scholarly journals Impacts of sunspot number and Geomagnetic aa-index on climate of Wet Zone West Africa during solar cycles 22–24

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Esther A. Hanson ◽  
Francisca N. Okeke
Keyword(s):  
Time Series ◽  
Regression Analysis ◽  
West Africa ◽  
Magnetic Activity ◽  
Solar Cycles ◽  
Activity Data ◽  
Solar Magnetic Activity ◽  
The Impact ◽  
Aa Index ◽  
Wet Zone

AbstractUsing the facilities at Heliophysics Science Division of NASA Goddard Space Flight Center, Greenbelt, MD, USA, we attempted to investigate the impact of solar magnetic activities on the climate of Wet Zone West Africa. The solar activity data namely, Sunspot Number (SSN) was obtained from the Royal Observatory of Belgium, Brussels; and Geomagnetic aa-index was obtained from World Data Center, Kyoto, Japan. Surface Air Temperature (SAT) and Rainfall data [for Port Harcourt in Nigeria and Abidjan in Cote D’Ivoire] were obtained from the HadCRUT-4 project of Climate Research Unit of University of East Anglia, United Kingdom. Firstly, we carried out Time Series Analysis of SSN and Geomagnetic aa-index spanning from 1950 to 2016. Secondly, we performed Regression Analysis on both solar activity data and climate variables to estimate the impact of solar magnetic activity on the Wet Zone West African climate. The Time Series Analysis showed that SSN variation was in-phase with Geomagnetic aa-index in all the solar cycles studied. Thus, Geomagnetic aa-index can be used as a proxy for studying solar magnetic activities. Performance of Regression Analysis showed that SSN regressed on SAT and Rainfall amounted to an average of 0.49 and 0.02% respectively throughout Solar Cycles 22–24. Furthermore, a regression of Geomagnetic aa-index on SAT and Rainfall yielded an average of 0.145 and 0.125% respectively. Our models showed that the variability of SAT and Rainfall in Wet Zone West Africa during Solar Cycles 22–24 are far less than 1%. Hence, the influence of SSN and Geomagnetic aa-index on SAT and Rainfall is less than 1%; and could cause ‘very small’ effect. These weak impacts are proofs that the variability of SAT and Rainfall were most probably not effected by SSN and Geomagnetic aa-index. Consequently, the variability of SAT and Rainfall in Wet Zone West Africa could not be attributed to SSN and Geomagnetic aa-index. We therefore, attempt to conclude that climate variability in Wet Zone West Africa is most probably not driven by solar magnetic activity, but could be attributed to anthropogenic activities.

scholarly journals Trends in floods in West Africa: analysis based on 11 catchments in the region

2015 ◽  
Vol 19 (11) ◽  
pp. 4707-4719 ◽  
Author(s):  
B. N. Nka ◽  
L. Oudin ◽  
H. Karambiri ◽  
J. E. Paturel ◽  
P. Ribstein
Keyword(s):  
Time Series ◽  
West Africa ◽  
Vegetation Indices ◽  
Contingency Tables ◽  
Flood Frequency ◽  
Trend Test ◽  
African Countries ◽  
Rainfall Index ◽  
Flood Magnitude ◽  
The Impact

Abstract. After the drought of the 1970s in West Africa, the variability in rainfall and land use changes mostly affected flow, and recently flooding has been said to be an increasingly common occurrence throughout the whole of West Africa. These changes have raised many questions about the impact of climate change on the flood regimes in West African countries. This paper investigates whether floods are becoming more frequent or more severe and to what extent climate patterns have been responsible for these changes. We analyzed the trends in the floods occurring in 11 catchments within West Africa's main climate zones. The methodology includes two methods for sampling flood events, namely the AM (annual maximum) method and the POT (peak over threshold), and two perspectives of analysis are presented: long-term analysis based on two long flood time series and a regional perspective involving 11 catchments with shorter series. The Mann–Kendall trend test and the Pettitt break test were used to detect nonstationarities in the time series. The trends detected in flood time series were compared to the rainfall index trends and vegetation indices using contingency tables in order to identify the main driver of change in flood magnitude and flood frequency. The relation between the flood index and the physiographic index was evaluated through a success criterion and the Cramer criterion calculated from the contingency tables. The results show the existence of trends in flood magnitude and flood frequency time series, with two main patterns. Sahelian floods show increasing flood trends and one Sudanian. catchment presents decreasing flood trends. For the overall catchments studied, trends in the maximum 5-day consecutive rainfall index (R5d) show good coherence with trends in flood, while the trends in normalized difference vegetation indices (NDVIs) do not show a significant agreement with flood trends, meaning that this index has possibly no impact on the behavior of floods in the region.

scholarly journals The impact of changing cigarette smoking habits and smoke-free legislation on orofacial cleft incidence in the United Kingdom: Evidence from two time-series studies

PLoS ONE ◽  
2021 ◽  
Vol 16 (11) ◽  
pp. e0259820
Author(s):  
Matthew Fell ◽  
Craig Russell ◽  
Jibby Medina ◽  
Toby Gillgrass ◽  
Shaheel Chummun ◽  
...  
Keyword(s):  
Time Series ◽  
Regression Analysis ◽  
United Kingdom ◽  
Northern Ireland ◽  
Cigarette Smoking ◽  
Smoking Prevalence ◽  
Orofacial Cleft ◽  
Individual Level ◽  
The United Kingdom ◽  
The Impact

Background Both active and passive cigarette smoking have previously been associated with orofacial cleft aetiology. We aimed to analyse the impact of declining active smoking prevalence and the implementation of smoke-free legislation on the incidence of children born with a cleft lip and/or palate within the United Kingdom. Methods and findings We conducted regression analysis using national administrative data in the United Kingdom between 2000–2018. The main outcome measure was orofacial cleft incidence, reported annually for England, Wales and Northern Ireland and separately for Scotland. First, we conducted an ecological study with longitudinal time-series analysis using smoking prevalence data for females over 16 years of age. Second, we used a natural experiment design with interrupted time-series analysis to assess the impact of smoke-free legislation. Over the study period, the annual incidence of orofacial cleft per 10,000 live births ranged from 14.2–16.2 in England, Wales and Northern Ireland and 13.4–18.8 in Scotland. The proportion of active smokers amongst females in the United Kingdom declined by 37% during the study period. Adjusted regression analysis did not show a correlation between the proportion of active smokers and orofacial cleft incidence in either dataset, although we were unable to exclude a modest effect of the magnitude seen in individual-level observational studies. The data in England, Wales and Northern Ireland suggested an 8% reduction in orofacial cleft incidence (RR 0.92, 95%CI 0.85 to 0.99; P = 0.024) following the implementation of smoke-free legislation. In Scotland, there was weak evidence for an increase in orofacial cleft incidence following smoke-free legislation (RR 1.16, 95%CI 0.94 to 1.44; P = 0.173). Conclusions These two ecological studies offer a novel insight into the influence of smoking in orofacial cleft aetiology, adding to the evidence base from individual-level studies. Our results suggest that smoke-free legislation may have reduced orofacial cleft incidence in England, Wales and Northern Ireland.

The Pied Piper of Crime in America: An Analysis of the Presidents’ and Public’s Agenda on Crime

2002 ◽  
Vol 13 (2) ◽  
pp. 139-155 ◽  
Author(s):  
Willard M. Oliver
Keyword(s):  
Time Series ◽  
Regression Analysis ◽  
Public Opinion ◽  
Presidential Rhetoric ◽  
Policy Area ◽  
Time Series Regression ◽  
Public Response ◽  
The Public ◽  
State Of The Union ◽  
The Impact

The theory of presidential influence over public opinion is used to predict the impact of presidential rhetoric on crime over the public’s concern for crime being “the most important problem facing the nation.” It is hypothesized that the more attention presidents give to the policy area of crime in the their State of the Union Addresses, the more concerned the public becomes with crime. Utilizing a time-series regression analysis of data collected from a content analysis of presidents’ State of the Union addresses on the Gallup Poll’s Most Important Problem series from 1946 to 1996, the analysis demonstrates that presidential mention of crime seems to elicit a public response, thus influencing public opinion of crime with a decay effect of approximately 1 year.

scholarly journals Educational intervention to optimise serum immunoglobulin test use in Irish primary care: an interrupted time series with segmented regression analysis

2019 ◽  
Vol 70 (691) ◽  
pp. e146-e154
Author(s):  
Sharon L Cadogan ◽  
John P Browne ◽  
Colin P Bradley ◽  
Anthony P Fitzgerald ◽  
Mary R Cahill
Keyword(s):  
Primary Care ◽  
Time Series ◽  
Regression Analysis ◽  
Laboratory Data ◽  
Interrupted Time Series ◽  
Serum Immunoglobulin ◽  
Segmented Regression ◽  
Segmented Regression Analysis ◽  
The Impact ◽  
Test Ordering

BackgroundImplementation science experts recommend that theory-based strategies, developed in collaboration with healthcare professionals, have greater chance of success.AimThis study evaluated the impact of a theory-based strategy for optimising the use of serum immunoglobulin testing in primary care.Design and settingAn interrupted time series with segmented regression analysis in the Cork–Kerry region, Ireland. An intervention was devised comprising a guideline and educational messages-based strategy targeting previously identified GP concerns relevant to testing for serum immunoglobulins.MethodInterrupted time series with segmented regression analysis was conducted to evaluate the intervention, using routine laboratory data from January 2012 to October 2016. Data were organised into fortnightly segments (96 time points pre-intervention and 26 post-intervention) and analysed using incidence rate ratios with their corresponding 95% confidence intervals.ResultsIn the most parsimonious model, the change in trend before and after the introduction of the intervention was statistically significant. In the 1-year period following the implementation of the strategy, test orders were falling at a rate of 0.42% per fortnight (P<0.001), with an absolute reduction of 0.59% per fortnight, corresponding to a reduction of 14.5% over the 12-month study period.ConclusionThe authors’ tailored guideline combined with educational messages reduced serum immunoglobulin test ordering in primary care over a 1-year period. Given the rarity of the conditions for which the test is utilised and the fact that the researchers had only population-level data, further investigation is required to examine the clinical implications of this change in test-ordering patterns.

scholarly journals Trends in West African floods: a comparative analysis with rainfall and vegetation indices

2015 ◽  
Vol 12 (5) ◽  
pp. 5083-5121 ◽  
Author(s):  
B. N. Nka ◽  
L. Oudin ◽  
H. Karambiri ◽  
J. E. Paturel ◽  
P. Ribstein
Keyword(s):  
Time Series ◽  
West Africa ◽  
Vegetation Indices ◽  
Contingency Tables ◽  
Flood Frequency ◽  
West African ◽  
Trend Test ◽  
Rainfall Index ◽  
Flood Magnitude ◽  
The Impact

Abstract. After the drought of the 1970s in West Africa, the variability of rainfall and land use changes affected mostly flow, and recently flooding has been said to be an increasingly common occurrence throughout the whole of West Africa. These changes raised many questions about the impact of climate change on the flood regimes in West African countries. This paper investigates whether floods are becoming more frequent or more severe, and to what extent climate patterns have been responsible for these changes. We analyzed the trends in the floods occurring in 14 catchments within West Africa's main climate zone. The methodology includes two methods for sampling flood events, namely the AM (annual maximum) method and the POT (peak over threshold), and two perspectives of analysis are presented: long-term analysis based on two long flood time series, and a regional perspective involving 14 catchments with shorter series. The Mann–Kendall trend test and the Pettitt break test were used to assess time series stationarity. The trends detected in flood time series were compared to the rainfall index trends and vegetation indices using contingency tables, in order to identify the main driver of change in flood magnitude and flood frequency. The relation between the flood index and the physiographic index was evaluated through a success criterion and the Cramer criterion calculated from the contingency tables. The results point out the existence of trends in flood magnitude and flood frequency time series with two main patterns. Sahelian floods show increasing flood trends and some Sudanian catchments present decreasing flood trends. For the overall catchments studied, the maximum 5 day consecutive rainfall index (Rx5d) seems to follow the flood trend, while the NDVI indices do not show a significant link with the flood trends, meaning that this index has no impact in the behavior of floods in the region.

The Impact of Union-Management Cooperation on Productivity and Employment

ILR Review ◽  
1983 ◽  
Vol 36 (3) ◽  
pp. 415-430 ◽  
Author(s):  
Michael Schuster
Keyword(s):  
Time Series ◽  
Regression Analysis ◽  
Qualitative Data ◽  
Time Series Data ◽  
Series Data ◽  
Time Intervals ◽  
Manufacturing Plants ◽  
Cooperative Program ◽  
The Impact ◽  
Employment Data

This study examines the effects of union-management cooperative programs on productivity and employment. The author collected productivity and employment data for each of nine manufacturing plants at monthly time intervals over a period of four to five years—from two years before to at least two years after the introduction of the cooperative program. Regression analysis of these time-series data is supplemented by qualitative data from personal interviews and relevant records. The results show that after introduction of the cooperative programs, productivity increased in six of the eight firms in which it could be measured and employment remained stable in eight of the nine firms.

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