Cache-Aided Non-Orthogonal Multiple Access

In this paper, we propose a novel joint caching and non-orthogonal multiple access (NOMA) scheme to facilitate advanced downlink transmission for next generation cellular networks. In addition to reaping the conventional advantages of caching and NOMA transmission, the proposed cache-aided NOMA scheme also exploits cached data for interference cancellation which is not possible with separate caching and NOMA transmission designs. Furthermore, as caching can help to reduce the residual interference power, several decoding orders are feasible at the receivers, and these decoding orders can be flexibly selected for performance optimization. We characterize the achievable rate region of cache-aided NOMA and investigate its benefits for minimizing the time required to complete video file delivery. Our simulation results reveal that, compared to several baseline schemes, the proposed cache-aided NOMA scheme significantly expands the achievable rate region for downlink transmission, which translates into substantially reduced file delivery times.Comment: Accepted for presentation at IEEE ICC 201

Cache-Aided Non-Orthogonal Multiple Access: The Two-User Case

In this paper, we propose a cache-aided non-orthogonal multiple access (NOMA) scheme for spectrally efficient downlink transmission. The proposed scheme not only reaps the benefits associated with NOMA and caching, but also exploits the data cached at the users for interference cancellation. As a consequence, caching can help to reduce the residual interference power, making multiple decoding orders at the users feasible. The resulting flexibility in decoding can be exploited for improved NOMA detection. We characterize the achievable rate region of cache-aided NOMA and derive the Pareto optimal rate tuples forming the boundary of the rate region. Moreover, we optimize cache-aided NOMA for minimization of the time required for completing file delivery. The optimal decoding order and the optimal transmit power and rate allocation are derived as functions of the cache status, the file sizes, and the channel conditions. Simulation results confirm that, compared to several baseline schemes, the proposed cache-aided NOMA scheme significantly expands the achievable rate region and increases the sum rate for downlink transmission, which translates into substantially reduced file delivery times.Comment: Accepted for publication in IEEE J. Sel. Topics Signal Process. arXiv admin note: text overlap with arXiv:1712.0955

Nanocrystal and surface alloy properties of bimetallic Gold-Platinum nanoparticles

We report on the correlation between the nanocrystal and surface alloy properties with the bimetallic composition of gold-platinum(AuPt) nanoparticles. The fundamental understanding of whether the AuPt nanocrystal core is alloyed or phase-segregated and how the surface binding properties are correlated with the nanoscale bimetallic properties is important not only for the exploitation of catalytic activity of the nanoscale bimetallic catalysts, but also to the general exploration of the surface or interfacial reactivities of bimetallic or multimetallic nanoparticles. The AuPt nanoparticles are shown to exhibit not only single-phase alloy character in the nanocrystal, but also bimetallic alloy property on the surface. The nanocrystal and surface alloy properties are directly correlated with the bimetallic composition. The FTIR probing of CO adsorption on the bimetallic nanoparticles supported on silica reveals that the surface binding sites are dependent on the bimetallic composition. The analysis of this dependence further led to the conclusion that the relative Au-atop and Pt-atop sites for the linear CO adsorption on the nanoparticle surface are not only correlated with the bimetallic composition, but also with the electronic effect as a result of the d-band shift of Pt in the bimetallic nanocrystals, which is the first demonstration of the nanoscale core-surface property correlation for the bimetallic nanoparticles over a wide range of bimetallic composition

Identifying Trustworthy Experts: How Do Policymakers Find and Assess Public Health Researchers Worth Consulting or Collaborating With?

This paper reports data from semi-structured interviews on how 26 Australian civil servants, ministers and ministerial advisors find and evaluate researchers with whom they wish to consult or collaborate. Policymakers valued researchers who had credibility across the three attributes seen as contributing to trustworthiness: competence (an exemplary academic reputation complemented by pragmatism, understanding of government processes, and effective collaboration and communication skills); integrity (independence, “authenticity”, and faithful reporting of research); and benevolence (commitment to the policy reform agenda). The emphases given to these assessment criteria appeared to be shaped in part by policymakers' roles and the type and phase of policy development in which they were engaged. Policymakers are encouraged to reassess their methods for engaging researchers and to maximise information flow and support in these relationships. Researchers who wish to influence policy are advised to develop relationships across the policy community, but also to engage in other complementary strategies for promoting research-informed policy, including the strategic use of mass media

Epidemiology and reporting characteristics of preclinical systematic reviews

In an effort to better utilize published evidence obtained from animal experiments, systematic reviews of preclinical studies are increasingly more common-along with the methods and tools to appraise them (e.g., SYstematic Review Center for Laboratory animal Experimentation [SYRCLE's] risk of bias tool). We performed a cross-sectional study of a sample of recent preclinical systematic reviews (2015-2018) and examined a range of epidemiological characteristics and used a 46-item checklist to assess reporting details. We identified 442 reviews published across 43 countries in 23 different disease domains that used 26 animal species. Reporting of key details to ensure transparency and reproducibility was inconsistent across reviews and within article sections. Items were most completely reported in the title, introduction, and results sections of the reviews, while least reported in the methods and discussion sections. Less than half of reviews reported that a risk of bias assessment for internal and external validity was undertaken, and none reported methods for evaluating construct validity. Our results demonstrate that a considerable number of preclinical systematic reviews investigating diverse topics have been conducted; however, their quality of reporting is inconsistent. Our study provides the justification and evidence to inform the development of guidelines for conducting and reporting preclinical systematic reviews

Coxiella burnetii in Humans and Ticks in Rural Senegal

Q fever is a zoonotic disease known since 1937. The disease may be severe, causing pneumonia, hepatitis and endocarditis. Q fever agent has been described as a possible biological weapon. Animals—especially domestic cows, goats and sheep—are considered reservoirs for this infection. They are capable of sustaining the infection for long periods and excreting viable bacteria, infecting other animals and, occasionally, humans. Here we studied the distribution of Q fever in a poorly studied region, Senegal. We studied the agent of Q fever both in ticks parasitizing domestic animals and in humans (antibodies in serum, bacteria in feces, saliva and milk). We found from the studied regions the bacterium is highly prevalent in rural Senegal. Up to 37.6% of five different and most prevalent tick species may carry the bacterium. Humans living in such areas, as other mammals, may occasionally excrete Q fever agent through feces and milk

On Hemangioblasts in Chicken

Hemangioblasts are bi-potential precursors for blood and endothelial cells (BCs and ECs). Existence of the hemangioblast in vivo by its strict definition, i.e. a clonal precursor giving rise to these two cell types after division, is still debated. Using a combination of mitotic figure analysis, cell labeling and long-term cell tracing, we show that, in chicken, cell division does not play a major role during the entire ventral mesoderm differentiation process after gastrulation. One eighth of cells do undergo at least one round of division, but mainly give rise to daughter cells contributing to the same lineage. Approximately 7% of the dividing cells that contribute to either the BC or EC lineage meet the criteria of true hemangioblasts, with one daughter cell becoming a BC and the other an EC. Our data suggest that hemangioblast-type generation of BC/EC occurs, but is not used as a major mechanism during early chicken development. It remains unclear, however, whether hemangioblast-like progenitor cells play a more prominent role in later development

Research misconduct in the fields of ethics and philosophy: researchers’ perceptions in Spain

This is the Author’s Original Manuscript (AOM) (also called a “preprint”) sent to review to Science and Engineering Ethics on 11/10/2020. The final version of the article was published online at SEE on 21/01/2021. The online version is available at: https://doi.org/10.1007/s11948-021-00278-wEmpirical studies have revealed a disturbing prevalence of research misconduct in a wide variety of disciplines, although not, to date, in the areas of ethics and philosophy. This study aims to provide empirical evidence on perceptions of how serious a problem research misconduct is in these two disciplines in Spain, particularly regarding the effects that the model used to evaluate academics’ research performance may have on their ethical behaviour. The methodological triangulation applied in the study combines a questionnaire, a debate at the annual meeting of scientific association, and in-depth interviews. Of the 541 questionnaires sent out, 201 responses were obtained (37.1% of the total sample), with a significant difference in the participation of researchers in philosophy (30.5%) and in ethics (52.8%); 26 researchers took part in the debate and 14 interviews were conducted. The questionnaire results reveal that 91.5% of the respondents considered research misconduct to be on the rise; 63.2% considered at least three of the fraudulent practices referred to in the study to be commonplace, and 84.1% identified two or more such practices. The researchers perceived a high prevalence of duplicate publication (66.5%) and self-plagiarism (59.0%), use of personal influence (57.5%) and citation manipulation (44.0%), in contrast to a low perceived incidence of data falsification or fabrication (10.0%). The debate and the interviews corroborated these data. Researchers associated the spread of these misconducts with the research evaluation model applied in Spain

Are researchers deliberately bypassing the technology transfer office? An analysis of TTO awareness

Most universities committed to the commercialization of academic research have established technology transfer offices (TTOs). Nonetheless, many researchers bypass these TTOs and take their inventions directly to the marketplace. While TTO bypassing has typically been portrayed as deliberate and undesirable behavior, we argue that it could be unintentional as many researchers may simply be unaware of the TTO’s existence. Taking an information-processing perspective and using data on 3250 researchers in 24 European universities, we examine researcher attributes associated with TTO awareness. Our evidence confirms that only a minority of researchers are aware of the existence of a TTO at their university. TTO awareness is greater among researchers who possess experience as entrepreneurs, closed many research and consulting contracts with industry partners, conduct research in medicine, engineering or life sciences, or occupy postdoctoral positions. Policy implications of these findings are discussed