Aggregatibacter actinomycetemcomitans has been described as a member of the indigenous oral microbiota of humans, and is involved in the pathology of periodontitis and various non-oral infections. ...This bacterium selectively kills human leukocytes through expression of leukotoxin, a large pore-forming protein that belongs to the Repeat in Toxin (RTX) family. The specificity of the toxin is related to its prerequisite for a specific target cell receptor, LFA-1, which is solely expressed on leukocytes. The leukotoxin causes death of different leukocyte populations in a variety of ways. It activates a rapid release of lysosomal enzymes and MMPs from neutrophils and causes apoptosis in lymphocytes. In the monocytes/macrophages, the toxin activates caspase-1, a cysteine proteinase, which causes a proinflammatory response by the activation and secretion of IL-1β and IL-18. A specific clone (JP2) of A. actinomycetemcomitans with enhanced leukotoxin expression significantly correlates to disease onset in infected individuals. Taken together, the mechanisms by which this toxin kills leukocytes are closely related to the pathogenic mechanisms of inflammatory disorders, such as periodontitis. Therapeutic strategies targeting the cellular and molecular inflammatory host response in periodontal diseases might be a future treatment alternative.
Previous studies have linked personal characteristics of business leaders to corporate decisions and outcomes. We analyze if the traumatic experience of the Chinese Famine has an impact on managerial ...decisions. By exploiting the exogenous variation in local severity of the famine, we find that having lived through the famine during one's younger years is associated with more conservative financial, investment, and cash holding policies, a lower likelihood of unethical behavior, and better firm performance during economic downturns.
•We examine the relationship between experience of the Great Chinese Famine and managerial decisions.•Having lived through the famine is associated with more conservative corporate policies.•Having experienced the famine is associated with lower likelihood of unethical behavior.•Experience of the famine is also associated with better firm performance during economic downturns.
The transmission of infectious diseases is dependent on the amount and nature of contacts between infectious and healthy individuals. Confined and crowded environments that people visit in their ...day-to-day life (such as town squares, business districts, transport hubs, etc) can act as hot-spots for spreading disease. In this study we explore the link between the use of public transport and the spread of airborne infections in urban environments.
We study a large number of journeys on the London Underground, which is known to be particularly crowded at certain times. We use publically available Oyster card data (the electronic ticket used for public transport in Greater London), to infer passengers' routes on the underground network. In order to estimate the spread of a generic airborne disease in each station, we use and extend an analytical microscopic model that was initially designed to study people moving in a corridor.
Comparing our results with influenza-like illnesses (ILI) data collected by Public Health England (PHE) in London boroughs, shows a correlation between the use of public transport and the spread of ILI. Specifically, we show that passengers departing from boroughs with higher ILI rates have higher number of contacts when travelling on the underground. Moreover, by comparing our results with other demographic key factors, we are able to discuss the role that the Underground plays in the spread of airborne infections in the English capital.
Our study suggests a link between public transport use and infectious diseases transmission and encourages further research into that area. Results could be used to inform the development of non-pharmacological interventions that can act on preventing instead of curing infections and are, potentially, more cost-effective.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
We compare the technique of using the orbital angular momentum (OAM) of radio waves for generating multiple channels in a radio communication scenario with traditional multiple-in-multiple-out (MIMO) ...communication methods. We demonstrate that, for certain array configurations in free space, traditional MIMO theory leads to eigen-modes identical to the OAM states. From this we conclude that communicating over the sub-channels given by OAM states is a subset of the solutions offered by MIMO, and therefore does not offer any additional gains in capacity.
We study how Chinese private entrepreneurs benefit from participating in politics. Using original hand-collected data on listed firms controlled by private entrepreneurs, we document a significant ...positive relationship between political participation and subsequent change in firm performance. We also provide evidence that the change in social status cannot explain the change in performance. We then identify several ways through which firms gain preferential treatment when the controlling entrepreneur participates in politics: better access to debt financing, preferential tax treatment, more government subsidies, and superior access to regulated industries.
Social media platforms are becoming increasingly important channels for information dissemination. This study examines how microblogging by top executives affects the information environment for ...listed firms in an emerging market. Using a manually collected data set of Sina Weibo, one of China's most popular and largest social media platforms, we find that a board chair having a Weibo account is associated with the dissemination of more firm-specific information to the capital market. This result holds up to a battery of robustness tests, including an alternative noise-trading explanation and alternative measures of information flows and definitions of Weibo usage. We also show that the relationship between board chairs' Weibo usage and information dissemination is stronger for smaller firms, firms that went public more recently, and firms characterized by less analyst coverage. In addition, Weibo usage primarily disseminates firm-specific news rather than industry news. Finally, we document that institutional trading is an important channel through which private information is incorporated into stock prices. Findings in this study have important implications for the understanding of the role of social media in the dissemination process of corporate information and corporate communication strategy.
•We examine how microblogging by top executives affects the information environment for Chinese listed firms•Board chairs with a Weibo account are associated with dissemination of more firm-specific information to the capital market•The relationship is stronger for smaller firms, firms that went public more recently, and firms with less analyst coverage•Weibo usage primarily disseminates firm-specific news rather than industry news•Institutional trading is an important channel through which private information is incorporated into stock prices
A simultaneously accurate and computationally efficient parametrization of the potential energy surface of molecules and materials is a long-standing goal in the natural sciences. While atom-centered ...message passing neural networks (MPNNs) have shown remarkable accuracy, their information propagation has limited the accessible length-scales. Local methods, conversely, scale to large simulations but have suffered from inferior accuracy. This work introduces Allegro, a strictly local equivariant deep neural network interatomic potential architecture that simultaneously exhibits excellent accuracy and scalability. Allegro represents a many-body potential using iterated tensor products of learned equivariant representations without atom-centered message passing. Allegro obtains improvements over state-of-the-art methods on QM9 and revMD17. A single tensor product layer outperforms existing deep MPNNs and transformers on QM9. Furthermore, Allegro displays remarkable generalization to out-of-distribution data. Molecular simulations using Allegro recover structural and kinetic properties of an amorphous electrolyte in excellent agreement with ab-initio simulations. Finally, we demonstrate parallelization with a simulation of 100 million atoms.
It has been argued that the state sector is advancing at the cost of the private sector in China. To examine this issue, we conduct an empirical analysis in which we exploit the launch of a large ...stimulus programme in the autumn of 2008. We find that state-owned enterprises (SOEs) are better able to maintain their leverage levels and have better access to both short- and long-term debt compared with private firms after the introduction of the stimulus programme. We also find that preferential access to debt financing does not help SOEs improve their performance. Instead, SOEs perform significantly worse than private firms after the introduction of the stimulus programme. Moreover, political connections obtained through political participation help mitigate the discrimination that private firms face from Chinese banks and help improve firm performance. These results support the conjecture that China's state sector is advancing, with negative consequences for aggregate performance in the economy.
In this paper, we examine the impact of foreign direct investment (FDI) on local urban inequality in China. Specifically, we consider the FDI policy change as an exogenous shock on the local labour ...markets. We find that cities that have experienced a bigger policy change in promoting FDI between 1997 and 2002 are significantly more unequal in 2005. This pattern is mainly driven by the positive association between FDI liberalisation and skill premia. The result holds after we control for other policy changes, such as privatisation of state‐owned enterprises, infrastructure and trade liberalisation. We then turn to investigate the mechanisms using firm and individual‐level information. Our firm‐level evidence shows that FDI firms not only hire relatively more high‐skilled workers but also provide relatively higher wages to high‐skilled workers compared to domestic firms. Moreover, the individual‐level analysis shows that FDI has a significantly positive spillover effect on wages received by skilled workers employed by state‐owned enterprises, but not wages of unskilled workers.
Abstract
Background
Fluoroquinolones lack approval for treatment of tularemia but have been used extensively for milder illness. Here, we evaluated fluoroquinolones for severe illness.
Methods
In an ...observational study, we identified case-patients with respiratory tularemia from July to November 2010 in Jämtland County, Sweden. We defined severe tularemia by hospitalization for >24 hours and severe bacteremic tularemia by Francisella tularensis subsp. holarctica growth in blood or pleural fluid. Clinical data and drug dosing were retrieved from electronic medical records. Chest images were reexamined. We used Kaplan–Meier curves to evaluate time to defervescence and hospital discharge.
Results
Among 67 case-patients (median age, 66 years; 81% males) 30-day mortality was 1.5% (1 of 67). Among 33 hospitalized persons (median age, 71 years; 82% males), 23 had nonbacteremic and 10 had bacteremic severe tularemia. Subpleural round consolidations, mediastinal lymphadenopathy, and unilateral pleural fluid were common on chest computed tomography. Among 29 hospitalized persons with complete outcome data, ciprofloxacin/levofloxacin (n = 12), ciprofloxacin/levofloxacin combinations with doxycycline and/or gentamicin (n = 11), or doxycycline as the single drug (n = 6) was used for treatment. One disease relapse occurred with doxycycline treatment. Treatment responses were rapid, with median fever duration 41.0 hours in nonbacteremic and 115.0 hours in bacteremic tularemia. Increased age-adjusted Charlson comorbidity index predicted severe bacteremic tularemia (odds ratio, 2.7 per score-point; 95% confidence interval, 1.35–5.41). A 78-year-old male with comorbidities and delayed ciprofloxacin/gentamicin treatment died.
Conclusions
Fluoroquinolone treatment is effective for severe tularemia. Subpleural round consolidations and mediastinal lymphadenopathy were typical findings on computed tomography among case-patients in this study.
In an observational study of severe respiratory tularemia acquired by inhalation of Francisella tularensis aerosols, ciprofloxacin and levofloxacin appeared to be highly effective for treatment. Results were consistent between bacteremic and nonbacteremic illness.
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