Almost strong edge-mode operators arising at the boundaries of certain interacting one-dimensional symmetry protected topological phases with Z2 symmetry have infinite temperature lifetimes that are ...nonperturbatively long in the integrability breaking terms, making them promising as bits for quantum information processing. We extract the lifetime of these edge-mode operators for small system sizes as well as in the thermodynamic limit. For the latter, a Lanczos scheme is employed to map the operator dynamics to a one-dimensional tight-binding model of a single particle in Krylov space. We find this model to be that of a spatially inhomogeneous Su-Schrieffer-Heeger model with a hopping amplitude that increases away from the boundary, and a dimerization that decreases away from the boundary. We associate this dimerized or staggered structure with the existence of the almost strong mode. Thus, the short time dynamics of the almost strong mode is that of the edge mode of the Su-Schrieffer-Heeger model, while the long time dynamics involves decay due to tunneling out of that mode, followed by chaotic operator spreading. We also show that competing scattering processes can lead to interference effects that can significantly enhance the lifetime.
The immobilization of redox proteins or enzymes onto conductive surfaces has application in the analysis of biological processes, the fabrication of biosensors, and in the development of green ...technologies and biochemical synthetic approaches. This review evaluates the methods through which redox proteins can be attached to electrode surfaces in a “wired” configuration, that is, one that facilitates direct electron transfer. The feasibility of simple electroactive adsorption onto a range of electrode surfaces is illustrated, with a highlight on the recent advances that have been achieved in biotechnological device construction using carbon materials and metal oxides. The covalent crosslinking strategies commonly used for the modification and biofunctionalization of electrode surfaces are also evaluated. Recent innovations in harnessing chemical biology methods for electrically wiring redox biology to surfaces are emphasized.
Electrifying biology: Analysis of the mechanism, kinetics and thermodynamics of redox proteins and enzymes is often dependant on the immobilization of such molecules onto electrode surfaces, as is the implementation of many bio‐hybrid systems for biosensing, synthesis, or green fuel applications. Herein we detail the methods available for such surface “wiring” and highlight the opportunities and challenges that arise in their application.
MaxEnt is a program for modelling species distributions from presence-only species records. This paper is written for ecologists and describes the MaxEnt model from a statistical perspective, making ...explicit links between the structure of the model, decisions required in producing a modelled distribution, and knowledge about the species and the data that might affect those decisions. To begin we discuss the characteristics of presence-only data, highlighting implications for modelling distributions. We particularly focus on the problems of sample bias and lack of information on species prevalence. The keystone of the paper is a new statistical explanation of MaxEnt which shows that the model minimizes the relative entropy between two probability densities (one estimated from the presence data and one, from the landscape) defined in covariate space. For many users, this viewpoint is likely to be a more accessible way to understand the model than previous ones that rely on machine learning concepts. We then step through a detailed explanation of MaxEnt describing key components (e.g. covariates and features, and definition of the landscape extent), the mechanics of model fitting (e.g. feature selection, constraints and regularization) and outputs. Using case studies for a Banksia species native to south-west Australia and a riverine fish, we fit models and interpret them, exploring why certain choices affect the result and what this means. The fish example illustrates use of the model with vector data for linear river segments rather than raster (gridded) data. Appropriate treatments for survey bias, unprojected data, locally restricted species, and predicting to environments outside the range of the training data are demonstrated, and new capabilities discussed. Online appendices include additional details of the model and the mathematical links between previous explanations and this one, example code and data, and further information on the case studies.
Culture and decision making Yates, J. Frank; de Oliveira, Stephanie
Organizational behavior and human decision processes,
09/2016, Letnik:
136
Journal Article
Recenzirano
Odprti dostop
•We review the literature on culture and decision making.•We comprehensively analyze ten decision making phases.•Possible causes of cultural differences are reviewed and critiqued.•Big-picture ...questions for future research are discussed.
The study of culture and decision making addresses variations in how and why people from different cultures sometimes tend to decide differently. This review is organized around what is intended to be a comprehensive analysis of the distinct fundamental questions that people must answer in the process of making virtually all real-life decisions. Our emphasis was on recent developments as well as identifying important yet neglected topics (e.g., how decision episodes get started—or not, and why some decisions are never implemented). Early as well as current efforts have focused mainly on East Asian and North American Caucasian cultures, with little treatment of other populations. In such studies, individualism and collectivism have been the dominant explanatory factors although related but distinct concepts such as “tightness” and “looseness” have been welcome additions to recent discussions. Throughout, the review emphasizes practical concerns, such as the challenges of intercultural learning and collaboration.
Local plastic strain evolution in a high strength dual-phase steel Ghadbeigi, H.; Pinna, C.; Celotto, S. ...
Materials science & engineering. A, Structural materials : properties, microstructure and processing,
07/2010, Letnik:
527, Številka:
18-19
Journal Article
Recenzirano
Odprti dostop
The evolution of local plastic deformation in a dual-phase (DP) steel has been studied using Digital Image Correlation (DIC) and in-situ tensile testing inside a scanning electron microscope. Tests ...were performed using specially designed samples to study the initiation and evolution of damage in DP1000 steel by measuring the strains at the scale of the microstructure. Micrographs have been analysed using DIC at different stages throughout a tensile test to measure local strain distributions within the ferrite–martensite microstructure. The results show progressive localisation of deformation into bands orientated at 45° with respect to the loading direction. Strain magnitudes are higher in the ferrite phase with local values reaching up to 120%. Several mechanisms for damage initiation are identified and related to the local strains in this steel. The procedure used and the results obtained in this work may help the development of models aimed at predicting the properties of new generation automotive steels.
Consistent with recent reports indicating that neurons differentiated in vitro from human-induced pluripotent stem cells (hiPSCs) are immature relative to those in the human brain, gene expression ...comparisons of our hiPSC-derived neurons to the Allen BrainSpan Atlas indicate that they most resemble fetal brain tissue. This finding suggests that, rather than modeling the late features of schizophrenia (SZ), hiPSC-based models may be better suited for the study of disease predisposition. We now report that a significant fraction of the gene signature of SZ hiPSC-derived neurons is conserved in SZ hiPSC neural progenitor cells (NPCs). We used two independent discovery-based approaches-microarray gene expression and stable isotope labeling by amino acids in cell culture (SILAC) quantitative proteomic mass spectrometry analyses-to identify cellular phenotypes in SZ hiPSC NPCs from four SZ patients. From our findings that SZ hiPSC NPCs show abnormal gene expression and protein levels related to cytoskeletal remodeling and oxidative stress, we predicted, and subsequently observed, aberrant migration and increased oxidative stress in SZ hiPSC NPCs. These reproducible NPC phenotypes were identified through scalable assays that can be applied to expanded cohorts of SZ patients, making them a potentially valuable tool with which to study the developmental mechanisms contributing to SZ.
ProLuCID, a new algorithm for peptide identification using tandem mass spectrometry and protein sequence databases has been developed. This algorithm uses a three tier scoring scheme. First, a ...binomial probability is used as a preliminary scoring scheme to select candidate peptides. The binomial probability scores generated by ProLuCID minimize molecular weight bias and are independent of database size. A modified cross-correlation score is calculated for each candidate peptide identified by the binomial probability. This cross-correlation scoring function models the isotopic distributions of fragment ions of candidate peptides which ultimately results in higher sensitivity and specificity than that obtained with the SEQUEST XCorr. Finally, ProLuCID uses the distribution of XCorr values for all of the selected candidate peptides to compute a Z score for the peptide hit with the highest XCorr. The ProLuCID Z score combines the discriminative power of XCorr and DeltaCN, the standard parameters for assessing the quality of the peptide identification using SEQUEST, and displays significant improvement in specificity over ProLuCID XCorr alone. ProLuCID is also able to take advantage of high resolution MS/MS spectra leading to further improvements in specificity when compared to low resolution tandem MS data. A comparison of filtered data searched with SEQUEST and ProLuCID using the same false discovery rate as estimated by a target-decoy database strategy, shows that ProLuCID was able to identify as many as 25% more proteins than SEQUEST. ProLuCID is implemented in Java and can be easily installed on a single computer or a computer cluster.
This article is part of a Special Issue entitled: Computational Proteomics.
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This guideline supersedes a prior one from 2007 on a similar topic. The work group evaluated the available literature concerning various aspects of patient screening, risk factor assessment, and ...prophylactic treatment against venous thromboembolic disease (VTED), as well as the use of postoperative mobilization, neuraxial agents, and vena cava filters. The group recommended further assessment of patients who have had a previous venous thromboembolism but not for other potential risk factors. Patients should be assessed for known bleeding disorders, such as hemophilia, and for the presence of active liver disease. Patients who are not at elevated risk of VTED or for bleeding should receive pharmacologic prophylaxis and mechanical compressive devices for the prevention of VTED. The group did not recommend specific pharmacologic agents and/or mechanical devices. The work group recommends, by consensus opinion, early mobilization for patients following elective hip and knee arthroplasty. The use of neuraxial anesthesia can help limit blood loss but was not found to affect the occurrence of VTED. No clear evidence was established regarding whether inferior vena cava filters can prevent pulmonary embolism in patients who have a contraindication to chemoprophylaxis and/or known VTED.
In this manuscript, the inorganic perovskite CsPbI2Br is investigated as a photovoltaic material that offers higher stability than the organic–inorganic hybrid perovskite materials. It is ...demonstrated that CsPbI2Br does not irreversibly degrade to its component salts as in the case of methylammonium lead iodide but instead is induced (by water vapor) to transform from its metastable brown cubic (1.92 eV band gap) phase to a yellow phase having a higher band gap (2.85 eV). This is easily reversed by heating to 350 °C in a dry environment. Similarly, exposure of unencapsulated photovoltaic devices to water vapor causes current (J SC) loss as the absorber transforms to its more transparent (yellow) form, but this is also reversible by moderate heating, with over 100% recovery of the original device performance. NMR and thermal analysis show that the high band gap yellow phase does not contain detectable levels of water, implying that water induces the transformation but is not incorporated as a major component. Performances of devices with best efficiencies of 9.08% (V OC = 1.05 V, J SC = 12.7 mA cm–2 and FF = 68.4%) using a device structure comprising glass/ITO/c-TiO2/CsPbI2Br/Spiro-OMeTAD/Au are presented, and further results demonstrating the dependence of the performance on the preparation temperature of the solution processed CsPbI2Br films are shown. We conclude that encapsulation of CsPbI2Br to exclude water vapor should be sufficient to stabilize the cubic brown phase, making the material of interest for use in practical PV devices.
Ultraviolet light-induced electron−hole pair excitations in anatase TiO2 powders were studied by a combination of electron paramagnetic resonance and infrared spectroscopy measurements. During ...continuous UV irradiation in the mW.cm-2 range, photogenerated electrons are either trapped at localized sites, giving paramagnetic Ti3+ centers, or remain in the conduction band as EPR silent species which may be observed by their IR absorption. Using low temperatures (90 K) to reduce the rate of the electron−hole recombination processes, trapped electrons and conduction band electrons exhibit lifetimes of hours. The EPR-detected holes produced by photoexcitation are O- species, produced from lattice O2- ions. It is found that under high vacuum conditions, the major fraction of photoexcited electrons remains in the conduction band. At 298 K, all stable hole and electron states are lost from TiO2. Defect sites produced by oxygen removal during annealing of anatase TiO2 are found to produce a Ti3+ EPR spectrum identical to that of trapped electrons, which originate from photoexcitation of oxidized TiO2. Efficient electron scavenging by adsorbed O2 at 140 K is found to produce two long-lived O2 - surface species associated with different cation surface sites. Reduced TiO2, produced by annealing in vacuum, has been shown to be less efficient in hole trapping than oxidized TiO2.
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