bluuebunny/crossref_metadata_2025_split huggingface dataset:
Small‐scale distribution of copper in a Technosol horizon studied by nano‐scale secondary ion mass spectrometry
Authors: Rennert Thilo , Höschen Carmen , Rogge Derek , Steffens Markus 
Published: March 2018

RationaleIn contaminated soil, copper (Cu) is commonly distributed among various very small particles. To enlighten the qualitative distribution of Cu in a contaminated Technosol (a soil developed from deposited technogenic material) on the sub‐micron scale, we used nano‐scale secondary ion mass spectrometry (NanoSIMS).MethodsWe studied seven areas (up to 40 μm × 40 μm) on a thin section of a soil horizon by NanoSIMS, measuring 12C−, 18O−, 32S−, 63Cu− and 56Fe16O−. We evaluated the NanoSIMS measurements with a novel digital image processing tool to enlighten the composition of measured areas and thus the distribution of Cu at the sub‐micron scale. Image processing comprised spatial and spectral smoothing, normalization, endmember extraction and supervised classification.ResultsCopper was present in all areas studied on the thin section in hotspots. 63Cu− was never the ion with the highest number of mean‐normalized counts (MNCs). In classes indicating Cu accumulation, Fe or S had the highest MNCs with mostly small values for O, pointing to the presence of Cu in sulfides. Copper adsorbed on Fe oxides was also indicated. Direct interaction of Cu with organic matter was less important. Copper‐containing minerals were rather adjacent to or surrounded by an organic matrix.ConclusionsThe combination of NanoSIMS analyses with digital image processing gave us new insights into the distribution of Cu in contaminated soil. We suggest this combination as a new powerful tool for the identification of ionic contaminants in soil and other solid phases in the environment.
Role of search for domain knowledge and architectural knowledge in alliance partner selection
Authors: Yayavaram Sai , Srivastava Manish K. , Sarkar MB 
Published: March 2018

Research Summary: The literature on technological alliances emphasizes that search for knowledge drives alliance formation. However, in conceptualizing technological knowledge, prior work on alliances has not made a distinction between domain knowledge—knowledge that firms possess in distinct technological domains—and architectural knowledge—knowledge that firms possess about how to combine elements from different technological domains. We argue that firms seek partners that are similar in domain knowledge to deepen their knowledge, and partners that are dissimilar in architectural knowledge to broaden their knowledge. Our results indicate that the likelihood of alliance formation increases when two firms are similar in domain knowledge and dissimilar in architectural knowledge. Further, our results show that these effects are positively moderated by the degree of decomposability of a firm's knowledge base.
Managerial Summary: In dynamic environments, companies need to continually deepen and broaden their technological knowledge, and they often look for alliance partners who can provide them that knowledge. For knowledge deepening, companies are more likely to form alliances with those companies that have expertise in similar technological fields. For knowledge broadening, they are more likely to form alliances with those companies that have expertise in the same technological fields, but have different recipes for combining knowledge from those fields. Furthermore, a company with a modular knowledge base is more likely to seek a partner that has expertise in similar technological fields or whose recipes for combining knowledge from different technological fields are different from the recipes it has.
Development and evaluation of a bait station for selectively dispensing bait to invasive wild pigs
Authors: Lavelle Michael J. , Snow Nathan P. , Halseth Joe M. , Kinsey John C. , Foster Justin A. , VerCauteren Kurt C. 
Published: March 2018

ABSTRACTPopulations of invasive wild pigs (Sus scrofa; hereafter, wild pigs) are expanding, requiring cost‐effective tools for control, and disease prevention, such as toxic or vaccine baits. Specifically, development of a novel and humane toxicant is underway for control of wild pigs in the United States and Australia. A species‐specific bait station for delivering the toxic bait must be used to protect nontarget animals. Further, a bait station must be designed to maximize feeding by wild pigs by accommodating their group‐feeding behaviors. We sought to develop a bait station that delivered bait to the maximum proportion of wild pigs and excluded the most ubiquitous nontarget species, specifically white‐tailed deer (Odocoileus virginianus) and raccoons (Procyon lotor). We used direct observations and cameras during 2015 to evaluate wild pig feeding behavior and nontarget access for various sizes, arrangements, and construction materials of prototype bait stations in pen and field settings in Texas, USA. We found that a bait station constructed of 2 back‐to‐back troughs, 1.1 m in length, without a divider was sufficient for feeding the largest proportion of wild pigs in pens. Using this design of bait station at 30 field sites, we found that wild pigs fed more frequently from plastic than metal bait stations, although both bait stations reduced feeding by wild pigs compared with control sites. From near‐video imagery at 3 field sites, we identified that 80% of wild pigs (33 of 41), 0% of white‐tailed deer (0 of 7), and 17% of raccoons (1 of 6) accessed the bait stations on the final night of testing following a 2‐week acclimation and training period. Future steps toward development of a wild pig‐specific bait station include adding resistance to the lids of bait stations to completely exclude raccoons and identify baiting strategies that most efficiently acclimate wild pigs to using bait stations. Published 2018. This article is a U.S. Government work and is in the public domain in the USA.
Structure of stable degeneration of K3 surfaces into pairs of rational elliptic surfaces
Authors: Kimura Yusuke 
Published: March 2018

Abstract

F-theory/heterotic duality is formulated in the stable degeneration limit of a K3 fibration on the F-theory side. In this note, we analyze the structure of the stable degeneration limit. We discuss whether stable degeneration exists for pairs of rational elliptic surfaces. We demonstrate that, when two rational elliptic surfaces have an identical complex structure, stable degeneration always exists. We provide an equation that systematically describes the stable degeneration of a K3 surface into a pair of isomorphic rational elliptic surfaces. When two rational elliptic surfaces have different complex structures, whether their sum glued along a smooth fiber admits deformation to a K3 surface can be determined by studying the structure of the K3 lattice. We investigate the lattice theoretic condition to determine whether a deformation to a K3 surface exists for pairs of extremal rational elliptic surfaces. In addition, we discuss the configurations of singular fibers under stable degeneration.
The sum of two isomorphic rational elliptic surfaces glued together admits a deformation to a K3 surface, the singular fibers of which are twice that of the rational elliptic surface. For special situations, singular fibers of the resulting K3 surface collide and they are enhanced to a fiber of another type. Some K3 surfaces become attractive in these situations. We determine the complex structures and the Weierstrass forms of these attractive K3 surfaces. We also deduce the gauge groups in F-theory compactifications on these attractive K3 surfaces times a K3. E
6, E
7, E
8, SU(5), and SO(10) gauge groups arise in these compactifications.
New nonperturbative scales and glueballs in confining supersymmetric gauge theories
Authors: Anber Mohamed M. , Poppitz Erich 
Published: March 2018

AbstractWe show that new nonperturbative scales exist in four-dimensional$$ \mathcal{N} $$N= 1 super-Yang-Mills theory compactified on a circle, with an iterated-exponential dependence on the inverse gauge coupling. The lightest states with the quantum numbers of four-dimensional glueballs are nonrelativistic bound states of dual Cartan gluons and superpartners, with binding energy equal to$$ {e}^{-{e}^{1/{g}^2}} $$e−e1/g2in units of the confining mass gap. Focusing on SU(2) gauge group, we construct the nonrelativistic effective theory, show that the lightest glueball/glueballino states fill a chiral supermultiplet, and determine their “doubly-nonperturbative” binding energy. The iterated-exponential dependence on the gauge coupling is due to nonperturbative couplings in the long distance theory,$$ \uplambda \sim {e}^{-\frac{1}{g^2}} $$λ∼e−1g2, which are responsible for attractive interactions, in turn producing exponentially small,$$ \sim {e}^{-\frac{1}{\lambda }} $$∼e−1λ, effects.
On classical de Sitter and Minkowski solutions with intersecting branes
Authors: Andriot David 
Published: March 2018

AbstractMotivated by the connection of string theory to cosmology or particle physics, we study solutions of type II supergravities having a four-dimensional de Sitter or Minkowski space-time, with intersectingDp-branes and orientifoldOp-planes. Only few such solutions are known, and we aim at a better characterisation. Modulo a few restrictions, we prove that there exists no classical de Sitter solution for any combination ofD3/O3andD7/O7, while we derive interesting constraints for intersectingD5/O5orD6/O6, or combinations ofD4/O4andD8/O8. Concerning classical Minkowski solutions, we understand some typical features, and propose a solution ansatz. Overall, a central information appears to be the way intersectingDp/Opoverlap each other, a point we focus on.
KLT-type relations for QCD and bicolor amplitudes from color-factor symmetry
Authors: Brown Robert W. , Naculich Stephen G. 
Published: March 2018

Abstract

Color-factor symmetry is used to derive a KLT-type relation for tree-level QCD amplitudes containing gluons and an arbitrary number of massive or massless quark-antiquark pairs, generalizing the expression for Yang-Mills amplitudes originally postulated by Bern, De Freitas, and Wong. An explicit expression is given for all amplitudes with two or fewer quark-antiquark pairs in terms of the (modified) momentum kernel.
We also introduce the bicolor scalar theory, the “zeroth copy” of QCD, containing massless biadjoint scalars and massive bifundamental scalars, generalizing the biadjoint scalar theory of Cachazo, He, and Yuan. We derive KLT-type relations for tree-level amplitudes of biadjoint and bicolor theories using the color-factor symmetry possessed by these theories.
Production of pikromycin using branched chain amino acid catabolism in Streptomyces venezuelae ATCC 15439
Authors: Yi Jeong Sang , Kim Minsuk , Kim Eun-Jung , Kim Byung-Gee 
Published: March 2018

Abstract
Branched chain amino acids (BCAA) are catabolized into various acyl-CoA compounds, which are key precursors used in polyketide productions. Because of that, BCAA catabolism needs fine tuning of flux balances for enhancing the production of polyketide antibiotics. To enhance BCAA catabolism for pikromycin production in Streptomyces venezuelae ATCC 15439, three key enzymes of BCAA catabolism, 3-ketoacyl acyl carrier protein synthase III, acyl-CoA dehydrogenase, and branched chain α-keto acid dehydrogenase (BCDH) were manipulated. BCDH overexpression in the wild type strain resulted in 1.3 fold increase in pikromycin production compared to that of WT, resulting in total 25 mg/L of pikromycin. To further increase pikromycin production, methylmalonyl-CoA mutase linked to succinyl-CoA production was overexpressed along with BCDH. Overexpression of the two enzymes resulted in the highest titer of total macrolide production of 43 mg/L, which was about 2.2 fold increase compared to that of the WT. However, it accumulated and produced dehydroxylated forms of pikromycin and methymycin, including their derivatives as well. It indicated that activities of pikC, P450 monooxygenase, newly became a bottleneck in pikromycin synthesis.
Exploring the Issues Surrounding Clinical Exome Sequencing in the Prenatal Setting
Authors: Narayanan Swetha , Blumberg Bruce , Clayman Marla L. , Pan Vivian , Wicklund Catherine 
Published: March 2018

AbstractExome sequencing is a clinical diagnostic test offered primarily for children and adults with suspected genetic conditions. The purpose of this study was to explore issues related to exome sequencing in a reproductive clinical setting. This was a qualitative study using semi‐structured interviews. Participants were professionals drawn from four key stakeholder groups—healthcare providers, laboratory/industry, ethics, and government. Transcribed interviews were analyzed for emergent themes. Most participants saw potential clinical utility in offering prenatal exome sequencing for diagnostic purposes as opposed to screening. Participants expressed similar challenges already encountered with using exome sequencing in a pediatric setting, such as difficulty interpreting results and voiced many of the same concerns posed by prenatal testing, such as adequate pretest counseling. While previously reported issues and challenges were mentioned, participants agreed those difficulties are anticipated to be much greater with prenatal exome sequencing because of the scope of testing and the option for pregnancy decision‐making. The results of this study help gain a better understanding of the implications of using exome sequencing in a prenatal setting. Development of guidelines is also warranted to aid clinical practice and laboratory standards for reporting prenatal results.
Xylem embolism refilling and resilience against drought‐induced mortality in woody plants: processes and trade‐offs
Authors: Klein Tamir , Zeppel Melanie J. B. , Anderegg William R. L. , Bloemen Jasper , De Kauwe Martin G. , Hudson Patrick , Ruehr Nadine K. , Powell Thomas L. , von Arx Georg , Nardini Andrea 
Published: March 2018

AbstractUnderstanding which species are able to recover from drought, under what conditions, and the mechanistic processes involved, will facilitate predictions of plant mortality in response to global change. In response to drought, some species die because of embolism‐induced hydraulic failure, whilst others are able to avoid mortality and recover, following rehydration. Several tree species have evolved strategies to avoid embolism, whereas others tolerate high embolism rates but can recover their hydraulic functioning upon drought relief. Here, we focus on structures and processes that might allow some plants to recover from drought stress via embolism reversal. We provide insights into how embolism repair may have evolved, anatomical and physiological features that facilitate this process, and describe possible trade‐offs and related costs. Recent controversies on methods used for estimating embolism formation/repair are also discussed, providing some methodological suggestions. Although controversial, embolism repair processes are apparently based on the activity of phloem and ray/axial parenchyma. The mechanism is energetically demanding, and the costs to plants include metabolism and transport of soluble sugars, water and inorganic ions. We propose that embolism repair should be considered as a possible component of a ‘hydraulic efficiency‐safety’ spectrum. We also advance a framework for vegetation models, describing how vulnerability curves may change in hydrodynamic model formulations for plants that recover from embolism.
Performance analysis of junctionless DG‐MOSFET‐based 6T‐SRAM with gate‐stack configuration
Authors: Tayal Shubham , Nandi Ashutosh 
Published: March 2018

In this work, the investigation of high‐K gate‐stack‐based junctionless (JL) double‐gate (DG) metal‐oxide‐semiconductor field‐effect transistor (MOSFET) is carried out to study the high‐K gate dielectric effect on six‐transistor (6T)‐static random‐access memory (SRAM) built with JLDG‐MOSFET. It is observed that the utilisation of the high‐K gate dielectric in JLDG‐MOSFETs improves the static noise margin (SNM) that is the stability of the cell as well as access time (AT) which reflects the delay performance of the SRAM cell. Furthermore, scaling down of Lg degrades the stability. Moreover, it is also described that the enhancement in hold SNM (ΔHSNM = HSNM(K =40) −HSNM(K =3.9)), read SNM (ΔRSNM = RSNM(K =40) −RSNM(K =3.9)), and write SNM (ΔWSNM = WSNM(K =40) −WSNM(K =3.9)) is restricted at lower Lg without much enhancement in the improvement of read AT and write AT. Therefore, it is appropriate to consider higher channel length (∼30 nm) while designing high‐K gate‐stacked‐based JLDG‐MOSFETs for the 6T‐SRAM cell.
Statistics of the polarized submillimetre emission maps from thermal dust in the turbulent, magnetized, diffuse ISM
Authors: Levrier F. , Neveu J. , Falgarone E. , Boulanger F. , Bracco A. , Ghosh T. , Vansyngel F. 
Published: March 2018

Context. The interstellar medium (ISM) is now widely acknowledged to display features ascribable to magnetized turbulence. With the public release of Planck data and the current balloon-borne and ground-based experiments, the growing amount of data tracing the polarized thermal emission from Galactic dust in the submillimetre provides choice diagnostics to constrain the properties of this magnetized turbulence. Aims. We aim to constrain these properties in a statistical way, focussing in particular on the power spectral index βB of the turbulent component of the interstellar magnetic field in a diffuse molecular cloud, the Polaris Flare.
Methods. We present an analysis framework based on simulating polarized thermal dust emission maps using model dust density (proportional to gas density nH) and magnetic field cubes, integrated along the line of sight (LOS), and comparing these statistically to actual data. The model fields are derived from fractional Brownian motion (fBm) processes, which allows a precise control of their one- and two-point statistics. The parameters controlling the model are (1)–(2) the spectral indices of the density and magnetic field cubes, (3)–(4) the RMS-to-mean ratios for both fields, (5) the mean gas density, (6) the orientation of the mean magnetic field in the plane of the sky (POS), (7) the dust temperature, (8) the dust polarization fraction, and (9) the depth of the simulated cubes. We explore the nine-dimensional parameter space through a Markov chain Monte Carlo analysis, which yields best-fitting parameters and associated uncertainties.
Results. We find that the power spectrum of the turbulent component of the magnetic field in the Polaris Flare molecular cloud scales with wavenumber as k−βB with a spectral index βB = 2.8 ± 0.2. It complements a uniform field whose norm in the POS is approximately twice the norm of the fluctuations of the turbulent component, and whose position angle with respect to the north-south direction is χ0 ≈−69°. The density field nH is well represented by a log-normally distributed field with a mean gas density 〈nH〉≈40 cm−3, a fluctuation ratio σnH/〈nH〉≈1.6, and a power spectrum with an index
βn=1.7−0.3+0.4. We also constrain the depth of the cloud to be d ≈ 13 pc, and the polarization fraction p0 ≈ 0.12. The agreement between the Planck data and the simulated maps for these best-fitting parameters is quantified by a χ2 value that is only slightly larger than unity.
Conclusions. We conclude that our fBm-based model is a reasonable description of the diffuse, turbulent, magnetized ISM in the Polaris Flare molecular cloud, and that our analysis framework is able to yield quantitative estimates of the statistical properties of the dust density and magnetic field in this cloud.
Epidemiology, Microbiological Diagnosis, and Clinical Outcomes in Pyogenic Vertebral Osteomyelitis: A 10-year Retrospective Cohort Study
Authors: Chong Brian S W , Brereton Christopher J , Gordon Alexander , Davis Joshua S 
Published: March 2018

Abstract

Background
Pyogenic vertebral osteomyelitis (PVO) is rising in incidence, but optimal methods of investigation and duration of antibiotic therapy remain controversial.

Methods
We conducted a single-center retrospective cohort study of PVO at an Australian teaching hospital. We included all adults with a first episode of PVO between 2006 and 2015. PVO was defined based on the presence of prespecified clinical and radiological criteria. The main exposures of interest were investigation strategy and antibiotic treatment. The main outcome measures were duration of hospital admission, mortality during index admission, symptom resolution during index admission, and attributable readmission within 2 years.

Results
Of 129 included patients, 101 (78%) had a causative organism identified. Patients with an identified pathogen were more likely to be febrile (75% compared with 29%, P &lt; .001) and had a higher mean admission C-reactive protein (207 vs 54, P &lt; .001) compared with patients without an identified pathogen. However, they were less likely to experience an adverse outcome (death or attributable readmission within 2 years; adjusted odds ratio, 0.36; 95% confidence interval, 0.13–0.99; P = .04). Open biopsy of vertebral tissue had a higher diagnostic yield (70%) than fine needle aspirate (41%) or core biopsy (30%). Despite receiving a median of 6 weeks of intravenous antibiotics, only 15% of patients had a full recovery on discharge from index admission.

Conclusions
Clinical outcomes for patients with PVO were poor. Obtaining a microbiological diagnosis is associated with a better outcome. However, prospective and randomized studies are essential to establishing optimal investigation and treatment pathways.
Spinal Cord Infarction in the Region of the Posterior Spinal Artery After Embolization for Vertebral Artery Dissection
Authors: Tsuruta Wataro , Yamamoto Tetsuya , Ikeda Go , Sato Masayuki , Ito Yoshiro , Takigawa Tomoji , Marushima Aiki , Nakai Yasunobu , Matsumaru Yuji , Matsumura Akira 
Published: March 2018

Abstract

BACKGROUND
Endovascular surgery for vertebral artery dissections (VADs) carries the risk of spinal cord infarction (SCI). Although SCI in the region of the anterior spinal artery (ASA) has been reported, SCI in the region of the posterior spinal artery (PSA) is rare.

OBJECTIVE
To investigate PSA infarction after endovascular surgery for VAD.

METHODS
Infarction in the region of the PSA after endovascular surgery for VADs carried out in consecutive 21 cases was investigated. The variables of aneurysmal location, status, intra-aneurysmal thrombosis, antithrombotic therapy, and endovascular procedure were investigated in relation to the occurrence of spinal cord or brain stem infarction.

RESULTS
Thirteen cases were unruptured aneurysms, and 8, ruptured aneurysms. The endovascular surgical method was internal trapping in 10 cases, stent-assisted coil embolization in 8 cases, and proximal occlusion (PO) in 3 cases. Periprocedural symptomatic infarction was detected in 4 of the 21 cases (19%): 3 SCIs and 1 lower medulla infarction, after 1 stent-assisted coil embolization and 3 PO. All 3 symptomatic SCIs were PSA infarction. On univariate analysis, the variables of posterior inferior cerebellar artery-involved-type, PO, and intraprocedural proximal flow arrest were significantly correlated with occurrence of PSA infarction.

CONCLUSION
PSA infarction after endovascular surgery for VAD seems not to be a rare potential complication. Insufficiency of collateral blood flow and artery-to-artery embolism due to intraprocedural flow stagnation of the VA seem to be the possible mechanisms of PSA infarction in addition to previously reported mechanisms such as direct obliteration by the embolic materials and extended thrombosis of the VA stump.