scholarly journals First Report of Xylella fastidiosa on Catharanthus roseus in Brazil

Plant Disease ◽  
1998 ◽  
Vol 82 (6) ◽  
pp. 712-712 ◽  
Author(s):  
B. Ueno ◽  
C. K. Funada ◽  
M. A. Yorinori ◽  
R. P. Leite
Keyword(s):  
Catharanthus Roseus ◽  
Xylella Fastidiosa ◽  
Xylem Sap ◽  
Glass Slide ◽  
Bacterial Cells ◽  
First Report ◽  
Vein Clearing ◽  
The Media ◽  
Agar Media ◽  
The U.S

In 1998, plants of periwinkle (Catharanthus roseus L.) showing small leaves, short internodes, and dieback symptoms were observed in a garden at the Instituto Agronomico do Parana (IAPAR), Londrina, PR, Brazil. Stems of these plants were cut into short sections and the sap extracted from the tissue by squeezing with pliers. The sap was blotted onto a glass slide and examined for the presence of bacteria by light microscopy (×400). Microscopy observations revealed the presence of a large number of slender, rod-shaped bacterial cells. The bacteria present in the stems of periwinkle were isolated on buffered cysteine-yeast extract (BCYE) and periwinkle wilt (PW) agar media. Stems were disinfected in 70% alcohol and cut into short sections, and the sap extracted as described above. The sap was blotted directly onto the media and the plates were incubated at 28°C. Typical colonies of Xylella fastidiosa were observed 10 days after isolation on both media. Indirect immunofluorescence tests with antibody specific to X. fastidiosa and anti-IgG conjugated with tetrametylrhodamine isothiocyanate (TRITC) were carried out with xylem sap of periwinkle stem and the isolated bacteria. In both cases, immunofluorescence tests were positive for X. fastidiosa. These results confirm that periwinkle plants were infected with X. fastidiosa. This is the first report of the association of X. fastidiosa with periwinkle plants in Brazil. However, the symptoms observed for the X. fastidiosa-infected periwinkle plants differed from those described previously in the U.S. (1): those symptoms consisted of marginal chlorosis and occasional vein clearing of leaves and wilting of the plants. Reference: (1) R. E. McCoy et al. Plant Dis. Rep. 62:1022, 1978.

scholarly journals The DinJ/RelE Toxin-Antitoxin System Suppresses Bacterial Proliferation and Virulence of Xylella fastidiosa in Grapevine

2017 ◽  
Vol 107 (4) ◽  
pp. 388-394 ◽  
Author(s):  
Lindsey P. Burbank ◽  
Drake C. Stenger
Keyword(s):  
Xylella Fastidiosa ◽  
Xylem Sap ◽  
Bacterial Pathogen ◽  
Growth Conditions ◽  
Plant Colonization ◽  
Insect Vector ◽  
Bacterial Cells ◽  
Knockout Mutant ◽  
Bacterial Proliferation ◽  
Systemic Spread

Xylella fastidiosa, the causal agent of Pierce’s disease of grapes, is a slow-growing, xylem-limited, bacterial pathogen. Disease progression is characterized by systemic spread of the bacterium through xylem vessel networks, causing leaf-scorching symptoms, senescence, and vine decline. It appears to be advantageous to this pathogen to avoid excessive blockage of xylem vessels, because living bacterial cells are generally found in plant tissue with low bacterial cell density and minimal scorching symptoms. The DinJ/RelE toxin-antitoxin system is characterized here for a role in controlling bacterial proliferation and population size during plant colonization. The DinJ/RelE locus is transcribed from two separate promoters, allowing for coexpression of antitoxin DinJ with endoribonuclease toxin RelE, in addition to independent expression of RelE. The ratio of antitoxin/toxin expressed is dependent on bacterial growth conditions, with lower amounts of antitoxin present under conditions designed to mimic grapevine xylem sap. A knockout mutant of DinJ/RelE exhibits a hypervirulent phenotype, with higher bacterial populations and increased symptom development and plant decline. It is likely that DinJ/RelE acts to prevent excessive population growth, contributing to the ability of the pathogen to spread systemically without completely blocking the xylem vessels and increasing probability of acquisition by the insect vector.

Variations in Surface Textures of Quartz Sand using Electron Microscopy

1970 ◽  
Vol 28 ◽  
pp. 494-495
Author(s):  
Eugene J. Amaral
Keyword(s):  
Electron Microscopy ◽  
Glass Industry ◽  
Glass Slide ◽  
Distilled Water ◽  
Early Paleozoic ◽  
Secondary Effects ◽  
Surface Textures ◽  
High Silica ◽  
Sand Deposit ◽  
The U.S

Examination of sand grain surfaces from early Paleozoic sandstones by electron microscopy reveals a variety of secondary effects caused by rock-forming processes after final deposition of the sand. Detailed studies were conducted on both coarse (≥0.71mm) and fine (=0.25mm) fractions of St. Peter Sandstone, a widespread sand deposit underlying much of the U.S. Central Interior and used in the glass industry because of its remarkably high silica purity.The very friable sandstone was disaggregated and sieved to obtain the two size fractions, and then cleaned by boiling in HCl to remove any iron impurities and rinsed in distilled water. The sand grains were then partially embedded by sprinkling them onto a glass slide coated with a thin tacky layer of latex. Direct platinum shadowed carbon replicas were made of the exposed sand grain surfaces, and were separated by dissolution of the silica in HF acid.

Fake It “Till You Make It”: Debunking Fake News in a Post-Truth America

2019 ◽  
Vol 8 (1) ◽  
pp. 114-133
Keyword(s):  
Social Media ◽  
First Amendment ◽  
Presidential Election ◽  
Political Discourse ◽  
Cutting Edge ◽  
American People ◽  
Fake News ◽  
News Sources ◽  
The Media ◽  
The U.S

Since the 2016 U.S. presidential election, attacks on the media have been relentless. “Fake news” has become a household term, and repeated attempts to break the trust between reporters and the American people have threatened the validity of the First Amendment to the U.S. Constitution. In this article, the authors trace the development of fake news and its impact on contemporary political discourse. They also outline cutting-edge pedagogies designed to assist students in critically evaluating the veracity of various news sources and social media sites.

scholarly journals Europe Abhors Donald Trump: The Opinion on the 2020 U.S. Presidential Elections and Their Candidates in the European Newspapers

2021 ◽  
pp. 000276422110055
Author(s):  
Marçal Sintes-Olivella ◽  
Pere Franch ◽  
Elena Yeste-Piquer ◽  
Klaus Zilles
Keyword(s):  
Qualitative Methodology ◽  
Election Campaign ◽  
Donald Trump ◽  
Presidential Debates ◽  
White House ◽  
The United Kingdom ◽  
European Public ◽  
The Media ◽  
The Common ◽  
The U.S

What is the opinion held by the European press on the U.S. election campaign and the candidates running for president? What are the predominant issues that attract the attention of European print media? Does Europe detest Donald Trump? The objective of the present study is to analyze the perception European commentators had of the 2020 race for the White House. The media, the audience, and European governments were captivated more than ever before by how the U.S. election campaign unfolded, fixing their gaze on the contest between Donald Trump and Joe Biden. Through a combined quantitative and qualitative methodology, a combination of content analysis and the application of framing theory (hitherto scarcely applied to opinion pieces), our research centers on exploring the views, opinions, and analyses published in eight leading newspapers from four European countries (France, Germany, Spain, and the United Kingdom) as expressed in their editorials and opinion articles. This study observes how the televised presidential debates were commented on, interpreted, and assessed by commentators from the eight newspapers we selected. The goal was to identify the common issues and frames that affected European public opinion on the U.S. presidential campaign and the aspirants to the White House.

Party Messaging in the U.S. House of Representatives

2021 ◽  
pp. 106591292110297
Author(s):  
Tyler Hughes ◽  
Gregory Koger
Keyword(s):  
House Of Representatives ◽  
Voting Behavior ◽  
Policy Debate ◽  
Strategic Decisions ◽  
The Public ◽  
Substantive Content ◽  
Legislative Agenda ◽  
The Media ◽  
Party Members ◽  
The U.S

Both Congressional parties compete to promote their own reputations while damaging the opposition party’s brand. This behavior affects both policy-making agendas and the party members’ communications with the media and constituents. While there has been ample study of partisan influence on legislative agenda-setting and roll call voting behavior, much less is known about the parties’ efforts to shape the public debate. This paper analyzes two strategic decisions of parties: the timing of collective efforts to influence the public policy debate and the substantive content of these “party messaging” events. These dynamics are analyzed using a unique dataset of 50,195 one-minute speeches delivered on the floor of the U.S. House of Representatives from 1989 to 2016. We find a pattern of strategic matching—both parties are more likely to engage in concurrent messaging efforts, often on the same issue.

scholarly journals How Does a COVID mRNA vaccine really work?

Ubiquity ◽  
2021 ◽  
Vol 2021 (July) ◽  
pp. 1-12
Author(s):  
Walter Tichy
Keyword(s):  
Infectious Disease ◽  
Immune System ◽  
Messenger Rna ◽  
Spike Protein ◽  
Foreign Protein ◽  
The Real ◽  
Virus Rna ◽  
German Company ◽  
The Media ◽  
The U.S

The most potent weapon against COVID-19 is a vaccine based on messenger RNA (mRNA). The first of these vaccines authorized for use was developed by the German company BioNTech in cooperation with Pfizer, closely followed by the (U.S.-produced) Moderna vaccine. These vaccines send a piece of mRNA into cells of a host. The mRNA instructs the cells to produce masses of the same spike protein that also occurs on the shell of the real coronavirus. The immune system responds by learning to destroy anything showing that protein: if the real virus arrives, the immune system will attack it immediately. This much has been reported widely by the media. But important questions remain. How is mRNA actually synthesized as a transcription of the spike-producing segment of the virus' RNA? How is the selection and replication done? How does mRNA enter a host cell, and how long will it stay there? Will it produce the spike protein forever? Is it perhaps dangerous? And the biggest question of all: How does the immune system record the structure of the foreign protein, how does it recognize the invader, and how is the immune response cranked up? To answer these questions, we bring you a conversation between Ubiquity editor Walter Tichy and his daughter Dr. Evelyn Tichy, an infectious disease expert.

scholarly journals Corporate Governance of Artificial Intelligence in the Public Interest

Information ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 275
Author(s):  
Peter Cihon ◽  
Jonas Schuett ◽  
Seth D. Baum
Keyword(s):  
Artificial Intelligence ◽  
Corporate Governance ◽  
Law Enforcement ◽  
Nonprofit Organizations ◽  
Public Interest ◽  
Department Of Defense ◽  
The Public ◽  
Wide Range ◽  
The Media ◽  
The U.S

Corporations play a major role in artificial intelligence (AI) research, development, and deployment, with profound consequences for society. This paper surveys opportunities to improve how corporations govern their AI activities so as to better advance the public interest. The paper focuses on the roles of and opportunities for a wide range of actors inside the corporation—managers, workers, and investors—and outside the corporation—corporate partners and competitors, industry consortia, nonprofit organizations, the public, the media, and governments. Whereas prior work on multistakeholder AI governance has proposed dedicated institutions to bring together diverse actors and stakeholders, this paper explores the opportunities they have even in the absence of dedicated multistakeholder institutions. The paper illustrates these opportunities with many cases, including the participation of Google in the U.S. Department of Defense Project Maven; the publication of potentially harmful AI research by OpenAI, with input from the Partnership on AI; and the sale of facial recognition technology to law enforcement by corporations including Amazon, IBM, and Microsoft. These and other cases demonstrate the wide range of mechanisms to advance AI corporate governance in the public interest, especially when diverse actors work together.

scholarly journals First Report of Apricot vein clearing-associated virus (AVCaV) infecting Prunus domestica revealed by High-Throughput Sequencing in Morocco

Plant Disease ◽  
2020 ◽  
Author(s):  
Rachid Tahzima ◽  
Radouane Qessaoui ◽  
Yoika Foucart ◽  
Sebastian Massart ◽  
Kris De Jonghe
Keyword(s):  
Fruit Trees ◽  
Plant Viruses ◽  
Amino Acid Sequences ◽  
Stone Fruit ◽  
Replicase Gene ◽  
Prunus Domestica ◽  
Prunus Species ◽  
First Report ◽  
Vein Clearing ◽  
The Impact

Plum (Prunus domestica L., Rosaceae) trees, like many stone fruit trees, are known to be infected by numerous plant viruses, predominantly as consequence of their clonal mode of propagation and perennial cultivation (Jelkmann and Eastwell, 2011). Apricot vein clearing-associated virus (AVCaV) is a member of the genus Prunevirus in the family Betaflexiviridae. AVCaV was first reported in Italy infecting apricot (P. armeniaca L.) associated with foliar vein clearing symptoms (Elbeaino et al. 2014). It has also been detected in various Prunus species, like plum, Japanese plum (P. salicina L.), sour cherry (P. cerasus L.), and Japanese apricot (P. mume L.), apricot and peach (P. persica L.) sourced from Asian and European countries (Marais et al. 2015), as well as in the ornamental Myrobolan plum (P. cerasifera L.) in Australia (Kinoti et al. 2017). In 2018, during the vegetative season, a survey was carried out in two different apricot and plum orchards in the southern region of Agdez (Agadir, Morocco) where stone fruit trees are grown. Five branches with leaves were sampled from three apricot and three plum trees of unknown cultivars, all asymptomatic. Total RNA was extracted from 100 mg plant tissue (leaves and cambial scrapping) using RNeasy Plant Mini Kit (QIAGEN, Hilden, Germany) and separate samples (one per species) were used for library preparation (NEBNext Ultra RNA library kit; New England BioLabs, MA, USA), and sequencing (Illumina NextSeq v2, totRNA sequencing) at Admera Health (New Jersey, USA). All generated reads (6,756,881) from the plum sample were quality filtered and submitted to the VirusDetect pipeline (Zheng et al., 2017). The plum cDNA library, a total of 20 viral contigs (68-1928 bp) mapped to several AVCaV accessions in GenBank. A reference mapping (CLC Genomics Workbench 12, Qiagen, Denmark) was conducted against all four available AVCaV full genomes (KM507062-63, KY132099 and HG008921), revealing 100% coverage of the full sequence (8358 nt) with 97-98 % nucleotide (nt) identities (BLASTn). Analysis of the derived sequences allowed to identify the location of the four predicted ORFs i.e. (ORF1: 6066 nt/2,021 aa), (ORF2: 1383 nt/460 aa), (ORF3: 666 nt/221 aa) and (ORF4: 420 nt/139 aa), previously described for the AVCaV genome (Elbeaino et al. 2014). The amino acid sequences of the encoded proteins of AVCaV isolate from Morocco also shared 97-98% identities with the corresponding sequences of complete genome AVCaV isolates in GenBank. To confirm the detection of AVCaV in the three plum samples, specific RT-PCR primers (VC37657s: 5’-CCATAGCCACCCTTTTTCAA-3’ / VC28239a: 5’-GTCGTCAAGGGTCCAGTGAT-3’) (Elbeaino et al. 2014) were used and the expected 330 bp fragment from the replicase gene was amplified in all three samples and subsequently sequenced (MT980794-96). Sanger sequences were 100% identical to corresponding HTS derived sequence. This is the first report of AVCaV infecting plum in Africa. The incidence of AVCaV in Moroccan Prunus species is unknown. Plum trees from the surveyed orchards were also confirmed to be co-infected with little cherry virus 1 (LChV-1) using HTS. Further investigation is required to determine the impact of AVCaV on these asymptomatic plum trees and other stone fruits species.

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