scholarly journals Long-term dynamics of Norovirus transmission in Japan, 2005–2019

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e11769
Author(s):  
Megumi Misumi ◽  
Hiroshi Nishiura
Keyword(s):  
Natural History ◽  
Goodness Of Fit ◽  
Virus Detection ◽  
Asymptomatic Infection ◽  
Time Varying ◽  
Yearly Variation ◽  
Dominant Genotype ◽  
Over Time ◽  
Outbreak Size

Norovirus continues to evolve, adjusting its pathogenesis and transmissibility. In the present study, we systematically collected datasets on Norovirus outbreaks in Japan from 2005 to 2019 and analyzed time-dependent changes in the asymptomatic ratio, the probability of virus detection, and the probability of infection given exposure. Reports of 1,728 outbreaks were published, and feces from all involved individuals, including those with asymptomatic infection, were tested for virus in 434 outbreaks. We found that the outbreak size did not markedly change over this period, but the variance in outbreak size increased during the winter (November–April). Assuming that natural history parameters did not vary over time, the asymptomatic ratio, the probability of virus detection, and the probability of infection given exposure were estimated to be 18.6%, 63.3% and 84.5%, respectively. However, a model with time-varying natural history parameters yielded better goodness-of-fit and suggested that the asymptomatic ratio varied by year. The asymptomatic ratio was as high as 25.8% for outbreaks caused by genotype GII.4 noroviruses. We conclude that Norovirus transmissibility has not changed markedly since 2005, and that yearly variation in the asymptomatic ratio could potentially be explained by the circulating dominant genotype.

Flexible Design of Systems Considering Time-Dependent Reliability

2015 ◽  
Author(s):  
Vijitashwa Pandey ◽  
Zissimos P. Mourelatos ◽  
Annette Skowronska
Keyword(s):  
Time Dependent ◽  
Time Varying ◽  
Repairable Systems ◽  
Flexible Design ◽  
Change Over Time ◽  
New Approach ◽  
Hydrokinetic Turbine ◽  
The Future ◽  
Over Time

Many repairable systems degrade with time and are subjected to time-varying loads. Their characteristics may change over time considerably, making the assessment of their performance and hence their design difficult. To address this issue, we introduce in this paper the concept of flexible design of repairable systems under time-dependent reliability considerations. In flexible design, the system can be modified in the future to accommodate uncertain events. As a result, regardless of how uncertainty resolves itself, a modification is available that will keep the system close to optimal provided failure events have been properly characterized. We discuss how flexible design of repairable systems requires a fundamentally new approach and demonstrate its advantages using the design of a hydrokinetic turbine. Our results show that long-term metrics are improved when time-dependent characteristics and flexibility are considered together.

scholarly journals POPULATION DYNAMICS, AGGLOMERATION ECONOMIES AND MUNICIPAL SIZE: A LONG-TERM ANALYSIS

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Maria Teresa CIOMMI ◽  
laria ZAMBON ◽  
Luca SALVATI
Keyword(s):  
Population Dynamics ◽  
Spatial Distribution ◽  
Population Density ◽  
Spatial Heterogeneity ◽  
Goodness Of Fit ◽  
Basic Knowledge ◽  
Optimal Size ◽  
Administrative Units ◽  
Over Time

Under the hypothesis that modifications in municipal boundaries and creation (or suppression) of new administrative units reflect a progressive adjustment toward a more balanced distribution of population over space, the present study investigates the long-term relationship (1928-2012) between urban expansion, population dynamics and municipal area in a growing metropolitan region (Athens, Greece). In expanding regions, municipal size is a key variable outlining the amount and spatial concentration of services and infrastructures, resulting to be functionally related to population density, agglomeration factors, land availability to building and characteristic socioeconomic profiles of local communities. A statistical analysis of the relationship between population density and municipal area provides basic knowledge to policy and planning adjustments toward a more balanced spatial distribution of population and land among the local government units. Descriptive statistics, mapping, correlation analysis and linear regressions were used to assess the evolution of such relationship over a sufficiently long time period. The average municipal area in Athens decreased moderately over time, with a slight increase in spatial heterogeneity. Conversely, the average population density per municipality increased more rapidly, with a considerable reduction in spatial heterogeneity. The observed goodness-of-fit of the linear relationship between population density and municipal area increased significantly over time. The empirical results of our study indicate that municipal size has progressively adjusted to population density across metropolitan areas, determining a more balanced spatial distribution of the resident population, which was consolidated by the recent administrative reform of the local authorities in Greece (the so called ‘Kallikratis’ law). Such conditions represent a base for the informed analysis of the spatial structure of local administrative units and they contribute to the debate on the optimal size of municipalities and other administrative districts with relevant impact on both urban and metropolitan scales of governance.

Reduction of major amputations in the diabetic ischaemic foot: A strategy to "take control" with conservative care as well as revascularisation

VASA ◽  
2001 ◽  
Vol 30 (Supplement 58) ◽  
pp. 6-14 ◽  
Author(s):  
Edmonds ◽  
Foster
Keyword(s):  
Natural History ◽  
Treatment Plan ◽  
Staging System ◽  
Vascular Control ◽  
New Approach ◽  
Conservative Care ◽  
Arterial Bypass ◽  
Therapeutic Footwear ◽  
Frequent Problem

The diabetic ischaemic foot has become an increasingly frequent problem over the last decade. However, we report a new approach consisting of a basic classification, a simple staging system of the natural history and a treatment plan for each stage, within a multi-disciplinary framework. This approach of "taking control" consists of two parts: 1. long-term conservative care including debridement of ulcers (to obtain wound control), eradication of sepsis (micribiological control), and provision of therapeutic footwear (mechanical control), and 2. revascularisation by angioplasty and arterial bypass (vascular control). This approach has led to a 50% reduction in the rate of major amputations in patients attending with ischaemic ulceration and absent foot pulses from 1989 to 1999 (from 4.6% to 2.3% per year). Patients who underwent angioplasty increased from 6% to 13%. Arterial bypass similarly increased from 3% to 7% of cases. However, even with an increased rate of revascularisation, 80% of patients responded to conservative care alone. This,we conclude, is an essential part of the management of all patients with ischaemic feet.

The natural history of pituitary apoplexy: long term follow-up study

2019 ◽  
Author(s):  
Ayesha Shaikh ◽  
Natasha Shrikrishnapalasuriyar ◽  
Giselle Sharaf ◽  
David Price ◽  
Maneesh Udiawar ◽  
...  
Keyword(s):  
Natural History ◽  
Pituitary Apoplexy ◽  
Follow Up Study ◽  
Long Term Follow Up ◽  
History Of

Economic Institutions and Growth Nexus: The Role of Governance and Democratic Institutions—Evidence from Time Varying Parameters’ (TVPs) Models

2016 ◽  
Vol 55 (4I-II) ◽  
pp. 675-688
Author(s):  
Ghulam Murtaza ◽  
Muhammad Zahir Faridi
Keyword(s):  
Structural Changes ◽  
Jel Classification ◽  
Economic Institutions ◽  
Time Varying ◽  
Democratic Institutions ◽  
Main Hypothesis ◽  
Dynamic Relationship ◽  
Rolling Window

The present study has investigated the channels through which the linkage between economic institutions and growth is gauged, by addressing the main hypothesis of the study that whether quality of governance and democratic institutions set a stage for economic institutions to promote the long-term growth process in Pakistan. To test the hypothesis empirically, our study models the dynamic relationship between growth and economic institutions in a time varying framework in order to capture institutional developments and structural changes occurred in the economy of Pakistan over the years. Study articulates that, along with some customary specifics, the quality of government and democracy are the substantial factors that affect institutional quality and ultimately cause to promote growth in Pakistan. JEL Classification: O40; P16; C14; H10 Keywords: Economic Institutions, Growth, Governance and Democracy, Rolling Window Two-stage Least Squares, Pakistan

Robustness Over Time-Varying Channels in DNN-HMM ASR Based Human-Robot Interaction

2017 ◽  
Author(s):  
José Novoa ◽  
Jorge Wuth ◽  
Juan Pablo Escudero ◽  
Josué Fredes ◽  
Rodrigo Mahu ◽  
...  
Keyword(s):  
Human Robot Interaction ◽  
Time Varying ◽  
Robot Interaction ◽  
Time Varying Channels ◽  
Over Time

Enhancing community welfare through improved water quality: a case for applying staggered pollution charges in the river Musi sub-basin of Andhra Pradesh, India

Water Policy ◽  
2005 ◽  
Vol 7 (5) ◽  
pp. 469-483
Author(s):  
Tishya Chatterjee
Keyword(s):  
Andhra Pradesh ◽  
Relevant Literature ◽  
Pollution Prevention ◽  
Economic Benefits ◽  
Environmental Damage ◽  
Marginal Costs ◽  
Community Acceptance ◽  
Level Data ◽  
Over Time

In conditions of severe water-pollution and dormant community acceptance of accumulating environmental damage, the regulator's role goes beyond pollution prevention and more towards remediation and solutions based on the community's long-term expectations of economic benefits from clean water. This paper suggests a method to enable these benefits to become perceptible progressively, through participatory clean-up operations, supported by staggered pollution charges. It analyses the relevant literature on pollution prevention and applies a cost-based “willingness to pay” model, using primary basin-level data of total marginal costs. It develops a replicable demand-side approach imposing charge-standard targets over time in urban-industrial basins of developing countries.

Sign in / Sign up

Export Citation Format

Share Document