range restriction
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2021 ◽  
Vol 66 (6) ◽  
pp. 50-56
Author(s):  
I. Kuznetsova

Purpose: comparative epidemiological analysis of cancer incidence rates among PA Mayak workers hired at different calendar periods. Material and Methods: The cohort of PA Mayak workers hired at reactors, radiochemical, plutonium, water preparing and repair plants in 1948-1982 was selected for analysis of solid cancer (except lung, liver and bone) incidence. The cohort was divided into two subcohorts 1948-1958 and 1959-1982 years of hire. Regression models of relative risk included the description of background rates and excess radiation risk was used. Results: The radiation relative risk per 1 Gy was (ERR/Gy: 0.11; 95 % CI: 0.02; 0.21) in the subcohort of workers hired in 1948–1958 and was close to the estimates from previous studies for the whole cohort. In the subcohort of workers hired in 1959–1982 the point estimate of ERR/Gy was 3 times higher than in the subcohort 1948–1958 years of hire, but it was not statistically significant in the whole dose range. Restriction of doses up to 2 Gy allowed to get significant estimate of ERR/Gy (0.45; 95 % CI: 0.04; 0.95), which 4 times higher the estimate in the first subcohort calculated with the same restriction (0.11; 95 % CI: -0.01; 0.25). All subcohorts differences were not statistically significant and we can say about point distinctions only.


2021 ◽  
Author(s):  
Alicia Franco-Martínez ◽  
Jesús M. Alvarado ◽  
Miguel A. Sorrel

A sample suffers range restriction (RR) when its variance is reduced comparing to its population variance and, in turn, it fails representing such population. If the RR occurs over the latent factor, not directly over the observed variable, the researcher deals with an indirect RR, common when using convenience samples. This work explores how this problem affects different outputs of the factor analysis: multivariate normality (MVN), estimation process, goodness-of-fit, recovery of factor loadings, and reliability. In doing so, a Monte Carlo study was conducted. Data were generated following the linear selective sampling model, simulating tests varying their sample size (N = 200 and 500 cases), test size (J = 6, 12, 18, 24 items), loading size (L = .50, .70, and .90) and restriction size (from R = 1, .90, .80, and so on till .10 selection ratio). Our results systematically suggest that an interaction between decreasing the loading size and increasing the restriction size affects the MVN assessment, obstructs the estimation process, and leads to an underestimation of the factor loadings and reliability. However, most of the MVN tests and most of the fit indices employed were nonsensitive to the RR problem. We provide some recommendations to applied researchers.


2021 ◽  
Vol 102 (9) ◽  
Author(s):  
Jermilia Charles ◽  
Chandra S. Tangudu ◽  
Daniel Nunez-Avellaneda ◽  
Aaron C. Brault ◽  
Bradley J. Blitvich

Most flaviviruses are transmitted horizontally between vertebrate hosts by haematophagous arthropods. Others exhibit host ranges restricted to vertebrates or arthropods. Vertebrate-specific flaviviruses are commonly referred to as no-known-vector (NKV) flaviviruses and can be separated into bat- and rodent-associated NKV flaviviruses. Rio Bravo virus (RBV) is one of eight recognized bat-associated NKV (B-NKV) flaviviruses. Studies designed to identify the genetic determinants that condition the host range restriction of B-NKV flaviviruses have never been performed. To investigate whether the host range restriction occurs at the level of attachment or entry, chimeric flaviviruses were created by inserting the pre-membrane and envelope protein genes of RBV into the genetic backbones of yellow fever virus (YFV) and Zika virus (ZIKV), two mosquito-borne flaviviruses associated with human disease. The chimeric viruses infected both vertebrate and mosquito cells. In vertebrate cells, all viruses produced similar mean peak titres, but the chimeric viruses grew more slowly than their parental viruses during early infection. In mosquito cells, the chimeric virus of YFV and RBV grew more slowly than YFV at early post-inoculation time points, but reached a similar mean peak titre. In contrast, the chimeric virus of ZIKV and RBV produced a mean peak titre that was approximately 10-fold lower than ZIKV. The chimeric virus of YFV and RBV produced an intermediate plaque phenotype, while the chimeric virus of ZIKV and RBV produced smaller plaques than both parental viruses. To conclude, we provide evidence that the structural glycoproteins of RBV permit entry into both mosquito and vertebrate cells, indicating that the host range restriction of B-NKV flaviviruses is mediated by a post-attachment/entry event.


Author(s):  
Matthew C. Le Feuvre ◽  
Tim Dempster ◽  
James J. Shelley ◽  
Aaron M. Davis ◽  
Stephen E. Swearer

2021 ◽  
Vol 9 (5) ◽  
pp. 939-942
Author(s):  
Neha Shukla ◽  
◽  
Chandrashekhar Kumar ◽  

Background: Trigger point on calf muscle is a common musculoskeletal condition it is usually felt as an intense pain when the concerned extremity is used to put on weight.The upper medial and upper lateral trigger points refer pain locally to the back of the knee causing slight end range restrictions. it is the most common musculoskeletal complaint presenting to physicaltherapy. Objective: Reduction of calf pain and to improve the end range of motion of the knee joint. Thus, helps in enhancing the functional activities. Methods: The study was done on one patient aiming to reduce calf pain and mild end range restriction of knee joint movements, we used dry needling technique for treatmentpurpose Result: We found reduction in the calf muscle pain and improvement in end range of movement of the knee joint after 2 sessions of dry needling. Case Representation: one patient came to us having pain on calf muscle, local tenderness and end range restriction of the knee joint and patient was having no history of trauma patient was undergoing for analgesic medication.


PLoS ONE ◽  
2021 ◽  
Vol 16 (5) ◽  
pp. e0249633
Author(s):  
Andrew J. Bladon ◽  
Paul F. Donald ◽  
Nigel J. Collar ◽  
Jarso Denge ◽  
Galgalo Dadacha ◽  
...  

Climate change is having profound effects on the distributions of species globally. Trait-based assessments predict that specialist and range-restricted species are among those most likely to be at risk of extinction from such changes. Understanding individual species’ responses to climate change is therefore critical for informing conservation planning. We use an established Species Distribution Modelling (SDM) protocol to describe the curious range-restriction of the globally threatened White-tailed Swallow (Hirundo megaensis) to a small area in southern Ethiopia. We find that, across a range of modelling approaches, the distribution of this species is well described by two climatic variables, maximum temperature and dry season precipitation. These same two variables have been previously found to limit the distribution of the unrelated but closely sympatric Ethiopian Bush-crow (Zavattariornis stresemanni). We project the future climatic suitability for both species under a range of climate scenarios and modelling approaches. Both species are at severe risk of extinction within the next half century, as the climate in 68–84% (for the swallow) and 90–100% (for the bush-crow) of their current ranges is predicted to become unsuitable. Intensive conservation measures, such as assisted migration and captive-breeding, may be the only options available to safeguard these two species. Their projected disappearance in the wild offers an opportunity to test the reliability of SDMs for predicting the fate of wild species. Monitoring future changes in the distribution and abundance of the bush-crow is particularly tractable because its nests are conspicuous and visible over large distances.


2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Wadii Hajji

The first theorem in this article provides the connection between Ehresmann semigroups and range prerestriction semigroups defined by the author. By this connection, we can redefine any Ehresmann semigroups by two unary operations and eight axioms. This connection leads us to a generalization of Ehresmann’s theorem for a range prerestriction categories; as special cases, we obtain Ehresmann’s theorems for range restriction categories and for inverse categories.


Author(s):  
Mert Demir

This article proposes the integration of electromagnetic weapons on a robot, design and construction of an electromagnetic armed robot, autonomous targeting of possible targets with the electromagnetic weapon, and the features a electromagnetic armed safety robot should have. Unlike traditional user-targeted field security robot approaches, the robot mentioned in this study detects potential threats in the task area with image processing and artificial intelligence techniques, so the user can accurately identify and autonomously target targets without the need for controlled targeting. Unlike today’s armed robots, an electromagnetic armed robot, which will be a new literature study, has been developed to create a reference path. An electromagnetic weapon that can be carried by a robot is produced and integrated into the robot and a new armed robot approach with electromagnetic weapon is introduced. Various methods are proposed considering the range restriction of electromagnetic weapons and possible targeting errors of the robot user. A control algorithm has been developed to have the most appropriate targeting under the dynamic constraints of the robot and user for target tracking. Prototyping and experiments show the ability of an autonomous security robot with an autonomous targeting system to troubleshoot user problems and targeting problems. In addition, various methods and recommendations are provided for the features that a electromagnetic armed security robot working in the field should have.


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