dynamic computed tomography (CT) with cross-correlation velocimetry to measure regional time constants and expansion within the mammalian lung
in vivo
. Additionally, our new technique provides estimation of the airflow distribution throughout the bronchial tree during the ventilation cycle. Measurements of lung expansion and airflow in mice and rabbit pups are shown to agree with independent measures. The ability to measure lung function at a regional level will provide invaluable information for studies into normal and pathological lung dynamics, and may provide new pathways for diagnosis of regional lung diseases. Although proof-of-concept data were acquired on a synchrotron, the methodology developed potentially lends itself to clinical CT scanning and therefore offers translational research opportunities.
Characteristics of nucleosomes and linker DNA regions on the genome of the basidiomycete
Mixia osmundae
revealed by mono- and dinucleosome mapping
Authors: Nishida Hiromi , Kondo Shinji , Matsumoto Takashi , Suzuki Yutaka , Yoshikawa Hirofumi , Taylor Todd D. , Sugiyama Junta
Published: April 2012

We present findings on the nucleosomal arrangement in the genome of the basidiomycete
Mixia osmundae
, focusing on nucleosomal linker DNA regions. We have assembled the genomic sequences of
M. osmundae
, annotated genes and transcription start sites (TSSs) on the genome, and created a detailed nucleosome map based on sequencing mono- and dinucleosomal DNA fragments. The nucleosomal DNA length distribution of
M. osmundae
is similar to that of the filamentous ascomycete
Aspergillus fumigatus
, but differs from that of ascomycetous yeasts, strongly suggesting that nucleosome positioning has evolved primarily through neutral drift in fungal species. We found clear association between dinucleotide frequencies and linker DNA regions mapped as the midpoints of dinucleosomes. We also describe a unique pattern found in the nucleosome-depleted region upstream of the TSS observed in the dinucleosome map and the precursor status of dinucleosomes prior to the digestion into mononucleosomes by comparing the mono- and dinucleosome maps. We demonstrate that observation of dinucleosomes as well as of mononucleosomes is valuable in investigating nucleosomal organization of the genome.
Hyperactivation of right inferior frontal cortex in young binge drinkers during response inhibition: a follow‐up study
Authors: López‐Caneda Eduardo , Cadaveira Fernando , Crego Alberto , Gómez‐Suárez Ana , Corral Montserrat , Parada María , Caamaño‐Isorna Francisco , Rodríguez Holguín Socorro
Published: April 2012

Aims  The objective of this study was to examine brain activity, with particular attention to prefrontal function, during response execution and inhibition in youths who have engaged in binge drinking (BD) for at least 2 years.

Design  Event‐related potentials (ERPs) were recorded twice within 3 years, during performance of a Go/NoGo task.

Setting  The study was part of a longitudinal study of the neurocognitive effects of BD.

Participants  A total of 48 undergraduate students, 25 controls (14 females) and 23 binge drinkers (10 females), with no personal or family history of alcoholism or psychopathological disorders.

Measurements  The Go‐P3 and NoGo‐P3 components of the ERPs were examined by principal component analysis and exact low‐resolution tomography analysis (eLORETA).

Findings  Binge drinkers showed larger Go‐P3 amplitudes than controls in the first and second evaluations (P = 0.019). They also showed larger NoGo‐P3 amplitude in the second evaluation (P = 0.002). eLORETA analyses in the second evaluation revealed significantly greater activation of the right inferior frontal cortex (rIFC) in binge drinkers than in controls during successful inhibition (P < 0.05).

Conclusions  Young binge drinkers appear to show abnormal brain activity as measured by event‐related potentials during response execution and inhibition which may represent a neural antecedent of difficulties in impulse control.
Efficacy and agency among poor families with and without children
Authors: Okech David , Howard Waylon J. , Kim Junghyun
Published: April 2012

Families with children and living in poverty are vulnerable to decreased control over their lives and the ability to act in self‐interest. While having children may reduce efficacy among these families, their presence may also, in turn, increase their resilience. Using cross‐sectional data from n= 194 poor families in Southeastern USA, this study compares the constructs of self‐efficacy and agency between families with and without children. Results showed that among families with children, lack of agency was negatively correlated with self‐efficacy Δχ2 (1, n= 194) = 12.65, P < 0.001, r=−0.37. Implications are directed towards practice and policy that may increase the efficacy and agency of poor families with children.
Genotypic variation and selection of traits related to forage yield in tall fescue under irrigated and drought stress environments
Authors: Ebrahimiyan M. , Majidi M. M. , Mirlohi A.
Published: April 2012

Development of a standard evaluation protocol has been a pressing problem for the selection of drought‐resistant genotypes of tall fescue (Festuca arundinacea). This study was conducted to evaluate the association of forage yield with specific phenological and morphological traits to find a proper model for indirect selection under irrigated (normal) and drought‐stress conditions in tall fescue. A random sample of seventy‐five genotypes were clonally propagated and evaluated in normal and drought‐stress environments in the field during 2009 and 2010. Results showed that water stress had a negative effect on forage yield and most of the morphological traits measured and reduced genotypic variation for most of them. Forage yield had the highest genotypic variation, whereas days to pollination had the lowest variation. Low broad‐sense heritability estimates were obtained for dry‐matter yield, but heritability for the traits of number of stems per plant, plant height and crown diameter was moderately high. These traits were identified as the main components of forage yield. The importance of these components and their direct and indirect effects on forage yield was different in normal and drought‐stress conditions. This suggests that indirect selection for developing high‐yielding, drought‐tolerant varieties should be performed under drought‐stress conditions with a specific model.
Protective B‐cell epitopes of Francisella tularensis O‐polysaccharide in a mouse model of respiratory tularaemia
Authors: Lu Zhaohua , Madico Guillermo , Roche Marly I. , Wang Qi , Hui Julia H. , Perkins Hillary M. , Zaia Joseph , Costello Catherine E. , Sharon Jacqueline
Published: April 2012

Antibodies to the lipopolysaccharide (LPS) of Francisella tularensis have been shown to be protective against respiratory tularaemia in mouse models, and we have previously described mouse monoclonal antibodies (mAbs) to non‐overlapping terminal and internal epitopes of the F. tularensis LPS O‐polysaccharide (OAg). In the current study, we used F. tularensis LPS oligosaccharides of defined OAg repeat length as molecular rulers in competition ELISA to demonstrate that the epitope targeted by the terminal OAg‐binding mAb FB11 is contained within one tetrasaccharide repeat whereas the epitope targeted by the internal OAg‐binding mAb Ab52 spans two tetrasaccharide repeats. Both mAbs conferred survival to BALB/c mice infected intranasally with the F. tularensis type B live vaccine strain and prolonged survival of BALB/c mice infected intranasally with the highly virulent F. tularensis type A strain SchuS4. The protective effects correlated with reduced bacterial burden in mAb‐treated infected mice. These results indicate that an oligosaccharide with two OAg tetrasaccharide repeats covers both terminal and internal protective OAg epitopes, which may inform the design of vaccines for tularaemia. Furthermore, the FB11 and Ab52 mAbs could serve as reporters to monitor the response of vaccine recipients to protective B‐cell epitopes of F. tularensis OAg.
Effect of supplementation of wheat flour with resistant starch and monoglycerides in pasta dried at high temperatures
Authors: Vernaza Maria G. , Biasutti Eliza , Schmiele Marcio , Jaekel Leandra Z. , Bannwart Andre , Chang Yoon K.
Published: April 2012

Quality of pastas made from wheat flour (WF) and durum wheat semolina (DWS) with added resistant starch (RS) and distilled monoglyceride was evaluated through a central composite rotational design. A press extruder was used to produce the pasta. Water absorption index showed statistical difference between the WF and DWS indicating that proteins present in each samples were different. Pasta samples obtained with the WF presented a shorter cooking time and less solid loss than those obtained with DWS. Increase in volume and weight gain was similar for both samples. Instrumental texture responses showed that pasta made from DWS had higher values for firmness and springiness and lower for adhesiveness when compare to WF pastas. Nevertheless, pasta made from both samples showed similar behaviours of final RS contents of 4% after cooking. Therefore, they could be considered as a source of fibres according to the Brazilian Laws (3 g dietary fibre/100 g product).
Understanding the influences on self‐confidence among first‐year undergraduate nursing students in Ireland
Authors: Chesser‐Smyth Patricia A. , Long Tony
Published: April 2012

Aim.  To report a mixed‐methods study of the development of self‐confidence in Irish nursing students undertaking the first year of an undergraduate nursing programme.

Background.  Self‐confidence underpins nurses’ competence to carry out care effectively, yet there is little empirical evidence of how this attribute is fostered in pre‐registration preparation. There is an assumption, however, that self‐confidence develops independently and spontaneously.

Design.  A sequential, mixed methods three‐phase design was used.

Method.  The design involved pretest and posttest measurements of self‐confidence, focus group interviews, a student self‐evaluation questionnaire and analysis of the relevant curriculum content. Data were collected between September 2007–April 2008 and sampling was from three cohorts of students at three different Institutes of Technology in Ireland. Data collection matched the nature of the data, including descriptive, non‐inferential statistics and qualitative content analysis.

Results.  There was considerable variation in the amount and nature of theoretical preparation. Factors in clinical practice exerted the most influence. Self‐confidence fluctuated during the first clinical placement and as students’ self‐confidence developed, simultaneously, motivation towards academic achievement increased. Conversely, self‐confidence was quickly eroded by poor preceptor attitudes, lack of communication, and feeling undervalued.

Conclusion.  The development of self‐confidence is complex and multi‐factorial. This study offers further understanding of facilitators and barriers that may be relevant elsewhere in promoting student nurses’ developing self‐confidence. The development of self‐confidence must be recognized as a central tenet for the design and delivery of undergraduate programmes.
A proteomics approach reveals divergent molecular responses to salinity in populations of European whitefish (Coregonus lavaretus)
Authors: PAPAKOSTAS SPIROS , VASEMÄGI ANTI , VÄHÄ JUHA‐PEKKA , HIMBERG MIKAEL , PEIL LAURI , PRIMMER CRAIG R.
Published: April 2012

Osmoregulation is a vital physiological function for fish, as it helps maintain a stable intracellular concentration of ions in environments of variable salinities. We focused on a primarily freshwater species, the European whitefish (Coregonus lavaretus), to investigate the molecular mechanisms underlying salinity tolerance and examine whether these mechanisms differ between genetically similar populations that spawn in freshwater vs. brackishwater environments. A common garden experiment involving 27 families in two populations and five salinity treatments together with a large‐scale, high‐resolution mass spectrometry experiment that quantified 1500 proteins was conducted to assess phenotypic and proteomic responses during early development, from fertilization until hatching, in the studied populations. The populations displayed drastically different phenotypic and proteomic responses to salinity. Freshwater‐spawning whitefish showed a significantly higher mortality rate in higher salinity treatments. Calcium, an ion involved in osmotic stress sensing, had a central role in the observed proteomic responses. Brackishwater‐spawning fish were capable of viable osmoregulation, which was modulated by cortisol, an important seawater‐adaptation hormone in teleost fish. Several proteins were identified to play key roles in osmoregulation, most importantly a highly conserved cytokine, tumour necrosis factor, whereas calcium receptor activities were associated with salinity adaptation. These results imply that individuals from these populations are most likely adapted to their local environments, even though the baseline level of genetic divergence between them is low (FST = 0.049). They also provide clues for choosing candidate loci for studying the molecular basis of salinity adaptation in other species. Further, our approach provides an example of how proteomic methods can be successfully used to obtain novel insights into the molecular mechanisms behind adaptation in non‐model organism.
Scale‐up of TB and HIV programme collaborative activities in Zambia – a 10‐year review
Authors: Kapata N. , Chanda‐Kapata P. , Grobusch M. P. , O’Grady J. , Schwank S. , Bates M. , Jansenn S. , Mwinga A. , Cobelens F. , Mwaba P. , Zumla A.
Published: April 2012

Objective  To review the activities, progress, achievements and challenges of the Zambia Ministry of Health tuberculosis (TB)/HIV collaborative activities over the past decade.

Methods  Analysis of Zambia Ministry of Health National TB and HIV programme documents and external independent programme review reports pertaining to 2000–2010.

Results  The number of people testing for HIV increased from 37 557 persons in 2003 to 1 327 995 persons in 2010 nationally. Those receiving anti‐retroviral therapy (ART) increased from 143 in 2003 to 344 304 in 2010. The national HIV prevalence estimates declined from 14.3% in 2001 to 13.5% in 2009. The proportion of TB patients being tested for HIV increased from 22.6% in 2006 to 84% in 2010 and approximately 70% were HIV positive. The proportion of the HIV‐infected TB patients who: (i) started on ART increased from 38% in 2006 to 50% in 2010; (ii) commenced co‐trimoxazole preventive therapy (CPT) increased from 31% in 2006 to 70% in 2010; and (iii) were successfully treated increased to an average of 80% resulting in decline of deaths from 13% in 2006 to 9% in 2010.

Conclusions  The scale‐up of TB/HIV collaborative programme activities in Zambia has steadily increased over the past decade resulting in increased testing for TB and HIV, and anti‐retroviral (ARV) rollout with improved treatment outcomes among TB patients co‐infected with HIV. Getting service delivery points to adhere to WHO guidelines for collaborative TB/HIV activities remains problematic, especially those meant to reduce the burden of TB in people living with HIV/AIDS (PLWHA).