bluuebunny/crossref_metadata_2025 huggingface dataset:
Investigation of the disorder of Ga1–xAlxAs mixed crystals. Part I: Small concentrations
Authors: Berdekas D.
Published: February 2016

We present calculations of the Raman intensities scattered by the phonons of the mixed crystals Ga1–xAlxAs for five small concentrations up to x = 0.14, away from resonance conditions. Each mixed crystal is approached by a primitive cell, the volume of which is 64 times the volume of the bulk zincblende primitive cell. The phonons have been calculated using a version of a three‐dimensional Valence Overlap Shell Model (VOSM) and the Raman spectra with the bond‐polarizability model (BPM). The values of the bond‐polarizability (BP) parameters of Ga–As and Al–As bonds necessary for the calculation of the Raman intensities are, for the first time, not estimated arbitrarily, but we have evaluated them using certain relations involving directly measurable quantities. We also show that the frequencies of the AlAs LO(Γ)‐like modes and their Raman profiles and intensities as well, depend, for a given Al concentration, strongly on the way the cations are distributed over the mixed‐crystal cation planes. Concerning the GaAs LO(Γ)‐like modes, differences in the cation distribution affect only a little their frequencies and their intensities, but may result in pronounced left asymmetries of the profiles of the corresponding strong Raman peaks. The comparison between the calculated and the experimental Raman spectrum for the Ga0.86Al0.14As is very encouraging, especially when the mixed crystal is described by a disorder configuration where the Al ions are gathered to neighboring cation planes.
Distribution of the two‐sample t‐test statistic following blinded sample size re‐estimation
Authors: Lu Kaifeng
Published: February 2016

We consider the blinded sample size re‐estimation based on the simple one‐sample variance estimator at an interim analysis. We characterize the exact distribution of the standard two‐sample t‐test statistic at the final analysis. We describe a simulation algorithm for the evaluation of the probability of rejecting the null hypothesis at given treatment effect. We compare the blinded sample size re‐estimation method with two unblinded methods with respect to the empirical type I error, the empirical power, and the empirical distribution of the standard deviation estimator and final sample size. We characterize the type I error inflation across the range of standardized non‐inferiority margin for non‐inferiority trials, and derive the adjusted significance level to ensure type I error control for given sample size of the internal pilot study. We show that the adjusted significance level increases as the sample size of the internal pilot study increases. Copyright © 2016 John Wiley & Sons, Ltd.
Dynamical Core Model Intercomparison Project (DCMIP) tracer transport test results for CAM‐SE
Authors: Hall David M. , Ullrich Paul A. , Reed Kevin A. , Jablonowski Christiane , Nair Ramachandran D. , Tufo Henry M.
Published: February 2016

The Dynamical Core Model Intercomparison Project (DCMIP) provides a set of tests and procedures designed to facilitate development and intercomparison of atmospheric dynamical cores in general circulation models (GCMs). Test category 1 examines the advective transport of passive tracers by three‐dimensional prescribed wind velocity fields, on the sphere. These tests are applied to the Spectral Element (SE) dynamical core of the Community Atmosphere Model (CAM), the default for high‐resolution simulations in the Community Earth System Model (CESM). Test case results are compared with results from the CAM‐FV (Finite Volume) and MCore models where possible. This analysis serves both to evaluate the performance of CAM‐SE's spectral‐element tracer transport routines as well as to provide a baseline for comparison with other atmospheric dynamical cores and f or future improvements to CAM‐SE itself.
Testifying the digital artifacts for line application program under Mac OS X from the aspects of witness experts
Authors: Chu Hai‐Cheng , Chao Han‐Chieh
Published: February 2016

Unarguably, the physical memory acquisition of contemporary computing devices has been an extremely pivotal and indispensable errand for digital forensics specialists because of its volatility of the embedded data, which was deposited from related computing resources. Nowadays, hundreds of millions of global naive or sophisticated end users exploit LINE application program (AP) as the instant messaging toolkit to conduct real‐time communications including sending text messages or video clips. Unfortunately, this cutting‐edge innovation has been taken advantage by the cybercrime syndicates, terrorists, or the extremists to fulfill their lucrative purposes. Hence, this research provides generic research methodologies for digital forensics experts to conduct whenever digital artifacts become mandatory in order to disclose some cybercrimes or the noncompliance of computer usage concerning LINE AP especially for the witness experts to testify in a court of law. On the other hand, this research paper pinpoints the volatile raw memory contains valuable and imperceptive digital artifacts that could reflect the interactions when LINE AP was utilized under Mac OS X. Copyright © 2016 John Wiley & Sons, Ltd.
A comparison of ERBS spectra of compounds with Monte Carlo simulations
Authors: Vos M. , Marmitt G. G , Grande P. L.
Published: February 2016

Electron Rutherford backscattering measures the near‐surface composition of samples quantitatively. For interpretation, one usually relies on the single‐scattering approximation. Here, we present results for four compounds, containing oxygen and other species, varying from very light to very heavy. Two Monte Carlo codes are described that model these measurements. From these simulations, it is clear that for all samples, multiple scattering occurs frequently, but also that the single scattering interpretation deduces the right composition, except for O atoms in a very heavy matrix, where interpretation is more difficult. The intrinsic width of the peaks, a consequence of Doppler broadening due to the velocity of the (vibrating) atoms, turns out to be more sensitive to multiple scattering effects. Copyright © 2016 John Wiley & Sons, Ltd.
Surface characterization of textiles modified by copper and zinc oxide nano‐antimicrobials
Authors: Ditaranto N. , Picca R.A. , Sportelli M.C. , Sabbatini L. , Cioffi N.
Published: February 2016

Colloids of antimicrobial metal and metal oxide nanoparticles (NPs) were electrochemically prepared and then used as surface modifiers for industrial batches of textiles. Different surface loadings could be easily deposited on the surface of the products of interest in order to inhibit the growth of microbes such as bacteria. Surface chemical characterization was performed using X‐ray Photoelectron Spectroscopy technique to quantitatively assess the materials' surface chemical composition. Moreover, the NP chemical speciation was evaluated and correlated to the electrosynthesis characteristics, processing conditions, and textiles storage time. Atomic absorption spectroscopy was employed to quantify the metal ions release in a proper contact solution in order to correlate the surface and bulk availability of NPs with the antimicrobial efficacy. Promising spectroscopic results strongly support future real‐life applications in different fields. Copyright © 2016 John Wiley & Sons, Ltd.
ToF‐SIMS study of gilding technique in the fresco Vela della Castità by Giotto's school
Authors: Biocca P. , Santopadre P. , Sidoti G. , Sotgiu G. , de Notaristefani F. , Tortora L.
Published: February 2016

Time of flight secondary ion mass spectrometry (ToF‐SIMS) has become a fundamental analytical technique in cultural heritage studies to obtain the identification and distribution of organic components present in artworks. A sample taken from the soldier's golden shield decoration in the fresco Vela della Castità (San Francesco Lower Basilica, Assisi) was studied. The metal leaves for gilding decoration on wall paintings are usually applied using an oil‐resin mordant as adhesive. In this work, organic and inorganic compounds used in this peculiar painting technique were identified by ToF‐SIMS technique. High mass resolution spectrometry was applied for the chemical characterization of organic materials present in oil‐resin binding media and red lake paint layer. Presence of azelaic, palmitic and stearic acids proved the nature of the oil binder between plaster and tin leaf and between tin and gold leaf. The analyses revealed also the presence of colophony, a natural resin used as an adhesive in this painting technique. Furthermore, the fresco cross section was studied using ToF‐SIMS imaging. ToF‐SIMS results agree with and are complementary to those obtained by other analytical techniques: scanning electron microscopy with X‐ray microanalysis and Fourier transform infrared spectroscopy. Copyright © 2016 John Wiley & Sons, Ltd.
Monitoring Early‐Stage Nanoparticle Assembly in Microdroplets by Optical Spectroscopy and SERS
Authors: Salmon Andrew R. , Esteban Ruben , Taylor Richard W. , Hugall James T. , Smith Clive A. , Whyte Graeme , Scherman Oren A. , Aizpurua Javier , Abell Chris , Baumberg Jeremy J.
Published: February 2016

Microfluidic microdroplets have increasingly found application in biomolecular sensing as well as nanomaterials growth. More recently the synthesis of plasmonic nanostructures in microdroplets has led to surface‐enhanced Raman spectroscopy (SERS)‐based sensing applications. However, the study of nanoassembly in microdroplets has previously been hindered by the lack of on‐chip characterization tools, particularly at early timescales. Enabled by a refractive index matching microdroplet formulation, dark‐field spectroscopy is exploited to directly track the formation of nanometer‐spaced gold nanoparticle assemblies in microdroplets. Measurements in flow provide millisecond time resolution through the assembly process, allowing identification of a regime where dimer formation dominates the dark‐field scattering and SERS. Furthurmore, it is shown that small numbers of nanoparticles can be isolated in microdroplets, paving the way for simple high‐yield assembly, isolation, and sorting of few nanoparticle structures.
In Situ Mitigation of Subsurface and Peripheral Focused Ion Beam Damage via Simultaneous Pulsed Laser Heating
Authors: Stanford Michael G. , Lewis Brett B. , Iberi Vighter , Fowlkes Jason D. , Tan Shida , Livengood Rick , Rack Philip D.
Published: February 2016

Focused helium and neon ion (He+/Ne+) beam processing has recently been used to push resolution limits of direct‐write nanoscale synthesis. The ubiquitous insertion of focused He+/Ne+ beams as the next‐generation nanofabrication tool‐of‐choice is currently limited by deleterious subsurface and peripheral damage induced by the energetic ions in the underlying substrate. The in situ mitigation of subsurface damage induced by He+/Ne+ ion exposures in silicon via a synchronized infrared pulsed laser‐assisted process is demonstrated. The pulsed laser assist provides highly localized in situ photothermal energy which reduces the implantation and defect concentration by greater than 90%. The laser‐assisted exposure process is also shown to reduce peripheral defects in He+ patterned graphene, which makes this process an attractive candidate for direct‐write patterning of 2D materials. These results offer a necessary solution for the applicability of high‐resolution direct‐write nanoscale material processing via focused ion beams.
Synthesis and characterization of cross‐linked starch/lignin film
Authors: Shi Ruixin , Li Bin
Published: February 2016

A cross‐linked film, based on corn starch/hydroxymethylated alkali lignin, was prepared. The effects of solution casting, pH, and reactant stoichiometries on water absorbability and mechanical properties of the starch/lignin film were studied. The microstructure, morphology, moisture absorbability, and thermal properties of the film were also evaluated. Results showed that the starch/lignin composite film, cast under optimized conditions, was homogeneous and soft. The tensile strength and elongation ratio of the composite film were higher than that of the corn starch film. At a temperature, higher than 320°C, the weight loss rate of the starch/lignin film was lower than that of the starch film and its char residue at 750°C was more than the corn starch film. This showed that the starch/lignin film had better thermal stability at higher temperatures. More importantly, the water absorption rate of starch/lignin film was 238 ± 3 %, which was 1.3 times than that of the corn starch film. The moisture content of the film was also higher than the corn starch sample. Hence, the prepared starch/lignin cross‐linked film can be used as a biodegradable, water absorbent material for packaging and in agricultural mulching.
A Role for RE-1-Silencing Transcription Factor in Embryonic Stem Cells Cardiac Lineage Specification
Authors: Aksoy Irene , Marcy Guillaume , Chen Jiaxuan , Divakar Ushashree , Kumar Vibhor , John-Sanchez Daniel , Rahmani Mehran , Buckley Noel J. , Stanton Lawrence W.
Published: February 2016

During development, lineage specification is controlled by several signaling pathways involving various transcription factors (TFs). Here, we studied the RE-1-silencing transcription factor (REST) and identified an important role of this TF in cardiac differentiation. Using mouse embryonic stem cells (ESC) to model development, we found that REST knockout cells lost the ability to differentiate into the cardiac lineage. Detailed analysis of specific lineage markers expression showed selective downregulation of endoderm markers in REST-null cells, thus contributing to a loss of cardiogenic signals. REST regulates cardiac differentiation of ESCs by negatively regulating the Wnt/β-catenin signaling pathway and positively regulating the cardiogenic TF Gata4. We propose here a new role for REST in cell fate specification besides its well-known repressive role of neuronal differentiation.
The Antiaging Gene Klotho Regulates Proliferation and Differentiation of Adipose-Derived Stem Cells
Authors: Fan Jun , Sun Zhongjie
Published: February 2016

Klotho was originally discovered as an aging-suppressor gene. The purpose of this study was to investigate whether secreted Klotho (SKL) affects the proliferation and differentiation of adipose-derived stem cells (ADSCs). RT-PCR and Western blot analysis showed that short-form Klotho was expressed in mouse ADSCs. The Klotho gene mutation KL(–/–) significantly decreased proliferation of ADSCs and expression of pluripotent transcription factors (Nanog, Sox-2, and Oct-4) in mice. The adipogenic differentiation of ADSCs was also decreased in KL(–/–) mice. Incubation with Klotho-deficient medium decreased ADSC proliferation, pluripotent transcription factor levels, and adipogenic differentiation, which is similar to what was found in KL(–/–) mice. These results indicate that Klotho deficiency suppresses ADSC proliferation and differentiation. Interestingly, treatment with recombinant SKL protein rescued the Klotho deficiency-induced impairment in ADSC proliferation and adipogenic differentiation. SKL also regulated ADSCs' differentiation to other cell lineages (osteoblasts, myofibroblasts), indicating that SKL maintains stemness of ADSCs. It is intriguing that overexpression of SKL significantly increased PPAR-γ expression and lipid formation in ADSCs following adipogenic induction, indicating enhanced adipogenic differentiation. Overexpression of SKL inhibited expression of TGFβ1 and its downstream signaling mediator Smad2/3. This study demonstrates, for the first time, that SKL is essential to the maintenance of normal proliferation and differentiation in ADSCs. Klotho regulates adipogenic differentiation in ADSCs, likely via inhibition of TGFβ1 and activation of PPAR-γ.
Serially Transplanted Nonpericytic CD146− Adipose Stromal/Stem Cells in Silk Bioscaffolds Regenerate Adipose Tissue In Vivo
Authors: Frazier Trivia P. , Bowles Annie , Lee Stephen , Abbott Rosalyn , Tucker Hugh A. , Kaplan David , Wang Mei , Strong Amy , Brown Quincy , He Jibao , Bunnell Bruce A. , Gimble Jeffrey M.
Published: February 2016

Progenitors derived from the stromal vascular fraction (SVF) of white adipose tissue (WAT) possess the ability to form clonal populations and differentiate along multiple lineage pathways. However, the literature continues to vacillate between defining adipocyte progenitors as “stromal” or “stem” cells. Recent studies have demonstrated that a nonpericytic subpopulation of adipose stromal cells, which possess the phenotype, CD45−/CD31−/CD146−/CD34+, are mesenchymal, and suggest this may be an endogenous progenitor subpopulation within adipose tissue. We hypothesized that an adipose progenitor could be sorted based on the expression of CD146, CD34, and/or CD29 and when implanted in vivo these cells can persist, proliferate, and regenerate a functional fat pad over serial transplants. SVF cells and culture expanded adipose stromal/stem cells (ASC) ubiquitously expressing the green fluorescent protein transgene (GFP-Tg) were fractionated by flow cytometry. Both freshly isolated SVF and culture expanded ASC were seeded in three-dimensional silk scaffolds, implanted subcutaneously in wild-type hosts, and serially transplanted. Six-week WAT constructs were removed and evaluated for the presence of GFP-Tg adipocytes and stem cells. Flow cytometry, quantitative polymerase chain reaction, and confocal microscopy demonstrated GFP-Tg cell persistence, proliferation, and expansion, respectively. Glycerol secretion and glucose uptake assays revealed GFP-Tg adipose was metabolically functional. Constructs seeded with GFP-Tg SVF cells or GFP-Tg ASC exhibited higher SVF yields from digested tissue, and higher construct weights, compared to nonseeded controls. Constructs derived from CD146− CD34+ -enriched GFP-Tg ASC populations exhibited higher hemoglobin saturation, and higher frequency of GFP-Tg cells than unsorted or CD29+ GFP-Tg ASC counterparts. These data demonstrated successful serial transplantation of nonpericytic adipose-derived progenitors that can reconstitute adipose tissue as a solid organ. These findings have the potential to provide new insights regarding the stem cell identity of adipose progenitor cells.
Concise Review: Mechanisms Behind Apoptotic Cell-Based Therapies Against Transplant Rejection and Graft versus Host Disease
Authors: Morelli Adrian E. , Larregina Adriana T.
Published: February 2016

The main limitations to the success of transplantation are the antigraft response developed by the recipient immune system, and the adverse side effects of chronic immunosuppression. Graft-versus-host disease (GVHD) triggered by donor-derived T lymphocytes against the recipient tissues is another serious obstacle in the field of hematopoietic stem cell transplantation. Several laboratories have tested the possibility of promoting antigen (Ag)-specific tolerance for therapy of graft rejection, GVHD, and autoimmune disorders, by developing methodologies that mimic the mechanisms by which the immune system maintains peripheral tolerance in the steady state. It has been long recognized that the silent clearance of cells undergoing apoptosis exerts potent immune-regulatory effects and provides apoptotic cell-derived Ags to those Ag-presenting cells (APCs) that internalize them, in particular macrophages and dendritic cells. Therefore, in situ-targeting of recipient APCs by systemic administration of leukocytes in early apoptosis and bearing donor Ags represents a relatively simple approach to control the antidonor response against allografts. Here, we review the mechanisms by which apoptotic cells are silently cleared by phagocytes, and how such phenomenon leads to down-regulation of the innate and adaptive immunity. We discuss the evolution of apoptotic cell-based therapies from murine models of organ/tissue transplantation and GVHD, to clinical trials. We make emphasis on potential limitations and areas of concern of apoptotic cell-based therapies, and on how other immune-suppressive therapies used in the clinics or tested experimentally likely also function through the silent clearance of apoptotic cells by the immune system.
Hyaluronan Is Crucial for Stem Cell Differentiation into Smooth Muscle Lineage
Authors: Simpson Russell M.L. , Hong Xuechong , Wong Mei Mei , Karamariti Eirini , Bhaloo Shirin Issa , Warren Derek , Kong Wei , Hu Yanhua , Xu Qingbo
Published: February 2016

Deciphering the extracellular signals that regulate SMC differentiation from stem cells is vital to further our understanding of the pathogenesis of vascular disease and for development of cell-based therapies and tissue engineering. Hyaluronan (HA) has emerged as an important component of the stem cell niche, however its role during stem cell differentiation is a complicated and inadequately defined process. This study aimed to investigate the role of HA in embryonic stem cell (ESC) differentiation toward a SMC lineage. ESCs were seeded on collagen-IV in differentiation medium to generate ESC-derived SMCs (esSMCs). Differentiation coincided with increased HA synthase (HAS) 2 expression, accumulation of extracellular HA and its assembly into pericellular matrices. Inhibition of HA synthesis by 4-methylumbelliferone (4MU), removal of the HA coat by hyaluronidase (HYAL) or HAS2 knockdown led to abrogation of SMC gene expression. HA activates ERK1/2 and suppresses EGFR signaling pathways via its principle receptor, CD44. EGFR inactivation coincided with increased binding to CD44, which was further augmented by addition of high molecular weight (HMW)-HA either exogenously or via HAS2 overexpression through adenoviral gene transfer. HMW-HA-stimulated esSMCs displayed a functional role in vascular tissue engineering ex vivo, vasculogenesis in a matrigel plug model and SMC accumulation in neointimal lesions of vein grafts in mice. These findings demonstrate that HAS2-induced HA synthesis and organization drives ESC-SMC differentiation. Thus, remodeling of the HA microenvironment is a critical step in directing stem cell differentiation toward a vascular lineage, highlighting HA as a potential target for treatment of vascular diseases.
Wnt/β-Catenin Signaling Determines the Vasculogenic Fate of Postnatal Mesenchymal Stem Cells
Authors: Zhang Zhaocheng , Nör Felipe , Oh Min , Cucco Carolina , Shi Songtao , Nör Jacques E.
Published: February 2016

Vasculogenesis is the process of de novo blood vessel formation observed primarily during embryonic development. Emerging evidence suggest that postnatal mesenchymal stem cells are capable of recapitulating vasculogenesis when these cells are engaged in tissue regeneration. However, the mechanisms underlining the vasculogenic differentiation of mesenchymal stem cells remain unclear. Here, we used stem cells from human permanent teeth (dental pulp stem cells [DPSC]) or deciduous teeth (stem cells from human exfoliated deciduous teeth [SHED]) as models of postnatal primary human mesenchymal stem cells to understand mechanisms regulating their vasculogenic fate. GFP-tagged mesenchymal stem cells seeded in human tooth slice/scaffolds and transplanted into immunodeficient mice differentiate into human blood vessels that anastomize with the mouse vasculature. In vitro, vascular endothelial growth factor (VEGF) induced the vasculogenic differentiation of DPSC and SHED via potent activation of Wnt/β-catenin signaling. Further, activation of Wnt signaling is sufficient to induce the vasculogenic differentiation of postnatal mesenchymal stem cells, while Wnt inhibition blocked this process. Notably, β-catenin-silenced DPSC no longer differentiate into endothelial cells in vitro, and showed impaired vasculogenesis in vivo. Collectively, these data demonstrate that VEGF signaling through the canonical Wnt/β-catenin pathway defines the vasculogenic fate of postnatal mesenchymal stem cells.
Protective Role of Adipose-Derived Stem Cells in Staphylococcus aureus-Induced Lung Injury is Mediated by RegIIIγ Secretion
Authors: Qian Jing , Hu Yue , Zhao Lifang , Xia Jingyan , Li Changwei , Shi Liyun , Xu Feng
Published: February 2016

Effective and specific therapeutic approaches are still needed for treating acute lung injury caused by severe pneumonia. Adipose-derived stem cells (ADSCs) are well-characterized adult stem cells that have antibacterial and anti-inflammatory effects. In this study, we evaluated the therapeutic effect of ADSCs on Staphylococcus aureus-induced acute lung injury in mice. Our results showed that intratracheal injection of ADSCs could attenuate the severity of lung inflammation, and reduce the bacterial load as well as mortality among infected mice. Our experiments also revealed that the secretion of regenerating islet-derived IIIγ (RegIIIγ) is responsible for the protective effect of ADSCs. Moreover, the expression of RegIIIγ requires TLR2, MyD88, and JAK2/STAT3 activation. In conclusion, ADSCs exhibit a direct antimicrobial activity that is mediated primarily by the TLR2-MyD88-JAK2/STAT3-dependent secretion of RegIIIγ.
Fascia Origin of Adipose Cells
Authors: Su Xueying , Lyu Ying , Wang Weiyi , Zhang Yanfei , Li Danhua , Wei Suning , Du Congkuo , Geng Bin , Sztalryd Carole , Xu Guoheng
Published: February 2016

Adipocytes might arise from vascular stromal cells, pericytes and endothelia within adipose tissue or from bone marrow cells resident in nonadipose tissue. Here, we identified adipose precursor cells resident in fascia, an uninterrupted sheet of connective tissue that extends throughout the body. The cells and fragments of superficial fascia from the rat hindlimb were highly capable of spontaneous and induced adipogenic differentiation but not myogenic and osteogenic differentiation. Fascial preadipocytes expressed multiple markers of adipogenic progenitors, similar to subcutaneous adipose-derived stromal cells (ASCs) but discriminative from visceral ASCs. Such preadipocytes resided in fascial vasculature and were physiologically active in vivo. In growing rats, adipocytes dynamically arose from the adventitia to form a thin adipose layer in the fascia. Later, some adipocytes appeared to overlay on top of other adipocytes, an early sign for the formation of three-dimensional adipose tissue in fascia. The primitive adipose lobules extended invariably along blood vessels toward the distal fascia areas. At the lobule front, nascent capillaries wrapped and passed ahead of mature adipocytes to form the distal neovasculature niche, which might replenish the pool of preadipocytes and supply nutrients and hormones necessary for continuous adipogenesis. Our findings suggest a novel model for the origin of adipocytes from the fascia, which explains both neogenesis and expansion of adipose tissue. Fascial preadipocytes generate adipose cells to form primitive adipose lobules in superficial fascia, a subcutaneous nonadipose tissue. With continuous adipogenesis, these primitive adipose lobules newly formed in superficial fascia may be the rudiment of subcutaneous adipose tissue.
Tumor Necrosis Factor α Regulates Endothelial Progenitor Cell Migration via CADM1 and NF-kB
Authors: Prisco Anthony R. , Hoffmann Brian R. , Kaczorowski Catherine C. , McDermott-Roe Chris , Stodola Timothy J. , Exner Eric C. , Greene Andrew S.
Published: February 2016

Shortly after the discovery of endothelial progenitor cells (EPCs) in 1997, many clinical trials were conducted using EPCs as a cellular based therapy with the goal of restoring damaged organ function by inducing growth of new blood vessels (angiogenesis). Results were disappointing, largely because the cellular and molecular mechanisms of EPC-induced angiogenesis were not clearly understood. Following injection, EPCs must migrate to the target tissue and engraft prior to induction of angiogenesis. In this study EPC migration was investigated in response to tumor necrosis factor α (TNFα), a pro-inflammatory cytokine, to test the hypothesis that organ damage observed in ischemic diseases induces an inflammatory signal that is important for EPC homing. In this study, EPC migration and incorporation were modeled in vitro using a coculture assay where TNFα treated EPCs were tracked while migrating toward vessel-like structures. It was found that TNFα treatment of EPCs increased migration and incorporation into vessel-like structures. Using a combination of genomic and proteomic approaches, NF-kB mediated upregulation of CADM1 was identified as a mechanism of TNFα induced migration. Inhibition of NF-kB or CADM1 significantly decreased migration of EPCs in vitro suggesting a role for TNFα signaling in EPC homing during tissue repair.
Junctional Adhesion Molecule-A Is Highly Expressed on Human Hematopoietic Repopulating Cells and Associates with the Key Hematopoietic Chemokine Receptor CXCR4
Authors: Chang Chao-Hui , Hale Sarah J , Cox Charlotte V. , Blair Allison , Kronsteiner Barbara , Grabowska Rita , Zhang Youyi , Cook David , Khoo Cheen P. , Schrader Jack B. , Kabuga Suranahi Buglass , Martin-Rendon Enca , Watt Suzanne M.
Published: February 2016

Hematopoietic stem/progenitor cells (HSPCs) reside in specialized bone marrow microenvironmental niches, with vascular elements (endothelial/mesenchymal stromal cells) and CXCR4-CXCL12 interactions playing particularly important roles for HSPC entry, retention, and maintenance. The functional effects of CXCL12 are dependent on its local concentration and rely on complex HSPC-niche interactions. Two Junctional Adhesion Molecule family proteins, Junctional Adhesion Molecule-B (JAM)-B and JAM-C, are reported to mediate HSPC-stromal cell interactions, which in turn regulate CXCL12 production by mesenchymal stromal cells (MSCs). Here, we demonstrate that another JAM family member, JAM-A, is most highly expressed on human hematopoietic stem cells with in vivo repopulating activity (p < .01 for JAM-Ahigh compared to JAM-AInt or Low cord blood CD34+ cells). JAM-A blockade, silencing, and overexpression show that JAM-A contributes significantly (p < .05) to the adhesion of human HSPCs to IL-1β activated human bone marrow sinusoidal endothelium. Further studies highlight a novel association of JAM-A with CXCR4, with these molecules moving to the leading edge of the cell upon presentation with CXCL12 (p < .05 compared to no CXCL12). Therefore, we hypothesize that JAM family members differentially regulate CXCR4 function and CXCL12 secretion in the bone marrow niche.
Treatment of canine meningoencephalomyelitis of unknown aetiology with mycophenolate mofetil and corticosteroids: 25 cases (2007–2012)
Authors: Woolcock Andrew D. , Wang Andrea , Haley Allison , Kent Marc , Creevy Kate E. , Platt Simon R.
Published: February 2016

The use of mycophenolate mofetil (MMF) for a variety of immune‐mediated diseases in veterinary medicine has been described. However, there is only a small number of cases documenting its use in dogs with meningoencephalomyelitis of unknown aetiology (MUE). We hypothesized that the use ofMMFand corticosteroids in dogs withMUEresults in comparable survival data to other published treatment protocols and is associated with limited adverse effects. A retrospective study of medical case records of dogs clinically diagnosed withMUErecorded signalment, neuroanatomic localization, magnetic resonance imaging findings, cerebrospinal fluid analysis results, medications administered, follow‐up neurologic examinations, survival and adverse events. Variables were compared between dogs which were treated withMMFwithin 30 days of diagnosis (immediate group) vs. dogs in whichMMFtherapy was started >30 days after diagnosis (delayed group). Twenty‐five cases ofMUEwere identified. The overall median survival time from diagnosis was 731 days (range 43–1672 days). After 1 month ofMMFtreatment, 92% of dogs showed improvement on a neurological examination. There was no significant effect of any recorded parameter on survival, including delayed vs. immediate initiation ofMMFtreatment. Dogs with delayed treatment had significantly lower clinical remission rates than dogs with immediate treatment at 6 months after startingMMF. Adverse events were identified in two cases (8%) and were characterized by mild gastrointestinal signs (vomiting and decreased appetite). Administration ofMMFappears safe in dogs withMUE. The use ofMMFresults in comparable survival times to alternate immunosuppressive protocols.
Computationally deciphering palladium‐catalyzed reaction mechanisms
Authors: Sperger Theresa , Fisher Henry C. , Schoenebeck Franziska
Published: February 2016

Computational studies receive increased attention in the mechanistic exploration of transition metal catalyzed reactions. Especially in Pd catalysis, numerous mechanistic insights could be gained by the use of computational tools to complement experimental studies in order to provide a more detailed mechanistic picture. This includes not only the exploration of novel mechanistic scenarios, but also the comparison of different plausible reaction pathways. The current intense use of calculations in mechanistic studies of Pd‐catalyzed reactions has encouraged constant advancements in the field. However, a number of challenges will be faced in the computational treatment of Pd reactivities, including tackling conformational space, charged molecules, varying ligation states and the description of complexes bearing multiple Pd centers. Their careful consideration may enrich the mechanistic picture of numerous Pd‐catalyzed reactions, but may also encourage further development of computational methodology. WIREs Comput Mol Sci 2016, 6:226–242. doi: 10.1002/wcms.1244

This article is categorized under:

Electronic Structure Theory > Density Functional Theory
Techniques for monitoring Brachyramphus murrelets: A comparison of radar, autonomous acoustic recording and audio‐visual surveys
Authors: Cragg Jenna L. , Burger Alan E. , Piatt John F.
Published: February 2016

Conditions in Alaska, USA, pose a challenge for monitoring populations of Brachyramphus murrelets using standard survey methods, because of strong winds, 2 sympatric species, short nights, and variable nesting habitat. We tested 3 methods for monitoring Brachyramphus murrelets breeding in the Kodiak Archipelago, Alaska, in 2010–2012. In addition to standard audio‐visual and radar methods, we tested—for the first time with murrelets in Alaska—the application of autonomous acoustic recorders for monitoring vocal activity. We completed 74 radar, 124 audio‐visual, and 134 autonomous acoustic surveys, focused on presunrise activity peaks; this yielded 26,375 murrelet detections. Marbled (B. marmoratus) and Kittlitz's murrelets (B. brevirostris) could not be distinguished using combinations of radar and acoustic recordings; therefore, at‐sea surveys will be required to determine localized species proportions. Of the 3 methods, radar sampled the largest area and detected silently flying murrelets, providing the most reliable data on local populations; however, radar identification of murrelets was unreliable in winds exceeding 18 km/hr. Audio‐visual surveys were useful for species identification and to document behaviors associated with local nesting, whereas autonomous acoustic recorders allowed season‐long monitoring of murrelet vocal activity. Within potential forest‐nesting habitat of marbled murrelets, all 3 methods gave similar measures of presunrise murrelet activity, but only radar reliably sampled murrelets commuting between nest and ocean. Because of their low cost and flexible programming, automated sound recorders offer an affordable way to sample vocal activity prior to more intensive or expensive radar and audio‐visual surveys. We recommend that population monitoring and habitat studies of Brachyramphus murrelets in Alaska include combinations of all 3 methods. Published 2016. This article is a U.S. Government work and is in the public domain in the USA.
Relation between Electric Spark Sensitivity and Impact Sensitivity of Nitroaromatic Energetic Compounds
Authors: Keshavarz Mohammad Hossein , Keshavarz Zahra
Published: February 2016

Impact and electric spark sensitivities of energetic compounds are two important sensitivity parameters, which are closely related to many accidents in working places. In contrast to electric spark sensitivity, impact sensitivity can be easily measured. A new simple method is introduced to correlate electric spark and impact sensitivities of nitroaromatic compounds. Two correcting functions are used to consider several molecular moieties for reliable prediction of electric spark sensitivity through the measured or estimated impact sensitivity of nitroaromatics. The model is optimized using a set of 28 CHNO polynitroaromatic explosives and then it is tested for some nitroaromatics containing the other atoms such as sulfur. The predicted electric sensitivities of the new method are also compared with the reported results of a new quantum mechanical approach. For 22 CHNO nitroaromatics, quantum mechanical calculations are within ±3.0 J of 18 measured values and more than ±3.0 J for remaining 4 experimental data. Meanwhile, the predicted results of the method are less than ±3.0 J for 28 CHNO nitroaromatics. The root‐mean‐square (rms) deviations of the new model and quantum mechanical are also 1.55 and 2.51 J, respectively.
Cervical cages placed bilaterally in the facet joints from a posterior approach significantly increase foraminal area
Authors: Siemionow Kris , Janusz Piotr , Glowka Pawel
Published: February 2016

Purpose

Foraminal stenosis is a common cause of cervical radiculopathy. Posterior cervical cages can indirectly increase foraminal area and decompress the nerve root. The aim of this study was to assess the influence of bilateral posterior cervical cages on the surface area and shape of the neural foramen.

Methods

Radiographic analysis was performed on 43 subjects enrolled in a prospective, multi-center study. CT scans were obtained at baseline and 6- and 12-months after cervical fusion using bilateral posterior cervical cages. The following measurements were performed on CT scan: foraminal area (A), theoretical area (TA), height (H), superior diagonal (DSI), inferior diagonal (DIS), and inferior diagonal without implant (DISI). Comparisons were performed using R-ANOVA with a significance of α < 0.05.

Results

Foraminal area, height, TA and DISI were significantly greater following placement of the implant. The mean (SD) A increased from 4.01 (1.09) mm2 before surgery to 4.24 (1.00) mm2 at 6 months, and 4.18 (1.05) mm2 at 12 months after surgery (p < 0.0001). Foraminal height (H) increased from mean (SD) 9.20 (1.08) mm at baseline to 9.65 (1.06) mm and 9.55 (1.14) mm at 6- and 12-months post-operatively, respectively (p < 0.0001). The mean DIS did not change significantly. There was a significant decrease in DSI: 6.18 (1.59) mm pre-operatively, 5.95 (1.47) mm and 5.73 (1.46) mm at 6- and 12-months (p < 0.0001).

Conclusions

Implantation of bilateral posterior cervical cages can increase foraminal area and may indirectly decompress the nerve roots. Correlation between increase in foraminal area and clinical outcomes needs further investigation.
Two randomized, double-blind, placebo-controlled, dose-escalation phase 1 studies evaluating BTH1677, a 1, 3–1,6 beta glucan pathogen associated molecular pattern, in healthy volunteer subjects
Authors: Halstenson C. E. , Shamp T. , Gargano M. A. , Walsh R. M. , Patchen M. L.
Published: February 2016

Background BTH1677 is a beta glucan pathogen associated molecular pattern (PAMP) currently being investigated as a novel cancer therapy. Here, the initial safety and pharmacokinetic (PK) results of BTH1677 in healthy subjects are reported. Subjects and Methods In the Phase 1a single-dosing study, subjects were randomized (3:1 per cohort) to a single intravenous (iv) infusion of BTH1677 at 0.5, 1, 2, 4, or 6 mg/kg or placebo, respectively. In the Phase 1b multi-dosing study, subjects were randomized (3:1 per cohort) to 7 daily iv infusions of BTH1677 at 1, 2, or 4 mg/kg or placebo, respectively. Safety and PK non-compartmental analyses were performed. Results Thirty-six subjects (N = 24 Phase 1a; N = 12 Phase 1b) were randomized to treatment. No deaths or serious adverse events occurred in either study. Mild or moderate adverse events (AEs) occurred in 67 % of BTH1677-treated subjects in both studies. Treatment-related AEs (occurring in ≥10 % of subjects) included dyspnea, flushing, headache, nausea, paraesthesia, and rash in Phase 1a and conjunctivitis and headache in Phase 1b. BTH1677 serum concentration was linear with dose. Clearance, serum elimination half-life (t1/2) and volume of distribution (Vss) were BTH1677 dose-independent. In Phase 1b, area under the curve, t1/2, and Vss values were larger at steady state on days 6–30 versus day 0. Conclusions BTH1677 was well tolerated after single doses up to 6 mg/kg and after 7 daily doses up to 4 mg/kg.
Trade Liberalization and Economic Growth in Guyana: An Empirical Assessment using DOLS and Error Correcting Methodologies
Authors: Modeste Nelson C.
Published: February 2016

This paper uses econometric techniques in the area of time series analysis to examine the relationship between economic performance and trade liberalization in Guyana. For this study, the base model underlying the analysis is a traditional per worker production function that has been augmented to include trade liberalization and other factors like human capital and exports. The results from this study suggest that when viewed from the long-run and short-run perspective trade liberalization has enhanced the economic performance of Guyana. Indeed, in this study both measures of trade liberalization - the average import tariff rate and the dummy variable representing the change in quota and import licensing measures, among other things - were statistically significant and correctly signed.
Is the Daily Deal Social Shopping?: An Empirical Analysis of Customer Panel Data
Authors: Song Minjae , Park Eunho , Yoo Byungjoon , Jeon Seongmin
Published: February 2016

Shortly after Groupon started its business in 2008, selling one deal a day with substantial price discounts, daily-deal sites became new online shopping places for many people. Starting with Groupon, most daily-deal sites required that voucher sales be higher than a predetermined number before deals become active. This feature, known as the “tipping point,” was a unique characteristic of the daily-deal business and is identified as one of the most prominent features of social shopping. Most daily-deal sites also required that a redemption period start after a deal was over and be fixed, usually 90 days, presumably to maximize the promotional effect of deals by encouraging rapid voucher redemption. The question remains, however, whether such features actually contributed to the success of the daily-deal industry. Using individual-level panel data from a major daily-deal site in Korea, we analyze whether consumers’ purchase and redemption behaviors were affected by these features and how consumers changed their behaviors as they continued to purchase and redeem vouchers over time. We find that the presence of the tipping point did not boost voucher sales and likely deterred new customers from buying deals right away. We also find that new customers tended to redeem their vouchers quickly, and this likely caused the small businesses that offered deals to become overwhelmed. It is not surprising, given our findings, that both Groupon and the Korean daily deal site abandoned the use of the tipping point and modified redemption rules.
Internet, consumer spending, and credit card balance: Evidence from US consumers
Authors: Basnet Hem C. , Donou‐Adonsou Ficawoyi
Published: February 2016

Utilizing the 2013 Survey of Consumer Finances data, the present study aims to examine the role of the Internet in carrying a credit card balance among US households. The central question of this study is whether or not households with Internet access have more favorable attitudes toward incurring more credit card balance. This study further investigates whether education, income, gender, age, race, etc., make any differences in carrying credit card debt when households have access to the Internet. Our results with the Tobit model show that having access to the Internet increases the probability of carrying a positive credit card balance by 4% to 5% compared to those who do not have access to the Internet. This result does not apply to older Americans. Our results further indicate that education decreases the probability of carrying a positive credit balance for households that have access to the Internet, while income and liquid assets may have little positive effect on that probability. The results suggest that Internet leads to more debt, but education could alleviate that debt.
StatNet Electroencephalogram: A Fast and Reliable Option to Diagnose Nonconvulsive Status Epilepticus in Emergency Setting
Authors: Ladino Lady Diana , Voll Alexandra , Dash Dianne , Sutherland Wes , Hernández-Ronquillo Lizbeth , Téllez-Zenteno Jose Francisco , Moien-Afshari Farzad
Published: February 2016

Background:The StatNet electrode set is a system that can be applied by a non-electroencephalogram (EEG) technologist after minimal training. The primary objectives of this study are to assess the quality and reliability of the StatNet recordings in comparison to the conventional EEG.Methods:Over 10 months, 19 patients with suspected nonconvulsive status epilepticus were included from university hospital emergency settings. Each patient received a StatNet EEG by a trained epilepsy fellow and a conventional EEG by registered technologists. We compared the studies in a blinded fashion, for the timeframe from EEG order to the setup time, start of acquisition, amount of artifact, and detection of abnormalities. The nonparametric Mann-Whitney two-sample t test was used for comparisons. The kappa score was used to assess reliability.Results:Mean age of patients was 61±16.3 (25-93) years. The inter-observer agreement for detection of abnormal findings was 0.83 for StatNet and 0.75 for conventional EEG. Nonconvulsive status epilepticus was detected in 10% (2/19) in both studies. The delay from the time of EEG requisition to acquisition was shorter in the StatNet (22.4±2.5 minutes) than the conventional EEG (217.7±44.6 minutes; p<0.0001). The setup time was also shorter in the StatNet (9.9±0.8 minutes) compared with the conventional EEG (17.8±0.8 minutes; p<0.0001). There was no difference in the percentage of artifact duration between the two studies (p=0.89).Conclusion:This study demonstrates that StatNet EEG is a practical and reliable tool in the emergency setting, which reduces the delay of testing compared with conventional EEG, without significant compromise of study quality.
A minimal subsystem of the Kari–Culik tilings
Authors: SIEFKEN JASON
Published: February 2016

The Kari–Culik tilings are formed from a set of 13 Wang tiles that tile the plane only aperiodically. They are the smallest known set of Wang tiles to do so and are not as well understood as other examples of aperiodic Wang tiles. We show that the $\mathbb{Z}^{2}$ action by translation on a certain subset of the Kari–Culik tilings, namely those whose rows can be interpreted as Sturmian sequences (rotation sequences), is minimal. We give a characterization of this space as a skew product as well as explicit bounds on the waiting time between occurrences of $m\times n$ configurations.
Schrödinger operators with dynamically defined potentials
Authors: DAMANIK DAVID
Published: February 2016

In this survey we discuss spectral and quantum dynamical properties of discrete one-dimensional Schrödinger operators whose potentials are obtained by real-valued sampling along the orbits of an ergodic invertible transformation. After an introductory part explaining basic spectral concepts and fundamental results, we present the general theory of such operators, and then provide an overview of known results for specific classes of potentials. Here we focus primarily on the cases of random and almost periodic potentials.