Proteobacteria is a major phylum of Gram-negative bacteria. They include a wide variety of pathogenic genera, such as Escherichia, Vibrio, Yersinia and many others. Others include many of the bacteria responsible for nitrogen fixation. Carl Woese established this grouping in 1987, calling it informally the "purple bacteria and their relatives"; because of the great diversity of forms found in this group, it was named after Proteus, a Greek god of the sea capable of assuming many different shapes and is not named after the Proteobacteria genus Proteus. Some Alphaproteobacteria can grow at low levels of nutrients and have unusual morphology such as stalks and buds. Others include agriculturally important bacteria capable of inducing nitrogen fixation in symbiosis with plants; the type order is the Caulobacterales. The mitochondria of eukaryotes are thought to be descendants of an alphaproteobacterium; the Betaproteobacteria are metabolically diverse and contain chemolithoautotrophs and generalist heterotrophs.

The type order is the Burkholderiales, comprising an enormous range of metabolic diversity, including opportunistic pathogens. The Gammaproteobacteria are the largest class in terms of species with validly published names; the type order is the Pseudomonadales, which include the genera Pseudomonas and the nitrogen-fixing Azotobacter. The Deltaproteobacteria include bacteria that are predators on other bacteria and are important contributors to the anaerobic side of the sulfur cycle; the type order is the Myxococcales, which includes organisms with self-organising abilities such as Myxococcus spp. The Epsilonproteobacteria are slender, Gram-negative rods that are helical or curved; the type order is the Campylobacterales, which includes important food pathogens such as Campylobacter spp. The Zetaproteobacteria are iron-oxidizing neutrophilic chemolithoautotrophs, distributed worldwide in estuaries and marine habitats; the type order is the Mariprofundales. The Hydrogenophilalia are obligate include heterotrophs and autotrophs.

The type order is the Hydrogenophilales. The Acidithiobacillia contain only sulfur and uranium-oxidising autotrophs; the type order is the Acidithiobacillales, which includes economically important organisms used in the mining industry such as Acidithiobacillus spp. The Oligoflexia are filamentous aerobes; the type order is the Oligoflexales. All "Proteobacteria" are Gram-negative, with an outer membrane composed of lipopolysaccharides. Many move about using flagella; the latter include the myxobacteria, an order of bacteria that can aggregate to form multicellular fruiting bodies. A wide variety in the types of metabolism exists. Most members are facultatively or obligately anaerobic, chemolithoautotrophic, heterotrophic, but numerous exceptions occur. A variety of genera, which are not related to each other, convert energy from light through photosynthesis. "Proteobacteria" are associated with the imbalance of microbiota of the lower reproductive tract of women. These species are associated with inflammation.

The group is defined in terms of ribosomal RNA sequences. The "Proteobacteria" are divided into nine classes with validly published names, referred to by the Greek letters alpha through zeta, the Acidithiobacillia, Hydrogenophilalia, Oligoflexia; these were regarded as subclasses of the phylum, but they are now treated as classes. These classes are monophyletic; the genus Acidithiobacillus, part of the Gammaproteobacteria until it was transferred to class Acidithiobacillia in 2013, was regarded as paraphyletic to the Betaproteobacteria according to multigenome alignment studies. In 2017, the Betaproteobacteria was subject to major revisions and the class Hydrogenophilalia was created to contain the order HydrogenophilalesProteobacterial classes with validly published names include some prominent genera: e.g.: Alphaproteobacteria: Brucella, Agrobacterium, Rickettsia, etc. Betaproteobacteria: Bordetella, Neisseria, etc. Gammaproteobacteria: Escherichia, Salmonella, Buchnera, Vibrio, etc. Deltaproteobacteria: Desulfovibrio, Bdellovibrio, etc.

Epsilonproteobacteria: Helicobacter, Wolinella, etc. Zetaproteobacteria: Mariprofundus, Ghiorsea Oligoflexia: Oligoflexus. Acidithiobacillia: Acidithiobacillus thiooxidans, Thermithiobacillus tepidarius Hydrogenophilalia: Hydrogenophilus thermoluteolus, Tepidiphilus margaritifer Transformation, a process in which genetic material passes from bacterium to another, has been reported in at least 30 species of "Proteobacteria" distributed in the classes alpha, beta and epsilon; the best-studied "Proteobacteria" with respect to natural genetic transformation are the medically important human pathogens Neisseria gonorrhoeae, Haemophilus influenzae and Helicobacter pylori. Natural genetic transformation is a sexual process involving DNA transfer from one bacterial cell to another through the intervening medium and the integration of the donor sequence into the recipient genome. In pathogenic "Proteobacteria", transformation appears to serve as a DNA repair process that protects the pathogen's DNA from attack by their host's phagocytic defenses that employ oxidative free radicals.

Proteobacteria information from Palaeos. Proteobacteria. – J. P. Euzéby: List of Prokaryotic names with Standing in Nomenclature

Wisconsin's 6th congressional district

Wisconsin's 6th congressional district is a congressional district of the United States House of Representatives in eastern Wisconsin. Located in the rural communities surrounding Madison and Green Bay, it includes a small portion of far northern Milwaukee County around River Hills. The district is represented by Glenn Grothman who came to office in January 2015; the 6th district has a long history of farming livestock in rural areas, is a major producer of both milk and grains. In the 2016 presidential election, the district voted 55% for Donald Trump and 38% for Hillary Clinton. Wisconsin's 6th congressional district came into existence in 1863 following the federal census of 1860; the first elected representative from the district was Walter D. McIndoe of Wausau; the district comprised the counties of the northern and western parts of the state. Following subsequent congressional reapportionment after each decennial census, the district's boundaries shifted eastward; the reapportionment of Congressional districts following the federal census of 1860 gave Wisconsin three additional members in the House of Representatives.

Members elected from the newly created 4th, 5th and 6th districts were chosen in the midterm elections of 1862 and took their seats in the lower house as part of the 38th United States Congress. The 6th District included the counties of Adams, Bad Ax, Burnett, Chippewa, Douglas, Eau Claire, Juneau, La Crosse, La Pointe, Monroe, Pierce, Portage, St. Croix and Wood. Areas of east central Wisconsin, which make up much of the 6th district today, were part of the newly created 5th district. Following the 1870 census Wisconsin gained two seats in the House of Representatives; the new 6th District included many counties in northeast Wisconsin. It included the counties of Brown, Door, Green Lake, Outagamie, Waupaca and Winnebago. Representative Philetus Sawyer of Oshkosh had been elected to Congress from Wisconsin's 5th District since 1865, was elected from the newly configured 6th District, he served the state as a member of the U. S. Senate; the federal census of 1880 showed further population growth in Wisconsin and the state gained a 9th Congressional seat.

Reapportionment of the state moved the 6th District to a more central location within the state, though the representatives elected from the district came from the communities along the shores of Lake Winnebago throughout the decade. The 6th District now included the counties of Adams, Green Lake, Outagamie and Winnebago. Following the census of 1890 Wisconsin gained a 10th Congressional seat; the 6th District shifted eastward to a configuration that resembled that of today's linear east to west shape with a population of 187,001. The state population was enumerated at 1,686,880; the 6th District included the counties of Calumet, Fond du Lac, Green Lake, Marquette and Winnebago. The state's population reached 2,069,042 according to the 1900 federal census and Wisconsin gained an additional seat in the House of Representatives; this was the peak of Wisconsin's Congressional representation and the state maintained 11 members of the House of Representatives until the opening of the 73rd United States Congress in 1933.

The 6th District shifted southward and included the counties of Dodge, Fond du Lac, Ozaukee and Washington. The counties in the vicinity of Lake Winnebago became part of the 8th District; the population of the counties making up the 6th District totaled 184,517. The 1910 census tabulated a population of 2,333,860 citizens for Wisconsin and the 1920 census saw the state's population grow to 2,632,670; as a result of this growth, the state retained its 11 seats in the House of Representatives throughout the 1910s and 1920s. Prior to congressional elections in 1912, the 6th District was reconfigured in manner closer to that of the 1893 apportionment; the district included the counties of Calument, Fond du Lac, Green Lake, Manitowoc and Winnebago. All 11 districts continued in the same configurations until the elections of 1932; the 6th district grew from 201,637 to 214,206 between the two enumerations. Wisconsin lost a congressional seat following the census of 1930; the 6th District now included Calumet, Fond du Lac, Sheboygan and Winnebago counties.

According to the 1950 census, the population of the district was 315,666. This southeastern shift of the district remained in effect for 30 years, ending with the 1962 elections; the state held on to all 10 of its Congressional seats following the 1960 census. As a result of changing population patterns, the districts were reapportioned. Green Lake County was added to the existing counties of the 6th District, which were Calumet, Fond du Lac, Sheboygan and Winnebago; this slight western shift gave the district a population of 391,743. It was during this era, that the Republican Party's domination of the district was broken. Democrat John Abner Race, represented the district from 1965 to 1967. Other than this brief interruption, a Republican has been sent to Washington, D. C. in every election since 1938. The state of Wisconsin gained 465,318 residents for a total of 4,418,683 according to the 1970 census; because this was a lower increase than other areas of the country, the state lost a seat in the House of Representatives, requiring the state's districts to be reapportioned.

The 6th District now extended farther west than at any time other since its original configuration in 1860. It now included all or portions of Adams, Fond du Lac, Green Lake, Manitowoc, Monroe

Pierre-Henri de Valenciennes

Pierre-Henri de Valenciennes was a French painter, influential in elevating the status of open-air painting. Valenciennes worked in Rome from 1778 to 1782, where he made a number of landscape studies directly from nature, sometimes painting the same set of trees or house at different times of day, he theorized on this idea in his 1800 treatise Reflections and Advice to a Student on Painting, Particularly on Landscape, developing a concept of a "landscape portrait" in which the artist paints a landscape directly while looking upon it, taking care to capture its particular details. Painting outside allowed Valenciennes to capture the fleeting changes of a landscape due to light and weather, he was a proponent of artists painting the same view at multiple times of day. Although he spoke of this as a type of painting of interest to "amateurs", as distinguished from the higher art of the academies, he found it of great interest, of his own works the surviving landscape portraits have been the most noted by commentators.

He in particular urged artists to capture the distinctive details of a scene's architecture, agriculture, so on, in order to give the landscape a sense of belonging to a specific place. Among his students were Jean-Victor Bertin, Achille Etna Michallon, Louis Étienne Watelet, Louis-François Lejeune and the first French panorama painter Pierre Prévost. Born in the city of Toulouse, he is buried there in the Père Lachaise Cemetery. Media related to Pierre-Henri de Valenciennes at Wikimedia Commons