Quantum Point Contacts and Coherent Electron Focusing

I. Introduction II. Electrons at the Fermi level III. Conductance quantization of a quantum point contact IV. Optical analogue of the conductance quantization V. Classical electron focusing VI. Electron focusing as a transmission problem VII. Coherent electron focusing (Experiment, Skipping orbits and magnetic edge states, Mode-interference and coherent electron focusing) VIII. Other mode-interference phenomenaComment: #3 of a series of 4 legacy reviews on QPC'

TRY plant trait database - enhanced coverage and open access

Plant traits-the morphological, anatomical, physiological, biochemical and phenological characteristics of plants-determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait-based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits-almost complete coverage for 'plant growth form'. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait-environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives

TRY plant trait database - enhanced coverage and open access

Plant traits—the morphological, anatomical, physiological, biochemical and phenological characteristics of plants—determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait‐based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits—almost complete coverage for ‘plant growth form’. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait–environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives

Environmental Geotechnics: Challenges and Opportunities in the Post COVID-19 World

The outbreak of the COVID-19 pandemic not only created a health crisis across the world but is expected to negatively impact the global economy and societies at a scale that maybe larger than the 2008 financial crisis. Simultaneously, it has inevitably exerted many negative consequences on the geoenvironment upon which human beings depend. The current article articulates the role of environmental geotechnics to elucidate and mitigate the effects of the current pandemic. It is the belief of all authors that the COVID-19 pandemic presents significant challenges, but also opportunities for the development of our field. Our discipline should make full use of our professional skills and expertise to look for development opportunities from this crisis, to highlight our discipline’s irreplaceable position in the global fight against pandemics, and to contribute to the health and prosperity of our communities, so as to better serve humankind. In order to reach this goal, while taking into account the specificity of the SARS-CoV-2 and the uncertainty of its environmental effects, it is believed that more emphasis should be placed on the following research directions: pathogen-soil interactions, isolation and remediation technologies for pathogen-contaminated sites, new materials for pathogen-contaminated soil, recycling and safe disposal of medical wastes, quantification of uncertainty in geoenvironmental and epidemiological problems, emerging technologies and adaptation strategies in civil, geotechnical, and geoenvironmental infrastructure, pandemic-induced environmental risk management, and model pathogen transport and fate in geoenvironment, among others. Moreover, COVID-19 has made it clear to the environmental geotechnics community the importance of urgent international cooperation and of multidisciplinary research actions that must extend to a broad range of scientific fields, including medical and public health disciplines, in order to meet the complexities posed by the COVID-19 pandemic

Communication through a diffusive medium: coherence and capacity

Coherent wave propagation in disordered media gives rise to many fascinating phenomena as diverse as universal conductance fluctuations in mesoscopic metals and speckle patterns in light scattering. Here, the theory of electromagnetic wave propagation in diffusive media is combined with information theory to show how interference affects the information transmission rate between antenna arrays. Nontrivial dependencies of the information capacity on the nature of the antenna arrays are found, such as the dimensionality of the arrays and their direction with respect to the local scattering medium. This approach provides a physical picture for understanding the importance of scattering in the transfer of information through wireless communications

Translatable Research Group-Based Undergraduate Research Program for Lower-Division Students

Participating in undergraduate research yields positive outcomes for undergraduate students, and universities are seeking ways to engage more students in undergraduate research earlier in their academic careers. Typically, undergraduate students perform research either as part of an apprenticeship where a student receives individual mentorship in a research lab setting from an experienced researcher in the field of interest or in a course-based undergraduate research experience where students work in a classroom or teaching laboratory to investigate open-ended research questions. In this work, we implement a model of undergraduate research that combines aspects of those two methods to provide benefits to undergraduate students and research groups. A cohort of 20 first-year undergraduate students at the University of California-Berkeley were recruited to work on a project investigating data previously collected by the Alivisatos research group. Over a semester, these students learned about nanomaterials and the research process, pursued curiosity-driven research in teams, and presented their results at a formal poster session. Students from this program showed quantifiable gains in their self-identification as researchers and scientists. This program was developed to be a model for other research groups, departments, and universities to combine the benefits of traditional apprenticeship research and course-based undergraduate research to provide a research experience for large numbers of undergraduate students early in their college education

Measuring integrated understanding of undergraduate chemistry research experiences: assessing oral and written research artifacts

Understanding the impact of undergraduate research experiences (UREs) and course-based undergraduate research experiences (CUREs) is crucial as universities debate the value of allocating scarce resources to these activities. We report on the Berkeley Undergraduate Research Evaluation Tools (BURET), designed to assess the learning outcomes of UREs and CUREs in chemistry and other sciences. To validate the tools, we administered BURET to 70 undergraduate students in the College of Chemistry and 19 students from other STEM fields, comparing the performance of students who had less than one year of undergraduate research to those with more than one year of research experience. Students wrote reflections and responded to interviews during poster presentations of their research project. BURET asks students to communicate the significance of their project, analyze their experimental design, interpret their data, and propose future research. Scoring rubrics reward students for integrating disciplinary evidence into their narratives. We found that the instruments yielded reliable scores, and the results clarified the impacts of undergraduate research, specifically characterizing the strengths and weaknesses of undergraduate researchers in chemistry at our institution. Students with at least a year of research experience were able to use disciplinary evidence more effectively than those with less than one year of experience. First-year students excelled at explaining the societal relevance of their work, but they incorporated only minimal discussion of prior research into their reflections and presentations. Students at all levels struggled to critique their own experimental design. These results have important implications for undergraduate learning, suggesting areas for faculty members, graduate student research mentors, and CURE or URE programs to improve undergraduate research experiences

Investigating the Binding Mode of an Inhibitor of the MBNL1·RNA Complex in Myotonic Dystrophy Type 1 (DM1) Leads to the Unexpected Discovery of a DNA-Selective Binder

New compounds containing a novel zinc binding group (salicylaldoxime system) were identified as effective inhibitors of carbonic anhydrases (CAs). This structural motif seems to bind the catalytic zinc ion of CAs, revealing itself as a new valid alternative to the sulfonamide group. Computational procedures were used to investigate the binding mode of this class of compounds, within the active site of CAII. This study suggests that the salicylaldoxime moiety binds the zinc ion through the oxime oxygen atom that also forms an H-bond with T199. The results herein obtained will allow the development of new CA-inhibitors bearing the salicylaldoxime moiety