The Impact of Dormant Defects on Defect Prediction: A Study of 19 Apache Projects

Defect prediction models can be beneficial to prioritize testing, analysis, or code review activities, and has been the subject of a substantial effort in academia, and some applications in industrial contexts. A necessary precondition when creating a defect prediction model is the availability of defect data from the history of projects. If this data is noisy, the resulting defect prediction model could result to be unreliable. One of the causes of noise for defect datasets is the presence of “dormant defects,” i.e., of defects discovered several releases after their introduction. This can cause a class to be labeled as defect-free while it is not, and is, therefore “snoring.” In this article, we investigate the impact of snoring on classifiers' accuracy and the effectiveness of a possible countermeasure, i.e., dropping too recent data from a training set. We analyze the accuracy of 15 machine learning defect prediction classifiers, on data from more than 4,000 defects and 600 releases of 19 open source projects from the Apache ecosystem. Our results show that on average across projects (i) the presence of dormant defects decreases the recall of defect prediction classifiers, and (ii) removing from the training set the classes that in the last release are labeled as not defective significantly improves the accuracy of the classifiers. In summary, this article provides insights on how to create defects datasets by mitigating the negative effect of dormant defects on defect prediction.

Design framework for polarization-insensitive multifunctional achromatic metalenses

Controlling the wavefront of light, especially on a subwavelength scale, is pivotal in modern optics. Metasurfaces present a unique platform for realizing flat lenses, called metalenses, with thicknesses on the order of the wavelength. Despite substantial effort, however, suppressing the chromatic aberrations over large operational bandwidths of metalenses still remains a challenge. Here, we develop a systematic design method enabling a simultaneous, polarization-insensitive control of the phase and the group delay of a light beam based on libraries of transmission-mode dielectric meta-elements. Mid-infrared achromatic metalenses are designed and theoretically analyzed to have diffraction-limited focal spots with vanishing chromatic aberrations in the operating wavelength range of 6–8.5 μm, while maintaining high focusing efficiencies of 41% on average. The proposed methodology, which can be used as a general design rule for all spectra, also provides a versatile design scheme for ultrashort pulse focusing and achromatic vortex-beam generation (orbital angular momentum), representing a major advance toward practical implementations of functional metalenses.

The latest covid-19 impact on the neurosurgery resident admission and training in Morocco

The Kingdom of Morocco is also affected by the COVID-19 in all filed. The coronavirus shutdown has been a great challenge for health policymakers, the citizens, and those traveling down for various reasons. Among them, there are undergraduate students, physicians seeking postgraduate education…etc. Some were lucky enough to start their courses online, pending the time to come to Morocco for continuing their studies. But unfortunately, this was not the case for the potential neurosurgical residents that were already accepted, and some were even holding scholarships but were unable to join their training centers. Meanwhile, a substantial effort has been made to feel the tremendous lack of neurosurgeons in Sub-Saharan Africa by quality massive education and training of neurosurgeons from those countries. Thus, these consequences of the COVID-19 shutdown are a dropping stone in a quiet lack, delaying the important project of the WFNS and others to fill up this gap. At the same time, it is worth thinking about the innovative model of neurosurgical education and training for the new generation of Sub-Saharan African neurosurgeons.

Institutional Pressures, Sustainable Development Goals and Covid-19: How Are Organisations Engaging?

This article aimed at answering the following research question: How do institutional pressures influence the engagement of organisations with the Sustainable Development Goals (SDGs) in the context of the COVID-19 pandemic? To address it, we applied a survey with Brazilian organisations in late 2020. From group analysis and the comparison of means (test‑t), we conclude that, in the pandemic scenario, organisations from various sectors and industries are affected mainly by coercive pressures but also by normative and, to a lesser extent, mimetic pressures. Furthermore, this study has shown that while opportunities are arising from normative and mimetic institutional pressures, it is in the coercive pressures that the guidance lies for the re-establishment of economic, social, and environmental development and prosperity in a post-pandemic scenario. Thus, despite some optimistic results, achieving the purpose outlined by the 2030 Agenda seems to be distant or at least needs an even more substantial effort if its responsibility rests solely with legislative and governmental forces.

Application of Artificial Intelligence in Early Gastric Cancer Diagnosis

<b><i>Background:</i></b> With the development of new technologies such as magnifying endoscopy with narrow band imaging, endoscopists achieved better accuracy for diagnosis of gastric cancer (GC) in various aspects. However, to master such skill takes substantial effort and could be difficult for inexperienced doctors. Therefore, a novel diagnostic method based on artificial intelligence (AI) was developed and its effectiveness was confirmed in many studies. AI system using convolutional neural network has showed marvelous results in the ongoing trials of computer-aided detection of colorectal polyps. <b><i>Summary:</i></b> With AI’s efficient computational power and learning capacities, endoscopists could improve their diagnostic accuracy and avoid the overlooking or over-diagnosis of gastric neoplasm. Several systems have been reported to achieved decent accuracy. Thus, AI-assisted endoscopy showed great potential on more accurate and sensitive ways for early detection, differentiation, and invasion depth prediction of gastric lesions. However, the feasibility, effectiveness, and safety in daily practice remain to be tested. <b><i>Key messages:</i></b> This review summarizes the current status of different AI applications in early GC diagnosis. More randomized controlled trails will be needed before AI could be widely put into clinical practice.

Preparation of Crystalline LaFeO3 Nanoparticles at Low Calcination Temperature: Precursor and Synthesis Parameter Effects

Substantial effort has been devoted to fabricating nanocrystalline lanthanum ferrite (LaFeO3), and calcination is the crucial process of crystallization in both high-temperature strategies and wet chemical methods. Lowering the calcination temperature gives the ability to resist the growth and agglomeration of nanoparticles, therefore contributing to preserve their unique nanostructures and properties. In this work, we prepared crystalline LaFeO3 nanoparticles with a calcination process at 500 °C, lower than the calcination temperature required in most wet chemistry methods. Correspondingly, the experimental conditions, including stoichiometric ratios, pH values, precipitants, complexant regent, and the calcination temperatures, were investigated. We found that the crystalline LaFeO3 was formed with crystalline NaFeO2 after calcination at 500 °C. Furthermore, the structure of FeO6 octahedra that formed in coprecipitation was associated with the process of crystallization, which was predominantly determined by calcination temperature. Moreover, an illusion of pure-phase LaFeO3 was observed when investigated by X-ray diffraction spectroscopy, which involves amorphous sodium ferrite or potassium ferrite, respectively. These findings can help prepare nanostructured perovskite oxides at low calcination temperatures.

Participation of Religious Leaders in Helping the Success of the Government's COVID-19 Vaccination Program

Participation of Religious Leaders in Helping the Success of the Government's COVID-19 Vaccination Program. The basic idea of this paper departs from observations in the virtual and real world, where certain people or groups are found who disagree with the need to be vaccinated. If the country's people reject the mandatory mass vaccination, which the government is discussing, it will take a long time to restore normal activities. This paper uses a descriptive qualitative method with a literature study approach. The description in this paper found some people's rejection of vaccines because their views or perceptions about COVID-19 influenced it. The government's hope to immediately carry out mass vaccinations for all Indonesian people must be balanced with maximum efforts to make it happen. This substantial effort can be made by providing massive education in the media, conducting public campaigns, and providing guarantees to vaccine recipients. On the other hand, the success of this vaccination program does not only depend on the government; all elements of society are expected to contribute in this regard, especially religious leaders. The manifestation of the involvement of religious leaders is by educating the congregation through the pulpit about vaccines. In addition, religious leaders must also set an example by participating in vaccinations and actively countering hoax news. The dominance of factual information about vaccines dominates mass lines on social media. ABSTRAKKeikutsertaan Pemuka Agama Dalam Membantu Mensukseskan Program Vaksinasi COVID-19 Pemerintah. Ide dasar tulisan ini berangkat dari pengamatan di dunia maya dan nyata, yang mana ditemukan orang-orang atau kelompok tertentu yang tidak menyetujui keharusan untuk divaksin. Apabila masyarakat tanah air kecenderungan menolak wajib vaksinasi masal yang diwacanakan oleh pemerintah, tentu akan lama memulihkan aktivitas normal kembali. Tulisan ini menggunakan metode kualitatif deskriptif dengan pendekatan studi literatur. Uraian pada tulisan ini ditemukan, penolakan sebagian orang terhadap vaksin karena dipengaruhi oleh pandangan atau persepsi mereka mengenai COVID-19. Harapan pemerintah untuk segera melakukan vaksinasi masal ke seluruh masyarakat tanah air, harus diimbangi upaya yang maksimal dalam mewujudkannya. Upaya konkret itu dapat dilakukan dengan pemberian edukasi secara masif di media, melakukan kampanye publik dan adanya jaminan kepada penerima vaksin. Disisi lain suksesnya program vaksinasi ini tidak hanya bergantung kepada pemerintah, semua elemen masyarakat diharapkan kontribusinya dalam hal ini terutama para pemuka agama. Wujud dari keterlibatan pemuka agama adalah dengan mengedukasi jemaat melalui mimbar tentang vaksin. Selain itu, pemuka agama juga harus memberi contoh dengan ikut divaksin, serta aktif mengcounter berita hoax agar dominasi berita faktual tentang vaksin menguasai lini massa di media sosial.

Microrobotic swarms and their robotic delivery applications offer new venues for gene therapy delivery

Over the past decade, microrobotic swarms and their robotic delivery applications have evolved substantially. This review looked at the current advances in microrobotics swarming, navigation, and localization, as well as their applications for targeted imaging-guided distribution. While a substantial effort has been proposed towards in-vivo controlled administration, several restrictions remain. Research opportunities and challenges are presented, with probable solutions on the horizon. Microrobotic Swarm, Controller and Integration of Imaging Modality. Integrating the swarm controller with in vivo imaging technologies is a requirement for in vivo delivery jobs. Trading between imaging and control systems, as well as developing a swarm control scheme based on current imaging systems, is hard to do. Research should focus on integrating swarm navigation and imaging into the same energy source. The toxicity threshold needed depends on where microrobotic swarms are employed. Before establishing therapeutic procedures, the swarms' biocompatibility and toxicity should be evaluated. Swarms in endovascular delivery applications may require a more complete toxicity evaluation, including a range of parameters such as materials, dose, and block size. Research opportunities include bridging customized therapy/delivery and imaging-guided swarm control.

Antenna Design for Microwave and Millimeter Wave Applications: Latest Advances and Prospects

Until recently, substantial effort has been devoted to new approaches and attempts to the design of antennas for microwave and millimeter-wave applications [...]

Análisis de propuestas de Educación Física en casa durante la suspensión de clases por la COVID-19 y orientaciones para su diseño en Educación Primaria (Analysis of Physical Education at home proposals during the suspension of face-to-face classes due to

El sistema educativo está tratando de responder de manera eficaz a los retos y cambios en materia educativa provocados por la COVID-19. El proceso de transición de una enseñanza predominantemente presencial a una virtual ha supuesto un esfuerzo considerable para el profesorado de Educación Física (EF) con la finalidad de adaptar el proceso de enseñanza-aprendizaje. No hay evidencias de estudios que hayan analizado las iniciativas de EF en casa realizadas por los docentes. Esta investigación tiene como objetivo analizar, desde una perspectiva curricular, diferentes propuestas de EF en casa con la finalidad de conocer sus características, compartir ejemplos de buenas prácticas y ofrecer al profesorado orientaciones útiles que les ayuden a diseñar propuestas de calidad en el futuro. Los resultados evidenciaron que el perfil predominante de actividad fue un ejercicio individual de carácter motriz centrado en el desarrollo de la condición física y presentada como un reto, donde el alumnado repite una secuencia específica de movimientos con ayuda de internet. Abstract. The education system attempts to effectively respond to the instructional changes and challenges caused by COVID-19. The adaptation process of predominantly face-to-face teaching to virtual one has involved a substantial effort for Physical Education (PE) teachers with the aim of adapting the teaching and learning process. To the best of our knowledge, no studies have analyzed the different at-home PE units done by teachers. This research aimed at examining, from a curricular perspective, distinct at-home PE proposals in order to ascertain their characteristics, share instances of good teaching practices, and provide teachers with useful guidelines to help them design quality proposals in the future. The results evidenced that the predominant activity profile was an individual motor exercise focused on physical fitness and introduced as a challenge, in which students repeat a specific movement sequence with the aid of the internet.