1,045 research outputs found

    A systematic revision of the South American freshwater stingrays (chondrichthyes: potamotrygonidae) (batoidei, myliobatiformes, phylogeny, biogeography)

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    Three genera are recognized in the family Potamotrygonidae of neotropical freshwater stingrays: Potamotrygon, Paratrygon, and Plesiotrygon, the latter being described as a new genus. Potamotrygon is polytypic, and both Paratrygon and Plesiotrygon are monotypic, as far as known. The family name Potamotrygonidae has priority over Paratrygonidae Gill. Nineteen previously described species of Potamotrygonidae are recognized: Paratrygon aiereba, Potamotrygon brachyura, P. castexi, P. constellata, P. dumerilii, P. falkneri, P. henlei, P. histrix, P. humerosa, P. leopoldi, P. magdalenae, P. motoro, P. ocellata, P. orbignyi, P. schroederi, P. schuemacheri, P. scobina, P. signata, and P. yepezi. One additional specific name is established as new (Plesiotrygon iwamae). Three of the eighteen recognized species of Potamotrygon are resurrected from synonymy (P. dumerilii, P. henlei, and P. orbignyi), one previously overlooked subspecific name (Trygon histrix ocellata) is erected to specific rank, and one previously overlooked specific name (Taeniura constellata) is placed in the genus Potamotrygon, and treated as a senior synonym of P. circularis. The remaining names previously assigned to the Potamotrygonidae include: eight junior synonyms (Disceus thayeri, Potamotrygon brumi, P. circularis, P. laticeps, P. menchacai, Trygon mulleri, T. reticulatus, and T. strogylopterus), five doubtful names (Elipesurus spinicauda, Potamotrygon africana, P. alba, P. humboldtii, and Trygon garrapa), two invalid names (Potamotrygon labratoris and P. pauckei), two doubtful names corresponding to one unidentified marine species of the family Dasyatididae (Raja ajereba and R. orbicularis), and one freshwater species of Dasyatis (D. garouaensis) originally described in the genus Potamotrygon. Potamotrygon and Paratrygon are regarded as sister groups, and Plesiotrygon as the primitive potamotrygonid genus, based on a cladistic analysis of stingray characters. Plesiotrygon is restricted to the upper Amazon drainage, and Paratrygon is known from most of the Amazon drainage, occurring also in Rio Orinoco. Eleven species of Potamotrygon have Amazonian distribution (including Rio Tocantins), four of which occur also in other drainages. Four species of Potamotrygon are apparently endemic to Rio Paraguay and lower Rio Parana drainages (P. brachyura, P. falkneri, P. histrix, and P. schuemacheri); P. yepezi is endemic to the Maracaibo basin in Venezuela; P. magdalenae is endemic to Rio Magdalena and Rio Atrato drainages in Colombia, and P. signata is apparently endemic to Rio Parna(\u27)iba drainage in Brazil

    Resource partioning between sympatric congeners - a case study of river rays (Potamotrygon spp.) in the Amazon estuary

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    The syntopic occurrence of different species of freshwater stingray on a small fluvial island at the mouth of the Amazon River led to the investigation of the factors that underpin this coexistence. Stingrays were collected every two months from March 2012 to January 2013 and their exact sampling location was recorded and their stomach contents preserved and analyzed. Data were used to calculate the Levins’ index of niche breadth and Pianka’s index of niche overlap. The combined analysis of these two indices revealed four distinct scenarios, with only one of them favoring interaction between species, when feeding resources were scarce and patchily distributed. The latter conditions were found at two distinct moments during the study period – the peak of the flood and the peak of low water – whereas in other periods, the prevailing conditions were not conducive to resource sharing

    TAMANHO POPULACIONAL E USO DE HABITAT DE UMA ASSEMBLEIA DE RAIAS DE ÁGUA DOCE (POTAMOTRYGONIDAE) NA REBIO DO PARAZINHO (MACAPÁ, AMAPÁ)

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    The assemblage research may provide valuable information on the different ways distinct species respond to varied ecological factors. Tagging and recapturing are useful techniques used in the estimation of population parameters of populations with members that can be individually tagged and that cannot be consistently found. . The aim of this study was to investigate the patterns of the freshwater stingray population and the community population of the taxocene at the Reserva Biológica (REBIO) in Parazinho. Samples were collected every 2 months from March 2012 to January 2013 using a bottom longline with 50 hooks each and were monitored during every receding tide; a cast net, jigging, and drift net were also used. The stingrays were internally tagged with a Passive Integrated Transponder (PIT) microchip, which was inserted near the base of the tail; these stingrays were then released at the same capture site. The Jolly-Seber method was used for the estimation of population parameters for the taxocene. A total of 115 stingrays were captured, 7 of which were recaptured. These 115 stingrays comprised 8 different species classified as follows: Paratrygon aiereba, Potamotrygon motoro, Potamotrygon orbignyi, Potamotrygon scobina, Potamotrygon constellata, Potamotrygon cf. dumerilii, Potamotrygon sp., and Potamotrygon sp 1. The estimated size of the taxocene was very high, which was probably due to the active movement of the stingrays. The number of recaptures was high, and individuals were mainly recaptured from the same initial capture site. The stingrays also showed preference for areas with muddy soils.Keywords: Potamotrygon; marking; Jolly-Seber. O estudo de assembleias de organismos pode fornecer informações valiosas sobre as diferentes formas pelas quais distintas espécies respondem a diferentes fatores ecológicos. A marcação e recaptura são técnicas úteis para o estudo de parâmetros populacionais de populações cujos indivíduos podem ser marcados individualmente, e onde os animais são difíceis de localizar. O objetivo deste trabalho é mostrar quais os padrões de utilização da REBIO do Parazinho pelas populações de raias de água doce e o continente populacional da assembleia. As coletas aconteceram bimestralmente, de março de 2012 a janeiro de 2013,  por meio de espinhéis de fundo com 50 anzóis cada, vistoriados a cada maré vazante, além de tarrafas, zagaias e tapagem de canais de maré. As raias foram marcadas internamente com microchip do tipo PIT (Passive Integrated Transponder) inserido na região próxima à base da cauda e então liberadas no mesmo local de sua captura. O método Jolly-Seber foi usado para estimar os parâmetros populacionais da assembleia. Houve a captura de 115 raias e 7 recapturas, sendo 8 espécies diferentes identificadas como: Paratrygon aiereba, Potamotrygon motoro, P orbignyi, P. scobina, P. constellata, P. cf. dumerilii, Potamotrygon sp. e Potamotrygon sp 1. O tamanho estimado da assembleia foi muito alto, provavelmente devido à sua movimentação ativa. O número de recapturas foi alto e os indivíduos foram preferencialmente recapturados no mesmo local de sua primeira captura. As raias também mostraram preferência pelas áreas com substrato de lama.Palavras-chave:Potamotrygon, marcação, Jolly-Seber

    A study on friendship as educational strategy: its meaning by medical students

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    Objective: To diagnose Friendship as a teaching device. Methods: Exploratory and descriptive qualitative study. Main question: What does Friendship mean and a friendly teacher? Results: Psychosomatic Medicine classroom, 2015/2nd Semester; 16 white students of 6th, 7th and 8th semesters of medical school; two at 2nd graduation; 12 female/4 male; mean age 25 years; most have two siblings; from Southeast and one from Midwest; three were married; two had children. Friendship as a feature of human essence, a communication of the sensitive body. They think teacher as someone fulfilling their will. Conclusion: Educational activities in education, training and health actions should include feeling and will of students. The teachers need to acquire teaching skills of human spirituality

    Uso de lopinavir/ritonavir associado com ergotamina resultando em amputação de pé: comunicação breve

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    Mulher de 32 anos infectada pelo HIV 1, vinha utilizando zidovudina/lamivudina 300/150 mg um comprimido duas vezes ao dia e lopinavir/ritonavir 200/50 mg dois comprimidos duas vezes ao dia e profilaxia com sulfametoxazol-trimetoprim 800/160 mg uma vez ao dia, sem profilaxia com macrolídeos. A paciente apresentou enxaqueca severa com prescrição da associação tartarato de ergotamina 1 mg, cafeína 100 mg, paracetamol 220 mg, sulfato de hiosciamina 87,5 mcg, sulfato de atropina 12,5 mcg, dois comprimidos na crise, seguido de um comprimido a cada 30 minutos, com no máximo seis comprimidos ao dia. A paciente ingeriu seis comprimidos em um dia, surgindo uma dor em tornozelo esquerdo três dias depois, que evoluiu para ergotismo e amputação do pé.A 32-year-old female, was diagnosed in 2004 with a C1 HIV1 infection, using zidovudine/lamivudine 300/150 mg BID and lopinavir/ritonavir 400/100 mg BID, in addition to prophylaxis with trimethoprim-sulfamethoxazole 800/160 mg QD, but no prophylaxis with macrolide antibiotics. The patient presented with a severe headache and was prescribed two capsules of the anti-migraine drug Ormigrein™, which contained ergotamine tartrate 1 mg, caffeine 100 mg, paracetamol 220 mg, hyoscyamine sulfate 87.5 mcg, and atropine sulfate 12.5 mcg. Afterwards she was prescribed one capsule of Ormigrein every 30 minutes for a total of six capsules a day. The patient took the medication as prescribed but developed a pain in her left ankle three days later, which evolved to the need for amputation

    Heterogeneidade celular nos tumores malignos de mama: implicação clínica do estudo de receptores hormonais

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    Conforme demonstrado, os tumores malignos não são entidades uniformes, constituídas por células com características idênticas. Utilizando método histoquímico direto por conjugado hormonal fluorescente, mostra-se que os carcinomas mamários são compostos por população heterogênea, de células receptor-positivas e receptor-negativas em diversas proporções. Nossos resultados comprovam que poucos tumores malignos de mama podem ser considerados como totalmente hormônio-dependentes. Isto explicaria por que em alguns tumores ER+e PgR+, obtêm-se apenas respostas parciais ou curtas remissões pela hormonioterapia. As dificuldades inerentes à racionalização do tratamento são analisadas

    Incidence of Dentinal Defects and Vertical Root Fractures after Endodontic Retreatment and Mechanical Cycling

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    Introduction: The aim of this study was to evaluate the incidence of dentinal defects and vertical root fractures (VRFs) after endodontic retreatment and mechanical cycling (MC). Methods and Materials: Two hundred mandibular premolars were selected. Forty teeth were left unprepared (control group). The remaining 160 root canals were prepared with ProTaper instruments and filled by using two different techniques [eighty with lateral compaction (LC) and eighty with single-cone (SC)]. Forty canals from each group (LC and SC) received no further treatment. The remaining eighty teeth were divided into two groups (LCR and SCR) (n=40) in order to undergo the removal of the root filling, re-preparation and refilling with lateral compaction and single-cone, respectively. All of the teeth were subjected to MC (1,000,000 cycles, 130 N, 2.2 Hz and 37°C). The roots were sectioned at 3, 6 and 9 mm from the apex and observed under 20× magnification. The defects were classified as: no defect, VRF and other defects. Statistical analysis was performed using the Fisher’s Exact test and the Chi-Squared tests (α=0.05). Results: MC alone did not promote any other defects or VRFs. Experimental groups presented higher dentinal defects than the control group (P=0.021). Retreatment groups did not present a higher amount of dentinal defects than the groups that were subjected to the first treatment (P>0.05). Conclusion: Endodontic treatment and retreatment, regardless of the filling technique and MC, did not influence the occurrence of dentinal defects or VRFs in the human premolars.Keywords: Defects; Endodontics; Retreatment; Root Cana

    Secondary syphilis presenting as a corymbiform syphilide: case report and review

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    It is essential that healthcare providers are familiar with the full spectrum of clinical presentations of syphilis. A rare manifestation of secondary syphilis is the corymbiform (or corymbose) arrangement, in which a central greater papule is surrounded by smaller satellite lesions. Very few reports of corymbiform syphilis are available in current biomedical databases. We present the case of a 28 year-old HIV-infected male patient on regular, successful antiretroviral therapy who developed an asymptomatic corymbiform maculopapular lesion in the medial aspect of the right thigh. There were also a few brownish macular lesions on the left sole. New serological tests for syphilis (which had been negative in the past) were reactive. The coymbiform lesion slowly regressed and the non-treponemal test reverted to negative after benzathine penicillin G treatment. A review of the literature is provided. This is the first report of corymbiform syphilis in an HIV-infected patient
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