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| Registros recuperados: 239 | |
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| Tonini,Helio; Schwengber,Dalton Roberto; Morales,Marina Moura; Magalhães,Ciro Augusto de Souza; Oliveira,Jane Maria Franco de. |
| Abstract: The objective of this work was to assess the effect of spacing on the growth, biomass allocation, and wood quality for energy purposes of Acacia magium. A randomized complete block design was carried out with three replicates and five treatments consisting of trees planted at different spacings: 2.0x2.0, 2.5x2.5, 3.0x2.0, 3.0x2.5, and 3.0x3.0 m. At 67 months after planting, the following species parameters were evaluated: performance (mortality, diameter growth, height, bark factor, and bark and biomass volume yield) and wood energy quality (basic density, higher-calorific value, ash, fixed carbon, and volatile materials) through the analysis of variance. Plant spacing did not affect volume and biomass production per hectare nor wood quality for... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Amazon; Biomass accumulation; Energy productivity; Forest plantation; Roraima. |
| Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2018000700791 |
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| Andrade,Eva Santos de; Garcia,Silvana dos Santos Carvalho; Albernaz,Ana Luisa Kerti Mangabeira; Tomazello Fillho,Mario; Moutinho,Victor Hugo Pereira. |
| ABSTRACT: Euxylophora paraensis Huber - Rutaceae, popularly known as yellow heart, is a species with a low-density population that has suffered intense exploitation in recent decades. This has led to its inclusion in the IBAMA list of endangered species. This study aimed to evaluate the existence of growth rings and their annuity in five trees of Euxylophora paraensis through the x-ray microdensitometry technique, as well as to compare them using the classical method. Application feasibility of this technique can be deepened through future, broader dendroecological studies, which may better elucidate the understanding of the species population dynamics and promote more sustainable uses. Wood disks were collected from the base of five 29-year-old trees from... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Dendrochronology; Yellow heart; Density; Amazon. |
| Ano: 2017 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-84782017000400501 |
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| HELENBROOK,William. D.; WILKINSON,Madison L.; SUAREZ,Jessica A.. |
| ABSTRACT The black-headed night monkey, Aotus nigriceps, has one of the largest distribution ranges of the 11 night monkey species found across Central and South America. Yet, only three studies have focused on their ecology, describing considerable variation in habitat, group composition, and population density. Therefore, we analyzed habitat use, group composition, population density, and diet of 14 groups at two field sites in southeastern Peru. All sampled groups were found in secondary tropical rainforest, often dominated by native bamboo species. Half of the observed sleeping sites were in bamboo stands, though groups also emerged from cane thickets and lianas. This contrasts with other Aotus studies which have found groups living in tree cavities... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Amazon; Primates; Aotidae; Conservation; Owl monkey; Nocturnal; Habitat. |
| Ano: 2020 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0044-59672020000100037 |
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| Ohara,Willian Massaharu; Loeb,Marina Vianna. |
| Abstract The fishes herein included were collected in four small streams of the upper rio Tapajós basin. Through fieldwork carried out in 2011, 2013 and 2014 during the low water season 1.728 specimens belonging to 22 species distributed in 11 families, and five orders were captured. Characidae was the most representative family both in number of species and specimens captured. The most abundant species were Hyphessobrycon melanostichos, H. hexastichos, and H. notidanos. Five species are recognized as new, and four as endemic to the upper rio Tapajós basin. This study represents the first fish inventory for the region and will provide valuable information for the conservation of the poorly known diversity of fishes of the Chapada dos Parecis, in the... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: South America; Neotropical fish; Amazon; Endemism. |
| Ano: 2016 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1676-06032016000400302 |
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| Mendes,Humberto Fonseca; Andersen,Trond. |
| Jururumberus n. gen. is erected based on the males of J. arapuca n. sp. from São Paulo State, in southeastern Brazil and J. uatuma n. sp. from the Amazonas in northern Brazil. The genus can be separated from other Orthocladiinae based on the combination of bare eyes, wing, and squama; frons U-shaped, extended ventrally; AR ≤ 0.3, antenna without apical seta; palp short, five-segmented, with sensilla clavata in subapical sensillum coeloconicum; no acrostichals; costa strongly extended; R4+5 ending proximal to M3+4; anal point narrowly triangular with microtrichia only, sitting high on tergite IX; and virga composed of two spines. |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Chironomidae; Orthocladiinae; Jururumberus; New genus; New species; Brazil; Neotropical region; Mata Atlântica; Amazon. |
| Ano: 2013 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1676-06032013000400071 |
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| Ramirez-Gil,H.; Feldberg,E.; Almeida-Val,V.M.F.; Val,A.L.. |
| Karyological characteristics, i.e., diploid number, chromosome morphology and nucleolus organizer regions (NORs), biochemical characteristics, i.e., electrophoretic analysis of blood hemoglobin and the tissue enzymes lactate dehydrogenase (LDH), malate dehydrogenase (MDH), alcohol dehydrogenase (ADH), and phosphoglucose isomerase (PGI), and physiological characteristics, i.e., relative concentration of hemoglobin and intraerythrocytic concentrations of organic phosphates were analyzed for the species Callophysus macropterus collected from Marchantaria Island (white water system - Solimões River) and Anavilhanas Archipelago (black water system - Negro River). Karyological and biochemical data did not reveal significant differences between specimens... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Callophysus; Fish; Amazon; Population genetics; Adaptation. |
| Ano: 1998 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X1998001100014 |
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| Sá,Natália de Paula; Absy,Maria Lúcia; Soares,Emílio Alberto Amaral. |
| ABSTRACT The core PD-67 of 160 cm depth was collected from the delta of Lake Cabaliana situated on the Solimões River. Seventeen samples were removed for palynological and sedimentological analysis and three for radiocarbon analysis. Two dry periods, both in the Late Holocene, were observed (2800-2550 cal yr BP, 1450-550 cal yr BP) separated by a wetter phase (2550-1450 cal yr BP). In 2800-2550 cal yr BP, varzea forests of Alchornea, Symmeria, Cecropia, Alternanthera and Asteraceae were predominant. Beginning in 2,550-1450 cal yr BP, the varzea was characterized by pioneer elements, such as Cassia, Laetia, Mabea, Symmeria and Cecropia, and by the expansion of Poaceae, Cyperaceae, Sagittaria, Montrichardia and Asteraceae. In 1450-550 cal yr BP the... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Amazon; Pollen; Quaternary; Rainfall; Terra firme forest. |
| Ano: 2016 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-33062016000300473 |
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| ARIANO,Ana Paula Ramos; SILVA,Ivone Vieira da. |
| ABSTRACT Leaves have a variety of morphological and anatomical characters mainly influenced by climatic, edaphic and biotic factors. The aim of this study was to describe the anatomical leaf traits of Qualea parviflora from three phytophysiognomies. The studied phytophysiognomies were Amazon Savannah on rocky outcrops (ASR), Transition Rupestrian Cerrado (TRC), and Cerradão (CDA). Freehand sections of the leaf blade were made and stained with 0.5% astra blue and with basic fuchsin. From the adaxial and abaxial leaf surface, freehand paradermal sections were made for epidermis analysis. The Jeffrey´s method, with modifications, was used in the epidermis dissociation process. The samples from the TRC phytophysiognomy had relatively smaller ordinary epidermal... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Adaptations; Amazon; Cerrado; Environmental conditions. |
| Ano: 2016 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0044-59672016000200119 |
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| Montag,Luciano Fogaça de Assis; Freitas,Tiago Magalhães da Silva; Raiol,Roberta Dannyele de Oliveira; Silva,Marlene Vasconcelos da. |
| This paper describes the length-weight relationship, size at first maturation (L), and breeding season of Poecilia reticulata found in drainage channels on the campus of the Federal University of Pará (UFPA) in the Brazilian city of Belém. A total of 1.936 specimens (942 males and 994 females) were collected in monthly samples of the study area between June, 2006, and March, 2007. Females were significantly longer and heavier than males. The length-weight relationship for males was established by the equation Pt = 5 × 10-5 × Ct2.397 and for females by Pt = 3 × 10-6 × Ct3.419. The estimated value of L was 17.5 mm for males and 20.4 mm for females, suggesting that males initiate reproductive activity at a smaller size than females. The abundance of mature... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Fish ecology; Urban environments; Breeding; Amazon; Poecilia reticulata. |
| Ano: 2011 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1676-06032011000300007 |
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| Matsuo,A.Y.; Val,A.L.. |
| The present study analyzes Na+ and K+ disturbances caused by low pH in two catfish species from the Amazon River. Corydoras adolfoi inhabits ion-poor, black-stained, low pH (3.5-4.0) waters, while C. schwartzi is native to ion-rich waters at circumneutral pH. Fish were exposed to pH 3.5 Ca2+-free, and Ca2+-enriched (~500 µmol/l) water to determine the protective effects of calcium. Net Na+ and K+ fluxes were measured in the water collected from the fish experimental chambers. C. adolfoi was unable to control the Na+ efflux at low pH, exhibiting Na+ loss up to -594 ± 84 nmol g-1 h-1 during the first hour. After 3 and 6 h, net Na+ flux increased by 7- and 23-fold, respectively. In C. schwartzi, at pH 3.5, the initial high Na+ loss (-1,063 ± 73 nmol g-1 h-1)... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Low pH; Calcium; Blackwater; Net Na+ and K+ flux; Amazon; Catfish. |
| Ano: 2002 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2002000300012 |
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| Bertani,Rogério; Cruz,Wanessa Ribeiro; Oliveira,Maria Ermelinda do Espírito Santo. |
| A new species of Masteria L. Koch, 1873 from Manaus, Brazil, Masteria manauara sp. nov., is herein described. The specimens were collected by hand or using litter bags in the leaf litter around Attalea attaleoides (Barb. Rodr.) palm trees. The new species resembles Masteria colombiensis Raven, 1981 by lacking paraembolic apophysis on male copulatory organs and having spiniform apophysis on the ventral metatarsus I. It differs in the tibial spur, made of two subdistal, spiniform and converging spurs. Females are unique in having two spermathecae with slender helicoidal stalks. Males and females have only six eyes, and are tiny, even when compared with other Masteria species. |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Amazon; Attalea attaleoides; Leaf litter; Mygalomorphae; Taxonomy. |
| Ano: 2013 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1984-46702013000400010 |
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| Chippari-Gomes,Adriana R.; Leitão,Marco Aurélio B.; Paula-Silva,Maria de Nazaré; Mesquita-Saad,Lenise S. B. de; Almeida-Val,Vera Maria F.. |
| In this paper, we describe the enzyme levels and isozyme distribution in skeletal and heart muscle of Satanoperca aff. jurupari, (Cichlidae, subgroup Geophaginae). LDH and CS were measured in skeletal and heart muscle. Starch gel electrophoresis was used to determine the isozyme/allozyme patterns in different tissues; LDH, MDHs, PGM, PGI, ADH, G-6-PDH and SOD were screened for the numbers of loci, presence of alleles, and tissue specificity. The LDH/CS ratio in heart and skeletal muscle were 173.36 and 6.1, respectively, indicating anaerobic metabolism in the former and aerobic metabolism in the latter muscle. No inhibition by pyruvate (based on the ratios of LDH activity with 1 mM and 10 mM pyruvate) was detected in heart and skeletal muscle, indicating... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Cichlid; Plasticity; Metabolism; Enzymes; Amazon. |
| Ano: 2003 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572003000100005 |
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| Bertani,Rogério; Fukushima,Caroline Sayuri; Nagahama,Roberto Hiroaki. |
| The monotypic diplurid Metriura Drolshagen & Bäckstam, 2009 is placed in synonymy with Fufius (Cyrtaucheniidae) syn. nov. since Metriura lacks two of three diplurid synapomorphies (elongate posterior lateral spinnerets and the widely separated posterior median spinnerets) and shares synapomorphies with both aporoptychine cyrtaucheniids (subquadrate maxilla and a longer than wider labium) and Fufius (recurved and broad fovea, the typical incrassate tibia I of the male, with the spur having a single short branch and an apical megaspine, the basally curved metatarsus I and provided with a ventral tubercle). The type species of Metriura, M. striatipes Drolshagen & Bäckstam, 2009 is considered valid, and due to the synonymy of Metriura with... |
| Tipo: Info:eu-repo/semantics/other |
Palavras-chave: Amazon; Mygalomorphae; Synonymy; Taxonomy. |
| Ano: 2012 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1984-46702012000500016 |
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| Registros recuperados: 239 | |
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