Comparison of Monolithic Optical Frequency Comb Generators Based on Passively Mode-Locked Lasers for Continuous Wave mm-Wave and Sub-THz Generation

In this paper, two different Passive Mode-Locked Laser Diodes (PMLLD) structures, a Fabry-Perot cavity and a ring cavity laser are characterized and evaluated as monolithic Optical Frequency Comb Generators (OFCG) for CW sub-THz generation. An extensive characterization of the devices under study is carried out based on an automated measurement system that systematically evaluates the dynamic characteristics of the devices, focusing on the figures of merit that define the optimum performance of a pulsed laser source when considered as an OFCG. Sub-THz signals generated with both devices at 60 GHz and 90 GHz are presented and analyzed in terms of electrical linewidth to compare such components for mm-Wave and sub-THz photonic generation. This work offers a systematic comparison of PMLLD devices for OFCG operation and provides reference information of the performance of two different device topologies that can be used for the implementation of photonic integrated sub-THz CW generation.We acknowledge COBRA Research Institute, Eindhoven University of Technology, the Netherlands for the fabrication of the ring lasers within the joint European platform for InP-based components and circuits, JePPIX.Publicad

Effects of in-plane magnetic fields on the electronic cyclotron effective mass and Landé factor in GaAs-(Ga,Al)As quantum wells

The dependence of the electron Landé g-factor on carrier confinement in quantum wells recently gained both experimental and theoretical interest. The g factor of electrons in GaAs-(Ga,Al)As quantum wells is of special interest, as it changes its sign at a certain value of the well width. In the present work, the effects of an in-plane magnetic field on the cyclotron effective mass and on the Landé g^-factor in single GaAs-(Ga,Al)As quantum wells are studied. Theoretical calculations are performed in the framework of the effective-mass and non-parabolic-band approximations. The Ogg-McCombe Hamiltonian is used for the conduction-band electrons in the semiconductor heterostructure, and the Landé g^-factor theoretically evaluated is found in good agrement with available experimental measurements.858861Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Blocking two-component signalling enhances Candida albicans virulence and reveals adaptive mechanisms that counteract sustained SAPK activation

This work was funded by the UK Biotechnology and Biological Research Council [www.bbsrc.ac.uk] JQ (BB/K016393/1); AJPB (BB/K017365/1). The work was also supported by the Wellcome Trust [www.wellcome.ac.uk], JQ (086048, 097377); AJPB (097377)); LPE (097377). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Peer reviewedPublisher PD

Efficacy of Stochastic Vestibular Stimulation to Improve Locomotor Performance in a Discordant Sensory Environment

Astronauts exposed to microgravity face sensorimotor challenges incurred when readapting to a gravitational environment. Sensorimotor Adaptability (SA) training has been proposed as a countermeasure to improve locomotor performance during re-adaptation, and it is suggested that the benefits of SA training may be further enhanced by improving detection of weak sensory signals via mechanisms such as stochastic resonance when a non-zero level of stochastic white noise based electrical stimulation is applied to the vestibular system (stochastic vestibular stimulation, SVS). The purpose of this study was to test the efficacy of using SVS to improve short-term adaptation in a sensory discordant environment during performance of a locomotor task

Correlated electron-hole transitions in bulk GaAs and GaAs-(Ga,Al)As quantum wells: effects of applied electric and in-plane magnetic fields

The effects of crossed electric and magnetic fields on the electronic and exciton properties in semiconductor heterostructures have been investigated within the effective-mass and parabolic band approximations for both bulk GaAs and GaAs-Ga1-xAl xAs quantum wells. The combined effects on the heterostructure properties of the applied crossed electric/magnetic fields together with the direct coupling between the exciton center of mass and internal exciton motions may be dealt with via a simple parameter representing the distance between the electron and hole magnetic parabolas. Calculations lead to the expected behavior for the exciton dispersion in a wide range of the crossed electric/magnetic fields, and present theoretical results are found in good agreement with available experimental measurements.10381041Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Evaluation of English Self-Learning Modules in the Implementation of Modular Distance Learning

In response to the call that education must continue in the midst of the COVID- 19 pandemic, Self-Learning Modules (SLM) became the Department of Education’s primary learning resource in the implementation of a wide-scale Modular Distance Learning. With the educational landscape being confronted with numerous concerns that questions the quality of its SLMs,   their evaluation plays an extremely crucial role in pursuit of quality education.  The study evaluated English Self-Learning Modules used by Grade 7 students in the First Quarter and propose an enhanced learning material that will be helpful in their modular distance learning experience. The study sought to answer the following questions: (1) What are the strengths and weaknesses of the Self-Learning Modules in terms of: Intellectual Property Rights Compliance, Learning Competencies, Instructional Design and Organization, Instructional Quality, Assessment, and, Readability?; (2) What are the Alternative Interventions suggested to strengthen the identified weaknesses in the Self-Learning Modules?; and, (3) What Enhanced Self-Learning Modules may be proposed based on the strengths and weaknesses of the evaluated materials?     Using a purposive sampling, the Key Informants of the study included a total of eight (8) English teachers coming from three different secondary school locales from Legazpi City Division namely: Legazpi City National High School, Gogon High School and Cabangan High School. The study used a mixed method using a Descriptive –Evaluative Design where Key Informants answered a Survey Questionnaire and underwent Key Informants Interview to record the strengths and weaknesses of the Self-Learning Modules. Thematic analysis and percentage were used in the study to identify salient themes from qualitative and quantitative responses of the participants, respectively.   Relevant findings revealed that the strengths of Self-Learning Modules are (1) accuracy in citations, (2) copyright compliance (3) proper acknowledgement of the references, (4) accuracy in content, (5) appropriate presentation of objectives, (6) logical organization of content, (7) integration of valuable traits, (8) development of 21st century skills, (9) alignment of assessments to lesson objectives and (10) appropriateness of content and vocabulary to the learners’ level.    On the other hand,  Self-Learning Modules displayed weaknesses on the following areas: (1) rotten links, (2) missing bibliographies and references, (3) unpacking of broad competencies (4) outdated content and information, (5) grammatical errors, (6) development of lessons that allow for review, (7) providing answer keys, (8) unclear presentation of instruction and (9) seamless transitions of lessons.   To strengthen the identified weaknesses, the researchers developed a Guide Book that discusses the alternative interventions suggested by the researchers based on their insights together with the recommendations of educators.  The Guide Book aims to empower every module user to become involved in creating an improved Modular Learning experience. Moreover, the Enhanced Self-Learning Modules offshoot retained the revealed strengths and carefully applied the alternative interventions to strengthen the weaknesses. Finally, specific recommendations were suggested aimed towards the improvement of learning experiences

Integrative Model of Oxidative Stress Adaptation in the Fungal Pathogen Candida albicans

Acknowledgments We are grateful to the Ian Fraser Cytometry Centre and our Mass Spetrometry and qPCR Facilities for help with the flow cytometry, glutathione and qRT-PCR assays, respectively. We also thank our many colleagues in the CRISP Consortium and in the medical mycology and systems biology communities for insightful discussions. Funding: This work was supported by the CRISP project (Combinatorial Responses In Stress Pathways), which was funded by the UK Biotechnology and Biological Research Council (www.bbsrc.ac.uk): AJPB, KH, CG, ADM, NARG, MT, MCR. (Research Grants; BB/F00513X/1, BB/F005210/1-2). AJPB and JQ received additional support from the BBSRC (Research Grants; BB/K016393/1; BB/K017365/1). NARG and AJPB were also supported by the Wellcome Trust (www.wellcome.ac.uk), (Grants: 080088; 097377). AJPB was also supported by the European Research Council (http://erc.europa.eu/), (STRIFE Advanced Grant; ERC-2009-AdG-249793). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Peer reviewedPublisher PD

Moving from Specifications to Contracts in Component-Based Design

Abstract. Program properties that are automatically inferred by static analysis tools are generally not considered to be completely trustworthy, unless the tool implementation or the results are formally verified. Here we focus on the formal verification of resource guarantees inferred by automatic cost analysis. Resource guarantees ensure that programs run within the indicated amount of resources which may refer to memory consumption, to number of instructions executed, etc. In previous work we studied formal verification of inferred resource guarantees that depend only on integer data. In realistic programs, however, resource consumption is often bounded by the size of heap-allocated data structures. Bounding their size requires to perform a number of structural heap analyses. The contributions of this paper are (i) to identify what exactly needs to be verified to guarantee sound analysis of heap manipulating programs, (ii) to provide a suitable extension of the program logic used for verification to handle structural heap properties in the context of resource guarantees, and (iii) to improve the underlying theorem prover so that proof obligations can be automatically discharged.