bluuebunny/crossref_metadata_2025 huggingface dataset:
Photovoltaic effect of individual polymer nanotube
Authors: Tan Jiahui , Jiang Lang , He Liangfu , Dong Huanli , Hu Wenping
Published: April 2012

Polymer solar cells have attracted world attention due to their great potential for new energy strategy. Solar cells based on bulk heterojunction of conjugated polymers and fullerene derivatives exhibit the best device performance up till today. However, excitons generation and dissociation processes in bulk heterojunction systems remain great challenges. Here, large-area, well-defined nanotubes of regioregular poly(3-hexylthiophene) and fullerene derivative [6,6]-phenyl-C61-butyric acid methyl ester were prepared facilely. And photovoltaic effect of individual nanotube was examined carefully. The high energy conversion efficiency provided tips of understanding excitons generation and dissociation processes at nanometer scale in the bulk heterojunction system.
Tuning magnetic and transport properties through strain engineering in La0.7Sr0.3MnO3/La0.5Sr0.5TiO3 superlattices
Authors: Gu Meng , Song Chengyu , Yang Fan , Arenholz Elke , Browning Nigel D. , Takamura Yayoi
Published: April 2012

Superlattices composed of non-magnetic La0.5Sr0.5TiO3 and ferromagnetic La0.7Sr0.3MnO3 were grown by pulsed laser deposition on various substrates to impose different epitaxial strain states. Well-defined superlattice structures with sharp interfaces were observed using scanning transmission electron microscopy and confirmed by electron energy loss spectroscopy. Defects such as misfit dislocations, partial dislocations, and low-angle grain boundaries were found to partially or fully relax the epitaxial strain while dramatically increasing the magnetic coercive field. Conversely, a large tensile strain was seen to induce a tetragonal distortion in the film lattice and alter the magnetic and magneto-transport properties of the superlattices.
Assessment of the resonance frequency of cantilever carbon nanocones using molecular dynamics simulation
Authors: Firouz-Abadi R. D. , Amini H. , Hosseinian A. R.
Published: April 2012

The resonance frequencies of cantilever carbon nanocones (CNCs) up to 4 nm in height are determined using molecular dynamics simulation based on adaptive intermolecular reactive empirical bond order potential. The frequency content of the free vibrations of CNCs under a lateral initial excitation at the tip is analyzed using fast Fourier transformation, and the resonance frequencies are obtained. The results are reported for various samples to investigate the dependency of the resonance frequency to the geometrical parameters and temperature of CNCs.
Effect of magnetic field on polariton emission characteristics of a quantum-well microcavity diode
Authors: Bhattacharya Pallab , Das Ayan , Bhowmick Sishir , Jankowski Marc , Lee Chi-sen
Published: April 2012

The effect of an applied magnetic field on the polariton emission characteristics of a In0.1Ga0.9As/GaAs multi-quantum well microcavity diode in the strong coupling regime has been investigated. It is observed that the relaxation bottleneck is suppressed due to an enhancement of the polariton-phonon scattering rates in the presence of the magnetic field. A distinct non-linearity is also observed in the light-current characteristics.
Narrow-band long-/very-long wavelength two-color type-II InAs/GaSb superlattice photodetector by changing the bias polarity
Authors: Zhang Yanhua , Ma Wenquan , Wei Yang , Cao Yulian , Huang Jianliang , Cui Kai , Guo Xiaolu
Published: April 2012

We report on a narrow-band two-color photodetector using type-II InAs/GaSb superlattices (SLs) in the long-/very-long wavelength infrared (VLWIR) ranges by changing the polarity of the bias. The narrow-band photoresponse is achieved by sequentially growing the doped SL structure that has a shorter cutoff wavelength as a low-pass filter for the absorption layers that has a longer cutoff wavelength. At 77 K, the 50% cutoff wavelength of the photodiode is 10 μm when the applied bias voltage is –0.1 V and is 16 μm at +40 mV. The δλ/λ is 44% for the LWIR band and is 46% for the VLWIR band.
Photo-inducible cell ablation in
Caenorhabditis elegans
using the genetically encoded singlet oxygen generating protein miniSOG
Authors: Qi Yingchuan B. , Garren Emma J. , Shu Xiaokun , Tsien Roger Y. , Jin Yishi
Published: April 2012

We describe a method for light-inducible and tissue-selective cell ablation using a genetically encoded photosensitizer, miniSOG (mini singlet oxygen generator). miniSOG is a newly engineered fluorescent protein of 106 amino acids that generates singlet oxygen in quantum yield upon blue-light illumination. We transgenically expressed mitochondrially targeted miniSOG (mito-miniSOG) in
Caenorhabditis elegans
neurons. Upon blue-light illumination, mito-miniSOG causes rapid and effective death of neurons in a cell-autonomous manner without detectable damages to surrounding tissues. Neuronal death induced by mito-miniSOG appears to be independent of the caspase CED-3, but the clearance of the damaged cells partially depends on the phagocytic receptor CED-1, a homolog of human CD91. We show that neurons can be killed at different developmental stages. We further use this method to investigate the role of the premotor interneurons in regulating the convulsive behavior caused by a gain-of-function mutation in the neuronal acetylcholine receptor
acr-2.
Our findings support an instructive role for the interneuron AVB in controlling motor neuron activity and reveal an inhibitory effect of the backward premotor interneurons on the forward interneurons. In summary, the simple inducible cell ablation method reported here allows temporal and spatial control and will prove to be a useful tool in studying the function of specific cells within complex cellular contexts.
Influences of Hatchery Supplementation, Spawner Distribution, and Habitat on Genetic Structure of Chinook Salmon in the South Fork Salmon River, Idaho
Authors: Matala Andrew P. , Narum Shawn R. , Young William , Vogel Jason L.
Published: April 2012

We evaluated the genetic influence of hatchery supplementation on distinct naturally spawning populations of Chinook salmon Oncorhynchus tshawytscha in the South Fork Salmon River (SFSR), Idaho. Genetic tissue samples were collected from unmarked natural-origin and McCall Fish Hatchery (MFH)-reared Chinook salmon carcasses, and fish were identified by an adipose fin clip at five main-stem sites located both upstream and downstream of a seasonal exclusionary weir in the upper SFSR. We evaluated allele frequency data across 95 single-nucleotide polymorphism loci to determine the extent of genetic differentiation among collections. Genetic distance analyses and homogeneity tests indicated little subpopulation distinction in the upper SFSR. The weak overall genetic structure (global F  ST = 0.010) is likely reflective of a population diversity similar to the historical structure with introgression by MFH stock in the naturally spawning population of the upper SFSR. Further analyses were conducted to evaluate the genetic structure among the upper SFSR and spawning aggregates in two adjacent SFSR tributaries: the Secesh River, which is devoid of any hatchery stocking, and Johnson Creek, where a discrete supplementation program has been implemented using only Johnson Creek fish. Our results indicated variable abundances of SFSR hatchery spawners distributed spatially among the three main watersheds. Gene flow appears to be restricted and genetic differentiation to be relatively large despite substantial hatchery releases in the upper SFSR. Three historical aggregates of Chinook salmon appear to persist in the SFSR metapopulation, where variable hatchery influences are coincident with the distribution of suitable spawning habitat and watershed-specific management objectives.

Received January 5, 2011; accepted December 12, 2011
Effects of Shading on the Reproductive Output and Embryo Viability of Gulf Killifish
Authors: Gothreaux C T , Green C C
Published: April 2012

Gulf killifish Fundulus grandis broodstock (7.3 ± 0.2 g [mean ± SE]) were held in static outdoor tanks at a 4:1 (female : male) sex ratio and a density of 20 fish/m3. Shade cloth was used to cover 0, 40, or 80% of the surface area of 12 randomly selected outdoor tanks. Eggs were collected from all tanks twice per week by using spawning mats suspended 15 cm below the water surface. Collected eggs were measured volumetrically and assessed for total number and embryo viability. The use of shade cloth had a significant effect on water temperature, the number of eggs collected, and embryo viability. Specifically, shading affected mean weekly water temperature, and the 80% treatment had significantly lower temperatures than both the 0% and 40% treatments during the months of June through August and than the 0% treatment in September. There was a clear cyclical reproductive pattern across all treatments, in which peaks in egg production occurred between the full and new moon phases for the majority of collection dates. Significant differences in the mean number of eggs collected among shade cloth treatments were present only for the month of September, when the 80% treatment produced significantly fewer eggs. The proportion of viable embryos was significantly higher for the 80% treatment than for the other treatments for the months of June, July, and August. The use of shade cloth during the summer months can increase the number of viable embryos produced during the summer depression of the protracted, bimodal spawning season of cultured Gulf killifish.
Primary and Secondary Responses of Juveniles of a Teleostean, Pikeperch Sander lucioperca, and a Chondrostean, Persian Sturgeon Acipenser persicus, to Handling during Transport
Authors: Falahatkar Bahram , Akhavan Sobhan R , Efatpanah Iraj , Meknatkhah Bahman
Published: April 2012

The dynamics of stress responses in small, juvenile pikeperch Sander lucioperca (as a representative teleostean) and small, juvenile Persian sturgeon Acipenser persicus (as a chondrostean) were determined during capture and transportation for release into rivers. Blood samples were obtained from juveniles from a pond, channel, and loading basin and at 1.5 and 24 h after loading. Samples were analyzed for cortisol, glucose, and lactate concentrations, and mortality was recorded. Plasma cortisol concentrations increased, reaching a maximum in Persian sturgeon from the channel and pikeperch from the loading basin. Significant increases in plasma glucose concentrations were observed in samples from the channel and at 1.5 h after loading for Persian sturgeon and pikeperch, respectively. Similarly, significant decreases in lactate concentrations were observed 1.5 h after loading in both species. The results of this study show the sensitivity of these species to stress during transportation. They suggest a higher resistance to transportation stress by the sturgeon than the pikeperch, but it is highly recommended that transportation procedures and capture techniques be modified so that they are appropriate for the species.
Morphological processing during visual word recognition in developing readers: Evidence from masked priming
Authors: Beyersmann Elisabeth , Castles Anne , Coltheart Max
Published: April 2012

Masked priming studies with adult readers have provided evidence for a form-based morpho-orthographic segmentation mechanism that “blindly” decomposes any word with the appearance of morphological complexity. The present studies investigated whether evidence for structural morphological decomposition can be obtained with developing readers. We used a masked primed lexical decision design first adopted by Rastle, Davis, and New (2004), comparing truly suffixed ( golden–GOLD) and pseudosuffixed ( mother–MOTH) prime–target pairs with nonsuffixed controls ( spinach–SPIN). Experiment 1 tested adult readers, showing that priming from both pseudo- and truly suffixed primes could be obtained using our own set of high-frequency word materials. Experiment 2 assessed a group of Year 3 and Year 5 children, but priming only occurred when prime and target shared a true morphological relationship, and not when the relationship was pseudomorphological. This pattern of results indicates that morpho-orthographic decomposition mechanisms do not become automatized until a relatively late stage in reading development.
Spatial interference between gaze direction and gaze location: A study on the eye contact effect
Authors: Cañadas Elena , Lupiáñez Juan
Published: April 2012

Perceived gaze in faces is an important social cue that influences spatial orienting of attention. In three experiments, we examined whether the social relevance of gaze direction modulated spatial interference in response selection, using three different stimuli: faces, isolated eyes, and symbolic eyes (Experiments 1, 2, and 3, respectively). Each experiment employed a variant of the spatial Stroop paradigm in which face location and gaze direction were put into conflict. Results showed a reverse congruency effect between face location to the right or left of fixation and gaze direction only for stimuli with a social meaning to participants (Experiments 1 and 2). The opposite was observed for the nonsocial stimuli used in Experiment 3. Results are explained as facilitation in response to eye contact.
Tachyon search speeds up retrieval of similar sequences by several orders of magnitude
Authors: Tan Joshua , Kuchibhatla Durga , Sirota Fernanda L. , Sherman Westley A. , Gattermayer Tobias , Kwoh Chia Yee , Eisenhaber Frank , Schneider Georg , Maurer-Stroh Sebastian
Published: April 2012

Summary: The usage of current sequence search tools becomes increasingly slower as databases of protein sequences continue to grow exponentially. Tachyon, a new algorithm that identifies closely related protein sequences ~200 times faster than standard BLAST, circumvents this limitation with a reduced database and oligopeptide matching heuristic.

Availability and implementation: The tool is publicly accessible as a webserver at http://tachyon.bii.a-star.edu.sg and can also be accessed programmatically through SOAP.

Contact:  sebastianms@bii.a-star.edu.sg

Supplementary information:  Supplementary data are available at the Bioinformatics online.
Long-term familiarity promotes joining in neighbour nest defence
Authors: Grabowska-Zhang A. M. , Sheldon B. C. , Hinde C. A.
Published: April 2012

Familiarity plays an important role in the evolution of sociality and cooperation. Familiar individuals may gain a reputation for participating in, or defecting from, cooperative tasks. Previous research suggests that long-term familiarity with territorial neighbours benefits breeders. We tested the hypothesis that great tits (Parus major) are more likely to join in neighbours' nest defence if those neighbours are familiar from the previous year. We show that neighbours that shared a territory boundary the previous year are more likely to join their neighbours' nest defence than neighbours that did not share a boundary before. Closer neighbours did not differ from distant neighbours in their latency to join. For familiar neighbours that joined, there was no difference in call rate in relation to whether one or both members of the focal pair were familiar. First-time breeders (by definition unfamiliar) did not join each other's nest defence. This is the first evidence of a relationship between familiarity and joining in nest defence. Such direct benefits of familiarity may have important implications in the evolution of sociality.
Common structure in the heterogeneity of plant-matter decay
Authors: Forney David C. , Rothman Daniel H.
Published: April 2012

Carbon removed from the atmosphere by photosynthesis is released back by respiration. Although some organic carbon is degraded quickly, older carbon persists; consequently carbon stocks are much larger than predicted by initial decomposition rates. This disparity can be traced to a wide range of first-order decay-rate constants, but the rate distributions and the mechanisms that determine them are unknown. Here, we pose and solve an inverse problem to find the rate distributions corresponding to the decomposition of plant matter throughout North America. We find that rate distributions are lognormal, with a mean and variance that depend on climatic conditions and substrate. Changes in temperature and precipitation scale all rates similarly, whereas the initial substrate composition sets the time scale of faster rates. These findings probably result from the interplay of stochastic processes and biochemical kinetics, suggesting that the intrinsic variability of decomposers, substrate and environment results in a predictable distribution of rates. Within this framework, turnover times increase exponentially with the kinetic heterogeneity of rates, thereby providing a theoretical expression for the persistence of recalcitrant organic carbon in the natural environment.
Suitability of European climate for the Asian tiger mosquito
Aedes albopictus
: recent trends and future scenarios
Authors: Caminade Cyril , Medlock Jolyon M. , Ducheyne Els , McIntyre K. Marie , Leach Steve , Baylis Matthew , Morse Andrew P.
Published: April 2012

The Asian tiger mosquito (
Aedes albopictus
) is an invasive species that has the potential to transmit infectious diseases such as dengue and chikungunya fever. Using high-resolution observations and regional climate model scenarios for the future, we investigated the suitability of Europe for
A. albopictus
using both recent climate and future climate conditions. The results show that southern France, northern Italy, the northern coast of Spain, the eastern coast of the Adriatic Sea and western Turkey were climatically suitable areas for the establishment of the mosquito during the 1960–1980s. Over the last two decades, climate conditions have become more suitable for the mosquito over central northwestern Europe (Benelux, western Germany) and the Balkans, while they have become less suitable over southern Spain. Similar trends are likely in the future, with an increased risk simulated over northern Europe and slightly decreased risk over southern Europe. These distribution shifts are related to wetter and warmer conditions favouring the overwintering of
A. albopictus
in the north, and drier and warmer summers that might limit its southward expansion.
Evolution of crack-bridging and crack-tip driving force during the growth of a fatigue crack in a Ti/SiC composite
Authors: Withers Philip J. , Lopez-Crespo Pablo , Kyrieleis Albrecht , Hung Yu-Chen
Published: April 2012

High spatial resolution diffraction and imaging using synchrotron X-rays are combined to monitor the incremental growth of a fatigue crack through the matrix of a Ti-6Al-4V/SCS-6 SiC monofilament metal matrix composite. X-ray tomography is used to quantify the crack opening displacement (COD) and diffraction to measure the crack-tip stress field in each phase, the wear degraded interfacial strengths, as well as the crack face tractions applied by the bridging fibres, at maximum () and minimum () loading as a function of crack length. In this way, it has been possible to quantify the crack-tip driving force (the stress intensity range effective at the crack-tip) in three ways: from the COD, the bridging stresses and the crack-tip stress field. The fibre stresses act to prop open the crack atand shield the crack atsuch that the change in COD is small over the fatigue cycle. Consequently, the effective stress intensity range at the crack tip remains around 10 MPa√m as the crack lengthens, as more and more fibres bridge the crack despite the normally applied stress intensity rising to 60 MPa√m. The implications of the derived fracture mechanics parameters are assessed and the wider potential of X-ray diffraction and imaging for crack-tip microscopy is discussed.
Evidence of correlated evolution of hypsodonty and exceptional longevity in endemic insular mammals
Authors: Jordana Xavier , Marín-Moratalla Nekane , DeMiguel Daniel , Kaiser Thomas M. , Köhler Meike
Published: April 2012

Here, we test whether the increase in tooth height in insular endemics results from the expansion of the dietary niche under resource limitation, as widely considered, or whether it represents an investment in dental durability in response to the selection for extended longevity under low levels of extrinsic mortality. We tested these hypotheses in the extremely hypsodont fossil bovid
Myotragus balearicus
from the Balearic Islands, an ideal model to study the evolutionary trends on islands. Dental abrasion was significantly lower in the insular bovid than in highly hypsodont continental artiodactyls, suggesting that feeding habits are not the sole driving force behind increased crown height. However, the estimated longevity for
M. balearicus
based on dental durability was two times that predicted from body mass. Survivorship curves confirm that an extraordinarily large number of individuals approached the longevity of the species. Our results, hence, provide evidence that hypsodonty in insular endemics is the outcome of selection for increased durability of the permanent dentition in association with an extended lifespan. In the context of insularity, our results lend additional support to the disposable soma theory of ageing confirming the dependency of somatic maintenance and repair on lifespan, and its control by resource availability and extrinsic mortality.
Variation in Nectar Volume and Sugar Concentration ofAllium ursinumL. ssp.ucrainicumin Three Habitats
Authors: Farkas Ágnes , Molnár Réka , Morschhauser Tamás , Hahn István
Published: April 2012

Floral nectar volume and concentration of ramson (Allium ursinumL. ssp.ucrainicum) were investigated in three different habitats, including two types of sessile oak-hornbeam association on brown forest soil with clay illuviation and a silver lime-flowering ash rock forest association on rendzina. Daily nectar production ranged from 0.1 to 3.8 μL per flower with sugar concentrations of 25 to 50%. Mean nectar volumes and concentrations showed significant differences between freely exposed flowers and covered flowers, which had been isolated from flower visitors 24 h prior to nectar studies. Both the amount and quality of nectar were affected by microclimatic conditions and soil properties and varied between populations at different habitats. In the silver lime-flowering ash rock-forest association mean nectar volumes and concentrations were lower than in a typical sessile oak-hornbeam association on three occasions, the difference being significant in two cases. During full bloom, the date of sampling did not have a profound effect on either nectar volume or concentration.
Tuberculous Meningitis in Adults: A Review of 160 Cases
Authors: Pehlivanoglu Filiz , Kart Yasar Kadriye , Sengoz Gonul
Published: April 2012

Objective. This study aimed to evaluate epidemiological, clinical, laboratory, and neuroimaging features of 160 adult patients with tuberculous meningitis (TBM) according to “Thwaites’ diagnostic index.”Methods. The subjects of this retrospective study are the patients with TBM who were followed up between years 1998 and 2009 in a tertiary referral hospital. Diagnosis of TBM was based on clinical, laboratory, and neuroimaging signs and Thwaites’ diagnostic index.Results.Mycobacterium tuberculosiswas isolated from CSF in 59 of 148 patients. Seventeen percent of the patients died, 71% recovered completely, and 13% recovered with neurological sequel at the end of the sixth month.Conclusions. Despite new developments in laboratory or neuroimaging techniques, the diagnosis of TBM is still based on clinical features with the help of laboratory. Early diagnosis by suspecting TBM may prevent therapy delay and may result in decrease in the mortality and morbidity.
Angiotensins Inhibit Cell Growth in GH3 Lactosomatotroph Pituitary Tumor Cell Culture: A Possible Involvement of the p44/42 and p38 MAPK Pathways
Authors: Ptasinska-Wnuk Dorota , Lawnicka Hanna , Mucha Slawomir , Kunert-Radek Jolanta , Pawlikowski Marek , Stepien Henryk
Published: April 2012

The local renin-angiotensin system is present in the pituitary. We investigated the effects of angiotensins on GH3 lactosomatotroph cells proliferation in vitro and the involvement of p44/42 and p38 MAPK inhibitors in the growth-regulatory effects of angiotensins.Materials and Methods. Cell viability using the Mosmann method and proliferation by the measurement of BrdU incorporation during DNA synthesis were estimated.Results. Ang II and ang IV decreased the viability and proliferation of GH3 cells. Inhibitor of p44/42 MAPK attenuated the effects of ang II on cell viability and proliferation but did not affect the ang 5-8-dependent actions. Inhibitor of p38 MAPK prevented the decrease in the number of GH3 cells in ang-II- and ang-IV-treated groups.Conclusions. The growth-inhibitory effect of ang II is possibly mediated by the p44/42 MAPK. The p38 MAPK appears to mediate the inhibitory effects of both ang II and ang 5–8 upon cell survival.
catena-Poly[[[(oxamide dioxime-κ2N,N′)copper(II)]-μ-L-tartrato-κ4O1,O2:O3,O4] tetrahydrate]: a chiral nanochannel framework hosting solvent water molecules
Authors: Bélombé Michel M. , Nenwa Justin , Wankap Kouamo Jean S. T. , Ponou Siméon , Fischer Andreas
Published: April 2012

The crystal structure of the title compound, {[Cu(C4H4O6)(C2H6N4O2)]·4H2O}n, contains the central CuIIcation in a distorted octahedral coordination, symmetrically chelated by the two imine N atoms of a neutral oxamide dioxime (H2oxado) ligand [Cu—N = 1.9829 (16) Å] and unsymmetrically bis-chelated by two halves of the L-(+)-tartrate(2−) (tart) ligands, each half being linked to the CuIIcationviathe deprotonated carboxylate group and protonated hydroxy group [Cu—O = 1.9356 (14) and 2.4674 (13) Å, respectively]. The extended asymmetric unit is defined by twofold axes, one passing through the CuIIcation and the centre of the oxamide dioxime (H2oxado) ligand and the another two (symmetry related) bisecting the central C—C bonds of the tartrate ions. The structure is chiral, consisting of enantiomeric linear-chain polymers oriented along [001], with virtual monomeric {Cu(tart0.5)2(H2oxado)} repeat units and with the chains interleaved face-to-face into `twin pillars'. Nanochannels exist, running parallel to thecaxis and bisectingaandb, which host `double strings' of solvent water molecules. Extensive hydrogen bonding (O—H...O and N—H...O) between the chains and solvent water molecules, together with extended π–σ interactions, consolidate the bulk crystal structure.
2-Amino-6-methoxy-4-(4-methylanilino)-5-nitrosopyrimidine and ethylN-[4-(adamantan-1-ylamino)-2-amino-5-nitrosopyrimidin-6-yl]-3-aminopropionate: polarized electronic structures and hydrogen-bonded supramolecular assembly in one and two dimensions
Authors: Yépes Andrés F. , Palma Alirio , Marchal Antonio , Cobo Justo , Glidewell Christopher
Published: April 2012

In both 2-amino-6-methoxy-4-(4-methylanilino)-5-nitrosopyrimidine, C12H13N5O2, (I), and ethylN-[4-(1-adamantylamino)-2-amino-5-nitrosopyrimidin-6-yl]-3-aminopropionate, C19H28N6O3, (II), the nitrosopyrimidine unit is planar and the bond distances provide evidence for significant polarization of the electronic structures. In (II), the ethoxycarbonyl fragment of the molecule is disordered over two sets of sites with occupancies of 0.910 (4) and 0.090 (4). In the molecules of both compounds, there is an intramolecular N—H...O hydrogen bond. The molecules of (I) are linked into a chain of rings by a combination of N—H...O and C—H...O hydrogen bonds, while the molecules of (II) are linked by a two-centre N—H...N hydrogen bond and a three-centre N—H...(N,O) hydrogen bond to form sheets containing four distinct types of ring.
Meta‐analysis: probiotics in antibiotic‐associated diarrhoea
Authors: Videlock E. J. , Cremonini F.
Published: April 2012

Background

Diarrhoea is a common occurrence in association with antibiotic administration. Earlier studies and meta‐analyses have suggested that probiotic administration reduces the incidence of antibiotic‐associated diarrhoea (AAD).

Aim

To estimate the reduction in risk of AAD with administration of probiotics in randomised placebo‐controlled trials and to identify factors associated with such reduction.

Methods

Meta‐analysis of randomised, double‐blinded, placebo‐controlled trials including patients treated with antibiotics and administered a probiotic for at least the duration of the antibiotic treatment. The outcome was incidence of diarrhoea irrespective of the presence of
C

lostridium difficile or the development of pseudomembranous colitis. Meta‐analysis and meta‐regression methods were used to synthesise data and to assess influence of: mean age, duration of antibiotics, risk of bias and incidence of diarrhoea in the placebo group on outcomes. Subgroup analyses explored effects of different probiotic species, patient populations and treatment indications.

Results

A total of 34 studies were included with 4138 patients. The pooled relative risk (RR) for AAD in the probiotic group vs. placebo was 0.53 (95% CI 0.44–0.63), corresponding to a number needed to treat (NNT) of 8 (95% CI 7–11). The preventive effect of probiotics remained significant when grouped by probiotic species, population age group, relative duration of antibiotics and probiotics, study risk of bias and probiotic administered. The pooled RR for AAD during treatment for
H

elicobacter pylori (H. pylori) was 0.37 (95% CI 0.20–0.69), corresponding to a NNT of 5 (95% CI 4–10).

Conclusions

This updated meta‐analysis confirms earlier results supporting the preventive effects of probiotics in AAD.
Long‐term, open‐label trial: safety and efficacy of continuous maintenance treatment with pantoprazole for up to 15 years in severe acid‐peptic disease
Authors: Brunner G. , Athmann C. , Schneider A.
Published: April 2012

Background

To date, the safety and tolerability of proton pump inhibitors (PPIs) have been demonstrated in studies of up to 10 years.

Aim

To report on the tolerability, safety and efficacy of up to 15 years' continuous treatment with pantoprazole in patients with severe acid‐peptic disease.

Methods

Following healing of endoscopically confirmed peptic ulcer or reflux oesophagitis during 4–12 weeks' treatment with pantoprazole (40–80 mg/day), adult patients received open‐label maintenance treatment with pantoprazole (40–160 mg/day) for up to 15 years in a single centre combined study (10‐year initial study; 5‐year extension study). Safety assessments were carried out using endoscopy, clinical examination, clinical laboratory investigations, serum gastrin determination, gastric mucosal histology and mucosal endocrine cell quantification.

Results

The safety set comprised 142 patients. At 12 weeks, healing rates were 95.8%. During long‐term treatment, mean fasting gastrin levels rose from baseline to moderate levels throughout the study. Mean enterochromaffin‐like cell density showed a moderate initial increase during the first 3 years, remaining stable thereafter. These changes were not associated with any clinically relevant changes of the gastric mucosa. Patients with successful Helicobacter pylori eradication showed long‐term regression of antral and corpus gastritis during continued pantoprazole treatment.

Conclusions

Daily pantoprazole maintenance therapy for up to 15 years for severe acid‐peptic disease is effective and well tolerated, with no identified safety concerns. The longest study to date, these data provide reassuring evidence for the long‐term safety of pantoprazole.
Implications of PNPLA3 polymorphism in chronic hepatitis C patients receiving peginterferon plus ribavirin
Authors: Valenti L. , Aghemo A. , Stättermayer A. F. , Maggioni P. , De Nicola S. , Motta B. M. , Rumi M. G. , Dongiovanni P. , Ferenci P. , Colombo M. , Fargion S.
Published: April 2012

Background

Homozygosity for the PNPLA3 p.I148M polymorphism influences steatosis and fibrogenesis in chronic hepatitis C (CHC).

Aim

To evaluate the effect of p.148M/M on sustained virological response (SVR) and viral kinetics in patients who underwent antiviral therapy with peg‐interferon and ribavirin, stratified according to viral genotype and fibrosis severity, and secondarily, the interaction with interleukin‐28B
(
IL28B
) genotype on liver damage.

Methods

In this observational study, we considered 602 treatment‐naïve consecutive patients from tertiary referral centres in Milan and Vienna [61% genotype 1 (G1), 30% advanced fibrosis, 33%
IL28B
rs12979860 CC].

Results

The p.148M/M genotype, detected in 8% of patients, did not influence SVR in the overall series (P = 0.29), but it was associated with SVR (3/17, 17% vs. 56/121, 46%; P = 0.034) and complete early viral response (4/17, 23% vs. 68/121, 56%; P = 0.018) in G1/4 patients with advanced fibrosis. After adjustment for age, viral load,
IL28B
CC genotype, treatment dose, and steatosis, p.148M/M remained a predictor of SVR in G1/4 patients with advanced fibrosis (OR 0.23, 95% CI 0.04–0.87). The p.148M/M genotype was associated with more advanced fibrosis in the overall series (P = 0.049), whereas the rs12979860
IL28B
CC genotype only in patients negative for p.148M/M (P = 0.017), independently of age, BMI and alanine transaminase levels (OR 1.51, 95% CI 1.01–2.27).

Conclusions

PNPLA3
p.148M/M genotype was negatively associated with SVR and early viral kinetics independently of steatosis, albeit only in difficult‐to‐cure G1/4 patients with advanced fibrosis, whereas stratification for the p.148M/M

PNPLA3
genotype unmasked an association between
IL28B
CC genotype and more severe liver fibrosis.
Comparison of the effectiveness of two protocols for vaccination (standard and double dosage) against hepatitis B virus in patients with inflammatory bowel disease
Authors: Gisbert J. P. , Menchén L. , García‐Sánchez V. , Marín I. , Villagrasa J. R. , Chaparro M.
Published: April 2012

Background

The response rate to hepatitis B virus (HBV) vaccination in patients with inflammatory bowel disease (IBD) is low.

Aim

To compare two vaccination protocols—the standard dose and the double dose—in IBD patients.

Methods

Patients diagnosed with IBD from three tertiary hospitals were vaccinated against HBV with two different protocols: the standard protocol (Engerix‐B single dose at 0, 1 and 6 months) and the new faster protocol based on a double dose (Engerix B double dose at 0, 1 and 2 months). Anti‐HBs titres were measured 1–3 months after the last dose. A multivariate analysis was performed to identify factors that were predictive of response to the vaccine.

Results

The study sample comprised 148 patients (mean age 40 years, 69% Crohn's disease), 70% of whom were receiving immunosuppressive therapy (22% thiopurines, 23% anti‐TNF and 25% both). The standard protocol was followed in 46% of patients and the double dose protocol in 54%. Considering anti‐HBs >10 IU/L as a successful response to vaccination, the seroconversion rate was higher among patients vaccinated with the double dose than with the standard dose: 75% (95% CI, 65–85%) vs. 41% (95% CI, 29–54%) (P < 0.001). In the multivariate analysis, vaccination with the double dose was the only factor associated with a better response to the vaccine (OR, 4; 95% CI, 2–8; P < 0.001).

Conclusions

The response rate to the HBV vaccination in IBD patients is low. Administration of a double dose was associated with a higher response rate. Therefore, the double dose protocol could be a suitable option in patients with IBD.
Elevated factor VIII levels and risk of venous thrombosis
Authors: Jenkins P. Vince , Rawley Orla , Smith Owen P. , O'Donnell James S.
Published: April 2012

Modern thrombophilia testing fails to identify any underlying prothrombotic tendency in a significant number of patients presenting with objectively confirmed venous thromboemboembolism (VTE). This observation has led to a search for other novel inherited or acquired human thrombophilias. Although a number of putative mechanisms have been described, the evidence behind many of these candidates remains weak. In contrast, an increasing body of work supports the hypothesis that increased plasma factor VIII (FVIII) levels may be important in this context. An association between elevated plasma FVIII levels and VTE was first described in the Leiden Thrombophilia Study (LETS). Subsequently, these conclusions have been supported by an increasing number of independent case–control studies. Cumulatively, these studies have clearly demonstrated that high FVIII levels constitute a prevalent, dose‐dependent risk factor for VTE. Furthermore, more recent studies have shown that the risk of recurrent venous thrombosis is also significantly increased in patients with high FVIII levels. In this review, we present the evidence supporting the hypothesis that elevated FVIII levels constitute a clinically important thrombophilia. In addition, we examine the biological mechanisms that may underlie persistently elevated FVIII levels, and the pathways through which high FVIII may serve to increase thrombotic risk.
Lymph node dissection – understanding the immunological function of lymph nodes
Authors: Buettner M , Bode U
Published: April 2012

Lymph nodes (LN) are one of the important sites in the body where immune responses to pathogenic antigens are initiated. This immunological function induced by cells within the LN is an extensive area of research. To clarify the general function of LN, to identify cell populations within the lymphatic system and to describe the regeneration of the lymph vessels, the experimental surgical technique of LN dissection has been established in various animal models. In this review different research areas in which LN dissection is used as an experimental tool will be highlighted. These include regeneration studies, immunological analysis and studies with clinical questions. LN were dissected in order to analyse the different cell subsets of the incoming lymph in detail. Furthermore, LN were identified as the place where the induction of an antigen-specific response occurs and, more significantly, where this immune response is regulated. During bacterial infection LN, as a filter of the lymph system, play a life-saving role. In addition, LN are essential for the induction of tolerance against harmless antigens, because tolerance could not be induced in LN-resected animals. Thus, the technique of LN dissection is an excellent and simple method to identify the important role of LN in immune responses, tolerance and infection.
Inferring habitat suitability and spread patterns from large‐scale distributions of an exotic invasive pasture grass in north Australia
Authors: Petty Aaron M. , Setterfield Samantha A. , Ferdinands Keith B. , Barrow Piers
Published: April 2012

1. The understanding of large‐scale patterns in expanding populations of alien invasive plants can be used to infer the environmental limiting factors, habitat heterogeneity and, ultimately, the range expansion potential of invasive plants.

2. We used multivariate analysis and a novel quantile regression technique accounting for spatial autocorrelation to compare and contrast factors influencing the abundance and distribution of the African grass Andropogon gayanus (gamba grass) at two large‐scale invasion sites in the tropical savanna region of Australia. We collected data using aerial and ground surveys and tested for limiting factors using three landscape‐scale indices related to soil quality, soil moisture and invasion history.

3. In one site, gamba grass was principally colonising drainage lines and riparian areas. Occupation of these areas was limited in proportion to the distance from the original gamba grass source. In the second site, gamba grass abundance was independent of distance from the original source and was well established in all vegetation communities, although abundance was also limited in higher elevation sites away from drainage lines.

4. Comparisons between these sites with different patterns of invasion enabled the estimation of both the invasion pathways and range expansion potential of gamba grass. Our results indicated that gamba grass spreads from riparian communities to invade upland sites and has the potential to invade 70% of north Australia’s upland savanna communities.

5. Aerial surveys comprehensively assessed patterns over a larger area than ground surveys and were much more economical.

6. Synthesis and applications. Large‐scale surveys across multiple sites are critical to understanding the dynamics of recent alien species invasions where little is known about the pattern and potential range of spread. The application of quantile regression and aerial surveys shows promise as aerial surveys are efficient at capturing a large amount of data. The novel quantile regression technique we demonstrate here can account for both spatial autocorrelation and noisy ecological data from aerial surveys while returning robust results. We were thus able to demonstrate widespread colonisation of creek lines by gamba grass and recommend that management focuses on detection and eradication along drainage lines in addition to the present focus on transport corridors.
Reduced pesticide toxicity and increased woody vegetation cover account for enhanced native bird densities in organic orchards
Authors: MacLeod Catriona J. , Blackwell Grant , Benge Jayson
Published: April 2012

1. Organic farming is often promoted as a solution for counteracting the adverse impacts of agricultural intensification on biodiversity. However, it is unclear whether the biodiversity benefits derived from organic farming require an adoption of organic farming in its entirety (i.e. a systems‐level approach) or whether the benefits derived are because of just a small subset of the associated management practices.

2. Using bird survey data collected from kiwifruit orchards in New Zealand, we assessed whether orchards managed under an organic system support higher bird densities than those under integrated management systems. To determine whether biodiversity gains might also be achieved on non‐organic orchards, we tested whether variation among kiwifruit orchards in the amount of (non‐crop) woody vegetation cover, density of shelterbelts and toxicity of pesticide applications are better predictors of bird densities than management systems.

3. Composite measures of breeding season densities of all native species and the subset of native insectivores were higher on organic orchards than integrated management orchards. Densities of introduced bird species were comparable among management systems.

4. Pesticide use and habitat composition variables were better predictors of native bird densities than management system, with native bird densities negatively associated with pesticide toxicity ranking and/or positively associated with woody vegetation cover.

5. Synthesis and applications.A complete conversion to an organic system may not be required to improve biodiversity in agroecosystems. Instead, the transfer of specific land management practices known to benefit biodiversity in organic systems has the potential to enhance biodiversity in other more intensively managed systems (e.g. integrated management). This may be a path towards attaining biodiversity benefits at a larger scale, because such changes may be more straightforward than conversion to an organic system.
Embryonic Development of Kisspeptin Neurones in Rat
Authors: Desroziers E. , Droguerre M. , Bentsen A. H. , Robert V. , Mikkelsen J. D. , Caraty A. , Tillet Y. , Duittoz A. , Franceschini I.
Published: April 2012

Kisspeptins, encoded by the Kiss1 gene, play a key role in the regulation of reproductive function, although very little is known about the ontogenesis of this system. The present study aimed to determine the period of arcuate nucleus (ARC) kisspeptin cell birth and the embryonic stage and neuroanatomical sites of onset of kisspeptin immunoreactivity. Bromodeoxyuridine (BrdU) was administered to female rats at various gestational stages and double immunohistochemistry against kisspeptin and BrdU was performed on brain sections from their offspring. The period of neurogenesis of ARC kisspeptin neurones begun between embryonic day (E) 12.5 and E13.5, reached its peak at E15.5 and was not completely over at E17.5. Kiss1 mRNA was detected in mediobasal hypothalamic punches of embryos aged E14.5, E16.5, E18.5 and E22.5 by real‐time reverse transcriptase‐polymerase chain reaction. Accordingly, kisspeptin‐immunoreactive (‐IR) cells were consistently detected in the embryonic ARC from E14.5 and their number increased until E18.5 to reach approximately half the level observed in adults. Between E18.5 and E22.5, the number of kisspeptin‐IR cells and hypothalamic Kiss1 expression significantly decreased, regardless of sex, and this decrease persisted until birth. Taken together, these results demonstrate that rat ARC kisspeptin neurones are born locally during an extended embryonic period and are able to synthesise kisspeptins rapidly after their birth, consistent with the hypothesis of a role during embryonic activation of the hypothalamic‐hypophyseal‐gonadal axis. A sex‐independent decrease of kisspeptin‐IR cell numbers was observed during the perinatal period, suggestive of important regulations of kisspeptin neurones around birth.
Seasonal and age effects on energy requirements in domestic short‐hair cats (Felis catus) in a temperate environment
Authors: Bermingham E. N. , Weidgraaf K. , Hekman M. , Roy N. C. , Tavendale M. H. , Thomas D. G.
Published: April 2012

There is little information known about the energy requirements of cats in temperature climates. Energy requirement of domestic short‐haired cats was determined using three groups of mixed gender – old kept outside (approximately 9.9 years of age; 4.8 kg; n = 9), young kept outside (approximately 3.1 years of age; 3.9 kg; n = 8) or young kept inside (approximately 3.1 years of age; 3.9 kg; n = 8). Cats were housed individually for 5 weeks during summer (18.5 ± 0.5 °C) and winter (8.5 ± 0.4 °C) and were fed a commercially available maintenance diet ad libitum. In both periods, energy expenditure was determined from the rates of 2H and 18O elimination for blood H2O over a 12 day period, from a doubly labelled water bolus 2H2O (0.7 g/kg BW) and H218O (0.13 g/kg BW) administered intravenously. During the summer period, macronutrient digestibility was determined. Older cats had a reduction (p < 0.05) in apparent digestibility of dry matter (approximately 9%), energy (approximately 8%) and protein (6%). There was a significant effect of age and season on energy intake and energy expenditure. While lean mass was affected by age and season, there was no effect of age or season on energy expenditure when expressed as a proportion of lean mass. Possible seasonal differences in nutrient digestibility may explain these results.