971 resultados para Steamboats -- Great Lakes (North America) -- History.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Background: Buteo magnirostris, popularly known as roadside hawk belongs to the family Accipitridae, Ciconiiformes. The specimen is common throughout Brazil inhabiting open areas, tolerating disturbed areas very well, but avoiding dense forests. The trematodes are common parasites in the intestines of birds of prey, with scant notice of pathogenic infections. However, severe infections of trematodes Strigeidae family have been previously reported as a cause of anemia, diarrhea, enteritis, weight loss and death. This paper aims to report the occurrence of infection in S. Falconis in B. magnirostris diagnosed by post mortem examination. Case: The specimen of B. magnirostris, male, young was sent for necropsy at the Laboratory of Veterinary Pathology, Federal Rural University of Semi-Arid (UFERSA), Mossoró-RN, Brazil. With a history of apathy, anorexia, diarrhea and death in one course of 24 h. The free bird life and even puppy had been captured for training and practice of falconry shortly before the clinical manifestation of infection (time of captivity uninformed). On physical examination ruffled feathers, cachexia and pallor of skeletal muscle was observed. At necropsy there was severe enteritis with petechiae and accumulation of liquid contents into the duodenum. Fifty-two trematodes were found set in duodenal mucosa. The other organs and structures showed no changes. Fragments of all organs were harvested, fixed in 10% formalin buffered, routinely processed for histopathology and stained with hematoxylin and eosin (HE). Parasites were carefully collected, washed in saline, fixed, processed and identified according to the morphology and taxonomy. Histologically, the lesions were restricted to the duodenum and were characterized by melting, severe atrophy and necrosis of the epithelial cells of the intestinal villi; inflammatory infiltrate (consisting of lymphocytes, plasma cells and eosinophils) in the lamina propria, in addition to trematodes infiltrated the mucosa and lamina propria. These were 60-80 mm in diameter, consisted of parenchymal body enclosed by the integument. In some cross sections of the parasite was possible to observe the presence of cecum, testis and uterus, with some variations between sections; there were also yellowish eggs and coated with a delicate membrane. The trematodes contain approximately 1 mm in length and used as morphology and taxonomy has been identified as S. Falconis. Discussion: S. Falconis is a trematode intestinal parasite of birds of prey, with reports of its occurrence in Europe, North America and Central. In neotropical regions is described the occurrence of the subspecies S. Falconis brasiliana. Although the absence of clinical signs is a common pattern, parasitism by trematodes may become evident, common to captivity stress conditions, and thus infections, even for low pathogenic parasites can cause diarrhea, anorexia, weight loss and death, as reported in this paper. A factor that possibly contributed to the scant notice is its small size, which makes the observation of this parasite in analysis of necropsy in non-pathological conditions and also not familiar with the technical laboratories in the morphological shape of the eggs, which creates difficulty in finding the parasite in parasitological analysis in captive animals. Despite being considered poorly pathogenic trematodes, epidemiologically, the presence of the parasite should be considered a health risk to free-living predators, newly captive in parks, zoos, veterinary hospitals, triage center for wildlife and creators, as they may express pathogenicity in immunosuppressed animals. This work contributes to recording the presence S. falconis parasitizing the duodenal mucosa of B. magnirostris in Brazil.
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The acid weathering of pyrite-bearing Pennsylvanian clastic sedimentary rocks in southeastern Nebraska locally produces the secondary sulfate minerals alunogen, copiapite, epsomite, felsobanyaite/basaluminite, gypsum, halotrichite, jarosite, rozenite, and slavikite. Of these mineral occurrences, four are first-time discoveries in the state or the surrounding region. Slavikite (NaMg2Fe5 (S04)7 (OH) 6• 33H20), which has been reported only once before in North America and from a handful of sites in Europe and South America, was found in abundance at an outcrop at Brownville, NE. The pH values in 1:1 solutions of deionized water of the studied minerals, excluding epsomite, range from 1.94 to 4.82. Therefore, segregations of secondary minerals in themselves are significant microenvironmental reservoirs of acid that can be mobilized during precipitation events. Because of its role in liberating and concentrating ions such as Al3+, Fe2+, Fe3+, Mg3+, and SO42-, acid rock weathering should be considered in local to regional assessments of surface-water and groundwater chemistry. Observations also suggest that rock weathering by the growth of sulfate salts is a potential factor in local hillslope development, one that has not previously been considered in the study area.
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The pathogenesis of South American and North American myxoma viruses was examined in two species of North American lagomorphs, Sylvilagus nuttallii (mountain cottontail) and Sylvilagus audubonii (desert cottontail) both of which have been shown to have the potential to transmit the South American type of myxoma virus. Following infection with the South American strain (Lausanne, Lu), S. nuttallii developed both a local lesion and secondary lesions on the skin. They did not develop the classical myxomatosis seen in European rabbits (Oryctolagus cuniculus). The infection at the inoculation site did not resolve during the 20-day time course of the trial and contained transmissible virus titres at all times. In contrast, S. audubonii infected with Lu had very few signs of disseminated infection and partially controlled virus replication at the inoculation site. The prototype Californian strain of myxoma virus (MSW) was able to replicate at the inoculation site of both species but did not induce clinical signs of a disseminated infection. In S. audubonii, there was a rapid response to MSW characterized by a massive T lymphocyte infiltration of the inoculation site by day 5. MSW did not reach transmissible titres at the inoculation site in either species. This might explain why the Californian myxoma virus has not expanded its host-range in North America.
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Biotic interrelationships in Alaska have so far suffered little from man's attempts to improve upon nature. As a result of these favorable circumstances, biological investigation in Alaska offers unusual opportunity for elucidating problems which can no longer be approached in the more populated parts of North America. One is very fortunate to have the opportunity of working under these conditions, since present trends indicate that Alaska is soon to go by the way of the great wildernesses which once existed in the United States and Canada.
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In spite of the importance of the various species of shrews to the biotic community, several aspects of their ecology remain very incompletely known. The helminths parasitic in the more conspicuous small mammals in North America have been studied more or less completely, but those occurring in shrews have been largely disregarded. This situation is particularly inappropriate when one considers that shrews often constitute the most abundant mammalian group in a given area. We have attempted to secure an adequate amount of shrew helminth material for study, and it is the purpose of this paper to present observations resulting from this work.
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The coyote (Canis latrans) is among the most studied animals in North America. Because of its adaptability and success as a predator, the coyote has flourished and is still expanding its range. Coyotes can now be found throughout most of North America and south into Central America (Voight and Berg 1987). Studies in recent years have been extensive to understand the interrelationships of prey and coyotes (Shelton and Klindt 1974, Beckoff and Wells 1981), as well as demographic relationships (Davis et al. 1975, Knowlton and Stoddart 1978, Mitchell 1979, Bowen 1981) and feeding strategies (Todd and Keith 1976, Andelt et al. 1987, MacCracken and Hansen 1987, Gese et al. 1988a). With the advance of radio telemetry, researchers have investigated lifestyle characteristics spatially with home ranges or temporally with movements in relation to habitat requirements. Researchers have studied home ranges of coyotes in various regions of the United States (Livaitis and Shaw 1980, Andelt 1981, Springer 1982, Pyrah 1984, Gese et al. 1988a) and Canada (Bowen 1982). Some studies of home range were separated by season (Ozoga and Harger 1966) or relation to nearby food sources (Danner and Smith 1980). Home range analysis in relation to social interactions of coyotes has been either neglected, overlooked, or avoided. Gese et al. (1988a) recognized a transient class of coyote by home range size. Coyote social systems are very complex and can vary by season or locality in addition to some reports of group or pack systems (Hamlin and Schweitzer 1979, Beckoff and Wells 1981, Bowen 1981, Gese et al. 1988b). Coyotes maintain communication with conspecifics through vocal and olfactory signals (Lehner 1987, Bowen and McTaggert Cowan 1980). Social interactions may be by far the most complex and least understood aspect related to coyote ecology. Coyote movements can be related to many factors including food, water, cover, and social interactions. Movements in relation to food sources are well documented (Fitch 1948, Todd and Keith 1976, Danner and Smith 1980) although reports on movements in relation to water have not been reported, probably because of limited research in desert situations. There has been some mention of coyotes' movements in relation to cover (Wells and Beckoff 1982). The objectives of this study were to delineate annual and seasonal home ranges, movements, and habitat use of coyotes in the northern Chihuahuan desert.
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H5N1 Influenza Virus in Wild Birds: A Fact Sheet Highly Pathogenic Avian Influenza Virus H5N1 and Wild Birds What are avian influenza viruses? What is a Highly Pathogenic Avian Influenza virus? What is “Bird Flu” and what is “HPAI H5N1”? What do we know about avian influenza viruses in wild birds? Do we have HPAI H5N1 in North America? Is there currently a public health risk associated with HPAI H5N1 in wild birds? Is there a domestic animal health risk associated with HPAI in wild birds? What is the possibility of HPAI H5N1 entering North America via migratory wild birds? What is the possibility of this virus being maintained in wild bird populations? Do we have surveillance for HPAI H5N1 in the United States? Additional information on HPAI can be found at these websites: The recognized geographic and species distribution of chronic wasting disease (CWD) has expanded since early September 2005 to include Hampshire County in the eastern panhandle of West Virginia National Fish and Wildlife Health Initiative Guiding Principles Eastern Equine Encephalitis (EEE) virus was isolated from seven white-tailed deer in southwestern Michigan during September 2005 During the past summer, more than 500 head of livestock in North Dakota and South Dakota were lost to one of the largest recorded anthrax outbreaks in U.S. history. Most of the losses were in cattle, but horses, bison, and farm-reared elk also were affected. Dr. John Fischer, Director of SCWDS, has received this year’s Special Recognition Award from the International Association of Fish and Wildlife Agencies (IAFWA). Dr. William Randolph Davidson is retiring in November 2005.
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We describe an additional saurischian specimen from the Caturrita Formation (Norian) of the Parana Basin, southern Brazil. This material was collected in the 1950s and remained unstudied due to its fragmentary condition. Detailed comparisons with other saurischians worldwide reveal that some characters of the ilium, including the low ventral projection of the medial wall of the acetabulum and its concave ventral margin, together with the short triangular shape of the pre-acetabular process and its mound-like dorsocaudal edge, resemble those of sauropodomorphs such as Plateosaurus and Riojasaurus. This set of traits suggests that MN 1326-V has affinities with basal Sauropodomorpha, probably closer to plateosaurians than to Saturnalia-like taxa. Previous records of this clade in the Caturrita Formation include Unaysaurus, which has been related to Plateosaurus within Plateosauridae. Alternative schemes suggest that plateosaurids include Plateosaurus plus the Argentinean 'prosauropods' Coloradisaurus and Riojasaurus. Both hypotheses raise biogeographic questions, as a close relationship between faunas from South America and Europe excluding Africa and North America is not supported by geological and biostratigraphical evidence. Additionally, the absence of plateosaurids in other continents suggests that the geographical distribution of this taxon is inconsistent with the geological history of western Pangaea, and this demands further investigations of the phylogeny of sauropodomorphs or improved sampling.
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Background: The temporal and geographical diversification of Neotropical insects remains poorly understood because of the complex changes in geological and climatic conditions that occurred during the Cenozoic. To better understand extant patterns in Neotropical biodiversity, we investigated the evolutionary history of three Neotropical swallowtail Troidini genera (Papilionidae). First, DNA-based species delimitation analyses were conducted to assess species boundaries within Neotropical Troidini using an enlarged fragment of the standard barcode gene. Molecularly delineated species were then used to infer a time-calibrated species-level phylogeny based on a three-gene dataset and Bayesian dating analyses. The corresponding chronogram was used to explore their temporal and geographical diversification through distinct likelihood-based methods. Results: The phylogeny for Neotropical Troidini was well resolved and strongly supported. Molecular dating and biogeographic analyses indicate that the extant lineages of Neotropical Troidini have a late Eocene (33-42 Ma) origin in North America. Two independent lineages (Battus and Euryades + Parides) reached South America via the GAARlandia temporary connection, and later became extinct in North America. They only began substantive diversification during the early Miocene in Amazonia. Macroevolutionary analysis supports the "museum model" of diversification, rather than Pleistocene refugia, as the best explanation for the diversification of these lineages. Conclusions: This study demonstrates that: (i) current Neotropical biodiversity may have originated ex situ; (ii) the GAARlandia bridge was important in facilitating invasions of South America; (iii) colonization of Amazonia initiated the crown diversification of these swallowtails; and (iv) Amazonia is not only a species-rich region but also acted as a sanctuary for the dynamics of this diversity. In particular, Amazonia probably allowed the persistence of old lineages and contributed to the steady accumulation of diversity over time with constant net diversification rates, a result that contrasts with previous studies on other South American butterflies.
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[ES] Este trabajo tiene como propósito realizar una primera aproximación al proceso histórico de ocupación de la geografía árida de Norteamérica (1860-1960) que integra la frontera norte de México con el sureste de los Estados Unidos. Se hace énfasis en el impacto general que en este proceso jugó la revolución industrial y tecno-científica que la acompañó y específicamente el papel desempeñado de la Gran Hidráulica en la explotación de los recursos hídricos a gran escala, habilitando el desarrollo productivo y social. Como parte del cambio histórico se expone también la emergencia de un moderno marco jurídico-institucional en torno al agua. Se cierra con la exposición de dos casos regionales para mostrar las crecientes rivalidades por los recursos hídricos ante sus nuevos usos modernos y su explotación intensiva, así como las diferentes modalidades de gestión resultantes y sus impactos en el largo plazo. [EN] This work aims to make a first approach to the historical process of occupation of the arid geography of North America (1860-1960) that integrates the northern border of Mexico with the southeast of the United States. Emphasis on the general impact that this process played the industrial and technoscientific revolution that accompanied it and specifically the role of the great hydraulic in the exploitation of large-scale water resources, enabling productive and social development. As part of the historic change is also the emergence of a modern legal- institutional framework around water. It closes with the exhibition of two regional cases to show the growing rivalries for water resources to its new modern uses and its intensive exploitation, as well as the different forms of management resulting and their impacts in the long term.
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Il presente lavoro di ricerca ha per oggetto il tema della diffusione urbana. Dopo una breve ricostruzione delle varie definizioni presenti in letteratura sul fenomeno - sia qualitative che quantitative - e una descrizione dei limiti di volta in volta presenti all’interno di tali definizioni, si procede con la descrizione dell’evoluzione storica dello sprawl urbano all’interno del mondo occidentale. Una volta definito e contestualizzato storicamente l’oggetto della ricerca, ne vengono analizzate le cause e il complesso sistema di conseguenze che tale fenomeno urbano porta con sé. Successivamente vengono presentate le principali teorie sociologiche attraverso le quali può essere interpretato il fenomeno dello sprawl urbano e vengono descritte le varie forme con cui si può esprimere lo sprawl urbano: non esiste infatti uniformità tra i vari paesaggi suburbani, ma una grande diversità interna alle varie forme in cui si manifesta il fenomeno della dispersione insediativa. Se quanto finora esaminato, soprattutto a livello bibliografico, è riconducibile alla letteratura nordamericana, arrivati a questo punto del lavoro, l’attenzione viene spostata sul continente europeo, prendendo in esame l’emergere del periurbano all’interno del nostro continente e tentando di descrivere sia le contiguità che le differenze tra il fenomeno dell’urban sprawl e quello del periurbano. Infine, adottando un procedimento “ad imbuto”, il lavoro si sofferma sulla situazione del nostro paese in merito alla tematica in questione. L’ultima sezione della ricerca prevede una parte di lavoro empirico. Se, come è emerso nel quadro teorico, molti sono gli elementi che caratterizzano il tema dello sprawl urbano e del periurbano, si è voluto andare a verificare se, ed eventualmente quali, degli elementi descritti, sono presenti in un’area ben delimitata del territorio bolognese, per cercare di capire se si possa parlare di un “periurbano bolognese” e quali caratteristiche esso presenti.
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Die westliche Honigbiene (Apis mellifera) ist von großer ökologischer und ökonomischer Bedeutung. Seit Jahren zeichnen sich in Nordamerika sowie in manchen Teilen Europas rückläufige Bienenvölkerzahlen und eine abnehmende Artenvielfalt innerhalb der Bienenfamilie ab. Mittlerweile ist von einer globalen Bestäuberkrise die Rede und es wird verstärkt nach Möglichkeiten gesucht, um dieser Krise entgegenzuwirken. Eine Konservierung von Bienenspermien in flüssigem Stickstoff ohne Fruchtbarkeitsreduzierung würde die Bienenzucht revolutionieren und stark beschleunigen, da räumliche und zeitliche Restriktionen bei der Wahl des Bienenspermas wegfielen. Zudem wäre eine Möglichkeit zur Sicherung der genetischen Diversität geschaffen. Im Rahmen des hier vorgestellten Projektes wurde eine solche Methode erarbeitet. In umfangreichen Abkühl- und Einfrierversuchen konnte eine neue Konservierungstechnik entwickelt werden, bei der das Kryoprotektivum mittels Dialyse dem Bienensperma zugesetzt wird. Dieses Verfahren erhält die native Spermaform, in der die Spermien parallel und inaktiv in dicht gepackten Clustern vorliegen, und erzielt bisher unerreichte Besamungserfolge. So konnten durchschnittlich 1,25 Mio. Spermien in den Spermatheken besamter Königinnen gezählt werden und davon waren ungefähr 90% motil. Besonders vielversprechend ist jedoch, dass 79,4% der Brut weiblich waren. Ein so hoher Anteil weiblicher Brut konnte bislang nicht erreicht werden und wäre für züchterische Zwecke ausreichend.
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Aortic stenosis has become the most frequent type of valvular heart disease in Europe and North America and presents in the large majority of patients as calcified aortic stenosis in adults of advanced age. Surgical aortic valve replacement has been recognized to be the definitive therapy which improves considerably survival for severe aortic stenosis since more than 40 years. In the most recent period, operative mortality of isolated aortic valve replacement for aortic stenosis varies between 1–3% in low-risk patients younger than 70 years and between 4 and 8% in selected older adults. Long-term survival following aortic valve replacement is close to that observed in a control population of similar age. Numerous observational studies have consistently demonstrated that corrective surgery in symptomatic patients is invariably followed by a subjective improvement in quality of life and a substantial increase in survival rates. More recently, transcatheter aortic valve implantation (TAVI) has been demonstrated to be feasible in patients with high surgical risk using either a retrograde transfemoral or transsubclavian approach or an antegrade, transapical access. Reported 30-day mortality ranges between 5 and 15%) and is acceptable when compared to the risk predicted by the logistic EuroSCORE (varying between 20 and 35%) and the STS Score, although the EuroScore has been shown to markedly overestimate the effective operative risk. One major concern remains the high rate of paravalvular regurgitation which is observed in up to 85% of the patients and which requires further follow-up and critical evaluation. In addition, long-term durability of these valves with a focus on the effects of crimping remains to be addressed, although 3-5 year results are promising. Sutureless biological valves were designed to simplify and significantly accelerate the surgical replacement of a diseased valve and allow complete excision of the calcified native valve. Until now, there are 3 different sutureless prostheses that have been approved. The 3f Enable valve from ATS-Medtronic received CE market approval in 2010, the Perceval S from Sorin during Q1 of 2011 and the intuity sutureless prosthesis from Edwards in 2012. All these devices aim to facilitate valve surgery and therefore have the potential to decrease the invasivness and to shorten the conventional procedure without compromise in term of excision of the diseased valve. This review summarizes the history and the current knowledge of sutureless valve technology.
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Haitian-American author Edwidge Danticat evokes the Haitian tradition of storytelling in many of her novels and short story collections. A tradition formulated by vodou religion and the amalgamation of African cultures, storytelling acts to entertain, educate and enlighten the people of Haiti. Additionally, her novels are often written in the context of traumatic events in Haitian history. While Danticat's works have been studied with focus on their depiction of storytelling and of trauma, little has been done on the restorative power that storytelling provides. In this thesis, I seek to examine the potential for Danticat's characters and works to create narratives that build community, present testimony, and aid traumatized individuals in recovery.