Transient execution attacks such as Spectre and Meltdown exploit speculative execution in modern microprocessors to leak information via cache side‐channels. Software solutions to defend against many ...transient execution attacks employ the lfence serialising instruction, which does not allow instructions that come after the lfence to execute out‐of‐order with respect to instructions that come before the lfence. However, errors and Trojans in the hardware implementation of lfence can be exploited to compromise the software mitigations that use lfence. The aforementioned security gap has not been identified and addressed previously. The authors provide a formal method solution that addresses the verification of lfence hardware implementation. The authors also show how hardware Trojans can be designed to circumvent lfence and demonstrate that their verification approach will flag such Trojans as well. The authors have demonstrated the efficacy of our approach using RSD, which is an open source RISC‐V based superscalar out‐of‐order processor.
Serialising instructions such as lfence are used to guard modern microprocessors against Spectre‐like transient execution attacks. However, bugs and Trojans can render the solution ineffective without impacting programme correctness. We provide a formal verification methodology which guarantees the integrity of the lfence instruction.
We define the digital economy as all economic activities conducted through the use of information technologies, including activities to create new markets, expand old ones, and produce digital goods ...and services. The digital economy has become a major driver of sustainable development and the transition towards a greener economy. However, studies show an unequal level of progress among cities, regions, and countries. Consequently, this paper explores the associations between socio-cultural factors (such as attitudes towards marriage/raising a family) and components of the digital economy (such as expenses/investment in ICT and the proportion of personal computers and the Internet in households). This study specifically examines twenty-two ethnic minority regions in Russia with data covering a five-year period. Using the Pearson correlation coefficient, the results show that socio-cultural factors including a large urban population and high divorce rates were positively associated with the digital economy, whereas a large rural population, higher birth rates, and higher natural population growth were negatively correlated with the digital economy.
Summary
The objective of this systematic review is to identify current computer‐assisted technologies used for managing patients with a need to re‐establish craniofacial appearance, subjective ...discomfort and stomatognathic function, and the extent of their clinical documentation. Electronic search strategies were used for locating clinical studies in MEDLINE through PubMed and in the Cochrane library, and in the grey literature through searches on Google Scholar. The searches for commercial digital products for use in oral rehabilitation resulted in identifying 225 products per November 2016, used for patient diagnostics, communication and therapy purposes, and for other computer‐assisted applications in context with oral rehabilitation. About one‐third of these products were described in about 350 papers reporting from clinical human studies. The great majority of digital products for use in oral rehabilitation has no clinical documentation at all, while the products from a distinct minority of manufacturers have frequently appeared in more or less scientific reports. Moore's law apply also to digital dentistry, which predicts that the capacity of microprocessors will continue to become faster and with lower cost per performance unit, and innovative software programs will harness these improvements in performance. The net effect is the noticeable short product life cycle of digital products developed for use in oral rehabilitation and often lack of supportive clinical documentation. Nonetheless, clinicians must request clinically meaningful information about new digital products to assess net benefits for the patients or the dental professionals and not accept only technological verbiage as a basis for product purchases.
OBJECTIVE To describe the length of exposure to screens and the prevalence of consumption of meals and snacks by Brazilian adolescents in front of screens. METHODS We evaluated 74,589 12 to 17-year ...old adolescents from 1,247 schools in 124 Brazilian municipalities. A self-administered questionnaire was used. Its segment regarding nutrition contained questions about using TV, computers, and video game systems, having meals while watching TV, and consuming snacks in front of screens. Consumption of meals and snacks in front of screens was analyzed according to the following variables: geographical region, gender, age range, type of school (public or private), and school shift. The prevalences and their respective 95% confidence intervals were estimated under a complex sampling design. RESULTS A great deal of the adolescents
(51.8% IC95% 50.7-53.0) corrected reported spending two or more hours a day in front of screens. That habit was more frequent among male adolescents, private school students, morning shift students, and students from Brazil's South region. More than half of the adolescents (56.6%, 95%CI 55.4-57.8) reported almost always or always having meals in front of TV, and 39.6% (95%CI 38.8-40.5) of them said they consumed snacks in front of screens exactly as often. Both situations were the most prevalent ones among the girls, who attended public schools and were from Brazil's Midwest region. CONCLUSIONS Length of exposure to screens and consumption of meals and snacks almost always or always in front of screens are high among Brazilian adolescents. It is necessary to develop strategies aiming to reduce the length of screen use, considering the media reality that children and adolescents have been experiencing from earlier and earlier ages. That context must therefore be analyzed in an indissociable way.
•Chip-based Ag/GO MISPE array monolithic columns coupled with HPLC-FLD was established.•Bisphenol A (BPA) and nonyl phenol (NP) in fish samples tested on chip was enriched over 113-flod and ...92-fold.•The column showed good binding capacity and selectivity, as well as removal effect of impurities.•The detection limits of this method were 2.4ngL−1 for BPA and 4.7ngL−1 for NP, respectively.•Those columns or chips can be reused at least 15 times with similar extraction efficiency.
An analytical technique for selective, simultaneous determination of bisphenol A (BPA) and nonyl phenol (NP) in fish samples was established by a solid-phase extraction chip integrated with array columns of dual-molecularly imprinted polymer-coated silver-modified graphene oxide (Ag/GO-dual-MISPE-chip). Ag/GO dual-molecularly imprinted polymers (Ag/GO-dual-MIPs) were synthesized by in situ polymerization using Ag/GO as the supporting matrix which extracted templates easily. The affinity and specificity on the Ag/GO-dual-MISPE monolithic column were also investigated. The array extraction chip showed high binding capacity and selectivity to BPA and NP, with the imprinting factors of BPA and NP reaching 2.6 and 2.9, respectively. Ag/GO-dual-MIPs were characterized by scanning electron microscopy and Fourier transform-infrared (FT-IR) spectroscopy. As Low as 2.4ngL−1 BPA and 4.7ngL−1 NP were detected by high performance liquid chromatography coupled with fluorescence detection. The enrichment factor was 113-fold for BPA and 92-fold for NP. Therefore, the chip-based array columns are feasibly applicable to facile extraction of BPA and NP and effective clean-up of impurities in fish samples.
A new star-shaped small molecule (Ml) with triphenylamine as electron donor (D) unit and 4,7-dithienyl-5,6-bis(n-octyloxy)2,1,3benzoselenadiazole as electron acceptor (A) unit was designed and ...synthesized. The relationship between the structure and properties was well investigated. M1 shows excellent solubility in common organic solvents, broad absorption (300-650 nm), good optical band gap (E.sub.g)(1.96 eV), and proper energy level. Meanwhile, we also investigated the performance of the organic solar cells (OSCs) based on M1 and PC.sub.61BM or PC.sub.71BM with different weight ratios, under the illumination of AM 1. 5G, 100mW/cm.sup.2 The OSCs based on the blend of M1 and PC.sub.71BM (1:2, w/w) exhibited the best device performance with a power conversion efficiency of 1.54%, an open-circuit voltage of 0.91 V, a short-circuit current density of 4.54 mA/cm.sup.2, and a fill factor of 37.2%.
This paper studies the cross-country diffusion of personal computers (PCs) and the Internet, and examines how the diffusive interactions across these technologies affect the evolution of the global ...digital divide. We adopt a generalized diffusion model that incorporates the impact of one technology's installed base on the diffusion of the other technology. We estimate the model on data from 26 developing and developed countries between 1991 and 2005. We find that the codiffusion effects between PCs and the Internet are complementary in nature and the impact of PCs on Internet diffusion is substantially stronger in developing countries as compared to developed ones. Furthermore, our results suggest that these codiffusive effects are a significant driver of the narrowing of the digital divide. We also examine the policy implications of our results, especially with respect to how complementarities in the diffusion of PC and Internet technologies might be harnessed to further accelerate the narrowing of the global digital divide.
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