variation index
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Author(s):  
Jeronimo Esteve-Perez ◽  
Antonio Garcia-Sanchez

The continuous growth of the cruise industry has brought with it a series of threats. Among them is the management of the seasonality of cruise activity in order to address its negative effects. This study examines the monthly cruise passenger movement distribution among a group of harbors located in the northeast sector of the Atlantic Ocean and the Baltic Sea with the aim of determining the existence of seasonality patterns in cruise traffic and their relationship between different regions. A database of cruise passenger movements during the period from 2007 to 2019 among 24 harbors forms the backbone of the empirical analysis. First, the seasonal variation index of each harbor was calculated to determine the seasonality pattern. Second, a cluster analysis was performed to classify harbors into clusters with analogous seasonality patterns. The results reveal that seasonality of cruise activity in a consolidated region is explained by own factors of the region, but also by an induced seasonality imported from neighboring cruise regions.


2021 ◽  
Vol 9 (11) ◽  
pp. 1295
Author(s):  
Jerónimo Esteve-Pérez ◽  
José Enrique Gutiérrez-Romero ◽  
Carlos Mascaraque-Ramírez

The Iberian Peninsula represents the second European producer and the eighth world producer of vehicles in 2020. The pandemic of SARS-Cov2 introduced severe challenges for the worldwide population and for the industrial production and supply chains. The car carrier shipping sector has not been studied in depth in the Maritime Transportation and Port Logistics literature. This research pays special attention to the performance of this traffic in the Iberian Peninsula in the pre-pandemic era and under COVID-19 pandemic conditions, in which seven ports with car-carrier ship traffic in the Iberian Peninsula are analyzed. First, a dynamic portfolio analysis about how the COVID-19 pandemic affected the evolution of competitive positions of Iberian Peninsula ports is performed. Second, studies of the seasonality patterns of vehicle movements in ports of the Iberian Peninsula were carried out using time series of the periods from 2012 to 2019 and from 2012 to 2020. The Seasonal Variation Index (SVI) was employed to determine the seasonality of vehicle traffic in the periods considered and analyses were performed independently for both embarking and disembarking traffic. Important conclusions are revealed, e.g., during a year of COVID-19, the seven ports had decreased vehicle movements for disembarking traffic and only one port increased the traffic for embarking traffic. Furthermore, COVID-19 introduced important changes in the seasonality patterns of vehicle movements during the first months of the pandemic.


Author(s):  
Xiaolu Zhang ◽  
Linglei Zhang ◽  
Min Chen ◽  
Dian Li ◽  
Min Peng ◽  
...  

Abstract Runoff processes are the basis for maintaining the safety of river ecosystems. The Yarlung Zangbo River (YZR) faces changes in flow regimes due to the impacts of human activities and climate change#which may threaten its fragile ecosystem. In this study#a new comprehensive system for evaluating runoff variation was constructed to investigate the degree of runoff alternation in the YZR. Based on the data from the primary hydrological stations in the YZR from 1956 to 2000#the assessment indicators of runoff variation were selected by considering the flow#sediment#and water temperature processes. Furthermore#a comprehensive evaluation system for runoff variation was constructed via multiple hydrological analysis methods and vague sets. The results showed that the variation index of the YZR from 2010 to 2013 was 0.15–0.20 compared with the flow regimes of the YZR before 2000#which were within a reasonable range#indicating that the comprehensive runoff conditions of the YZR were not greatly disturbed by human activities such as reservoir construction and river regulation during this period. These results provide a tool for evaluating the runoff change in the YZR and new references for researching runoff variation in other similar watersheds.


2021 ◽  
Vol 24 (2) ◽  
pp. 6-12
Author(s):  
Yakime de Brito Adrião ◽  
Mário Reis Álvares da Silva ◽  
Alexandre de Araújo ◽  
Soraia Arruda ◽  
Paola Hoff Alves

Introduction: Calculation of the Tacrolimus variation index by using the MLVI (Medication Level Variability Index) is set in pediatric liver transplant patients, and it is useful in controlling treatment adherence by associating MLVI values > 2.5 to acute graft liver rejection. Purpose: To verify the association between MLVI values and rejection in adult liver transplant patients. Methods: A retrospective cohort study including liver transplant patients over 18 years of age from December 2012 to December 2017 using orally tacrolimus. For MLVI calculation, tacrolimus serum level outpatient samples were used after 1 year of transplantation. Results: A total of 125 patients were transplanted, of which 86 met criteria for inclusion in the study. The most frequent reason for transplantation was C virus infection (55.8%, n = 48). Rejection was identified in 18.6% of patients (n = 16). The mean MLVI among rejection and nonrejection patients was 2.5 and 2.1 respectively (RR = 0.95, CI: 0.4-2.1, p = 0.57). The frequency of non-immunological complications was 56.2% (n = 9) in patients with rejection versus 62.8% (n = 44) in patients without rejection, most of them with recurrence of virus C (56,8%, n = 25). Conclusion: Although the mean value of MLVI was higher in patients with rejection, our data showed no statistical difference between both groups, which differs from previous studies in pediatric patients. A higher number of nonimmune complications were observed in patients without rejection. The findings suggest that new MLVI cutoffs should be explored in the adult population.


2021 ◽  
Vol 13 (16) ◽  
pp. 3317
Author(s):  
Sourabhi Debnath ◽  
Manoranjan Paul ◽  
D. M. Motiur Rahaman ◽  
Tanmoy Debnath ◽  
Lihong Zheng ◽  
...  

The efficiency of a vineyard management system is directly related to the effective management of nutritional disorders, which significantly downgrades vine growth, crop yield and wine quality. To detect nutritional disorders, we successfully extracted a wide range of features using hyperspectral (HS) images to identify healthy and individual nutrient deficiencies of grapevine leaves. Features such as mean reflectance, mean first derivative reflectance, variation index, mean spectral ratio, normalised difference vegetation index (NDVI) and standard deviation (SD) were employed at various stages in the ultraviolet (UV), visible (VIS) and near-infrared (N.I.R.) regions for our experiment. Leaves were examined visually in the laboratory and grouped as either healthy (i.e. control) or unhealthy. Then, the features of the leaves were extracted from these two groups. In a second experiment, features of individual nutrient-deficient leaves (e.g., N, K and Mg) were also analysed and compared with those of control leaves. Furthermore, a customised support vector machine (SVM) was used to demonstrate that these features can be utilised with a high degree of effectiveness to identify unhealthy samples and not only to distinguish from control and nutrient deficient but also to identify individual nutrient defects. Therefore, the proposed work corroborated that HS imaging has excellent potential to analyse features based on healthiness and individual nutrient deficiencies of grapevine leaves.


Author(s):  
Valentina Mazzi ◽  
Giuseppe De Nisco ◽  
Ayla Hoogendoorn ◽  
Karol Calò ◽  
Claudio Chiastra ◽  
...  

AbstractAlthough unphysiological wall shear stress (WSS) has become the consensus hemodynamic mechanism for coronary atherosclerosis, the complex biomechanical stimulus affecting atherosclerosis evolution is still undetermined. This has motivated the interest on the contraction/expansion action exerted by WSS on the endothelium, obtained through the WSS topological skeleton analysis. This study tests the ability of this WSS feature, alone or combined with WSS magnitude, to predict coronary wall thickness (WT) longitudinal changes. Nine coronary arteries of hypercholesterolemic minipigs underwent imaging with local WT measurement at three time points: baseline (T1), after 5.6 ± 0.9 (T2), and 7.6 ± 2.5 (T3) months. Individualized computational hemodynamic simulations were performed at T1 and T2. The variability of the WSS contraction/expansion action along the cardiac cycle was quantified using the WSS topological shear variation index (TSVI). Alone or combined, high TSVI and low WSS significantly co-localized with high WT at the same time points and were significant predictors of thickening at later time points. TSVI and WSS magnitude values in a physiological range appeared to play an atheroprotective role. Both the variability of the WSS contraction/expansion action and WSS magnitude, accounting for different hemodynamic effects on the endothelium, (1) are linked to WT changes and (2) concur to identify WSS features leading to coronary atherosclerosis.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Polycarp Uchechukwu Ori ◽  
Ayo Adebowale ◽  
Chukwuma David Umeokonkwo ◽  
Ugochukwu Osigwe ◽  
Muhammad Shakir Balogun

Abstract Background Measles accounts for high morbidity and mortality in children, especially in developing countries. In 2017, about 11,190 measles cases were recorded in Nigeria, including Bauchi State. The aim of this study was to describe the trend and burden of measles in Bauchi State, Nigeria. Method We analyzed secondary data of measles cases extracted from the Measles Surveillance data system in Bauchi State from January 2013 to June 2018. The variables extracted included age, sex, doses of vaccination, case location and outcome. Data were analyzed using descriptive statistics, logistic regression, and multiplicative time series model (α = 0.05). Results A total of 4935 suspected measles cases with an average annual incidence rate of 15.3 per 100,000 population and 57 deaths (Case Fatality Rate, CFR: 1.15%) were reported. Among the reported cases, 294 (6%;) were laboratory-confirmed, while clinically compatible and epi-linked cases were 402 (8%) and 3879 (70%), respectively. Of the 4935 measles cases, 2576 (52%) were males, 440 (9%) were under 1 year of age, and 3289 (67%) were between 1 and 4 years. The average annual incidence rate among the 1–4 year age-group was 70.3 per 100,000 population. The incidence rate was lowest in 2018 with 2.1 per 100,000 and highest in 2015 with 26.2 per 100,000 population. The measles cases variation index per quarter was highest in quarter 1 (198.86), followed by quarter 2 (62.21) and least in quarter 4 (10.37) of every year. Only 889 (18%) of the measles cases received at least one dose of measles vaccine, 2701 (54.7%) had no history of measles vaccination while 1346 (27.3%) had unknown vaccination status. The fatality of measles in Bauchi State were significantly associated with being under 5 years (AOR = 5.58; 95%CI: 2.19–14.22) and not having at least a dose of MCV (OR = 7.14; 95%CI: 3.70–14.29). Conclusion Measles burden remains high in Bauchi State despite a decrease in its incidence over the study years. Most of the cases occurred in the first quarter of every year. Improved routine measles surveillance for prompt case management could reduce the burden of the disease in Bauchi State.


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