bluuebunny/crossref_metadata_2025 huggingface dataset:
Electron-emission yield under electron impact of ceramics used as channel materials in Hall-effect thrusters
Authors: Tondu T. , Belhaj M. , Inguimbert V.
Published: November 2011

We report measurement of electron-emission yield (EEY) under the impact of electrons on materials of Hall-effect-thruster (HET) interest: BN, BN–SiO2, and Al2O3. The effects of the material aging (under electron irradiation) on the yield of BN and Al2O3 are investigated. The EEY of BN grows with electron exposure, whereas that of Al2O3 reduces. A simple analysis of our experimental results indicates that these variations are most likely because of surface and near surface composition changes caused by the electron beam. The representativeness of EEY measurements on ceramics that have not suffered from the specific environment of a HET (ion and electron bombardment) is discussed.
A simple merocyanine tandem solar cell with extraordinarily high open-circuit voltage
Authors: Steinmann V. , Kronenberg N. M. , Lenze M. R. , Graf S. M. , Hertel D. , Bürckstümmer H. , Würthner F. , Meerholz K.
Published: November 2011

We present a highly efficient tandem solar cell based on a merocyanine dye, containing two identical subcells connected in series. A recombination layer of Al/MoO3 was used. Due to a substantial improvement of the fill factor, the overall efficiency of the tandem cell was even higher than that of the single-cell reference with identical active layer thickness. By combining the planar heterojunction and the bulk heterojunction concept, efficiencies up to 4.8% were achieved while maintaining a rather simple, fully vacuum-processed device stack consisting of only four organic layers. The optimized open-circuit voltage was as large as 2.1 V.
A high performance thermoacoustic engine
Authors: Tijani M. E. H. , Spoelstra S.
Published: November 2011

In thermoacoustic systems heat is converted into acoustic energy and vice versa. These systems use inert gases as working medium and have no moving parts which makes the thermoacoustic technology a serious alternative to produce mechanical or electrical power, cooling power, and heating in a sustainable and environmentally friendly way. A thermoacoustic Stirling heat engine is designed and built which achieves a record performance of 49% of the Carnot efficiency. The design and performance of the engine is presented. The engine has no moving parts and is made up of few simple components.
Observation and model of an ellipsoidally symmetric velocity space distribution in a weakly-coupled dusty plasma
Authors: Fisher Ross , Thomas Edward
Published: November 2011

The spatially resolved phase space distribution was measured for a dusty plasma system. Analysis of the velocity space component of the distributions revealed that the standard assumption of a spherically symmetric velocity space is not applicable to the observed system. The more general, ellipsoidally symmetric, multi-normal distribution function was applied to model the velocity space and is compared to the canonical spherically symmetric model.
High efficiency coaxial klystron-like relativistic backward wave oscillator with a premodulation cavity
Authors: Xiao Renzhen , Teng Yan , Chen Changhua , Sun Jun
Published: November 2011

The klystron-like relativistic backward wave oscillator (RBWO) combines the transition radiation with Cerenkov radiation and has demonstrated microwave output of high power and high efficiency. The coaxial slow wave structure device can produce microwave with a lower frequency in a smaller cross section. For the purpose of high efficiency, low frequency, and miniaturization, a coaxial klystron-like RBWO with a premodulation cavity is presented. Particle-in-cell simulations show that a microwave with power of 1.15 GW and frequency of 2.1 GHz is generated with conversion efficiency of 48%, whereas for the device with a reflector, the efficiency is 38%.
Dynamics of above-barrier state excitons in multi-stacked quantum dots
Authors: Kojima Osamu , Tobita Naoki , Kita Takashi , Akahane Kouichi
Published: November 2011

We report the relaxation dynamics from above-barrier exciton states to the lowest one in multi-stacked quantum dots (QDs). The photoluminescence decay time increases because of the excitation of higher exciton states, which is attributed to the wider miniband width of above-barrier excitons and the localization of the envelope functions in the barrier layers. The existence of the above barrier minibands makes carrier transport along the growth direction possible and eliminates a difficulty with close QD stacking. These results demonstrate an effective approach to achieve high efficiency QD devices.
Wavelength-dependent frustrated internal reflection via photonic interface states
Authors: Cross G. H. , Brand S.
Published: November 2011

Conventional frustrated internal reflection in which light is able to tunnel across a small air gap between two prisms is a well known phenomenon. In this work, an experimental proof-of-concept demonstration of a polarization and highly wavelength selective version of a similar effect via photonic interface states is given. The photonic interface states are designed to exist within the photonic band gap of Bragg reflectors on the surfaces of the two prisms.
Note: Vibration reduction control of an atomic force microscope using an additional cantilever
Authors: Kim Chulsoo , Jung Jongkyu , Park Kyihwan
Published: November 2011

Since an atomic force microscope is used to measure sub-nanometer level precision, it is sensitive to external vibration. If the vibration can be measured by using an additional sensor, we can obtain the vibration-free signal by subtracting the vibration signal from the signal containing the vibration. To achieve a highly effective vibration rejection ratio, it is important to decide where to locate the additional sensor. This is because the vibration measured at the sensing position should have the same phase as that of the vibration in the signal. Vibration reduction control using this electrical sensing method is verified through time domain analysis and topology images of a standard grid sample.
Communication: Inferring the equation of state of a metastable hard-sphere fluid from the equation of state of a hard-sphere mixture at high densities
Authors: Santos Andrés , Yuste Santos B. , de Haro Mariano López
Published: November 2011

A possible approximate route to obtain the equation of state of the monodisperse hard-sphere system in the metastable fluid region from the knowledge of the equation of state of a hard-sphere mixture at high densities is discussed. The proposal is illustrated by using recent Monte Carlo simulation data for the pressure of a binary mixture. It is further shown to exhibit high internal consistency.
Reproductive performance and fertility in male and female adult mice chronically treated with hexarelin
Authors: Puechagut P. B. , Martini A. C. , Stutz G. , Santillán M. E. , Luque E. M. , Fiol de Cuneo M. , Ruiz R. D. , Vincenti L. M.
Published: November 2011

Hexarelin (HEXr), a synthetic ghrelin analogue, has been associated with modifications of reproductive physiology. In previous studies of adult mice, we detected that HEXr induced significantly reduced ovulation rate and significant correlation coefficients between sexual maturation and corporal weight in offspring. In this study, we investigated the effects of chronic HEXr administration on sperm concentration and functional activity, oestrous cyclicity and pregnancy index, in addition to the number of fetuses and its correlation with the number of corpora lutea. Adult Albino swiss mice were injected (sc) daily with HEXr: 100 μg kg–1 day–1 (HEXr D1) or 200 μg kg–1 day–1 (HEXr D2) for 53 days in males and 30 days in females. We detected a significantly decreased ratio in the number of fetuses per corpora lutea in females treated with HEXr D2 for 30 days before mating and during the first 6 days of pregnancy, in addition to a downward trend in the pregnancy index and percentage of females impregnated by each male treated with both doses of the analogue. Although we did not find any significant effect on additional parameters evaluated in both genders, we propose certain effects of HEXr on the implantation process and/or early development of embryos and over the in vivo reproductive capability of males.
Psychosocial pathways to inconsistent condom use among male sex workers: personality, drug misuse and criminality
Authors: Cortez Fernanda C. Prado , Boer Douglas P. , Baltieri Danilo A.
Published: November 2011

Background This research compared street male sex workers in Santo André, Brazil, that reported consistent condom use with those that revealed inconsistent condom use with their clients, concerning personality aspects, impulsiveness, alcohol and drug consumption, depressive symptoms, sociodemographic data and criminal involvement. Methods: Eighty-six male sex workers were evaluated in face-to-face interviews at their place of work. A ‘snowball’ sampling procedure was used to access this hard-to-reach population. Findings: Male sex workers with inconsistent condom use showed greater involvement with criminal activities, higher reward dependence level and more frequent self-report of being HIV-positive. Conclusions: Conceptualisation of male sex workers’ psychological characteristics may be required where HIV risk is not only attributed to sex work per se, but to other aspects such as personality-related factors and negative identity.
Crystal structure of the GlnZ-DraG complex reveals a different form of PII-target interaction
Authors: Rajendran Chitra , Gerhardt Edileusa C. M. , Bjelic Sasa , Gasperina Antonietta , Scarduelli Marcelo , Pedrosa Fábio O. , Chubatsu Leda S. , Merrick Mike , Souza Emanuel M. , Winkler Fritz K. , Huergo Luciano F. , Li Xiao-Dan
Published: November 2011

Nitrogen metabolism in bacteria and archaea is regulated by a ubiquitous class of proteins belonging to the PIIfamily. PIIproteins act as sensors of cellular nitrogen, carbon, and energy levels, and they control the activities of a wide range of target proteins by protein-protein interaction. The sensing mechanism relies on conformational changes induced by the binding of small molecules to PIIand also by PIIposttranslational modifications. In the diazotrophic bacteriumAzospirillum brasilense, high levels of extracellular ammonium inactivate the nitrogenase regulatory enzyme DraG by relocalizing it from the cytoplasm to the cell membrane. Membrane localization of DraG occurs through the formation of a ternary complex in which the PIIprotein GlnZ interacts simultaneously with DraG and the ammonia channel AmtB. Here we describe the crystal structure of the GlnZ-DraG complex at 2.1 Å resolution, and confirm the physiological relevance of the structural data by site-directed mutagenesis. In contrast to other known PIIcomplexes, the majority of contacts with the target protein do not involve the T-loop region of PII. Hence this structure identifies a different mode of PIIinteraction with a target protein and demonstrates the potential for PIIproteins to interact simultaneously with two different targets. A structural model of the AmtB-GlnZ-DraG ternary complex is presented. The results explain how the intracellular levels of ATP, ADP, and 2-oxoglutarate regulate the interaction between these three proteins and how DraG discriminates GlnZ from its close paralogue GlnB.
Three-dimensional imaging and photostimulation by remote-focusing and holographic light patterning
Authors: Anselmi Francesca , Ventalon Cathie , Bègue Aurélien , Ogden David , Emiliani Valentina
Published: November 2011

Access to three-dimensional structures in the brain is fundamental to probe signal processing at multiple levels, from integration of synaptic inputs to network activity mapping. Here, we present an optical method for independent three-dimensional photoactivation and imaging by combination of digital holography with remote-focusing. We experimentally demonstrate compensation of spherical aberration for out-of-focus imaging in a range of at least 300 μm, as well as scanless imaging along oblique planes. We apply this method to perform functional imaging along tilted dendrites of hippocampal pyramidal neurons in brain slices, after photostimulation by multiple spots glutamate uncaging. By bringing extended portions of tilted dendrites simultaneously in-focus, we monitor the spatial extent of dendritic calcium signals, showing a shift from a widespread to a spatially confined response upon blockage of voltage-gated Na
+
channels.
Direct regulation of nucleosome density by the conserved AAA-ATPase Yta7
Authors: Lombardi Laura M. , Ellahi Aisha , Rine Jasper
Published: November 2011

Yta7 is a highly conserved bromodomain-containing protein with AAA-ATPase homology originally implicated in heterochromatin boundary function in
Saccharomyces cerevisiae
. Although increased activity of the human ortholog has been implicated in malignant breast tumors, Yta7's precise mode of action is unknown. Transcriptional analysis in yeast cells revealed a role for Yta7 and its ATPase function in gene induction, including galactose- and sporulation-induced transcription. This requirement was direct and activating, because Yta7 associated with the
GAL
gene cluster only upon transcriptional induction. Suggestive of a role in transcriptional elongation, Yta7 localized to the ORFs of highly transcribed genes. Intriguingly, the
yta7
Δ mutant's transcriptional defects were partially suppressed by decreased dosage of histones H3 and H4. Consistent with this suppression, cells lacking Yta7 exhibited both increased levels of chromatin-incorporated histone H3 and decreased nucleosome spacing. Importantly, this modulation of H3 levels occurred independently of changes in H3 transcript level. Because Yta7 binds histone H3 in vitro, these results suggested a direct role for Yta7 in H3 eviction or degradation. Further, local loss of Yta7 activity at a long inducible gene resulted in accumulation of H3 at the 3′ end upon transcriptional activation, implying Yta7 may regulate H3 cotranscriptionally.
Plasma polymerization at different positions in an asymmetric ethylene discharge
Authors: Trieschmann Jan , Hegemann Dirk
Published: November 2011

The characteristics of plasma polymerization are investigated in an asymmetric, capacitively coupled plasma discharge. Here, the deposition in different plasma zones, i.e. on the driven electrode, within the plasma bulk and the plasma sheath as well as approximately at the plasma-sheath edge, is investigated. Principal expectations are perfectly met, though new interesting dependences of the obtained a-C : H coatings with respect to film properties and deposition rates are also found. That is, the deposition rates as measured on thin, small glass slides placed directly on the electrode are considerably higher than everywhere else in the plasma, yet only single-sided. In contrast, the deposition rates on the samples within the plasma are lowered depending on the exact placement, while a double-sided coating is obtained. Furthermore, film properties, such as the film density, are highly dependent on the sample placement in the plasma, which can even be higher under floating conditions. With simple physical arguments we are able to show the relations between the deposition rate and the energy input into the plasma as well as between the energy density during film growth and the film density itself.
Electrical modulus analysis on the Ni/CCTO/PVDF system near the percolation threshold
Authors: Yang Wenhu , Yu Shuhui , Sun Rong , Ke Shanming , Huang Haitao , Du Ruxu
Published: November 2011

A type of Ni/CCTO/PVDF three-phase percolative composite was prepared, in which the filler content (volume fraction) of Ni and CCTO was set at 60 vol%. The dependence of permittivity, electrical modulus and ac conductivity on the concentration of Ni and CCTO fillers near the percolation threshold was investigated in detail. The permittivity of the composites dramatically increased as the Ni content approached 24 vol%. This unique physical mechanism was realized as the formation of conductive channels near the percolation threshold. Analysis on the electrical modulus showed that the conductive channels are governed by three relaxation processes induced by the fillers (Ni, CCTO) and PVDF matrix, which are the interfacial polarization derived from the interfaces between fillers (Ni, CCTO) and PVDF matrix, and the polarization of CCTO ceramic filler and PVDF matrix. The conductivity behaviour with various Ni loadings and temperature suggested that the transition from an insulating to a conducting state should be induced by charge tunnelling between Ni–Ni particles, Ni–CCTO fillers and Ni–PVDF matrix. These findings demonstrated that the tunnelling conduction in the composite can be attributed to the unique physical mechanism near the percolation threshold.
Suppression of photo-leakage current in amorphous silicon thin-film transistors by n-doped nanocrystalline silicon
Authors: Lin Hung-Chien , Ho King-Yuan , Hsu Chih-Chieh , Yan Jing-Yi , Ho Jia-Chong
Published: November 2011

The reduction of photo-leakage current of amorphous silicon thin-film transistors (a-Si TFTs) is investigated and is found to be successfully suppressed by the use of an n-doped nanocrystalline silicon layer (n+ nc-Si) as an ohmic contact layer. The shallow-level defects of n+ nc-Si can become trapping centres of photo-induced electrons as the a-Si TFT is operated under light illumination. A lower oxygen concentration during n+ nc-Si deposition can increase the creation of shallow-level defects and improve the contrast ratio of active matrix organic light-emitting diode panels.
Yeast mRNA cap-binding protein Cbc1/Sto1 is necessary for the rapid reprogramming of translation after hyperosmotic shock
Authors: Garre Elena , Romero-Santacreu Lorena , De Clercq Nikki , Blasco-Angulo Nati , Sunnerhagen Per , Alepuz Paula
Published: November 2011

In response to osmotic stress, global translation is inhibited, but the mRNAs encoding stress-protective proteins are selectively translated to allow cell survival. To date, the mechanisms and factors involved in the specific translation of osmostress-responsive genes in Saccharomyces cerevisiae are unknown. We find that the mRNA cap-binding protein Cbc1 is important for yeast survival under osmotic stress. Our results provide new evidence supporting a role of Cbc1 in translation initiation. Cbc1 associates with polysomes, while the deletion of the CBC1 gene causes hypersensitivity to the translation inhibitor cycloheximide and yields synthetic “sickness” in cells with limiting amounts of translation initiator factor eIF4E. In cbc1Δ mutants, translation drops sharply under osmotic stress, the subsequent reinitiation of translation is retarded, and “processing bodies” containing untranslating mRNAs remain for long periods. Furthermore, osmostress-responsive mRNAs are transcriptionally induced after osmotic stress in cbc1Δ cells, but their rapid association with polysomes is delayed. However, in cells containing a thermosensitive eIF4E allele, their inability to grow at 37ºC is suppressed by hyperosmosis, and Cbc1 relocalizes from nucleus to cytoplasm. These data support a model in which eIF4E-translation could be stress-sensitive, while Cbc1-mediated translation is necessary for the rapid translation of osmostress-protective proteins under osmotic stress.
Connecdenn 3/DENND1C binds actin linking Rab35 activation to the actin cytoskeleton
Authors: Marat Andrea L. , Ioannou Maria S. , McPherson Peter S.
Published: November 2011

The small GTPase Rab35 regulates endosomal membrane trafficking but also recruits effectors that modulate actin assembly and organization. Differentially expressed in normal and neoplastic cells (DENN)–domain proteins are a newly identified class of Rab guanine-nucleotide exchange factors (GEFs) that are grouped into eight families, each activating a common Rab. The members of one family, connecdenn 1–3/DENND1A–C, are all GEFs for Rab35. Why Rab35 requires multiple GEFs is unknown. We demonstrate that connecdenn 3 uses a unique C-terminal motif, a feature not found in connecdenn 1 or 2, to directly bind actin. This interaction couples Rab35 activation to the actin cytoskeleton, resulting in dramatic changes in cell shape, notably the formation of protrusive membrane extensions. These alterations are specific to Rab35 activated by connecdenn 3 and require both the actin-binding motif and N-terminal DENN domain, which harbors the GEF activity. It was previously demonstrated that activated Rab35 recruits the actin-bundling protein fascin to actin, but the relevant GEF for this activity was unknown. We demonstrate that connecdenn 3 and Rab35 colocalize with fascin and actin filaments, suggesting that connecdenn 3 is the relevant GEF. Thus, whereas connecdenn 1 and 2 activate Rab35 for endosomal trafficking, connecdenn 3 uniquely activates Rab35 for its role in actin regulation.
Bidding for WIC Infant Formula Contracts: Do Non‐WIC Customers Subsidize WIC Customers?
Authors: Davis David E.
Published: November 2011

Although the Women, Infants, and Children (WIC) food‐assistance program purchases over half of all U.S. infant formula, I find it does not affect wholesale prices. I estimate infant‐formula marginal cost and find it low compared with the wholesale price, implying large price‐cost markups. But I find the program does not affect markups. Instead, the program gives preference to one firm's brand, and that brand attains a prominence in stores that results in larger sales to nonparticipants. The preference is valuable to firms and they bid with rebates to attain exclusive approved status, which results in significant cost savings to the program.
Agricultural Trade and the GATT/WTO: Does Membership Make a Difference?
Authors: Grant Jason H. , Boys Kathryn A.
Published: November 2011

Recent empirical studies have estimated the trade flow effect of membership in the World Trade Organization (WTO) and its predecessor, the General Agreement on Tariffs and Trade (GATT). One important, although largely untested, conclusion from this literature is that the GATT/WTO works well if we ignore trade in agriculture ‐ one of the institutions seemingly apparent failures. This article investigates this conclusion using a large panel of agricultural and non‐agricultural trade flows. The results are impressive: the multilateral institution has delivered significant positive effects on members agricultural trade despite its sensitive nature and the reluctance of members to undertake serious reform. These findings are robust to various slices of the data and recent advances in the specification and estimation of the gravity equation to account for sample selection issues and the extensive margin of trade.
NARWHAL, a primary analysis pipeline for NGS data
Authors: Brouwer R. W. W. , van den Hout M. C. G. N. , Grosveld F. G. , van IJcken W. F. J.
Published: November 2011

Summary: The NARWHAL software pipeline has been developed to automate the primary analysis of Illumina sequencing data. This pipeline combines a new and flexible de-multiplexing tool with open-source aligners and automated quality assessment. The entire pipeline can be run using only one simple sample-sheet for diverse sequencing applications. NARWHAL creates a sample-oriented data structure and outperforms existing tools in speed.

Availability:  https://trac.nbic.nl/narwhal/

Contact: w.vanijcken@erasmusmc.nl

Supplementary information:  Supplementary data are available at Bioinformatics online.
Field Distribution of Wheat Stripe Rust Latent Infection Using Real-Time PCR
Authors: Yan Jiahui , Luo Yong , Chen Tingting , Huang Chong , Ma Zhanhong
Published: November 2011

Stripe rust of wheat, caused by Puccinia striiformis f. tritici, is of worldwide significance. Quantification of latent infection level is critical to estimate the potential for disease epidemics. In this study, field distribution of latent infection and the corresponding observed disease were studied in two growing seasons from 2009 to 2011 in Gangu, Gansu Province and Shangzhuang, Beijing, China. A previously developed real-time polymerase chain reaction (PCR) assay was applied to obtain the molecular disease index (MDX) to quantify the level of latent infection. At 1 to 3 weeks after leaf sampling, the observed disease indices (DX) were assessed in the corresponding experimental sites. The computer software SURFER showed that the spatial distribution patterns of MDX had a linear relationship with DX in field plots with P = 0.01. The aggregation levels of MDX correlated with those of DX in the fields. The disease foci which were correctly detected for latent infections with the real-time PCR for the Gangu and Shangzhuang field plots were 71.4 and 85.7%, respectively. The triadimefon fungicide treatment focused on the detected latent infection foci reduced both the initial inoculum and disease development, resulting in an average reduction in disease area in the field plots of 73 to 81%.
Diversity of murine norovirus in wild-rodent populations: species-specific associations suggest an ancient divergence
Authors: Smith Donald B. , McFadden Nora , Blundell Richard J. , Meredith Anna , Simmonds Peter
Published: November 2011

A survey of wild-rodent populations has revealed that murine norovirus (MNV) is present and diverse in wild-house mice Mus musculus. This virus is genetically similar to MNV infecting show mice and previously described variants circulating in laboratory mice. The detection of MNV in wild-mouse populations suggests that MNV infection of laboratory mice and show mice (from which laboratory mice are derived) derives from contact with or their origins from wild-mouse progenitors. The survey additionally identified frequent infection of wood mice (Apodemus sylvaticus) with genetically divergent variants of MNV. These viruses are distinct from previously described MNV variants, differing by 22–23 % over the complete genome sequence compared with a maximum of 13 % between M. musculus-derived strains. Comparison with other noroviruses reveals that the Apodemus MNV groups with MNV in genogroup V and shares the same overall genome organization, predicted lengths of proteins encoded by ORFs 1–3 and the existence of a conserved alternative reading frame in VP1 encoding a homologue of the MNV ORF4. Different Apodemus MNV isolates were as variable as MNV isolates and showed evidence for inter-isolate recombination. Our observation of species-specific associations of MNV variants in wild populations suggests that murine noroviruses have an ancient origin, a feature that they may share with other norovirus genogroups.
Redox States of Plastids and Mitochondria Differentially Regulate Intercellular Transport via Plasmodesmata
Authors: Stonebloom Solomon , Brunkard Jacob O. , Cheung Alexander C. , Jiang Keni , Feldman Lewis , Zambryski Patricia
Published: November 2011

Recent studies suggest that intercellular transport via plasmodesmata (PD) is regulated by cellular redox state. Until now, this relationship has been unclear, as increased production of reactive oxygen species (ROS) has been associated with both increased and decreased intercellular transport via PD. Here, we show that silencing two genes that both increase transport via PD, INCREASED SIZE EXCLUSION LIMIT1 (ISE1) and ISE2, alters organelle redox state. Using redox-sensitive green fluorescent proteins targeted to the mitochondria or plastids, we show that, relative to wild-type leaves, plastids are more reduced in both ISE1- and ISE2-silenced leaves, whereas mitochondria are more oxidized in ISE1-silenced leaves. We further show that PD transport is positively regulated by ROS production in mitochondria following treatment with salicylhydroxamic acid but negatively regulated by an oxidative shift in both chloroplasts and mitochondria following treatment with paraquat. Thus, oxidative shifts in the mitochondrial redox state positively regulate intercellular transport in leaves, but oxidative shifts in the plastid redox state counteract this effect and negatively regulate intercellular transport. This proposed model reconciles previous contradictory evidence relating ROS production to PD transport and supports accumulating evidence that mitochondria and plastids are crucial regulators of PD function.
Rainfall pattern and nutrient content influences on African elephants’ debarking behaviour in Samburu and Buffalo Springs National Reserves, Kenya
Authors: Ihwagi Festus Wanderi , Chira Robert Mutugi , Kironchi Geoffrey , Vollrath Fritz , Douglas‐Hamilton Iain
Published: November 2011

The magnitude of debarking by elephants was investigated in Samburu and Buffalo Springs National Reserves. About 1617 plants were monitored for debarking intensities for 6 months spanning through dry and wet seasons. Debarking indices ranged from no debarking at all during the wet months to complete stem girding at the height of the dry season. A negative correlation was found between rainfall and debarking indices. It was hypothesized that nutrient content of the bark influenced the magnitude to which trees were debarked. Bark samples were collected from least, moderate and intensely debarked plants throughout the 6 months. These were analysed for calcium (Ca), sodium (Na), phosphorus (P), magnesium (Mg), potassium (K), nitrogen (N), iron (Fe), copper (Cu), manganese (Mn) and zinc (Zn). Significant positive correlations were found between debarking intensity and each of the nutrients N [crude protein (CP)], P, K and Zn. Bark was found to be richest in CP and Calcium. Neutral detergent fibre content was on average 67%. Monthly variations in nutrient composition were minimal. Acacia elatior, the most preferred species had significantly higher quantities of each of the four elements N, P, K and Zn than Acacia tortilis, the second most preferred woody species.
Difficult mask ventilation: does it matter?
Authors: Ramachandran S. K. , Kheterpal S.
Published: November 2011

We discuss the relevance of finding a patient’s lungs difficult to ventilate by facemask during the course of anaesthetic induction. In particular, we discuss the issue of whether it is advisable or unnecessary to check the ability to ventilate by facemask before administering a neuromuscular blocking agent. In the light of advances in supraglottic airway technology it has become possible to insert these devices very soon after induction and in a wider variety of patients. Similarly, the development of videolaryngoscopes and rapidly acting drugs such as rocuronium have raised the possibility of earlier, and possibly more successful, tracheal intubation, with the potential result that mask ventilation becomes redundant. However, we conclude by reaffirming its value in airway management strategies.
Mammalian lipocalin allergens – insights into their enigmatic allergenicity
Authors: Virtanen T. , Kinnunen T. , Rytkönen‐Nissinen M.
Published: November 2011

Most of the important mammal‐derived respiratory allergens, as well as a milk allergen and a few insect allergens, belong to the lipocalin protein family. As mammalian lipocalin allergens are found in dander, saliva and urine, they disperse effectively and are widely present in the indoor environments. Initially, lipocalins were characterized as transport proteins for small, principally hydrophobic molecules, but now they are known to be involved in many other biological functions. Although the amino acid identity between lipocalins is generally at the level of 20–30%, it can be considerably higher. Lipocalin allergens do not exhibit any known physicochemical, functional or structural property that would account for their allergenicity, that is, the capacity to induce T‐helper type 2 immunity against them. A distinctive feature of mammalian lipocalin allergens is their poor capacity to stimulate the cellular arm of the human or murine immune system. Nevertheless, they induce IgE production in a large proportion of atopic individuals exposed to the allergen source. The poor capacity of mammalian lipocalin allergens to stimulate the cellular immune system does not appear to result from the function of regulatory T cells. Instead, the T cell epitopes of mammalian lipocalin allergens are few and those examined have proved to be suboptimal. Moreover, the frequency of mammalian lipocalin allergen‐specific CD4+ T cells is very low in the peripheral blood. Importantly, recent research suggests that the lipocalin allergen‐specific T cell repertoires differ considerably between allergic and healthy subjects. These observations are compatible with our hypothesis that the way CD4+ T‐helper cells recognize the epitopes of mammalian lipocalin allergens may be implicated in their allergenicity. Indeed, as several lipocalins exhibit homologies of 40–60% over species, mammalian lipocalin allergens may be immunologically at the borderline of self and non‐self, which would not allow a strong anti‐allergenic immune response against them.
What’s new in acne? An analysis of systematic reviews and clinically significant trials published in 2010–11
Authors: Simpson R. C. , Grindlay D. J. , Williams H. C.
Published: November 2011

This review summarizes important clinical developments in acne treatment identified in five systematic reviews and two significant primary research studies, published between March 2010 and February 2011. Although evidence showing a direct link between development of bacterial resistance and oral antibiotic therapy for acne is not convincing, prescribers can still tailor their practice to minimize future risks by stopping treatment when appropriate, using benzoyl peroxide, and avoiding combining topical and systemic antimicrobials. A systematic review evaluating combination products containing benzoyl peroxide did not show convincing evidence that such products are superior to monotherapies. A systematic review of combined oral contraceptives confirmed their efficacy for acne in women. However, another systematic review of botanical products for acne failed to provide any good-quality evidence of benefit. A large, well-reported retrospective cohort study attempted to clarify the potential link between isotretinoin and depression/suicide. Although suicide risk peaked 6 months after isotretinoin treatment, an increased risk was present before initiation of isotretinoin, making it difficult to attribute the increased risk to isotretinoin alone. However, those with a history of suicide attempts before treatment made fewer new attempts than those whose behaviour started during treatment. This suggests that patients with severe acne with a history of attempted suicide should not automatically be refused isotretinoin. Another randomized controlled trial of 60 patients from Korea suggested that low-dose isotretinoin dose than might provide a better long-term outcome with minimal side-effects for people with moderate acne.
Inflammatory diseases of the parathyroid gland
Authors: Talat Nadia , Diaz‐Cano Salvador , Schulte Klaus‐Martin
Published: November 2011

Talat N, Diaz‐Cano S & Schulte K‐M (2011) Histopathology59, 897–908 Inflammatory diseases of the parathyroid gland

Aims:  Inflammatory disorders of the parathyroid gland are very rare as compared with those of other endocrine organs. The aim of this study was to provide the first systematic review of this condition.

Methods and results:  A 42‐year‐old patient underwent surgery for recurrent secondary hyperparathyroidism. Histology showed hyperplastic parathyroiditis defined by a mixed inflammatory infiltrate with active germinal centres. Molecular markers revealed significant upregulation of CD68 in an ischaemic background (hypoxia‐inducible factor 1 upregulation) with mitochondrial reaction (malate dehydrogenase 2 upregulation) and hyperparathyroidism (carbonic anhydrase 4 upregulation). Our case demonstrates true intraparathyroid inflammation with terminal B‐cell differentiation. We searched PubMed, ISI Thompson and Google Scholar up to January 2011, using the terms ‘parathyroiditis’, ‘inflammation of parathyroid gland’, ‘lymphocytic infiltrate’, ‘tuberculosis of the parathyroid’, ‘sarcoidosis’, and ‘graulomatous inflammation’. Three autopsy series, 27 articles and 96 case reports with inflammatory parathyroid disorders were identified. Autopsy series showed lymphocytic infiltrates in up to 16% of all cases. The entire material reported lymphocytic infiltrates (n = 69), parathyroiditis with germinal centres (n = 15), sarcoidosis (n = 6), tuberculosis (n = 4), and other granulomatous diseases (n = 2).

Conclusions:  Distinct inflammatory and granulomatous processes in the parathyroid gland are rare. Scanty lymphocytic infiltrates are common, and occur in generalized inflammatory conditions or venous congestion. We note the surprising absence of an association between histological proof of parathyroiditis and hypoparathyroidism.
Interprofessional working or role substitution? A discussion of the emerging roles in emergency care
Authors: Hoskins Rebecca
Published: November 2011

hoskins r. (2011) Interprofessional working or role substitution? A discussion of the emerging roles in emergency care. Journal of Advanced Nursing68(6), 1894–1903.

Aims.  This article presents a discussion of emerging non‐medical roles in emergency care against the current policy context and the issues of role substitution and interprofessional working.

Background.  Non‐medical roles in emergency care have grown internationally in response to an increasing demand for emergency care services and to address the growing importance of the quality healthcare agenda. The blurring of role boundaries between professional groups has become more common.

Data sources.  Searches were made of three electronic databases; CINAHL, Medline and EMBASE. The literature relating to interprofessional healthcare roles, and new roles in emergency care was searched from 1980 to 2010 and underpinned the discussion.

Discussion.  A theoretical framework that has emerged from the literature is that task, role substitution and interprofessional working lie on a spectrum and evolving non‐medical roles can be plotted on the spectrum, usually starting at one end of the spectrum under task substitution and then potentially moving in time towards true interprofessional working.

Conclusions.  There is still a great deal of progress to be made until non‐medical roles in emergency care can truly be encompassed under the umbrella of interprofessional working and that a more robust critical mass of evidence is required to substantiate the theory that interprofessional working within teams contributes to effective, cost‐effective care and better patient outcomes.

Relevance to clinical practice.  It is essential to understand the underlying motivation, policy context and key drivers for the development of new nursing and non‐medical roles. This allows services to be established successfully, by understanding and addressing the key predicable barriers to implementation and change.
AFLP markers reveal high clonal diversity and extreme longevity in four key arctic‐alpine species
Authors: De WITTE LUCIENNE C. , ARMBRUSTER GEORG F. J. , GIELLY LUDOVIC , TABERLET PIERRE , STÖCKLIN JÜRG
Published: November 2011

We investigated clonal diversity, genet size structure and genet longevity in populations of four arctic‐alpine plants (Carex curvula, Dryas octopetala, Salix herbacea and Vaccinium uliginosum) to evaluate their persistence under past climatic oscillations and their potential resistance to future climate change. The size and number of genets were determined by an analysis of amplified fragment length polymorphisms and a standardized sampling design in several European arctic‐alpine populations, where these species are dominant in the vegetation. Genet age was estimated by dividing the size by the annual horizontal size increment from in situ growth measurements. Clonal diversity was generally high but differed among species, and the frequency distribution of genet size was strongly left‐skewed. The largest C. curvula genet had an estimated minimum age of c. 4100 years and a maximum age of c. 5000 years, although 84.8% of the genets in this species were <200 years old. The oldest genets of D. octopetala, S. herbacea and V. uliginosum were found to be at least 500, 450 and 1400 years old, respectively. These results indicate that individuals in the studied populations have survived pronounced climatic oscillations, including the Little Ice Age and the postindustrial warming. The presence of genets in all size classes and the dominance of presumably young individuals suggest repeated recruitment over time, a precondition for adaptation to changing environmental conditions. Together, persistence and continuous genet turnover may ensure maximum ecosystem resilience. Thus, our results indicate that long‐lived clonal plants in arctic‐alpine ecosystems can persist, despite considerable climatic change.
Degradation of seed mucilage by soil microflora promotes early seedling growth of a desert sand dune plant
Authors: YANG XUEJUN , BASKIN CAROL C. , BASKIN JERRY M. , ZHANG WENHAO , HUANG ZHENYING
Published: November 2011

In contrast to the extensive understanding of seed mucilage biosynthesis, much less is known about how mucilage is biodegraded and what role it plays in the soil where seeds germinate. We studied seed mucilage biodegradation by a natural microbial community. High‐performance anion‐exchange chromatography (HPAEC) was used to determine monosaccharide composition in achene mucilage of Artemisia sphaerocephala. Mucilage degradation by the soil microbial community from natural habitats was examined by monosaccharide utilization tests using Biolog plates, chemical assays and phospholipid fatty acid (PLFA) analysis. Glucose (29.4%), mannose (20.3%) and arabinose (19.5%) were found to be the main components of achene mucilage. The mucilage was biodegraded to CO2 and soluble sugars, and an increase in soil microbial biomass was observed during biodegradation. Fluorescence microscopy showed the presence of mucilage (or its derivatives) in seedling tissues after growth with fluorescein isothiocyanate (FITC)‐labelled mucilage. The biodegradation also promoted early seedling growth in barren sand dunes, which was associated with a large soil microbial community that supplies substances promoting seedling establishment. We conclude that biodegradation of seed mucilage can play an ecologically important role in the life cycles of plants especially in harsh desert environments to which A. sphaerocephala is well‐adapted.
Decreased methylation of the NK3 receptor coding gene (TACR3) after cocaine‐induced place preference in marmoset monkeys
Authors: Barros Marilia , Dempster Emma L. , Illott Nicholas , Chabrawi Soha , Maior Rafael S. , Tomaz Carlos , De Souza Silva Maria A. , Huston Joseph P. , Mill Jonathan , Müller Christian P.
Published: November 2011

Epigenetic processes have been implicated in neuronal plasticity following repeated cocaine application. Here we measured DNA methylation at promoter CpG sites of the dopamine transporter (DAT1) and serotonin transporter (SERT) and neurokinin3‐receptor (NK3‐R)‐receptor (TACR3) coding genes in marmoset monkeys after repeated cocaine injections in a conditioned place preference paradigm. We found a decrease in DNA methylation at a specific CpG site in TACR3, but not DAT1 or SERT. Thus, TACR3 is a locus for DNA methylation changes in response to repeated cocaine administration and its establishment as a reinforcer, in support of other evidence implicating the NK3‐R in reinforcement‐ and addiction‐related processes.
Continuous apple consumption induces oral tolerance in birch‐pollen‐associated apple allergy
Authors: Kopac P. , Rudin M. , Gentinetta T. , Gerber R. , Pichler Ch. , Hausmann O. , Schnyder B. , Pichler W. J.
Published: November 2011

To cite this article: Kopac P, Rudin M, Gentinetta T, Gerber R, Pichler C, Hausmann O, Schnyder B, Pichler WJ. Continuous apple consumption induces oral tolerance in birch‐pollen‐associated apple allergy. Allergy 2012; 67: 280–285.

Background:  Patients with birch pollen allergy (major allergen: Bet v 1) have often an associated oral allergy syndrome (OAS) to apple, which contains the cross‐reactive allergen Mal d 1. As successful birch pollen immunotherapy does not consistently improve apple related OAS symptoms, we evaluated whether regular apple consumption has an effect on OAS and immune parameters of Mal d 1 or Bet v 1 allergy.

Methods:  A total of 40 patients with a clear history of birch pollen rhinoconjunctivitis and associated OAS to apple were included in an open, randomized, controlled clinical trial: 27 patients consumed daily defined amount of apple (1–128 g), doubling the amount every two to three weeks, while 13 patients remained untreated. Primary endpoint was the proportion of patients that achieved tolerance to at least 128 g of apple at the end of the study after 8 months. Exploratory endpoints were questionnaire about cross‐reactive food and pollen allergy symptoms, conjunctival provocation test with birch pollen and Bet v 1, and in vitro tests (tIgE, sIgE, and IgG4 to Mal d 1 and Bet v 1; basophil activation test with both allergens).

Results:  Seventeen of 27 patients in active group and none of 13 patients in control group (P = 0.0001) could tolerate a whole apple after the intervention. However, differences in endpoints reflecting systemic immune reactivity did not reach statistical significance.

Conclusion:  In patients with OAS to apple, tolerance can be safely induced with slowly, gradually increasing consumption of apple. However, the observation of a relapse after discounting of apple consumption and absence of immunologic changes suggest that induced tolerance is only transient.
Effects of ethinyl estradiol and desogestrel on clinical and metabolic parameters in Indian patients with polycystic ovary syndrome
Authors: Bhattacharya Sudhindra Mohan , Ghosh Mainak , Basu Ranjan
Published: November 2011

Aim:  The aim of this study was to examine the therapeutic effects of an ethinyl estradiol (EE) and desogestrel (DSG) combination pill in polycystic ovary syndrome (PCOS).

Methods:  A total of 42 women with PCOS were treated with an EE 30 mcg and DSG 150 mcg (EE/DSG) combination pill for 12 cycles. The following parameters were studied at 0, 6, and 12 months: body mass index, abdominal circumference, Ferriman–Gallwey score, presence of acne and acanthosis nigricans, serum testosterone and sex‐hormone‐binding globulin levels, fasting glucose and fasting insulin levels. Free androgen index and glucose : insulin ratio were calculated.

Results:  There were significant improvements in Ferriman–Gallwey score, incidence of acne, serum testosterone and sex‐hormone‐binding globulin levels and free androgen index values at the 6‐month follow up. But there were no further beneficial changes in the above parameters at the 12‐month follow up. There were no significant changes in body mass index, abdominal circumference, incidence of acanthosis nigricans, fasting glucose and insulin levels and glucose : insulin ratio during treatment.

Conclusion:  Significant improvements in hyperandrogenic parameters were seen only in the first 6 months of treatment with EE/DSG in PCOS. Further continuation with this pill did not produce any significant improvement. There were no adverse effects on insulin sensitivity.