bluuebunny/crossref_metadata_2025 huggingface dataset:
Electron-phonon interactions in MoS2 probed with ultrafast two-dimensional visible/far-infrared spectroscopy
Authors: Guo Xunmin , Chen Hailong , Wen Xiewen , Zheng Junrong
Published: May 2015

An ultrafast two-dimensional visible/far-IR spectroscopy based on the IR/THz air biased coherent detection method and scanning the excitation frequencies is developed. The method allows the responses in the far-IR region caused by various electronic excitations in molecular or material systems to be observed in real time. Using the technique, the relaxation dynamics of the photo-excited carriers and electron/phonon coupling in bulk MoS2 are investigated. It is found that the photo-generation of excited carriers occurs within two hundred fs and the relaxation of the carriers is tens of ps. The electron-phonon coupling between the excitations of electrons and the phonon mode E1u of MoS2 is also directly observed. The electron excitation shifts the frequency of the phonon mode 9 cm−1 higher, resulting in an absorption peak at 391 cm−1 and a bleaching peak at 382 cm−1. The frequency shift diminishes with the relaxation of the carriers.
Exploring the effective photon management by InP nanoparticles: Broadband light absorption enhancement of InP/In0.53Ga0.47As/InP thin-film photodetectors
Authors: Fu Dong , Liu Jietao , Zhu Xi , Li Jian , Xu Yun , Song Guofeng , Wei Xin
Published: May 2015

High-index dielectric and semiconductor nanoparticles with the characteristics of low absorption loss and strong scattering have attracted more and more attention for improving performance of thin-film photovoltaic devices. In this paper, we focus our attention on InP nanoparticles and study the influence of the substrate and the geometrical configurations on their scattering properties. We demonstrate that, compared with the InP sphere, the InP cylinder has higher coupling efficiency due to the stronger interactions between the optical mode in the nanoparticle and its induced mirror image in the substrate. Moreover, we propose novel thin-film InGaAs photodetectors integrated with the periodically arranged InP nanoparticles on the substrate. Broadband light absorption enhancement is achieved over the wavelength range between 1.0 μm and 1.7 μm. The highest average absorption enhancement of 59.7% is realized for the photodetector with the optimized cylinder InP nanoparticles. These outstanding characteristics attribute to the preferentially forward scattering of single InP nanoparticle along with the effective coupling of incident light into the guided modes through the collective diffraction effect of InP nanoparticles array.
Real-time investigation of dynamic protein crystallization in living cells
Authors: Schönherr R. , Klinge M. , Rudolph J. M. , Fita K. , Rehders D. , Lübber F. , Schneegans S. , Majoul I. V. , Duszenko M. , Betzel C. , Brandariz-Nuñez A. , Martinez-Costas J. , Duden R. , Redecke L.
Published: May 2015

X-ray crystallography requires sufficiently large crystals to obtain structural insights at atomic resolution, routinely obtained in vitro by time-consuming screening. Recently, successful data collection was reported from protein microcrystals grown within living cells using highly brilliant free-electron laser and third-generation synchrotron radiation. Here, we analyzed in vivo crystal growth of firefly luciferase and Green Fluorescent Protein-tagged reovirus μNS by live-cell imaging, showing that dimensions of living cells did not limit crystal size. The crystallization process is highly dynamic and occurs in different cellular compartments. In vivo protein crystallization offers exciting new possibilities for proteins that do not form crystals in vitro.
Pt silicide/poly-Si Schottky diodes as temperature sensors for bolometers
Authors: Yuryev V. A. , Chizh K. V. , Chapnin V. A. , Mironov S. A. , Dubkov V. P. , Uvarov O. V. , Kalinushkin V. P. , Senkov V. M. , Nalivaiko O. Y. , Novikau A. G. , Gaiduk P. I.
Published: May 2015

Platinum silicide Schottky diodes formed on films of polycrystalline Si doped by phosphorus are demonstrated to be efficient and manufacturable CMOS-compatible temperature sensors for microbolometer detectors of radiation. Thin-film platinum silicide/poly-Si diodes have been produced by a CMOS-compatible process on artificial Si3N4/SiO2/Si(001) substrates simulating the bolometer cells. Layer structure and phase composition of the original Pt/poly-Si films and the Pt silicide/poly-Si films synthesized by a low-temperature process have been studied by means of the scanning transmission electron microscopy; they have also been explored by means of the two-wavelength X-ray structural phase analysis and the X-ray photoelectron spectroscopy. Temperature coefficient of voltage for the forward current of a single diode is shown to reach the value of about −2%/ °C in the temperature interval from 25 to 50 °C.
Effects of large laser bandwidth on stimulated Raman scattering instability in underdense plasma
Authors: Zhao Yao , Yu Lu-Le , Zheng Jun , Weng Su-Ming , Ren Chuang , Liu Chuan-Sheng , Sheng Zheng-Ming
Published: May 2015

The effects of laser bandwidth on stimulated Raman scattering (SRS) instability in underdense plasma are studied by particle-in-cell simulations. In the simulations, sinusoidal frequency modulation of the incident laser pulse is used. By changing the size of bandwidth, it is shown that the linear growth of SRS can be suppressed considerably, provided the laser bandwidth is much larger than the SRS linear growth rate. Simulations also show that by choosing the proper frequency modulation parameters or decreasing the linear growth rate of SRS, the inhibitory effects become more obvious. The plasma electron temperature tends to weaken the bandwidth effects especially when it is over a keV level. The laser bandwidth can only increase the time duration for linear growth but cannot diminish the instability completely.
Angular dependence of the spin textures in two-dimensional chiral magnets
Authors: Tang Dan , Qi Yang
Published: May 2015

The angular dependence of spin textures in thin helimagnetic films is investigated by a Monte Carlo simulation. When an external field is applied at an angle relative to the film normal, we find that the skyrmion states with broken axis-symmetric structure are able to persist over a wide range of angles by changing the spin orientation. In addition, the uniaxial anisotropy is able to stabilize the distorted skyrmions. This behavior reflects the robust topological stability of skyrmion states in helimagnets and favors their application in spintronic devices.
Nano-electromechanical rotation of graphene and giant enhancement in dielectric anisotropy in a liquid crystal
Authors: Basu Rajratan , Kinnamon Daniel , Garvey Alfred
Published: May 2015

A nematic liquid crystal (LC) is doped with dilute concentrations of pristine monolayer graphene (GP) flakes, and the LC + GP hybrids are found to exhibit a dramatic increase in the dielectric anisotropy. Electric field-dependent conductance studies reveal that the graphene flakes follow the nematic director that mechanically rotates on increasing an applied electric field. Further studies show that the π–π electron stacking, between the graphene's honeycomb structure and the LC's benzene rings, stabilizes pseudo-nematic domains that collectively amplify the dielectric anisotropy by improving the orientational order parameter in the nematic phase. These anisotropic domains interact with the external electric field, resulting in a nonzero dielectric anisotropy in the isotropic phase as well. The enhancement in dielectric anisotropy, due to the LC–graphene coupling, is found to have subsequent positive impacts on the LC's orientational threshold field and elasticity that allows the nematic director to respond quicker on switching the electric field off.
Impact of varying buffer thickness generated strain and threading dislocations on the formation of plasma assisted MBE grown ultra-thin AlGaN/GaN heterostructure on silicon
Authors: Chowdhury Subhra , Biswas Dhrubes
Published: May 2015

Plasma-assisted molecular beam epitaxy (PAMBE) growth of ultra-thin Al0.2Ga0.8N/GaN heterostructures on Si(111) substrate with three buffer thickness (600 nm/400 nm/200 nm) have been reported. An unique growth process has been developed that supports lower temperature epitaxy of GaN buffer which minimizes thermally generated tensile strain through appropriate nitridation and AlN initiated epitaxy for achieving high quality GaN buffer which supports such ultra-thin heterostructures in the range of 10-15Å. It is followed by investigations of role of buffer thickness on formation of ultra-thin Al0.2Ga0.8N/GaN heterostructure, in terms of stress-strain and threading dislocation (TD). Structural characterization were performed by High-Resolution X-Ray Diffraction (HRXRD), room-temperature Photoluminescence (RT-PL), High Resolution Transmission Electron Microscopy (HRTEM) and Atomic Force Microscopy (AFM). Analysis revealed increasing biaxial tensile stress of 0.6918 ± 0.04, 1.1084, 1.1814 GPa in heterostructures with decreasing buffer thickness of 600, 400, 200 nm respectively which are summed up with residual tensile strain causing red-shift in RT-PL peak. Also, increasing buffer thickness drastically reduced TD density from the order 1010 cm−2 to 108 cm−2. Surface morphology through AFM leads to decrease of pits and root mean square value with increasing buffer thickness which are resulted due to reduction of combined effect of strain and TDs.
Captive management and the maintenance of genetic diversity in a vulnerable marsupial, the greater bilby
Authors: Miller Emily J. , Eldridge Mark D. B. , Morris Keith , Thomas Neil , Herbert Catherine A.
Published: May 2015

The endemic Australian greater bilby (Macrotis lagotis) is a vulnerable and iconic species. It has declined significantly due to habitat loss, as well as competition and predation from introduced species. Conservation measures include a National Recovery Plan that incorporates several captive breeding programs. Two of these programs were established within 12 months of one another (1997/98), with the same number and sex ratio of founding individuals, but executed different breeding strategies: (1) unmanipulated mating in semi–free range natural habitat versus (2) minimising mean kinship in large enclosures, with the supplementation of new individuals into both populations. This study evaluates the long-term genetic impact of these programs and examines the congruency between the pedigree studbook estimates of diversity and molecular data. Our data demonstrate that genetic diversity was maintained in both populations, with the supplementation of new individuals contributing to the gene pool. The studbook estimates of diversity and inbreeding are not consistent with the microsatellite data and should not solely be relied upon to evaluate the genetic health of captive populations. Our analyses suggest that captive breeding programs may not require costly and intensive management to effectively maintain long-term genetic diversity in a promiscuous species.
Current perspective on produced water management challenges during hydraulic fracturing for oil and gas recovery
Authors: Gregory Kelvin , Mohan Arvind Murali
Published: May 2015

Environmental context
There is growing worldwide interest in the production of oil and gas from deep, shale formations following advances in the technical expertise to exploit these resources such as hydraulic fracturing (fracking). The potential widespread application of hydraulic fracturing has raised concerns over deleterious environmental impacts on fragile water resources. We discuss the environmental management challenges faced by the oil and gas industry, and the opportunities for innovation in the industry.

Abstract
The need for cheap and readily available energy and chemical feedstock, and the desire for energy independence have spurred worldwide interest in the development of unconventional oil and gas resources; in particular, the production of oil and gas from shale formations. Although these resources have been known for a long time, the technical expertise and market forces that enable economical development has coincided over the last 15 years. The amalgamation of horizontal drilling and hydraulic fracturing have enabled favourable economics for development of fossil energy from these unconventional reservoirs, but their potential widespread application has raised concerns over deleterious environmental impacts on fragile water resources. The environmental management challenges faced by the oil and gas industry arise from local water availability and infrastructure for treating and disposing of the high-strength wastewater that is produced. Although there are significant challenges, these create opportunities for innovation in the industry.
UV radiation effects on the embryos of anchoveta (Engraulis ringens) and common sardine (Strangomera bentincki) off central Chile
Authors: Vásquez P. , Llanos-Rivera A. , Castro L. R. , Fernandez C.
Published: May 2015

It has been proposed that current levels of ultraviolet B (UVB) radiation could cause lethal or sublethal effects on fish embryos located in the upper layers of the water column. Observed levels of UVB off central Chile (36°S, 73°W) indicate that planktonic fish embryos could be exposed to harmful UVB radiation. From July 2011 to January 2012 embryos from anchoveta (Engraulis ringens) and common sardine (Strangomera bentincki) were used to test experimentally whether the UVB levels in central Chile produce lethal or sublethal effects in epipelagic fish embryos. Simultaneously, whether the embryos might be exposed to harmful UVB levels in the field was investigated. Our experimental results show that UVB may cause a decrease in hatching success, changes in buoyancy and embryonic malformations. These results, along with the observed vertical distribution of embryos and UVB radiation levels in the field during late spring suggest that lethal and sublethal effects may be occurring in the embryos of both species.
The effect of changing land use on the availability of potential nest trees for the endangered Muir's corella (Cacatua pastinator pastinator): a case study of the establishment of commercial Tasmanian blue gum plantations in Western Australia
Authors: Mawson P. R. , Cooper C. E.
Published: May 2015

In the mid-1990s commercial Tasmanian blue gum (Eucalyptus globulus) plantations were established in south-west Western Australia. We examined the extent of loss of potential nesting trees for an endangered obligate hollow-nesting cockatoo, Muir’s corella (Cacatua pastinator pastinator), resulting from establishment of these plantations during 1995–2004. Clearing of native vegetation was extensive in both Tonebridge (51%) and Frankland (76%) study sites. The proportion of land used for timber plantation increased significantly from 2.4% to 12.1% (Tonebridge) and 0.5% to 9% (Frankland) in the period 1995–2004. Plantations were predominantly established on already cleared farmland, but during the rapid development of plantations, large numbers of remnant paddock trees (mean = 56%) in cleared farmland were removed. Despite the loss of more than 50% of potential nesting habitat over an area of 376km2 within its current distribution, Muir’s corella continued to increase in numbers. However, there are concerns about delayed impacts of the clearing of potential nest trees we have observed, and consequences of further tree loss during future plantation harvesting. Evidence-based demonstration of biodiversity protection is increasingly needed to fulfil forest and plantation stewardship requirements, so greater care needs to be directed towards the management of extant remnant vegetation in paddocks.
Preferential flow paths in two alluvial soils with long-term additions of pig slurry in the Mediterranean zone of Chile
Authors: Fuentes Ignacio , Casanova Manuel , Seguel Oscar , Padarian José , Nájera Francisco , Salazar Osvaldo
Published: May 2015

Spatial variability of soil hydraulic properties helps to understand the complexity and dynamic patterns of solute distributions in soils. This study assessed the effects of slurry additions and soil physical properties on preferential flow and nitrate concentrations in two Mediterranean soils of central Chile under conventional agriculture management with long-term slurry additions. Two alluvial basins continuously cropped with maize (Zea mays) were selected, Pichidegua (Mollic Xerofluvent) and San Pedro (Fluventic Humixerept). Soils that had been amended with pig slurry were compared with unamended controls. Soil texture, bulk density, particle density, organic matter, porosity and hydraulic conductivity (Ks) were measured. Soil nitrate concentrations at different depths were determined every 2 weeks during the study, and a dye tracer test using Brilliant Blue FCF was conducted on each soil. Digital picture analysis was then performed to classify flow types in the soil profiles through the distribution of stained path width.
Stained path width allowed classification of soil flow types. Preferential flow showed no evidence of being affected by pig slurry; the stained patterns were mainly explained by tillage and soil physical properties, such as texture and Ks. Matrix flow-types in the first horizon grading to macropore flow-types at depth characterised all profiles, except San Pedro amended soil, where homogeneous matrix flow dominated through the entire profile. Concentrations of nitrate showed temporal variation during the measurement season, mainly due to the mineralisation–immobilisation budget and leaching, both triggered by Mediterranean climate conditions. Physical properties helped to explain nitrate distribution in the studied soils.
How to snap your cat: optimum lures and their placement for attracting mammalian predators in arid Australia
Authors: Read J. L. , Bengsen A. J. , Meek P. D. , Moseby K. E.
Published: May 2015

Context Automatically activated cameras (camera traps) and automated poison-delivery devices are increasingly being used to monitor and manage predators such as felids and canids. Maximising visitation rates to sentry positions enhances the efficacy of feral-predator management, especially for feral cats, which are typically less attracted to food-based lures than canids. Aims The influence of camera-trap placement and lures were investigated to determine optimal monitoring and control strategies for feral cats and other predators in two regions of semi-arid South Australia. Methods We compared autumn and winter capture rates, activity patterns and behaviours of cats, foxes and dingoes at different landscape elements and with different lures in three independent 6 km × 3 km grids of 18 camera-trap sites. Key results Neither visual, olfactory or audio lures increased recorded visitation rates by any predators, although an audio and a scent-based lure both elicited behavioural responses in predators. Cameras set on roads yielded an eight times greater capture rate for dingoes than did off-road cameras. Roads and resource points also yielded highest captures of cats and foxes. All predators were less nocturnal in winter than in autumn and fox detections at the Immarna site peaked in months when dingo and cat activity were lowest. Conclusions Monitoring and management programs for cats and other predators in arid Australia should focus on roads and resource points where predator activity is highest. Olfactory and auditory lures can elicit behavioural responses that render cats more susceptible to passive monitoring and control techniques. Dingo activity appeared to be inversely related to fox but not cat activity during our monitoring period. Implications Optimised management of feral cats in the Australian arid zone would benefit from site- and season-specific lure trials.
Arabic sign design
Authors: Petretta Julia
Published: May 2015

In the Middle East, the Arabic script is omnipresent and has an ample impact on the built environment. The calligraphic Arabic script is extremely flexible, making its text representation economic. However, in physical signs, calligraphy is replaced by Arabic typography, whose type choices may not capture the full flexibility of the Arabic script. Additionally, the graphic logic of dual language sign systems is not as straightforward when applied in Arabic, since the Arabic reads in two directions: right to left for the script and left to right for the numerals. Multi-script signage involving Arabic requires a heightened sensitivity regarding the information sequence.
Expletives in words
Authors: Okubo Tatsuhiro
Published: May 2015

The presence of semantically empty morphs (linking elements) in compounds poses a challenge for morpheme-based morphology. The purpose of this paper is to solve the problem using Distributed Morphology, which is a highly articulated version of morpheme-based morphology. Specifically, exploiting the empirical similarities between linking elements and expletives, I argue that linking elements are expletives in word domains. Moreover, I demonstrate that the Single Engine Hypothesis of Distributed Morphology theoretically supports the view of linking elements as expletives. In my analysis, linking elements function as markers of wordhood, just as phrasal expletives are markers of phrasehood. I confirm this view by showing that linking elements/expletives occur in all types of compounds.
Does morphology play a role in L2 processing?
Authors: Voga Madeleine , Anastassiadis-Syméonidis Anna , Giraudo Hélène
Published: May 2015

Two masked priming experiments with Greek advanced ESL speakers were run in order to reproduce the experiments reported by Silva & Clahsen (2008): our data yielded similar derivational priming but divergent results for inflectional priming. After comparing the two sets of results and examining some discrepancies between the two studies, we provide an interpretation outside the decompositional framework: morphological priming effects are not viewed as low level perceptual saliency effects but rather as the result of the form-meaning systematic relations.
Growth Inhibition of Bacterial Fish Pathogens and Quorum-Sensing Blocking by Bacteria Recovered from Chilean Salmonid Farms
Authors: Fuente Mery , Miranda Claudio D. , Jopia Paz , González-Rocha Gerardo , Guiliani Nicolás , Sossa Katherine , Urrutia Homero
Published: May 2015

The main goal of this study was to find bacterial isolates with the ability to inhibit the growth of the fish pathogens Aeromonas hydrophila, Vibrio anguillarum, and Flavobacterium psychrophilum and to inhibit the blockage of the quorum-sensing (QS) system. A total of 80 gram-negative strains isolated from various freshwater Chilean salmonid farms were studied. We determined that 10 strains belonging to the genus Pseudomonas inhibited at least one of the assayed fish pathogens. Of these, nine strains were able to produce siderophores and two strains were able to inhibit the growth of all assayed pathogenic species. When the 80 strains were examined for QS-blocking activity, only the strains Pseudomonas sp. FF16 and Raoultella planticola R5B1 were identified as QS blockers. When the QS-blocker strains were analyzed for their ability to produce homoserine lactone (HSL) molecules, thin-layer chromatography analysis showed that both strains were able to produce C6-HSL– and C8-HSL–type molecules. Strain R5B1 did not show growth inhibition properties, but strain FF16 also led to inhibition of growth in A. hydrophila and F. psychrophilum as well as to siderophore production. Pseudomonas sp. FF16 exhibited potentially useful antagonistic properties and could be a probiotic candidate for the salmon farming industry.

Received July 31, 2014; accepted December 17, 2014
Chitosan Influences the Expression of P-gp and Metabolism of Norfloxacin in Grass Carp
Authors: Hu Kun , Xie Xinyan , Zhao Yi-Ni , Li Yi , Ruan Jiming , Li Hao-Ran , Jin Tianyi , Yang Xian-Le
Published: May 2015

The aim of this study was to investigate the relationship between the administration of chitosan (CTS), expression of permeability glycoprotein (P-gp), and the metabolism of norfloxacin (NOR) in Grass Carp Ctenopharyngodon idella. Fish were administrated with a single dose of either NOR, CTS, 1:5 NOR–CTS or 1:10 NOR–CTS. The P-gp expression was analyzed by immunohistochemistry and real time-PCR. The concentration of NOR was determined using HPLC. The mRNA and protein expression of P-gp in the fish intestine was significantly enhanced following a single dosage of 40 mg/kg NOR, and peak expression occurred at 3 h after drug administration (P < 0.05). A single dosage of both 1:5 NOR–CTS and 1:10 NOR–CTS reduced the intestinal P-gp expression to levels significantly lower than that from NOR alone (P < 0.05), but significantly higher than that from the control (P < 0.05). Interestingly, CTS alone also led to a slight decrease in P-gp expression. In addition, pharmacokinetic assays revealed a marked increase in area under the curve (AUC) of NOR with 1:5 and 1:10 NOR–CTS, by approximately 1.5-fold and threefold, respectively. Finally, the relative bioavailability of NOR after a single oral dosage of 1:5 and 1:10 NOR–CTS was enhanced to 148.02% and 304.98%, respectively. In this study, we demonstrated that the transmembrane glycoprotein P-gp regulates NOR metabolism in the intestine of Grass Carp, suggesting that NOR may be a direct substrate of P-gp. More importantly, we showed that CTS can inhibit P-gp expression in a dose-dependent manner and improve the relative bioavailability of NOR in this species.

Received August 25, 2014; accepted November 12, 2014
Spirituality and entrepreneurial failure
Authors: Singh Smita , Corner Patricia Doyle , Pavlovich Kathryn
Published: May 2015

The paper examines how spirituality, an inner awareness especially of a greater force or power beyond the individual self, affected entrepreneurs’ experience of an important but under-researched part of the entrepreneurial process – venture failure. We implement a qualitative,
narrative research design and present a collective narrative of nine entrepreneurs whose spirituality played a role in experiencing venture failure. Unexpectedly, findings revealed entrepreneurs engaging deeply with failure instead of indulging in the self-deception and denial suggested by
research that applies psychological theories to venture failure. Furthermore, findings provided a rare, positive outcome from failure – entrepreneurs’ spirituality deepened through experiencing this negative life event. Finally, results indicate how spirituality influenced entrepreneurs’
decisions about founding future ventures after failure.
Improved photovoltaic and grain boundary characteristics of single elementary target-sputtered Cu2ZnSnSe4 thin films by post sulfurization/selenization process
Authors: Jo Yeon Hwa , Jang Jin Woo , Mohanty Bhaskar Chandra , Kang Han Byul , Cho Yong Soo
Published: May 2015

A potential way to improve the quality of Cu2ZnSnSe4 absorber thin film by a one step process of sputtering using a single elementary target is proposed for thin film solar cells. As critical parameters, different S/Se ratios and grain boundary characteristics are achieved by adjusting sequential sulfurization and selenization post-treatment. The simple sulfurization of as-deposited film at 530 °C in H2S is not effective in raising the performance but the additional Se annealing at a shorter duration of 5 min improves conversion efficiency from 0.12 to 3.21% with a drastic increase of the open circuit voltage. Positively-charged grain boundaries with narrow potential peaks seem to play a critical role for effective exciton separation and higher efficiency. The improvement is also understood as related to well-defined microstructures and the variable optical band gap.
Non-autonomous conformal iterated function systems and Moran-set constructions
Authors: Rempe-Gillen Lasse , Urbański Mariusz
Published: May 2015

We study non-autonomous conformal iterated function systems with finite or countable infinite alphabet alike. These differ from the usual (autonomous) iterated function systems in that the contractions applied at each step in time are allowed to vary. (In the case where all maps are affine similarities, the resulting system is also called a “Moran set construction”.)

We shall show that, given a suitable restriction on the growth of the number of contractions used at each step, the Hausdorff dimension of the limit set of such a system is determined by an equation known as Bowen’s formula. We also give examples that show the optimality of our results.

In addition, we prove Bowen’s formula for a class of infinite alphabet-systems and deal with Hausdorff measures for finite systems, as well as continuity of topological pressure and Hausdorff dimension for both finite and infinite systems. In particular we strengthen the existing continuity results for infinite autonomous systems.

As a simple application of our results, we show that, for a transcendental meromorphic function

f
f

, the Hausdorff dimension of the set of transitive points (i.e., those points whose orbits are dense in the Julia set) is bounded from below by the hyperbolic dimension of

f
f

.
The Omega myth: what really drives lower calcification rates in an acidifying ocean
Authors: Cyronak Tyler , Schulz Kai G. , Jokiel Paul L.
Published: May 2015

The literature on ocean acidification (OA) contains a prevalent misconception that reduced organismal calcification rates in an acidifying ocean are driven by a reduction in carbonate ion (CO32−) substrate availability (e.g. Omega or Ω). However, recent research in diverse organisms suggests that a reduction in seawater pH (i.e. increasing proton concentrations, [H+]) is the most likely driver of reduced calcification rates in these organisms. OA leads to higher [H+] in seawater which alters the proton gradient between internal cellular reservoirs and external bulk seawater, making it difficult for organisms to maintain pH homeostasis. Biologically mediated calcification is a complex process, so it is unlikely that simple CO32− substrate limitation is responsible for the observed decreases in calcification rates under OA conditions. Despite these inherent complexities, current predictions concerning the fate of calcifying organisms in an acidifying ocean have relied on the relationship between calcification rates and Ω. To more accurately predict how OA will affect the calcification of marine organisms, and consequently the global carbon cycle, we need to further elucidate the mechanisms driving observed decreases in calcification under acidified conditions.
Toward a high-performance management system in health care, part 4
Authors: McAlearney Ann Scheck , Hefner Jennifer , Robbins Julie , Garman Andrew N.
Published: May 2015

Background:

Central line-associated bloodstream infections (CLABSIs) are among the most harmful health care-associated infections and a major patient safety concern. Nationally, CLABSI rates have been reduced through the implementation of evidence-based interventions; thus far, however, hospitals still differ substantially in their success implementing these practices. Prior research on high-performance work practices (HPWPs) suggests that these practices may explain some of the differences health systems experience in the success of their quality improvement efforts; however, these relationships have not yet been systematically investigated.

Purposes:

In this study, we sought to explore the potential role HPWPs may play in explaining differences in the success of CLABSI reduction efforts involving otherwise similar organizations and approaches.

Methodology/Approach:

To form our sample, we identified eight hospitals participating in the federally funded “On the CUSP: Stop BSI” initiative. This sample included four hospital “pairs” matched on organizational characteristics (e.g., state, size, teaching status) but having reported contrasting CLABSI reduction outcomes. We collected data through site visits as well as 194 key informant interviews, which were framed using an evidence-informed model of health care HPWPs.

Findings:

We found evidence that, at higher performing sites, HPWPs facilitated the adoption and consistent application of practices known to prevent CLABSIs; these HPWPs were virtually absent at lower performing sites. We present examples of management practices and illustrative quotes categorized into four HPWP subsystems: (a) staff engagement, (b) staff acquisition/development, (c) frontline empowerment, and (d) leadership alignment/development.

Practice Implications:

We present the HPWP model as an organizing framework that can be applied to facilitate quality and patient safety efforts in health care. Managers and senior leaders can use these four HPWP subsystems to select, prioritize, and communicate about management practices critical to the success of their CLABSI prevention efforts.
Curbing Inappropriate Usage of STAT Imaging at a Large Academic Medical Center
Authors: Harvey H. Benjamin , Alkasab Tarik K. , Stingley Preston D. , Shore Mary T. , Abedi-Tari Faezeh , Abujudeh Hani H. , Meyersohn Nandini M. , Zhao Jong , Pandharipande Pari V. , Rosenthal Daniel I.
Published: May 2015

Purpose

To evaluate a new system for processing and performing inpatient STAT diagnostic imaging with respect to utilization and time-based performance metrics.

Materials and Methods

This HIPAA-compliant study had institutional review board approval; informed consent was not required. The radiology information system of a large academic medical center was queried for all inpatient diagnostic imaging exams performed and interpreted from August 1, 2010, to October 31, 2012. Using customized software, data were evaluated based on order priority (non-STAT or STAT) and exam modality with respect to exam volume and time-based performance metrics (time-to-performance and preliminary interpretation time). Data were compared over 3 periods: August 1, 2010, to October 31, 2010 (preimplementation period); November 1, 2010, to October 31, 2011 (year 1 postimplementation); and November 1, 2011, to October 31, 2012 (year 2 postimplementation).

Results

In the first year after implementation of the new STAT policy, the percentage of inpatient exams ordered STAT significantly decreased from 22.1% to 5.4% (P < 0.001). This represented a proportional decrease of 26% (CT), 16% (MRI), 20% (US), and 24% (radiographs) relative to pre-STAT policy levels. The median time-to-performance and median preliminary interpretation time significantly decreased for all modalities after implementation of the policy (P < 0.05 for all modalities), decreasing by an average of 104 and 162 minutes, respectively. These changes persisted throughout year 2 postimplementation.

Conclusion

A new institutional system for handling inpatient STAT diagnostic imaging results in a decreased number of STAT exams ordered and improved time-based performance metrics, thereby increasing workflow efficiency.
Pseudomonas coleopterorum sp. nov., a cellulase-producing bacterium isolated from the bark beetle Hylesinus fraxini
Authors: Menéndez Esther , Ramírez-Bahena Martha H. , Fabryová Anna , Igual José M. , Benada Oldrich , Mateos Pedro F. , Peix Alvaro , Kolařík Miroslav , García-Fraile Paula
Published: May 2015

We isolated a strain coded Esc2AmT during a study focused on the microbial diversity of adult specimens of the bark beetle Hylesinus fraxini. Its 16S rRNA gene sequence had 99.4 % similarity with respect to its closest relative, Pseudomonas rhizosphaerae IH5T. The analysis of partial sequences of the housekeeping genes rpoB, rpoD and gyrB confirmed that strain Esc2AmT formed a cluster with P. rhizosphaerae IH5T clearly separated from the remaining species of the genus Pseudomonas. Strain Esc2AmT had polar flagella and could grow at temperatures from 4 °C to 30 °C. The respiratory quinone was Q9 and the main fatty acids were C16 : 0, C18 : 1ω7c and/or C18 : 1ω6c in summed feature 8 and C16 : 1ω7c and/or C16 : 1ω6c in summed feature 3. DNA–DNA hybridization results showed 51 % relatedness with respect to P. rhizosphaerae IH5T. Oxidase, catalase and urease-positive, the arginine dihydrolase system was present but nitrate reduction and β-galactosidase production were negative. Aesculin hydrolysis was positive. Based on the results from the genotypic, phenotypic and chemotaxonomic analyses, we propose the classification of strain Esc2AmT as representing a novel species of the genus Pseudomonas, for which we propose the name Pseudomonas coleopterorum sp. nov. The type strain is Esc2AmT ( = LMG 28558T = CECT 8695T).
Genome-based taxonomic framework for the class Negativicutes: division of the class Negativicutes into the orders Selenomonadales emend., Acidaminococcales ord. nov. and Veillonellales ord. nov.
Authors: Campbell Chantal , Adeolu Mobolaji , Gupta Radhey S.
Published: May 2015

The classNegativicutesis currently divided into one order and two families on the basis of 16S rRNA gene sequence phylogenies. We report here comprehensive comparative genomic analyses of the sequenced members of the classNegativicutesto demarcate its different evolutionary groups in molecular terms, independently of phylogenetic trees. Our comparative genomic analyses have identified 14 conserved signature indels (CSIs) and 48 conserved signature proteins (CSPs) that either are specific for the entire class or differentiate four main groups within the class. Two CSIs and nine CSPs are shared uniquely by all or most members of the classNegativicutes, distinguishing this class from all other sequenced members of the phylumFirmicutes. Four other CSIs and six CSPs were specific characteristics of the familyAcidaminococcaceae, two CSIs and four CSPs were uniquely present in the familyVeillonellaceae, six CSIs and eight CSPs were found only inSelenomonasand related genera, and 17 CSPs were identified uniquely inSporomusaand related genera. Four additional CSPs support a pairing of the groups containing the generaSelenomonasandSporomusa. We also report detailed phylogenetic analyses for theNegativicutesbased on core protein sequences and 16S rRNA gene sequences, which strongly support the four main groups identified by CSIs and by CSPs. Based on the results from different lines of investigation, we propose a division of the classNegativicutesinto an emended orderSelenomonadalescontaining the new familiesSelenomonadaceaefam. nov. andSporomusaceaefam. nov. and two new orders,Acidaminococcalesord. nov. andVeillonellalesord. nov., respectively containing the familiesAcidaminococcaceaeandVeillonellaceae.
Brassicibacter thermophilus sp. nov., a thermophilic bacterium isolated from coastal sediment
Authors: Wang Bing , Ji Shi-Qi , Tian Xin-Xin , Qu Ling-Yun , Li Fu-Li
Published: May 2015

A novel thermophilic, obligately anaerobic bacterium, strain Cel2fT, was isolated from a cellulolytic community enriched from coastal marine sediment. Cells were Gram-stain-negative, non-motile, non-spore-forming and rod-shaped. Optimal growth temperature and pH of strain Cel2fTwere 55 °C and pH 7.0, respectively. NaCl was essential for the growth of strain Cel2fTand the strain showed enhanced growth in the presence of sea salt; the optimum sea salt concentration for growth was 7 % (w/v). Thiosulfate, sulfate and sulfite were potential electron acceptors. The major fatty acids of strain Cel2fTwere iso-C15 : 0, C16 : 0, and C18 : 0. Polar lipid analysis indicated the presence of phosphatidylethanolamine and phosphatidylglycerol. Strain Cel2fTcontained menaquinone MK-7 as the isoprenoid quinone, and the DNA G+C content was 31.3 mol%. Phylogenetic analysis revealed that the nearest relative of strain Cel2fTwasBrassicibacter mesophilusBMTwith 93.8 % 16S rRNA gene sequence similarity. Based on phenotypic, chemotaxonomic and phylogenetic characteristics, strain Cel2fTrepresents a novel species of genusBrassicibacter, for which the nameBrassicibacter thermophilussp. nov. is proposed. The type strain is Cel2fT( = JCM 30480T = CGMCC 1.5200T).
In VivoBlunt-End Cloning Through CRISPR/Cas9-Facilitated Non-Homologous End-Joining
Authors: Geisinger Jonathan M. , Turan Sören , Hernandez Sophia , Spector Laura P. , Calos Michele P.
Published: May 2015

The ability to precisely modify the genome in a site-specific manner is extremely useful. The CRISPR/Cas9 system facilitates precise modifications by generating RNA-guided double-strand breaks. We demonstrate that guide RNA pairs generate deletions that are repaired with a high level of precision by non-homologous end-joining in mammalian cells. We present a method called knock-in blunt ligation for exploiting this excision and repair to insert exogenous sequences in a homology-independent manner without loss of additional nucleotides. We successfully utilize this method in a human immortalized cell line and induced pluripotent stem cells to insert fluorescent protein cassettes into various loci, with efficiencies up to 35.8% in HEK293 cells. We also present a version of Cas9 fused to the FKBP12-L106P destabilization domain for investigating repair dynamics of Cas9-induced double-strand breaks. Ourin vivoblunt-end cloning method and destabilization-domain-fused Cas9 variant increase the repertoire of precision genome engineering approaches.
Pseudotime estimation: deconfounding single cell time series
Authors: Reid John , Wernisch Lorenz
Published: May 2015

Cross-sectional time series single cell data confound several sources of variation, with contributions from measurement noise, stochastic cell to cell variation and cell progression at different rates. Time series from single cell assays are particularly susceptible to confounding as the measurements are not averaged over populations of cells. When several genes are assayed in parallel these effects can be estimated and corrected for under certain smoothness assumptions on cell progression. We present a principled probabilistic model with a Bayesian inference scheme to analyse such data. We demonstrate our method’s utility on public microarray, nCounter and RNA-seq data sets from three organisms. Our method almost perfectly recovers withheld capture times in anArabidopsisdata set, it accurately estimates cell cycle peak times in a human prostate cancer cell line and it correctly identifies two precocious cells in a study of paracrine signalling in mouse dendritic cells. Furthermore, our method compares favourably with Monocle, a state-of-the-art technique. We also show using held out data that uncertainty in the temporal dimension is a common confounder and should be accounted for in analyses of cross-sectional time series.
Crystal structure of 1-[(6-chloropyridin-3-yl)sulfonyl]-1,2,3,4-tetrahydroquinoline
Authors: Jeyaseelan S. , Rajegowda H. R. , Britto Dominic Rayan R. , Raghavendra Kumar P. , Palakshamurthy B. S.
Published: May 2015

The tetrahydropyridine ring of the quinoline system in the title compound, C14H13ClN2O2S, adopts a half-chair conformation with the bond-angle sum at the N atom being 350.0°. The dihedral angle between the least-squares planes of the two aromatic rings is 50.13 (11)°. In the crystal, inversion dimers linked by pairs of C—H...O hydrogen bonds generateR22(10) loops. Additional intermolecular C—H...O hydrogen bonds generateC(7) chains along [100].
Crystal structure of bis[μ-bis(diphenylphosphanyl)methane-κ2P:P′]-μ-chlorido-chlorido-1κCl-(1-phenylthiourea-2κS)disilver acetonitrile hemisolvate
Authors: Nimthong-Roldán Arunpatcha , Ratthiwal Janejira , Wattanakanjana Yupa
Published: May 2015

In the dinuclear title complex, [Ag2Cl2(C7H8N2S)(C25H22P2)2]·0.5CH3CN, each AgIion displays a distorted tetrahedral coordination geometry with two P atoms from two bis(diphenylphosphanyl)methane (dppm) ligands, one bridging chloride ion, one terminal chloride ion and one terminal S atom from theN,N′-phenylthiourea (ptu) ligand. The dppm ligands and the bridging chloride ion force the two Ag atoms into close proximity, with a short Ag...Ag separation of 3.2064 (2) Å. In the crystal, complex molecules are linked by N—H...Cl hydrogen bonds forming a dimer. The dimers are linkedviaweak C— H...Cl hydrogen bonds forming a two-dimensional supramolecular architecture in theyzplane. In addition, an intramolecular N—H...Cl hydrogen bond is observed.
Crystal structures and hydrogen bonding in the anhydrous tryptaminium salts of the isomeric (2,4-dichlorophenoxy)acetic and (3,5-dichlorophenoxy)acetic acids
Authors: Smith Graham , Lynch Daniel E.
Published: May 2015

The anhydrous salts of 2-(1H-indol-3-yl)ethanamine (tryptamine) with isomeric (2,4-dichlorophenoxy)acetic acid (2,4-D) and (3,5-dichlorophenoxy)acetic (3,5-D), both C10H13N2+·C8H5Cl2O3−[(I) and (II), respectively], have been determined and their one-dimensional hydrogen-bonded polymeric structures are described. In the crystal of (I), the aminium H atoms are involved in three separate inter-species N—H...O hydrogen-bonding interactions, two with carboxylate O-atom acceptors and the third in an asymmetric three-centre bidentate carboxylateO,O′chelate [graph setR12(4)]. The indole H atom forms an N—H...Ocarboxylatehydrogen bond, extending the chain structure along theb-axis direction. In (II), two of the three aminium H atoms are also involved in N—H...Ocarboxylatehydrogen bonds similar to (I) but with the third, a three-centre asymmetric interaction with carboxylate and phenoxy O atoms is found [graph setR12(5)]. The chain polymeric extension is also alongb. There are no π–π ring interactions in either of the structures. The aminium side-chain conformations differ significantly between the two structures, reflecting the conformational ambivalence of the tryptaminium cation, as found also in the benzoate salts.
Crystal structure of 4-chloro-2-{(E)-[(3,4-dimethylphenyl)imino]methyl}phenol
Authors: Salim Muhammad , Tahir Muhammad Nawaz , Munawar Munawar Ali , Shahid Muhammad , Shad Hazoor Ahmad
Published: May 2015

In the title compound, C15H14ClNO, which is isostructural with its bromo analogue [Tahiret al.(2012).Acta Cryst., E68, o2730], the dihedral angle between the planes of the aromatic rings is 2.71 (7)° and an intramolecular O—H...N hydrogen bond closes anS(6) ring. In the crystal, extremely weak C—H...π interactions link the molecules into a three-dimensional network.
Crystal structure of 2,2-dimethyl-N-(5-methylpyridin-2-yl)propanamide
Authors: El-Hiti Gamal A. , Smith Keith , Hegazy Amany S. , Alanazi Saud A. , Kariuki Benson M.
Published: May 2015

There are two molecules in the asymmetric unit of the title compound, C11H16N2O. The pyridine rings and amide groups overlap almost perfectly (r.m.s. overlay fit = 0.053 Å), but the tertiary butyl groups have different orientations: in one molecule, one of the methyl C atoms issynto the amide O atom [O—C—C—C = −0.8 (3)°] and in the other the equivalent torsion angle is 31.0 (2)°. In the crystal, the two independent molecules are linked by a pair of N—H...N hydrogen bonds in the form of anR22(8) loop to form a dimer. A C—H...O interaction connects the dimers into [100] chains.
Crystal structure of (4E)-4-(8-methoxy-2H-chromen-2-ylidene)-3-methyl-1-phenyl-1H-pyrazol-5(4H)-one
Authors: Salim Muhammad , Munawar Munawar Ali , Tahir Muhammad Nawaz , Shahid Muhammad , Malik Khizar Iqbal
Published: May 2015

In the title compound, C20H16N2O3, the phenyl substituent attached to the pyrazole ring makes a dihedral angle of 4.87 (7)° with the rest of the molecule. In the crystal, molecules are connected into inversion dimers of theR22(14) type by pairs of C—H...O interactions. π–π interactions exist between the benzene and pyrazole rings at a distance of 3.701 (1) Å. Similarly, π–π interactions are present at a centroid–centroid distance of 3.601 (1) Å between the oxygen-containing heterocyclic ring and methoxy substituted aromatic ring of a neighbouring molecule. Additional C—H...π and C=O...π interactions are also observed.