Abstract Microplastics are ubiquitous contaminants of marine ecosystems around the world and Antarctica is no exception. Microplastics can be influenced by sedimentary dynamics mainly on coastal areas where they are more abundant in Antarctica. This study evaluated microplastic contamination in beach environments from two Antarctic Specially Protected Areas, aiming to identify relationships between microplastic numbers and sedimentological parameters on beach sediments. Low numbers of microplastics were found (> 0.5 mm; fibers excluded) – one particle per sample in 4 of 15 samples analyzed – and there is no evidence of widespread contamination. Sedimentological parameters reveal differences between sampled environments, but low numbers of microplastics impaired statistical comparison. All sediment samples are coarse, denoting highenergy depositional environments that are likely little susceptible to microplastic accumulation. Microplastic contamination in the Antarctic coastal ecosystem is heterogeneous, and their detailed characterization assisted by a systematization of methods can improve the understanding of microplastics distribution patterns in the cold coastal ecosystem. exception Areas sediments > ( 05 0 5 0. mm excluded 1 comparison coarse accumulation heterogeneous

Abstract Sulfurization is a pedogenic process that involves pyrite oxidation and strong soil acidification, accounting for the formation of acid sulfate soils. In Antarctica, acid sulfate soils are related to specific parent materials, such as sulfide-bearing andesites in Maritime Antarctica and pyritized sedimentary rocks in James Ross Archipelago. The hypothesis is that the acid sulfate soils of these regions vary according with a climate gradient. The reviewing of current data showed that the acid sulfate soils of warmer and wetter Maritime Antarctica have a greater weathering degree, higher acidity, leaching, phosphorus adsorption capacity, structural development, and well-crystallized iron oxides and kaolinite formation. On the other hand, the sulfurization at the drier region of James Ross Archipelago is counterbalanced by the semiaridity, resulting in lower acidity and higher base contents combined with little morphological and mineralogical evolution besides presence of weatherable minerals in the clay fraction. The sulfurization process interplays with other pedogenic processes, such as the phosphatization in Maritime Antarctica and salinization in James Ross Archipelago. Higher temperatures and soil moisture enhance the pedogenesis, showing that even the Antarctic sulfate soils, which originated from specific parent materials, have their development and characteristics controlled by a clear climatic gradient.

Abstract The majority of ornithogenic soils studied in Antarctica focus on the influence of penguins, wherever little reports evaluated the influence of flying birds on soil genesis. This study aimed to characterize the morphologic, chemic, physic, mineralogic, and micromorphologic ornithogenic soil pockets influenced by flying birds in Snow Island, Maritime Antarctica. Fifteen soil pockets were selected, described, sampled and analyzed, these sites constitute the main areas with intense long-term terrestrial biological activity in Snow Island. In order to investigate the impact of phosphatization, we compared the soil pockets with the surrounding soils and soils affected by penguins. Zone of phosphatization have a high concentration of P, K, and Ca. The XRD patterns for the clay fraction of ornithogenic soils show that phosphate minerals are the main crystalline phases (leucophosphite, minyulite, fluorapatite, and apatite). We show that even under typical periglacial conditions, sites influenced by flying birds present active chemical weathering processes. The phosphatization release exchangeable bases and accelerate mineralogical and micromorphological transformations in soils. Under the current global warming trend and expected sea-level rise, the ornithogenic environments are susceptible to accelerated erosion rates and a great part of these hotspots may be lost for the open sea.

RESUMO Nas últimas décadas, no estado do Mato Grosso do Sul - Brasil, a redução de áreas preservadas pela degradação de biomas e pela destruição de habitat naturais tem favorecido a aproximação de animais - muitos desses, primatas não humanos - em cidades e rodovias, aumentando o número de acidentes e, em alguns casos, de mortes. Novas técnicas cirúrgicas têm sido desenvolvidas, favorecendo essas espécies, como reportado neste trabalho. O paciente macaco bugio foi traumatizado em região facial, envolvendo importantes estruturas vitais, como grupos musculares faciais responsáveis pela apreensão alimentar, mastigação, respiração, defesa e comunicação (vocalização e mímicas), além das estruturas cartilaginosas nasais. No entanto, técnicas cirúrgicas reconstrutivas em face aplicadas e descritas em humanos apresentaram resultados satisfatórios dos pontos de vista anatômico, fisiológico e visual nos macacos bugio, com aceitação deles diante do estresse, com pós-operatório seguro, resultando na reabilitação do paciente primata.

ABSTRACT In the last decades in the State of Mato Grosso do Sul - Brazil, the reduction in the preservation of areas due to the degradation of the biome and destruction of the natural environment has caused animals, mainly in the order of non-human primates, to come closer to towns and highways, increasing the number of accidents and in some cases, deaths. New surgical techniques have been developed that favor these species as explained in this report. The howler monkey patient was traumatized in the facial region damaging important vital structures such as facial muscle groups responsible for swallowing food, chewing, breathing, defense, and communication (vocalization and mimicry), in addition to the cartilaginous nasal structures. However, reconstructive facial surgical techniques, used on humans, showed satisfactory results from an anatomical, functional, and aesthetic point of view in howler monkey, with acceptance of the animal with a safe postoperative period for a full recovery of the primate patient.

Resumo Objetivo: Avaliar em uma amostra de pacientes com distúrbios da diferenciação do sexo (DDS), dados relacionados à idade, ao encaminhamento e sua correlação com as queixas iniciais, ao sexo ao encaminhamento e ao sexo final e diagnóstico etiológico. Métodos: Revisão retrospectiva da idade por ocasião da primeira consulta e motivo dela, sexo social inicial e após definição do diagnóstico, cariótipo e diagnóstico etiológico de todos os casos atendidos em um ambulatório especializado em DDS entre 1989 e 2016. Foram excluídos casos que não compreendiam DDS e diagnósticos de DDS que não cursam comumente com ambiguidade genital, não necessitam de acompanhamento especializado. Resultados: Dos 1.793 casos atendidos, 1.139 foram diagnosticados com algum DDS. Excluíram-se 430 (272 síndrome de Turner, 66 síndrome de Klinefelter e 92 disgenesia gonadal pura), totalizando 709. Desses, 82,9% foram encaminhados por ambiguidade genital, somente um quarto ainda no primeiro mês de vida e 6,6% por atraso puberal, a maioria com 10 anos ou mais; 68,6% tiveram diagnóstico de DDS XY; 22,4% DDS XX e 9% de anomalias dos cromossomos sexuais. Conclusões: Este estudo apresenta a maior casuística na literatura de pacientes com DDS atendidos em um único serviço. O momento de encaminhamento da maioria dos pacientes com ambiguidade genital foi aquém do ideal e casos mais leves de ambiguidade e muitos com manifestações puberais foram encaminhados ainda mais tardiamente. Os resultados reforçam a importância do ensino continuado a profissionais que terão o primeiro contato com esses pacientes, principalmente pediatras e neonatologistas.

Abstract Objective: To evaluate, in a sample of patients with disorders of sex development (DSD), data related to the age at referral and their correlation with the initial complaints, gender at referral, defined gender after diagnosis and etiological diagnosis. Methods: Retrospective review of the age at the first consultation and the reason for it, initial social gender and gender after the diagnosis, karyotype and etiological diagnosis of all cases treated at a DSD outpatient clinic between 1989 and 2016. Cases that did not involve DSD and DSD diagnoses that do not usually involve ambiguous genitalia, thus not requiring specialized monitoring, were excluded. Results: Of the 1793 treated cases, 1139 were diagnosed with some type of DSD. This study excluded 430 cases (272 with Turner's syndrome, 66 with Klinefelter syndrome, and 92 with pure gonadal dysgenesis), thus a total 709 individuals were included. Of these, 82.9% were referred due to ambiguous genitalia; only one-quarter were still in the first month of life, and 6.6% were referred due to pubertal delay, with most of them aged 10 years or older. Of these patients, 68.6% had a diagnosis of XY DSD, 22.4% of XX DSD, and 9% of sex chromosome abnormalities. Conclusions: This study presents the largest series in the literature of patients with DSD treated in a single center. The time of referral of the majority of patients with ambiguous genitalia fell short of the ideal, and milder cases of ambiguous genitalia and many with pubertal manifestations were referred even later. The results reinforce the importance of continuing education for professionals who will have the first contact with these patients, mainly pediatricians and neonatologists.

RESUMO Avaliou-se o efeito da redução do cálcio livre no meio de congelamento, usando-se o quelante de cálcio etilenodiaminotetracético (EDTA) a 0,3% e 0,5%. Três cães machos sem raça definida foram submetidos à coleta de sêmen por manipulação digital (n=16). Cada ejaculado foi diluído em diluidor controle com TRIS-glicose - gema de ovo (TGE, controle), ou em diluidor TGE enriquecido com 0,3% (EDTA 0,3) ou 0,5% de EDTA (EDTA 0,5). A concentração de cálcio reduziu no meio EDTA 0,3, e todos os íons de cálcio foram quelados no meio EDTA 0,5. A adição do EDTA e a consequente quelação do cálcio não afetaram a morfologia espermática ou a integridade da membrana plasmática, no entanto, ao remover todo o cálcio do meio (EDTA 0,5), a motilidade espermática se reduziu (64,7% no TGE e 45% no EDTA 0,5; P<0,05). A integridade do acrossoma e a capacidade de ligação do espermatozoide não melhoraram com a quelação do cálcio. Apesar da influência da concentração de cálcio sobre a motilidade espermática após o descongelamento, a falha em prever a reação acrossomal prematura pode explicar por que a longevidade espermática não foi afetada pela remoção do cálcio no meio. Dessa forma, a remoção parcial ou total do cálcio, por meio da adição de EDTA, não é capaz de prevenir o dano no acrossoma ou a reação acrossomal prematura e, portanto, não aumenta a capacidade do espermatozoide de se ligar ao oócito.

ABSTRACT We evaluated the effect of reducing free calcium in the cryopreservation medium, using the calcium chelator ethylene diamine tetracetic acid (EDTA) at 0.3% and 0.5% concentrations. Three male mixed breed dogs were subjected to semen collection by digital manipulation (n=16). Each ejaculate was divided in three aliquots, and each one was diluted in TRIS-glucose-egg yolk extender with 6% glycerol and 0.5% Equex STM Paste® (TGE, control); and added with 0.3% EDTA (EDTA 0.3) or 0.5% EDTA (EDTA 0.5). Calcium concentration reduced in EDTA 0.3 and all the calcium ions were chelated in EDTA 0.5. The EDTA addition did not affect sperm morphology or plasma membrane integrity; however, by removing all free calcium (EDTA 0.5), the sperm motility reduced (64.7% in TGE and 45% in EDTA 0.5; p<0.05). Acrosome integrity and sperm binding ability were not improved by calcium chelation. The failure to prevent the premature AR may explain why sperm longevity was not affected by calcium removal. Thus, the partial or complete calcium removal, through EDTA addition, is not able to prevent acrosomal damage or premature acrosomal reaction, and therefore does not improve the dog sperm binding ability.

RESUMO Objetivou-se, por meio do presente estudo, avaliar o método de colheita farmacológica de sêmen com sondagem uretral, em machos de onças-pardas (Puma concolor) mantidos em cativeiro. A técnica proposta (Cat; N=3) foi comparada com a eletroejaculação (EE; N=4). Para a colheita farmacológica, utilizou-se medetomidina para induzir a liberação de sêmen na uretra e sonda uretral para gatos, sem janela lateral, para colheita do sêmen por capilaridade. O método foi eficaz em todos os animais usados. Por meio dessa técnica, colheram-se amostras com menor volume (106,7±30,5aµL) e maior concentração (524,1±54,3b x 106 espermatozoides/mL) em relação à EE (450,0±0,1bµL e 205,0±141,8a x 106 espermatozoides/mL). As avaliações de vigor, motilidade e patologia espermática demonstraram que a técnica não afeta a qualidade do sêmen em relação à EE (P>0,05). Dessa forma, o método proposto consiste em uma técnica mais prática e eficiente para a colheita de sêmen com boa qualidade, dispensando o eletroejaculador.

ABSTRACT The aim of this study was to evaluate the pharmacological semen collection method with urethral catheterization (CT) in captive cougar (Puma concolor) males. The pharmacological method (CT; N= 3) was compared to the electroejaculation technique (EE; N= 4). For CT collection, medetomidine was administrated to induce semen release using a tomcat catheter inserted into the urethra to collect by capillarity. The proposed method was efficacious on all animals used. Through the CT method, semen collected yielded smaller volume (106,7±30,5aµL) and higher concentration (524,1±54,3b x 106sperm/mL) compared to EE (450,0±0,1bµL and 205,0±141,8a x 106 sperm /mL). Evaluations of vigor, motility and sperm pathology demonstrated that CT does not affect semen quality when compared to EE (P> 0.05). Thus, the proposed method consists of a more practical and efficient technique for semen collection with good quality, eliminating the need for eletroejaculation.

RESUMO: Alelopatia é o termo utilizado para definir qualquer processo envolvendo metabólitos secundários produzidos por plantas e microrganimos que influenciem no crescimento e desenvolvimento de sistemas agrobiológicos. Na atualidade, busca-se encontrar aleloquímicos de interesse e saber como aplicá-los em bio-herbicidas para combater plantas daninhas. Neste trabalho foram analisados os efeitos do extrato foliar bruto e das frações de Machaerium hirtum (Vell.) Stellfeld em duas espécies daninhas: Euphorbia heterophylla L. (leiteira) e Ipomoea grandifolia (Dammer) O’Donell (corda-de-viola), assim como a ocorrência de alterações morfoanatômicas. Para isso, foram solubilizados e diluídos 0,04 g do extrato bruto e frações (50 mL) até as concentrações de 0,1, 0,2, 0,4 e 0,8 g L-1 (m/v). Os testes de crescimento inicial foram realizados em placas de Petri contendo duas folhas de papel, e as plântulas das espécies daninhas com os tratamentos respectivos, mantidos em câmara de germinação por 48 horas a 25 ºC; utilizou-se como controle dos testes somente água destilada. Foi avaliado no crescimento inicial o comprimento radicular e aéreo. A porcentagem de inibição foi calculada com base nos valores obtidos nos bioensaisos de crescimento inicial. As plântulas de leiteira alteradas morfologicamente foram fixadas e seccionadas transversalmente, para análise anatômica. Os resultados indicaram alterações significativas no comprimento; as plântulas de leiteira foram mais sensíveis que as de corda-de-viola. Plântulas morfologicamente alteradas apresentaram necrose radicular como sintoma mais frequente. Anatomicamente, as células parenquimáticas do hipocótilo e das raízes das plântulas de leiteira apresentaram células menores e com formatos irregulares quando comparadas ao controle, o que ocasionou reduções significativas nos parâmetros mensurados.

ABSTRACT: Allelopathy is the term used to define any process involving secondary metabolites produced by plants and microorganisms that influence growth and development of agrobiological systems. Currently, it is sought to find allelochemicals of interest and know how to apply them in bio-herbicides to combat weeds. In this study, the effects of the crude leaf extract and fractions of Machaerium hirtum (Vell.) Stellfeld were analyzed on Euphorbia heterophylla L. (wild poinsettia) and Ipomoea grandifolia (Dammer) O’Donell (morning glory), as well as the occurrence of morphoanatomical changes. For this, 0.04 g of the crude extract and fractions were solubilized and diluted (50 mL) to concentrations of 0.1, 0.2, 0.4, and 0.8 g L-1 (m/v). Initial growth tests were performed on Petri dishes containing two paper sheets and seedlings of weed species with the respective treatments, being maintained in a germination chamber for 48 hours at 25 oC. Distilled water was used as a control. Shoot and root length was assessed in the initial growth. The percentage of inhibition was calculated based on the values obtained in the initial growth bioassays. Morphologically altered wild poinsettia seedlings were fixed and sectioned transversely for anatomical analysis. The results indicated significant changes in length, being wild poinsettia seedlings more sensitive when compared to those of morning glory. Morphologically altered seedlings presented root necrosis as the most frequent symptom. Anatomically, parenchymatic cells of the hypocotyl and roots of wild poinsettia seedlings presented smaller and irregularly shaped cells when compared to the control, causing significant reductions in the measured parameters.

RESUMO A atividade acaricida do extrato etanólico bruto e das frações das folhas de Morus nigra (Moraceae) foi avaliada no carrapato Rhipicephalus microplus, utilizando-se o teste de imersão de fêmeas ingurgitadas. Foram avaliadas a mortalidade e a fertilidade das fêmeas ingurgitadas, expostas a diferentes concentrações (5, 10 e 25 mg/mL) das frações hexânica, clorofórmica e acetato de etila, bem como do extrato etanólico. Os testes foram realizados em triplicata. O estudo também identificou os principais compostos fenólicos do extrato e das frações dessa espécie por HPLC. A fração clorofórmica das folhas de M. nigra (25mg/mL) apresentou o melhor resultado para essa espécie, obtendo-se 62,6% de inibição da oviposição, 39,3% da eclosão dos ovos e 65,4% de eficácia. A análise por HPLC revelou a presença de compostos fenólicos, os quais podem estar relacionados com a atividade biológica demonstrada pelos extratos, que podem ser utilizados como auxiliar no controle contra carrapato adulto de R. microplus.

ABSTRACT The acaricidal activity of crude ethanolic extract and fractions from the leaves of Morus nigra (Moraceae) was carried out on female cattle ticks Rhipicephalus microplus, using the adult immersion test. The mortality and fertility of females exposed to different concentrations of hexane, chloroform and ethyl acetate fractions, as well as ethanolic extract of M. nigra with concentrations of 5, 10 and 25mg/ml were evaluated using three treatment groups, two control groups and triplicate tests. The study also identified the main phenolic compounds of the extract and fractions of this species by HPLC. The chloroform fraction of leaves of M. nigra (25mg/mL) showed the best results for this species, obtaining 62.6% of inhibition of oviposition, 39.3% of eggs eclosion average and 65.4% of effectiveness. HPLC analysis revealed the presence of phenolic compounds, which may be related to biological activity shown by the extracts, which can be used as an alternative control against R. microplus adult tick.

This study investigated the influence of antihypertensive drugs, such as angiotensin-converting enzyme inhibitors (ACEIs), AT1 receptor blockers (ARBs), voltage-gated L-type calcium channel blockers, and mineralocorticoid receptor antagonists (MRAs), on the effects of angiotensin-(1-7) [Ang-(1-7)] on aorta and coronary arteries from pressure-overloaded rats. Pressure overload was induced by abdominal aortic banding (AB). To evaluate the role of antihypertensive drugs on the effect of Ang-(1-7), AB male Wistar rats weighing 250–300 g were treated with vehicle or low doses (5 mg·kg-1·day-1, gavage) of losartan, captopril, amlodipine, or spironolactone. Isolated aortic rings and isolated perfused hearts under constant flow were used to evaluate the effect of Ang-(1-7) in thoracic aorta and coronary arteries, respectively. Ang-(1-7) induced a significant relaxation in the aorta of sham animals, but this effect was reduced in the aortas of AB rats. Chronic treatments with losartan, captopril or amlodipine, but not with spironolactone, restored the Ang-(1-7)-induced aorta relaxation in AB rats. The coronary vasodilatation evoked by Ang-(1-7) in sham rats was blunted in hypertrophic rats. Only the treatment with losartan restored the coronary vasodilatory effect of Ang-(1-7) in AB rat hearts. These data support a beneficial vascular effect of an association of Ang-(1-7) and some antihypertensive drugs. Thus, this association may have potential as a new therapeutic strategy for cardiovascular diseases.

Objetivou-se com o presente estudo monitorar o comportamento do uso territorial de um macho de onça parda, capturado no Parque Estadual da Serra do Brigadeiro (PESB), por meio da telemetria, usando colar de GPS via Satélite Globalstar. O monitoramento de doze meses resultou na transmissão via satélite de 328 localizações, as quais sugerem que a área utilizada por esse felino seja de aproximadamente 610km2, sendo esta a maior área já descrita para a espécie. Foi possível observar que apenas 20% das localizações ocorreram dentro da área do PESB. O comportamento territorial observado neste trabalho mostra a vulnerabilidade do animal a ações antrópicas, como a caça, atropelamentos e o contato com patógenos entre animais silvestres e domésticos. Observou-se também que duas rodovias configuram barreiras artificiais para o deslocamento do animal, possivelmente impedindo o fluxo gênico entre o PESB e dois outros importantes parques. Com os dados levantados é possível a sugestão de ações de manejo, como a criação de uma conectividade efetiva entre o PESB, o Parque Estadual do Rio Doce e o Parque Nacional do Caparaó, o que poderia contribuir para o intercâmbio genético entre as populações e, dessa forma, favorecer a conservação não somente da onça parda.

We aimed to study the territorial behavior of a male cougar, captured in the Parque Estadual da Serra do Brigadeiro (PESB), using a GPS collar and the Globalstar Satellite. Monitoring the animal for nine months we obtained 328 locations. The data suggest that the area used by this feline is approximately 610km2, the largest area described for this specie. It was also possible to observe that only 20% of the locations of the animal occurred within the PESB area. The territorial behavior observed in this study shows the vulnerability of the animal to human activities such as hunting, road kill and contact with pathogens from domestic animals. It was also observed that two roads constitute artificial barriers for animal movement, possibly preventing gene flow between the PESB and two other parks. The creation of an effective connectivity between the PESB, the Parque Estadual do Rio Doce and the Parque Nacional do Caparaó is critical to ensure genetic exchange between the animal populations and thereby promote their conservation.

O presente trabalho consiste no primeiro relato de criptorquidismo em uma jaguatirica, adulta, de vida livre. Para a captura foram empregadas armadilhas com desarme de guilhotina, usando como isca vísceras de bovino. O animal foi contido quimicamente por meio de dardos anestésicos e mantido sob anestesia, utilizando a associação de cloridrato de quetamina e cloridrato de xilazina. Durante o exame andrológico, observou-se que o testículo esquerdo localizava-se subcutâneo, próximo à região inguinal, caracterizando-se criptorquidismo unilateral. Esse testículo apresentava-se flácido, com volume de 2,57mL, enquanto o testículo contralateral apresentava consistência firme e volume de 11,50mL. A área ocupada pelas espículas penianas mostrou-se compatível com a de animais reprodutores. O criptorquidismo é uma condição hereditária ligada à baixa variabilidade genética, já relatada em felinos silvestres consanguíneos. Nesse sentido, devido ao crescente isolamento populacional em fragmentos florestais, este achado torna-se preocupante, uma vez que pode ser indicativo de endogamia em populações de jaguatiricas de vida livre.

This paper is the first report of unilateral cryptorchidism in an adult wildlife ocelot, captured in Parque Estadual do Rio Doce. Cage traps were used to capture the animal, using bovine offal as bait. The animal was anesthetized with anesthetic darts and kept under anesthesia through a combination of ketamine and xylazine. The andrologycal examination showed that the left testicle was located subcutaneously near the inguinal region. In this case of unilateral cryptorchidism, the testis was soft and had a volume of 2.57mL, while the contralateral testis had a firm consistency and volume of 11.50mL. The length of the region occupied by the penile spikes was similar to other breeding animals. Cryptorchidism is an inherited condition linked to low genetic variability previously reported in consanguineous wild cats. Due to the increasing isolation of wild population in forest fragments, this finding is concerning because it can be indicative of inbreeding in wild ocelot populations.

O entendimento dos processos que causam as diferentes distribuições de corpos silicosos no solo é essencial para a interpretação dos possíveis fatores ambientais responsáveis pela estabilidade deles, deposição de sedimentos, formação de paleossolos e para análise de sítios arqueológicos. Assim, a presente pesquisa objetivou identificar a ocorrência de corpos silicosos encontrados em horizontes superficiais de solos oriundos de diferentes ecossistemas terrestres. Amostras de horizonte superficial de 10 perfis de solo foram coletadas e queimadas em mufla, para remoção da matéria orgânica. Posteriormente, as amostras foram tratadas com HCl 10 cL L-1, para remoção das impurezas contidas na cinza. A fração silte foi obtida por sedimentação, usando o procedimento de análise granulométrica. A maior parte dos corpos silicosos em solos encontra-se na fração silte. Dessa fração, montaram-se lâminas, utilizando óleo de imersão tipo A para identificação dos corpos silicosos em microscópio óptico. A análise dos resultados permitiu observar a variedade de formas e abundância de corpos silicosos nos solos estudados, sendo mais abundantes e diversificados no solo desenvolvido de quartzito. Nos Latossolos, não houve diferença em abundância de fitólitos em relação aos solos dos biomas do Cerrado, Mata Atlântica e Caatinga.

The understanding of the processes that cause the varied distribution of silica bodies in soils is essential for the interpretation of the possible environmental factors related to their stability, sediment deposition, paleosol formation and for the analysis of archaeological sites. Thus, this study had the objective of identifying and characterizing the silica bodies morphology from surface soil horizons collected at different terrestrial ecosystems. Samples of surface horizons were collected from 10 soil profiles and heated in a muffle furnace to remove organic matter. Thereafter the samples were treated with HCl 10 % (vol/vol) to remove the soluble matter contained in each sample. The silt fraction was determined by sedimentation using particle size analysis. Most biogenic silica in soils is associated to the silt fraction. Glass microscope slide containing of this fraction were mounted on an immersion oil type A for silica body identification. The results showed a variety of forms and abundance of silica bodies in the studied soils. The variation in form and abundance was highest in the soil formed from quartzite. No differences in abundance of phytoliths were observed in the Oxisols from the Cerrado, Mata Atlântica and Caatinga biomes.

Apesar da importância agrícola das Terras Pretas de Índio (TPI) na Amazônia - solos de origem pré-colombiana que ocorrem na região do vale do Amazonas/Solimões, cuja fertilidade está relacionada a elevados teores de P, Ca e outros nutrientes - há poucos estudos que relacionem textura e fertilidade nas TPI. Com o objetivo de avaliar os teores totais de P, as formas químicas predominantes e o estádio de transformação desse elemento, foram estudados perfis de TPI situados em áreas com solos de granulometria variável, bem como perfis de solos adjacentes às TPI como referência. A diferença textural do solo nos diferentes sítios estudados indica reflexos na fertilidade, na transformação das formas primárias de P e, consequentemente, nas formas predominantes de P. Em solo de TPI com granulometria variando entre argilosa e muito argilosa foram observados maiores teores de P total e maiores teores da forma primária de P (P-Ca). No sítio de Rio Preto da Eva, com granulometria variando entre franco-arenosa e franco-argiloarenosa, de maneira geral, observaram-se maiores teores de P-Al e menores de P total. As TPI do sítio de granulometria mais argilosa apresentaram maiores teores de P solúvel, extraídos com NH4Cl, os quais são diferentes dos teores extraídos com Mehlich-1.

Despite the agricultural importance of Indian Black Earth (IBE) in the Amazon region, there are few studies that report on the relation between soil texture and chemical fertility of IBE. These soils of pre-Colombian origin, with high contents of P, Ca and other nutrients are found across the Amazon valley. IBE profiles were studied to evaluate the total contents of P, its primary chemical forms and the P transformation phases in areas with IBE soils of variable texture and in adjacent reference soils. The soil texture strongly influenced soil fertility, changing in terms of transformation of the primary P forms and, consequently, predominant P forms in IBE. Soils with texture varying between clay and heavy clay had higher total P contents and primary Ca-P forms. Highest P-Al and lowest total P amounts were observed at the site Rio Preto da Eva, where texture varies from sandy loam to sandy clay loam. In the IBE with clay texture the amounts of soluble P, extracted with NH4Cl were highest, although different from Mehlich 1-extractable amounts.

The genus Nothoscordum Kunth comprises approximately 20 species native to South America. Karyologically, the genus is remarkable for its large chromosomes and Robertsonian translocations. Variation in chromosome number has been recorded in a few polyploid species and it is unknown among diploids. This study presents the chromosome number and morphology of 53 individuals of seven populations of N. arenarium Herter (2n = 10). In addition, karyotype analyses after C-banding, staining with CMA and DAPI, and in situ hybridization with 5S and 45S rDNA probes were performed in six individuals from one population. All individuals exhibited 2n = 10 (6M + 4A), except for one tetraploid (2n = 20, 12M + 8A) and one triploid (2n = 15, 9M + 6A) plant. C-banding revealed the presence of CMA+/DAPI- heterochromatin in the short arm and in the proximal region of the long arm of all acrocentric chromosomes. The 45S rDNA sites co-localized with the CMA+ regions of the acrocentrics short arms, while the 5S rDNA probe only hybridized with the subterminal region of a pair of metacentric chromosomes. A change in the pattern of CMA bands and rDNA sites was observed in only one individual bearing a reciprocal translocation involving the long arm of a metacentric and the long arm of an acrocentric chromosome. These data suggest that, despite isolated cases of polyploidy and translocation, the karyotype of N. arenarium is very stable and the karyotypic instability described for other species may be associated with their polyploid condition.