Acanthodii or acanthodians is an extinct paraphyletic class of teleostome fish, sharing features with both bony fish and cartilaginous fish. In form they resembled sharks, but their epidermis was covered with tiny rhomboid platelets like the scales of holosteans, they represent several independent phylogenetic branches of fishes leading to the still extant Chondrichthyes. The popular name "spiny sharks" is a partial misnomer for these early jawed fishes; the name was coined because they were superficially shark-shaped, with a streamlined body, paired fins, a upturned tail. Fossilized spines and scales are all that remains of these fishes in ancient sedimentary rocks. Although not sharks or cartilaginous fish, acanthodians did, in fact, have a cartilaginous skeleton, but their fins had a wide, bony base and were reinforced on their anterior margin with a dentine spine; the earliest acanthodians were marine, but during the Devonian, freshwater species became predominant. There are three orders recognized: Ischnacanthiformes and Acanthodiformes.
Climatiiforma had shoulder armor and many small sharp spines, Ischnacanthiforma with teeth fused to the jaw, the Acanthodiforma were filter feeders, with no teeth in the jaw, but long gill rakers. Overall, the acanthodians' jaws are presumed to have evolved from the first gill arch of some ancestral jawless fishes that had a gill skeleton made of pieces of jointed cartilage. Paraphyletic groupings are problematic, as one can not talk about their phylogenic relationships, their characteristic traits and literal extinction; the scales of Acanthodii have distinctive ornamentation peculiar to each order. Because of this, the scales are used in determining relative age of sedimentary rock; the scales are tiny, with a bulbous base, a neck, a flat or curved diamond-shaped crown. Despite being called "spiny sharks," acanthodians predate sharks. Scales that have been tentatively identified as belonging to acanthodians, or "shark-like fishes" have been found in various Ordovician strata, they are ambiguous, may belong to jawless fishes such as thelodonts.
The earliest unequivocal acanthodian fossils date from the beginning of the Silurian Period, some 50 million years before the first sharks appeared. The acanthodians colonized fresh waters, throve in the rivers and lakes during the Devonian and in the coal swamps of Carboniferous. By this time bony fishes were showing their potential to dominate the waters of the world, their competition proved too much for the spiny sharks, which died out in Permian times. Many palaeontologists considered the acanthodians close to the ancestors of the bony fishes. Although their interior skeletons were made of cartilage, a bonelike material had developed in the skins of these fishes, in the form of fitting scales; some scales were enlarged and formed a bony covering on top of the head and over the lower shoulder girdle. Others developed a bony flap over the gill openings analogous to the operculum in bony fishes. However, most of these characteristics are considered homologous characteristics derived from common placoderm ancestors, present in basal cartilaginous fish.
In a study of early jawed vertebrate relationships, Davis et al. found acanthodians to be split among the two major clades Osteichthyes and Chondrichthyes. The well-known acanthodian Acanthodes was placed within Osteichthyes, despite the presence of many chondrichthyan characteristics in its braincase. However, a newly described Silurian placoderm, which has jaw anatomy shared with bony fish and tetrapods, has led to revisions of this phylogeny: acanthodians were considered to be a paraphyletic assemblage leading to cartilaginous fish, while bony fish evolved from placoderm ancestors. Burrow et al. 2016 provides vindication by finding chondrichthyans to be nested among Acanthodii, most related to Doliodus and Tamiobatis. A 2017 study of Doliodus morphology points out that it appears to display a mosaic of shark and acanthodian features, making it a transitional fossil and further reinforcing this idea. Beneš, Prehistoric Animals and Plants, New York: Hamlyn, ISBN 978-0-600-30341-1 Janvier, Early vertebrates, Oxford: Clarendon Press, ISBN 978-0-19-854047-2 Long, John A.
The Rise of Fishes: 500 Million Years of Evolution, Baltimore: Johns Hopkins University Press, ISBN 978-0-8018-4992-3 Palmer, Douglas, ed. The Simon & Schuster Encyclopedia of Dinosaurs & Prehistoric Creatures. A Visual Who's Who of Prehistoric Life, New York: Simon & Schuster, ISBN 978-0-684-86411-2 Acanthodii taxonomy †Ischnacanthiformes taxonomy †Climatiiformes taxonomy †Acanthodiformes taxonomy "PALAEOZOIC FISH UK". Archived from the original on 2012-10-11. Acanthodopsis wardi
This article addresses US armed forces military computers and their use. Some of the earliest computers were military computers. Military requirements for portability and ruggedness led to some of the earliest transistorized computers, such as the 1959 AN/MYK-1, the 1960 M18 FADAC, the 1962 D-17B. Military requirements for a computer small enough to fit through a submarine's hatch led to the AN/UYK-1. A military computer is much more robust than an industrial computer enclosure. Most electronics will be protected with a layer of conformal coating. There will be more structure inside to support the components, the plug-in cards will be individually supported and secured to assure they do not pop out of their sockets, the processor and heat sink will be secured, memory will be glued into their sockets, so forth; this is to assure nothing moves during the shock events. There are several differentiators between military computers and typical office or consumer computers: Cost Intended environment Long term availability Architecture Feature setCost – Military computers are much more expensive than office/consumer computers.
Consumer computers from manufacturers such as Dell are manufactured in high quantities which leads to lower costs due to economy of scale. Military programs, on the other hand, can require small numbers of systems leading to higher costs. Military computers will also be constructed of more robust materials with more internal structure, more cooling fans, a more robust power supply, so forth. Intended Environment – An office or consumer computer is intended for use in a controlled shirt-sleeve environment with moderate temperatures and humidity and minimal dust. A military computer can be designed to operate in adverse environments with extremes of temperature such as -20C to +65C operating, 5% to 95% humidity levels, high dust loading in the air as well as other insults to the hardware, they may be required to operate in high salt environments such as on a ship or designed for high shock and vibration such as on a ship or submarine. Military computers may be intended for installation on aircraft in which case they need to be crash worthy and able to operate at high altitudes if in unpressurized aircraft.
The same computer may be required to operate in Afghanistan as well as in Alaska with no change in the design. Long Term Availability – Military programs last years and identical replacement hardware may be required over the life of the program. Consumer computers are driven by the latest and greatest to realize the highest possible performance, such as required to play games; the motherboard in a consumer grade computer may have an availability measured in months instead of years or decades. In a consumer level computer, over the lifetime of the product availability, it is not unheard of for all the components such as the motherboard, drives, BIOS, video board, etc. to be different from computer to computer. That is not acceptable in a military computer for which supporting documents have been created and systems tested and approved. Architecture – There are many types of computer architecture; the most common that people know of is the PC as created by IBM. Many military computer systems are built around alternative plug-in bus structures such as VMEbus or Compact PCI.
A military computer may not provide for plug-in cards and be in a dedicated form factor for a specific application such as installation on a UAV such as the Global Hawk. Feature Set – A military computer may have features not found on a consumer grade computer such as Circular connectors, hot swap power supplies, hot swap fans, custom front panel features such as LCD displays, so forth; the Armed Forces have many numerical designations for computers or other equipment, to guide the military buyer's choice of appropriate technology for their application. For instance, MIL-S-901D would indicate that the computer passed shock and vibration requirements of specific tests for Navy installation; some of these tests are specific to application usage, such as barge explosion testing, which simulates a torpedo hit and subsequent high peak shock to a ship on which the computer is installed. The "gold standard" of testing for compliance with 901D is the Barge Test. A Barge Test is performed four times, each time placing 60 lbs HBX-1 explosive 24 feet under water, starting at 40 feet away at 30, 25 and 20 feet.
In addition, the tests are performed in a fore-and-aft orientation to simulate an explosion at the bow or stern of the ship and athwartship to simulate an explosion by the side of the ship. A video of a barge test can be viewed. Other more common requirements are MIL-STD-810 for environmental testing such as storage and operating temperature, salt spray, etc. Another common specification is MIL-STD-461 for electromagnetic compatibility. There are specifications for workmanship, packaging, so forth, that military computers are required to meet. More on MIL Standards and Specifications at Defense Standard. To meet the challenges of defending the U. S. cyber network, the U. S. military has taken steps to improve the security of devices connected to Department of Defense information networks. According to United States Cyber Command, "Cyber threats demand new approaches to managing information, securing information, ensuring our ability to operate."All military computers must conform to the latest FIPS 140 standards which specify the latest requirements for cryptography modules on devices used throughout the U.
S. government. FIPS 140-3 under development, will address new requirements to face existing
Hotel El Convento is a hotel in Old San Juan, Puerto Rico, in an old monastery adjoining the San Juan Cathedral square. The cathedral is the second-oldest cathedral in the Western Hemisphere. Hotel El Convento is the oldest member of the Historic Hotels of America, it was named the premier Small Luxury Hotel in Puerto Rico by the Small Luxury Hotels of the World organization. In 1646, construction began through a petition by King Philip IV of Spain; the Monasterio del Señor San José de la Orden de nuestra Señora del Carmen was founded in 1651 by Doña Ana Lanzós, a wealthy widow who donated her money and her magnificent residence in the street that since bears the name: de las Monjas. Historian María de los Ángeles Castro tells us that the delay in the arrival of a nunnery was due to economic reasons but for lack of since the fortifications of the city were still not complete. Three nuns brought from Santo Domingo served as founders; the building was expanded between 1861 after the original building was torn down.
Governor Fernándo Norzagaray y Escudero helped raising the necessary funds and inspected the work daily. Certain elements stand out in the facade of the chapel, besides the entrance, the pair of Tuscan columns, the two towers and the latticed choir arch; the frieze above the door is interrupted for a legend. The building was closed from 1903 to 1959 and sold. During its conversion to hotel the two towers were removed and the cross that identified the site as a convent. In 1903, it was closed until 1959, under the auspices of Operation Bootstrap, Robert Woolworth started the renovation to turn it into the El Convento Hotel, it reopened in 1962 to the stars of the day, including Rita Hayworth, offering a tranquil, European-style alternative to the glitzy hotels lining the Condado strip. In the 1990s it was renovated again by a team led by Hugh Andrews and Jorge Rosselló, who remodeled other hotels such as La Concha, the Condado Vanderbilt Hotel, it was rechristened as Hotel El Convento, a 4-star small luxury hotel with five stories, a central courtyard where a 300-year old Níspero fruit tree still stands, a pool and jacuzzi on the fourth-floor terrace, great views of Old San Juan, maintaining the same high standard of luxury and style.
Other notable present-day features of this boutique-style hotel include a 24-hour fitness center, a daily manager’s wine and cheese reception, Patio del Níspero open-air restaurant, 24-hour hospitality bar, five versatile meeting rooms, business center, herb garden, a beach club featuring beach privileges in Condado and Isla Verde beaches, more. Hotel El Convento is an Old San Juan institution with more than 365 years of tradition, making it the oldest member of the Historic Hotels of America, it was named the premier Small Luxury Hotel in Puerto Rico by the Small Luxury Hotels of the World organization. List of hotels in Puerto Rico Official site
Michael Pastreich is an American performing arts executive. He became the executive director of the Washington Ballet in May 2019, he has been the longest serving president & CEO of The Florida Orchestra, served for 11 years from the 40th anniversary of the orchestra in 2007 till 2018. During his tenure paid attendance to performances increased by 49 percent, while national attendance to orchestra performances went down. In 2014, the magazine Musical American presented him in their series Profiles in Courage. Major projects to engage the community are cited by the orchestra as being drivers in the orchestra's popularity, he was the executive director of the Elgin Symphony Orchestra in Illinois from 1996 till 2007. In 2005, the Chicago Tribune named him a "Chicagoan of the Year" and credited him with helping to transform "a struggling community ensemble into one of the Midwest's most artistically and financially secure regional orchestras." In 2006, the Illinois Council of Orchestras named him Executive Director of the Year.
He is the son of performing arts executive Peter Pastreich. SPx Podcast 8-7-18 with Michael Pastreich
Odostomia cookeana is a species of sea snail, a marine gastropod mollusk in the family Pyramidellidae, the pyrams and their allies. The epithet in this species refers to Mss J. M. Cooke, of San Diego, The shell is elongate-ovate narrowly umbilicated, yellowish-white, it measures 3.2 mm. The nuclear whorls are obliquely immersed in the first of the succeeding turns; the four post-nuclear whorls are high between the sutures where they are moderately rounded. They are marked by rather strong incremental lines and numerous fine spiral striations; the periphery and the base of the body whorl are somewhat inflated, the latter rounded and marked like the spire. The oval aperture is large; the posterior angle is acute. The outer lip is thin; the inner lipis decidedly oblique, quite curved in the middle and somewhat reflected. It is provided with an oblique fold at its insertion, strong within and tapers to a vanishing point at the free edge of the columella; the parietal wall glazed with a thin callus. This species occurs in the Pacific Ocean off Alaska.
The 2007–08 OPJHL season is the 15th season of the Ontario Provincial Junior A Hockey League. The thirty-five teams of the North, South and West divisions will compete in a 49-game schedule. Come February, the top six teams of each division competed for the Frank L. Buckland Trophy, the OJHL championship; the winner of the Buckland Cup, the Oakville Blades, competed in the Central Canadian Junior "A" championship, the Dudley Hewitt Cup, won. Once successful against the winners of the Northern Ontario Junior Hockey League and Superior International Junior Hockey League, the champion Blades moved on to play in the Canadian Junior A Hockey League championship, the 2008 Royal Bank Cup where they finished last. Couchiching Terriers are back for 2007-08 Streetsville Derbys have moved to Rexdale Oswego Admirals are now Toronto Dixie Beehives Trenton Sting are now Quinte West Pack Toronto Thunderbirds are now Villanova Knights Bancroft Hawks are folding for 2007-08 season Bramalea Blues are folding for 2007-08 season as of February 13, 2008 Note: GP = Games played.
Teams listed on the official league website. Standings listed by Pointstreak on official league website. For the Central Canada Championship, please go to the Dudley Hewitt Cup. For the national championship, please go to the 2008 Royal Bank Cup. Note: E is East, S is South, W is West, N is North, WC is Wild Card. Playoff results are listed by Pointstreak on the official league website. Hosted by the Newmarket Hurricanes in Newmarket, Ontario. Oakville finished first, Newmarket finished second. Round Robin Oakville Blades 5 - Dryden Ice Dogs 1 Newmarket Hurricanes 5 - Sudbury Jr. Wolves 1 Oakville Blades 5 - Sudbury Jr. Wolves 3 Newmarket Hurricanes 7 - Dryden Ice Dogs 1 Oakville Blades 5 - Newmarket Hurricanes 2Semi-final Newmarket Hurricanes 2 - Dryden Ice Dogs 1 OTFinal Oakville Blades 6 - Newmarket Hurricanes 3 Hosted by Cornwall Colts in Cornwall, Ontario. Oakville finished fifth. Round Robin Cornwall Colts 5 - Oakville Blades 4 Weeks Crushers 4 - Oakville Blades 3 OT Oakville Blades 7 - Humboldt Broncos 6 Camrose Kodiaks 6 - Oakville Blades 1 Note: GP = Games played.