The transmission modes of taijiquan

2020 ◽  
pp. 45-53
Author(s):  
Pierrick Porchet
Keyword(s):  
Transmission Modes

Prevalence and genetic diversity of viruses associated with rugose wood complex in Greek vineyards

Plant Disease ◽  
2021 ◽  
Author(s):  
Chrysoula Orfanidou ◽  
Kalliopi Moraki ◽  
Polina Panailidou ◽  
Leonidas Lotos ◽  
Asimina T Katsiani ◽  
...  
Keyword(s):  
Phylogenetic Trees ◽  
First Record ◽  
Grapevine Virus ◽  
Multiple Introductions ◽  
Worldwide Distribution ◽  
Grapevine Virus A ◽  
Transmission Modes ◽  
Virus Incidence ◽  
Grapevine Virus B ◽  
Rupestris Stem Pitting

Rugose wood is one of the most important disease syndromes of grapevine and it has been associated with at least three viruses: grapevine rupestris stem pitting associated virus (GRSPaV), grapevine virus A (GVA) and grapevine virus B (GVB). All three viruses show a worldwide distribution pattern, and their genetic composition has been the focus of extensive research over the past years. Despite their first record in Greece almost 20 years ago, there is a lack of knowledge on the distribution and genetic variability of their populations in Greek vineyards. In this context, we investigated the distribution of GRSPaV, GVA and GVB in rootstocks, self-rooted and grafted grapevine cultivars, originating from different geographic regions that are representing important viticultural areas of Greece. Three new RT-PCR assays were developed for the reliable detection of GRSPaV, GVA and GVB. Our results indicated that GVA is the most prevalent in Greek vineyards, followed by GRSPaV and GVB. However, virus incidence differed among self-rooted and grafted grapevine cultivars or rootstocks tested. Selected isolates from each virus were further molecularly characterized to determine their phylogenetic relationships. All three viruses exhibited high nucleotide diversity, which was depicted in the constructed phylogenetic trees. Isolates from Greece were placed in various phylogroups, reinforcing the scenario of multiple introductions of GVA, GVB and GRSPaV in Greece and highlighting the effect of different transmission modes in the evolutionary course of the three viruses.

scholarly journals The effect of life-history and mode of inheritance on neutral genetic variability

2001 ◽  
Vol 77 (2) ◽  
pp. 153-166 ◽  
Author(s):  
BRIAN CHARLESWORTH
Keyword(s):  
Sequence Variation ◽  
Adult Mortality ◽  
Structured Populations ◽  
Human Populations ◽  
Effective Population ◽  
Transmission Modes ◽  
Population Sizes ◽  
Age Structured ◽  
Infinite Sites Model ◽  
Site Diversity

Formulae for the effective population sizes of autosomal, X-linked, Y-linked and maternally transmitted loci in age-structured populations are developed. The approximations used here predict both asymptotic rates of increase in probabilities of identity, and equilibrium levels of neutral nucleotide site diversity under the infinite-sites model. The applications of the results to the interpretation of data on DNA sequence variation in Drosophila, plant, and human populations are discussed. It is concluded that sex differences in demographic parameters such as adult mortality rates generally have small effects on the relative effective population sizes of loci with different modes of inheritance, whereas differences between the sexes in variance in reproductive success can have major effects, either increasing or reducing the effective population size for X-linked loci relative to autosomal or Y-linked loci. These effects need to be accounted for when trying to understand data on patterns of sequence variation for genes with different transmission modes.

QUANTIZATION OF ENTROPY SPECTRA OF BLACK HOLES

2013 ◽  
Vol 22 (02) ◽  
pp. 1330001 ◽  
Author(s):  
YONGJOON KWON ◽  
SOONKEON NAM
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Correspondence Principle ◽  
Scattering Problem ◽  
Classical System ◽  
Quasinormal Modes ◽  
Entropy Spectrum ◽  
Total Transmission ◽  
Transmission Modes ◽  
Characteristic Modes

From the quasinormal modes (QNM) of black holes, we obtain the quantizations of the entropy and horizon area of black holes via Bohr–Sommerfeld quantization, based on Bohr's correspondence principle. For this, we identify the appropriate action variable of the classical system corresponding to a black hole. By considering the BTZ black holes in topologically massive gravity as well as Einstein gravity, it is found that the spectra of not the horizon areas but the entropies of black holes are equally spaced. We also propose that other characteristic modes of black holes, which are non-QNM or holographic QNM, can be used in quantization of entropy spectra just like QNM. From these modes, it is found that only the entropy spectrum of the warped AdS3 black hole is equally spaced as well. Furthermore, by considering a scattering problem in a black hole, we propose that the total transmission modes and total reflection modes of black holes can be regarded as characteristic modes of black holes and result in the equally spaced entropy of the Kerr and Reissner–Nordström black holes. Finally, we conclude that there is a universal behavior that the entropy spectra of various black holes are equally spaced.

Comparative analysis of the performance of selective and group repeat transmission modes in a transport protocol

2017 ◽  
Vol 78 (2) ◽  
pp. 247-260 ◽  
Author(s):  
V. V. Kokshenev ◽  
P. A. Mikheev ◽  
S. P. Sushchenko
Keyword(s):  
Comparative Analysis ◽  
Transport Protocol ◽  
Transmission Modes

scholarly journals Disease transmission by cannibalism: rare event or common occurrence?

2007 ◽  
Vol 274 (1614) ◽  
pp. 1205-1210 ◽  
Author(s):  
Volker H.W Rudolf ◽  
Janis Antonovics
Keyword(s):  
Disease Transmission ◽  
Rare Event ◽  
Disease Spread ◽  
Necessary Condition ◽  
Transmission Route ◽  
Review Of The Literature ◽  
Common Occurrence ◽  
Endemic Diseases ◽  
Pathogen Dynamics ◽  
Transmission Modes

Cannibalism has been documented as a possible disease transmission route in several species, including humans. However, the dynamics resulting from this type of disease transmission are not well understood. Using a theoretical model, we explore how cannibalism (i.e. killing and consumption of dead conspecifics) and intraspecific necrophagy (i.e. consumption of dead conspecifics) affect host–pathogen dynamics. We show that group cannibalism, i.e. shared consumption of victims, is a necessary condition for disease spread by cannibalism in the absence of alternative transmission modes. Thus, endemic diseases transmitted predominantly by cannibalism are likely to be rare, except in social organisms that share conspecific prey. These results are consistent with a review of the literature showing that diseases transmitted by cannibalism are infrequent in animals, even though both cannibalism and trophic transmission are very common.

scholarly journals Minimal transmission in an influenza A (H3N2) human challenge-transmission model within a controlled exposure environment

2019 ◽  
Author(s):  
Jonathan S. Nguyen-Van-Tam ◽  
Ben Killingley ◽  
Joanne Enstone ◽  
Michael Hewitt ◽  
Jovan Pantelic ◽  
...  
Keyword(s):  
Attack Rate ◽  
Influenza A ◽  
Transmission Model ◽  
Epidemiological Methods ◽  
Large Droplet ◽  
Transmitted Infection ◽  
Modes Of Transmission ◽  
Transmission Modes ◽  
Building Ventilation ◽  
Transmission Studies

AbstractUncertainty about the importance of influenza transmission by airborne droplet nuclei generates controversy for infection control. Human challenge-transmission studies have been supported as the most promising approach to fill this knowledge gap. Healthy, seronegative volunteer ‘Donors’ (n=52) were randomly selected for intranasal challenge with influenza A/Wisconsin/67/2005 (H3N2). ‘Recipients’ randomized to Intervention (IR, n=40) or Control (CR, n=35) groups were exposed to Donors for four days. IRs wore face shields and hand sanitized frequently to limit large droplet and contact transmission. One transmitted infection was confirmed by serology in a CR, yielding a secondary attack rate of 2.9% among CR, 0% in IR (p=0.47 for group difference), and 1.3% overall, significantly less than 16% (p<0.001) expected based on a proof-of-concept study secondary attack rate and considering that there were twice as many Donors and days of exposure. The main difference between these studies was mechanical building ventilation in the follow-on study, suggesting a possible role for aerosols.Author summaryUnderstanding the relative importance of influenza modes of transmission informs strategic use of preventive measures to reduce influenza risk in high-risk settings such as hospitals and is important for pandemic preparedness. Given the increasing evidence from epidemiological modelling, exhaled viral aerosol, and aerobiological survival studies supporting a role for airborne transmission and the potential benefit of respirators (and other precautions designed to prevent inhalation of aerosols) versus surgical masks (mainly effective for reducing exposure to large droplets) to protect healthcare workers, more studies are needed to evaluate the extent of risk posed airborne versus contact and large droplet spray transmission modes. New human challenge-transmission studies should be carefully designed to overcome limitations encountered in the current study. The low secondary attack rate reported herein also suggests that the current challenge-transmission model may no longer be a more promising approach to resolving questions about transmission modes than community-based studies employing environmental monitoring and newer, state-of-the-art deep sequencing-based molecular epidemiological methods.

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