bluuebunny/crossref_metadata_2025 huggingface dataset:
Diffusion of photoexcited carriers in graphene
Authors: Vasko F. T. , Mitin V. V.
Published: October 2012

The diffusion of electron-hole pairs, which are excited in an intrinsic graphene by the ultrashort focused laser pulse in mid-IR or visible spectral region, is described for the cases of peak-like or spread over the passive region distributions of carriers. The spatio-temporal transient optical response on a high-frequency probe beam appears to be strongly dependent on the regime of diffusion and can be used for verification of the elasic relaxation mechanism. Sign flip of the differential transmission coefficient takes place due to interplay of the carrier-induced contribution and weak dynamic conductivity of undoped graphene.
Growth and ferromagnetic resonance properties of nanometer-thick yttrium iron garnet films
Authors: Sun Yiyan , Song Young-Yeal , Chang Houchen , Kabatek Michael , Jantz Michael , Schneider William , Wu Mingzhong , Schultheiss Helmut , Hoffmann Axel
Published: October 2012

Growth of nm-thick yttrium iron garnet films and ferromagnetic resonance (FMR) linewidth properties in the films are reported. The films were grown on gadolinium gallium garnet substrates by pulsed laser deposition (PLD). Films in the 5–35 nm thickness range showed a (111) orientation and a surface roughness between 0.1 and 0.3 nm. The 10 nm films showed a 10 GHz FMR linewidth of about 6 Oe and a damping constant of 3.2 × 10−4. The FMR linewidth increases with both the surface roughness and the surface Fe deficiency. Thicker films exhibit a smaller FMR linewidth and a lower damping constant.
Complex impedance, responsivity and noise of transition-edge sensors: Analytical solutions for two- and three-block thermal models
Authors: Maasilta I. J.
Published: October 2012

The responsivity and noise of a voltage-biased superconducting transition-edge sensor depends strongly on the details of its thermal model, and the simplest theory for TES response assumes a single heat capacity connected to the heat bath. Here, analytical results are derived and discussed for the complex impedance, the responsivity and the noise of a transition-edge sensor, when the thermal model is not simple but consists of either two or three connected heat capacities. The implications of the differences of the models are discussed, as well.
Formation of jet-like spikes from the ablative Rayleigh-Taylor instability
Authors: Wang L. F. , Ye W. H. , He X. T. , Zhang W. Y. , Sheng Z. M. , Yu M. Y.
Published: October 2012

The mechanism of jet-like spike formation from the ablative Rayleigh-Taylor instability (ARTI) in the presence of preheating is reported. It is found that the preheating plays an essential role in the formation of the jet-like spikes. In the early stage, the preheating significantly increases the plasma density gradient, which can reduce the linear growth of ARTI and suppress its harmonics. In the middle stage, the preheating can markedly increase the vorticity convection and effectively reduce the vorticity intensity resulting in a broadened velocity shear layer near the spikes. Then the growth of ablative Kelvin-Helmholtz instability is dramatically suppressed and the ARTI remains dominant. In the late stage, nonlinear bubble acceleration further elongates the bubble-spike amplitude and eventually leads to the formation of jet-like spikes.
Trap-assisted tunneling resistance switching effect in CeO2/La0.7(Sr0.1Ca0.9)0.3MnO3 heterostructure
Authors: Chen X. G. , Fu J. B. , Liu S. Q. , Yang Y. B. , Wang C. S. , Du H. L. , Xiong G. C. , Lian G. J. , Yang J. B.
Published: October 2012

We reported the resistance switching (RS) behavior in the epitaxially grown CeO2/ La0.7(Sr0.1Ca0.9)0.3MnO3 (CeO2/LSCMO) heterojunctions on SrTiO3 substrate. The CeO2/LSCMO device displayed improved switching characteristics as compared to that of metal/manganite device. The switching threshold voltage showed a strong dependence on the thickness of the CeO2 layer, where a minimum/maximum thickness was required for the appearance of the resistance switching. Both set and reset threshold voltages increase with the increase of the CeO2 layer thickness due to the trap-assisted electron tunneling effect. In the meantime, the defects or vacancies in the CeO2 films, in particular, the concentration of the defects or vacancies in the interface between CeO2 and LSCMO, have a significant impact on the switching effect. These results suggest that the electron tunneling accompanied by a trapping/detrapping process at the interface is likely responsible for the RS effect in the insulator/manganite system.
Hybridized electronic states in potassium-doped picene probed by soft x-ray spectroscopies
Authors: Yamane Hiroyuki , Kosugi Nobuhiro
Published: October 2012

The electronic structure of the unoccupied and occupied states of potassium (K)-doped and undoped picene crystalline films has been investigated by using the element-selective and bulk-sensitive photon-detection methods of X-ray absorption and emission spectroscopies. We observed the formation of the doping-induced unoccupied and occupied electronic states in K-doped picene. By applying the inner-shell resonant-excitation experiments, we observed the evidence for the orbital hybridization between K and picene near the Fermi energy. Furthermore, the resonant X-ray emission experiment suggests the presence of the Raman-active vibronic interaction in K-doped picene. These experimental evidences play a crucial role in the superconductivity of K-doped picene.
Simulation of Ir(III) in Aqueous Solution: The Most Inert Ion Hydrate
Authors: Pedevilla Philipp A. , Hofer Thomas S. , Randolf Bernhard R. , Rode Bernd M.
Published: October 2012

The ab initio quantum mechanical charge field (QMCF) molecular dynamics (MD) approach at Hartree-Fock level was used to simulate the tripositive iridium ion in aqueous solution, evaluating structure and dynamics of its hydrate complex. The Ir-OH2 force constant was of particular interest because of the observed high inertness of Ir(iii) in aqueous solution. Iridium forms three hydration shells. Six water molecules coordinate the ion in the first hydration shell in a well defined octahedral geometry, and no exchanges took place during the simulation time of 15 ps. The second hydration shell is very flexible, however, with a mean residence time of a water molecule of 3.6 ps. The third shell can be identified only by a slight ordering effect. This investigation classified the Ir-OH2 force constant as the strongest ion-OH2 bond known to date.
Development of Purkinje cell degeneration in a knockin mouse model reveals lysosomal involvement in the pathogenesis of SCA6
Authors: Unno Toshinori , Wakamori Minoru , Koike Masato , Uchiyama Yasuo , Ishikawa Kinya , Kubota Hisahiko , Yoshida Takashi , Sasakawa Hiroko , Peters Christoph , Mizusawa Hidehiro , Watase Kei
Published: October 2012

Spinocerebellar ataxia type 6 (SCA6) is a neurodegenerative disease caused by the expansion of a polyglutamine tract in the Ca
v
2.1 voltage-gated calcium channel. To elucidate how the expanded polyglutamine tract in this plasma membrane protein causes the disease, we created a unique knockin mouse model that modestly overexpressed the mutant transcripts under the control of an endogenous promoter (MPI-118Q). MPI-118Q mice faithfully recapitulated many features of SCA6, including selective Purkinje cell degeneration. Surprisingly, analysis of inclusion formation in the mutant Purkinje cells indicated the lysosomal localization of accumulated mutant Ca
v
2.1 channels in the absence of autophagic response. The lack of cathepsin B, a major lysosomal cysteine proteinase, exacerbated the loss of Purkinje cells and was accompanied by an acceleration of inclusion formation in this model. Thus, the pathogenic mechanism of SCA6 involves the endolysosomal degradation pathway, and unique pathological features of this model further illustrate the pivotal role of protein context in the pathogenesis of polyglutamine diseases.
Hot-wire substoichiometric tungsten oxide films deposited in hydrogen environment with n-type conductivity
Authors: Kostis I , Michalas L , Vasilopoulou M , Konofaos N , Papaioannou G , Iliadis A A , Kennou S , Giannakopoulos K , Papadimitropoulos G , Davazoglou D
Published: October 2012

Substoichiometric tungsten oxide nanostructured films were synthesized by a hot-wire deposition technique in hydrogen-rich environment and characterized for their structural and electrical properties. A semiconducting behaviour was identified, allowing n-type conductivity even at room temperature which is an important result since it is well known that fully stoichiometric tungsten trioxide is nearly an insulator. Current–voltage characteristics for various temperatures were measured for tungsten oxide/Si heterostructures and analysed using proper modelling. As a result, the conduction mechanism inside the films was identified and found to be of a dual nature, with variable range hopping being dominant at near room temperatures. The saturation current was found to be thermally activated and the activation energy was calculated at 0.40 eV and the grain boundaries barrier at 150 meV. From Hall measurements it was also revealed that the dominant carriers are electrons and a carrier concentration of about 1014 cm−3 was estimated.
Dielectric breakdown properties of SF6–N2 mixtures in the temperature range 300–3000 K
Authors: Li Xingwen , Zhao Hu , Jia Shenli
Published: October 2012

Reduced critical electric field strength (E/N)cr is an important indicator for the evaluation of dielectric breakdown of SF6 and its mixtures. This paper aims to analytically investigate the dielectric breakdown properties of SF6–N2 mixtures. First, (α − η)/N and (E/N)cr of SF6–N2 mixtures at room temperature, and then (E/N)cr of hot SF6 at several pressures are calculated and compared with other studies. The results confirmed the validity of the present calculation method and parameters. In addition, the electron energy distribution function, reduced ionization coefficient α/N and attachment coefficient η/N of SF6–N2 mixtures are obtained at different proportions and under 1 atm in the gas temperature range 300–3000 K. Then (E/N)cr can be determined when the effective ionization coefficient (α − η)/N = 0. The results show that in a certain temperature range, due to the effect of N2 on reduction in the proportion of high-energy electrons, (E/N)cr of SF6–N2 mixtures will be enhanced by increasing N2.
Controlling surface hydroxylation of nanoporous silica by ion bombardment
Authors: Van Cleve E , Charnvanichborikarn S , Kucheyev S O
Published: October 2012

Due to a large fraction of undercoordinated surface atoms in nanoporous solids, the surface composition could have a profound effect on their properties. Here, we use mass spectrometry to study ion-beam-induced desorption from silica aerogels. Results show that the dominant ion-beam-induced desorption species is the hydrogen molecule. Bombardment with ions of different masses causes dehydroxylation of silica nanoligaments, with the desorption efficiency scaling linearly with the electronic stopping power of ions. These results demonstrate that ion bombardment can be used for controlling surface hydroxylation of nanoporous silica.
Evolution at Two Levels in Fire Ants: The Relationship between Patterns of Gene Expression and Protein Sequence Evolution
Authors: Hunt Brendan G. , Ometto Lino , Keller Laurent , Goodisman Michael A.D.
Published: October 2012

Variation in protein sequence and gene expression each contribute to phenotypic diversity, and may be subject to similar selective pressures. Eusocial insects are particularly useful for investigating the evolutionary link between protein sequence and condition-dependent patterns of gene expression because gene expression plays a central role in determining differences between eusocial insect sexes and castes. We investigated the relationship between protein coding sequence evolution and gene expression patterns in the fire ants Solenopsis invicta, S. richteri, and their hybrids to gain greater insight into how selection jointly operates on gene expression and coding sequence. We found that genes with high expression variability within castes and sexes were frequently differentially expressed between castes and sexes, as well as between species and hybrids. These results indicate that genes showing high variation in expression in one context also tend to show high variation in expression in other contexts. Our analyses further revealed that variation in both intra- and interspecific gene expression was positively associated with rate of protein sequence evolution in Solenopsis. This suggests that selective constraints on a gene operate both at the level of protein sequence and at the level of gene expression regulation. Overall, our study provides one of the strongest demonstrations that selective constraints mediate both protein sequence evolution and gene expression variability across different biological contexts and timescales.
Testing Theories of Congressional—Presidential Interaction with Veto Override Rates
Authors: Martin Gregory J.
Published: October 2012

The ability to veto legislation is the most important formal power of the presidency in the legislative process, and presidents' veto behavior has thus attracted a great deal of theoretical interest. Game-theoretic models of congressional—presidential interactions explain vetoes by incorporating incomplete information over the distribution of presidential or congressional types. In this article, I examine two prominent such theories, as well as a simple “noisy” extension of a complete information theory. I show that each makes strong predictions not only about vetoes themselves but also about the resulting override votes; given that overrides are so closely connected with vetoes, any valid theory of the latter must be able to successfully explain the former. I test these predictions empirically and show that support for each of these theories in presidential veto and override data from 1973 to 2008 is quite weak. This negative result suggests that current models of the veto are incomplete; I sketch some possibilities for extension in the conclusion.
Molecular mechanisms of LKB1 induced cell cycle arrest
Authors: Zhong Dian‐sheng , Sun Lin‐lin , Dong Li‐xia
Published: October 2012

LKB1 is a serine/threonine protein kinase mutated in patients with Peutz‐Jeghers syndrome. Biallelic inactivation of LKB1 is present in up to 30% of cases of non‐small cell lung cancer (NSCLC). As a tumor suppressor, LKB1 functions in arresting the cell cycle and inhibiting cell growth. LKB1 leads to induction of p21/WAF1 expression in a p53‐dependent mechanism, which is mediated by cytoplasmic LKB1 initiating negative regulation of cell growth or nuclear LKB1 directly involved in transcriptional regulation of p21/WAF1. Alternatively, p53 and p21/WAF1‐independent mechanism of regulating cell cycle by LKB1 is also reported.
Aquaporin‐4 Deficiency Attenuates Opioid Dependence through Suppressing Glutamate Transporter‐1 Down‐regulation and Maintaining Glutamate Homeostasis
Authors: Yan Hai‐Tao , Wu Ning , Lu Xin‐Qiang , Su Rui‐Bin , Zheng Jian‐Quan , Li Jin
Published: October 2012

Background

Glutamate homeostasis plays a critical role in mediating the addiction‐related behaviors. Therefore, preventing the disruption or reestablishing of it is a novel strategy for the treatment of addiction. Glutamate transporters are responsible for clearing extracellular glutamate and maintaining glutamate homeostasis. Our previous work demonstrated that aquaporin‐4 (AQP4) deficiency attenuated morphine dependence, but the mechanisms are unclear. According to the recent evidence that AQP4 might form a functional complex with glutamate transporter‐1 (GLT‐1), this study focused on whether AQP4 participates in the modulation of GLT‐1 and glutamate homeostasis in morphine‐dependent mice.

Results

We found that AQP4 knockout prevented the down‐regulations of GLT‐1 expression and glutamate clearance when mice were repeatedly treated with morphine. Further study revealed that inhibition of GLT‐1 by dihydrokainic acid (DHK) initiated morphine dependence in AQP4 knockout mice. In addition, AQP4 knockout abolished both decreases and increases in the extracellular glutamate levels in the prefrontal cortex during repeated morphine treatment and naloxone‐precipitated withdrawal.

Conclusion

AQP4 deficiency suppresses the down‐regulation of GLT‐1, and the disruption of glutamate homeostasis caused by repeated exposure to morphine, pointing to a strategy for maintaining glutamate homeostasis and thereby treating addiction through the modulation of AQP4 function and expression.
Plant defense against fall armyworm in micro‐sympatric maize (Zea mays ssp. mays) and Balsas teosinte (Zea mays ssp. parviglumis)
Authors: Takahashi Chelsea G. , Kalns Lauren L. , Bernal Julio S.
Published: October 2012

Maize [Zea mays L. ssp. mays (Poaceae)] was domesticated from Balsas teosinte (Zea mays ssp. parviglumis Iltis & Doebley) in present‐day Mexico. Fall armyworm, Spodoptera frugiperda JE Smith (Lepidoptera: Noctuidae), is among the most important pests of maize in Mexico and Central America. We compared the strength of plant defenses against fall armyworm between micro‐sympatric landrace maize and Balsas teosinte in the field and laboratory. The field comparison, conducted in Mexico, consisted of comparing the frequency of fall armyworm infestation between young maize and Balsas teosinte plants in dryland agricultural fields in which Balsas teosinte grew as a weed. The laboratory comparison contrasted the performance of fall armyworm larvae provided a diet of leaf tissue excised from maize or Balsas teosinte plants that were intact or had been primed by larval feeding. In the field, maize plants were more frequently infested with fall armyworm than Balsas teosinte plants: over 3 years and three fields, maize was infested at a ca. 1.8‐fold greater rate than Balsas teosinte. In the laboratory, larval growth, but not survivorship, was differently affected by feeding on maize vs. Balsas teosinte, and on primed vs. intact plants. Specifically, survivorship was ca. 98%, and did not differ between maize and Balsas teosinte, nor between primed and intact plants. Larvae grew less on intact vs. primed maize, and similarly on intact vs. primed Balsas teosinte; overall, growth was 1.2‐fold greater on maize compared to Balsas teosinte, and on primed compared to intact plants. Parallel observations showed that the differences in growth could not be attributed to the amount of leaf tissue consumed by larvae. We discuss our results in relation to differences in the strength of plant defenses between crops and their ancestors, the relevance of unmanaged Balsas teosinte introgression in the context of fall armyworm defenses in maize, and whether greater growth of larvae on primed vs. intact plants signifies herbivore offense.
Differential effects of blockade of ERG channels on gamma oscillations and excitability in rat hippocampal slices
Authors: Fano Silvia , Çalışkan Gürsel , Heinemann Uwe
Published: October 2012

Agents such as sertindole and astemizole affect heart action by inducing long‐QT syndrome, suggesting that apart from their neuronal actions through histamine receptors, 5‐HT2 serotonin receptors and D2 dopamine receptors they also affect ether‐a‐go‐go channels and particularly ether‐a‐go‐go‐related (ERG) potassium (K+) channels, comprising the Kv11.1, Kv11.2 and Kv11.3 voltage‐gated potassium currents. Changes in ERG K+ channel expression and activity have been reported and may be linked to schizophrenia [Huffaker, S.J., Chen, J., Nicodemus, K.K., Sambataro, F., Yang, F., Mattay, V., Lipska, B.K., Hyde, T.M., Song, J., Rujescu, D., Giegling, I., Mayilyan, K., Proust, M.J., Soghoyan, A., Caforio, G., Callicott, J.H., Bertolino, A., Meyer‐Lindenberg, A., Chang, J., Ji, Y., Egan, M.F., Goldberg, T.E., Kleinman, J.E., Lu, B. & Weinberger DR. (2009). Nat. Med., 15, 509–518; Shepard, P.D., Canavier, C.C. & Levitan, E.S. (2007). Schizophr Bull., 33, 1263–1269]. We have previously shown that histamine H1 blockers augment gamma oscillations (γ) which are thought to be involved in cognition and storage of information. These effects were particularly pronounced for γ induced by acetylcholine. Here we have compared neuronal effects of three agents which interfere with ERG K+ channels. We found that astemizole and sertindole, but not the Kv11 channel blocker E4031, augmented γ induced by acetylcholine in hippocampal slices. Kainate‐induced γ were only affected by astemizole. Evoked responses induced by stratum radiatum stimulation in area CA1 revealed that only E4031 augmented stimulus‐induced synaptic potentials and neuronal excitability. Our findings suggest that Kv11 channels are involved in neuronal excitability without clear effects on γ and that the effect of astemizole is related to actions on H1 receptors.
Compensatory dynamics and the stability of phytoplankton biomass during four decades of eutrophication and oligotrophication
Authors: Jochimsen Marc C. , Kümmerlin Reiner , Straile Dietmar
Published: October 2012

The link between compensatory dynamics and regime shifts is not well understood. We analyse a regime shift in phytoplankton in a large lake with respect to: (1) environmental forcing and (2) the type of dynamics (compensatory or synchronous) between phytoplankton groups. The regime shift in phytoplankton was related to gradual changes in nutrient levels, but unrelated to an almost concurrent shift in climatic conditions. The relationship between total phytoplankton biomass and phosphorus concentrations was sigmoid. Trajectories of phytoplankton biomass and community dynamics suggest that eutrophication effects can successfully be reversed when management efforts decrease nutrient loading to a level sufficiently low to overcome community resilience. The regime shift was associated with a loss of biomass compensation and compensatory dynamics among the phytoplankton groups. This suggests that the type of interactions is important for a better understanding of the existence and shape of nonlinear responses of phytoplankton biomass to environmental change.
Effects of disturbance on an urban river food web
Authors: CALIZZA EDOARDO , COSTANTINI MARIA LETIZIA , ROSSI DAVID , CARLINO PASQUALE , ROSSI LORETO
Published: October 2012

1. Natural and anthropogenic disturbances are influential factors in river ecosystems. Lowland rivers that cross urbanised areas experience direct disturbance due to urbanisation, affecting suitability for many vertebrate and invertebrate species and with important implications for ecosystem functioning and stability. In addition, lowland rivers are potentially subjected to major flood events, whose effects may be exacerbated by urbanisation in the river basin. A greater understanding of the combined effects of flood disturbance and urbanisation is needed if we are to preserve riverine ecosystems and improve management strategies.

2. We characterised macroinvertebrate, detritus‐based food webs upstream and downstream of Rome (Italy) before a period of exceptional flooding and at intervals until 71 days following the final flood event. We studied community and food‐web characteristics, combining carbon and nitrogen stable isotope analysis with macroinvertebrate population census data.

3. The flood altered the species assemblage at both upstream and downstream locations. The food webs shifted towards a more complex configuration, with increased trophic generalism, linkage density and mean chain length. However, the food web at the upstream location gradually recovered its pre‐flood configuration, whereas at the downstream location, where flood effects were stronger, the food web showed little capacity for recovery within the time span of the study. The contrasting food‐web responses can be explained with reference to differences in resource availability for detritivores and predators and in water turbidity, which in turn reflect an interaction between flood disturbance and river basin urbanisation.

4. The description of short‐term variations in food‐web properties may help to improve ecosystem monitoring and the management of freshwater bodies and can be used to assess short‐term and long‐term effects of disturbance. A better understanding of the negative effects of urban pressure on macroinvertebrate community stability should help to define appropriate measures for the conservation and restoration of urbanised river areas, especially given that extreme flood events are expected to increase due to climatic change.
Dataset for reporting of prostate carcinoma in radical prostatectomy specimens: recommendations from the International Collaboration on Cancer Reporting
Authors: Kench James G , Delahunt Brett , Griffiths David F , Humphrey Peter A , McGowan Thomas , Trpkov Kiril , Varma Murali , Wheeler Thomas M , Srigley John R
Published: October 2012

This project was designed to harmonise the Royal College of Pathologists, College of American Pathologists and Royal College of Pathologists of Australasia datasets, checklists and structured reporting protocols for examination of radical prostatectomy specimens, with the aim of producing a common, internationally agreed, evidence‐based dataset for prostate cancer reporting. The International Collaboration on Cancer Reporting prostate cancer expert review panel analysed the three existing datasets, identifying concordant items and classified these data elements as ‘required’ (mandatory) or ‘recommended’ (non‐mandatory), on the basis of the published literature up to August 2011. Required elements were defined as those that have agreed evidentiary support at NHMRC level III‐2 or above. Consensus response values were formulated for each item. Twelve concordant pathology data elements were identified, and, on review, all but one were included as required elements for tumour staging, grading, or prediction of prognosis. There was minor discordance between the three existing datasets for another eight items, with two of these being added to the required data set. Another 11 elements with a lesser level of evidentiary support were included in the recommended dataset. This process was found to be an efficient method for producing an evidence‐based dataset for prostate cancer. Such internationally agreed datasets should facilitate meaningful comparison of benchmarking data, epidemiological studies, and clinical trials.
The implementation of a tobacco dependence education curriculum in a Swiss Dental Hygiene School – an 8‐year review
Authors: Ramseier CA , Burri M , Berres F , Davis JM
Published: October 2012

Objective

The aim of our investigation was to review the implementation of a comprehensive tobacco dependence education (TDE) curriculum at the Medi School of Dental Hygiene (MSDH), Bern, Switzerland, 2001–2008.

Methods

In 2001, new forms to record patients' tobacco use history and willingness to quit were created for all the MSDH patients. In 2002, a new theoretically based tobacco dependence treatment protocol was implemented into the MSDH curriculum. Students received instruction on how to provide brief tobacco use dependence interventions as well as maintain detailed records of patient tobacco use and cessation interventions for every smoker at all dental hygiene visits.

Results

In 2002, 17 lecture hours were added to the following subjects: pathology, periodontology, preventive dentistry, pharmacology and psychology. During the same time period, 2213 patients (56.9% women) have visited the MSDH. Smoking status was recorded in 85.7% of all the patients (30.2% smokers). Brief tobacco use interventions were recorded in 36.8% of all smokers while 7.6% of these have reported to quit smoking.

Conclusions

Overall, the new TDE curriculum was successfully implemented and accepted by the MSDH faculty. Applications in the clinical practice, however, may still be improved to better identify smokers and increase initial and follow‐up interventions potentially leading to higher quit rates.
The evolution of floral mimicry: identifying traits that visually attract pollinators
Authors: Jersáková Jana , Jürgens Andreas , Šmilauer Petr , Johnson Steven D.
Published: October 2012

Some orchids have been proposed to be Batesian floral mimics imitating flowers of sympatric rewarding species to attract pollinators. It is not yet well understood which traits are critical for pollinator attraction, although colour, shape and scent have all been implicated.

We conducted field‐based behavioural experiments using pairwise combinations of plastic flowers differing in spectral and shape properties offered to long‐proboscid tabanid flies (Philoliche aethiopica) at two sites – one where the fly‐pollinated orchid mimic Disa pulchra occurs with its pink‐flowered model, the iris Watsonia lepida and another where the flies forage on a blue‐flowered rewarding plant Agapanthus campanulatus.

Flies intensively visited and probed plastic flowers of colours indistinguishable in a fly vision model from those of the rewarding plants. Inflorescence architecture and brightness of plastic flowers made little difference to fly attraction, but those that matched the shape and nectar guides of Watsonia flowers were significantly more attractive.

Flowers of the three focal plant species are weakly scented and divergent in scent chemistry.

This study shows that traits that mimic, in order of importance, the spectra, shape and nectar guide patterns of flowers of rewarding plants would be under strong selection in food‐deceptive orchids as they maximize attractiveness to their pollinators. Our experiments also help to explain why deceptive orchids in general often seem to match the flowers of sympatric rewarding plants more in visual attributes than in scent chemistry.
Increased resolution in neutral atom microscopy
Authors: WITHAM P. J. , SÁNCHEZ E. J.
Published: October 2012

The neutral atom microscope uses a beam of thermal noncharged atoms or molecules to probe an atomic surface with very low interaction energies (<70 meV). Continued optimization of the ‘pinhole’ neutral atom microscope has improved resolution to 0.35 μm. Recent images are presented demonstrating resolution and the contrast mechanisms identified so far. The future potential for sub‐100 nm resolution is discussed.
Migration and dispersal patterns of bats and their influence on genetic structure
Authors: Moussy Caroline , Hosken D.J. , Mathews F. , Smith G.C. , Aegerter J.N. , Bearhop S.
Published: October 2012

Bats are important ecosystems service providers, make a significant contribution to biodiversity and can be important pests and disease vectors. In spite of this, information on their migration and dispersal patterns is limited.

In temperate bats, migration is most evident in females. This reflects seasonal differences in their habitat requirements, and the fact that seasonally suitable sites can be geographically distant. Tropical bats mainly migrate to track variation in food availability.

Little direct information is available on the patterns and drivers of bat dispersal, although drivers may include mate competition and inbreeding avoidance. In many temperate species, differential energy requirements and local resource competition among the sexes drive sexual segregation in the summer: females remain philopatric to their natal region, and frequently to their natal colony, while males disperse. In contrast, many tropical Pteropodidae form single‐male/multi‐female groups in which local resource defence contributes to female‐biased or all‐offspring dispersal from the natal site.

Population genetic studies are the most common source of evidence used to infer the spatial dynamics of bats. As expected, migratory species tend to have less genetically structured populations over large geographical scales due to mating outside of breeding areas, weak migratory connectivity and long‐distance movements. In contrast and as expected, populations of sedentary species tend to be more differentiated at smaller geographical scales.

Despite this general pattern, a range of factors, including historical events, dispersal capabilities, and behavioural, ecological and geographical barriers, are implicated in the genetic partitioning of bat populations, irrespective of movement patterns. These factors limit the study of bat movements using only genetic methods.

Combining population genetics with other methods, such as mark–recapture, tracking or stable isotope analysis, should provide more insight into the movements of these ecologically and economically important species.
Reproductive success of female leopards Panthera pardus: the importance of top‐down processes
Authors: Balme Guy A. , Batchelor Andrew , de Woronin Britz Natasha , Seymour Greg , Grover Michael , Hes Lex , Macdonald David W. , Hunter Luke T.B.
Published: October 2012

Long‐term studies on large felids are rare and yet they yield data essential to understanding the behaviour of species and the factors that facilitate their conservation.

We used the most extensive data set so far compiled on leopards Panthera pardus to establish baseline reproductive parameters for females and to determine the demographic and environmental factors that affect their lifetime reproductive success.

We used comprehensive sightings reports and photographs from ecotourism lodges in the Sabi Sand Game Reserve, South Africa, to reconstruct life histories for 44 female leopards that gave birth to 172 litters over a 32‐year period.

Leopards appeared to exhibit a birth pulse; most litters were born in the wet season, particularly in December. Mean age at first parturition (n = 26, mean ± standard error = 46 ± 2 months, range = 33–62) was older than previously recorded, possibly due to elevated intraspecific competition. Average litter size was 1.9 ± 0.1 (n = 140, range = 1–3) and declined with maternal age. Age of litters at independence (n = 52, 19 ± 1 months, range = 9–31) was inversely related to prey abundance but did not affect the likelihood of recruitment of offspring. Interbirth intervals differed following successful litters (in which at least one cub survived to independence; n = 55, 25 ± 1 months, range = 14–39) and unsuccessful litters (n = 46, 11 ± 1 months, range = 4–36), as did the time taken to replace litters.

Variation in lifetime reproductive success was influenced mainly by differences in cub survival, which was related to maternal age and vulnerability to infanticide. Cub survival (37%) declined as females got older, perhaps because mothers relinquished portions of their home ranges to philopatric daughters. Male leopards were responsible for many (40%) cub deaths and females appeared to adopt severalstrategies to counter the risk of infanticide, including paternity confusion and displaying a period of reduced fertility immediately after a resident male was replaced.

Our results suggest that the reproductive success of female leopards is regulated primarily by top‐down processes. This should be taken into account in management decisions, particularly when managers are considering the implementation of invasive activities such as legal trophy hunting.
Effectiveness of blood transfusions and risk factors for mortality in children aged from 1 month to 4 years at the Bon Marché Hospital, Bunia, Democratic Republic of the Congo
Authors: Mueller Yolanda , Bastard Mathieu , Ehounou Geneviève , Itama Jeff , Quéré Michel , de la Tour Roberto , Vala Louis , Etard Jean‐François , Bottineau Marie‐Claude
Published: October 2012

Objective  To assess the effectiveness of blood transfusions in a hospital of north‐eastern Democratic Republic of the Congo.

Methods  Prospective study of children admitted for severe anaemia. During admission, data were collected on clinical condition and haemoglobin levels, before and after blood transfusion. A linear regression model was built to explore factors associated with haemoglobin level after transfusion. Risk factors for mortality were explored through multivariate logistic regression.

Results  Haemoglobin level (Hb) was below 4 g/dl in 35% (230/657), between 4 and 6 g/dl in 58% (348/657) and at least 6 g/dl in another 6% (43/657) of the transfused children. A transfusion of 15 ml/kg of whole blood increased the Hb from 4.4 to 7.8 g/dl. Haemoglobin level after transfusion was associated with baseline Hb, quantity of delivered blood and history of previous transfusions. Overall case‐fatality rate was 5.6% (37/657). Risk factors for deaths were co‐morbidities such as chest infection, meningitis or malnutrition, Hb ≥ 6 g/dl, impaired consciousness or jugular venous distention on admission, and provenance.

Conclusion  Transfusion was a frequent practice, the use of which could clearly have been rationalised. While indications should be restricted, quantities of transfused blood should be adapted to needs.
Improved but unsustainable: accounting for sachet water in post‐2015 goals for global safe water
Authors: Stoler Justin
Published: October 2012

The advent and rapid spread of sachet drinking water in West Africa presents a new challenge for providing sustainable access to global safe water. Sachet water has expanded drinking water access and is often of sufficient quality to serve as an improved water source for Millennium Development Goals (MDG) monitoring purposes, yet sachets are an unsustainable water delivery vehicle due to their overwhelming plastic waste burden. Monitoring of primary drinking water sources in West Africa generally ignores sachet water, despite its growing ubiquity. Sub‐Saharan Africa as a region is unlikely to meet the MDG Target for drinking water provision, and post‐2015 monitoring activities may depend upon rapid adaptability to local drinking water trends.
Invasive pulmonary aspergillosis in non‐neutropenic patients with and without underlying disease: A single‐centre retrospective analysis of 52 subjects
Authors: DAI ZHICHU , ZHAO HAIJIN , CAI SHAOXI , LV YANHUA , TONG WANCHENG
Published: October 2012

Background and objective:  Invasive pulmonary aspergillosis (IPA) remains a life‐threatening infection in patients with prolonged neutropenia. Few data are available on IPA in non‐neutropenic patients without underlying immunocompromising conditions.

Methods:  All non‐neutropenic patients managed at the institution for a proven and probable IPA over the last 10 years were reviewed retrospectively, and the difference between non‐neutropenic patients with and without underlying disease was investigated.

Results:  Among 52 cases of IPA analysed here, 33 were histologically proven; 19 were probable. Forty‐two (80.8%) patients had underlying diseases; 10 (19.2%) patients had no any underlying diseases. There is a significant difference in seasonal distribution among patients with underlying conditions (P = 0.026), but no seasonal difference was found in the other group (P = 0.622). The only significant difference in symptoms between the two groups was fever (P = 0.015). Radiological findings were non‐specific in the two groups. Despite treatment, the overall crude mortality rate among 52 patients was 39%. The overall mortality rate in patients with underlying disease was 45%, while that in patients without underlying conditions was 11%. A Cox multivariate analysis showed that organ failure (hazard ratios: 8.739, 95% CI: 3.770–20.255; P = 0.000) was independently associated with overall mortality.

Conclusions:  Clinical features of IPA are not well known in non‐neutropenic patients, especially in those without underlying conditions. In this study, organ failure was associated with a lower rate of survival of non‐neutropenic patients with IPA.
Partial outlet obstruction in rabbits: Duration versus severity
Authors: Levin Robert M , Schuler Catherine , Leggett Robert E , Callaghan Connor , Maknuru Shilpika
Published: October 2012

Objectives

Oxidative stress is a major etiology of obstructed bladder dysfunction. The major goal of the current study was to correlate the level of oxidative stress with both the severity and duration of obstruction.

Methods

A total of 32 New Zealand White rabbits were divided into four equal groups. Groups 1–3 received partial bladder outlet obstructions by standard methods and survived for 4, 8 or 12 weeks. Group 4 received sham surgery at the end of each time period, isolated strips were taken for contractility studies and the balance of the bladder was frozen as muscle and mucosa for quantification of nitrotyrosine and carbonyl‐oxidized proteins derivatized into dinitrophenyl. For each duration, the eight rabbits were divided into three severity groups: mild, intermediate or severe decompensation.

Results

Contractile responses decreased in proportion to both severity and duration. The level of both oxidative products correlated to a much higher degree with the level of severity than the duration. There were significant decreases in the contractile responses in the mild decompensation group, whereas the level of derivatized into dinitrophenyl and nitrotyrosine of the muscle remained at control levels. This was not the case for the 4 weeks obstructed group.

Conclusions

These findings suggest that the etiology for the mechanism of contractile dysfunction is not an oxidative stress.
Myostatin inhibits proliferation of human urethral rhabdosphincter satellite cells
Authors: Akita Yasuyuki , Sumino Yasuhiro , Mori Ken‐ichi , Nomura Takeo , Sato Fuminori , Mimata Hiromitsu
Published: October 2012

Objectives

Myostatin, a member of the transforming growth factor‐β superfamily, is a negative regulator of myogenesis in skeletal muscle. We examined the effect of myostatin and myostatin inhibition by an antagonistic agent, follistatin, on growth of human urethral rhabdosphincter satellite cells (muscle stem cells) to develop a new strategy for treatment of stress urinary incontinence.

Methods

Rhabdosphincter satellite cells were cultured and selected by magnetic affinity cell sorting using an anti‐neural cell adhesion molecule antibody. The cells were transfected with simian virus‐40 antigen to extend their lifespan. A cell proliferation assay, a cell cycle analysis and an investigation of signal transduction were carried out. The autocrine action of endogenous myostatin by western blotting, real‐time reverse transcription polymerase chain reaction and immunoneutralization using an anti‐myostatin antibody was also evaluated.

Results

Selectively cultured cells expressed markers of striated muscles and successfully differentiated into myotubes. Myostatin inhibited proliferation of these cells through Smad2 phosphorylation and cell cycle arrest. Inhibitory effects of myostatin were reversed by addition of follistatin. However, rhabdosphincter satellite cells did not appear to use autocrine secretion of myostatin to regulate their proliferation.

Conclusions

Inhibition of myostatin function might be a useful pathway in the development of novel strategies for stimulating rhabdosphincter cells regeneration to treat stress urinary incontinence.
Spatial regression methods capture prediction uncertainty in species distribution model projections through time
Authors: Swanson Alan K. , Dobrowski Solomon Z. , Finley Andrew O. , Thorne James H. , Schwartz Michael K.
Published: October 2012

Aim

The uncertainty associated with species distribution model (SDM) projections is poorly characterized, despite its potential value to decision makers. Error estimates from most modelling techniques have been shown to be biased due to their failure to account for spatial autocorrelation (SAC) of residual error. Generalized linear mixed models (GLMM) have the ability to account for SAC through the inclusion of a spatially structured random intercept, interpreted to account for the effect of missing predictors. This framework promises a more realistic characterization of parameter and prediction uncertainty. Our aim is to assess the ability of GLMMs and a conventional SDM approach, generalized linear models (GLM), to produce accurate projections and estimates of prediction uncertainty.

Innovation

We employ a unique historical dataset to assess the accuracy of projections and uncertainty estimates from GLMMs and GLMs. Models were trained using historical (1928–1940) observations for 99 woody plant species in California, USA, and assessed using temporally independent validation data (2000–2005).

Main conclusions

GLMMs provided a closer fit to historic data, had fewer significant covariates, were better able to eliminate spatial autocorrelation of residual error, and had larger credible intervals for projections than GLMs. The accuracy of projections was similar between methods but GLMMs better quantified projection uncertainty. Additionally, GLMMs produced more conservative estimates of species range size and range size change than GLMs. We conclude that the GLMM error structure allows for a more realistic characterization of SDM uncertainty. This is critical for conservation applications that rely on honest assessments of projection uncertainty.
Making sense of immigration policy:Argentina, 1870–1930
Authors: Sánchez‐Alonso Blanca
Published: October 2012

The aim of this article is to disentangle the different forces that shapedArgentinian immigration policy from 1870 to 1930. A new index of immigration policy is presented, showing how immigration restrictions increased over time but, in contrast with theUS,Argentina remained open to mass migration until the 1930s. The quantitative evidence presented here suggests that there were economic reasons to restrict immigration prior to the 1930s, namely rising inequality, the closing of the frontier, and the declining relative quality of immigrants. A political economy interpretation helps to understand the long‐run evolution of immigration policy. Labour interests could not be translated intoParliament in a direct way. A large share of workers did not have the right to vote simply because they were foreigners. Inequality influenced immigration policy through social unrest since those negatively affected by massive immigration developed alternative actions: general strikes, labour unrest, and violence. Contrary to what economic theory would have predicted, anti‐immigration legislation came fromArgentinian capital and landowners who feared political and social unrest.
Pannonia Imperilled: Why Danilo Kiš Still Matters
Authors: COX JOHN K.
Published: October 2012

This essay explores the significance of the works of the Serbian–Jewish–Yugoslav writer Danilo Kiš (1935–89) more than twenty years after his untimely passing. To understand Kiš's place in Serbian culture today, it is necessary to revisit the controversies that bedevilled his public reception in Yugoslavia in the 1970s and 1980s; to understand Kiš's place in Central European history today, though, it is necessary to broaden our familiarity with his increasingly accessible corpus of writing and recontextualize his proverbially anti‐nationalistic and apolitical positions. With an expanded reading of Kiš, he emerges as a useful source of information and critique on Yugoslavia's ‘self‐managing’ socialist system itself as well as a proponent of expanded notions of both East European and Central European identity and of an emotionally authentic if controversial thesis of totalitarian equivalence between fascism and communism.