Even with over 80% of the population being vaccinated against COVID-19, the disease continues to claim victims. Therefore, it is crucial to have a secure Computer-Aided Diagnostic system that can ...assist in identifying COVID-19 and determining the necessary level of care. This is especially important in the Intensive Care Unit to monitor disease progression or regression in the fight against this epidemic. To accomplish this, we merged public datasets from the literature to train lung and lesion segmentation models with five different distributions. We then trained eight CNN models for COVID-19 and Common-Acquired Pneumonia classification. If the examination was classified as COVID-19, we quantified the lesions and assessed the severity of the full CT scan. To validate the system, we used Resnetxt101 Unet++ and Mobilenet Unet for lung and lesion segmentation, respectively, achieving accuracy of 98.05%, F1-score of 98.70%, precision of 98.7%, recall of 98.7%, and specificity of 96.05%. This was accomplished in just 19.70 s per full CT scan, with external validation on the SPGC dataset. Finally, when classifying these detected lesions, we used Densenet201 and achieved accuracy of 90.47%, F1-score of 93.85%, precision of 88.42%, recall of 100.0%, and specificity of 65.07%. The results demonstrate that our pipeline can correctly detect and segment lesions due to COVID-19 and Common-Acquired Pneumonia in CT scans. It can differentiate these two classes from normal exams, indicating that our system is efficient and effective in identifying the disease and assessing the severity of the condition.
Stability and nonlinear analyses were employed to study symmetric and asymmetric steady flows through a straight channel with a smooth constriction with 50 % occlusion. Linear stability analysis was ...carried out to determine the unstable regions and the critical Reynolds numbers for the primary and secondary global instabilities. The primary bifurcation demonstrated an intricate aspect: the three-dimensional modes transfer their energy to the two-dimensional mode, which causes a symmetry breaking of the flow. This behaviour could be observed for Reynolds number lower than the critical, showing that this primary bifurcation is hysteretical. The secondary bifurcation also presented subcritical behaviour, exhibiting a pitchfork diagram with a large hysteretic curve. Given the subcritical character of both bifurcations, the relevance of non-normal growth in these flows were assessed, so that their convective mechanisms were exhaustively investigated. In addition, we could show that, for the secondary instability, optimal initial disturbances with large enough initial energy were able to promote a subcritical nonlinear saturation for a Reynolds number lower than the critical. The physical mechanism behind the transition process occurred by nonlinear interaction between the two- and three-dimensional modes, which established oscillatory behaviour, moreover, this energy exchange between the modes led the flow to the nonlinear saturated state. Therefore, the two-dimensional modes play a key role in the primary and secondary bifurcations of this system.
Abstract
This study investigated the resistance to desiccation of two species of freshwater crabs, Dilocarcinus pagei and Sylviocarcinus pictus. Dilocarcinus pagei survived almost twice as long as S. ...pictus, 127 ± 82.4 h and 69 ± 17.5 h, respectively. The females of both species survived longer than the males and the females of D. pagei survived longer than the females of S. pictus. Water loss until death was on average 30.12 ± 11.79% for D. pagei and 42.59 ± 7.49% for S. pictus. Dilocarcinus pagei showed a lower water loss than S. pictus until death and large S. pictus females and small D. pagei females exhibited a higher water loss, with differences between species and sex. The results reveal how these two species of crabs behave in extreme droughts in the Amazon floodplain. The females of both species were more resistant, although females of D. pagei were more resistant to desiccation than females of S. pictus, showing a higher degree of terrestriality.
This article aims to set a framework on how venture capital could contribute comprehensively to supporting sustainable development goals employing Industry 4.0's digital entrepreneurship, filling a ...gap in the existing literature concerning the role of venture capital in Industry 4.0. This article advances a new venture capital model, which might play a significant role in OECD countries in supporting investment and innovative projects and allow for creative activity and high‐powered global competitiveness. Likewise, venture capital will achieve a new purpose to better economic well‐being and ensure higher effectiveness of venture capital management. The economic model here has shown that an increase of the share of venture capital in the structure of GDP by 1% leads to the growth of digital competitiveness by 60.0698 points and the development of global competitiveness by 2.3831 points. As per the article's findings, we should give venture capital a new role in supporting innovative projects, a digital modernization of entrepreneurship, and global competitiveness. These parts are connected to economic and public well‐being.
•Forest conservation has significant welfare costs that require compensation.•We test whether Discrete Choice Experiments (DCEs) can estimate these costs ex ante.•While DCE succeeded in eliciting ...current preferences, results were affected by respondents’ experience of conservation.•Caution is required if DCEs are used to estimate compensation ex ante.•Ensuring fair compensation for coercive conservation remains very challenging.
Protected areas may impose local welfare costs through the enforcement of use restrictions. Predicting their welfare impacts before their establishment could help with the design of compensation schemes. Discrete choice experiments (DCEs) are increasingly used for ex ante evaluations but their validity is largely untested in low-income settings. Using a case study of a new REDD+ (Reducing Emissions from Deforestation and forest Degradation) project in eastern Madagascar, we explore the validity of DCEs in two ways: (i) whether the estimates of welfare costs derived from DCE are affected by respondents’ prior experience of conservation (ii) whether DCE results have high theoretical and content validity. We surveyed households who have varying degrees of experience of restrictions to swidden agriculture. We also qualitatively debriefed a sub-sample of respondents to better understand their thought processes. Latent class analysis shows that DCE outcomes vary with conservation experience. Households more experienced with forest protection are less willing to trade-off rights to clear forest for swidden agriculture with any compensatory interventions whereas less experienced households highly favor support for alternative agricultural techniques and a secure right to clear one hectare of forest. Although the results show apparent non-attendance to some attributes (e.g., cash payments), qualitative debriefings suggest that respondents infact do expect relatively low or no utility from the given attributes and hence have theoretically valid preferences. Similarly, the DCE has generally high content validity. Although DCE can elicit current preferences in this context, using ex ante DCE to estimate the welfare costs of such a long-term intervention requires caution. We conclude that it is difficult to robustly estimate compensation in advance of an intervention, there is therefore a need to rethink conservation approaches, and the feasibility of achieving fair compensations for conservation-imposed restrictions.
A Generalized DFT Precoded Filter Bank System Junior, Rogerio Pereira; Rocha, Carlos A. F. da; Chang, Bruno S. ...
IEEE wireless communications letters,
06/2022, Letnik:
11, Številka:
6
Journal Article
Recenzirano
The discrete Fourier transform (DFT) can be used as a precoding technique in a filter bank system to partially recover complex orthogonality. In this work, a proposal is made to make the waveform ...design more flexible through the introduction of a parameter called rate factor. With this parameter, we generalize the DFT precoded filter bank system and modify the data transmission format when compared to the conventional system. Such modification allows for better resource allocation and lower PAPR. Furthermore, theoretical and simulation results show better error performance in high mobility scenarios.
Strategies to Deal with Terrorism Frey, Bruno S; Osterloh, Margit
CESifo economic studies,
12/2018, Letnik:
64, Številka:
4
Journal Article
Recenzirano
Abstract
Much of the research on terrorism has been devoted to analyzing and understanding the concept and consequences of terrorism, as well as the behavior of terrorists. In contrast, this article ...develops five new and concrete proposals for effective strategies against terrorism: (i) strengthening decentralization; (ii) encouraging fighters to leave the terrorist camp; (iii) reducing the incentives to enter terrorist groups; (iv) negotiating with terrorist groups; and (v) reducing media attention. The advantages and disadvantages of these strategies for curbing terrorism are discussed. They certainly are no panacea to solve terrorist threats. However, they are proposed, as possible ways to overcome the commonly propagated 'war against terrorism' proved to be of little effect, or even to be counterproductive. (JEL codes: D74, H56, K42).
This study reports the fabrication of high mass loading (32 mg/cm2) electrodes of niobium pentoxide (Nb2O5) nanoparticles and carbon nanotubes (CNTs) using a facile procedure. The as-obtained Nb2O5 ...nanoparticles by microwave-assisted hydrothermal synthesis presented pseudohexagonal (TT) phase, and when exposed to the thermal treatment, the Nb2O5 nanoparticles changed to orthorhombic (T) phase. Distinct morphologies were obtained, which exhibited a specific surface area of 216 m2/g and 47 m2/g to pseudohexagonal and orthorhombic phases, respectively. Cyclic voltammetry and electrochemical impedance spectroscopy techniques were performed in a three-electrode system using 1 M Li2SO4 as electrolyte with a potential window of 0–0.9 V (versus standard calomel electrode). Both materials showed capacitive behavior with a specific capacitance of 0.11 F/cm2 and 0.09 F/cm2 to nanocomposites CNT + TT-Nb2O5 and CNT + T-Nb2O5 at 2 mV/s, respectively. Thus, an efficient, simple, and promising process to produce electrodes for supercapacitors was demonstrated.
To evaluate the characteristics and outcomes of patients with cancer admitted to several intensive care units. Knowledge on patients with cancer requiring intensive care is mostly restricted to ...single-center studies.
: Prospective, multicenter, cohort study.
Intensive care units from 28 hospitals in Brazil.
A total of 717 consecutive patients included over a 2-mo period.
None.
There were 667 (93%) patients with solid tumors and 50 (7%) patients had hematologic malignancies. The main reasons for intensive care unit admission were postoperative care (57%), sepsis (15%), and respiratory failure (10%). Overall hospital mortality rate was 30% and was higher in patients admitted because of medical complications (58%) than in emergency (37%) and scheduled (11%) surgical patients (p < .001). Adjusting for covariates other than the type of admission, the number of hospital days before intensive care unit admission (odds ratio OR, 1.18; 95% confidence interval CI, 1.01-1.37), higher Sequential Organ Failure Assessment scores (OR, 1.25; 95% CI, 1.17-1.34), poor performance status (OR, 3.40; 95% CI, 2.19 -5.26), the need for mechanical ventilation (OR, 2.42; 95% CI, 1.51-3.87), and active underlying malignancy in recurrence or progression (OR, 2.42; 95% CI, 1.51-3.87) were associated with increased hospital mortality in multivariate analysis.
This large multicenter study reports encouraging survival rates for patients with cancer requiring intensive care. In these patients, mortality was mostly dependent on the severity of organ failures, performance status, and need for mechanical ventilation rather than cancer-related characteristics, such as the type of malignancy or the presence of neutropenia.
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