Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 10 de 10
Filtrar
Mais filtros










Intervalo de ano de publicação
1.
Zootaxa ; 5297(1): 1-47, 2023 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-37518811

RESUMO

A new species of Scleronema (Trichomycteridae) is described from the lowlands of three coastal river basins in the Atlantic Forest of the Santa Catarina state, Southern Brazil. Aspects of the anatomy, reproduction, diet, feeding behavior and habitat of the new species are described and discussed in comparison with related taxa. The conservation status of the new species, which currently faces several threats due to environmental impacts on its region of occurrence, is established. Based on characteristics observed in the new species, as well as in most of its congeners, the phylogenetic position and monophyly of Scleronema are discussed and traits considered synapomorphic for the subgenera Plesioscleronema and Scleronema are reviewed. The monophyly of the genus Scleronema is supported by a new synapomorphy. In addition, two new synapomorphies, one of which based on behavior, are suggested for the subgenus Scleronema, justifying the inclusion of the new species. Within the subgenus Scleronema, the new species is assigned to the S. minutum group, which currently includes the majority of species of the genus, due to the presence of synapomorphic traits related to the body shape, maxillary barbel, skin flap of the opercle, caudal and pectoral fins, as well as osteological features of the lower jaw, hyoid arch, and postcranial axial skeleton. The species herein described differs from all its congeners by a combination of characters from various morphological complexes, which are described in detail using different methodologies, including radiography, whole-specimen clearing and double-staining procedures, and tridimensional computer nanotomography (3D nano-CT).


Assuntos
Peixes-Gato , Floresta Úmida , Animais , Filogenia , Brasil , Ecossistema
2.
Physica A ; 564: 125498, 2021 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-33204050

RESUMO

We are currently living in a state of uncertainty due to the pandemic caused by the SARS-CoV-2 virus. There are several factors involved in the epidemic spreading, such as the individual characteristics of each city/country. The true shape of the epidemic dynamics is a large, complex system, considerably hard to predict. In this context, Complex networks are a great candidate for analyzing these systems due to their ability to tackle structural and dynamic properties. Therefore, this study presents a new approach to model the COVID-19 epidemic using a multi-layer complex network, where nodes represent people, edges are social contacts, and layers represent different social activities. The model improves the traditional SIR, and it is applied to study the Brazilian epidemic considering data up to 05/26/2020, and analyzing possible future actions and their consequences. The network is characterized using statistics of infection, death, and hospitalization time. To simulate isolation, social distancing, or precautionary measures, we remove layers and reduce social contact's intensity. Results show that even taking various optimistic assumptions, the current isolation levels in Brazil still may lead to a critical scenario for the healthcare system and a considerable death toll (average of 149,000). If all activities return to normal, the epidemic growth may suffer a steep increase, and the demand for ICU beds may surpass three times the country's capacity. This situation would surely lead to a catastrophic scenario, as our estimation reaches an average of 212,000 deaths, even considering that all cases are effectively treated. The increase of isolation (up to a lockdown) shows to be the best option to keep the situation under the healthcare system capacity, aside from ensuring a faster decrease of new case occurrences (months of difference), and a significantly smaller death toll (average of 87,000).

3.
Talanta ; 222: 121444, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33167198

RESUMO

The development of simple detection methods aimed at widespread screening and testing is crucial for many infections and diseases, including prostate cancer where early diagnosis increases the chances of cure considerably. In this paper, we report on genosensors with different detection principles for a prostate cancer specific DNA sequence (PCA3). The genosensors were made with carbon printed electrodes or quartz coated with layer-by-layer (LbL) films containing gold nanoparticles and chondroitin sulfate and a layer of a complementary DNA sequence (PCA3 probe). The highest sensitivity was reached with electrochemical impedance spectroscopy with the detection limit of 83 pM in solutions of PCA3, while the limits of detection were 2000 pM and 900 pM for cyclic voltammetry and UV-vis spectroscopy, respectively. That detection could be performed with an optical method is encouraging, as one may envisage extending it to colorimetric tests. Since the morphology of sensing units is known to be affected in detection experiments, we applied machine learning algorithms to classify scanning electron microscopy images of the genosensors and managed to distinguish those exposed to PCA3-containing solutions from control measurements with an accuracy of 99.9%. The performance in distinguishing each individual PCA3 concentration in a multiclass task was lower, with an accuracy of 88.3%, which means that further developments in image analysis are required for this innovative approach.


Assuntos
Nanopartículas Metálicas , Neoplasias da Próstata , Antígenos de Neoplasias , Biomarcadores , Biomarcadores Tumorais , Ouro , Humanos , Aprendizado de Máquina , Masculino , Neoplasias da Próstata/diagnóstico
4.
Neotrop. ichthyol ; 12(2): 281-290, Apr-Jun/2014. tab, graf
Artigo em Inglês | LILACS | ID: lil-716336

RESUMO

Astyanax eremus, a new species of geographically isolated characid fish, is described from a small tributary of the upper rio Iguaçu basin. The new species belongs to the Astyanax scabripinnis species complex and is easily distinguished from its congeners included in this group by its allometric growth of the mouth, which goes from terminal in young individuals to subterminal mouth in larger specimens. Additionally, the new species is distinguished by meristic and morphometric characters. Astyanax eremus presents an evident polymorphism on the traditional character "number of teeth in inner premaxillary row". Comments about that character are provided.


Astyanax eremus, uma espécie nova de caracídeo geograficamente isolada, é descrita de um pequeno tributário da bacia do alto rio Iguaçu. A espécie nova pertence ao complexo de espécies Astyanax scabripinnis e é facilmente distinguível dos congêneres deste grupo por apresentar desenvolvimento alométrico da boca, a qual passa de terminal nos indivíduos jovens a subterminal nos maiores. Além disso, a espécie nova é diagnosticada por caracteres merísticos e morfométricos. Astyanax eremus apresenta um acentuado polimorfismo do tradicional caráter "número de dentes da série interna do pré-maxilar". Uma discussão a respeito deste caráter é apresentada.


Assuntos
Animais , Anatomia , Polimorfismo Genético/genética , Rios , Especificidade da Espécie , Peixes/classificação
5.
Neotrop. ichthyol ; 11(1): 33-44, Jan-Mar/2013. tab, graf
Artigo em Inglês | LILACS | ID: lil-670930

RESUMO

A new species of Hyphessobrycon, H. peugeoti, is described from the middle portions of the rio Juruena drainage, upper rio Tapajós basin, Mato Grosso State, Brazil. It can be distinguished from all congeners, with the exception of H. loweae and H. heliacus, by a filamentous elongation of the dorsal fin and the approximately straight margin of the anal fin in adult males. It can be distinguished from both H. loweae and H. heliacus by an overall red coloration in life (vs. a golden coloration in life in the latter). Additionally, it can be distinguished from H. heliacus by the lack of chevron-like dark markings along the midline (vs. presence of chevron-like dark-markings in H. heliacus), and from H. loweae by the presence of only five horizontal scale rows between the dorsal-fin origin and the lateral line (vs. 6-7 in H. loweae), and the higher number of branched anal-fin rays (21-24, modally 22, vs. 17-21, modally 20, in H. loweae). Additional meristic, morphometric, and distributional data are provided for Hyphessobrycon loweae, including its first record in the rio Araguaia/Tocantins basin. Comments on a putative monophyletic group including H. peugeoti, H. loweae, H. heliacus, H. elachys, and H. moniliger are presented.


Uma espécie nova de Hyphessobrycon, H. peugeoti, é descrita do trecho médio da drenagem do rio Juruena, bacia do alto rio Tapajós, estado de Mato Grosso, Brasil. Ela difere de todas as congêneres, com exceção de H. loweae e H. heliacus, pelo alongamento em forma de filamento da nadadeira dorsal e pela margem aproximadamente reta da nadadeira anal em machos adultos. Ela difere de H. loweae e H. heliacus por possuir coloração geral vermelha em vida (vs. colorido dourado em vida em H. loweae e H. heliacus). Além disto, a espécie nova difere de H. heliacus por não possuir marcas em forma de divisas ao longo da linha média do corpo (vs. marcas em forma de divisas presentes em H. heliacus), e de H. loweae por possuir apenas cinco séries de escamas horizontais entre a origem da nadadeira dorsal e a linha lateral (vs. 6-7 em H. loweae) e por possuir elevado número de raios ramificados na nadadeira anal (21-24, moda 22, vs. 17-21, moda 20 em H. loweae). Dados merísticos, morfométricos e de distribuição geográfica adicionais são fornecidos para H. loweae, incluindo os primeiros registros da espécie na bacia do rio Tocantins-Araguaia. Discute-se um grupo presumidamente monofilético que inclui H. peugeoti, H. loweae, H. heliacus, H. elachys e H. moniliger.


Assuntos
Animais , Caraciformes/anatomia & histologia , Characidae/anatomia & histologia , Nadadeiras de Animais/anatomia & histologia , Distribuição Animal , Biometria
6.
Neotrop. ichthyol ; 10(3): 561-566, Sept. 2012. ilus
Artigo em Inglês | LILACS | ID: lil-653598

RESUMO

During recent studies on Parodontidae, specimens of the Venezuelan species Parodon orinocensis (Bonilla, Machado-Allison, Silvera, Chernoff, López & Lasso, 1999) were examined and a few incongruencies with the original description of the species were noted. Emendations to the descriptions of the jaw teeth and color pattern are presented. Three autapomorphies were also observed and are listed herein. The species is moved from genus Apareiodon to Parodon based on presence of dentary teeth.


Durante estudos recentes sobre Parodontidae, espécimes da espécie venezuelana Parodon orinocencis (Bonilla, Machado-Allison, Silvera, Chernoff, López & Lasso, 1999) foram examinados e reconhecidas algumas incongruências na descrição original. Foram realizadas retificações relacionadas aos dentes das maxilas e ao padrão de coloração. Três autapomorfias foram observadas e são aqui listadas. Com base na presença de dentes no dentário a espécie é transferida do gênero Apareiodon para o gênero Parodon.


Assuntos
Animais , Caraciformes/anatomia & histologia , Filogenia , Anatomia Comparada/classificação
7.
Neotrop Entomol ; 40(4): 501-6, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21952969

RESUMO

Entomological surveys in the state of Maranhão have recorded morphologically distinct populations of Lutzomyia longipalpis (Lutz & Neiva). Some populations have one pair of spots (1S) on the fourth tergite, while others have two pairs (2S) on the third and fourth tergites of males. In the present study we investigated the degree of genetic polymorphism among four populations in the municipalities of Caxias, Codó and Raposa, in the state of Maranhão, Brazil, by using RAPD (Random Amplified Polymorphic DNA) markers. A total of 35 loci were identified, of which 30 were polymorphic. The highest polymorphism was observed with primer OPA 4, which produced 11 different profiles. Genetic diversity was assessed using grouping methods that produced a dendrogram in which the genotypes could be clearly separated into two main clades according to the number of spots on the male abdominal tergites. One cluster contained the populations from Caxias and Codó, and the other was formed by the populations from Raposa and Codó. The results of our RAPD analysis showed a clear separation between the populations with one and two pairs of spots. The epidemiologic significance of this genetic differentiation should be investigated in future studies.


Assuntos
Variação Genética , Psychodidae/anatomia & histologia , Psychodidae/genética , Animais , Masculino , Fenótipo , Psychodidae/classificação
8.
Neotrop. ichthyol ; 6(3): 355-366, 2008. ilus, mapas, tab
Artigo em Inglês | LILACS | ID: lil-495163

RESUMO

Rineloricaria langei and R. maacki, new species, are described from upper and middle regions of the rio Iguaçu basin, a left bank tributary of the rio Paraná basin, southern Brazil. Rineloricaria langei has narrow body and is similar to R. quadrensis, which is found in coastal rivers of Rio Grande do Sul State and is distinguishable by several morphometric characters. Rineloricaria maacki is distinguishable from all other congeners by the shape and extension of the naked area of the ventral region of pectoral girdle and other morphological characters. The presence of a naked region on the abdominal surface is shared with other species from the rio Paraná and rio Uruguay basins and coastal drainages from southeastern and southern Brazil. This may indicate a close phylogenetic relationship among these species. Similarities between the two new species and species from the aforementioned drainages also suggest close biogeographic relationship between the Paraná basin and other Brazilian coastal Atlantic drainages throughout the rio Iguaçu basin.


Rineloricaria langei e R. maacki, espécies novas, são descritas para os cursos médio e alto da bacia do rio Iguaçu, tributário esquerdo do sistema do rio Paraná, sul do Brasil. Rineloricaria langei tem o corpo estreito e é semelhante a R. quadrensis, que ocorre nos rios costeiros do estado do Rio Grande do Sul, da qual distingui-se por características morfométricas. Rineloricaria maacki distingui-se de todas as suas congêneres pela forma e extensão da área nua da região ventral da cintura peitoral e outras características morfológicas. A presença de uma região nua na superfície ventral de R. maacki é compartilhada por outras espécies das bacias dos rios Paraná e Uruguai, e das drenagens costeiras do sudeste e sul do Brasil. Isto pode indicar uma proximidade filogenética entre estas espécies. Semelhanças entre as duas espécies novas e espécies das bacias supracitadas também sugerem um relacionamento biogeográfico próximo entre a bacia do Paraná e os rios costeiros brasileiros através da bacia do rio Iguaçu.


Assuntos
Animais , Especificidade da Espécie , Peixes-Gato/classificação , Biodiversidade , Peixes , Ecossistema Tropical
9.
Rev. bras. cir. cabeça pescoço ; 36(2)abr.-jun. 2007. graf
Artigo em Português | LILACS-Express | LILACS | ID: lil-482659

RESUMO

Introdução: Os habitantes da região de Blumenau têm pele clara e são expostos a uma radiação solar com elevado índice ultra-violeta durante o ano. Essas situações associadas favorecem o surgimento do melanoma. Objetivo: estudar o comportamento histológico dos melanomas na região de cabeça e pescoço. Pacientes e Método: Foram analisados todos os casos de melanoma na região de cabeça e pescoço diagnosticados no Laboratório de Anatomia Patológica CIPAC durante o período de janeiro de 2002 e abril de 2005, perfazendo 20 casos. Foram estudadas as seguintes variáveis dos casos: gênero, idade, margens (livres ou comprometidas), presença ou ausência de regressão, invasão angiolinfática e ulceração, além dos critérios de Breslow e Clark. Resultados: Dos 20 casos, 11 correspondiam a mulheres. A idade média foi de 56 anos. Houve predominância histológica do tipo difusão superficial, com 65%. Oito casos tiveram Breslow menor ou igual a 1mm, com Clark II ou III e oito casos tiveram Breslow maior que 1mm, com Clark II ou III. Em três casos, o Breslow era maior que 1mm, com Clark IV ou V. Ulceração ocorreu em 40% dos casos e as margens comprometidas ocorreram em 25%. Conclusão: Os fatores prognósticos de Breslow, Clark, ulceração e índice mitótico estão relacionados ao padrão de crescimento (crescimento superficial, crescimento vertical e ulceração). Os melanomas em região de cabeça e pescoço possuem um comportamento diferente daqueles que aparecem em outras partes do corpo, tendo evolução e prognóstico diferente.


Introduction: The inhabitants of the region of Blumenau City have fair skin and are displayed to solar radiation with high UV index during the year. All those associated situations favor the melanoma sprouting. Objective: to study the histological behavior of the melanomas in the head and neck area. Materials and methods: All cases of melanoma in the head and neck diagnosed in CIPAC Laboratory of Pathology between January, 2002 and April, 2005 were analyzed. The following variable were studied in each case: gender, age, margins (free or not), Clark level, Breslow thickness and presence or absence of regression, angiolymphatic invasion and ulceration. Results: 20 cases were analyzed. Eleven patients were women. The average age was 56. The superficial spread melanoma occurred in 65% of the cases. In 8 cases the Breslow thickness was < 1mm and the Clark level was II or III. In 8 cases the Breslow thickness was > 1mm and the Clark level was II or III. In 3 cases the Clark level was IV or V (the Breslow thickness was >1mm). Ulceration was detected in 40%, and the margins were not free in 25%. Conclusions: The prognostic factors Breslow thickness, Clark level, ulceration and mitotic index are related to the growth behavior of the tumor (radial growth, vertical growth and ulceration). The melanomas in the head and neck have a distinct behavior from those who occur in other parts of the body. As a result, they have different evolution and prognosis.

10.
Cad Saude Publica ; 15(3): 623-30, 1999.
Artigo em Português | MEDLINE | ID: mdl-10502159

RESUMO

This article presents a list of ten sandfly species from the genus Lutzomyia França, 1924 found in the counties of Aldeias Altas, Capinzal do Norte, Caxias, Codó, Coelho Neto, Timbiras, Timon and Tuntum in northeastern Maranhão, Brazil. Presence of sandflies was associated with cases of visceral and cutaneous leishmaniasis. Some 377 specimens were captured indoors with CDC light traps and 1491 specimens in the peridomicile. The species were: Lutzomyia cortelezii, Lutzomyia evandroi, Lutzomyia goiana, Lutzomyia intermedia, Lutzomyia lenti, Lutzomyia longipalpis, Lutzomyia longipennis, Lutzomyia squamiventris, Lutzomyia termitophila and Lutzomyia whitmani. The most abundant species was L. longipalpis (67. 4% and 70.2%) followed by L. whitmani (31.0% and 24.7%). L. longipalpis was captured both indoors and outdoors in all the months studied.


Assuntos
Doenças Endêmicas , Insetos Vetores , Psychodidae/classificação , Animais , Brasil/epidemiologia , Leishmaniose Cutânea/epidemiologia , Leishmaniose Visceral/epidemiologia , Estações do Ano
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...