•It is currently uncertain whether people with diabetes are at higher risk of severe illness from coronavirus disease 2019 (COVID-19).•We found that diabetes was associated with an approximately ...4-fold increased risk of having severe/critical COVID-19 illness.•This association was independent of age, sex, obesity, hypertension and smoking.•These findings highlight the urgent need for a multidisciplinary team-based approach to management of this patient population.
We present our study on the spatially resolved H and M* relation for 536 star-forming and 424 quiescent galaxies taken from the MaNGA survey. We show that the star formation rate surface density ( ), ...derived based on the H emissions, is strongly correlated with the M* surface density ( ) on kiloparsec scales for star-forming galaxies and can be directly connected to the global star-forming sequence. This suggests that the global main sequence may be a consequence of a more fundamental relation on small scales. On the other hand, our result suggests that ∼20% of quiescent galaxies in our sample still have star formation activities in the outer region with lower specific star formation rate (SSFR) than typical star-forming galaxies. Meanwhile, we also find a tight correlation between and for LI(N)ER regions, named the resolved "LI(N)ER" sequence, in quiescent galaxies, which is consistent with the scenario that LI(N)ER emissions are primarily powered by the hot, evolved stars as suggested in the literature.
•The total number of citations is growing annually by 5.6% and thus doubling every 12 years.•Citation inflation is a temporal bias resulting in significant measurement error, which is not addressed ...by extant normalization methods.•Citation inflation affects longitudinal analysis and comparison of units from different periods.•We outline method to obtain citation deflator index using the Web of Science search portal.•Citation-based research evaluation should be performed using deflated citation values.
Quantitative research evaluation requires measures that are transparent, relatively simple, and free of disciplinary and temporal bias. We document and provide a solution to a hitherto unaddressed temporal bias – citation inflation – which arises from the basic fact that scientific publication is steadily growing at roughly 4% per year. Moreover, because the total production of citations grows by a factor of 2 every 12 years, this means that the real value of a citation depends on when it was produced. Consequently, failing to convert nominal citation values into real citation values produces significant mis-measurement of scientific impact. To address this problem, we develop a citation deflator method, outline the steps to generalize and implement it using the Web of Science portal, and analyze a large set of researchers from biology and physics to demonstrate how two common evaluation metrics – total citations and h-index – can differ by a remarkable amount depending on whether the underlying citation counts are deflated or not. In particular, our results show that the scientific impact of prior generations is likely to be significantly underestimated when citations are not deflated, often by 100% or more of the nominal value. Thus, our study points to the need for a systemic overhaul of the counting methods used evaluating citation impact – especially in the case of researchers, journals, and institutions – which can span several decades and thus several doubling periods.
In practical engineering, a driving stress often exists and acts on the soil elements, and this stress may have a significant effect on the deformational characteristics and liquefaction resistance ...of sand when the sand is subjected to seismic loadings. This paper presents a systematic experimental investigation into the undrained cyclic behavior of saturated loose sand with the static shear under both triaxial compression and extension conditions. Various combinations of the magnitude of static stresses and cyclic stresses were considered in the triaxial tests. The results indicate that different static shear stress conditions lead to two distinct failure modes, namely, flow liquefaction and residual deformation failure. The required number of loading cycles for the onset of flow deformation and failure are both related to two stress parameters, i.e., cyclic stress ratio (CSR) and static stress ratio (SSR). In viewing the failure envelope established against the two stress variables CSR and SSR, a critical SSR that identifies the role of the presence of initial static shear stress is obtained: when SSR is less than that critical value, the resistance may increase, whereas the resistance may decrease as SSR becomes larger. In addition, the triggering conditions of flow deformation under cyclic loading can be interpreted with the instability response of sand under monotonic loading. Combined with the observation on the cyclic deviatoric strains developed during and after the flow deformation, a unified interpretation is made to quantify the effects of both the SSR and CSR on the cyclic resistance of loose sand.
•Two failure modes of saturated loose sand are identified.•The failure modes are affected by both the initial static stress and the cyclic stress.•The failure envelope of loose sand is established based on the test results.•The effect of flow deformation behavior on the cyclic resistance of loose sand is investigated.
In practical engineering, cyclic shear stresses induced by earthquakes, traffic, and waves are superimposed on the initial static shear stress in sand fills or deposits, leading to complex responses ...of soils such as their deformation characteristics, pore pressure generation, and susceptibility (or cyclic resistance) to liquefaction. To experimentally investigate the undrained cyclic response of saturated sand, a series of triaxial tests were performed, covering a broad range of initial static and cyclic deviatoric stress levels. The results indicate that different stress conditions lead to two types of cyclic behavior: cyclic mobility and residual deformation accumulation. The compressional static stress is beneficial to the cyclic resistance of the dense sand, whereas the extensional static stress is regarded as detrimental as it tended to reduce the cyclic strength. Moreover, by comparing the available test data obtained from the same sand with varying initial densities and confining pressures, the static shear effect on cyclic resistance was found to be dependent on the state of the sand. Compared to the interpretation made using the limiting pore pressure-based criterion, the conventional failure criterion using a cyclic axial strain of 5% may lead to a substantial overestimation of the cyclic resistance, thus resulting in unsafe assessment and design. Hence, by employing the pore pressure criterion, the pore pressure generated in the cyclic tests was investigated and was found to be significantly influenced by the static shear stress. A pore pressure generation model is proposed to obtain the pore pressure characteristics of sand under various static shear stress conditions.
Abstract
Semi-device-independent certification of an unsharp instrument has recently been demonstrated (2019
New J. Phys.
21
083034) based on the sequential sharing of quantum advantages in a ...prepare-measure communication game by assuming the system to be qubit. In this work, we provide device-independent (DI) self-testing of the unsharp instrument through the quantum violation of two Bell inequalities where the devices are uncharacterized and the dimension of the system remains unspecified. We introduce an elegant sum-of-squares approach to derive the dimension-independent optimal quantum violation of Bell inequalities which plays a crucial role. Note that the standard Bell test cannot self-test the post-measurement states and consequently cannot self-test unsharp instrument. The sequential Bell test possess the potential to self-test an unsharp instrument. We demonstrate that there exists a trade-off between the maximum sequential quantum violations of the Clauser–Horne–Shimony–Holt inequality, and they form an optimal pair that enables the DI self-testing of the entangled state, the observables, and the unsharpness parameter. Further, we extend our study to the case of elegant Bell inequality and we argue that it has two classical bounds—the local bound and the non-trivial preparation non-contextual bound, lower than the local bound. Based on the sharing of preparation contextuality by three independent sequential observers, we demonstrate the DI self-testing of two unsharpness parameters. Since an actual experimental scenario involves losses and imperfection, we demonstrate robustness of our certification to noise.
Improving or maintaining visual acuity is the main goal for the treatment of neovascular age-related macular degeneration (nAMD). Current nAMD standard of care dictates frequent intravitreal (IVT) ...anti–vascular endothelial growth factor (VEGF) injections, which places a substantial burden on patients, caregivers, and physicians. Brolucizumab, a newly developed anti-VEGF molecule for nAMD treatment, has demonstrated longer durability and improvement in visual and anatomic outcomes in clinical studies in a q12-week regimen, indicating its potential to reduce treatment burden as an important therapeutic tool in nAMD management. This review focuses on the development of brolucizumab and the preclinical and clinical studies evaluating its efficacy, tolerability, and safety. Brolucizumab (also known as “RTH258” and “ESBA1008”) is a humanized, single-chain variable fragment (scFv) antibody with a molecular mass of approximately 26 kDa that inhibits VEGF-A. Preclinical studies show that brolucizumab readily penetrates the retina to reach the retinal pigment epithelium (RPE)/choroid with minimal subsequent systemic exposure. The safety, tolerability, and efficacy of a single IVT brolucizumab administration in patients with treatment-naïve nAMD were first demonstrated in the SEE Phase 1/2 study. The OSPREY Phase 2 study showed brolucizumab to be as efficacious as aflibercept in a q8-week regimen with regard to best-corrected visual acuity (BCVA) and brolucizumab achieving greater fluid resolution. Brolucizumab-treated patients in the OSPREY study were subsequently challenged with a q12-week dosing interval, and the outcomes provided key information for the study design and end points of the Phase 3 studies. In the HAWK and HARRIER Phase 3 studies, after 3 monthly loading injections, brolucizumab treatment regimen (q12-week or q8-week) was guided by individual disease activity assessment using functional and anatomic parameters (central subfield thickness CST, intraretinal fluid IRF, or subretinal fluid SRF) versus aflibercept (q8-week). Fewer brolucizumab 6-mg treated eyes had disease activity versus aflibercept, and anatomic outcome results at weeks 16 and 48 demonstrate brolucizumab as a potent drying agent. Moreover, of patients treated with 6 mg brolucizumab, 55.6% and 51.0% maintained a q12-week dosing interval immediately after the loading phase until week 48 in HAWK and HARRIER, respectively. These Phase 3 studies demonstrated that the brolucizumab q12-week regimen maintains efficacy and safety while reducing treatment burden associated with regular IVT injections for patients with nAMD.
Smoothed particle hydrodynamics (SPH) is a Lagrangian method based on a meshless discretization of partial differential equations. In this review, we present SPH discretization of the Navier-Stokes ...and advection-diffusion-reaction equations, implementation of various boundary conditions, and time integration of the SPH equations, and we discuss applications of the SPH method for modeling pore-scale multiphase flows and reactive transport in porous and fractured media.
Reputation and impact in academic careers Petersen, Alexander Michael; Fortunato, Santo; Pan, Raj K. ...
Proceedings of the National Academy of Sciences - PNAS,
10/2014, Volume:
111, Issue:
43
Journal Article
Peer reviewed
Open access
Reputation is an important social construct in science, which enables informed quality assessments of both publications and careers of scientists in the absence of complete systemic information. ...However, the relation between reputation and career growth of an individual remains poorly understood, despite recent proliferation of quantitative research evaluation methods. Here, we develop an original framework for measuring how a publication’s citation rate Δ c depends on the reputation of its central author i , in addition to its net citation count c . To estimate the strength of the reputation effect, we perform a longitudinal analysis on the careers of 450 highly cited scientists, using the total citations C ᵢ of each scientist as his/her reputation measure. We find a citation crossover c ×, which distinguishes the strength of the reputation effect. For publications with c < c ×, the author’s reputation is found to dominate the annual citation rate. Hence, a new publication may gain a significant early advantage corresponding to roughly a 66% increase in the citation rate for each tenfold increase in C ᵢ. However, the reputation effect becomes negligible for highly cited publications meaning that, for c ≥ c ×, the citation rate measures scientific impact more transparently. In addition, we have developed a stochastic reputation model, which is found to reproduce numerous statistical observations for real careers, thus providing insight into the microscopic mechanisms underlying cumulative advantage in science.
Significance Over a scientist’s career, a reputation is developed, a standing within a research community, based largely upon the quantity and quality of his/her publications. Here, we develop a framework for quantifying the influence author reputation has on a publication’s future impact. We find author reputation plays a key role in driving a paper’s citation count early in its citation life cycle, before a tipping point, after which reputation has much less influence relative to the paper’s citation count. In science, perceived quality, and decisions made based on those perceptions, is increasingly linked to citation counts. Shedding light on the complex mechanisms driving these quantitative measures facilitates not only better evaluation of scientific outputs but also a more transparent evaluation of the scientists producing them.
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