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Medium 9781780647128

18: An Experimental Approach to Understanding Grapevine Yellows Associated with Phytoplasma Infections

Compant, S.; Mathieu, F. CABI PDF

18

An Experimental Approach to Understanding Grapevine

Yellows Associated with

Phytoplasma Infections

G. Brader,1* S. Compant,1,2 H. Gangl3 and A. Sessitsch1

AIT Austrian Institute of Technology GmbH, Health and Environment

Department, Tulln an der Donau, Austria; 2LGC UMR 5503 (CNRS/

INPT/UPS), Département Bioprocédés et Systèmes Microbiens,

Université de Toulouse, Castanet-Tolosan, France; 3Bundesamt für

Weinbau, Eisenstadt, Austria

1

Introduction

Phytoplasmas are cell wall-less bacteria of the class Mollicutes with low G + C content and small genome sizes. They colonize the phloem of plants and are transmitted by phloem-sucking Hemiptera. Phytoplasmas are associated with more than 100 plant diseases worldwide. The symptoms of phytoplasma infections are phyllody/virescence, yellowing, witches’ broom formations, stunting and (lethal) declines and diebacks. They affect various domesticated plants, and can cause significant economic losses, particularly in high-value crops (Hogenhout et al., 2008; Bertaccini and Duduk, 2009). In 2001, a single outbreak of apple proliferation phytoplasma resulted in losses of more than €100 million in Italy and €25 million in Germany (Strauss, 2009). The treatment of most phytoplasma diseases is difficult and concentrates on the control of vectors transmitting the disease. Direct plant treatments with antibiotics are possible, but not desirable for sustainable agriculture and also very costly and often ineffective (Bertaccini and Duduk, 2009). The study of phytoplasma diseases is complicated by the difficulty of cultivating these organisms in vitro.

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Medium 9781623491376

5. Water: Shared Ownership

Porter, Charles R. Texas A&M University Press ePub

WATER: SHARED OWNERSHIP

States neighboring Texas claim ownership of their surface water and groundwater. The states share surface water, from major boundary rivers to hundreds of streams and creeks. The Red River and the Sabine River form part of our boundaries with Oklahoma, Arkansas, and Louisiana. Texas shares transboundary aquifers with New Mexico, and the Rio Grande springs from Colorado and New Mexico headwaters. In any dispute between states over surface water, the only court with jurisdiction is the United States Supreme Court.

OKLAHOMA, ARKANSAS, LOUISIANA, AND NEW MEXICO

To date there have been few disputes with our neighboring states other than some boundary disputes with Oklahoma as the Red River meanders—disputes concerning oil and gas reserve locations. The Sabine River between Texas and Louisiana is located in the wet area of the state in relation to rainfall, so the potential for disputes over water issues is lessened. However, the Sabine springs from headwaters in Texas, and any diversion of Sabine flow would certainly concern Louisiana, as any diversion of the Sabine on the Louisiana side would Texas. The Canadian River flows through the Texas Panhandle from New Mexico through a large part of Oklahoma. Any diversions by New Mexico and/or Texas concern Oklahoma. In the early twentieth century the Elephant Butte Reservoir on the Rio Grande caused quite a debate, but Texas and New Mexico came to agreement and the reservoir was built.

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Medium 9781603446938

Part 2 Creating the Perfect Setting

Rudolph A. Rosen Texas A&M University Press ePub

Here I was, head of an organization poised to raise well over $500,000 from the people filling the auditorium, yet I had only a conceptual image of what was to happen next. No one had ever seen it. There was no way to have seen it, because there was only one opportunity to do it, and now it was time. The president of the organization didn’t have a clue what was going to happen, and he was starting to fidget. He would soon become upset. The invited guests were enjoying themselves—so far. Waitstaff were serving drinks, which was expected, of course.

I could hear the small talk starting. People were beginning to wonder what was going on. This event could be an absolute smash hit—at least in theory. We were assembled in an auditorium. Nothing was onstage. The nothingness was purposefully obvious. Looking onto the stage was like looking into a massive black hole. Nothing was in the seating area. Nothing was in the aisles. Nothing was anywhere and everywhere. A few people sat in the auditorium’s seats, but mostly they stood in small groups in aisles and just waited in the emptiness.

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Medium 9781780646947

16: Biodiversity, Bioindicators and Biogeography of Freshwater Algae

Ansari, A.; Gill, S.S.; Abbas, Z.K. CABI PDF

16 

Biodiversity, Bioindicators and

Biogeography of Freshwater Algae

Martin T. Dokulil*

EX Research Institute Mondsee, Mondsee, Austria

Abstract

Biodiversity and the problems associated with it are outlined and then the focus turns to continental waters. Levels and factors affecting biodiversity are described and listed. Measures of diversity focus on species richness and the Shannon index using abundances and biovolumes. Spatial scales of measuring and monitoring of biodiversity are listed and explained.

Diversity of algae is then discussed in detail, including phytoplankton and algae on substrates, and a discussion of the paradox of the plankton and the ‘everything is everywhere’ hypothesis. The biogeographic distributions of algal groups are mentioned, with a particular focus on endemism, followed by a brief consideration of trophic interactions. Biodiversity of algae is described and evaluated from five case studies using long-term data on phytoplankton from three lakes, a length profile of plankton from the River Danube and epilithic algae from an artificial system. The results and findings are critically discussed with respect to advantages and drawbacks in using single indices. The use of algae and their diversity as biological indicators (biomarkers) in environmental assessments is finally outlined, followed by concluding remarks.

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Medium 9780253000804

6: The Arctic during the Cretaceous

Roland A. Gangloff Indiana University Press ePub

North America and the western Arctic as experienced by dinosaurs and their kin were much different places than today. Today we find the planet dominated by large continents with interiors that are relatively far removed from the ocean margins. The oceans are now at what is called a low stand, because significant amounts of water are locked up as ice caps at both poles. Oceans act as great moderators of temperature and moisture. They are conveyors of heat energy, transferring energy to the colder land masses during winters and acting as coolers when the continents heat up during the summer.1 The oceans act as reservoirs of moisture by recycling water to the continental surfaces as precipitation. The pattern of precipitation is directly linked to the flow of heat energy and to the patterns of high and low pressure. Temperature and precipitation directly control the distribution and types of vegetation that are available to terrestrial animals such as dinosaurs.

Alaska and the Western Interior Seaway

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