scholarly journals Impact of complete lock-down on total infection and death rates: A hierarchical cluster analysis

Author(s):  
Samit Ghosal ◽  
Rahul Bhattacharyya ◽  
Milan Majumder

AbstractIntroduction and AimsRetarding the spread of SARS-CoV-2 infection by preventive strategies is the first line of management. Several countries have declared a stringent lock-down in order to enforce social distancing and prevent the spread of infection. This analysis was conducted in an attempt to understand the impact of lock-down on infection and death rates over a period of time.Material and MethodsA validated database was used to generate data related to countries with declared lock-down. Simple regression analysis was conducted to assess the rate of change in infection and death rates. Subsequently, a k-means and hierarchical cluster analysis was done to identify the countries that performed similarly. Sweden and South Korea were included as counties without lock-down in a second-phase cluster analysis.ResultsThere was a significant 61% and 43% reduction in infection rates 1-week post lock-down in the overall and India cohorts, respectively, supporting its effectiveness. Countries with higher baseline infections and deaths fared poorly compared to those who declared lock-down early on. Sweden and South Korea fared equally well, as most lock-down countries stemmed the growth of infection and death.ConclusionLock-down has proven to be an effective strategy is slowing down the SARS-CoV-2 disease progression exponentially. However, lessons need to be learned from Sweden and South Korea on arresting the disease progression without imposing such stringent measures.

2017 ◽  
Vol 52 (1) ◽  
pp. 135-150 ◽  
Author(s):  
Sara Etz Mendonça ◽  
Elisa A. Merçon-Vargas ◽  
Ayse Payir ◽  
Jonathan R. H. Tudge

This study aimed to examine children’s expression of gratitude in Brazil, China, Guatemala, Russia, South Korea, Turkey, and the United States. Participants ( N = 2,265) consisted of 7- to 14-year-olds ( M = 10.56, SD = 2.09; 54.4% girls). Using hierarchical cluster analysis, we found four clusters of gratitude expression: (a) Russia and Turkey (moderate–high expression of connective, low concrete, and moderate verbal gratitude), (b) Brazil and the United States (low connective, higher rates of concrete, and moderate–high rates of verbal gratitude), (c) China and South Korea (higher rates of connective, lower concrete, and lower–moderate verbal gratitude), and (d) Guatemala (lower rates of concrete and connective gratitude, and higher rates of verbal gratitude). In addition, we found common trends in age-related differences for verbal and concrete gratitude among most societies. These findings support the argument for diligence in avoiding implicit generalizations based on research conducted mostly in Western Educated Industrialized Rich Democratic (WEIRD) societies.


2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Amani Taamalli ◽  
David Arráez Román ◽  
Ana María Gómez Caravaca ◽  
Mokhtar Zarrouk ◽  
Antonio Segura Carretero

The olive plant has been extensively studied for its nutritional value, whereas its leaves have been specifically recognized as a processing by-product. Leaves are considered by-products of olive farming, representing a significant material arriving to the olive mill. They have been considered for centuries as an important herbal remedy in Mediterranean countries. Their beneficial properties are generally attributed to the presence of a range of phytochemicals such as secoiridoids, triterpenes, lignans, and flavonoids. With the aim to study the impact of geographical location on the phenolic compounds, Olea europaea leaves were handpicked from the Tunisian cultivar “Chemlali” from nine regions in the north, center, and south of Tunisia. The ground leaves were then extracted with methanol : water 80% (v/v) and analyzed by using high-performance liquid chromatography coupled to electrospray time of flight and ion trap mass spectrometry analyzers. A total of 38 compounds could be identified. Their contents showed significant variation among samples from different regions. Hierarchical cluster analysis was applied to highlight similarities in the phytochemical composition observed between the samples of different regions.


2006 ◽  
Vol 27 ◽  
pp. 21-43 ◽  
Author(s):  
Douglas D. Roscoe ◽  
Shannon Jenkins ◽  
John Frendreis ◽  
Alan R. Gitelson

Explanations for election outcomes have commonly included incumbency and candidate quality. While these explanations have been successful, they do not wholly explain who wins or loses. To move beyond the concepts of incumbency and quality, a typology of candidates is developed based on their motivations for running. Hierarchical cluster analysis is employed to examine open-ended responses from state legislative candidates in nine states. The resulting typologies are found to be connected to influences on candidate emergence and perceptions of factors that influenced the election outcome. They also prove to be statistically significant predictors of election victory even when controlling for incumbency, quality, spending, and campaign professionalism. The findings should encourage others to move beyond conventional explanations of election out-comes.


Author(s):  
Milan Radojicic ◽  
Aleksandar Djokovic ◽  
Nikola Cvetkovic

Unpredictable and uncontrollable situations have happened throughout history. Inevitably, such situations have an impact on various spheres of life. The coronavirus disease 2019 has affected many of them, including sports. The ban on social gatherings has caused the cancellation of many sports competitions. This paper proposes a methodology based on hierarchical cluster analysis (HCA) that can be applied when a need occurs to end an interrupted tournament and the conditions for playing the remaining matches are far from ideal. The proposed methodology is based on how to conclude the season for Serie A, a top-division football league in Italy. The analysis showed that it is reasonable to play 14 instead of the 124 remaining matches of the 2019–2020 season to conclude the championship. The proposed methodology was tested on the past 10 seasons of the Serie A, and its effectiveness was confirmed. This novel approach can be used in any other sport where round-robin tournaments exist.


2010 ◽  
Vol 41 (2) ◽  
pp. 126-133 ◽  
Author(s):  
N. Kalamaras ◽  
H. Michalopoulou ◽  
H. R. Byun

In this study a method proposed by Byun & Wilhite, which estimates drought severity and duration using daily precipitation values, is applied to data from stations at different locations in Greece. Subsequently, a series of indices is calculated to facilitate the detection of drought events at these sites. The results provide insight into the trend of drought severity in the region. In addition, the seasonal distribution of days with moderate and severe drought is examined. Finally, the Hierarchical Cluster Analysis method is used to identify sites with similar drought features.


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