scholarly journals Stability of temperatures from TIMED/SABER v1.07 (2002–2009) and Aura/MLS v2.2 (2004–2009) compared with OH(6-2) temperatures observed at Davis Station, Antarctica

2010 ◽  
Vol 10 (9) ◽  
pp. 21547-21565 ◽  
Author(s):  
W. J. R. French ◽  
F. J. Mulligan

Abstract. Temperature profiles from two satellite instruments – TIMED/SABER and Aura/MLS – have been used to calculate hydroxyl-layer equivalent temperatures for comparison with values measured from OH(6-2) emission lines observed by a ground-based spectrometer located at Davis Station, Antarctica (68° S, 78° E). The profile selection criteria – <500 km from the ground station and solar zenith angles >97° – yielded a total of 2359 SABER profiles over 8 years (2002–2009) and 7407 MLS profiles over 5.5 years (2004–2009). The availability of simultaneous OH volume emission rate (VER) profiles from the SABER (OH-B channel) enabled an assessment of the impact of several different weighting functions in the calculation of OH-equivalent temperatures. The maximum difference between all derived hydroxyl layer equivalent temperatures was less than 3 K. Restricting the miss-distance and miss-time criteria showed little effect on the bias, suggesting that the OH layer is relatively uniform over the spatial and temporal scales considered. However, a significant trend was found in the bias between SABER and Davis OH of ~0.7 K/year over the 8-year period with SABER becoming warmer compared with the Davis OH temperatures. In contrast, Aura MLS exhibited a cold bias of 9.9 ± 0.4 K compared with Davis OH, but importantly, the bias remained constant over the 2004–2009 year period examined. The difference in bias behaviour of the two satellites has significant implications for multi-annual and long-term studies using their data.

2010 ◽  
Vol 10 (23) ◽  
pp. 11439-11446 ◽  
Author(s):  
W. J. R. French ◽  
F. J. Mulligan

Abstract. Temperature profiles from two satellite instruments – TIMED/SABER and Aura/MLS – have been used to calculate hydroxyl-layer equivalent temperatures for comparison with values measured from OH(6-2) emission lines observed by a ground-based spectrometer located at Davis Station, Antarctica (68° S, 78° E). The profile selection criteria – miss-distance <500 km from the ground station and solar zenith angles >97° – yielded a total of 2359 SABER profiles over 8 years (2002–2009) and 7407 MLS profiles over 5.5 years (2004–2009). The availability of simultaneous OH volume emission rate (VER) profiles from the SABER (OH-B channel) enabled an assessment of the impact of several different weighting functions in the calculation of OH-equivalent temperatures. The maximum difference between all derived hydroxyl layer equivalent temperatures was less than 3 K. Restricting the miss-distance and miss-time criteria showed little effect on the bias, suggesting that the OH layer is relatively uniform over the spatial and temporal scales considered. However, a significant trend was found in the bias between SABER and Davis OH of ~0.7 K/year over the 8-year period with SABER becoming warmer compared with the Davis OH temperatures. In contrast, Aura/MLS exhibited a cold bias of 9.9 ± 0.4 K compared with Davis OH, but importantly, the bias remained constant over the 2004–2009 year period examined. The difference in bias behaviour of the two satellites has significant implications for multi-annual and long-term studies using their data.


2021 ◽  
Vol 28 ◽  
Author(s):  
Douglas Henrique Pereira Damasceno ◽  
Arthur Aguiar Amaral ◽  
Cecília Andrade Silva ◽  
Ana Cristina Simões e Silva

Background: The COVID-19 pandemic demanded a global effort towards quickly developing safe and effective vaccines against SARS-CoV-2. Objective: This review aimed to discuss the main vaccines available, their mechanisms of action, results of clinical trials and epidemiological behavior. The implications of viral variants were also debated. Methods: A non-systematic literature review was performed between February and March 2021 by searching the Pubmed, Scopus, and SciELO databases, using different combinations of the following terms: "vaccines", "clinical trials" , "SARS-CoV-2", "Coronavirus", "COVID-19", "mechanisms of action". Data regarding clinical trials of SARS-CoV-2 vaccines and epidemiological information were also searched. Results: The mechanisms of action included vector-virus, mRNA and inactivated virus vaccines. The vaccines showed positive results in phases 2/3 clinical trials. The efficacy of the mRNA 1273 and of mRNA BNT 162b2 vaccines were 94.1% and 95%, respectively. The effectiveness of the ChAdOx1 nCoV-19 vaccine varied according to the scheme, with an overall value of 70.4%. The Gam-COVID-Vac vaccine had an efficacy of 91.6%. Regarding the Ad26.COV2.S vaccine, 99% or more of seroconversion was observed in all subgroups 29 days after vaccination. The CoronaVac vaccine induced an immune response in 92% of the volunteers receiving 3ug and in 98% with 6ug, in comparison to 3% in the placebo group. Conclusion: Global efforts have resulted in vaccines available in record time, with good safety and immunogenicity profile. However, only long-term studies can provide more information on duration of immunity and the need for additional doses.


2020 ◽  
Vol 73 (10) ◽  
pp. 2193-2197
Author(s):  
Oleksandr P. Volosovets ◽  
Tetyana O. Kryuchko ◽  
Viktor L. Veselskyi ◽  
Sergii P. Kryvopustov ◽  
Tetiana M. Volosovets ◽  
...  

The aim: Of the work was to study 25-year trends in the incidence of congenital anomalies in the child population of Ukraine in order to determine the impact of ecotoxic environmental factors on their development, in particular radiation. Materials and methods: Methods of statistical assessment, epidemiological analysis of materials at the Center for Medical Statistics of the MOH of Ukraine were used. Results: The rate of congenital anomalies growth for the recent 25 years has exceeded the growth rate of the total incidence in the child population of Ukraine by 1.6 times, occupying the leading place in Europe by the level of environment pollution. Over the last 25 years, the growth of the Ukrainian children’s congenital anomalies incidence level by 59.5% is observed, mostly in children from large industrial regions of Ukraine, due to the significant ecotoxic effect of pollutants on the child’s body. Children living permanently in the areas contaminated by the Chernobyl accident had significantly higher rates of congenital anomalies in 1986 than in the early 1990s, but over the recent 25 years the incidence in this contingent has decreased. Conclusions: The results of such long-term studies performed by a group of leading Ukrainian scientists from different regions of Ukraine indicate that in children experiencing negative effects of ecotoxic factors, including radiation, an increase in the detection and prevalence of congenital defects is observed, which requires complex international and intersectoral measures to prevent and reduce child mortality.


2021 ◽  
Author(s):  
Boris Gailleton ◽  
Luca Malatesta ◽  
Jean Braun ◽  
Guillaume Cordonnier

&lt;p&gt;Many laws have been developed to describe the different aspects of landscape evolution at large spatial and temporal scales. Natural landscapes have heterogeneous properties (lithologies, climates, tectonics, etc.) that are associated with multiple coexisting processes. In turn, this can demand different mathematical expressions to model landscape evolution as a function of time and or space. Landscape Evolution Models are mostly designed to facilitate the combination of different landscape-wide laws in a plug-and-play way and many frameworks are being developed in this aim. However, most current frameworks cannot capture important landscape processes such as lake dynamics and full sediment tracing because they are optimized for speed and handle fluxes separately. Several processes require information from more than the immediate neighboring cells within a time step and demand an integrated knowledge from the entire upstream trajectory. Lakes for example require knowledge of all upstream water and sediment fluxes to be filled. These can only be known if all the laws controlling those have been processed. Tackling these situation with a grid logic requires substantial amount of numerical refactoring from existing models.&lt;/p&gt;&lt;p&gt;We present an alternative method to tackle landscape evolution modelling in heterogeneous landscapes with a framework inspired from Lagrangian and cellular automaton methods. Our framework only relies on the assumption that upstream nodes needs to be processed before the downstream ones, including lakes with outlets, in order to process all selected governing equations on a pixel-to-pixel basis. This way, we ensure that the true content of sediment and water fluxes can be known and tracked at any points. We first utilise graph theory to (i) find the most comprehensive path to reroute water through depressions and (ii) determine a generic multiple flow topological order (any node is processed after all potential upstream ones). Particles that register and track all fluxes simultaneously can then &quot;roll&quot; on the landscape and merge between each other while interacting with the grid.&lt;/p&gt;&lt;p&gt;This formulation makes possible a number of generic features. (i) The laws can be dynamically adapted to the environment (e.g. switching from single to multiple flow function of water content, adapting erodibility function of the sediment composition and quantity), (ii) Depressions can be explicitly managed, filled (or not) and separated from the rest of the landscape (e.g. sedimentation or evaporation in lakes) as a function function of inputted fluxes and parameters, (iii) full provenance, transport time, and deposition tracking as the particle can always keep in memory where the fluxes are from and in what proportions. In this contribution, we demonstrate the impact the importance of considering these additional elements in landscape evolution. In particular, lake dynamic can significantly impact the long-term signal propagation from source to sink.&lt;/p&gt;


Author(s):  
Michael Getzner

-National parks and other categories of protected areas are often assumed to enhance regional economic development due to park tourism. The current study attempts to estimate the impact of the Hohe Tauern national park (Austria) on tourism by exploring whether and to what extent the national park may have had an influence on tourism development. For most national park communities, the results suggest that the establishment of the national park had some impact by enforcing an already positive trend or by weakening or reversing a negative trend of tourism. However, breakpoint tests exhibit turning points up to several years after the establishment of the park, indicating that taking a national park as the basis for tourism development is a medium to long term development strategy. In the short term, the impact of a national park on tourism is not measurable. Tourism increased by 1 to 3% annually after the breakpoint, indicating that the establishment of a national park has to be incorporated into the tourism and development strategy of a region right from the start. The causal relationship between the establishment of the national park and tourism development may be weak, in particular in communities where the difference between the actual and the forecast numbers of overnight stays is small. Marketing national park tourism and building up a brand or distinctive label may therefore contribute to regional development particularly in the long term.Key words: Tourism, national park, protected area, time series, stationarity, breakpoint test, ARIMA.JEL classifications: R110, L830, C220.Parole chiave: Turismo, parco nazionale, area protetta, serie temporale, stazionarietŕ, test di breakpoint, ARIMA.


2019 ◽  
Vol 11 (20) ◽  
pp. 5839 ◽  
Author(s):  
Bouasone Sengsourivong ◽  
Masaru Ichihashi

This study estimates the impact of irrigation on household sticky rice productivity in Lao People’s Democratic Republic (Lao PDR) by applying propensity score matching (PSM) and the difference-in-differences (DID) method. This paper utilizes panel data from the Lao Expenditure and Consumption Survey (LECS) from 2003 to 2013. The results show that the average sales value and total production of sticky rice for irrigated households is greater than those for non-irrigated households by around 36 to 38% per season. Moreover, irrigated households experience improved sticky rice productivity of approximately 2.44 tons per hectare, per season, compared to non-irrigated households. In particular, compared to households with access to irrigation in one period of the surveys, households with access to irrigation in two periods of the surveys have nearly double the sticky rice productivity. Therefore, long-term access to irrigation is more effective for sticky rice productivity. However, we cannot find any evidence to support the impact of irrigation on household consumption. Some policy implications that can be derived from this research are that farmers should be intensively promoted to make the most use of irrigation, development of irrigation system is highly needed, and to ensure effectiveness of irrigation utilization local farmer involvement in monitoring procedure of irrigation is necessary.


2017 ◽  
Vol 21 ◽  
pp. 352-357 ◽  
Author(s):  
S. Sowmya ◽  
P.S. Meenu ◽  
R. Asha Latha ◽  
Devendra Narain Singh

Over the years, the field of geotechnical engineering focused on physical, chemical and mechanical aspects of the geomaterials. However, recent developments in environmental geotechnics have highlighted the impact of biological processes on geo-materials and their performance. Also, the present day geotechnical problems favour biological interventions to develop eco-friendly and sustainable technology. In view of this, the present study is a preliminary investigation on the impact of microbial loading on fine-grained soils. In addition, a protocol has been developed to establish ‘bio-geo interface’ between bacteria and the geo-material. However, long term studies are demanded in this direction for in-depth understanding of the mechanism for development of prospective application.


2012 ◽  
Vol 538-541 ◽  
pp. 2887-2891
Author(s):  
Yu Qian ◽  
Xiao Jun Xiang ◽  
Jun Li Yang

To reduce the miss distance of flight test missile, the midcourse guidance law is studied in this paper. The nonlinear projectile dynamic model is developed at first, and then designed the midcourse guidance law with the impact point prediction information. The guidance law was designed using the difference between predicting impact point and target point. To improve the guidance law’s performance, this research inducted the predicted impact point’s velocity information and integral term into guidance law command. At the end, the simulation was developed. The results of simulation show that the guidance law designed in this study is successful and it can satisfy the test missile’s flight mission requirements.


2019 ◽  
Vol 160 (5) ◽  
pp. 186-190
Author(s):  
Bernadett Borda ◽  
Attila Nemes ◽  
Csaba Lengyel ◽  
Tamás Várkonyi ◽  
Ferenc Rárosi ◽  
...  

Abstract: Introduction: Increase of liver function is one of the most common complications after kidney transplantation due to the use of immunosuppressive therapy and hyperlipidemia in addition to hepatitis C virus (HCV) infection. Method: Following the selection criteria (n = 59), the study is based on applied immunosuppressive therapy, baseline data of patients, further correlation between HCV and liver function deterioration. Patients were subjected to fasting laboratory examination to monitor serum electrolytes, uric acid and albumin levels. We looked at the effects of immunosuppressive therapy on the lipids (TG, TC, HDL, LDL) and liver enzymes (GOT, GPT, ALP, GGT). The analysis of the relationship between lipids and liver enzymes was also included in our study. Results: The data basics were not significantly different between the tacrolimus and the cyclosporine groups. In the laboratory results, Mg levels were significantly different between the two groups (p = 0.044). The impact of HCV on the liver function was significantly different on GGT (p = 0.008). We examed the lipids and liver function level between the tacrolimus and the patients receiving cyclosporine-based immunosuppression and the total cholesterol (p = 0.005) and GOT (p = 0.05) were significantly different between the two groups. Hyperlipidemia was associated with 26% of patients taking tacrolimus-based immunosuppression, and 89% of those receiving cyclosporine; the difference was significant (p = 0.002). Regarding the effect of hyperlipidemia on liver enzymes, ALP (p = 0.006) and GGT (p = 0.0001) were significantly higher. Conclusion: Increases in hepatic enzymes, ALT and GGT indicate the damage to hepatocytes. Beside the increase of liver function, which is the main risk factor in hepatitis on HCV soil, the applied immunosuppressive therapy and hyperlipidemia lead to degradation of allograft function and long-term graft loss. Orv hetil. 2019; 160(5): 186–190.


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