scholarly journals Outbreaks of H5N1 in poultry in Thailand: the relative role of poultry production types in sustaining transmission and the impact of active surveillance in control

2012 ◽  
Vol 9 (73) ◽  
pp. 1836-1845 ◽  
Author(s):  
Patrick Walker ◽  
Simon Cauchemez ◽  
Nienke Hartemink ◽  
Thanawat Tiensin ◽  
Azra C. Ghani
Keyword(s):  
Active Surveillance ◽  
Outbreak Detection ◽  
Relative Role ◽  
Poultry Production ◽  
Commercial Farms ◽  
Spatio Temporal ◽  
Spread Of Infection ◽  
Backyard Flocks ◽  
The Impact

H5N1, highly pathogenic avian influenza, continues to pose a public health risk in the countries of southeast Asia where it has become endemic. However, in Thailand, which experienced two of the largest recorded epidemics in 2004–2005, the disease has been successfully reduced to very low levels. We fitted a spatio-temporal model of the spread of infection to outbreak data collected during the second wave of outbreaks to assess the extent to which different poultry types were responsible for propagating infection. Our estimates suggest that the wave of outbreaks would not have been possible without the contribution of backyard flocks to the susceptibility of a sub-district. However, we also estimated that outbreaks involving commercial poultry, a much larger sector in Thailand than in neighbouring countries, were disproportionately infectious, a factor which was also crucial in sustaining the wave. As a result, implemented measures that aim to reduce the role of commercial farms in the spread of infection, such as the drive to bring aspects of the supply chain ‘in house’, may help to explain the subsequent success in controlling H5N1 in Thailand. We also found that periods of active surveillance substantially improved the rate of outbreak detection.

scholarly journals Simulated retreat of Jakobshavn Isbræ since the Little Ice Age controlled by geometry

2018 ◽  
Vol 12 (7) ◽  
pp. 2249-2266 ◽  
Author(s):  
Nadine Steiger ◽  
Kerim H. Nisancioglu ◽  
Henning Åkesson ◽  
Basile de Fleurian ◽  
Faezeh M. Nick
Keyword(s):  
Little Ice Age ◽  
Ice Age ◽  
Climate Forcing ◽  
Relative Role ◽  
Regional Warming ◽  
History Of ◽  
The Impact ◽  
Term Response

Abstract. Rapid retreat of Greenland's marine-terminating glaciers coincides with regional warming trends, which have broadly been used to explain these rapid changes. However, outlet glaciers within similar climate regimes experience widely contrasting retreat patterns, suggesting that the local fjord geometry could be an important additional factor. To assess the relative role of climate and fjord geometry, we use the retreat history of Jakobshavn Isbræ, West Greenland, since the Little Ice Age (LIA) maximum in 1850 as a baseline for the parameterization of a depth- and width-integrated ice flow model. The impact of fjord geometry is isolated by using a linearly increasing climate forcing since the LIA and testing a range of simplified geometries. We find that the total length of retreat is determined by external factors – such as hydrofracturing, submarine melt and buttressing by sea ice – whereas the retreat pattern is governed by the fjord geometry. Narrow and shallow areas provide pinning points and cause delayed but rapid retreat without additional climate warming, after decades of grounding line stability. We suggest that these geometric pinning points may be used to locate potential sites for moraine formation and to predict the long-term response of the glacier. As a consequence, to assess the impact of climate on the retreat history of a glacier, each system has to be analyzed with knowledge of its historic retreat and the local fjord geometry.

Weathering the Soviet Countryside: The Impact of Climate and Agricultural Policies on Russian Grain Yields, 1958–2010

2013 ◽  
Vol 40 (1) ◽  
pp. 115-143 ◽  
Author(s):  
Nikolai M. Dronin ◽  
Andrei P. Kirilenko
Keyword(s):  
Large Scale ◽  
State Level ◽  
Relative Role ◽  
Agricultural Policies ◽  
Production Potential ◽  
Russian Agriculture ◽  
Land Privatization ◽  
History Of ◽  
The Impact

Agriculture in Russia has always had to contend with unfavorable climate. At the same time, large-scale socio-economic experiments have also strained the country’s food production potential throughout the 20th century. The relative role of climate and state agricultural policies in affecting production of cereals was studied for the period of 1958–2010. The study used statistical yield modeling to explain the variations in observed yields with slowly changing progress in technology and management and weather variability. The correlation between the actual and weather-explained yields is moderate to high: measured at the level of the entire country, Pearson’s r is 0.74 and Spearman’s rho is 0.68. Further, we suggest that the residual yield variability can be explained partially with the influence of large-scale changes in agricultural policies at the state level. Between these policies, we consider the following key periods in the history of Russian agriculture: “Virgin Lands” campaign (end of 1950s), Kosygin-Liberman initiatives (late 1960s), Brezhnev’s investment programmes in response of stagnation of agriculture (late 1970s – early 1980s), Gorbachev’s “Perestrojka” (1985–1991), and land privatization and price liberalization (1990s).

scholarly journals On the Role of Different Age Groups and Pertussis Vaccines During the 2012 Outbreak in Wisconsin

2018 ◽  
Vol 5 (5) ◽  
Author(s):  
Edward Goldstein ◽  
Colin J Worby ◽  
Marc Lipsitch
Keyword(s):  
Protective Effect ◽  
Age Groups ◽  
Vaccination Status ◽  
Relative Role ◽  
Age Group ◽  
Limited Information ◽  
Infection Transmission ◽  
Status Analysis ◽  
The Impact

Abstract Background There is limited information on the roles of different age groups in propagating pertussis outbreaks, and on the impact of vaccination on pertussis transmission in the community. Methods The relative roles of different age groups in propagating the 2012 pertussis outbreak in Wisconsin were evaluated using the relative risk (RR) statistic that measures the change in the group’s proportion among all detected cases before vs after the epidemic peak. The impact of vaccination in different age groups against infection (that is potentially different from the protective effect against detectable disease) was evaluated using the odds ratios (ORs), within each age group, for being vaccinated vs undervaccinated before vs after the outbreak’s peak. Results The RR statistic suggests that children aged 13–14 years played the largest relative role during the outbreak’s ascent (with estimates consistent across the 3 regions in Wisconsin that were studied), followed by children aged 7–8, 9–10, and 11–12 years. Young children and older teenagers and adults played more limited relative roles during the outbreak. Results of the vaccination status analysis for the fifth dose of DTaP (for children aged 7–8 years: OR, 0.44; 95% confidence interval [CI], 0.23–0.86; for children aged 9–10 years: OR, 0.51; 95% CI, 0.27–0.95); and for Tdap for children aged 13–14 years (OR, 0.38, 95% CI, 0.16–0.89) are consistent with protective effect against infection. Conclusions While our epidemiological findings for the fifth dose of DTaP and for Tdap are consistent with protective effect against infection, further studies, including those estimating vaccine effectiveness against infection/transmission to others particularly for pertussis vaccines for adolescents, are needed to evaluate the impact of vaccination on the spread of pertussis in the community.

scholarly journals Lithology and orographic precipitation control river incision in the tropical Andes

2019 ◽  
Author(s):  
Benjamin Campforts ◽  
Veerle Vanacker ◽  
Frédéric Herman ◽  
Matthias Vanmaercke ◽  
Wolfgang Schwanghart ◽  
...  
Keyword(s):  
Amazon Basin ◽  
Rainfall Variability ◽  
Orographic Precipitation ◽  
Natural Environments ◽  
Relative Role ◽  
Tropical Andes ◽  
River Incision ◽  
Bedrock River Incision ◽  
The Impact

Abstract. Process-based geomorphic transport laws enable to assess the impact of rainfall variability on bedrock river incision over geological timescales. However, isolating the role of rainfall variability on erosion remains difficult in natural environments in part because the variability of rock strength and its resistance to incision are poorly constrained. Here, we explore spatial differences in the rate of bedrock river incision in the Tropical Andes. The Ecuadorian Andes are characterized by strong rainfall gradients due to orographic precipitation sourced in the Amazon basin. In addition, the tectonic configuration has generated a profound lithological heterogeneity. The relative role of either these controls in modulating river incision on millennial time scales, however, remains unclear. Using 10Be catchment-wide erosion rates, meteorological and hydrological data, as well as data on bedrock erodibility, we provide quantitative constraints on the importance of rainfall variability and lithological variations. Explicit incorporation of rock erodibility in river incision models predicated on the stream power equation enables us to identify a first order control of lithology on river incision rates. Rainfall variability based on a spatially and temporally explicit hydrological dataset and a stochastic-threshold river incision model explain regional differences in river incision that cannot be attributed to topographical and/or lithological variability.

Impact on ozone of high-speed stratospheric aircraft: effects of the emission scenario

1994 ◽  
Vol 12 (10/11) ◽  
pp. 996-1005 ◽  
Author(s):  
G. Pitari ◽  
S. Palermi ◽  
G. Visconti
Keyword(s):  
High Speed ◽  
Stratospheric Ozone ◽  
Aerosol Layer ◽  
Relative Role ◽  
Nitric Oxides ◽  
Emissions Scenarios ◽  
Odd Nitrogen ◽  
The Impact ◽  
Emission Index

Abstract. A photochemical-transport two-dimensional model has been used to assess the impact of a projected fleet of high-speed stratospheric aircraft using different emissions scenarios. It is shown that the presence in the background atmosphere of nitric acid trihydrate aerosols is responsible for a lower stratospheric denoxification in addition to that caused by the sulfate aerosol layer. This has the effect of further decreasing the relative role of the odd nitrogen catalytic cycle for ozone destruction, so that the lower stratosphere is primarily controlled by chlorine species. The effect of aircraft injection of nitric oxides is that of decreasing the level of ClO, so that the lower stratospheric ozone (below about 20-25 km altitude) increases. The net effect on global ozone is that of a small increase even at Mach 2.4, and is enhanced by adopting emission scenarios including altitude restriction at 15 or 18 km. Reductions of the emission index (EI) of nitric oxides below relatively small values (about 15) are shown to reduce the aircraft-induced ozone increase, because of the associated smaller decrease of ClO. This conclusion is no more valid when the emission index is raised at the present values (about 45).

scholarly journals Trypanosoma evansiand Surra: A Review and Perspectives on Transmission, Epidemiology and Control, Impact, and Zoonotic Aspects

2013 ◽  
Vol 2013 ◽  
pp. 1-20 ◽  
Author(s):  
Marc Desquesnes ◽  
Alan Dargantes ◽  
De-Hua Lai ◽  
Zhao-Rong Lun ◽  
Philippe Holzmuller ◽  
...  
Keyword(s):  
The Philippines ◽  
Trypanosoma Evansi ◽  
Basic Knowledge ◽  
Mechanical Transmission ◽  
Relative Role ◽  
Disease Epidemiology ◽  
Worldwide Distribution ◽  
Transmission Modes ◽  
The Impact

This paper reviews the transmission modes ofTrypanosoma evansi. Its worldwide distribution is attributed to mechanical transmission. While the role of tabanids is clear, we raise questions on the relative role ofHaematobiasp. and the possible role ofStomoxyssp. in delayed transmission. A review of the available trypanocidal drugs and their efficacy in various host species is useful for understanding how they interact in disease epidemiology, which is complex. Although there are similarities with other mechanically transmitted trypanosomes,T. evansihas a more complex epidemiology due to the diversity of its hosts and vectors. The impact of clinical and subclinical disease is difficult to establish. A model was developed for buffaloes in the Philippines, which could be transferred to other places and livestock systems. SinceTrypanosoma evansiwas reported in humans, further research is required to investigate its zoonotic potential. Surra remains a potentially emerging disease that is a threat to Australia, Spain, and France. A number of questions about the disease have yet to be resolved. This brief review of the basic knowledge ofT. evansisuggests that there is renewed interest in the parasite, which is spreading and has a major economic impact.

Inflammation disrupts epithelial barrier function and induces the release of different populations of exosomes

2020 ◽  
Vol 30 (Supplement_2) ◽  
Author(s):  
B Martins ◽  
T Rodrigues ◽  
J Ramalho ◽  
A Ambrósio ◽  
H Girão ◽  
...  
Keyword(s):  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Primary Cultures ◽  
Age Related Macular Degeneration ◽  
Relative Role ◽  
Rpe Cells ◽  
Age Related ◽  
Different Populations ◽  
The Impact

Abstract Introduction Age-related macular degeneration (AMD) is a degenerative retinal disease that affects central vision. Most of their phenotypical features are believed to be associated with the dysfunction of retinal pigment epithelium (RPE). The accumulation of damaged proteins in aged RPE is associated with disruption of proteolytic pathways and exocytic activity, with release of intracellular proteins via exosomes (Exo), that are important players in intercellular communication and can contribute to disease progression. However, the impact of their secretion by polarized RPE on outer blood retinal barrier (oBRB) breakdown remains largely elusive Objectives Our aim was to explore the role of inflammation on the loss of RPE integrity and to understand the relative role of directional secretion of Exo by RPE in the loss of polarity and barrier disruption Methodology We used a human RPE cell line (ARPE-19), highly polarized RPE primary cultures (pRPE) and porcine eyecups. To mimic the inflammatory conditions present in AMD, cells were treated with two inflammatory stimuli, TNF (10 ng/mL) or LPS (100 ng/mL) Results TNF and LPS do not affect the viability of the RPE cells. RPE cells developed a confluent monolayer and reached a relatively constant TER of about 40 Ω/cm2 (ARPE-19) or higher than 150 Ω/cm2 (pRPE). Treatment with TNF significantly reduces the TER, decreased immunoreactivity and co-localization of the TJ proteins ZO-1 and occludin and increases MMP-2/-9 activity in the medium. Apical Exo isolated from the RPE cells are enriched in CD63 compared to the basolateral Exo, that are enriched in CD81. The Exo isolated from porcine eyecups, especially with the LPS stimulus, are enriched in CD81 and MMP-2 but have similar levels of CD63 Conclusion Overall, our results show that inflammation induces loss of RPE integrity and release of different populations of Exo. The unravelling of novel drug targets paves the way for development of new therapeutic strategies for AMD.

scholarly journals Will Medical Technology Deskill Doctors?

2016 ◽  
Vol 9 (7) ◽  
pp. 130 ◽  
Author(s):  
Jingyan Lu
Keyword(s):  
Professional Development ◽  
Health Care ◽  
Medical Education ◽  
Medical Technology ◽  
Clinical Evidence ◽  
Relative Role ◽  
Clinical Knowledge ◽  
Professional Development Training ◽  
The Impact

<p class="apa">This paper discusses the impact of medical technology on health care in light of the fact that doctors are becoming more reliant on technology for obtaining patient information, making diagnoses and in carrying out treatments. Evidence has shown that technology can negatively affect doctor-patient communications, physical examination skills, and development of clinical knowledge. We propose three possible approaches to medical education and professional development to assist human doctors in acquiring a better understanding of the relative role of technology. The approaches include providing undergraduate and professional development training on using medical technology, helping students recognize the importance of clinical evidence, and helping doctors establish autonomy while interfacing with medical technology.</p>

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